Triangular Fibrocartilage Complex Abnormalities

Triangular Fibrocartilage Complex Abnormalities 

                                                       Dr KS Dhillon

Anatomy of the triangular fibrocartilage complex (TFCC)

The distal radioulnar joint (DRUJ) is stabilized by dorsal and volar radioulnar ligaments, the TFCC, and the joint capsule. The TFCC consists of five parts:

• The fibrocartilaginous disk and the meniscal homologue
• The ulnocarpal ligaments on the volar aspect (the ulnolunate
• and the ulnotriquetral ligaments 
• The dorsal and volar radioulnar ligaments (each with a
• superficial and deep part) 
• The ulnar collateral ligament
• The floor of the fibrous fifth and sixth extensor compartments

Eighty percent of the TFCC is represented by the central fibrocartilage disc which is avascular and consists of type 1 collagen fibres with fusiform chondrocytes in the matrix. The base of disk is attached to hyaline cartilage of the sigmoid notch of the distal radius and the apex is attached to the fovea at the base of the ulnar styloid on the head of the ulna. Like the menisci of the knee this central avascular portion of disc is unable to mount a reparative response. The peripheral 20% of the disk and its extensions: the ulnocarpal ligaments (volar), and the sheath of the extensor carpi ulnaris (dorsal) are vascularised. The peripheral portion which is vascular is capable of a reparative response.
On the medial side the disc continues and merges with the ulnar collateral ligament and on the volar side it merges with the ulnocarpal ligaments.
The ulnocarpal ligaments do not arise from the ulna. They in fact arise from the anterior part of the TFCC and they connect the carpus (lunate, triquetrum, and capitate) to the ulna by the palmar portion of the radioulnar ligament at its origin—the fovea. The radioulnar ligaments (dorsal and volar) arise from the medial aspect of the distal radius. They insert at different points onto the ulna (the deep fibers insert onto the fovea, whereas the superficial fibers insert onto the styloid process). There is a constant perforation of the meniscus homologue, named the prestyloid recess which may mimic a tear of the TFCC .            

Biomechanics
The TFCC plays a significant role in the biomechanics of the carpus and distal radioulnar joint (DRUJ). The TFCC serves the following functions:

• Stabilizes the DRUJ and the ulnocarpal joint.
• Transmission and distribution of forces from the wrist onto the ulna. It transmits 18% to 20% of the axial load across the wrist in the neutral position.
• Provide a gliding surface for the carpus during complex movements of the wrist. 
• Allows the distribution of mechanical stresses on the proximal part of the triquetrum and the lunate.

The proximal part of the TFCC acts as a DRUJ stabilizer while the distal part acts as a hammock which supports the ulnar carpus. Supination and pronation causes deformation of the central disk and the ulnar collateral ligament while the the triangular ligament twists significantly at its insertion on the ulna.

With pronation the head of ulna goes dorsal to the radius whereas in supination the head of ulna is relatively volar to the radius. The TFCC provides intrinsic stability to the DRUJ while the extrinsic stability is provided by the ECU subsheath, the distal fibers of the interosseous membrane, and the pronator quadratus muscle. The capsule of the DRUJ provides stability when there is extreme movements which can cause a dislocation of the DRUJ.

Prevalence of Triangular Fibrocartilage Complex Abnormalities

Abnormalities of the TFCC appear to be more common with age but the degree to which this is so remains controversial. The correlation between these abnormalities and symptoms also remains controversial [1]. Chan et al [1] performed a systematic review of the literature to determine the prevalence of triangular fibrocartilage complex abnormalities, and find out if the if the prevalence of abnormalities with increase age. They found that the the prevalence of triangular fibrocartilage complex abnormalities increased with age, from 27% in patients younger than 30 years to 49% in patients 70 years and older. In asymptomatic patients the prevalence  increased from 15% to 49% in the same age groups while the prevalence in symptomatic patients ranged from 39% to 70% in patients between 50 and 69 years old.
The authors concluded that TFCC abnormalities are common in both symptomatic and asymptomatic wrists, and that these abnormalities increase with age. Since the abnormalities are so common the finding of such abnormalities may be incidental. There is a dire need to find a reliable and accurate method to determine whether these abnormalities are the cause of the patients symptoms. There is also a dire need for evidence that treatment of these abnormalities relieves the patients symptoms better than a placebo [1].
The authors put up an interesting argument that the use of the word tear to describe abnormalities which are part of normal aging process may ‘reinforce the maladaptive coping strategy of catastrophic thinking’ where the word tear may suggest damage which need repair. It is likely in many situations that the TFCC abnormality is incidental to the cause of the patients symptom. Since the abnormalities are part of normal ageing process then surgery will potentially be unhelpful or unnecessary.

Diagnosis

There are several causes for ulnar side wrist pain and sometimes it can be difficult to pinpoint the exact cause of the pain. Some of the causes include [2]:

• Lunotriquetral instability
• Midcarpal instability
• Extensor carpi ulnaris (ECU) tendonitis/subluxation
• Flexor carpi ulnaris (FCU) tendinitis
• Arthritis: . a.Distal radioulnar joint (DRUJ) b. Pisotriquetral joint
• Fracture: a. Hook of the hamate b. Pisiform
• Hypothenar hammer syndrome
• More proximal lesions, e.g., a. Essex Lopresti lesion b. Cervical radiculopathy

In patients with TFCC tears, usually there is a history of fall on a pronated outstretched hand, a rotational injury to the forearm or a distraction injury to the ulna side of the wrist. The patient usually complains of ulnar side wrist pain with mechanical clicking on supination and pronation of the forearm. In patients with a tear of the articular disc, the will complain of discomfort on forearm pronation/supination, but without other complaints. Peripheral destabilizing tears of the TFCC cause more constant pain with activities of daily living, and examination shows limitation of range of motion [3]. The TFCC can be palpated between the ECU and the FCU, distal to the styloid and proximal to the pisiform. The only anatomical structure at this soft spot is the TFCC. The ulnar grind test is useful in making a diagnosis. It can be performed by dorsiflexion of the wrist, axial load, and ulnar deviation or rotation. If there is pain or mechanical symptoms during this provocative test a TFCC tear should be suspected.
In the differential diagnosis of ulnar sided wrist pain other causes should be ruled out before the diagnosis of a TFCC tear is made. Pisotriquetral joint/DRUJ arthritis can be ruled out by selective injections of these joints.
A 30 degree supinated oblique Xray show a fracture of the pisiform and a carpal tunnel view can show a fracture of the hook of the hamate. Pain on ballottement and shear can demonstrate instability of the lunotriquetral joint. A midcarpal clunk on examination can demonstrate midcarpal instability. A Allen test can confirm a hypothenar hammer syndrome (ulnar artery thrombosis) [3].

Radiographic evaluation

Radiographs of the wrist are taken with the arm abducted to 90 degrees and an PA and lateral view x ray is taken with the forearm in neutral position (zero rotation). The PA x-ray thus taken will provide the best view to measure ulnar variance. A pronated grip PA will show increased ulnar variance which can affect treatment decision. Tomaino [4] has demonstrated that a pronated grip PA view increased the ulnar variance by an average of 2.5 mm.
The value of MRI in the diagnosis remains controversial. Potter et al [5] using a high resolution MRI with a dedicated surface coil, small field of view (8 cm) and small (1 mm) slices showed a sensitivity of 100%, a specificity of 90%, and an accuracy of 97%. Their accuracy of localizing tears was 92%. Haims et al [6] have questioned the ability of the MRI to diagnose peripheral tears. They found a sensitivity of 17%, a specificity of 79% and an accuracy of only 64%. Blazar et al [7] showed that the experience of the musculoskeletal radiologist also plays an important role in the diagnosis. They found that there was a difference between the senior and a junior attending, in the accuracy of MRI diagnosis of TFCC tears. They found that the accuracy of diagnosis of a tear was 83% and 80% respectively, and the accuracy of localizing a tear was 69% vs. 37%. An  MRI can be a useful adjunct to history and clinical examination, but may not be as useful in determining the location of the TFCC tear [2].

Classification of TFCC tears

Palmer [8] in 1989 devised a classification system of TFCC tears to guide treatment. Palmer classified TFCC tears into two types i.e type I traumatic tears and type II atraumatic (degenerative) tears. Type I tears have been further subdivided into 4 types.

• Type IA (Avascular articular disc) tears which are the most common tears
• Type IB (Base of the styloid) tears where the rich vascularity of the periphery of the TFCC offers a highly favorable environment for healing
• Type IC (Carpal detachment) tears involve the ulnotriquetral or ulnolunate ligaments, volarly.
• Type ID (detachment from the ra“D”ius ) tears involve an avascular area of the TFCC as well.

Degenerative tears are usually caused by ulnocarpal impaction or excessive loading of the ulnar side of the wrist due to positive ulnar variance. In such situations a pronated grip PA radiograph of the wrist is useful in diagnosing a dynamic impaction [2].
Type II tears have an additive type of classification where each successive subtype adds one more finding [2]. 

