Pelvic Tilt Displacement Before and After Artificial Hip Joint Replacement Surgery

Area of Science:

• Orthopedic surgery
• Biomechanical analysis
• Radiographic imaging

Background:

• Accurate acetabular implant placement in total hip arthroplasty (THA) relies on predicting pelvic displacement.
• The influence of the contralateral joint's condition on this displacement remains an area of investigation.

Purpose of the Study:

• To investigate the effect of contralateral hip joint status on pelvic displacement following THA.
• To determine if preoperative contralateral joint space width predicts postoperative pelvic tilt variations.

Main Methods:

• Computed tomography (CT) scans of 355 patients before and after THA for developmental dysplasia osteoarthritis were analyzed.
• Pelvic plane orientation was assessed using preoperative and postoperative CT.
• Patients were grouped based on contralateral hip joint space (<2 mm or ≥2 mm) and surgical approach (single or bilateral THA).

Main Results:

• Significant differences in pelvic displacement variance were observed across groups (P=.0001).
• Patients with wider contralateral joint spaces (Group W) showed significantly different displacements compared to those with minimal joint space (Group N) and single-side THA (Group P).
• A wider contralateral joint space was associated with higher variance in pelvic displacement.

Conclusions:

• Contralateral hip joint conditions demonstrably affect pelvic displacement after THA.
• The width of the contralateral joint space is a critical factor influencing the variability of pelvic displacement, impacting surgical planning.