Methods of nerve mapping to prevent iatrogenic nerve injuries during ankle arthroscopy: scoping review

To synthesise the literature on pre- and intra-operative nerve mapping used to prevent iatrogenic nerve injuries during ankle arthroscopy. This scoping review followed the PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. A systematic search was conducted using MEDLINE and Embase on 24 July 2024. Findings extracted from eligible studies were tabulated and synthesised. The search identified 270 articles, of which 9 met inclusion/exclusion criteria and were included in the review. Two studies described a mapping technique without reporting any outcomes, and three studies evaluated mapping techniques on cadavers and four on live patients. Four studies reported on visualisation and/or palpation, one study on arthroscopic transillumination, three on ultrasound and two on near-infrared light (NIR). There were only two comparative studies that showed that pre-operative ultrasound mapping places the nerves at safer distances from the portals and that ultrasound is more effective in the identification of the superficial peroneal nerve (SPN) than visualisation and/or palpation. Visualisation and/or palpation of the SPN is the most effective in ankle maximal plantar flexion and inversion and reduces the risk of nerve injury. There was no saphenous nerve injury with percutaneous screw insertion while using NIR. A reduction in nerve injuries during ankle arthroscopy might be achievable by using pre- or intra-operative nerve mapping with visualisation and/or palpation, ultrasound or (for nerves accompanied by the veins) NIR. The limited evidence suggests that pre-operative ultrasound might be potentially the most effective mapping method, but more comparative and prospective studies are needed to fully confirm these findings.