Outcomes and outcome measurement instruments in lower-limb lengthening surgery: a scoping review to inform core outcome set development.

Background and purpose:  The heterogeneous outcomes used in lower-limb lengthening surgery (LLLS) complicate evidence synthesis, weakening systematic reviews and clinical recommendations, and reducing research impact. This scoping review maps the outcomes and outcome measurement instruments (OMIs) used in LLLS.

Methods: This pre-registered review systematically identified studies reporting outcomes in adults or children who underwent LLLS. Outcomes and OMIs were extracted verbatim, and experts grouped outcome terms under headings using the COMET taxonomy.

Results:  The search found 5,308 unique hits, including 149 studies from 2020-2024. They reported 2,939 verbatim outcomes, which were consolidated into 92 outcome headings and 27 subheadings. "Life impact" accounted for 13%, while "Clinical outcomes" represented 83% of all outcomes. Among the clinical outcomes, "Musculoskeletal and connective tissue" was the most reported outcome domain (68% of all outcomes). The most frequently reported outcomes were "Lengthening," "Bone healing," "Range of motion," "Limb alignment", and "Complications."

Conclusion:  Outcomes reported for people undergoing LLLS are heterogeneous and vary widely in the definitions and measurement tools used to collect them. Outcomes likely to be important to patients (life impact outcomes), such as quality of life and measures of physical function, are rarely reported.