Bernard is a keen sportsman who unfortunately suffered with severe pain around his right ankle for six long years until the elusive diagnosis was made and an instant cure provided. He was 34 years old when he first presented with the pain, which developed insidiously.
He consulted a rheumatologist who said that he had post-traumatic arthritis and that an X-ray that reported ‘some spurring on the dorsal surface of the neck and body of the right talus’ was of little significance (Figure 7.2).
Fig. 7.2 Plain X-ray of Bernard’s foot. Note the osteophytic reaction on the anteromedial aspect of the talus with radiolucent areas
Bernard first consulted me about 12 months after his problem started, when the pain became very severe, causing him sleepless nights unless he took non-steroidal anti-inflammatory drugs (NSAIDs). He described the pain as feeling ‘as though there was a nerve on edge’ but said the aspirin was very effective for pain relief. On examination of his right ankle there was acute localised tenderness on the anteromedial aspect of his ankle with some diffuse area of soft tissue swelling. The ankle joint was stable, and all movements and gait were normal. I referred him to an orthopaedic surgeon who was an expert on ankle disorders.
The surgeon found a large area of discoloured irregular looking synovitis with bone erosions on both the talus and the anterior tibia. He said the diagnosis was uncertain and performed localised synovectomy, which was reported as ‘non-specific chronic synovitis’.
Bernard’s pain continued relentlessly. The surgeon felt Bernard should be fine, but further visits to his rheumatologist did not help. The latter performed several tests including full blood examination (FBE), ESR, rheumatoid arthritis factor, uric acid, tissue typing and plain X-rays, all of which were reported as normal. Bernard was told that he had ‘a low-grade inflammatory joint disease, most likely of rheumatoid variation’ and that he would have to learn to live with it with the help of the effective NSAIDs. However, he battled on bravely even with the label of ‘neurotic’, which he himself was beginning to believe. Acupuncture and various other remedies were ineffective.
When I met Bernard socially five years later, I was distressed to discover that in addition to his painful ankle he had a severe duodenal ulcer that was responsible for melaenas. He was now on ranitidine (Zantac) and naproxen (Naprosyn). He said that the ankle pain was worse than ever, especially at night. It was intense first thing in the morning when he put his foot to the floor. He then hobbled around for 15 minutes, but it did not bother him much during the day when he was occupied and busy.
‘Light switch’ and the solution
Something suddenly clicked in the sluggish grey matter. Could it be? I rang another orthopaedic surgeon and, yes, he thought an osteoid osteoma was a definite possibility. We organised a bone scan that showed a hot spot in the neck of the talus ‘suggestive of an osteoid osteoma’.
At surgery bone chiselling revealed the seemingly innocent little tumour that caused so much pain—the osteoma with its cherry red soft core about 8 mm in diameter. It was removed and the defect packed with bone wax.
Bernard has lived and slept happily ever after. Well almost! The epigastric pain of his old NSAID-induced peptic ulcer still reminds him of six years of relative hell!
DISCUSSION AND LESSONS LEARNED
Osteoid osteomas are nasty little tumours that test the diagnostic acumen of the practitioner mainly because they are rare. As a rule they affect older children and adolescents, and males are affected twice as often as females. The pain is not relieved by rest but classically by aspirin. Any bone (except those of the skull) can be affected but the tibia and the femur are the main targets.
Patients complaining of chronic pain can be readily labelled as functional. Somehow these patients believe they harbour a tumour and failure to diagnose the tumour makes us look professionally incompetent. As Bailey (1960) puts it: ‘In mild or early cases the pain occasioned by this condition is often attributed to a neurosis’.
Careful note should be taken of any abnormal X-ray signs, especially with a persistent clinical problem. The radiological changes (sclerotic lesion with radiolucent centre) were present but ignored.
Some degree of surgical intervention tends to make us complacent that we have a definitive answer to the problem.
Long-term NSAIDs are a hazard as well illustrated with this patient. Despite withdrawal over 12 months the patient still suffers from peptic ulceration.
The next time around we hope we will all pick the osteoid osteoma. Or will we? As our surgeon said: ‘Always think of an osteoid osteoma in a young lad with unusual pain in a leg (especially pain that responds nicely to aspirin or paracetamol)’.