• Type IIA tears. Thinning of the articular disk without frank perforation. 
• Type IIB tears. Thinning of articular disc with chondromalacia of the lunate or ulna. No click and mechanical symptoms since no tear or flap.
• Type IIC tears. Central perforation of disc with chondromalacia
• Type IID tears. Frank perforation, chondromalacia, and lunotriquetral ligament disruption.
• Type IIE tears. Perforation of the disc, chondromalacia, lunotriquetral ligament disruption and ulnocarpal arthritis

Treatment of TFCC tears

The anatomy of the TFCC and the differential diagnosis of ulnar wrist pain is complex while the treatment outcomes have not been well defined. This has prompted some to label the ‘ulnar side of the wrist as the "black box" of the wrist, and its pathology has been compared with that of low back pain’ [9].
The surgical outcome from intervention to address TFCC abnormalities are varied and it has not been clearly established that surgical interventions are better than the natural history since there are no sham surgery controlled trials [1]. There is high level (level I) evidence that arthroscopic joint debridement in patients with osteoarthritis of the knee and partial meniscectomy for degenerative partial meniscal tears is of no benefit to the patient [10,11]. We know that the placebo effect associated with surgery is usually very strong and we also know that ‘surgical interventions with entirely subjective outcomes (eg, pain) require sham surgery controls to be certain of their effectiveness’ [1]. Hence it is possible that the most of the surgical interventions for TFCC are ‘no better than regression to the mean, the natural history of wrist symptoms, or the placebo effect’ [1].
To confidently diagnose and treat TFCC abnormalities we have to certain about a few things. First, we must reliably and accurately be able distinguish between traumatic and nontraumatic anomalies. Secondly we must be certain that the particular abnormality is the cause of the patients symptoms and disability. Thirdly we must be able to show beyond doubt that the intervention we are embarking on is ‘better than the natural history of the disease and better than placebo interventions’ [1]. It remains difficult to point to TFCC abnormalities as the generator of wrist pain. Unfortunately to date, however, we are far from being able to overcome these hurdles in the management of patients with TFCC abnormalities. 

Natural History of TFCC tears

Mrkonjic et al [12] studied the long-term outcome of untreated TFCC tears in patients with displaced fractures of the distal radius. The study included 51 patients (24 men, 27 women; age, 20-57 y) with a displaced distal radius fracture who had wrist arthroscopy to identify associated injuries. Of the 51 patients 43 patients had complete or partial tears of the TFCC, which were not treated. The patients with TFCC tears were followed up for had a 13-15 years. One patient had surgery for painful instability of the wrist. The subjective and objective results in this study did not show that the TFCC tear influenced the long term outcome.
Deniz et al [13] studied the effect of untreated TFCC tear on the clinical outcome of conservatively treated distal radius fractures. They studied 47 consecutive patients with displaced radius distal fracture who were treated with closed reduction and casting. All patients underwent wrist MR imaging to detect traumatic TFCC tears. There was a TFCC tear in 24 cases, and the remaining 23 cases had no TFCC tear. At a mean follow up of 38.9 ± 3.5 months (range 36-48) there was no significant difference between groups in wrist function scores and radiographic measurements. The authors concluded that traumatic TFCC tears which are commonly seen with distal radius fractures do not affect the long-term functional results. Hence it would be unnecessary to do further tests for diagnosis and treatment of TFCC tears.

Conservative treatment

There is a dearth of literature on the conservative treatment of TFCC injuries. Conservative management of TFCC tears usually include splint/cast immobilization of the wrist and forearm for variable periods of time, usually about 4 weeks along with oral NSAIDs. Sometimes injections of corticosteroid are used and physiotherapy can be useful for pain relief and wrist mobilization [14].
 Park et al [15] in their study reported that 48 of their 84 patients with clinical diagnosis of TFCC injuries had complete pain relief with immobilization and about 43% of the patients with a clinical diagnosis of TFCC injury required surgical intervention after a minimum of 4 weeks of immobilization. This would suggest that conservative treatment would be the first treatment of choice for TFCC injuries.

Surgical treatment

The is extensive literature on the surgical treatment of TFCC abnormalities. Surgical interventions include débridement as well as acute and subacute repairs of the TFCC, which can usually be performed arthroscopically. An open ligament repair may sometimes be needed when there is distal radioulnar joint instability [14]. Other surgical options include ulnar diaphyseal shortening for more than 2 mm ulnar variance, wafer procedure where partial resection of the distal ulna is done for symptomatic tears of the TFCC or mild ulnar impaction syndrome or both and a Darrach procedure where a resection of the distal 1-2cm of the distal ulna is carried out for pain relief from an unstable DRUJ.

Arthroscopic débridement

Arthroscopic débridement of the TFCC is a commonly performed  therapeutic procedure for tears of TFCC in patients with a stable distal radioulnar joint and who have failed conservative treatment. There is a lack of consistency in the indications and effectiveness of arthroscopic débridement in the treatment of TFCC tears [16].
Saito et al [16] did a systematic review of literature to evaluate the effectiveness of débridement for TFCC tears. They identified 1723 studies related to the topic but only found 18 studies which were of value for studying the effectiveness of debridement in the of treatment of TFCC tears. Six studies showed a mean increase in the arc of wrist flexion/extension from 120 to 146 degrees. Ten studies showed a mean increase of grip strength from 65 percent and 91 percent after debridement as compared to the contralateral side. The patient reported outcome also improved after the surgery. Six studies showed an increase of Disabilities of the Arm, Shoulder, and Hand scores from 39 to 18 and 7 studies showed an increase in pain visual analogue scale scores from 7 to 3, respectively. Eighty-seven percent of patients returned to their preinjury work. The overall time to return to work was quite long and it averaged about 4 months. A low rate of workers’ compensation resulted in a high rate of return to original work and a high rate of workers’ compensation however resulted in a low rate of return to original work.
In patients without workers’ compensation, pain relief, wrist scores, and most objective measures of hand function are better than in patients with workers’ compensation [17].
The review also showed that further surgery was required in 31 percent of  patients who had positive ulnar variance and in 1 percent of patients with neutral or negative ulnar variance.
The authors of the review admitted that their review had several limitations due to the quality of evidence available in literature. The data available did not permit the authors to do a statistical analysis for the outcomes studied and they could not conduct a meta-analysis due the small numbers of articles available. Furthermore there were elements of publication bias in the articles available. The mean follow-up period in this review was 30 months, hence the long term outcome of could not assess. Since the studies in this review were all uncontrolled case series, the conclusions may be prone to publication bias which favors positive result [16].

Arthroscopic TFCC repair

There are several studies published which have reported good to excellent outcome following arthroscopic repair of the TFCC. However the studies involved small case series with short term outcome [18,19,20, 21].
As with arthroscopic debridement of the TFCC, there is no credible evidence to support the effectiveness of arthroscopic repairs of the TFCC in the treatment of patients with TFCC tears.

Salvage procedures

When there is impaction between ulna head and the ulnar carpal bones, ulnar impaction syndrome develops. There is usually positive ulnar variance which can lead to excessive load-bearing across the ulnar carpus, TFCC, and ulnar head leading to a degenerative/osteoarthritic condition of the ulnar side of the wrist, which produces ulnar sided wrist pain. In such situations an ulnar shortening procedure is performed by extra-articular ulnar shortening osteotomy or an arthroscopic intra-articular wafer resection of the ulna. This corrects the disparity between the lengths of the radius and ulna. Both these techniques can provide good outcome. However  patients who have ulnar shortening osteotomy run a risk of nonunion and sometimes there is a need for hardware removal. Sometimes more severe TFCC injuries require a Darrach (distal ulna resection) procedure or a Sauvé–Kapandji procedure where a DRUJ fusion with resection of a portion of the distal ulnar shaft is carried out to preserve forearm rotation [22].

Conclusion

The anatomy of the TFCC is complex. It consist of 5 parts, the largest part (80%) is the central fibrocartilage disc which is avascular  and cannot heal when it is injured. Just like the knee meniscus only the peripheral parts are vascular and can heal. The TFCC plays an important role in the biomechanics, of the carpus and distal radioulnar joint, by stabilizing the DRUJ and the ulnocarpal joint, as well as transmitting about 20% of the load across the wrist.
Abnormalities of the TFCC appear to be more common with age and the prevalence increases as we age. These abnormalities are present in both  symptomatic and asymptomatic wrists and this raises the possibility that the findings may be incidental and that surgery may potentially be unhelpful or unnecessary.
Although MRI of the wrist is useful in the diagnosis of TFCC abnormalities, its role remains controversial. TFCC tears can be traumatic or degenerative. The natural history of TFCC tears suggests that the presence of these tears does not affect the long term function of the wrist. Furthermore there is no irrefutable evidence that surgical treatment of TFCC tears is any better than no treatment. Some have equated the presences of TFCC abnormalities in the wrist to the presence of abnormalities in the aging spine where the role of surgery limited.

