2017 ISAKOS Biennial Congress Paper #162
Factors Related to High Tibial Osteotomy Outcome: Coronal Alignment Affect More Than Cartilage State
Wonchul Choi, MD, PhD, Sungnam-Si, Gyeonggi-Do KOREA, REPUBLIC OF
Hyunsoo Ok, MD, Bundang-Gu, Seongnam-Si, Gyeonggi-do KOREA, REPUBLIC OF
Banghyun Kim, MD, Bundang-Gu, Seongnam-Si, Gyeonggi-do KOREA, REPUBLIC OF
Uk Kim, MD, Seongnam-Si, Gyeonggi-do KOREA, REPUBLIC OF
Jae-Hwa Kim, PhD, Prof., Seung Nam, Kyenggi KOREA, REPUBLIC OF
Department of Orthopaedic Surgery, CHA University, Bundang CHA Medical Center, Sungnam-si, Gyeonggi-do, KOREA, REPUBLIC OF
FDA Status Cleared
Early outcome of medial open wedge high tibial ostotomy is determined rather by correction of coronal limb alignment than by degree of cartilage degeneration
The aim of this study was to identify the possible factors that influenced early outcome after medial open wedge high tibial osteotomy (MOWHTO).
Materials And Methods
We enrolled 87 knees (81 patients) which met the inclusion criteria in this study and collected data prospectively. Conventional MOWHTO with concomitant arthroscopy was performed and second-look arthroscopy was done at average 16 months after MOWHTO. During arthroscopy, cartilage degeneration state was evaluated by the International Cartilage Repair Society grading system. Radiographic parameters including mechanical axis (MA), medial proximal tibia angle, posterior tibia slope and patella height were measured. We defined the cases into 3 groups according to the postoperative MA; varus or less than valgus 3° as ‘Undercorrection’, between 3° and 6° as ‘Optimal’ and more than valgus 6° as ‘Overcorrection’. Subjective International Knee Documentation Committee (IKDC) scores were evaluated preoperatively and at 1 year postoperatively and factors related to postoperative IKDC score were analyzed.
All radiographic parameters were not related to postoperative IKDC score except for preoperative (R=-.327, P=.002) and postoperative MA (R=-.286, P=.007) that more valgus MA correlated to higher IKDC score. Undercorrection group (N=16) had significantly lower postoperative IKDC score compared to Optimal (N=31) and Overcorrection (N=40) group (P=.030 and P=.012). Cartilage degeneration states evaluated from first and second-look arthroscopy were not associated with postoperative IKDC score (P=.449 and P=.712). A multiple regression analysis was carried out for selected variables and more varus preoperative MA and undercorrected postoperative MA were associated with lower postoperative IKDC score (R2=.190; P=.026 and P=.042).
Our result suggests that early outcome of MOWHTO is determined rather by correction of coronal limb alignment than by degree of cartilage degeneration.