Limb salvage surgery with the expandable prosthesis in skeletally immature children with malignant bone tumors

Abstract

Objective To evaluate the effect of expandable prostheses in skeletally immature chil-dren with malignant bone tumor after limb salvage surgery.Methods From January 2002 to December2007,clinical records of the musculoskeletal oncology department of the first affiliated hospital were re-viewed retrospectively.A total of 22 children who underwent limb salvage with the expandable prostheses were registered and included in the study.There were 20 cases with osteosarcoma and two cases with Ewing sarcoma.There were eleven males and eleven females.The patients ranged from 6 to 13 years old,with an average age of 10.7 years.The tumor was located in the distal femur in eighteen cases,in the proximal tibiae in three and in the proximal femur in one case.All patients were confirmed by preoperative needle biopsy and defined as stage ⅡB according to Enneking classification.The standardized neo-adjuvant chemotherapy was routinely performed in all patients.Results The follow-up time ranged from 24 to 86 months,with the mean of 37.63 months.One patient underwent local recurrence(4.55%).The rate of lung metastasis was18.18%(4 in 22).One patient died of complication caused by postoperative chemotherapy.Fourteen cases had undergone limb-lengthening for 34 times and achieved equal lower extremities finally.The average limb-length discrepancy was 0.4 cm after lengthening(range,0 to 1).According to Musculoskeletal Tumor Society(MSTS)functional More rating system,the mean score was 76.67%(23/30).There was no difference in the functional score between before and after the limb lengthening surgery.There were four complications related to prostheses including peri-prosthesis infection,the oblique of the knee surface,prosthesis subsidence,asep-tic loosening,and subcutaneous infection.Conclusion The expandable prostheses can not only reconstruct the bone defect after wide resection,but also offer good functional outcome.Longer follow-up is needed to confirm the promising results. Key words: Child; Limb salvage; Bone neoplasmas; Prostheses and implants