Surgical access and damage extent after total hip arthroplasty influence early gait pattern and guide rehabilitation treatment

Aim. Different surgical approaches are used in total hip arthroplasty. The present study confronted two surgical techniques, analysing functional recovery in terms of activities of daily living, and ambulation using gait analy- sis, after a standardized rehabilitation protocol. Our hypothesis was that the increased surgical damage could modify the gait pattern and functional recovery. Methods. Thirty patients were randomly assigned to two homogeneous groups: Group A was treated with inter- muscular minimally invasive surgery (MIS); Group B was treated with standard lateral transmuscular approach. Follow up was planned at 30 and 90 days. Instrumental evaluation using gait analysis and functional evaluation using validated scales were performed at follow up. Results. No differences could be found as for functional scales. At the first follow up, the MIS approach proved to be the most favourable: data showed a longer duration of the swing phase, an improved range of motion of the non- treated hip, a reduced adduction (all P<0.005) and a correct timing of activation of the gluteus medium muscle on the treated side. At the second evaluation, gait analysis demon- strated some benefits of the intermuscular approach (a better flexion of both hips, and a minor obliquity of the pelvis during the terminal stance), but also advantages in the transmuscular group (better hip extension). Conclusion. Gait pattern after THA seems to be strictly dependent on surgical access and on the extent and location of surgical damage. It appears important to consider these elements in order to correctly manage the rehabilitation treatment after surgery.