Possible load after initial implantation of a total hip arthroplasty (THA) – Comparison of minimal invasive anterolateral approach with direct lateral transgluteral access after Bauer

In this monocentric, non-randomised clinical study, the possible exertion of operated patients after initial implantation of a hip total arthroplasty (TEP) was investigated at the beginning and end of their postoperative early rehabilitation, depending on the surgical approach. The minimally invasive anterolateral approach was compared to the direct lateral transgluteal approach according to Bauer (standard approach). A total of 37 patients were included in this study after receiving their total hip arthroplasty. Among them, 14 patients were operated using the direct lateral transgluteal approach(TGL) according to Bauer, while 23 patients underwent surgery using a minimally invasive anterolateral approach (MIS). In addition, the collected data were compared toa comparison population consisting of 50 healthy adults who were examined using the same measurement tools in the preliminary study. Besides measuring walking speed, cadence, stance and swing phase duration, the main focus was on assessing the average ground reaction force at different walking speeds. The demographic variables (age, BMI, profession, etc.) and the pre-rehabilitative startingsituation were recorded using clinically established functional questionnaires. The above parameters were measured both in the preliminary study and in the main study using sensor insoles (Insole 3) from Moticon company (Moticon ReGo AG, Munich) on a walking distance of 30 m. The results of this study showed that the patients of the MIS group already have slight advantages in terms of functionality, ADL and pain burden compared to those of the TGL group immediately after surgery, i.e. pre-rehabilitation. Furthermore, significant differences in the symmetry of ground reaction forces during walking were observed both within each study group and in the comparison between the two groups at the beginning and end of the follow-up rehabilitation. Especially at the beginning of the follow-up rehabilitation, significant advantages of minimally invasive surgery were observed compared to transgluteal surgery in terms of ground reaction force symmetry, walking speed, stance phase duration, and the ability to walk without forearm crutches. However, the values of the healthy reference group were not reached at any time during rehabilitation in both study group.