Abstract
Surgical intervention for thumb duplication can be divided into three categories:
simple excision of the accessory thumb, excision of the accessory thumb with reconstruction
from available “spare parts,” and combining the two thumbs into one, as described
by Bilhaut. This prospectively PROSPERO registered systematic review evaluates the
overall, aesthetic and functional outcomes for the latter two options (reconstruction
from spare parts vs. combining two thumbs into one), aiming to facilitate evidence-based
decision making when addressing thumb duplication and direct future research. The
review was performed in accordance with the Cochrane Handbook of Systematic Reviews
and PRISMA statement. Embase, PubMed, Medline, and Cochrane databases were systematically
searched. Studies offering comparisons of techniques were included. Risk of bias was
assessed using the Risk of Bias In Non-randomized Studies—of Intervention tool. The
quality of the evidence was assessed using the Grading of Recommendations, Assessment,
Development, and Evaluation. Ten retrospective observational studies were included.
Data did not consistently allow analysis by procedure type. Four studies reported
similar overall outcomes between techniques, while two specifically reported poor
overall outcomes for the Bilhaut procedure. Two studies reported comparatively worse
aesthetic outcomes for the Bilhaut procedure with four studies reporting comparatively
improved functional outcomes for this procedure. Overall, interpretation of outcomes
was challenging with no patient-reported outcome measures used. The quality of the
evidence was universally “very low” due to all studies being at risk of methodological
bias. Based on the available evidence, surgical techniques for thumb duplication correction
appear comparable regarding overall outcome. There is limited evidence suggesting
reconstruction with spare parts offers superior aesthetic outcomes at the expense
of stability. The level of evidence is III.
Keywords
thumb duplication - congenital upper limb anomaly surgery - systematic review
