Osteotomies around the knee lead to corresponding frontal realignment of the ankle

Abstract

Introduction Despite the fact that osteotomies around the knee represent well-established treatment options for the redistribution of loads and forces within and around the knee joint, unforeseen effects of these osteotomies on the ankle are still to be better understood. It was therefore the aim of this study to determine the influence of osteotomies around the knee on the coronal alignment of the ankle. We hypothesize that osteotomies around the knee for correction of genu varum or valgum lead to a change of the ankle orientation in the frontal plane by valgisation or varisation. Materials and methods Long-leg standing radiographs of 154 consecutive patients undergoing valgisation or varisation osteotomy around the knee in 2017 were obtained and utilized for the purpose of this study. Postoperative radiographs were obtained after union at the osteotomy site. The hip knee ankle angle (HKA), the mechanical lateral distal femur angle (mLDFA), the mechanical medial proximal tibia angle (mMPTA) and five angles around the ankle were measured. Comparison between means was performed using the Wilcoxon-Mann–Whitney test. Results One hundred fifty-four patients (96 males, 58 females) underwent osteotomies around the knee for coronal realignment. The mean age was 51 ± 11 years. Correction osteotomies consisted of 73 HTO, 54 DFOs, and 27 double level osteotomies. Of all osteotomies, 118 were for valgisation and 36 for varisation. For valgisation osteotomies, the mean HKA changed from 5.8° ± 2.9° preoperatively to − 0.9° ± 2.5° postoperatively, whereas the mMPTA changed from 85.9° ± 2.7° to 90.7° ± 3.1° and the malleolar-horizontal-orientation-angle (MHA) changed from 16.4° ± 4.2° to 10.9° ± 4.2°. For varisation osteotomies, the mean HKA changed from − 4.3° ± 3.7° to 1.1° ± 2.2° postoperatively, whereas the mLDFA changed from 85.7° ± 2.2° to 89.3° ± 2.3° and the MHA changed from 8.8° ± 5.1° to 11.2° ± 3.2°. Conclusion Osteotomies around the knee for correction of coronal limb alignment not only lead to lateralization or medialization of the weight-bearing line at the knee but also lead to a coronal reorientation of the ankle. This can be measured at the ankle using the MHA. When planning an osteotomy around the knee for correction of genu varum or valgum, the ankle should also be appreciated—especially in patients with preexisting deformities, ligament instabilities, or joint degeneration around the ankle.

The gap height in open wedge high tibial osteotomy is not affected by the starting point of the osteotomy

“…Open wedge high tibial osteotomy (OWHTO) for correction of varus deformity of the knee is a well-established method to redistribute loads in the axial plane [ 1 – 4 ]. Proper patient selection, deformity analysis, and preoperative planning are crucial for a successful procedure [ 2 , 5 , 6 ]. In the past two decades, advances in digitalization has led to computer based preoperative deformity analysis and osteotomy planning using imaging, improving the accuracy of malalignment correction [ 7 ].…”

Effect of Medial Closing Wedge Distal Femoral Varization Osteotomy on Coronal Ankle and Hindfoot Alignment

“…6,12,18,21,23,26 However, only a few reports have presented the changes in coronal ankle alignment after MCWDFO, without documenting hindfoot alignment changes. 16,22 Therefore, in the present study, we aimed to determine the changes in coronal ankle and hindfoot alignment after MCWDFO according to the reason for operation, as we hypothesized that preoperative hindfoot alignment and their changes would be diverse according to 2 distinct medical conditions (lateral OA or RPD). Moreover, we specifically evaluated and compared several radiographic parameters between subgroups categorized by the status of preoperative hindfoot alignment (varus, neutral, or valgus).…”

The Relationship between Frontal, Axial Leg Alignment, and Ankle Joint Line Orientation—a Radiographic Analysis of Healthy Subjects

“…A correction of leg alignment demonstrated a close relationship to the correction of AJLO and the mechanical load shift in the ankle, 8 underlining the importance of evaluating the whole kinematic chain of the lower extremities under weight‐bearing conditions. Previous studies mainly focused on the frontal leg alignment and interconnected relationship of the hip, knee, and ankle, neglecting the importance of axial alignment 7–9 . This focus solely on frontal alignment seems insufficient, as it is most likely not only frontal but also axial leg alignment and sagittal pelvic orientation, which influence the kinematic chain under weight‐bearing load and, therefore, AJLO.…”

“…Previous studies mainly focused on the frontal leg alignment and interconnected relationship of the hip, knee, and ankle, neglecting the importance of axial alignment. 7 , 8 , 9 This focus solely on frontal alignment seems insufficient, as it is most likely not only frontal but also axial leg alignment and sagittal pelvic orientation, which influence the kinematic chain under weight‐bearing load and, therefore, AJLO. This is especially of clinical relevance, when evaluating patients with concomitant joint disorders at the lower extremities either for a TAA or an axial realignment of the lower extremity.…”