Easily identifiable bony landmarks as an aid in targeted regional ankle blockade.

ABSTRACT

Regional anesthesia around the ankle joint is well suited to a large number of surgical procedures of the foot. Previous studies have alluded to the variable nerve distribution of the foot, which may result in incomplete blocks. The aim of the study was to determine the position of the nerves in relation to the ankle joint to easily identifiable bony and prominent soft tissue landmarks to aid more accurate targeting of these nerves. A number of 94 ankles (47 left; 47 right) were dissected to expose the tibial, sural, deep fibular (peroneal), superficial fibular (peroneal), and saphenous nerves. The distance of the nerves relative to easy to find bony landmarks was measured. A distance (alpha) was measured from the middle of the tibial nerve to the most medial aspect of the medial malleolus. Measurement beta was considered from the inferior tip of the lateral malleolus to the anterior border of the sural nerve on a horizontal plane. Measurement delta was taken from the medial border of the deep fibular (peroneal) nerve to the most anterior aspect of the medial malleolus. epsilon was measured from the middle of the superficial fibular (peroneal) nerve to the most anterior aspect of the medial malleolus on a horizontal plane. The saphenous nerve was measured (gamma) from its medial border to the most anterior aspect of the medial malleolus on a horizontal plane. Factors such as sex, length, and ankle side were also analyzed concerning their influence on the position of the nerves. This study suggests that a greater degree of certainty may possibly be attained when palpable and easy to find bony landmarks are used to determine the position of the nerves around the ankle and ensure a simple to perform, predictable, and selectively targeted block.