Modern cup alignment techniques in total hip arthroplasty: A systematic review

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Radiology

Background:

• Acetabular orientation is crucial for total hip arthroplasty (THA) success.
• Conventional cup alignment may not fully account for dynamic patient kinematics.
• Novel techniques adjust for pelvic tilt, lumbo-pelvic kinematics, and spine-hip relationships.

Purpose of the Study:

• To systematically review clinical and radiological outcomes of alternative acetabular cup alignment techniques in THA.
• To assess the safety and efficacy of methods considering dynamic acetabular orientation.

Main Methods:

• Systematic review of eight studies (one level III, seven level IV).
• Data extracted on clinical and radiological outcomes from THA using alternative alignment techniques.
• Methods included computer navigation, Optimized Positioning System (OPS™), and manual instrumentation.
• Meta-analysis was not performed due to heterogeneity.

Main Results:

• Alternative THA techniques showed early dislocation rates from 0-1.9% with no catastrophic failures.
• Radiographic cup orientations were acceptable across studies.
• One comparative study found no dislocations or significant differences in patient-reported outcomes or cup positioning between kinematic and mechanical alignment.

Conclusions:

• Alternative acetabular component alignment methods, considering functional orientation, are safe and effective in the short term.
• These techniques achieve acceptable radiographic cup positioning.
• Further research is needed to compare their long-term value against conventional implantation methods.