Bilateral post-injection fibrosis of the gluteal region mimicking lumbar disc herniation: a case report

Tissue fibrosis is a known complication of intramuscular injections, which is especially seen in children due to vaccinations and injections. Herein we report a case of post injection gluteal fibrosis that had undergone two unsuccessful lumbar discectomies to treat the symptoms of this disease. A 45 years old male patient was consulted to our clinic from the department of neurochirurgy with complaints of bilateral hip pain. The patient was operated on for lumbar disc herniation in L4–5 level twice but his complaints had not resolved. A third operation including L4–5 instrumentation and fusion was planned. His examination revealed nodules in his both hips. His x-rays, MRI and blood tests were normal. He underwent bilateral gluteal fascia excision and his complaints resolved totally. The clinical diagnosis of post-injection fibrosis is problematic, due to the difficulty of determining the etiology. In many patients the diagnosis comes from a history of injection. Pain in the gluteal region is not a frequently described clinical feature of this condition. Many reports in the literature emphasize a contracture rather than pain. Post-injection fibrosis in the gluteal region may mimic lumbar disc herniation and a detailed physical examination is the key for correct differential diagnosis. In refractory cases not responding to conservative treatment, surgical excision of the nodules may lead to a complete clinical recovery of the patient.