ObjectiveTo investigate the effectiveness of arthroscopic treatment for irreducible hip posterior dislocation caused by acetabular labrum bony Bankart lesions.MethodsBetween February 2008 and August 2016, 11 patients with irreducible hip posterior dislocation caused by acetabular labrum bony Bankart lesions, were treated with arthroscopic reduction and fixation of bony Bankart lesions. There were 7 males and 4 females, with an average age of 23.7 years (mean, 15-36 years). The injury was caused by traffic accident in 8 cases and falling from height in 3 cases. The interval between hip dislocation and the first manual reduction was 2-8 hours (mean, 5.3 hours) and between the first manual reduction and arthroscopic surgery was 6-31 days (mean, 12.8 days). The preoperative visual analogue scale (VAS) was 5.2±0.9, the modified Harris score was 32±8, and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) was 30±5. ResultsThe operative time was 90-150 minutes (mean, 120.9 minutes), with no hip arthroscopic surgery related complications. All incisions healed by first intention. All patients were followed up 26-68 months (mean, 42.7 months). Postoperative X-ray films showed that all hip joints were reduction; CT showed that the reduction of posterior acetabular wall fracture was satisfactory. And all fractures healed at last follow-up with no avascular necrosis of the femoral head or osteoarthritis. At last follow-up, the VAS score was 0.5±0.5, the modified Harris score was 94±5, and the WOMAC score was 95±4. There were significant differences in those indexes between pre- and post-operation (P<0.05). ConclusionThe irreducible hip posterior dislocation caused by acetabular labrum bony Bankart lesions is rare. Arthroscopic therapy has the advantages of less trauma, quick recovery, and less complications.