Anatomical locations of the motor endplates of sartorius muscle for botulinum toxin injections in treatment of muscle spasticity

Purpose This study aimed to detect the idyllic locations for botulinum neurotoxin injection by analyzing the intramuscular neural distributions of the sartorius muscles. Methods An altered Sihler's staining was conducted on sartorius muscles (15 specimens). The nerve entry points and intramuscular arborization areas were measured as a percentage of the total distance from the most prominent point of the anterior superior iliac spine (0%) to the medial femoral epicondyle (100%). Results Intramuscular neural distribution were densely detected at 20-40% and 60-80% for the sartorius muscles. The result suggests that the treatment of sartorius muscle spasticity requires botulinum neurotoxin injections in particular locations. Conclusions These locations, corresponding to the locations of maximum arborization, are suggested as the most suggestive points for botulinum neurotoxin injection.