High Hip Center Reduces the Dynamic Hip Range of Motion and Increases the Hip Load: A Gait Analysis Study in Hip Arthroplasty Patients With Unilateral Developmental Dysplasia.

BACKGROUND

Long-term favorable clinical outcomes of anatomical or high hip center techniques in total hip arthroplasty (THA) are reported in patients with developmental dysplasia of the hip (DDH). However, there is little information about the effect of the hip center location on gait characteristics. The purpose of this study was to compare these surgical techniques with gait analysis, analyze the effect of the hip rotation center location on gait parameters, and discuss the possible problems that may arise.

METHODS

A total of 40 patients who underwent THA due to unilateral coxarthrosis secondary to Crowe type III-IV DDH and completed 5 years of follow-up were included in the study. Group 1 included 20 patients who underwent anatomical hip center reconstruction, while group 2 included 20 patients who underwent high hip center reconstruction. Gait analysis was performed, and the groups were compared according to the gait characteristics.

RESULTS

The mean temporospatial values were similar between the groups. The extension of the operated side was significantly lower in group 2 (-9.11 ± 8.92) than in group 1 (-1.87 ± 11.51) (P = .04). The mean longitudinal hip joint force was found to be significantly higher in group 2 (8.92 N/kg ± 0.54) than in group 1 (8.16 N/kg ± 0.66) (P = .04). The high hip center technique has been shown to increase the load on the hip and restrict the dynamic range of motion.

CONCLUSION

The high hip center technique can decrease the survival of the implant and increase the fall risk as it increases the load on the hip and reduces the dynamic range of motion. The hip center should be reconstructed anatomically when possible in DDH patients who undergo unilateral THA.