Clinical applications of a novel modular hemipelvic endoprothesis with a sacral hook

Abstract

Objective To evaluate the safety and effectiveness of a novel modular hemipelvic endoprosthesis with a sacral hook.Methods Fifty-three patients (31 males and 22 females; average age,28 years) diagnosed with pelvic tumor from 2003 to 2014 were retrospectively studied.Pathological diagnoses included 22 osteosarcomas,12 Ewing's sarcomas,8 chondrosarcomas,6 metastatic malignancies,3 fibrosarcomas and 2 giant cell tumors.Initial tumor location included 23 cases of region Ⅰ+Ⅱ,12 cases of region Ⅱ+Ⅲ and 18 cases of region Ⅰ+Ⅱ+Ⅲ.All primary tumors were staged Ⅱ B according to Enneking's staging.All patients received limb-salvage surgery and reconstruction using the novel modular hemipelvic endoprosthesis with a sacral hook.Results All of 53 patients were followed for an average of 51.8 months (6-112 months).At the most recent follow-up,35 patients (66.0％) were alive,with a mean survival time of 70.6 months according to Kaplan-Meier survival analysis.18 patients (34.0％)died of tumor,with a mean survival of 28 months,and 9 patients (17.0％) experienced local recurrence at an average of 23.6months after surgery.Patients with marginal or intracapsular surgical margins had a significantly higher recurrence rate (30.4％)than those with wide margins (6.7％).Metastasis occurred in 12 cases at an average of 16 months (6-40 months) after surgery,and all patients with metastases died except one living with tumor.The total perioperative complication rate was 50.9％,including 15 cases (28.3％) of wound healing disturbances,8 cases (15.1％) of deep infection,1 case of posterior urethra injury,1 case of sciatic nerve injury,1 case of deep vein thrombosis and 1 case of pulmonary embolism.The endoprosthetic complication rate was 15.1％,including 5 cases of pubic connection plate breakage,2 cases of hip joint dislocation and 1 case of aseptic loosening of the sacral connection part.Five revision surgeries were performed for 2 septic failures and 3 aseptic failures.The estimated three year survival rate of the endoprosthesis reached 89.0％.The mean Musculoskeletal Tumor Society (MSTS 93) score was 18.2 (60.7％).Conclusion Reconstruction using the novel modular hemipelvic endoprosthesis with a sacral hook is safe and effective,whose function was satisfactory with a relatively low prosthetic complication rate. Key words: Pelvis; Bone neoplasms; Prosthesis design; Prosthesis implantation; Treatment outcome