Friday, 29 December 2017

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.
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  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.
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  8. Palmer AK. Triangular fibrocartilage complex lesions: A classification. J Hand Surg [Am]. 1989;14:594-606.
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  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.
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  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.
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  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.
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  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. 

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