Background: Introduction: Piriformis syndrome is characterised by hip, buttock and lower limb pain caused by abnormal compression or irritation of the sciatic nerve as it passes through or under the piriformis muscle. Local anaesthetic infiltration of the muscle can dramatically relieve symptoms which can be considered a diagnostic sign. Analgesia from a single injection can last weeks to years.
Case Description: An 86-year-old lady with mild cognitive impairment, vitamin B12 deficiency, abdominal aortic aneurysm (AAA) and severe coronary artery disease (CAD) was admitted with a 3-day history of severe lower back pain (LBP), right gluteal pain and a new inability to weight bear, preceded by two weeks of LBP. She had no history of trauma. Orthopaedic review and imaging demonstrated non-operative degenerative disease of lumbar spine and hips. Multimodal analgesia was prescribed including paracetamol, oxycodone, morphine, tramadol, pregabalin, gabapentin, naproxen, tapentadol, transdermal buprenorphine and topical lidocaine patches. Multiple medication changes were required over a 3-week period due to ongoing pain, poor sleep and delirium. At baseline, she was independently mobile and was independent in activities of daily living. She progressed poorly with multidisciplinary team input, who noted her mobility was significantly limited by right hip pain. She required assistance to transfer from bed to chair and a wheeled Zimmer frame with moderate assistance to mobilise. The patient was assessed by the consultant pain specialist, the assessment demonstrated a positive straight leg test (SLT) test at 30 degrees on the right side, tenderness over the right piriformis muscle and positive piriformis test in side lying position. Following informed consent, she underwent an ultrasound guided right piriformis muscle injection with 10 mL 0.25% bupivacaine and 80 mg methylprednisolone with no complications and excellent analgesia immediately postprocedure (0/10 at rest, 3/10 on movement). She required no further breakthrough analgesia and described 80% improvement in her pain symptoms. Two days postprocedure she was able to mobilise 80m using a walking stick. She was discharged home a week later.
Conclusions: This case report demonstrates the important role of an interventional pain procedure in a multi-morbid older adult including reduced side effects from systemic medications, improved mobility and quality of life and earlier discharge from hospital.
