Abstract
BACKGROUND: Complications of thumb basal joint arthritis surgery include surgical wound pain and cheiralgia paresthetica through involvement of the radial nerve superficial branch (RNSB). The aim of this study is to compare the risk of nerve injury between anterolateral and dorsal approaches to the first carpometacarpal joint (1CMCJ) by measuring the distance between the incisions and RNSB, recording crosses between them, and evaluating the density of skin nerve endings at incision sites. METHODS: In this descriptive study of 20 cryopreserved cadaver specimens, the anatomical distribution of the RNSB and its relationship with 1CMCJ anterolateral and dorsal approaches were determined by macro-dissection, and histomorphological analysis and digital imaging were used to measure cutaneous nerve ending density at the 1CMCJ and incision sites. RESULTS: In comparison to dorsal approach, the minimum distance from the RNSB was significantly shorter (1.30 ± 1.94 mm vs 3.70 ± 2.71 mm), and the total number (16.60 ± 8.50 vs 9.97 ± 7.51) and density (2.00 ± 0.83 vs 1.29 ± 0.77 mm(2)) of nerve endings were significantly higher with anterolateral approach. With the anterolateral approach, more nerve structures were observed in the distal versus proximal section of the incision, although the difference was only close-to-significant. CONCLUSION: The incision is closer to the RNSB pathway with Wagner's anterolateral approach than with Gervis' dorsal approach, crossing with nerve branches in 50% of cases. The density of nerves is higher in the skin overlying the anterolateral versus dorsal aspect of the carpometacarpal joint. The risk of neuropathic wound pain after 1CMCJ surgery could be higher with the anterolateral approach, which should therefore be avoided.