UCLA

The few available studies documenting the long-term survival of cemented proximal tibial endoprostheses for musculoskeletal tumors do not differentiate between stem designs or patient diagnosis. There is wide variation in survival rates reported, possibly a result of this heterogeneity in patient population and implant design. We therefore asked: (1) How long do proximal tibial endoprostheses last? (2) What is the typical long-term functional result after proximal tibial replacement? And (3) what are the short- and long-term complications associated with endoprosthetic reconstruction of the proximal tibia, particularly with respect to the soft tissue reconstruction? We retrospectively reviewed 52 patients with 52 proximal tibial endoprosthetic reconstructions for a tumor-related diagnosis. Kaplan-Meier survivorship analysis was performed using revision of the stemmed components for any reason as an endpoint for implants, and death due to disease progression for patients. Function was assessed using the MSTS scoring system. The minimum followup was 1 month (mean, 96 months: range, 1–284 months; median, 69 months). Using revision of the stemmed components for any reason as an end point, overall prosthesis survival at 5, 10, 15, and 20 years was 94%, 86%, 66%, and 37%, respectively. The 29 modular implants demonstrated a trend toward improved survival compared to the 23 custom-designed components, with a 15-year survivorship of 88% versus 63%. The mean postoperative Musculoskeletal Tumor Society score at most recent followup was 82% of normal function (mean raw score, 24.6; range, 4–29). Cemented endoprosthetic reconstruction of the proximal tibia provides a reliable method of reconstruction following tumor resection. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.