A Systematic Review of the Outcomes of Microsurgical Toe Transfer for Metacarpal and Metacarpal-Like Hand Deformity

Background: Thumb and multiple finger amputations may result in a metacarpal and a metacarpal-like hand deformity. Toe-to-hand transfer is a recognised treatment strategy for this deformity but has risks and is resource intensive. The aim of this study is to conduct a systematic review of the outcomes of toe-to-hand transfer for traumatic metacarpal and metacarpal-like hand deformity in adult patients. Methods: Multi-database searching with index and free text terms, duplicate standardised screening and extraction, and quality assessment was performed. The inclusion and exclusion criteria were prespecified. We included any randomised controlled trials, cohort studies, case-control studies, as well as interrupted time series, before and after intervention studies. Results: Screening of 548 articles yielded 20 studies eligible that included 19 retrospective observational studies and one before and after intervention study. A total of 171 patients underwent 274 toe transfers for metacarpal and metacarpal-like hand deformity. No study compared toe-transfer to a control group or to a prosthesis. The before and after intervention study demonstrated significant improvement in activities of daily living, work, aesthetics and satisfaction. Additionally, no significant donor site morbidity occurred in the heterogenous sample. Outcomes from remaining studies at risk of bias suggest that those with a lesser severity of injury and at least two toe transfers score higher in functional tests and scoring systems. Conclusions: There is limited confidence in the effectiveness of toe transfer for metacarpal and metacarpal-like hand deformity. The available evidence indicates that toe transfer(s) may restore acceptable function permitting activities of daily living, return to original or sedentary occupation and affords satisfaction. Level of Evidence: Level III (Therapeutic).