Abstract
Functional outcomes are important for patients with bone tumors undergoing lower extremity endoprosthetic reconstruction; however, there is limited empirical evidence evaluating function longitudinally. The objective of this study was to determine the changes in function over time in patients undergoing endoprosthetic reconstructions of the proximal femur, distal femur and proximal tibia.
We conducted a secondary analysis of functional outcome data from the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial. Patient function was assessed with the Musculoskeletal Tumor Society Score 93 (MSTS) and the Toronto Extremity Salvage Score (TESS), which were administered preoperatively and at 3, 6 and 12 months postoperatively. Both instruments are scored from 0-100, with higher scores indicated greater function. Mean functional scores were evaluated over time and we explored for differences among patients undergoing proximal femur reconstructions (PFR), distal femur reconstructions (DFR) and proximal tibia reconstructions (PTR). The patient-importance of statistically significant differences in function was evaluated utilizing the minimally important difference (MID) of 12 for the MSTS and 11 for the TESS. We explored for differences in change scores between each time interval with paired t-tests. Differences based on endoprosthetic reconstruction undertaken were evaluated by analysis of variance and post-hoc comparisons using the Tukey test.
A total of 573 patients were included. The overall mean MSTS and TESS scores were 77.1(SD±21) and 80.2(SD±20) respectively at 1-year post-surgery, demonstrating approximately a 20-point improvement from baseline for both instruments. When evaluating change scores over time by type of reconstruction, PFR patients experienced significant functional improvement during the 3-6 and 6-12 month follow-up intervals, DFR patients demonstrated significant improvements in function at each follow-up interval, and PTR patients reported a significant decrease in function from baseline to 3 months, and subsequent improvements during the 3-6 and 6-12 month intervals.
On average, patients undergoing endoprosthetic reconstruction of the lower extremity experience important improvements in function from baseline within the first year. Patterns of functional recovery varied significantly based on type of reconstruction performed. The results of this study will inform both clinicians and patients about the expected rehabilitation course and functional outcomes following endoprosthetic reconstruction of the lower extremity.
