Mid-long term distal femur allograft prosthetic composite reconstruction for short proximal femur segments following tumor resection / 中华骨科杂志

ABSTRACT

Objective:To investigate the mid-to-long term therapeutic effects of allogeneic bone composite prosthesis reconstruction in patients with large bone defects after the resection of distal femoral tumors.Methods:From June 2013 to December 2018, a total of 19 patients with malignant tumors of the distal femur who underwent reconstruction with allogeneic bone composite prosthesis in the Department of Bone Tumor, Shanghai General Hospital were retrospectively collected. There were 10 males and 9 females, aged 22.3±11 years (range, 11-42 years). The mean body mass index was 19.3±3.4 kg/m 2 (range, 14-27 kg/m 2). There were 18 cases of osteosarcoma and 1 case of Ewing's sarcoma. According to Ennecking staging, there were 17 cases of stage IIB and 2 cases of stage III. The intraoperative blood loss and operation time were recorded, and the prosthesis and patient survival conditions and postoperative complications were observed. The limb function was evaluated by the Musculoskeletal Tumor Society (MSTS) 93 function score. Results:All patients successfully completed the operation. The operation time was 187.3±39.8 min (range, 110-260 min), the intraoperative blood loss was 284.9±87.0 ml (range, 200-500 ml), and the blood transfusion volume was 327±213 ml (range, 100-800 ml). The remaining length of the proximal femur was 153.7±26.6 mm (range, 93-190 mm), and the length of allogeneic bone was 84.1±24.6 mm (range, 39-134 mm). Among the 19 patients, 9 patients (47%) achieved bony union with an average healing time of 16.7±4.8 months (range, 10-25 months), and 7 patients had delayed healing with an average healing time of 18.4±4.0 months (range, 15-25 months). The remaining 10 cases were nonunion between allogeneic bone and host bone. All patients were followed up for 80.7±20.2 months (range, 56-121 months). During the follow-up, 3 cases died due to pulmonary metastasis of bone tumors, and the time of death was 57 months, 63 months, and 59 months after surgery, respectively. At the last follow-up, the patient survival rate was 84% (16/19), and the MSTS 93 function score of the 16 patients was (24.3±2.4) points (range, 21-28 points), with an excellent rate of 100% (16/16). Seven patients underwent revision surgery, 3 cases were aseptic loosening, 3 cases were prosthesis stem fracture at the junction of the allograft bone and the host bone, and 1 case was periprosthetic infection, among which the patient with periprosthetic infection had poor local soft tissue conditions due to preoperative radiotherapy, and the infection was controlled after two revision surgeries. Five cases were revised with allogeneic bone composite prosthesis, and 2 cases were revised with short-stem giant prosthesis with cortical steel plate or locking nail. After revision, the remaining length of the proximal femur was 143.4±31 mm (range, 91-175 mm), and the length of the allograft bone was 92.6±26.6 mm (range, 61-123 mm). The 7 revised patients were still in follow-up. There were no cases of pulmonary infection, nerve injury, deep vein thrombosis or other complications after surgery.Conclusion:The survival period of patients after the surgery to reconstruct large bone defects following the resection of malignant tumors at the distal end of the femur using allogeneic bone composite prosthesis is satisfactory, and the limb function is good. However, the incidence of prosthesis complications is high, which can be reconstructed through revision.