Obturator Nerve Injury: Acupuncture Points and Treatment Options

Obturator nerve injury is a clinical condition characterized by weakness of thigh adduction and limited foot abduction, among other symptoms, caused by damage, compression, or irritation of the obturator nerve from various etiologies.

The obturator nerve is formed by spinal nerves L2 and L3. It innervates the obturator externus muscle, which functions in lateral rotation of the thigh. At the obturator foramen exit, the obturator nerve gives off an anterior branch that innervates the adductor brevis and adductor longus muscles, producing adduction, flexion, and lateral rotation of the thigh; it also innervates the gracilis muscle, whose action causes adduction of the thigh and medial rotation of the leg. The cutaneous branch of the obturator nerve distributes to the skin of the lower half of the medial thigh. The posterior branch of the obturator nerve runs between the obturator externus and adductor brevis muscles to the anterior aspect of the adductor magnus (the superior part of this muscle is called the adductor minimus); the combined action of these two muscles is adduction of the thigh.

Major causes of obturator nerve injury include trauma to the medial thigh muscle group, compression and irritation from pelvic tumors, inflammation, femoral hernia, and surgical trauma.

Key Diagnostic Points

The main function of the obturator nerve is adduction of the thigh. When the obturator nerve is damaged, it manifests as…

Adduction strength of the thigh is weak, with slight abduction of the foot, and difficulty in crossing the affected foot over the healthy foot. Because thigh adduction also involves innervation from the sciatic nerve, and the pectineus muscle receives innervation from the femoral nerve, the adduction deficit is relatively mild. External rotation of the foot is also only mildly impaired, as the pectineus, gemelli, and quadratus femoris muscles still contribute.

[Treatment]

I. Acupoints and Needling Techniques (针法)

1. LR10 (Zuwuli) on the affected side: Located 2 cun lateral to CV2 (Qugu) and 3 cun directly below. Use a gauge 30, 2 cun filiform needle. Perform routine local disinfection, avoid the femoral artery and vein, and insert perpendicularly approximately 1.6 cun. Needle sensation: local distension and pain.

2. SP11 (Jimen) (affected side): Located 6 cun above SP10 (Xuehai), on the medial side of the sartorius muscle. Using a 30-gauge, 2-cun filiform needle, after routine disinfection, insert about 1.8 cun toward the femur. Needle sensation: local distension and pain.

#### 3. ST32 (Futu) – Affected Side **Location**: On the line connecting the anterior superior iliac spine (ASIS) and the lateral border of the patella, 6 *cun* directly above the superior border of the patella. **Method**: Use a No. 30 gauge, 2 *cun* filiform needle. Perform routine sterilization of the local area. Insert the needle approximately 1.8 *cun* toward the medial border of the femur. **Needling Sensation**: Local distension and pain (soreness and distention).

4. SP10 (Xuehai) (affected side): With the knee flexed, locate the point 2 cun above the medial superior border of the patella, on the bulge of the medial head of the quadriceps femoris muscle. Use a 30-gauge, 2-cun filiform needle. After routine local disinfection, insert perpendicularly to a depth of approximately 1.8 cun. Needling sensation: local distension and pain.

II. Methods

The patient is placed in the supine position. The acupoints are needled according to the standard method with the addition of electroacupuncture. The needles are retained for 40 minutes. After needle removal, cupping is applied for approximately 1 minute. Treatment is administered once daily, with 10 sessions constituting one course of treatment, followed by a 5-day rest before the next course begins.

Commentary

If the compression is of short duration and the nerve damage is not severe, and the secondary pathogenic cause has already been resolved, then applying the above method will yield relatively good results. For patients with more severe injury, although the treatment period may be longer, satisfactory outcomes can still be achieved as long as treatment is carried out patiently and carefully.

Etiology and Pathomechanics of Obturator Nerve Damage

The causes of obturator nerve damage are diverse, reflecting the nerve’s anatomical course through the pelvis and medial thigh. Iatrogenic injury during pelvic or gynecologic surgery—such as hysterectomy, lymphadenectomy, or hernia repair—remains a leading etiology due to the nerve’s proximity to the lateral pelvic wall. Traumatic causes include pelvic fractures, especially those involving the pubic rami or acetabulum, as well as hip dislocations. Compression neuropathies may arise from large pelvic masses (e.g., ovarian cysts, tumors) or from prolonged lithotomy positioning during surgery, which can stretch or compress the nerve at the obturator foramen. Additionally, intrapelvic hematomas or abscesses can exert direct pressure, leading to ischemic nerve damage. In athletes, repetitive groin strain or adductor tendinopathy may cause entrapment of the anterior branch as it pierces the adductor brevis muscle. Understanding these varied causes of obturator nerve damage is critical for early diagnosis and prevention, particularly in high-risk surgical or trauma settings.

Clinical Manifestations of Obturator Nerve Dysfunction

Patients with obturator nerve injury present with a characteristic constellation of motor and sensory deficits. The hallmark motor finding is weakness of thigh adduction, which impairs the ability to squeeze the legs together against resistance; this is best assessed by asking the patient to adduct the thigh while supine. Hip external rotation may also be weakened due to obturator externus involvement. On gait analysis, a subtle circumduction or abductor lurch may be observed as the patient attempts to compensate for adductor weakness. Sensory loss is typically confined to the medial aspect of the distal thigh, but this area is often variable and may be partially innervated by the femoral nerve. Importantly, obturator nerve injury symptoms can include neuropathic pain or paresthesias along the medial thigh and, occasionally, referred pain to the hip or groin. In severe cases, especially bilateral injury, patients may experience difficulty crossing their legs or maintaining balance during single-leg stance. These obturator nerve injury symptoms must be distinguished from other causes of groin pain, such as hip joint pathology or inguinal hernia, to guide appropriate management.

Management Strategies for Obturator Nerve Injury

Effective obturator nerve injury treatment options depend on the underlying cause, severity of deficits, and chronicity of injury. For mild, non‑disruptive neuropathies—such as transient compression from positioning—conservative measures are first-line. These include activity modification, physical therapy to strengthen synergic muscles (e.g., hip flexors and extensors), and modalities like transcutaneous electrical nerve stimulation for pain control. Pharmacologic management with gabapentin or tricyclic antidepressants may alleviate neuropathic pain. In cases of persistent motor weakness or confirmed nerve entrapment, surgical intervention becomes necessary. Options include neurolysis (decompression) of the nerve at the obturator foramen or within the adductor compartment, particularly if a mass or scar is identified. For complete transection, nerve repair or grafting using a sural nerve autograft can be attempted, though outcomes for pure motor regeneration are guarded. More recently, obturator nerve injury treatment options have evolved to include nerve transfer techniques (e.g., from the anterior branch of the obturator to the femoral nerve) in select patients with proximal injury. Postoperative rehabilitation focusing on adductor re‑education and gait retraining is essential for optimal functional recovery.