Femoral Nerve Palsy Following Iliopsoas Resection: A Case Report

Case Diagnosis: Femoral nerve palsy following iliopsoas resection.

Case Description or Program Description: The case focuses on a 69-year-old female with a history notable for remote ovarian cancer, for which she previously underwent hysterectomy and oophorectomy. She was more recently diagnosed with appendiceal versus cecal primary mucinous adenocarcinoma with no evidence of metastatic or other disease. She underwent exploratory laparotomy and open partial right colectomy with en-bloc resection of the iliopsoas tumor. She had immediate weakness with right-sided hip flexion and knee extension. Despite general post-operative physical therapy, her weakness greatly limited her independence, forcing her to use assistive devices. Therefore, she was referred to PM&R clinic for evaluation.

Setting: Cancer rehabilitation clinic.

Assessment/Results: Physical examination revealed focal weakness in the right hip flexors and quadriceps. She had numbness in the anterior thigh and medial leg. Electrodiagnostic studies revealed an acute femoral nerve injury with no evidence of motor unit activity in the femoral nerve myotome. Given these results, she was re-referred to physical therapy for specific right proximal lower limb exercises and prehabilitation given upcoming plans of chemotherapy.

Discussion (relevance): Surgeries involving the iliopsoas muscle pose risks of iatrogenic nerve injury, either via direct nerve trauma, tension, or compression. Our patient likely sustained a direct injury to the femoral nerve given ongoing weakness months following surgery; the operative report notes the femoral nerve was not identified during the dissection. While prior case studies suggest femoral nerve injuries may recover with targeted physiotherapy, the diagnosis must be made accurately to direct patient care. Recognizing this can allow for early intervention and maximal function of the hip flexors and quadriceps.

Conclusions: Femoral nerve injury is a complication of iliopsoas resection that should be considered in post-operative patients with marked weakness. Physical exam and electromyography can aid in diagnosis so that targeted therapy can begin and thereby maximize functional recovery.