Aneurysmal bone cyst of the extremities - Factors related to local recurrence after curettage with a high-speed burr

Background: Aneurysmal bone cyst is a benign, locally destructive lesion of bone. The rates of local recurrence after curettage have varied widely The refore, we performed a retrospective study of patients who had had an aneur ysmal bone cyst in order to identify the rate of local recurrence and the p rognostic factors related to local recurrence after use of contemporary met hods of curettage with a high-speed burr. Methods: We reviewed the cases of forty patients who had been managed by th e same surgeon for an aneurysmal bone cyst, as diagnosed on the basis of th e latest pathological review, between January 1, 1976, and December 31, 199 3. The patients were evaluated with regard to age, gender, the duration and type of symptoms, the presence or absence of pathological fracture, the st atus of the growth plate, the bone and part of the bone that were involved? The type of operative procedure, the outcome, the radiographic stage, the findings on magnetic resonance imaging and computerized tomography (when it became available) and on bone scintigraphy, and histological parameters. T he median duration of follow-up was eighty-seven months (range, fifteen to 267 months). According to the criteria of Enneking, no patient had a stage- 1 lesion (one,vith a surrounding rim of cortical bone), twenty-four had a s tage-2 lesion (one with a clearly defined border but no cortical bone), and sixteen had a stage-3 lesion (one with no clearly defined border). Results: Of the forty patients, thirty-four had curettage with use of a hig h-speed burr. Of these thirty-four, twenty-two had filling of the defect wi th a cancellous autogenous graft; four, with a cancellous allograft; and th ree, with polymethylmethacrylate. In five patients, no material was put int o the defect. The remaining six patients had resection through the margin o f the lesion. Four (12 percent) of the thirty-four patients who had curetta ge had a local recurrence. No patient who had an excision through the margi n of the lesion had a local recurrence. All local recurrences were in skele tally immature girls who mere three, four, ten, and eleven gears old. Univa riate analysis with use of the chi-square, Fisher exact, and Wilcoxon log-r ank tests showed that local recurrence was associated only with a young age (p = 0.0036) and open growth plates (p = 0.039). All local recurrences occ urred within two gears postoperatively, at two, seven, nine, and twenty-fou r months, and all were treated successfully with a second operation. Conclusions: Rates of local control of almost 90 percent can be achieved wi th thorough curettage with use of a mechanical burr and without use of liqu id nitrogen, phenol, or other adjuvants in patients who have an aneurysmal bone cyst of an extremity A young age and open growth plates are associated with an increased risk of local recurrence.