References

1. Chan JJ, Teunis T, and Ring D. Prevalence of Triangular Fibrocartilage Complex Abnormalities Regardless of Symptoms Rise With Age: Systematic Review and Pooled Analysis.  Clin Orthop Relat Res. 2014 Dec; 472(12): 3987–3994.
2.  Ahn AK, Chang D, and Plate AM. Triangular Fibrocartilage Complex Tears: A Review. Bulletin of the NYU Hospital for Joint Diseases. 2006; Volume 64, Numbers 3 & 4.
3. Raskin KB, Beldner S. Clinical examination of the distal ulna and surrounding structures. Hand Clin. 1998;14(2):177-90.
4. Tomaino MM. The importance of the pronated grip x-ray view in evaluating ulnar variance. J Hand Surg [Am]. 2000;25(2):352-7.
5. Potter HG, Asnis-Ernberg L, Weiland AJ, et al. The utility of high-resolution magnetic resonance imaging in the evaluation of the triangular fibrocartilage complex of the wrist. J Bone Joint Surg Am. 1997;79(11):1675-84.
6. Haims AH, Schweitzer ME, Morrison WB et al. Limitations of MR imaging in the diagnosis of peripheral tears of the triangular fibrocartilage or the wrist. AJR Am J Roentgenol. 2002;178(2):419-22.
7. Blazar PE, Chan PSH, Kneeland JB et al. The effect of observer experience on magnetic resonance imaging interpretation and localization of triangular fibrocartilage complex lesions. J Hand Surg [Am]. 2001;26:742-48.
8. Palmer AK. Triangular fibrocartilage complex lesions: A classification. J Hand Surg [Am]. 1989;14:594-606.
9. Sachar K. Ulnar-sided wrist pain: evaluation and treatment of triangular fibrocartilage complex tears, ulnocarpal impaction syndrome, and lunotriquetral ligament tears. J Hand Surg Am. 2008 Nov;33(9):1669-79.
10. Moseley JB, O'Malley K, Petersen NJ, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2002;347:81-88.
11. Sihvonen R, Paavola M, Malmivaara A, Itälä A, Joukainen A, Nurmi H, Kalske J, Järvinen TL, Finnish Degenerative Meniscal Lesion Study (FIDELITY) Group. Arthroscopic partial meniscectomy versus sham surgery for a degenerative meniscal tear. N Engl J Med. 2013 Dec 26; 369(26):2515-24.
12. Mrkonjic A, Geijer M, Lindau T, Tägil M. The natural course of traumatic triangular fibrocartilage complex tears in distal radial fractures: a 13-15 year follow-up of arthroscopically diagnosed but untreated injuries. J Hand Surg Am. 2012 Aug;37(8):1555-60.
13. Deniz G, Kose O, Yanik S, Colakoglu T, Tugay A. Effect of untreated triangular fibrocartilage complex (TFCC) tears on the clinical outcome of conservatively treated distal radius fractures. Eur J Orthop Surg Traumatol. 2014 Oct;24(7):1155-9.
14.  Henry MH. Management of acute triangular fibrocartilage complex injury of the wrist. J Am Acad Orthop Surg. 2008 Jun;16(6):320-9.
15. Park MJ, Jagadish A, Yao J. The rate of triangular fibrocartilage injuries requiring surgical intervention. Orthopedics. 2010 Nov 2;33(11):806.
16. Saito T, Malay S, Chung KC. A Systematic Review of Outcomes after Arthroscopic Débridement for Triangular Fibrocartilage Complex Tear. Plast Reconstr Surg. 2017 Nov;140(5):697e-708e.
17. Blackwell RE, Jemison DM, Foy BD. The holmium:yttrium aluminum-garnet laser in wrist arthroscopy: A five-year experience in the treatment of central triangular fibrocartilage complex tears by partial excision. J Hand Surg Am. 2001; 26:77–84.
18. Trumble TE, Gilbert M, Vedder N. Arthroscopic repair of the triangular fibrocartilage complex. Arthroscopy 1996;12: 588-597.
19.  Estrella EP, Hung L-K, Ho P-C, Tse WL. Arthroscopic repair of triangular fibrocartilage complex tears. Arthroscopy 2007;23:729-737.e1.
20. Yao J, Dantuluri P, Osterman AL. A novel technique of all-inside arthroscopic triangular fibrocartilage complex repair. Arthroscopy 2007;23:1357.e1-1357.e4
21. Wysocki RW, Richard MJ, Crowe MM, Leversedge FJ, Ruch DS. Arthroscopic treatment of peripheral triangular fibrocartilage complex tears with the deep fibers intact. J Hand Surg Am 2012;37:509-516.
22. Watanabe A, Souza F, Vezeridis PS, Blazar P, Yoshioka H. Ulnar-sided wrist pain. II. Clinical imaging and treatment. Skeletal Radiology. 2010;39(9):837-857. doi:10.1007/s00256-009-0842-3. 

Traumatic Brachial Plexus Injuries in Adults

                                  Traumatic Brachial Plexus Injuries in Adults

                                                                 Dr KS Dhillon

 Brachial plexus anatomy

The brachial plexus is formed by the ventral/anterior rami of the C5, C6, C7, C8, and T1 spinal nerve roots. There are normal variations, where the C4 root (prefixed) and the T2 root (postfixed) may contribute to the formation of the plexus. The five roots terminate in five nerves which provide motor and sensory innervation to the upper limb. This 5 nerves include the musculocutaneous, median, ulnar, axillary, and radial nerves. The portion the plexus between the roots and the nerves consists of 3 trunks, 3 divisions and 3 cords (sets of 3).
The trunks include the superior (C5,C6), middle (C7) and inferior (C8,T1). Each trunk divides into two divisions, the anterior (3) and posterior (3) divisions. The divisions form 3 cords, the medial (C8,T1), lateral (C5-C7) and posterior (C5 -T1). Each cord gives rise to 2 branches.The posterior cord divides into the axillary and the radial nerves and the lateral cord divides into the musculocutaneous nerve and the lateral branch of the median nerve. The medial cord divides into the medial branch of the median nerve and the ulnar nerve.
The musculocutaneous nerve (C5,6 and 7) provides motor innervation to the coracobrachialis, biceps and the medial brachialis and sensory innervation to the lateral forearm via the lateral antebrachial cutaneous nerve.
The axillary nerve (C5,C6) supplies the motor innervation to the Deltoid and the Teres Minor muscles and sensation to the lateral shoulder via the superficial lateral cutaneous nerve of arm.                   
The ulnar nerve (C7,C8,T1) provides motor innervations to the following muscles, Flexor carpi ulnaris, Flexor carpi profundus to ring and little finger, adductor pollicis, deep head of flexor pollicis brevis (FPB),interossei (dorsal and palmar), 3rd & 4th lumbricals, abductor digiti minimi, opponens digiti minimi and flexor digiti minimi. It provides sensory innervation to the ulna aspect of the dorsum of the hand and dorsum of the little finger and ulnar  aspect of the ring finger via the dorsal dorsal  aspect of the ring finger via the dorsal dorsal cutaneous branch and hypothenar region of the hand via the palmar cutaneous branch and the palmar aspect of the little finger and ulnar side of the ring finger via the superficial terminal branches.           
The radial nerve (C5-T1) provides motor innervation to the triceps, anconeus, extensor carpi radialis longus and brevis and the brachioradialis.
 The posterior interosseous branch innervates the extensor digitorum, supinator, extensor digitorum minimi, extensor carpi ulnaris, abductor pollicis longus, extensor pollicis longus and brevis and the extensor indicis proprius. The radial nerve provides sensory supply to the posterior aspect of the arm, forearm and the radial aspect of the extensor aspect of the hand and the thumb, index, middle and radial aspect of the ring finger via the posterior cutaneous nerve arm, posterior cutaneous nerve of the forearm, superficial branch radial nerve and the dorsal digital branch.
The median nerve (C5-T1) provides motor innervation to the, Pronator teres, Flexor carpi radialis, Palmaris longus, Flexor digitorum superficialis,  Flexor digitorum profundus (lateral), Flexor pollicis longus, Pronator quadratus, 1st and 2nd lumbricals, Opponens pollicis, Abductor pollicis brevis and the Flexor pollicis brevis. It provides sensory supply to the lateral palm via the palmar cutaneous branch and the radial 3 and half digits (palmar) and can also supply the index, middle, and ring fingers dorsally via the digital cutaneous branches.

Epidemiology

There is a scarcity of literature on the epidemiology of traumatic brachial plexus injuries. Midha reported a 1.2% incidence in 4538 patients with polytrauma [1]. In winter sports injuries the incidence is about 4.8% and after motorcycle collisions it is about 4.2% [1].
The majority of the brachial plexus injuries involve the upper brachial plexus. In about 725 of the cases there is upper plexus palsy and in 26% of the cases there is a complete plexus palsy. Lower plexus palsies are seen in about 2% of the cases [2].

Mechanism of injury

The severity,extent and level of traumatic brachial plexus injuries (BPIs) can vary depending on the degree and direction of the force involved. The
more severe injuries such as rupture of plexal segments or root avulsions are usually associated with higher energy trauma.
High speed vehicular accidents (mostly motorcycle) are responsible for about 83% of traumatic BPIs. A caudally directed force on the  shoulder
predominantly affects the upper brachial plexus and  forced arm abduction (as in grabbing onto something while falling) usually affects lower roots. If the force is severe all roots may be involved [3].

