Forty-seven patients who had monostotic enchondroma were treated at our clinic between August 1986 and December 1992. Five patients (four men and one woman), who were twenty-six to forty-two years old, had a lesion in the distal phalanx. Radiographs showed a thin and expanded cortex of the distal phalanx with the central portion occasionally containing small calcified specks. Two of the five patients had a severe deformity of the fingertip when they were seen by us. One had been aware of the deformity for fifteen years and the other, for twelve years. They reported a history of pain with minor trauma but had not sought medical treatment. One patient was managed with a disarticulation at the distal interphalangeal joint. The other patient, who had marked clubbing of the finger, was managed with curettage of the lesion and insertion of an autogenous bone graft through an incision that required longitudinal splitting of the nail.
The other three patients, two men and one woman, who were twenty-six, thirty, and thirty-seven years old, had sustained a pathological fracture after a minor traumatic episode and sought medical care within a few days after the onset of symptoms. The fractures united after three weeks of treatment with a splint. The tumors were treated with curettage through a palmar longitudinal incision and insertion of an autogenous iliac bone graft three, twenty-four, and thirteen months after the onset of symptoms. One patient returned to work after twenty-eight days and the other two, after twenty-one days. They regained normal function by three, four, and three months postoperatively. The latest follow-up was ninety, eighty-two, and forty months after the operation.
Operative Technique
Curettage and bone-grafting were performed with the use of regional anesthesia and a tourniquet. The incision began on the midline of the pulp ten millimeters proximal to the fingertip and extended longitudinally to just distal to the distal finger crease. We took care not to touch or cross the distal finger crease. The pulp was dissected sharply down to the bone, and the phalangeal cortex was exposed by subperiosteal elevation to minimize damage to the fascial septa of the pulp. A window was cut in the cortex, and cancellous bone from the iliac crest was packed into the defect after curettage. Subcutaneous sutures were not used, and the skin was closed with interrupted sutures. A sterile compressive dressing was applied and kept in place until the pain and swelling had subsided.
The diagnosis was confirmed histologically. During the follow-up period, none of the patients reported pain and all maintained good function of the hand. There had been no recurrences at the time of the latest follow-up.
Enchondroma of a long bone of the hand is a common tumor, although the distal phalanx is an uncommon location. The prognosis after curettage and insertion of autogenous bone graft7,11 or allograft2,5 is excellent, and satisfactory results have been reported with curettage alone4,11-13. Takigawa reported that 4 per cent (three) of seventy-five monostotic enchondromas and 14 per cent (thirty) of 213 polyostotic enchondromas were in the distal phalanx. Noble and Lamb found that 13 per cent (six) of forty-six enchondromas (in thirty-five patients who had a monostotic lesion and four who had polyostotic lesions) were in the distal phalanx. To our knowledge, the natural history of enchondroma of the distal phalanx has not been described. Of our five patients, two did not seek medical attention until the deformity became severe, although the histories suggested several episodes of pathological fracture secondary to minor trauma. It is possible that these patients had slight pain of short duration since the nail acts as a protective splint.
An enchondroma of the distal phalanx is usually treated operatively through a mid-lateral or dorsal incision. Ogunro reported the use of a palmar longitudinal incision in a patient who had a pathological fracture and avulsion of the flexor digitorum profundus tendon. The lesion was treated with curettage, bone-grafting, and screw fixation through the palmar incision.
The use of a palmar longitudinal incision for drainage of a felon has also been described6. This approach avoids loss of sensibility in the fingertip, which may occur with a mid-lateral incision, and prevents the damage resulting from an incision that splits the nail. The postoperative scars in our three patients were barely noticeable at the time of the latest follow-up. There was no tenderness or pain, and the scar did not interfere with their daily activities. On the basis of our results, we recommend the use of a palmar longitudinal incision to treat enchondromas of the distal phalanx.