This paper describes the development and validation of the MSTS functional evaluation system for outcomes after musculoskeletal tumor surgery. The instrument scores six domains (0–5 each) tailored to upper or lower extremity, expressing results as a percentage of normal function. The system was field-tested in 220 patients and subsequently adopted by both MSTS and ISOLS as the standard for comparative end-result studies.
Before this system existed, institutions measured motion arcs, strength grades, and deformity — anatomic surrogates that did not capture what patients could actually do or how they felt about it. There was no agreed-upon language for comparing limb salvage against amputation, or one reconstruction technique against another.
When you see MSTS scores cited in an oncology paper, this is the instrument: six domains, 0–5 each, reported as percentage of normal. Know the domains cold. They appear in board questions and define how limb salvage outcomes are benchmarked.
In the clinic, use this framework when counseling sarcoma patients before surgery. Pain, functional restriction, and emotional acceptance are each scored independently. A patient can have excellent pain control but poor function, and the system captures that nuance.
The system's known weakness (physician-administered, subjective domains) directly motivated development of patient-reported instruments like the Toronto Extremity Salvage Score (TESS) and the SF-36, which now complement MSTS scores in contemporary outcome studies. Know both exist and why.
This paper describes the development and validation of the MSTS functional evaluation system for outcomes after musculoskeletal tumor surgery. The instrument scores six domains (0–5 each) tailored to upper or lower extremity, expressing results as a percentage of normal function. The system was field-tested in 220 patients and subsequently adopted by both MSTS and ISOLS as the standard for comparative end-result studies.
Before this system existed, institutions measured motion arcs, strength grades, and deformity — anatomic surrogates that did not capture what patients could actually do or how they felt about it. There was no agreed-upon language for comparing limb salvage against amputation, or one reconstruction technique against another.
When you see MSTS scores cited in an oncology paper, this is the instrument: six domains, 0–5 each, reported as percentage of normal. Know the domains cold. They appear in board questions and define how limb salvage outcomes are benchmarked.
In the clinic, use this framework when counseling sarcoma patients before surgery. Pain, functional restriction, and emotional acceptance are each scored independently. A patient can have excellent pain control but poor function, and the system captures that nuance.
The system's known weakness (physician-administered, subjective domains) directly motivated development of patient-reported instruments like the Toronto Extremity Salvage Score (TESS) and the SF-36, which now complement MSTS scores in contemporary outcome studies. Know both exist and why.