Coccydynia-Treatment

                           Coccydynia-Treatment

                                                      Dr KS Dhillon

Anatomy of the coccyx

The coccyx, also known as the tailbone is the terminal end of the spine, just distal to the sacrum. It is about one inch in length and is curved like a hawk’s beak.The human coccyx is considered as a vestigial remnant of a tail. It is composed of 3-5 coccygeal vertebrae. In 80% of individuals, the coccyx is made up of 4 coccygeal vertebrae. The individual bones fuse together to form a single coccygeal bone throughout adulthood. In some individuals, however, the bones only partially fuse, resulting in two separate coccygeal bones.

Anteriorly the coccyx is concave and posteriorly it is convex in shape. The coccyx has an apex, base, anterior surface, posterior surface and two lateral surfaces. The base located proximally contains a facet for articulation with the sacrum. The apex is situated distally at the inferior tip of the coccyx. The lateral surfaces of the coccyx are marked by a small transverse processes, which project from 1st coccygeal vertebra.

The 1st coccygeal vertebra has two small articular processes called coccygeal cornua which articulates with the sacral cornua to form the  sacrococcygeal symphysis. It is a fibrocartilaginous joint which allows limited flexion and extension movements. The intercoccygeal joints also
contain fibrocartilaginous discs.

There are four configurations of the coccyx which were described by Postacchini and Massobrio [1]

Type I: Coccyx is slightly curved forward, with the apex directed downward and caudally.
Type II: Forward curvature is more marked, and the apex extends straight forward.
Type III: Coccyx angulates more sharply forward.
 Type IV: Coccyx is subluxated at sacrococcygeal joint or at intercoccygeal joint.


The sacrococcygeal symphysis is supported by five ligaments:

• Anterior sacrococcygeal ligament which is a continuation of the anterior longitudinal ligament of the spine, and it connects the anterior aspects of the vertebral bodies.
• Deep posterior sacrococcygeal ligament which connects the posterior surface of the 5th sacral body to the posterior surface of the coccyx.
• Superficial posterior sacrococcygeal ligament which attaches the median sacral crest to the dorsal surface of the coccyx.
• Lateral sacrococcygeal ligaments which run from the lateral aspect of the sacrum to the transverse processes of 1st coccygeal vertebra.
• Intra articular ligaments which stretch from the cornua of the sacrum to the cornua of the coccyx. 

The coccyx has an attachment for the gluteus maximus muscle which is a major extensor of the thigh at the hip. The levator ani muscle which consists of the coccygeus, iliococcygeus, and pubococcygeus, also arise from the coccyx. This muscle group supports the pelvic floor (preventing inferior sagging of the intrapelvic contents) and also plays a role in maintaining fecal continence. A midline component of the muscle is the anococcygeal raphe which supports the position of the anus. The coccyx via the anococcygeal ligament helps to support the anus by holding the external anal sphincter in place.

Function of the coccyx

The coccyx and the ischial tuberosities forms a tripod on which an individual sits.The coccyx bears more weight when the seated person is leaning backward and less weight when a person leans forward.

Besides the weight bearing function it also provides support for the pelvic floor and the anus as well as plays a role maintaining fecal continence. 

Coccydynia

Coccydynia (also referred to as coccygodynia, coccalgia, coccygalgia, or coccygeal pain) is a painful syndrome affecting the coccygeal region. It is a rare condition. The patient presents with pain in the coccygeal region which occurs while sitting on hard surfaces and sometimes on getting up from sitting position.

Epidemiology

Frequency

Coccydynia is the cause of back pain in less than 1% of all back pain conditions [2, 3, 4]. It is five times more common in women as compared to men [5]. The mean age of onset is usually around 40 years of age [5].

Etiology of Coccydynia

The most common cause of coccydynia is external or internal trauma. External trauma usually results from a fall on the buttocks or a fall backwards which leads to a bruised, dislocated, or broken coccyx [6]. The  coccyx may also be injured during childbirth especially with instrumented and difficult deliveries. Prolonged sitting on hard narrow and uncomfortable surfaces can lead to minor trauma to the coccyx leading to coccydynia [2]. Non-traumatic coccydynia can result from degenerative joint or disc disease, hypermobility of the coccyx, hypomobility of the sacrococcygeal joint, infections,and malignancies. The pain in the coccygeal region can also be referred pain from other sites. Less commonly coccydynia can be associated with non-organic causes, such as somatization disorder and other psychological disorders [7].

