2015 ISAKOS Biennial Congress ePoster #1712

Effect of the Osteotomy Degree on the Change of the Posterior Tibial Slope with the Natural Distraction of the Gap in the Open Wedge High Tibial Osteotomy

Yong-Seuk Lee, MD, PhD, Prof., Seongnam, Kyung-gi KOREA, REPUBLIC OF
Myung Chul Lee, MD, PhD, Prof., Seoul KOREA, REPUBLIC OF
Yong Uk Kwon, MD, Seongnam KOREA, REPUBLIC OF

Seoul National University Bundang Hospital, Seongnam, Kyung-gi, KOREA

FDA Status Not Applicable

Summary: Increase of the posterior tibial slope was prevented with proper osteotomy in both uni- and bi-planar osteotomy

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Abstract:

Purpose

The purposes of this study were to 1) determine the length of the osteotomy at the anterior and posterior cortex, 2) compare between uni- and bi-planar osteotomy, and 3) evaluate the relationship between extent of the osteotomy and change of the posterior tibial slope.

Methods

A prospective comparative study of 24 uni-planar and 30 bi-planar osteotomies was performed. To evaluate the length of osteotomy, osteotomy lines of the anterior and posterior cortex were analyzed in the 3D surface models. For slope measurement, the intramedullary axis of the proximal tibia (slope P), posterior cortical line of the proximal tibia (slope C), and anterior cortical line of the proximal fibula (slope F) were used. Analysis of the changes in the posterior tibial slope was performed independently using a pre- and post-operative lateral plane radiograph.

Results

More extent of the anterior (0.91 in uni-planar vs 0.46 in bi-planar, p<0.05) and posterior (0.97 in uni-planar vs 0.79 ratio in bi-planar, p<0.05) cortical osteotomies were performed in the uni-planar osteotomy than in the bi-planar osteotomy. Further, the posterior tibial slope was maintained in both groups and the ratios between the anterior and posterior gap in both groups were 0.57 and 0.63 ratio, respectively: The maintenance of the slope was not related to any specific variables. Additionally, these phenomena did not differ between those who underwent uni- and bi-planar osteotomy.

Conclusion

Increase in the posterior tibial slope was prevented with appropriate uni- or bi-planar osteotomy with a simple distraction at the most posterior gap. However, more extent of the osteotomy was required in patients undergoing uni-planar osteotomy than those undergoing bi-planar osteotomy.