Preganglionic and postganglionic brachial lesions

It is important to locate the level of brachial plexus lesion in relation the ganglion of the dorsal root because the approach to pre and postganglionic injuries is often different. Some postganglionic lesions can recover spontaneously, but preganglionic lesions have no capacity to regenerate and can never heal and they should be identified as soon as possible.
Supraclavicular brachial plexus lesions can be preganglionic or postganglionic but infraclavicular lesions are always postganglionic.
Supraclavicular lesions have a myotome/dermatome distribution whereas postganglionic proximal peripheral distribution. The upper roots (C5,6) are most frequently injured and the upper root lesions are usually postganglionic whereas lower root (C8,T1) are usually preganglionic.
The upper roots are usually protected against avulsion by the branches of the nerves and the the interscalene ligaments. There are fibrous attachments that at the C4 to C7 levels, which tie spinal nerves down to transverse processes, after their exit from intervertebral foramina which
also protect them against avulsion. About 60% of upper root lesions are ruptures and 40% avulsions. The lower roots (C8,T1) lesions are more often preganglionic since the roots are in the direct line of pull to the spinal cord. There is not protection against avulsion for the C8 and T1 roots. Eighty five percent of the lesions are avulsions and about 15% of lower root lesions are ruptures.                           
                           

Root avulsion (preganglionic lesion) should be suspected when the patient reports ‘constrictive or caustic pain in an otherwise insensitive upper limb’ and when clinical examination shows the presence of a Horner’s syndrome and paralysis of the scapular muscles, serratus anterior, and rhomboids. The dorsal scapular as well as long thoracic nerve which supply these muscles are formed just distally to the roots. The presence of Horner’s syndrome (lid ptosis, miosis, enophthalmos, and hemifacial anhidrosis) indicates the that the T1 sympathetic ganglion is injured and this ganglion is close to the T1 root and avulsion injuries occur frequently to both these two structures together [4]. The presences of phrenic nerve injury (paralysis
of the ipsilateral hemidiaphragm) may also be suggestive of a preganglionic lesion since the nerve originates just distal to the roots.         
                           

Clinical diagnosis of brachial palsy

Upper brachial plexus palsy

The upper brachial plexus palsy involving C5, C6 roots has been described as “bad shoulder, good hand” palsy. It is also known as the Erb’s palsy where there is a paralysis of the shoulder abductors (deltoid, supraspinatus), external rotator (infraspinatus), elbow flexors, supinator and the wrist extensor, resulting in ‘waiter’s tip’ upper limb. The rhomboids and serratus anterior is usually spared. There is axillary nerve, suprascapular nerve and radial nerve deficiency due to C5,C6 involvement. The arm is usually held adducted, internally rotated at the shoulder and  extended at the elbow with the wrist flexed.

Intermediate plexus palsy (C7)

Intermediate plexus lesion rarely occur in isolation. They usually occur with upper and lower plexus lesions. C7 lesions in isolation have minimal impact on upper limb function. It usually produces some weakness of wrist extension.

Lower plexus palsy (C8,T1)

Lower plexus palsy involving the C8,T1 roots is often described as the ‘good shoulder, bad hand’ palsy. If it is a preganglionic lesion, a Horner’s syndrome is usually present. Lower plexus lesion produces weakness FCU, FDP to ulnar digits, loss of hand intrinsics function, loss of EIP and EPL function and medial forearm and hand sensory loss.

Panplexus (C5-T1)

In a panplexus palsy all roots of the brachial plexus from C5 to T1 are involved.

Motor testing 

Terminal branches of brachial plexus and their function.

1.Dorsal Scapular nerve (C5).  It supplies the Rhomboids which stabilize the scapula
2.Long Thoracic nerve (C5). It supplies the Serratus Anterior which abducts the scapula
3.Suprascapular nerve (C5). It supplies the Supraspinatus which abducts the shoulder and the Infraspinatus which externally rotates the shoulder.
4. Medial (C8) and Lateral Pectoral (C7) nerves. Both nerves supply the Pectoralis Major which adducts and medially rotates the upper limb. The Pectoralis Minor is supplied by the Medial Pectoral nerve and it stabilizes the scapula.
5.Subscapular nerve (C5). It supplies the Subscapularis and the Teres Major which produce internal rotation of the shoulder.
6.Thoracodorsal nerve (C7). It supplies the Latissimus Dorsi which adducts the shoulder.
7.Musculocutaneous nerve (C5). It supplies the Biceps brachii and the Brachialis which flex the elbow.
8.Ulnar nerve (C8,T1) . It supplies the Flexor carpi ulnaris and Intrinsic muscles of hand which helps in wrist flexion and flexion of ring and little fingers as well as abduction of all fingers.
9. Median nerve (C6-T1). It supplies the pronatus and the flexors of the wrist and fingers (index and middle).
10. Radial nerve (C6-C8). It supplies the supinator, triceps and extensors of the wrist and fingers.
11. Axillary  nerve (C5). It supplies the Deltoid and the Teres minor which abduct the shoulder.

Sensory testing

The C5 root supplies the skin over the deltoid, the C6 provides sensation to the thumb and index finger. The middle finger sensation is provided by the C7 and the little and part of ring finger sensation is provided by the C8 root. The T1 root provides sensation to the medial side of the forearm while the T2 root provides sensation to the inner side of the arm.

Electrodiagnostic Tests

Electrodiagnostic tests are useful in confirming the diagnosis, localization of the lesion, determining the severity of axial discontinuity, and eliminating other causes for the clinical findings. Electrodiagnostic tests are always used in conjunction with a meticulous physical examination in the management of patients with suspected brachial plexus injuries.
Electromyography (EMG) and nerve conduction velocity studies (NCSs) are usually performed 3 to 4 weeks after the injury by when Wallerian degeneration has completed in postganglionic lesions and the conduction of potentials along the nerves have stopped. Serial testing will provide information about reinnervation or continued denervation.

Electromyography

Electromyography evaluates and records electrical activity produced by muscles. A needle electrode is inserted through the skin into the muscle that is being studied. The nerve supplying the muscle is stimulated and electromyogram detects the tiny amount of electricity generated by muscle cells. The EMG tests muscles at rest and during activity. The denervation fibrillation potentials can be seen as early as 10 to 14 days after injury in proximal muscles and as late as 3 to 6 weeks in distal muscles. When voluntary motor unit potentials with limited fibrillation potentials are present it signifies better prognosis than the cases where there is a complete absence of motor unit potentials and many fibrillation potentials.
Abnormalities of EMG can be seen in any condition which damages the anterior horn cell body, axon, Schwann cells, the neuromuscular junction, or the muscle cell itself. The size, shape, and morphology of the action potential can help determine the state of myelination, the number of functioning muscle fibers, and the function of the neuromuscular junction. Since the cell body of motor nerves is located in the anterior horn cell within the spinal cord the motor nerve conduction is abnormal in both preganglionic and postganglionic lesions.

Sensory nerve conduction studies

Sensory nerve conduction studies are performed by stimulation of a peripheral nerve (sufficient to produce an action potential) at one point while the action potential is measured at another point along the course of the nerve. The latency, conduction velocity, and amplitude of the action potential are analysed. The information obtained can localise the level of the lesion and help differentiate between preganglionic disorders (eg, radiculopathies, cauda equina lesions, posterior column disease) from postganglionic disorders (eg, neuropathies, plexopathies). In patients with  preganglionic lesion, the sensory nerve action potential is normal (although clinically abnormal) because axonal transport from the cell body to the peripheral axon remains intact and in patients with postganglionic lesions sensory nerve action potential will be abnormal [5].

Radiological investigations

In patients with traumatic brachial plexus injuries, plain xrays of the neck and shoulder may be useful to look for associated injuries to cervical spine and to look for fractures of the clavicle and the surrounding region. A transverse process fracture of the cervical vertebrae is likely to indicate a root avulsion. A scapulothoracic dissociation is also associated with root avulsion. The X Rays will also show the presences of any shrapnel in patients with gunshot injuries. An inspirational and expirational chest X Ray film would be useful to exclude hemidiaphragm paralysis due to a phrenic nerve palsy.
In the past CT-myelography was considered as the "gold standard" for studying root lesions, but now with recent advances in magnetic resonance imaging (MRI), MRIs of the cervical spine can the diagnostic accuracy of CT-myelography [6]. Cervical MRIs provide a non-invasive means of detecting nerve root avulsions and the scans can also show the presences of pseudomeningoceles (sign of root avulsion) and spinal cord edema (an indirect sign of nerve root avulsion) [7]. MR neurography is very useful in imaging the brachial plexus for injuries.

Treatment of Brachial plexus injuries

Open injuries 

Open injuries of the brachial plexus, though uncommon, require exploration at the earliest opportunity available. Injuries with associated vascular injuries also require emergency operation. In cases of sharp laceration of the neural structures an end to end repair of the structures is carried out. In cases of blunt laceration, the nerve is fixed to adjacent tissues to reduce  retraction and secondary repair is carried out two to three weeks later. This delay allows demarcation of the damaged neural tissue. If direct repair is not possible than nerve grafting is carried out.
Open high-velocity gunshot wounds are usually associated with significant soft-tissue damage and such wounds require early surgical exploration. On the other hand low energy civilian gunshot wounds do not have to be explored immediately because such injuries are usually associated with neuropraxia of neural structures where spontaneous recovery is possible [8]. Such injuries are usually explored after 3-4 months if no recovery occurs.

Close injuries

Close injuries of the brachial plexus are initially managed conservatively. The treatment includes pain management as well as therapy to mobilise the joints to prevent contractures and maintenance of strength of the uninvolved muscles. EMG can be considered after one month for more accurate evaluation of the brachial plexus lesion. Surgery is usually considered if there is no recovery after 3 to 6 months.
Management of pain can be difficult. Pain is most severe in patients who have complete lesions and when the lesions are preganglionic. The pain is often excruciating and exhausting. In the initially stages NSAIDs and opioids can used but antiepileptic drugs (gabapentin and carbamazepine) or antidepressants such as amitriptyline may be needed for neuropathic pain. Other modes of treatment such as biofeedback, punctuation, hypnosis, and percutaneous nerve stimulation have been used with some success [9].

