Late post-arthroscopy hip instability. Diagnosis, treatment, and 5-year follow-up: A case report

Introduction: Hip instability following arthroscopy is a rare complication with a clinical spectrum ranging from gross dislocation (macro-instability) to micro-instability, characterized by pain and limitation for daily activities. Therefore, it should be considered as a potential differential diagnosis in patients experiencing persistent pain after hip arthroscopy. Case presentation: A 41-year-old male presented with a history of anterior hip dislocation and macro-instability symptoms three years post-hip arthroscopy. Magnetic resonance imaging (MRI) revealed a disruption of the anterior hip capsule. The patient initiated physiotherapy and resumed activities, but ten months later, experienced another anterior dislocation. Pain and apprehension during external hip rotation were evident. Threedimensional computed tomography (CT) indicated irregularities in the anterior and superior margin of the acetabulum, while MRI arthrogram showed a rupture of the anterior capsule and deficiency in the anterior hip ligaments. Open reconstruction of the anterior capsule was performed, resulting in favorable progression over the 5-year follow-up. Discussion: This case highlights post-arthroscopy hip instability with a delayed presentation, possibly linked to chronic anterior capsule deficiency and inadequate acetabular coverage. Primary capsule repair after hip arthroscopy has proven effective in reducing the occurrence of instability symptoms and reoperations. Conclusions: Post-arthroscopic hip instability may manifest immediately after surgery or several years later. Open reconstruction of the anterior capsule emerges as a successful strategy for addressing this complication, demonstrating satisfactory outcomes in a 5-year follow-up.