Title : A breakthrough in post-operative care: Differentiating statin-induced necrotising autoimmune myopathy from sepsis in orthopaedic surgery
Abstract:
Background: Differentiating post-operative complications is a critical aspect of orthopaedic surgery. Necrotising autoimmune myopathy, a rare condition, can closely mimic sepsis after hip hemiarthroplasty, leading to diagnostic delays. This presentation highlights a breakthrough in the diagnostic approach to this clinical mimic.
Case Presentation: A 79-year-old male underwent a left hip hemiarthroplasty. His course was complicated by persistent pyrexia and markedly elevated inflammatory markers, with C-reactive protein (CRP) peaking at 493 mg/L. Despite extensive screening, all microbiological investigations were negative. Nine days post-operatively, he developed severe pain and rapidly progressive symmetrical quadriparesis with muscle power reduced to 1/5 and creatine kinase (CK) levels peaking at 1081 U/L. A comprehensive myositis-specific antibody panel was entirely negative, confounding the diagnosis.
Outcomes: Facing clinical deterioration, a therapeutic trial with a modest dose of 20 mg oral prednisolone was initiated. The patient demonstrated a dramatic clinical response within days. Temperature spikes ceased, inflammatory markers plummeted, and muscle power rapidly improved. He progressed from being bedridden to mobilising with a mobility aid within two weeks.
Conclusions: This case underscores a critical diagnostic challenge in geriatric orthopaedics. Statin-induced necrotising autoimmune myopathy must be a key differential in patients with unexplained post-operative weakness, extreme inflammation, and negative infectious workups, even in seronegative cases. Early recognition and a therapeutic trial of corticosteroids are crucial for optimal outcomes and represent a significant breakthrough in managing these complex post-operative complications. This case provides a strong argument for updating post-operative assessment protocols.
