Does the direct anterior approach allow earlier recovery of walking following total hip arthroplasty? A randomized prospective trial using accelerometry

Introduction: In total hip arthroplasty (THA), the anterior approach is attractive, being intermuscular, with theoretic functional benefit. Such benefit has been frequently claimed, but there are few data from randomized comparative studies using more precise metrics than patient satisfaction. We therefore conducted a randomized trial comparing early functional results between anterior and posterior approaches on gait analysis and functional scores. Hypothesis: The study hypothesis was that there is no difference between the two approaches in terms of early recovery of walking. Materials and method: A single-center single-surgeon prospective randomized study was conducted between February 2017 and April 2018. Inclusion criteria comprised: age < 85 years, body-mass index (BMI) < 32, and hip osteoarthritis with indication for THA. Preoperatively, the 2 groups were comparable for age, gender, BMI, Charnley, Harris, Postel-Merle-d'Aubigne and Oxford-12 scores and locomotor parameters (triaxial acceleration, step regularity and walking power). Preoperative and 3-, 6- and 12week assessment comprised triaxial acceleration in walking and Postel-Merle-d'Aubigne, Harris and Oxford SF-12 scores. Results: One hundred patients were randomized to the anterior approach (AA: n = 50) and posterior approach (PA: n= 50) groups. Hospital stay was comparable between groups: PA, 2.8 +/- 1.78 days [range, 2.29-3.31 days]; AA, 2.84 +/- 1.25 days [range, 2.48-3.2 days] (p = 0.8). Operative time was significantly longer in AA: 70.1 +/- 11 minutes vs. 56.7 +/- 11.79 (p < 0.0001). There were no significant differences in locomotor parameters (p 0.122 to 0.987) or functional scores (p 0.052 to 0.968) over the 3-month follow-up. There was no difference in cup inclination: PA, 39.6 +/- 6.87 degrees [range, 37.65-41.55 degrees ] vs. AA, 37.74 +/- 4.2 degrees [range, 36.55-38.93 degrees ] (p = 0.09). There were 8/50 cases (16%) of neurapraxia of the lateral cutaneous nerve of the thigh in the AA group; rates for other complications did not differ between groups. Conclusion: Early functional results and especially objective locomotor parameters following THA were comparable between anterior and posterior approaches at 3 to 12 weeks. The approach should be chosen according to the surgeon's experience. (C) 2019 Published by Elsevier Masson SAS.