Radiographic Results on Acetabular Cup Placement with the SuperPath Technique: A Retrospective Study of 756 Cases

Abstract

BackgroundThe Supercapsular percutaneously assisted total hip (SuperPath) technique is a relatively new minimally invasive approach for total hip arthroplasty (THA). Good clinical outcomes related to its use are reported in the literature. Nonetheless, there are still uncertainties about its validity in terms of radiographic outcomes.Purposes of the study are to evaluate the effectiveness of the SuperPath in acetabular cup positioning through radiographic evaluation of acetabular inclination angle (IA) and acetabular anteversion (AA) angle within the safe zone described by Lewinnek; to investigate cases of hip dislocation; to evaluate whether our results differ from those reported in recent literature; to evaluate whether there was a statistically significant radiographic difference in acetabular cup placement between two consecutive years.MethodsBetween January 2016 and December 2019, all SuperPath cases eligible for the study were included. They were operated by three Orthopaedic surgeons with long-standing experience in THA via traditional posterolateral approach and who have performed SuperPath training fellowship. The results were analyzed by statistical analysis.ResultsA retrospective analysis of 756 THAs was performed. Means ± standard deviation (SD) of the radiographic IA and AA were calculated for each year. The average percentage of IA within the Lewinnek's safe zone was from 80% to 85%, while the average percentage of AA was from 76% to 79%. Both IA and AA showed no statistically significant difference between two consecutive years. So, there was no statistically significant improvement regarding the radiographic values between two consecutive years for both IA and AA. There were only two cases of hip dislocations. The radiographic values were similar to recent data in the literature from authors using SuperPath and comparing their results with classical surgical approaches.ConclusionIt is possible to achieve good radiographic values of acetabular cup orientation through the SuperPath within the Lewinnek's safe zone. These results are similar to those reported in the literature by authors using SuperPath. Low rate (0,3 %) of hip dislocations were reported. Therefore, the SuperPath technique represents a good alternative for THA. Nevertheless, there is not a statistically significant improvement in these radiographic parameters over a four-year time.Level of Evidence: Level IV, retrospective study.