Functional results after giant cell tumor operation near knee joint and the cement radiolucent zone as indicator of recurrence.

BACKGROUND Giant cell tumor of bone near the knee joints is a dilemma for the operating surgeon. Curettage and bone grafting have a high recurrence, whereas wide resection has a reduced recurrence rate with the compromise of limb function. MATERIALS AND METHODS Thirty-eight patients with histologically proven giant cell tumor near the knee joint were treated. All patients were reviewed with regard to the operative method, recurrence rate, postoperative arthritis and functional results of the joint. In cases of cement filling, the radiolucent zone and the sclerotic rim were assessed as possible markers for recurrence. RESULTS 14 male and 24 female patients were included in this study (mean age 28 years, range 13-56 years). All patients underwent surgery, 21 patients were treated with a bone cement filling and additional osteosynthesis after curettage. Seventeen patients were filled with cancellous bone or curettage alone. In the group with bone cement filling after curettage, the recurrence rate was 23.8%, whereas a recurrence rate of 52.9% was detected in the group with cancellous bone filling or curettage alone. The average time to recurrence was two years (5 months to 6 years). An increase of the radiolucent zone was seen in 80% of all patients with a recurrence. CONCLUSION Cement filling after extensive curettage does not increase the recurrence rate and does not induce osteoarthritis, as long as the continuity of articular cartilage is maintained. Patients with giant cell tumor of bone near the knee joint can be treated satisfactorily with intralesional resection and bone cement packing. The extension of the radiolucent zone after bone cement filling is a reliable indicator for a possible local recurrence.