Further, the pectineus muscle is occasionally (in 10%-30% of cases) innervated by the accessory obturator nerve, which arises from the anterior rami of the third and fourth lumbar nerves, descends along the medial border of the psoas major muscle, and passes above the superior pubic ramus [28, 29].
Woodburne, "The accessory obturator nerve and the innervation of the pectineus muscle," The Anatomical Record, vol.
Anatomic concerns also include branches from the femoral innervated muscles for whom trajectories are not clear, relative variability in innervation patterns to the anterior capsule in the presence of an accessory obturator nerve, accessory femoral nerve or superior gluteal nerve branches, the possibility of articular branches that start more inferiorly along the course of the femoral nerve and run with vessels, and a scenario where one common trunk supplies the joint, vessels, and muscles.
Obturator neurectomy for coxalgia; an anatomical study of the obturator and the accessory obturator nerves. J Bone Joint Surg Am.