Outcome of Lower-Limb Preservation with an Expandable Endoprosthesis After Bone Tumor Resection in Children

The optimal treatment of malignant pediatric lower-extremity bone tumors is controversial. Expandable endoprostheses allow limb preservation, but the revision rate and limited function are considered barriers to their use. This study investigated the functional, emotional, and oncologic outcomes of thirty-eight patients treated with an expandable endoprosthesis.A retrospective chart review was performed, and surviving patients were asked to complete the Musculoskeletal Tumor Society (MSTS) outcomes instrument and the Pediatric Outcomes Data Collection Instrument (PODCI). Additional data including the range of hip and knee motion, limb-length discrepancy, and total lengthening were also obtained.Thirty-eight patients were treated with an expandable endoprosthesis, and twenty-six of these patients were alive at the time of the study. The mean global MSTS score was 26.1, and the mean global PODCI score was 85.8. The mean emotional acceptance and happiness subscores were high. The mean sagittal-plane hip motion in patients who had undergone replacement of the proximal aspect of the femur was 103°. The mean knee motion in patients who had undergone replacement of the proximal aspect of the femur, the distal aspect of the femur, or the proximal aspect of the tibia was 127°, 97°, and 107°, respectively. The mean lengthening at the time of skeletal maturity was 4.5 cm, and the mean limb-length discrepancy was 0.7 cm. Forty-two percent of the patients experienced complications, with ten patients requiring prosthesis revision and two of these patients requiring amputation.Current technology does not offer a single best reconstruction option for children. Previous studies and the present series have indicated that physical and emotional functioning in patients treated with an expandable endoprosthesis are good but that complication rates remain high. Amputation and rotationplasty are alternative treatments if patients and their families are amenable to these procedures. The literature supports no single superior treatment among these three options with regard to physical or emotional health.