A Comparison of Radiographic Outcomes After Total Hip Arthroplasty Between the Posterior Approach and Direct Anterior Approach With Intraoperative Fluoroscopy

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.

Does the use of intraoperative fluoroscopy improve postoperative radiographic component positioning and implant size in total hip arthroplasty utilizing a direct anterior approach?

“…In another radiographic analysis, Lin et al [6] reviewed consecutive cohorts of first posterior approach THAs followed by a series of a similar number of DAA THA patients. Postoperative radiographs were reviewed for acceptability according to established acetabular "safe zone" parameters as well as leg lengths and femoral offset.…”

“…The direct anterior approach (DAA) for total hip arthroplasty (THA) has enjoyed a recent increase in popularity [1][2][3]. Proponents note a number of purported benefits of the approach, including a modest early recovery advantage [4], low dislocation rate [5], and favorable radiographic component placement parameters [6]. One of the proposed technical advantages is that this approach is typically performed in the supine position, facilitating easy access to fluoroscopy, which theoretically can minimize errors in component placement and sizing to aid in re-establishing optimal hip biomechanics.…”

Anterior Primary Total Hip Arthroplasty

“…A higher precision and increased accuracy when implanting cup components can lead to a decreased dislocation rate [6,21]. The anterior approach also improves relation of leg length and offset [7].…”

“…Therefore, the repair of the external rotators and the capsule is of great importance in posterior THA [4]. In addition, the posterior approach is associated with an increased variance of acetabular component positioning [5][6][7]. Poor component positioning increases the risk of dislocation, facilitates increased polyethylene wear, and impingement [5,8,9].…”

Clinical, Functional and Radiographic Outcomes of Primary Total Hip Arthroplasty between Direct Anterior Approach and Posterior Approach: a Systematic Review and Meta-analysis

“…On the other hand, the conventional posterior approach (PA) is the most frequently used surgical approach for THA [9] . Some studies show that compared with the PA, the DAA leads to less blood loss, low transfusion rates, shorter surgery times, a shorter length of hospital stay (LOS), low postoperative complication rates and better functional recovery [10][11][12][13][14][15][16][17] . Other studies have shown that DAA is associated with higher postoperative complication rates than is PA [18,19] , especially regarding neuropraxia in the lateral cutaneous nerve of the thigh [18,20] .…”