Originally published on the Hospital of Saint Raphael website, now no longer showing.
Arastoo Vossough, M.D., Robert J. Nardino, M.D.
Hospital of Saint Raphael, 1450 Chapel Street, New Haven, Connecticut
Coccygodynia is commonly caused by trauma and resultant contusion, fracture, or dislocation of the coccygeal vertebrae, but can be due to subclinical hypermobility, posterior dislocation in the sitting position, or excess osteochondral tissue around the coccyx and can even occur postpartum. Arachnoid cysts, disc disease, vertebral anomalies, avascular necrosis, anterior angulation of the coccyx and tumors are other causes of coccygodynia. Intractable coccygodynia can be a very debilitating disorder. Coccygectomy is often used as a last resort but its success varies from 20% to 90%.
A 59-year old retired army major presented with 17 months of moderate to severe pain in the coccygeal area. The pain had started gradually during a four-day period, was constant with intermittent exa cerbations and worse on sitting. There was no history of antecedent trauma. He had undergone extensive investigation of the cause of this pain. Lateral decubitus and sitting radiography of the coccyx had not shown any fracture, hypermobility, luxation or any other abnormality of the coccyx. CT scan, myelography, discography, electromyography, and manometry, and sigmoidoscopy had all been normal.
Acetaminophen, codeine, ibuprofen, antidepressants, physical therapy, electrogalvanic stimulation and acupuncture reflex therapy had no or minimal effect on the pain. Local anesthetic and steroid injections of the sacrococcygeal joint had provided satisfactory but only short-term relief. The patient had refused to undergo coccygectomy without identifying the cause. He had devised a torus shaped pillow that he carried with himself everywhere in order to be able to sit and was suffering from considerable social and physical dysfunction.
On physical exam the coccygeal area was exquisitely tender to deep pressure on the coccyx and to digital rectal exam, although there was no redness, warmth or swelling. The rest of the physical exam was normal. The patient was found to have borderline high serum uric acid levels. Twenty-four hour urinary uric acid levels were 50.5 mmol/day initially and 48.7 mmol/day on a purine-free diet. The coccygeal joint area was aspirated and intracellular negatively birefringent crystals of monosodium urate were identified. No evidence of a tophus was found. The patient was given a full course of oral colchicine and the pain subsided completely in two days. He was then started on allopuriol and was pain-free at 10 months follow-up.
Gouty arthritis is an acute or chronic inflammatory process usually seen in synovial joints. This is the first report of gout as an etiology of coccygodynia. It is suggested that gout be considered as an easily treatable cause in the differential diagnosis of coccygodynia, especially in cases without obvious anatomical abnormalities.