The MAASH Technique in Total Hip Arthroplasty: A 15-Year Retrospective Study of 671 Cases without Dislocation and controlled leg length discrepancy

Background Dislocation and leg length discrepancy (LLD) are persistent challenges in Total Hip Replacement (THR), contributing to patient dissatisfaction and increased revision rates. The MAASH technique, a modification of the Hardinge direct lateral approach, preserves anterior capsular ligaments through a selective capsulotomy known as the MAASH Window. This study evaluates the long-term outcomes of the MAASH technique over a 15-year period. Methods A retrospective observational study included 671 consecutive primary THRs performed using the MAASH technique between 2010 and 2025. Radiographic analysis comprised acetabular component positioning and leg length measurements. Net leg length discrepancy (netLLD) was defined as the postoperative minus preoperative LLD, adjusted for radiographic magnification. Statistical analysis was performed using ANOVA, t-tests, and regression, with significance set at p < 0.05. Results No dislocations were reported during the 15-year span of this study. The mean netLLD was 4.8 mm (SD 4.1), with discrepancies ≤10 mm in 89.9% of cases and ≤6 mm in 78.3%. Acetabular component positioning fell within conventional safe zone parameters. A total of 25 complications (3.7%) were recorded, including periprosthetic fractures (1.5%), infections (1.3%), and aseptic loosening (0.6%). Longer surgical time (>100 minutes) was significantly associated with higher complication rates (p<0.0001). Conclusions The MAASH technique provides reliable stability and leg length control in primary THR, with zero dislocations and reduced leg length discrepancy in comparison with previous studies. Capsular preservation may play a key role in enhancing biomechanical outcomes without the need for constrained or dual mobility implants.