Clinical Observations On Effect Of Bone Cement Reconstruction On Articular Degeneration Of The Knee After Curettage Of Giant Cell Tumor Of Bone

Objective:To evaluate the relationship between the thickness of the subchondral residual bone and articular degeneration of the knee after curettage of Giant Cell Tumor of Bone.And provide evidence for the clinical treatment of bone giant cell tumor in the future to reduce the incidence of articular degeneration.Methods:A retrospective review was conducted between January,2001 and December,2010.17 patients with GCT around knee met the inclusion criteria.There were 10 males and 7 females,aged 17~54years(mean,31.4 years),The lesion located at the distal femur in 9 cases and at the proximal tibiain in 8 cases.According to Campanacci grade,there were 6 patients at grade ? and 11 at grade ?.All patients were carried out imaging examinations before operation,and according to the subchondral residual bone thickness,all patients were divided into two groups: subchondral residual bone thickness exceed 5mm are 9,4patients at grade?and 5 at grade ?,5 cases located at the distal femur and 4 cases located at the proximal tibiain,and the average thickness of the subchondral residual bone was 7.2mm,these patients underwent curettage followed by cement reconstruction;subchondral residual bone thickness less than 5mm are 8,2 patients at grade?and 6 at grade ?,4 cases located at the distal femur and 4 cases located at the proximal tibiain,and the average thickness of the subchondral residual bone was 3.6 mm,and these patients underwent curettage followed by bone graft in the subchondral bony area and cement reconstruction.According to preoperative imaging results,we chose the medial or lateral incision of the distal femur or proximal tibia.Curettage was done through a large cortical window using a series of curettes of different sizes to remove all thevisibletumor.The cavity was then burred with a high-speed burr and washed until all pathologic tissue was removed.According to the subchondral residual bone thickness we chose curettage followed by cement reconstruction or curettage followed by bone graft in the subchondral bony area and cement reconstruction,and use the titanium plate and screw to fix.After operation,all patients were given antibiotics and zoledronic acid.According the X-ray imaging,The Aboulafia function score was used to evaluate whether secondary osteoarthritis occurred or not.Results:All incisions healed by first intention,no complications occurred.All patients were followed up.The mean follow up was 95.1 months.Of 17 cases,none had osteoarthritis.Three questionable recurrences were observed and two patients responded to zoledronic acid treatment,the other one had no changes.Conclusion: GCTs often occur around the knee joint,Surgical treatment options include curettage and filled the cavity with bone graft or cement or segmental resection and joint replacement.Compared with joint replacement after tumor resection,the tumor recurrence rate is high after curettage and bone graft or bone cement implantation,but it has good functions and less surgical complications and become the first choice.When the tumor adjacent to the cartilage,curettage of the Giant Cell Tumor followed by bone cement reconstruction can damage the cartilage and generate osteoarthritis for the reasons of subchondral bone weakened and cement exothermic reaction.After long-term follow-up,the results show that articular cartilage can be effectively protected in the premise of ensuring the thickness of the subchondral residual bone to reach 5mm through subchondral bone graft and avoid osteoarthritis.