The configuration of the coccyx can predispose a patient to coccydynia and influence the type of pain the patient has. Types II, III, and IV are usually  more painful than type I [1]. Obesity can also a predisposing factor for coccydynia.

Clinical presentation and diagnosis

Most patients present with a history of a fall or an antecedent childbirth. The incidence of posttraumatic coccydynia is about 69.2% [8]. Some patients will present with no preceding incidence of trauma and the onset of pain can be insidious.

Patients usually present with tailbone pain which is worse on prolonged sitting, leaning back while sitting, on getting up from sitting and sometimes on prolonged standing. Sexual intercourse and defecation may also be associated with tailbone pain in some patients.

Physical examination usually reveals tenderness over the coccyx. A rectal examination allows manipulation of the coccyx and it will elicit pain and may reveal hypermobility or hypomobility of the sacrococcygeal joint.

X rays of the coccyx can reveal fractures, subluxations and dislocations of the coccyx. A comparison of lateral radiographs which are taken in the standing and in the most painful sitting position can reveal posterior subluxation of the coccyx and hypermobility of the coccyx [8]. Further evaluations can be carried out using CT scan images. When infection, tumours or other sources of pain are sought, an MRI can be useful.

Treatment of coccydynia

Non-surgical treatment

Non-surgical management remains the gold standard treatment for coccydynia. In many patients the pain resolves without treatment and conservative treatment is usually successful in 90% of cases [3,9,10]. Wedge-shaped cushions (coccygeal cushions) can be used to relieve pressure on the coccyx when  the patient is seated and these are usually available over the counter. Circular cushions (donut cushions) can increase pressure on the coccyx and are not suitable for treatment of coccydynia. Sitting bent forward helps to take pressure off the coccyx and its helps reduce the pain. Application of heat and cold sometimes helps too. Nonsteroidal antiinflammatory drugs (NSAIDs) are most commonly given for pain relief. Opioids are generally not prescribed for pain relief.

Maigne and Chattelier [11] studied the usefulness of levator ani massage, levator ani stretching, and sacrococcygeal joint mobilization in the treatment of coccydynia. They found that at 6-month the success rates for message were 29.2%, for stretching 32% and for joint mobilization 16%. The overall success rate with these conservative approaches was 25.7%.

Local injections of steroids with long acting anesthetics have been used for treatment of coccydynia where conservative treatment has failed. Wray et al [12] recommended a mixture of 40 mg methylprednisolone and 10 ml 0.25% bupivacaine. In some patients where symptoms persisted a third injection was performed in conjunction with coccygeal manipulation under general anesthetic. They reported a success rates of 59% with injections alone and 85% for the injections with manipulation. Twenty one percent patients receiving injections and 28% of those undergoing injections with concurrent manipulation developed recurrence of symptoms.

Although injections into the pericoccygeal tissues have been used in the treatment of coccydynia, there appears to be no clear consensus in the literature regarding the exact site of injection.
Plancarte et al [13] were the first to describe the use of radiofrequency to block the ganglion impar for pericoccygeal pain due to carcinoma. Others have used the same technique to relieve pain in patients with severe coccydynia [14]. Evidence-based literature supporting the effectiveness of these interventional procedures remains lacking.

The published literature on the use of various modes of treatment for coccydynia described above consists of case series which is especially vulnerable to selection bias. Unfortunately there are no cohort studies comparing different interventions and their outcomes.

Surgical treatment

Surgery for the treatment of coccydynia is used only as a last resort when all other treatment options have not been successful. The commonly used surgical procedure used for the treatment of chronic coccydynia not responding to other forms of treatment is coccygectomy. It involves surgical removal of the coccyx just proximal to the sacrococcygeal junction. There is scarcity of literature to support the use of this surgical procedure. As with other modes of treatment of coccydynia most of the available literature consists of case reports and retrospective case series with no cohort studies. The available literature suggests that a coccygectomy may provide relief in some subset of patients who have failed all other forms of treatment [8,10,12,15].

