Successful Treatment of Gluteal Pain from Obturator Internus Tendinitis and Bursitis with Ultrasound-Guided Injection.

This case report describes what the authors believe is the first case of a patient with obturator internus tendinitis and bursitis successfully treated with a corticosteroid injection using a trans-tendinous lateral to medial approach. The patient presented with right gluteal pain not relieved by physical therapy or right hip and ischial bursa corticosteroid injections. Pelvic and lumbar spine MRIs and EMG/NCS findings were unremarkable. Physical examination demonstrated tenderness to palpation at the right middle lower gluteal region. Ultrasound imaging with sonopalpation identified the maximal local tender point as the right obturator internus muscle and/or its underlying bursa. A 22-gauge 3.5-inch needle was inserted in-plane to the transducer and longitudinal to the obturator internus from a lateral to medial direction, an approach previously described in cadavers. The obturator internus tendon sheath and bursa were injected with 2.5 ml of 0.5% lidocaine combined with 10 mg of triamcinolone. The patient reported immediate complete relief of pain with continued relief at 2 and 6 months post-injection. This case report demonstrates an injection of the obturator internus tendon sheath and bursa using a trans-tendinous approach, which may be successful for treatment of patients presenting with persistent gluteal pain from obturator internus tendinitis and bursitis.