Extendible Prostheses for Children After Resection of Primary Malignant Bone Tumor: Twenty-seven Years of Experience.

Background: Endoprosthetic replacement in children following resection of a malignant bone tumor still is controversial because of the high number of reoperations. The aim of this study was to evaluate the long-term outcome with respect to limb-lengthening potential, satisfaction rate, and complications after implantation of extendible devices.

Methods: Seventy-one patients with a sarcoma in an extremity who had been followed for more than twenty-four months (mean, 131.6 months; range, 27.2 to 281.8 months) after tumor resection and prosthetic reconstruction with an extendible device were analyzed. The mean age at the time of the operation was ten years (range, four to sixteen years). The complication-free survival rate was evaluated with competing-risk analysis. Clinical outcomes and complications were rated with use of the Musculoskeletal Tumor Society (MSTS) score and a failure mode classification for segmental tumor endoprostheses, respectively.

Results: Twelve of seventy-one patients died of their disease. The overall MSTS score averaged 87.8% (range, 23.3% to 100%). The most common mode of failure was soft-tissue failure (46%), followed by structural failure (28%), infection (17%), and aseptic loosening (8%); only 2% of the children had local recurrence. An average of 4.4 lengthening operations per patient were required for an average limb elongation of 70.8 mm (range, 0 to 224 mm). An average of 2.5 operations (range, zero to eleven) per patient were performed for complications.

Conclusions: Although limb lengthening with an extendible endoprosthesis seems to be effective, many children have related complications. These data will be a source of preoperative information for children and parents, and will provide a benchmark for further clinical improvements.