Does curettage-cement packing for treating giant cell tumors at the knee lead to osteoarthritis?

INTRODUCTION:Giant cell tumors (GCTs) make up 15 to 20% of bone-related tumors in adults. They are often found around the knee in the metaphysis and epiphysis area, contacting the joint cartilage. The aims of our study were to evaluate the presence of early knee osteoarthritis (OA) in patients with GCTs in the knee area treated by curettage-cement packing, and to evaluate whether replacing subchondral bone with acrylic cement has an effect on the functional outcomes and quality of life. MATERIAL AND METHODS:This was a retrospective study of all patients operated between 2000 and 2010 by the same specialized surgical team. Functional outcomes and quality of life were evaluated in each patient using the Knee Injury and Osteoarthritis Outcome (KOOS), the Musculoskeletal Tumor Society Score (MSTS) and the Short Form-36 (SF-36). The presence of OA was evaluated in a full radiological work-up comparing the operated knee with the healthy contralateral knee. Knee OA was defined as grade 3 or grade 4 radiographic findings based on the Kellgren and Lawrence classification, and a significant difference between the operated and contralateral knee. RESULTS:Nineteen patients were included in this study. The average follow-up was 120 months (range 60-180). Four patients (21%) had radiographic KL-3 and one patient (5%) had KL-4. Eight patients (42%) had recurrence of the GCT. The distance between the tumor and cartilage, and the area of the subchondral bone invaded by the tumor appeared to contribute to OA progression. DISCUSSION:Resection of GCTs around the knee by curettage-cement packing did not have an effect on development of OA. In the four patients who developed knee OA, the tumor was located less than 3mm from the joint cartilage and took up more than 90% of the epiphysis. Based on these observations, there seems to be a strong correlation between the development of knee OA and the small quantity of subchondral bone left after curettage. The functional outcomes and quality of life were similar no matter the knee OA grade in patients. Replacing subchondral bone by cement had no effect on quality of life in this study. LEVEL OF EVIDENCE:IV (retrospective study).