Extensor indicis transfer versus palmaris longus transplantation in reconstruction of extensor pollicis longus tendon: a protocol for a systematic review

Abstract This review will provide an overview of published data comparing transposition of the extensor indicis pollicis (EIP) tendon and palmaris longus (PL) tendon grafting in thumb extension reconstruction following loss of the extensor pollicis longus (EPL) tendon function. We will consider all studies comparing EIP and PL utilized to reconstruct thumb extension after injury/rupture of the EPL tendon. Only studies published in the English and German literature will be included. A systematic literature research will be performed across relevant health databases including the Cochrane Library, MEDLINE, and Google Scholar using the following keywords: ((extensor pollicis longus) OR EPL) AND ((extensor indicis) OR EIP OR (tendon transposition)) AND ((palmaris longus) OR (free tendon graft) OR (tendon transplantation)). Central tendencies will be reported in terms of means and standard deviations where necessary. If not reported, the standard deviation will be calculated from the standard error of the mean. Risk ratios will be calculated where possible. All calculations will be performed with a 95% confidence interval. Statistical significance will be set at P < 0.05. Adjusted effect estimates will be analyzed in preference to the unadjusted estimates, using inverse-variance weighted average. Pooled estimates will only be presented after consideration of both clinical and methodological heterogeneity of included studies. The review will be reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Systematic review registration The protocol was registered on PROSPERO CRD42019135735: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=135735