Surgical treatment

Surgery is always performed under general anesthesia without the use of any muscle-blocking agents and the plexus is exposed through an anterior supraclavicular, infraclavicular, or a combined approach. Various operative techniques are used depending on the findings at the time of surgical exposure of the plexus.

Neurolysis

The presence, location and the extent of neuroma is noted and a direct bipolar electrical stimulation is carried out. A visual evaluation of muscle contraction is observed. When there is doubt about visual contraction of the muscles, than concentric needle electrodes are used for intraoperative electromyography evaluation of the motor response. If there is sufficient muscle response to electrical stimulation proximal to the neuroma then neurolysis is carried out [10]. All attempts are made to maintain the interfascicular structure and the nerve sheath during neurolysis. Interfascicular neurolysis is avoided so as to prevent vascular damage. An anterior epineurotomy is usually performed and the fibrous tissue is excised.
In the absence of any useful response to electrical stimulation the neuroma is exicised a little at a time till the neural ends are identified. The neural ends are then suture together. However if the gap is too wide for end to end suture, then a nerve graft is used to to fill the gap. The usual source of nerve graft is one or both sural nerves. Sural nerve is usually used as a graft material because removal of the sural nerve does not produce any significant deficit. The other nerves often used as graft material include the sensory branch of ulnar nerve, and the medial cutaneous nerve of the forearm. A success rate of 79% with a direct repair has been reported with evidence of reinnervation as measured by EMG at 12 months follow up [11].

Nerve transfer (neurotization)

Nerve transfer or neurotization involves the transfer of a functional but less important nerve to a non functional but more important recipient nerve. It is usually done for root avulsions and intractable proximal brachial plexus injuries. The choice of donor nerves for neurotization remains controversial [10]. There are two categories donor nerves for neurotization namely the extraplexal and intraplexal nerves.
For complete avulsion of the cervical roots forming the brachial plexus, only extraplexal nerves such as the accessory nerve, motor branches of the cervical plexus, intercostal nerves and the phrenic nerve are available for neurotization. Intraplexal nerves as donors for motor fibres can be derived from thoracodorsal nerve, the long thoracic nerve, and the pectoral nerves. The use of intraplexal nerves provides more favourable results as compared to that obtained with extraplexal nerves [11].

Fascicular transfer

More recently neurotization is being performed using only a part of the donor nerve. It involves the transfer of fascicles of a functional nerve to a non functional nerve. To restore deltoid function fascicles of the radial nerve to the triceps are transferred to the axillary nerve. With this transfer the effect on the triceps is negligible [12]. Oberlin introduced a neurotization technique where an ulnar nerve fascicle is transferred to the branch of the musculocutaneous nerve for biceps function thereby restoring flexion of elbow in patients with upper brachial plexus injuries without significant motor or sensory deficits of the ulnar nerve [13]. For this technique of restoration of elbow function the lower brachial plexus has to be intact since the ulnar nerve is formed from the C8 and T1 roots.
 Songcharoen in 2001,described a technique where a median nerve fascicle is used to repair the musculocutaneous nerve and restore biceps muscle function [14].

End-to-side neurorrhaphy

In patients with combined supra- and infraclavicular brachial plexus injuries the proximal stump of an injured nerve is often unavailable or the nerve gap is too long to be bridged by a nerve graft. In such injuries the commonly used donor nerves are not available for nerve repair. To overcome the problem in such cases the distal stump of the transected nerve is coapted to adjacent donor by end-to-side neurorrhaphy. There is evidence to suggest that end-to-side neurorrhaphy can provide satisfactory functional outcome for the recipient nerve without affecting the function of the donor nerve. With this technique of end-to-side neurorrhaphy there is no need need to sacrifice the surrounding nerves or their fascicles.

Secondary Operations

In the event that no recovery occurs either spontaneously or following  surgical procedures involving the nerves, then secondary procedures may be required to improve the limb function. Some of the options include arthrodesis, tendon transfers and functional free muscle transplantation.

Arthrodesis

In patients with upper brachial plexus paralysis where the shoulder is unstable and painful an arthrodesis of the shoulder (glenohumeral arthrodesis) can improve function of the limb. The prerequisite for shoulder arthrodesis is good thoracic-shoulder functionality and intact acromioclavicular joint, sternoclavicular joint, and scapulothoracic joints. The shoulder is usually fused in 30 degrees of abduction, 30 degrees flexion, and 30 degrees of internal rotation (33-30-30 positioning). This allows about 60 degrees abduction and flexion with the scapulothoracic movements[15].
Wrist arthrodesis is sometimes done when there is flexion deformity of the wrist due to wrist extensor paralysis. Occasionally carpometacarpal arthrodesis of the thumb is done to improve hand function.

Osteotomy

Derotation osteotomies of the humerus and the forearm are sometimes done to correct internal rotation deformity of the arm and forearm.

Tendon Transfers

Tendon transfers are carried out for partial upper or lower plexus paralysis. For restoration of shoulder abduction a trapezius transfer to the deltoid or an anterior transfer of the posterior deltoid can be carried out. A latissimus dorsi transfer can be carried out to improve external rotation of the shoulder.
Restoration of elbow flexion is very important for a good clinical and functional outcome. The commonly used transfers for restoration of elbow flexion include Steindler’s proximal transfer of common origin of forearm flexors, transfer of triceps to the biceps, latissimus dorsi transfer to the tendon of the biceps brachialis and the Clark’s transfer of pectoralis major brachial branch tendon to brachial bicep [9].

Functioning Free Muscle Transplantation

The gracilis muscle transplantation with microvascular anastomosis and microneural coaptation to the recipient motor nerve has been used in many patients to restore elbow and finger flexion and extension. The accessory nerve and or the intercostal nerves are used as donor nerves. Both the gracilis muscles can be sacrificed with any significant functional loss.

Prognosis of brachial plexus injuries

Injuries in young individuals below 30 years generally have better prognosis. The more distal the injury better the prognosis. Patients with incomplete lesions do better than those with complete lesions. Patients with preganglionic lesions and those with vascular injury have poorer prognosis.

References

1. Midha R. Epidemiology of brachial plexus injuries in a multitrauma population. Neurosurgery. 1997;40(6):1182–1189.
2. Kaiser R, Mencl L, Haninec P. Injuries associated with serious brachial plexus involvement in polytrauma among patients requiring surgical repair. Injury. 2014; 45(1):223–226.
3. Jason McKean. Brachial Plexus Injuries at https://www.orthobullets.com/trauma/1008/brachial-plexus-injuries. Accessed on 8/12/2017.
4. Vasileios I. Sakellariou, Nikolaos K. Badilas, George A. Mazis, et al., “Brachial Plexus Injuries in Adults: Evaluation and Diagnostic Approach,” ISRN Orthopedics, vol. 2014, Article ID 726103, 9 pages, 2014. doi:10.1155/2014/726103.
5. Aminoff MJ. Aminoff's electrodiagnosis in clinical neurology. 6th ed. Saunders: Philadelphia; 2012.
6. Doi K, Otsuka K, Okamoto Y, Fujii H, Hattori Y, Baliarsing AS. Cervical nerve root avulsion in brachial plexus injuries: magnetic resonance imaging classification and comparison with myelography and computerized tomography myelography. J Neurosurg 2002;96:277-284.
7. Siqueira Mario G., Martins Roberto S.. Surgical treatment of adult traumatic brachial plexus injuries: an overview. Arq. Neuro-Psiquiatr.  [Internet]. 2011  June [cited  2017  Dec  13] ;  69( 3 ): 528-535.
8. D. G. Kline, “Civilian gunshot wounds to the brachial plexus,” Journal of Neurosurgery, vol. 70, no. 2, pp. 166–174, 1989.
9. Vasileios I. Sakellariou, Nikolaos K. Badilas, Nikolaos A. Stavropoulos, et al., “Treatment Options for Brachial Plexus Injuries,” ISRN Orthopedics, vol. 2014, Article ID 314137, 10 pages, 2014. doi:10.1155/2014/314137.
10. Pavel Haninec and Libor Mencl. Surgical Treatment of Brachial Plexus Injury at http://dx.doi.org/10.5772/intechopen.68442. Accessed on 16/12/17.
11. Haninec P, et al. Direct repair (nerve grafting), neurotization, and end-to-side neurorrhaphy in the treatment of brachial plexus injury. Journal of Neurosurgery. 2007;106 (3):391–399.
12. Leechavengvongs S, et al. Nerve transfer to deltoid muscle using the nerve to the long head of the triceps, part II: A report of 7 cases. The Journal of Hand Surgery. 2003;28(4):633–638.
13. Oberlin C, et al. Nerve transfer to biceps muscle using a part of ulnar nerve for C5–C6 avulsion of the brachial plexus: Anatomical study and report of four cases. The Journal of Hand Surgery. 1994;19(2):232–237.
14. Songcharoen P. Management of brachial plexus injury in adults. Scandinavian Journal of Surgery. 2008;97(4):317–323.
15. E. Rouholamin, J. R. Wootton, and A. M. Jamieson, “Arthrodesis of the shoulder following brachial plexus injury,” Injury, vol. 22, no. 4, pp. 271–274, 1991.

