The presence of spin is commonly found in the abstracts of systematic reviews and meta-analysis on robotic-assisted unicompartmental knee arthroplasty.

Purpose: As robotic-assisted unicompartmental knee arthroplasty (RA-UKA) gains popularity, debate continues over its superiority to conventional UKA (C-UKA). Systematic reviews and meta-analyses (SRMAs) have examined this, but concerns exist about spin bias in their abstracts, which can significantly alter perceptions of a treatment's efficacy and safety. This study aims to evaluate the presence of spin bias in the abstracts of SRMAs comparing RA-UKA and C-UKA, and to assess the methodological quality of all included SRMAs using the AMSTAR-2 tool.

Methods: MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews were searched from inception to 7 February 2025 for SRMAs that assessed RA-UKA. Eligible studies assessed at least one outcome of RA-UKA. Included studies were evaluated for the presence of spin in their abstracts using the methods outlined by Yavchitz et al. All full texts were subsequently assessed for methodological quality using the AMSTAR-2 tool.

Results: At least one element of abstract spin was identified in 12 of 16 included studies (75%). The most common category of spin was 'misleading reporting' in the form of selective reporting of or overemphasis on efficacy outcomes or analysis favouring the beneficial effect of the experimental intervention, observed in ten studies (63%). With the exception of one study with an overall 'low' confidence rating, all remaining studies were of 'critically low' A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR-2) confidence. No study characteristics were significantly associated with the presence of abstract spin.

Conclusion: The majority of RA-UKA SRMAs contained spin, most commonly in the form of misleading reporting and interpretation, and were rated 'critically low' in quality by AMSTAR-2. In a growing field like RA-UKA where clinical decision-making is influenced by SRMA results and conclusions, clinicians should critically review full texts to minimise the impact these biases may have on their practice.

Level Of Evidence: Level IV.