A Comparison of Radiographic Outcomes After Total Hip Arthroplasty Between the Posterior Approach and Direct Anterior Approach with Intra-operative Fluoroscopy

• Published in: The Journal of arthroplasty Vol. 32; no. 2; pp. 616 - 623
• Main Authors: Lin, Timothy J., MD, MS, Bendich, Ilya, MD, MBA, Ha, Alex S., MD, Keeney, Benjamin J., PhD, Moschetti, Wayne E., MD, MS, Tomek, Ivan M., MD
• Format: Journal Article
• Language: English
• Published: 10.08.2016
• Subjects: Orthopedics; total hip arthroplasty; radiographic outcomes; direct anterior approach; posterior approach; acetabular inclination angle
• ISSN: 0883-5403; 1532-8406
• DOI: 10.1016/j.arth.2016.07.046

Abstract Background Radiographic outcomes after total hip arthroplasty (THA) have been linked to clinical outcomes. The direct-anterior approach (DAA) for THA has been criticized by some for providing limited exposure and compromised implant position, but allows for routine use of intra-operative fluoroscopy. We sought to determine whether radiographic measurements differed by THA approach using prospective cohorts. Methods Two reviewers blinded to surgical approach examined 194 radiographs, obtained 4-6 weeks after primary THA, and obtained measurements for acetabular inclination angle, acetabular anteversion, radiographic limb length discrepancy (LLD), and femoral offset. All surgeries were performed at a tertiary academic medical center in rural New England by an experienced fellowship-trained arthroplasty surgeon. Measurements for inclination angle, anteversion, LLD, and offset were made into binary yes/no responses based on whether the mean measurement (between the two reviewers) was acceptable or not based on established criteria. Multivariate logistic regression analyses were performed using pre-operative and intra-operative characteristics to identify predictors of acceptability for each measurement. Results The DAA group had higher rates of acceptable acetabular angle (96 vs. 85%, P=0.005), and was protective against an unacceptable angle in an adjusted predictive model (OR 0.16, P=0.005). There were no significant differences between approaches for acceptable anteversion, LLD, or offset. Body mass index of 30-34 was associated with higher odds of unacceptable inclination angle compared to the non-obese group (aOR 6.82, P=0.013). Conclusion DAA for THA was associated with lower odds of unacceptable inclination angle compared to the posterior approach, with no differences in anteversion, LLD, or offset.