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Unlabelled: Limb salvage surgery is an effective procedure with a low risk of tumor recurrence. In an attempt to define the incidence of implant failure at 2, 5, and 10 years postoperatively, we retrospectively reviewed implant survival in a group (n = 105) of pediatric (< 18 years of age) and adult patients who were treated with distal femoral and/or proximal tibial implants for extremity tumors. Issues regarding the timing of failure, reason for failure, and whether pediatric patients had higher rates of failure were posed as secondary questions. The median followup was 57 months (1-235 months). Thirty-two (32/105, 31%) patients had 42 implant failures. The mean prosthesis Kaplan-Meier survivorship of the index group was 84% at 2 years, 73% at 5 years, and 59% at 10 years. Forty-seven percent of all failures occurred within 2 years postoperatively, and 69% occurred within 5 years postoperatively. Pediatric patients had a higher failure rate than adults (42% versus 24%). Aseptic loosening was the most common reason for failure (n = 18/32; 56%). The incidence of failure in tumor megaprostheses is similar to early published literature and the incidence of these failures is highest within the first 3 years., Level of Evidence: Therapeutic study, level IV.

The technique of cancellous impaction allografting with cement aims to reconstitute a bone-deficient proximal femur while also gaining stable fixation of the femoral prosthesis. Some reports of this technique imply it is a system, requiring not just an exacting surgical method, but also a particular implant design, the polished, double-tapered stem. Other series consider it a surgical technique, and have varied the femoral component design, the method of graft delivery, and other elements of the procedure. Our review evaluates the current literature, with the goal of beginning to ascertain whether published results suggest impaction grafting must be considered a system, requiring a particular stem design, or simply another means to achieve femoral reconstruction in the revision setting. The conclusive answer will require randomized, controlled clinical trials to evaluate particular elements of the procedure, and these studies have yet to be done. However, investigators have shown similarly good short-term to intermediate-term results with various femoral stems at numerous centers. Currently, femoral impaction allografting, whether as a system using particular implant designs or as a surgical technique, is an accepted alternative for revision of a failed femoral component, particularly when bone-stock deficiency is present.

Although in the proximal tibia the need for pin augmentation of cemented giant cell tumor defects depends on whether the defect is contained, there is controversy regarding the role for pins in the distal femur. The current study investigated whether Steinmann pin augmentation offers biomechanical advantages in cement reconstruction of contained defects of the lateral femoral condyle. Twelve pairs of human femurs were used. They were tested either with the bone intact, with a standardized contained defect in the lateral condyle, with a defect repaired with cement alone, and with a defect repaired with pins in the cement. Intact specimens had significantly higher load to failure than specimens with a defect. In the repaired specimens there were no significant differences in stiffness, peak load to failure, and energy to failure between the specimens repaired with just cement or augmented with pins. This study did not show any significant biomechanical advantage of this configuration of Steinmann pin reinforcement in cement for contained defects of the lateral femoral condyle.