Modified Camitz versus flexor digitorum superficialis of the fourth finger opponensplasty in severe carpal tunnel syndrome: A systematic review

Background: Several opponensplasty techniques have been employed to address thenar muscle atrophy associated with severe carpal tunnel syndrome (CTS). Although modified Camitz opponensplasty (MCO) using the palmaris longus (PL) tendon is widely used by hand surgeons, alternative tendon transfer donors have been proposed, such as opponensplasty using the flexor digitorum superficialis of the ring finger (OF4). However, it is unclear which surgical technique provides superior outcomes. Hence, this systematic review aims to examine the difference in functional outcomes between MCO and OF4 for restoring thumb opposition in advanced CTS. Methods: A systematic search using PubMed, MEDLINE, Embase, and Scopus was performed. English-language articles reporting outcomes of opponensplasty for carpal tunnel syndrome were only included. The Mann-Whitney U test was used to compare differences in clinical outcomes. Results: 301 studies were identified and only 8 eligible studies were collected and reviewed. In both groups, the postoperative outcomes were better than the preoperative ones. Among the outcomes that could be directly compared between groups, no clear differences were found. Conclusion: Although both surgeries can provide good thumb opposition, the choice of opponensplasty technique should be based on the surgeon's experience and preference unless being performed on a patient with congenital PL tendon deficiency.