Determination of injection site in flexor digitorum longus for effective and safe botulinum toxin injection

Anatomical versus functional motor points of selected upper body muscles

INTRODUCTION

In this study we aimed to identify nerve entry points (NEPs) of superficial skeletal muscles obtained by dissection of 20 human cadavers and compared them with motor points (MP) obtained previously by electrical stimulation.

METHODS

The biceps brachii (BB), trapezius (TZ), latissimus dorsi (LD), pectoralis major (Pmaj), and pectoralis minor (Pmin) muscles were dissected from human cadavers. NEP data (mean ± standard deviation) from each muscle were calculated. F-tests with Bonferroni corrections were used to compare NEPs and MPs.

RESULTS

The number of NEPs was 2 in BB, 1 in Pmin, 4 in TZ, and 3 in LD, whereas the total number in Pmaj varied from 3 to 5. NEPs and MPs were statistically equal only in Pmin and in the descending part of TZ.

DISCUSSION

The findings show crucial differences between NEPs and MPs, possibly impacting the effectiveness of several medical treatment strategies. Muscle Nerve 57: 460-465, 2018.

Localization of nerve entry points as targets to block spasticity of the deep posterior compartment muscles of the leg

To identify the optimal body surface puncture locations and the depths of nerve entry points (NEPs) in the deep posterior compartment muscles of the leg, 60 lower limbs of thirty adult cadavers were dissected in prone position. A curved line on the skin surface joining the lateral to the medial epicondyles of the femur was taken as a horizontal reference line (H). Another curved line joining the lateral epicondyle of the femur to the lateral malleolus was designated the longitudinal reference line (L). Following dissection, the NEPs were labeled with barium sulfate and then subjected to spiral computed tomography scanning. The projection point of the NEP on the posterior skin surface of the leg was designated P, and the projection in the opposite direction across the transverse plane was designated P'. The intersections of P on H and L were identified as P_H and P_L , and their positions and the depth of the NEP on PP' were measured using the Syngo system and expressed as percentages of H, L, and PP'. The P_H points of the tibial posterior, flexor hallucis longus and flexor digitorum longus muscles were located at 38.10, 46.20, and 55.21% of H, respectively. The P_L points were located at 25.35, 41.30, and 45.39% of L, respectively. The depths of the NEPs were 49.11, 54.64, and 55.95% of PP', respectively. The accurate location of these NEPs should improve the efficacy and efficiency of chemical neurolysis for treating spasticity of the deep posterior compartment muscles of the leg. Clin. Anat. 30:855-860, 2017. © 2017 Wiley Periodicals, Inc.