Abstract
Introduction
The usefulness of minimal invasive hip replacement is frequently discussed but there is a lack of data on the effect of the surgical approach on early results. We wanted to study the effect of the surgical approach on the peri- and early postoperative outcome.
Material/Methods
In a prospective case control study 315 elective hip replacements were performed between January 2008 and March 2010. Until March 2009 a lateral transgluteal approach (STD) was used, then the approach was changed to a minimal invasive anterior approach (MIS). All operations were performed in the same routine setting not affected by the approach. Duration of operation, complications and bloodloss were assessed. 1 week postoperatively, independent mobility, stairs, central analgetics were analysed and length of stay was recorded. At 6 and 12 weeks, pain and patients satisfaction (VAS) and the Harris Hip Score were assessed.
Pre- and postoperative radiographs were compared for component position and orientation (EBRA).
Results
6 patients (hips) refused participation, 4 were excluded for other reasons. 174 (57%) hips belonged to STD and 131 (43%) to MIS. There were no demographic differences between both groups.
Operation time was longer for MIS (109 vs. 123 min, p=.001). At 1 week, MIS patients were more mobile (rising up from bed, p=.009; stairs, p=.015) and time of hospitalisation became shorter (p=.001).
At 6 weeks, MIS patients had less pain at motion (p=.013), less limb (p=.001), a higher HHS (p=.007) and were more satisfied (p=.046). The differences remained unchanged after 12 weeks.
There was no difference in implant positioning between the groups. Inclination was higher in group MIS [39° (SD 6°) vs. 38° (SD 7°), p=.030], anteversion was lower [21° (SD 8°) vs. 24° (SD 8°), p=.010].
Conclusion
The introduction of the MIS anterior approach was safe. Early rehabilitation was facilitated and clinical results were better. Radiographical results were not impaired by the new approach. We see no disadvantage of the MIS anterior approach. Adaptions in the clinical setup might further facilitate rehabilitation.