Eugenics the Past,Present and Future

                Eugenics the Past,Present and Future

                                                   Dr KS Dhillon

Definition

The Oxford dictionary defines eugenics as ‘the science of improving a population by controlled breeding to increase the occurrence of desirable heritable characteristics’ [1]. The Merriam-Webster dictionary defines eugenics as ‘a science that deals with the improvement (as by control of human mating) of hereditary qualities of a race or breed’ [2]. Dictionary.com gives a more comprehensive definition of eugenics and describes it as ‘the study of or belief in the possibility of improving the qualities of the human species or a human population, especially by such means as discouraging reproduction by persons having genetic defects or presumed to have inheritable undesirable traits (negative eugenics) or encouraging reproduction by persons presumed to have inheritable desirable traits (positive eugenics) [3].

The British Eugenics movement

The word eugenics is derived from Greek roots for ‘eu- good, well’ and ‘gen- genesis, creation’. Although some form of eugenics was practiced by Hindus 7,000 years ago, it was Francis Galton who first coined the term eugenics in 1800’s and he was the pioneer who developed the subject of eugenics. He defined eugenics as "the science of improving the inherited stock, not only by judicious matings, but by all other influences ..." [4].
Modern science has now ’expanded the definition of eugenics and expressed it as "the use of science applied to the quantitative and qualitative improvement of the human genome" [5]; whereby population numbers can be regulated and genome quality can be improved ‘by selective artificial insemination by donor, gene therapy or gene manipulation of germ-line cells [6].
Galton (1822-1911) was an English intellectual who was a half cousin of Charles Darwin. Galton’s work spanned various specialities including statistics, psychology, meteorology as well as genetics. His first foray into eugenics was when he studied the pedigrees of England’s upper class families from biographical information obtained from obituaries and other sources and concluded that ‘superior intelligence and abilities were inherited with an efficiency of 20%’ [7]. In his book Hereditary Genius (1869) he advocated a selective breeding program for humans. He believed that as horses and dogs can be bred for superior ability in running or other abilities, similarly humans can be bred to produce highly-gifted individuals by judicious marriages over several generations.
In 1904, Galton, established a research fellowship in eugenics at University College London (UCL), and the Eugenics Record Office (ERO) was installed in Gower Street London.The ERO was later renamed as the Galton Laboratory of National Eugenics. In 1907 a group of Galton followers founded the Eugenics Education Society (EES) [8].
The objectives of the society were;

• ‘Persistently to set forth the National Importance of Eugenics in order to modify public opinion, and create a sense of responsibility in the respect of bringing all matters pertaining to human parenthood under the domination of Eugenic Ideals’.
• ‘To spread a knowledge of the Laws of heredity so far as they are surely known, and so far as that knowledge might affect the improvement of the race’.
• ‘To further Eugenic Teaching, at home, in the schools, and elsewhere’[9].

Eugenics movement in the United States

Galton’s thoughts on eugenics gained traction both in England and in United States. Charles Davenport (1866-1944), a prominent american biologist, took the lead in United States to further advance the study of eugenics. He established the Eugenics Record Office (ERO) on Long Island, New York, USA and their goal was “to improve the natural, physical, mental, and temperamental qualities of the human family” [7]. The ERO collected data depicting the inheritance of physical, mental, and moral traits in family pedigrees. Their main interest was in negative and undesirable traits such as criminality, dwarfism, pauperism, promiscuity and mental disability. Their studies unveiled valuable information about the inheritance of conditions such as albinism and neurofibromatosis [7].
The genetic knowledge available in the 1900’s was sufficient to encourage the use of genetics for altering the human gene pool. The scientific basis of these attempts to alter the genetic pool was the Mendelian demonstration of dominant and recessive inheritance in peas which allowed for ‘prediction of phenotypes among offspring of parents with known genotypes’ [7]. In fact  animal breeders have been selectively breeding  animals to improve their livestock for many centuries.
Eugenics enthusiasts thought that if it was possible in plants and animals, why was it not possible to apply the same principles to improve human population? They thought that by controlling human mating they could eliminate mental illness, mental retardation as well as  disabling physical ailments.
The elimination of undesirable genes from the population, however, involved preventing individuals with such genes from having children and this would involve involuntary sterilization or institutionalization
Soon eugenics became a public health issue which got not only scientist but also doctors and lawmakers involved [7]. The eugenics movement in the United States peaked in the 1920s and 1930s. It saw the founding of the American Eugenics Society and other local societies and groups. Fairs, exhibitions, books and movies promoted eugenics [7].
In 1917, even a film, The Black Stork, was released which depicted a fictional account of a true story of eugenic infanticide. It was based on Dr Haiselden real life experience where he allowed an infant (John Bollinger) suffering from syphilis to die after he convinced the parents that the child would grow up to be a miserable outcast and that death was the best option for the child and for society.
Dr Haiselden was charged for allowing Bollinger to die but the jury acquitted him and the Illinois State Board of Health also dropped action to revoke his medical licence. The Chicago Medical Society however did terminate his membership because of The Black Stork and the publicity he sought out after the infanticide [10].
Dr. Haiselden was an ardent, outspoken supporter of the eugenics and after the Bollinger infanticide he became famous despite the extensive controversy it created. From then on he took eugenics to the national stage.
Although the eugenics enthusiasts in England led by Galton promoted selective breeding for positive traits, the American eugenics movement promoted elimination of negative traits. Unfortunately these negative traits were found among the uneducated, poor, minority population. To prevent such people from propagating eugenic enthusiasts pushed for legislations for their forced sterilization. This push resulted in legislation in Indiana in 1907, followed by California and 28 other states by 1931 [11]. These laws resulted in forced sterilization of over 64,000 people in the United States [11].
Sterilization efforts initially started with sterilization of the disabled but eventually included people who were simply poor. These sterilization programs though flawed in science and principle found support in the Supreme Court of United States in Buck v. Bell (1927).
In Buck vs. Bell decision of May 2, 1927, the United States Supreme Court upheld a Virginia statute that provided for the eugenic sterilization for people considered genetically unfit.
The Virginia state had sought to sterilize Carrie Buck for promiscuity because she had given birth to a child (Vivian) out of wedlock. In ruling against Carrie Buck, Supreme Court Justice Wendell Holmes opined, “It is better for all the world, if instead of waiting to execute degenerate offspring for crime, or to let them starve for imbecility, society can prevent those who are manifestly unfit from continuing their kind....Three generations of imbeciles is enough” [12].
This supreme court decision legitimized the sterilization laws in the USA with California having one of the most robust program. Even Nazi Germany under Hitler turned to California for advice in perfecting their own efforts for the prevention of reproduction of the “unfit”[12].
The sterilization program got a boost from the Supreme Court decision although the decision in Buck vs. Bell according to some was flawed in many ways. According to critics, feeblemindedness is a vague term with no medical or clinical meaning and it was impossible in 1927 with the information available to judge if Carrie was feebleminded. Carrie was apparently not promiscuous and Vivian was conceived as result of rape by by the nephew of her foster parents. Neither was Vivian an an imbecile. Vivian's first grade report card showed excellent grades and she made the honor roll in 1931. Unfortunately she died a year later  from measles complications [13].
In 1942 the Supreme Court struck down a law which allowed involuntary sterilization of criminals. It however did not reverse the general concept of eugenic sterilization. After many years in 2001, realization dawned and the Virginia General Assembly did acknowledged that the sterilization law was based on faulty science. The General Assembly expressed its "profound regret over the Commonwealth's role in the eugenics movement in this country and over the damage done in the name of eugenics” [13].

Problems with Eugenic Studies

It was believed that one of the problems with the eugenics movement was that most of the traits studied by the eugenicists had little or no scientific or genetic basis. The characteristics commonly studied in those days for elimination from the human population were traits such as "criminality," epilepsy, bipolar disorder, alcoholism, and "feeblemindedness,"[7] which were believed to be more related to environmental factors (such as poor housing, poor nutrition, and inadequate education) [7].
However recent studies do show that many of these disorders have familial or genetic links which suggests that eugenicists those days were quite right despite the lack of scientific evidence.
In severe forms of mental retardation genetics play a very important role but in mild forms of mental retardation, genetics does sometimes play a role with cultural factors playing a significant role. Two genetic disorders with mental retardation have been identified namely Rett syndrome and the Williams syndrome [14].
Studies have also found ‘compelling evidence that schizophrenia and bipolar disorder partially share common genetic etiology’[15]. Even for epilepsy genetic factors responsible for the disease have been identified [16].
There is now evidence that ‘personality disorders are moderately to strongly heritable (heritability estimates between 30% and 80%) and that environmental factors increase the risk of personality disorder’[17].
Though there has been some who believe that criminality is a hereditary trait, others would call the idea of ‘criminal gene' as nonsense, but now there is ‘growing evidence that some psychopathic behaviour might indeed be grounded in genes’ [18].
There is some evidence, though not robust, that the ADH1B and ALDH2 genes are strongly associated with risk for alcoholism [19].
Charles Davenport’s Eugenics Record Office (ERO), over a span of 29 years, in the early 1900’s collected ‘hundreds of thousands of pedigrees that documented the heritability of ….. undesirable traits’[7]. Information was obtained from interview with families and from records kept by prisons and psychiatric hospitals [7]. The data thus obtained was considered to be unscientific and bad science, yet popular support continued to grow. The believe that the data obtained was flawed lead to discreditation of the eugenics movement by the 1930s. However, we now know that much of what was believed in those days, based on so called flawed, unscientific data, was true. There is now more scientific proof that many of those undesirable traits have a genetic basis.