Infection is the most serious complication of coccygectomy because of  proximity of the coccyx to the rectum and anal canal. Rates as high as 16.6% [16] and 14.75% [17] have been reported in literature. Partial skin necrosis and superficial wound infection causing delay in wound healing has been reported in about 50% of the patients [1]. Besides the high complication rates, the procedure can be associated with failure to achieve pain relief. Therefore, ‘based on current available information, this procedure generally is not recommended’[18].

Conclusion

The etiology of the coccydynia can be complex and may often be multifactorial. It is a relatively rare condition with no universally accepted treatment protocol. The symptoms are often mild and the condition can sometimes be self limiting. Though most patients respond to conservative treatment, some may require more aggressive treatment.
A multidisciplinary approach using physical therapy, workplace adaptations, medications (NSAIDs), injections and psychotherapy where necessary, will provide the best opportunity for success in the treatment of these patients. Surgical coccygectomy is generally not recommended for the treatment of patients with coccydynia. More research is needed to establish which is the best mode of treatment of patients with coccydynia. Randomized control trials to study the outcome of treatment of patients with coccydynia are needed.

References

1. Postacchini F, Massobrio M. Idiopathic coccygodynia. Analysis of fifty-one operative cases and a radiographic study of the normal coccyx. J Bone Joint Surg Am. 1983 Oct. 65(8):1116-24.
2. Pennekamp PH, Kraft CN, Stütz A, Wallny T, Schmitt O, Diedrich O. Coccygectomy for coccygodynia: does pathogenesis matter?. J Trauma. 2005 Dec. 59(6):1414­9. 
3.  Thiele GH. Coccygodynia: Cause and treatment. Dis Colon Rectum. 1963 Nov­Dec. 6:422­-36.
4. Peyton FW. Coccygodynia in women. Indiana Med. 1988 Aug. 81(8):697­8. 
5. Fogel GR, Cunningham PY 3rd, Esses SI. Coccygodynia: evaluation and management. J Am Acad Orthop Surg. 2004 Jan­-Feb. 12(1):49­54.
6. Schapiro S. Low back and rectal pain from an orthopedic and proctologic viewpoint; with a review of 180 cases. Am J Surg. 1950 Jan;79(1):117-128.
7. Nathan ST, Fisher BE, Roberts CS. Coccydynia: a review of pathoanatomy, aetiology, treatment and outcome. J Bone Joint Surg Br. 2010 Dec;92(12):1622-1627.
8. Maigne JY, Doursounian L, Chatellier G. Causes and mechanisms of common coccydynia: role of body mass index and coccygeal trauma. Spine (Phila Pa 1976). 2000 Dec 1. 25(23):3072­9.
9. Capar B, Akpinar N, Kutluay E, Müjde S, Turan A. Coccygectomy in patients with coccydynia [in Turkish] Acta Orthop Traumatol Turc. 2007 Aug-Oct;41(4):277–280. 
10. Trollegaard AM, Aarby NS, Hellberg S. Coccygectomy: an effective treatment option for chronic coccydynia: retrospective results in 41 consecutive patients. J Bone Joint Surg Br. 2010 Feb;92(2):242–245. 
11. Maigne J, Chattelier G. Comparison of three manual coccydynia treatments: a pilot study. Spine. 2001;26:E479–84.
12. Wray C, Easom S, Hoskinson J. Coccydynia: aetiology and treatment. J Bone Joint Surg. 1991;73:335–8.
13. Plancarte R, Amescua C, Patt RB, Allende S. Presacral blockade of the ganglion of Walther (ganglion impar) Anesthesiology. 1990; 73(3A):A751.
14. Toshniwal GR, Dureja GP, Prashanth SM. Transsacroccygeal approach to ganglion impar block for management of chronic perineal pain: a prospective observational study. Pain Physician 2007;10:661–6.
15. Perkins R, Schofferman J, Reynolds J. Coccygectomy for severe refractory sacrococcygeal joint pain. J Spinal Disord Tech. 2003 Feb;16(1):100–103.
16. Bayne O, Bateman JE, Cameron HU. The influence of etiology on the results of coccygectomy. Clin Orthop 1984;190:266–72.
17. Doursounian L, Maigne JY, Faure F, Chatellier G. Coccygectomy for instability of the coccyx. Int Orthop 2004;28:176–9.
18. Lirette LS, Chaiban G, Tolba R, Eissa H. Coccydynia: an overview of the anatomy, etiology, and treatment of coccyx pain. Ochsner J. 2014;14(1):84-7.