Rotational Changes in the Distal Tibial Fragment Relative to the Proximal Tibial Fragment at the Osteotomy Site after Open‐Wedge High‐Tibial Osteotomy

Abstract

The present study is aimed at assessing the changes in tibial rotation at the osteotomy site after an open-wedge, high-tibial osteotomy (OWHTO) and analysing the factors that affect rotational changes in the distal tibial fragment relative to the proximal tibial fragment at the same site. This study involved 53 patients (60 knees; 16 males and 37 females) with medial osteoarthritis (OA) who underwent OWHTO and preoperative and 3-month postoperative computed tomography (CT) scans. Rotational angles of the distal tibia were measured using Stryker OrthoMap 3D by comparing preoperative and postoperative CTs. The mean rotational angle yielded an external rotation of 2.9 ° ± 4.8 ° . There were 17 knees with internal rotations, 37 knees with external rotations, and one knee with no rotation. The rotational angle significantly correlated with the resultant change in the femorotibial angle (correction angle) and the angle between the ascending and transverse osteotomy lines on the anterior osteotomised surface on which a flange was formed with the distal tibial osteotomised surface (flange angle). The flange angle affected the rotation, but it may have been affected by our surgical technique. The rotational angle did not significantly correlate with the change in the angle of the posterior tibial slope or body mass index. There were significant correlations between the rotational angle and correction angle ( r = 0.42 , p < 0.05 ). Additionally, the rotational angle correlated with the flange angle ( r = − 0.41 , p < 0.05 ).

Hybrid Closed Wedge High Tibial Osteotomy Maintains the Leg Length after Surgery Compared to Open Wedge High Tibial Osteotomy

“…These discrepancies may be due to the sample numbers and three-dimensional changes, such as rotation of the lower limb. It was recently reported that both CWHTO and OWHTO caused rotational changes (external or internal) associated with the correction angle [15]. Regarding the h-CWHTO group, there was no correlation between the closing angle and entire leg length, as described in cases of conventional CWHTO [7,8].…”

“…William et al [14] reported that the method of osteotomy, as well as the degree of the correction angle, could affect the expected change in leg length according to preoperative planning. In cases requiring a large correction angle to correct a large varus deformity, the leg length is expected to be longer; for example, a 25-degree correction in the lower leg is expected to increase the length from 0.65 cm to 1.05 cm with conventional CWHTO, and 3.35 cm to 3.65 cm with OWHTO [15]. In summary, even with conventional CWHTO-which requires large bony resection of the tibia, as severe varus is corrected to slight valgus alignment-leg length is not always shorter.…”

Factors Causing Unintended Sagittal and Axial Alignment Changes in High Tibial Osteotomy: Comparative 3-Dimensional Analysis of Simulation and Actual Surgery

“…5,7,11,14,28 However, some authors have reported external rotation or no significant rotation, leading to a lack of consensus. 13,25 It is thought that this is because multiple factors work in combination, and each surgeon utilizes different surgical techniques.…”

“…Axial alignment changes after MOWHTO, especially tibial torsion changes, have recently gained increased interest and have been reported by several authors. 5,7,11,13,14,25,28 As the distal or proximal fragment rotates relative to the counterfragment across the osteotomy site, tibial torsion alters. Most studies have documented internal rotation of the distal fragment relative to the proximal fragment, decreasing external tibial torsion.…”

“…5,7,11,14,28 Some authors have reported external rotation or no significant rotation of distal fragments, leading to a lack of consensus. 13,25 Many studies have identified various factors related to a change in the TTA. [5][6][7]14,25,28 However, a consensus on these factors has yet to be reached.…”