Preliminary clinical effect of in situ preservation of tumor bone combined with hip prosthesis in the treatment of proximal femur malignancy / 中华骨科杂志

ABSTRACT

Objective:To summarize the technical points of microwave ablation for inactivating the preserved bone in situ combined with hip prosthesis for proximal femoral malignancy and analyze its clinical efficacy.Methods:A total of 28 patients with proximal femoral malignancy who were treated in Tianjin Hospital from January 2018 to December 2021 were included in the study. There were 12 males and 16 females, aged 65.3±10.9 years (range 39-85 years); 26 metastatic bone tumors and 2 patients with proximal femoral primary tumors accompanying marrow cavity jumping focus in the study. According to whether the tumor bone mass was preserved in situ during microwave ablation, the patients were divided into the bone mass preservation group (18 cases) and conventional surgery group (10 cases). In the bone mass preservation group, according to the evaluation of preoperative CT and MRI, part of the tumor bone was preserved in situ and hip arthroplasty was performed after microwave inactivation. In the conventional surgery group, total resection of the tumor and microwave inactivation were performed firstly, and then hip prosthesis replacement was performed. Clinical efficacy was evaluated by comparing the length of osteotomy, the postoperative prosthesis stability and Musculoskeletal Tumor Society (MSTS) score.Results:The follow-up time of 28 patients was 11.9±5.9 months (range 4 to 24 months). The intraoperative length of osteotomy was 9.2±2.5 cm in the bone mass preservation group and the intraoperative length of osteotomy was 15.4±3.6 cm in the conventional surgery group, and the difference between the two groups was statistically significant ( t=5.40, P=0.002). There were 5 common hip prosthesises and 13 modular hip prosthesises in the bone mass preservation group. In 2 patients with common prosthesis, X-ray showed partial bone resorption at the osteotomy interface 3 and 8 months after operation, no loosening or fracture at the prosthesis-bone interface, and no pain or limitation of walking. There were 10 modular hip prosthesises in the conventional surgery group, with one patient suffered pain while walking at 19 months after surgery, and the X-ray suggested loosening between the prosthesis-bone interface. MSTS score of bone mass preservation group at 3 months post-operation was 16.6±1.9 points, including good 6 cases and moderate 12 case, and the excellent and good rate was 33%, meanwhile MSTS score of conventional surgery group was 15.5±3.6 points, including good 3 cases, moderate 5 cases and poor 2 cases, and the excellent and good rate was 30% at 3 months post-operation, and the difference between the two groups was not statistically significant ( t=0.94, P=0.366). MSTS score of bone mass preservation group at 6 months post-operation was 21.7±3.2 points, including excellent 3 cases, good 9 cases, moderate 1 case and poor 1 case, and the excellent and good rate was 86% (12/14), meanwhile MSTS score of conventional surgery group at 6 months post-operation was 16.5±4.9 points, including excellent 1 case, good 3 cases, moderate 3 cases and poor 2 cases, and the excellent and good rate was 44% at 6 months post-operation, and the difference between the two groups was statistically significant ( t=3.03, P=0.006). MSTS score of bone mass preservation group at 12 months post-operation was 22.3±7.6 points, including excellent 8 cases, good 2 cases, moderate 1 case and poor 1 case, and the excellent and good rate was 83% (10/12), meanwhile conventional surgery group at 12 months post-operation was 22.1±6.6 points, including excellent 3 case, good 3 cases, moderate 1 cases and poor 1 cases, and the excellent and good rate was 75%(6/8), and the difference was not statistically significant ( t=0.06, P=0.957). The MSTS scores of 6 months after operation, including movement function, acceptance degree, brace assistance and walking ability, were significantly improved in the bone mass preservation group compared with the conventional surgery group, and the differences were statistically significant ( t=2.33, P=0.030; t=2.74, P=0.012; t=2.80, P=0.011; t=2.59, P=0.026). Conclusion:Preserved bone mass in situ inactivated by microwave ablation combined with tumor hip prosthesis is an alternative surgical method for the treatment of proximal femoral malignancy, which can increase the stability of the prosthesis, facilitate the biological reconstruction of soft tissues and early functional recovery.