Eugenic movement in Germany

In 1932 the Weimar government (Germany) drafted a plan for sterilizations of individuals with "hereditary illnesses" and this plan was inspired by eugenic movement in the USA. After the First World War the cost of maintaining many people who were living in institutions was becoming a burden on the government and it was felt that sterilizing them would prevent them from having children and be cost effective. Under this program involuntary sterilization of all persons who suffered from diseases which were considered as hereditary, such as mental illness (schizophrenia and manic depression), retardation (“congenital feeble-mindedness”), physical deformity, epilepsy, blindness, deafness, and severe alcoholism, was carried out. About 400,000 Germans were sterilized under this law [20].
There were concerns about hereditarily healthy families adopting a policy of having only one or two children, while those with undesirable hereditary conditions were  reproducing unrestrainedly and their sick and asocial offspring were becoming a burden to the community. The main targets of the sterilization campaigns were patients in mental hospitals and other institutions. The common age group was between the ages of twenty and forty, and the numbers of males and females was about equal. However, majority of them were “Aryan” Germans.
In Germany and annexed territories Hereditary Health Courts were set up, each of which consisted of two physicians and one district judge. Doctors had an obligation to report all hereditary cases to these courts. Although  there were Appeals Courts, decisions were rarely reversed. Occasionally exemptions were provided to artists or other talented persons who had mental illnesses. In 1935 the “Sterilization Law” was followed by the Marriage Law which required proof that a marriage would not result in an offspring afflicted with a disabling hereditary disease.
The German Protestant Churches cooperated with the sterilization policy but the Roman Catholic Church, for doctrinal reasons, was opposed the sterilization program. Films and school education systems were drummed up to support of the policy [20].
In 1939, Hitler introduced the Aktion T-4 program, which allowed selected doctors and officials to carry out mercy killing-euthanasia-of those who the state deemed unworthy of living. This mercy killing was carried out by 50 volunteer physicians. Doctors at hospitals and psychiatric institutions throughout Germany identified and recommended candidates for such killings [21].
At initiation of the T-4 program, the doctors murdered 5000 congenitally deformed children with lethal injections and some were starved to death.
Later the project included killing of adults. The families were given death certificates with falsified cause of death [21].
Due to pressure from church groups and the public the T-4 program was ultimately halted by Hitler but by then in August 1941 about 70,000 people had been killed under the T-4 project. Although the T-4 project was halted, the killing did not stop. Physicians and nurses continued selective killing and covered up their actions [20]. The killing continued with the extermination in gas chambers of 6 million jews and ‘millions of political prisoners, Gypsies, the handicapped, those too ill to work, Jehovah's Witnesses, homosexuals, Afro-Europeans, and Soviet and Polish prisoners-of-war’ [21].
Several factors influenced the eugenics-based horrors of the Holocaust. These included social, political, military and economic factors. What really made the Holocaust possible was the ‘Nazis' total disregard for the rights and dignity of human beings’ [21].

Eugenics and Religion

Christianity and eugenics

“We all desire to improve the stocks of which our race consists. […] We know that many children born had better not exist, and I have been converted to a belief in euthanasia and to acceptance of the principle of sterilisation of those carrying unwholesome genes”. E.W. Barnes, Bishop of Birmingham [22].

Eugenics was born as a result of conflict between ‘scientific naturalism and its theological opponents’. Galton opposed dogmas of religion and he tried to ‘replace the Christian faith by a system of belief based on natural science’ [23]. Galton tried to overcome the conflict between eugenics and organized religion by introducing eugenics into the national conscience like a new religion. Eugenicist tried to empower individuals and society with promises of biological improvement of mankind and offered an alternate form of spirituality which did not rely on an almighty God. Eugenics was considered by some to be a ‘secular religion’ [23].
In the early 20th century when British Eugenics Society was in its infancy the Protestant clergy was well represented in the society but the Catholic clergy was conspicuously absent. Some of the well known protestant clergymen were Rev E. W. Barnes, William Inge (1860–1954), Charles D’Arcy and S.T. Percival all of whom advocated eugenics. In fact Inge, who was the then Dean of St Paul’s Cathedral, like Barnes believed that ‘there is nothing inconsistent with Christianity in imposing as well as enduring personal sacrifice where the highest welfare of the community is at stake’ [24]. Inge was a prolific author and he had a huge audience. He later gained an international reputation for being  a Christian proponent of eugenics.
Inge made a strong stand for negative eugenics which advocated prevention of multiplication of undesirable types by sterilization and birth control. He believed that negative eugenics was more important than positive eugenics i.e the encouragement of the better stocks to reproduce
their kind [24].
One of the most well know Anglican clergyman who was a radical eugenicist was Rev E.W. Barnes, the Bishop of Birmingham from 1924-1953. He along with other modernist tried hard to reconcile Anglicanism with the doctrine of evolution. Barnes spent his professional life as a mathematician and scientist at Cambridge from 1898–1919 and he was the Bishop of Birmingham from 1923–1953. From 1945 to 1953, he was a fervent supporter of negative eugenics and at the same time he was ‘the Church of England’s foremost champion of religious heterodoxy’ [25]. He fought hard to make beliefs of the Christian religion to ‘come to terms with science and scholarship’[25]. He argued that the viewpoint of eugenics and Anglicanism were complementary. He saw eugenics as a ‘means to fulfill God’s divine, evolutionary plan for humanity, drawing both on theories of modern science – particularly evolutionary biology – and Christianity to develop his own distinct ideology’ [25]. He supported pacifism, evolutionism, racism, sterilization, birth control and divorce, all viewpoints which are conventionally not supported by the Anglican Church.
Although the eugenics movement in Britain was greatly discredited and marginalized after the Second World War due to the true horrors of the ‘Nazi Rassenhygiene’,  Barnes began directly advocating the introduction of eugenic measures only after the Second World War although he had been involved with the eugenics movement for 30 years [25].
The Catholic clergy was conspicuously absent in the eugenic movement. In 1958, the Pope Pius XII (1876–1958) criticized the eugenic viewpoints. He called sterilization ‘a grave violation of moral law’. He said that sterilization cannot be justified even for preventing the transmission of heredity diseases. According to the Pope no human being had the right  under any pretext to permit sterilization because it was a violation of moral law and was against God’s divine plan [25].

Islam and eugenics

There is apparently no conflict between science and religion in Islamic faith [26]. However some genetic disorders occur frequently in Islamic/Arab countries in all socioeconomic groups of families[27]. Some of these disorders  which occur quite frequently include haemoglobinopathies, thalassaemias, enzymopathies, some inborn errors of metabolism, neurological disorders, muscular disorders and congenital defects.
The occurrence of these disorders is linked to consanguinity and recessive genetic disorders. Consanguinity is common in Islamic nations and first cousin marriages are common and second cousin marriage and other forms of inbreeding also occurs. Marriages among individuals with the same tribe are common. This inbreeding is responsible for the frequent occurrence of rare hereditary disorders [27]. Though most attribute consanguinity among muslims to cultural practices, it is, however, more likely due to religious islamic believes, since, in populations where muslims and hindus have lived in the same community for generations, consanguinity is never practised and is forbidden among those of other faiths.
Eugenics for the purpose of elimination of negative traits and hereditary diseases has not been practised among people of the muslim faith even though it has been known for hundreds of years that consanguinity is responsible for the transmission of many harmful hereditary disorders.
Abortions, all forms of artificial insemination by a donor or egg donation,  euthanasia and female sterilization are generally not allowed in Islam. Abortion and sterilization may be allowed under certain strict circumstance but not for the purposes of eugenics. Islam forbids celibacy, monasticism and castration. Muslims are prohibited from having abortions, as well as, practising infanticide and sterilization [28].

Eugenics in Hinduism

There are various estimates of  how long the Vedas and Hinduism may be have existed. Some estimate that the Vedas and Hinduism may have exited at least since 5000 BC (7000 years ago). Eugenics apparently is the basis of the  “Varna System”. Varna is a Sanskrit word which means type, order, colour or class. Varna refers to social classes in Brahmanical books which classified the society into four varnas:

• Brahmins: priests, scholars and teachers.
• Kshatriyas: rulers, warriors and administrators.
• Vaishyas: agriculturalists and merchants.
• Shudras: laborers and service providers.

Those who belong to one of the four varnas or classes are called savarna and they are known as forward castes. The Dalits and scheduled tribes who do not belong to any varna, are called avarna.
There are numerous verses in Vedas and ManuSmriti and even in the Bhagavad Gita which propagate eugenics. One of them from Manusmriti goes as follows,
“Only a servant woman can be the wife of the servant, twice-born men who are infatuated as to marry women of low caste quickly reduce their families, including descendants to the status of servants”
It can be inferred from this verse that Eugenics was/is a central facet of Hinduism. In the caste system eugenics was practiced which prevented the finer human strains from dilution and disappearance through indiscriminate mix marriages. Historically in India the best form of marriage was known as brahmanya marriage whose sole objective was the improvement of the progeny. The choice of mate rested with, not the parties to marriage, but with the elders and guardians. Marriages were a sacred duty where considerations of self and passion had no role. Marriages outside the the caste and race were undesirable and hence prohibited. Some of the marriages were arranged in infancy so that the progeny could be improved. Irrespective of the happiness or otherwise of these marriages, eugenically such marriages had merit.  [29].

