Abstract
Introduction:
The direct anterior approach for total hip arthroplasty has shown to improve multiple early outcome measures. However, criticisms suggest improved results may be due to selection bias and protocol changes. This study compares mini-incision posterior approach to direct anterior approach performed by one surgeon, controlling for influences other than the surgical approach itself.
Methods:
An IRB approved retrospective review was conducted on 150 consecutive primary total hip arthroplasty patients; the first 50 from mini-incision posterior approach, followed by 50 during the learning curve for direct anterior approach, and 50 subsequent cases when the approach was routine. Peri-operative protocols were alike for all groups. Data collection included patient demographics, anesthesia, operative times, discharge disposition, length of stay, VAS pain scores, progression from assistive devices, and narcotic use at follow-up of two and six weeks. Statistical methods included Wilcoxon rank sum, ANOVA, Kruskal-Wallis, chi-square, fisher exact and t-tests. P-value of <.05 was considered significant.
Results:
The groups were well-matched for demographics. The anterior group trended towards higher age, BMI, ASA and pre-op VAS scores. Factors favoring the anterior group reaching statistical significance included: decreased length of stay of 1.02 (learning curve) and 1.26 (routine) days (p < .0001); discharge to home instead of a rehab facility, 80% and 84% anterior versus 56% posterior (p = 0.0028); VAS pain scores at two weeks 2.7 and 2.2 anterior versus 5.2 posterior (p < .0001); less narcotic pain medication use at two weeks, 44% and 30% versus 86% (p < .0001). In the anterior groups, walker use was less at two weeks, 20% and 12% versus 74% (p < .0001) and at six weeks, 4% and 2% versus 20% (p=.0018).
Conclusion:
Primary total hip arthroplasty using the anterior approach versus the posterior approach allows for more rapid recovery in patients with no significant selection bias or protocol changes, even during the learning curve period.
