Abstract
Introduction
Early functional recovery following total hip arthroplasty (THA) has the potential to increase patient satisfaction and reduce resource utilization. The direct anterior approach (DA) has been shown to provide earlier recovery compared to the direct lateral (DL) approach based on functional tests and outcome scores. There are limited studies that objectively evaluate functional recovery comparing the two approaches in the early post-operative period. Activity trackers have emerged as a valid tool to objectively quantify physical activity levels and potentially better assess functional status compared to commonly reported functional questionnaires. The purpose of this study is to measure physical activity levels in patients undergoing THA with the DA approach and compare these to THA with the direct lateral approach in the immediate postoperative period.
Methods
In a tertiary academic center we prospectively enrolled patients with primary OA that were eligible for a primary THA undergoing either the DA or the DL approach using the same prosthesis. Patients with comorbidities precluding them from ambulation, diagnoses of AVN or RA or undergoing bilateral THA were excluded. The number of steps walked per day were measured using wristband activity tracking technology for one week preoperatively, the first 2 weeks postoperatively and for 1 week leading up to their 6-week follow-up appointment. The University of California, Los Angeles (UCLA) activity score was also collected at the same two time points. Demographics were analyzed with descriptive statistics. A non-parametric Mann Whitney U test was used to determine whether a difference in physical activity levels exist between the DA and DL approach groups in the first 2 weeks and 6 weeks postoperatively.
Results
One hundred and thirty-nine patients with primary OA were enrolled. Seventeen were withdrawn prior to beginning the study (7 – patient requested, 5 – could not work the activity tracker, 5 – health issues). Following enrolment 29 patients were withdrawn due to lack of data available for analysis. There were 53 patients in the DA group and 40 patients in the DL group. Patient demographics including age and gender were similar in both groups. Body mass index was higher in the DL group (32.4 ± 6.9) compared to the DA group (28.2 ± 3.9) (p=0.001). There was no difference in the average steps taken per day or the UCLA score between the two groups preoperatively. The UCLA score and the overall average steps walked collected at 2 weeks postoperatively were significantly higher in the DA group compared to the DL group (median 4(1–6) vs. 3(2–6), p<0.001 and median 1641(329 – 8678) vs. 890(87 – 4347), p<0.001) respectively. When each postoperative day was evaluated individually, the DA group had a greater number of steps per day for the entire two weeks. At 6 weeks, the average number of steps taken by the DA group (median 4734 (1703 – 16605) () were greater than those taken by the DL group (median 3534 (462–8665) ± 2263) (p=0.007). A similar finding was demonstrated for the UCLA with the DA having greater self-reported activity levels (median 6 vs. 4, p<0.001).
Discussion/Conclusions
The DA approach provided faster functional recovery in the immediate postoperative period compared to the DL approach as measured by a wristband activity tracker. DA approach patients walked a greater number of steps at both 2 weeks and 6 weeks. Further examination regarding the economic implications of the improved early function from the perspective of the patient, caregiver, and care payer is indicated.
