Changes in coronal alignment of the hip joint after medial opening wedge high tibial osteotomy

Abstract

Purpose An observation was made by the senior author of this paper that patients reported changes in their hip function after a medial opening wedge high tibial osteotomy (MOHTO) for varus pattern osteoarthritis. Alignment changes at the hip after MOHTO have not been previously documented. This study assesses coronal alignment changes at the hip after MOHTO. Methods We retrospectively analysed pre- and post-operative lower limb alignment radiographs of patients who underwent MOHTO. The medial proximal tibial angle (MPTA) and mechanical axis deviation (MAD) were measured to assess the alignment changes created by the MOHTO. The coronal alignment changes at the hip were evaluated using the mechanical greater trochanter angle (MGTA). Results 29 osteotomies in 27 patients were included in this study. Results showed MOHTO created alignment changes at the hip. A positive correlation was found between the size of the correction at the knee and the subsequent changes at the hip. The change in the MGTA had a stronger correlation with the MAD than with the change in MPTA (r = 0.684 vs. 0.585). It was found that age, weight, height and BMI had no significant influence on these correlations. Conclusions Increased correction by the MOHTO lead to increased change in the coronal alignment of the hip. These changes are likely to result in an alteration in the weight bearing portion of the femoral head and the function of the abductors and we recommend assessing the hip joint as part of pre-operative planning. Level of evidence Prognostic level IV.

Knee Joint Line Obliquity With Adaptational Hip and Ankle Joint Orientation After Medial Open Wedge High Tibial Osteotomy

“…Thus, theoretically, HTO of the genu varum increases the hip joint reaction force and energy consumption by the hip abductor, which could also aggravate femoral adduction due to weakness of the hip abductor over time. 1,12,26 In our study, we found a greater increase in hip adduction with time after HTO, which could be evidence of the aforementioned theoretical assumption in hip joint change (femoral adduction) and show, to the best of our knowledge, its aggravation from immediately postoperatively to 2 years after HTO. This increasing trend in femoral adduction after HTO could also be a possible cause of the consistent increase in KJLO after HTO.…”