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Variability in Acetabular Component Position in Patients Undergoing Direct Anterior Approach Total Hip Arthroplasty
Cesar R Iturriaga1, Byeongho Jung2, Michael A Mont3
1Department of Orthopaedic Surgery, Long Island Jewish Medical Center, Northwell Health, New Hyde Park, NY; Department of Orthopaedic Surgery, Plainview Hospital, Northwell Health, Plainview, NY.
Changes in acetabular component anteversion during total hip arthroplasty (THA) increase with worsening spinal pathology. Surgeons should account for this variability when positioning components in patients undergoing anterior approach THA.
Area of Science:
- Orthopedic surgery
- Biomechanical analysis
- Spine and hip biomechanics
Background:
- Hip instability after total hip arthroplasty (THA) is a common reason for revision surgery.
- Patient positioning significantly affects acetabular component alignment.
- Spinal osteoarthritis alters biomechanics, but its impact on THA component positioning during anterior approach is not well-defined.
Purpose of the Study:
- To establish guidelines for acetabular component positioning changes between supine and standing positions in primary THA via anterior approach.
- To investigate the influence of spinal pathology on acetabular component anteversion variability.
Main Methods:
- Collected perioperative pelvic and lumbar spine radiographs from 643 patients undergoing primary THA by anterior approach.
- Assessed acetabular component positioning and graded spinal pathology (Lane Grade).
- Analyzed changes in acetabular anteversion from supine to standing positions using ANOVA.
Main Results:
- Increased severity of lumbar pathology correlated with greater increases in acetabular anteversion when moving from supine to standing.
- Patients with more severe spinal pathology exhibited a trend towards lower mean supine anteversion.
- Significant differences in anteversion changes were observed across different grades of spinal pathology (P < .001).
Conclusions:
- Acetabular component anteversion demonstrates greater variability in patients with worsening spinal pathology during the supine-to-standing transition in anterior approach THA.
- Awareness of this positional variability is crucial for optimal acetabular component placement during surgery.
- These findings can inform surgical technique to potentially reduce hip instability and revision rates.