Modern Eugenics

Spectacular breakthroughs in physics and chemistry occurred in the 20th century but the 21st century belongs the biological sciences where scientists are now able to decipher the genetic code of life. The days of ‘fusing, melting, soldering and forging’ have now been replaced by ‘splicing,
recombining, inserting, and stitching living material’ [30].
In the last couple of decades extensive scientific developments have taken place fields of DNA technology and genetic engineering. We have come a long way since the birth of the world’s first “test tube” baby in 1978.The technology involved in, in-vitro fertilization is now being used all over the world. Since in, in-vitro fertilization, the embryo is in an external  environment (laboratory), it makes it possible to do genetic manipulation to “correct” genetic disorders. Proponents of gene manipulation seek to eradicate defective genes from the human population in future [31]. This can rightly be described as resurrection of eugenics.
The three dimensional structure of the DNA was discovered by Watson and Crick in 1953. This made it possible to study the mechanism of how DNA is able to replicate itself during the division of cell. About 20 years later restriction enzymes were discovered which can chemically cut DNA molecules at specific places. This opened up new fields of recombinant DNA technology, gene “cloning,” and genetic engineering [32]. The use of such enzymes make it possible to isolate particular genes from human chromosomes which allows for gene cloning [31].
The CRISPR-Cas9 (gene-editing technique discovered by scientists at MIT) technology is now available which allows scientists to design proteins that unzip and replace chunks of DNA which makes  gene editing quick and cheap.
The ability to select good genes, eliminate bad genes, and increasing the reproduction of fit individuals will pay the way for positive eugenics. We can now for the first time in history, engineer life itself, reprogram the genetic codes of living entities to suit our own needs for the propagation of positive eugenics. It is likely that genetic engineering could alter genes in fetuses to correct deadly diseases and disorders, as well as have some effect on modification of mood, behavior, intelligence and physical traits.
We used to believe that our fate was determined by God or as some would say by our stars but now we know that it (fate) is in our genes. Knowing that our fate is in the genes would make it possible to manipulate our fate. Many are now questioning whether we should be playing God and should we be engineering future generations, because such pursuit would have ethical implications. There are some who fear that genetic engineering of humans may reduce human genetic diversity which may in turn create a ‘biological monoculture’ which can increase our susceptibility to diseases and even lead to the extinction of our species [33].
Despite worldwide resistance to experimentation of gene editing in human embryos, a team at Sun Yat-sen University in Guangzhou, China, led by  Junjiu Huang confirmed they had engineered human embryos to modify the gene responsible for the fatal blood disorder thalassaemia [34] . Though the team, attempted to head off fears of eugenics by claiming the embryos were ‘non-viable’ and could never had become babies, the prestigious science journals Nature and Science refused to publish the study on ethical grounds. The research was then published in journal Protein and Cell. The critics in the west labeled China as ‘Wild West’ of genetic research and claimed that this was the step towards designer children and called for a worldwide ban on the practice [35].

Conclusion

Historically there has been selective breeding to improve the qualities of the human species or a human population by the Hindus as far back as 7,000 years ago. However it was Francis Galton who first coined the term eugenics in 1800’s and he was the pioneer who developed the subject of eugenics. He relentlessly pursued the science of improving the inherited stock, not only by judicious matings, but by all other influences. From London the study and practice of eugenics spread to USA. Although the British practiced positive eugenics, the American eugenics movement promoted elimination of negative traits. This led to a push for legislation which resulted in mass sterilization of the uneducated, poor and minority population.
Despite the lack of scientific proof that many of those undesirable traits, which were the target of eugenics, have a genetic basis, eugenics spread to Nazi Germany. In Germany it led to the horrors of the ‘Nazi Rassenhygiene’,which saw the elimination of a huge section of society in and around Germany.
Beside the Anglican church which was actively involved in eugenics in Britain, most other religious bodies were against the practice of eugenics.
Over the last few decades extensive scientific developments have taken place in the fields of DNA technology and genetic engineering. We will certainly be witnessing a resurgence of interest in modern eugenics in the future. What the future hold for us is uncertain but there is a good likelihood that humans will be playing God in future, now that human traits can be manipulated in the laboratory.


   

References

1. https://en.oxforddictionaries.com/definition/eugenics.
2. https://www.merriam-webster.com/dictionary/eugenics.
3. www.dictionary.com/browse/eugenics.
4. Galton F. Inquiries into human faculty and its development. London: J M Dent and Sons, 1943:17.
5. Galton DJ, Galton CJ. Francis Galton: and eugenics today. Journal of Medical Ethics 1998;24:99-105.
6. David J Galton. Greek theories on eugenics. Journal of Medical Ethics 1998;24:263-267.
7. Norrgard, K. (2008) Human testing, the eugenics movement, and IRBs. Nature Education 1(1):170.
8. Galton Institute. Later life. The eugenic vision at http://www.galtoninstitute.org.uk/sir-francis-galton/eugenics-and-final-years/. Accessed on 22/11/17.
9. The Eugenics Review, 1909, I (Apr.), inside front cover.
10. Camery, Luke. "The Black Stork; Eugenics and Infanticide in twentieth century America" at https://docs.google.com/file/d/0B9BESb-X9dvza00wRmFzZjRkUTA/edit. Accessed on 18/11/17
11. Lombardo, Paul. "Eugenic Sterilization Laws." Eugenics Archived. N.p., n.d. Web. 07 May 2014. <http://www.eugenicsarchive.org/html/eugenics/essay8text.html>.
12. Black, Edwin. "The Horrifying American Roots of Nazi Eugenics." History News Network. N.p., Sept. 2003. Web. 07 May 2014. <http://hnn.us/article/1796>.
13. Buck vs. Bell Trial at http://www.eugenicsarchive.org/html/eugenics/static/themes/39.html. Accessed on 19/11/17.
14. Moser HW. Genetic causes of mental retardation. Ann N Y Acad Sci. 2004 Dec;1038:44-8.
15. Lichtenstein, P., Yip, B. H., Björk, C., Pawitan, Y., Cannon, T. D., Sullivan, P. F., & Hultman, C. M. (2009). Common genetic influences for schizophrenia and bipolar disorder: A population-based study of 2 million nuclear families. Lancet, 2009; 373(9659), 10.1016/S0140–6736(09)60072–6. 
16. Dimitri M Kullmann. Genetics of epilepsy. J Neurol Neurosurg Psychiatry 2002;73(Suppl II):ii 32–ii 35.
17. Fontaine N, Viding E. Genetics of personality disorders. Psychiatry 2008; 7(3): 137-141.
18. Philip Hunter. The psycho gene. EMBO Rep. 2010 Sep; 11(9): 667–669.
19. Howard J. Edenberg. The Genetics of Alcohol Metabolism: Role of Alcohol Dehydrogenase and Aldehyde Dehydrogenase Variants. Alcohol Res Health. 2007; 30(1): 5–13.
20. Holocaust Teacher Resource Centre at http://www.holocaust-trc.org/handicapped/.
21. Chapter 5 The Nazi Eugenics Programs at https://highschoolbioethics.georgetown.edu/units/cases/unit4_5.html. Accessed on 21/11/17.
22. Ernest W. Barnes, ‘Reply to Fisher RE: Artificial Insemination,’ (20 February 1945), The Papers of E.W. Barnes, Special Collections Library, University of Birmingham, 9/21/10 (Hereafter: EWB X/YY/ZZ).
23. Merricks, P (2014) Should such a faith offend? Bishop Barnes and the British eugenics movement, c. 1924-1953 PhD, Oxford Brookes University.
24.  Inge, ‘Some Moral Aspects of Eugenics’, The Eugenics Review, 1:1 (April 1909), p. 34.
25. Patrick T. Merricks (2012): ‘God and the Gene’: E.W. Barnes on Eugenics and Religion, Politics, Religion & Ideology, 13:3, 353-374.
26. Zahedi F, Larijani B. Medical genetic ethics, Islamic views and considerations in Iran. Daru. 2006;14(suppl 1):48–55.
27. Mohsen A.F. El-Hazmi, Ethics of genetic counseling —basic concepts and relevance to Islamic communities. Ann Saudi Med. 2004; 24(2): 84-92.
28. Jamal Zarabozo. Is family planning allowed in Islam? At http://www.islamswomen.com/marriage/is_family_planning_allowed_in_islam.php. Accessed on 26/11/17.
29. Roy TN. Hindu eugenics. Journal of Heredity, Volume 18, Issue 2, 1 February 1927, Pages 67–72.
30. Jeremy Rifkin. Genetic Commerce and the Dawn of a New Era at http://90.146.8.18/En/archiv_files/19991/E1999_047.pdf. Accessed on 1/12/17.
31. Ewing CM. Tailored genes: IVF, genetic engineering, and eugenics. Reprod Genet Eng. 1988;1(1):31-40. 
32. Emtage, J. S. 1985. DNA makes protein makes money. Nature 317:185-186.
33. Russell Powell. The Evolutionary Biological Implications of Human Genetic Engineering. Journal of Medicine and Philosophy 37 (1):22 (2010).
34. Liang, P., Xu, Y., Zhang, X., Ding, C., Huang, R., Zhang, Z., … Huang, J. (2015). CRISPR/Cas9-mediated gene editing in human tripronuclear zygotes. Protein & Cell, 6(5), 363–372. http://doi.org/10.1007/s13238-015-0153-5.
35. Sarah Knapton. China shocks world by genetically engineering human embryos at http://www.telegraph.co.uk/news/science/11558305/China-shocks-world-by-genetically-engineering-human-embryos.html. Accessed on 1/12/17.