Abstract
Introduction
Direct anterior approach (DAA) total hip arthroplasty (THA) has been reported to improve early outcomes as compared to posterior approach THA up to 6 weeks post-operatively. However, very few detailed results have been reported within the first 6 weeks. In this study we investigate the effect of surgical approach on THA outcome via weekly assessment.
Methods
Patients undergoing THA for primary osteoarthritis were prospectively enrolled. Data was collected pre-operatively and post-operatively at weekly intervals for 6 weeks. Outcome scores and additional functional measures were compared using unpaired t-test, effect size, and Pearson correlation coefficients.
Results
111 patients (55 DAA and 56 posterior approach) were enrolled. There was no significant difference (p>0.05) in pre-surgical Patient Reported Outcome Measurement Information System (PROMIS) Pain interference and Physical Function scores, VAS Pain, and Modified Harris Hip Scores (mHHS).
Post-operatively, the DAA group had decreased length of stay [1.4 vs 2.2 days, p=0.0002] and increased distance walked on postoperative day 1 and 2 [95 vs 52 ft, p=0.011 and 251 vs. 163 ft, p=0.0004, respectively]. The DAA group had lower VAS pain scores [p<0.05] and required less day 1 and total narcotics [59 vs 80 morphine equivalents, p=0.029 and 138 vs 190, p=0.01, respectively]. The DAA cohort had improved PROMIS Physical Function scores and mHHS up to 5 weeks post- operatively. Anterior approach patients discontinued their assistive device 8 days earlier [p=0.01], left home 3 days earlier [p=0.001], and drove a car 5 days earlier [p=0.016] compared to posterior patients.
Conclusion
Patients undergoing DAA THA had significantly shorter length of stay, improved mobilization, decreased narcotic requirements and improved inpatient VAS pain scores compared to mini-posterior THA. Furthermore, DAA patients discontinued their assistive device, left their home, and drove a car sooner than posterior approach patients. The significant improvement in physical function seen with DAA THA persisted up to 5 weeks post-operatively.
