Functional outcome after surgery in patients with bone sarcoma around the knee; results from a long-term prospective study

Background and Objectives: In a previous conducted study functional outcome of young patients with bone sarcoma located around the knee was longitudinally evaluated during the first 2 years postoperatively. Functional outcome improved significantly over the first 2 years. The purpose of this descriptive study was to evaluate the functional outcome of these patients at long-term follow-up of 7 years. Methods: Functional outcome was assessed with the TESS, MSTS, Baecke questionnaire, and three functional performance tests: time up and down stairs (TUDS), various walking activities (VWA), and the 6-min walking test (6MWT). Linear Mixed Model has been employed for the repeated measurements. Results: Twenty patients of the original study (n = 44) participated in the current study. Fifteen limb-salvage and five ablative surgery patients, median follow-up 7.4 years (6.8-8.0) (CI 95%), mean age 22.3 years (18.2-31.6). Between 2 and 7 years after surgery, 8 limb-salvage patients (53%) encountered surgery related complications. Questionnaires and functional performance tests showed no significant difference in functional outcome between 2 years and 7 years after surgery (P < 0.05). Conclusions: Between 2 years and follow-up at average 7 years after surgery no further improvements were noticed at young patients with a bone sarcoma located around the knee.