tail piece

1386

Tail pieceThe tail, a conspicuous feature of so many

mammals, has in man shrunk to a vestigial andinvisible organ of between 3 and 5 bones. Despite itssize and location, the human tail has been granted animaginative title (coccyx) by the anonymousanatomist who likened it to the cuckoo’s beak. Theterm coccygodynia, often contracted to coccydynia,was introduced by Simpson in 18591 to describe thesymptom of pain in this region, a complaint longgranted the status of a "heartsink condition" bypatient and doctor alike. By 1896, Bremer2 held theview, so often adopted by doctors when faced with anintractable and inexplicable symptom, that it was amanifestation of neurosis or even hysteria, especiallysince coccydynia is five times as common in women asin men. More recently coccydynia has been regardedas a symptom of depression.3 The aetiology in manycases remains obscure, but trauma, avascular

neurosis, and various rare tumours (eg, chondroma,5 5

giant cell tumour,6 6 intradural schwannoma,6 6

perineural cyst,’ and introsseous lipoma8) havesometimes been implicated. The glomus body, whichis almost certainly a normal structure lying anterior tothe coccyx,9 is widely believed to be a pathologicallesion.1o,11 Proctologists have taken an interest in

coccydynia for many years, and the condition has beenassociated with several anal disorders.5 Where suchabnomalities could not be found, a disturbance of theligaments and muscles attached to the coccyx wasproposed.12 Another suggesion was that the painmight be referred from an invertebral disc prolapse orother abnormality in the lumbar spine.13

Clinicians have evolved numerous therapies forcoccydynia, many of doubtful value. At last, 132 yearsafter the first description of coccydynia, and 265 yearsafter the first coccygectomy, a clinical trial has beenmounted in Leicester 15 whose results offer us a

rational treatment protocol for the condition. Wrayet al first conducted a pilot study of 50 patientswith coccydynia; these patients underwent a

thorough investigation, including rectal examination,radiography, bone scan, computed tomography, andfull psychiatric assessment. A hierarchy of treatmentswas then instigated-first 2 weeks of ultrasound and 2weeks of shortwave diathermy (16% success). 42patients proceeded to the next stage-local injection ofmethylprednisolone and bupivicaine, which was

repeated, if necessary, 4 weeks later (38% success).The remaining 28 patients were treated with

manipulation under anaesthesia, in which the surgeongrasped the coccyx by placing his index finger in thepatient’s rectum and his thumb behind and thenrepeatedly flexed and extended the bones for a minute.After 6 weeks all but 8 were cured, and they proceededto coccygectomy. The entire cohort was followed forat least 12 months. Of the 50 patients, 3 were thoughtto have abnormal personality traits; 2 came to surgery,with 1 cure. 48% of the pilot study patients had

computed tomographic abnormalities of the lumbarspine, which were felt to be irrelevant in view of thesuccess of local treatments to the coccyx and the

generally high frequency of symptomlessabnormalities in the lumbar spine.Wray et al then proceeded to a randomised trial.

They compared the efficacy of injection alone againstmanipulation under anaesthesia and injection. 120patients were recruited. The aetiology was a fall in 30and childbirth in 14; 15 had had repetitive strain ontheir bottoms (eg, from a rowing machine or

bicycling); and 6 dated their symptoms from a surgicalprocedure (3 in the lithotomy position). 60%

responded to injection alone, and 85% to

manipulation and injection. On completion of thetrial, 23 patients came to coccygectomy and all but 2had a good result.

Thus, the Leicester workers have swept away manyof the ill-conceived notions surrounding this

complaint, and have shown that 80% of patients withcoccydynia can be treated conservatively. The curiousperception of many surgeons that coccygectomy is amad or bad operation is belied both by this and byother reports.5,16-21 Patients with coccydynia deservemore than a look of incredulity from their doctor andthe offer of a ring cushion.

1. Simpson JY. Coccygodynia and diseases and deformities of the coccyx.Med Times Gazette 1859; 861: 1.

2. Bremer L. The knife for coccygodynia. Med Rec (NY) 1896; 1: 154-55.3. Maroy B. Spontaneous and evoked coccygeal pain in depression.

Dis Colon Rectum 1988; 31: 210-15.

4. Lourie J, Young S. Avascular necrosis of the coccyx: a cause for

coccydynia? Case report and histological findings in sixteen patients.Br J Clin Pract 1985; 39: 247-48.

5. Hodge J. Clinical management of coccydynia. Med Trial Tech 1979; 25:277-84.

6. Kinnett JG, Root L. An obscure cause of coccygodynia. J Bone Jt Surg1979; 61-A: 299.

7. Ziegler DK, Batnitzky S. Coccygodynia caused by perineural cyst.Neurology 1984; 34: 829-30.

8. Hanelin LG, Sclamberg EL, Bardsley JL. Intraosseous lipoma of thecoccyx. Radiology 1975; 114: 343-44.

9. Bell RS, Goodman SB, Fornasier VL. Coccygeal glomus tumors: a caseof mistaken identity? J Bone Jt Surg 1982; 64-A: 595-97.

10. Ho K-L, Pak MSY. Glomus tumor of the coccygeal region. Case report.J Bone Jt Surg 1980; 62-A: 141-42.

11. Duncan L, Halverson J, DeShryver-Kecskemeti K. Glomus tumor of thecoccyx: a curable cause of coccygodynia. Arch Pathol Lab Med 1991;115: 78-80.

12. Thiele GH. Coccygodynia. Dis Colon Rectum 1963; 6: 422-36.13. Dittrich RJ. Coccygodynia as referred pain. J Bone Jt Surg 1951; 33-A:

715-18.

14. Petit JL. A treatise of the diseases of the bones, translated from theFrench. London: T Woodward, 1726.

15. Wray CC, Easom S, Hoskinson J. Coccydynia: aetiology and treatment.J Bone Jt Surg 1991; 73-B: 335-38.

16. Key JA. Operative treatment of coccygodynia. J Bone Jt Surg 1937; 19:759-64.

17. Howarth B. The painful coccyx. Clin Orthop Rel Res 1959; 14: 145-61.18. Borgia CA. Coccydynia: its diagnosis and treatment. Milit Med 1964;

129: 335-38.

19. Porter KM, Khan MAA, Piggott H. Coccydynia: a retrospective review.J Bone Jt Surg 1981; 63-B: 635-36.

20. Wray AR, Templeton J. Coccygectomy: a review of 37 cases. Ulster MedJ 1982; 51: 121-24.

21. Postacchini F, Massobrio M. Idiopathic coccygodynia. J Bone Jt Surg1983; 65-A: 1116-24.