Purpose: Direct anterior approach total hip arthroplasty (DA THA) has been reported to improve early outcomes compared to posterior approach THA up to 6 weeks postoperatively. Limited weekly outcomes data are available prior to 6 weeks. We evaluate outcomes including when patients first drive a car, leave home, and discontinue their assist device.
Methods: Patients undergoing THA for primary osteoarthritis were prospectively enrolled. Outcomes data were collected preoperatively and postoperatively at weekly intervals for 6 weeks.
Results: 111 patients (55 DA and 56 posterior approach) were enrolled. There was no significant difference (p > 0.05) in pre-surgical Patient-Reported Outcomes Measurement Information System (PROMIS) scores or modified Harris Hip Score (mHHS).Postoperatively, the DA THA group had decreased length of stay (p = 0.0002) and increased distance walked on postoperative day 1 and 2 (p = 0.011, p = 0.0004). The DA group had lower pain scores (p < 0.05) and required less day 1 and total narcotics (p = 0.029, p = 0.01). The DA cohort had improved PROMIS Physical Function scores and mHHS up to 5 weeks postoperatively. DA 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 = 0.01).
Conclusions: Patients undergoing DA THA discontinued their assistive device, left their home, and drove a car sooner than posterior approach patients. We found improvement in physical function with DA, and it persisted up to 5 weeks postoperatively. Furthermore, DA patients had significantly shorter length of stay, improved mobilisation, decreased narcotic requirements and improved inpatient pain scores compared to posterior approach THA. Future randomised controlled study should be performed to minimise the biases inherent in this study methodology and confirm the results.
Keywords: Direct anterior approach (DA); patient-reported outcome measurement information system (PROMIS); patient-reported outcome measures; posterior approach; surgical approach; total hip arthroplasty (THA).