A 42-year-old woman from Mumbai presents with a 6-month history of progressive pain in the left hip, groin, and medial thigh. She reports pain on internal rotation and flexion of the hip. Clinical examination reveals restricted internal rotation and a positive FABER test. Plain radiographs show joint space narrowing and osteophytes. MRI confirms early osteoarthritis with intact labrum. She has failed 3 months of conservative management (NSAIDs, physiotherapy, weight loss). What is the most appropriate next step in management?