2015 ISAKOS Biennial Congress ePoster #1728

The Importance of Complete Osteotomy at the Anterolateral Connection During Biplanar High Tibial Osteotomy

Woonhwa Jung, MD, Changwonsi, Gyeongnam KOREA, REPUBLIC OF
Jae-Heon Jeong, MD, Seoul, Seoul KOREA, REPUBLIC OF

Department of Orthopaedic Surgery, Murup Hospital , Changwon-si, Gyeongnam , KOREA

FDA Status Cleared

Summary: The complete osteotomy at the anterolateral connection area during the biplanar medial opening-wedge HTO is necessary for preventing the lateral cortical hinge fracture.

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Abstract:

Introduction

There have been few reports on the incidence of the intraoperative lateral cortical hinge fracture(LCHF), which are a possible complication of medial opening-wedge high tibial osteotomy(MOWHTO). There was no report concerning the incidence of the intraoperative LCHF based on the magnetic resonance imaging (MRI).The purpose of this study was to determine the incidence and pattern of intraoperative lateral cortical hinge fractures after medial opening-wedge high tibial osteotomy based on the simple radiograph and magnetic resonance imaging.

Methods

From December 2012 to June 2013, the senior author performed 100 consecutive medial-opening-wedge high tibial osteotomies in 100 patients. We checked the supine anteroposterior and lateral radiographs of the knee immediate postoperatively and the magnetic resonance imaging at 3 days postoperatively. Based on the simple radiographs and MRI, we assessed the intraoperative lateral cortical hinge fractures. Intraoperative lateral cortical hinge fractures were classified as follows: type I, the fracture reaches just upward or straightly of the osteotomy plane; type II, the fracture reaches downward of the osteotomy plane; and type III, the fracture reaches upward to lateral tibial plateau. We divided the knee in to 2 groups according to the intraoperative lateral cortical hinge fractures. Moreover, we evaluated the correlation between other variables and intraoperative lateral cortical hinge fractures.

Results

On immediate postoperative simple radiographs, intraoperative lateral cortical hinge fractures were observed in 5 knees (5%): 5 type I, 0 type II, and 0 type III. On postoperative magnetic resonance imaging, intraoperative lateral cortical hinge fractures were observed in 44 knees (44%): 33 type I, 7 type II, and 4 type III. On MRI, unintended bone beak at the anterolateral connection area of the two osteotomy plane was found in 75 knees. Significant differences were noted in inserted wedge size between fracture group and non-fracture group (P=.001). No significant differences were noted in inserted wedge size between beak group and non-beak group (P=.243). The bone beak was the only factor found to be significantly correlated with LCHF (P=.001, Odds ratio=8.843).

Discussion And Conclusion

During medial opening-wedge high tibial osteotomy, there is significantly higher incidence of the lateral cortical hinge fracture based on MRI, compared with immediate postoperative simple radiaographs. The complete osteotomy at the anterolateral connection area during the biplanar MOWHTO is necessary for preventing the bone beak to be correlated with LCHF.