Obturator Nerve Injury and Entrapment
Definition and Diagnosis
Damage to the obturator nerve can occur during pelvic or abdominal surgery. Although quite rare, the obturator nerve may also become spontaneously trapped where it exits the pelvis. Patients with obturator nerve injury have possible numbness and pain radiating to their inner thigh. Adduction thigh weakness can occur (ability to move the thighs together), which causes gait and posture instability. Electrical tests can help confirm the diagnosis.
If the nerve is cut and repaired at the original surgery, the prognosis is usually good, but recovery can take about one year. This is because the nerve regenerates only about one inch per month. During this interim, physical therapy is prescribed. Alternatively, if the extent of damage is uncertain after the original surgery, physical therapy is prescribed for three months during which time the nerve may recover. If the nerve doesn't recover surgical exploration may be warranted.
Alternatively, a nerve transfer procedure can be performed where a branch of the nearby femoral nerve in the groin is connected to the obturator nerve. For spontaneous obturator nerve entrapment, nerve blocks and steroid injections may be helpful. Decompression of the obturator nerve where it exits the pelvis can be performed, but the efficacy of this procedure is uncertain. Spinal cord stimulation is occasionally indicated for refractory cases.