[Rehabilitation pathway after knee arthroplasty with mega prosthesis in osteosarcoma]

The knee is the most frequent location for osteosarcoma (60%). Until 30 years ago patients with osteosarcoma were treated with an amputation of the affected limb; today 85% of these cases are treated with a "Limb Salvage" procedure, through replacement of the affected bone with a mega prosthesis implant.

To measure functional recovery of patients with a knee mega-prosthesis and how rehabilitation impacts on quality of life (QOL); another aim is to define rehabilitation guidelines to manage these patients in the rehabilitation pathway.

A sample of outpatients with knee mega-prosthesis were selected in the follow-up orthopedic oncology surgery between march and may 2013. We measured the functional outcome using the multidimensional standardized Musculoskeletal Tumor Society scale (MSTS) that gives a score (0-5) for each of 7 items: pain, range of motion, stability, deformity, strength, functional activity, emotional acceptance.

The sample included 28 outpatients. The median MSTS score was 29 (min 19, max 33) equal to 83%. Only 14 patients (50%) followed a correct rehabilitation path after surgery.

21 cases got "excellent" outcomes and 3 "good" (based on MSTS classification). In few cases (n 4) the outcome was "fairly good", related to necessity of a prosthesis surgical revision based on instability of implant (because of usage). Quadricep strength is the item that most affects the final score. There is a statistically significant correlation between high scores and patients who have recently undergone surgery. We found higher scores in patients that followed a physiotherapy program after surgery: the difference was statistically significant.

Mega-prosthesis implants give satisfactory functional outcomes. These outcomes keep high score in time. It is recommended to follow the guidelines described in the purposed rehabilitation program.