Neurovascular and tendon injuries due to ankle arthroscopy portals: a meta-analysis of interventional cadaveric studies

Neurovascular and tendon structures are considered at risk when performing ankle arthroscopy. Injury rate and distance from portals to such structures varied in the literature. The aim of this meta-analysis is to evaluate the injury risk of these structures in terms of proximity and injury prevalence. Thirteen studies including 184 cadaveric ankle arthroscopy procedures met the inclusion criteria. The antero-central portal exhibited the highest frequencies of nerve/vessel proximity and nerve/vessel missed injuries. Weighted mean distances were as follows: 2.76 ± 2.37 mm for the superficial fibular nerve (SFN) to the antero-lateral portal, 8.13 ± 2.45 mm for the saphenous nerve to the antero-medial portal, 2.1 ± 1.7 mm for the dorsalis pedis artery (DPA) to the antero-central (AC) portal, 6.84 ± 2.59 mm for the sural nerve to the postero-lateral portal. Distances to the postero-medial portal were 7.82 ± 2.98 and 11.03 ± 3.2 mm for the posterior tibial nerve and the posterior tibial artery, respectively. A total of 14 (10.3%) nerve injuries and 17 (12.5%) missed nerve injuries with a cumulative frequency of 22.8% of nerve structure at high risk. The SFN was the most vulnerable (10.3% of injury/missed injury), and it was the closest nerve to a portal. Vascular involvement consisted of 2 (1.5%) injuries and 12 (8.8%) missed injuries with the DPA being the most vulnerable (20%) through the AC portal. Tendon injuries were found in 8.7% procedure acts. The injury rates of extra-articular structures were found to be higher than previously reported in clinical literature. Apart from clinical studies, distance to portals and missed injuries of these structures could be evaluated. This cadaveric meta-analysis yielded more accurate results over the proximity and potential injury risk of ankle noble structure and should incite surgeons for more attention during portal placement. Such anatomical meta-analyses could offer an excellent statistical model of evidence synthesis when assessing injury risk in mini-invasive surgeries.