Difficulty Walking: A Pain In The Buttock

HISTORY: An 80-year-old male with history of L5-S1 minimally invasive decompression and fusion and right hamstring tear as a competitive hurdler as a teenager presented with right buttock pain for over 10 years. He also reports right-sided low back pain, however this improved after his back surgery. He did not have neurologic deficits at the time of surgery. The buttock pain occurs with walking greater than one block, is aching and dull in quality, and is rated as a 5/10, however the intensity changes based on his activity level. He denies pain radiation, numbness, tingling, weakness, or bladder or bowel incontinence. PHYSICAL EXAMINATION: Lumbar spine active range of motion was significantly limited in all planes with mild pain. There was no tenderness over the lumbar spinous processes, paraspinal musculature, or sacroiliac joints. There was tenderness at the right buttock just distal to the ischial tuberosity as well as pain and weakness with seated resisted knee flexion. Otherwise, his strength, sensation, and reflexes were intact in the bilateral lower extremities. DIFFERENTIAL DIAGNOSIS: Hamstring tendinopathy, Deep gluteal pain syndrome, Lumbar radiculitis TEST AND RESULTS: Focused ultrasound in clinic: Right hamstring tendon origin showed a large heterotopic bone just distal to the ischial tuberosity at the point of maximal tenderness and pain. CT pelvis: There is a large ossification (approximately 46 x 40 x 33 mm) along the right hamstring tendon origin, likely representing heterotopic ossification complicating hamstring detachment. FINAL WORKING DIAGNOSIS: Large heterotopic ossification in proximal hamstring tendon due to avulsion 65 years prior while competing as a hurdler as a teenager. Buttock pain is long-term sequelae of this injury as an athlete that had become more symptomatic over time as he lost muscle mass to compensate for the tear. TREATMENT AND OUTCOMES: Physical therapy for eccentric strengthening of hamstrings, core and hip girdle strengthening and stabilization, and improvement of gait and balance. If no improvement in pain with physical therapy, consideration of a diagnostic injection into the hamstring tendon and heterotopic ossification. If therapeutic for pain relief, will consider a platelet rich plasma injection. Follow up in 2-3 months.