Effect of patellar height changes on clinical outcomes in monoplanar and biplanar medial open wedge high medical osteotomies

The role of high tibial osteotomies in the treatment of medial compartment arthrosis is increasing day by day. Medial open wedge, lateral closed wedge and dome osteotomy are the most commonly used surgical methods. With the developing implant technology, medial open wedge high tibial osteotomy comes to the fore today. The purpose of this study is to measure the postoperative condition of the patients who underwent medial open wedge, to evaluate the patellar indices, and to measure the effect of this condition on patients' satisfaction. Patients with varus deformity and medial compartment arthrosis who underwent medial open wedge high tibial osteotomy were determined and divided into two groups. First group; The patients who were operated with the Biplanar high tibial osteotomy technique in which the tibial tubercle was left distally, and the second group was divided into patients who underwent single-plane osteotomy. Preoperative and postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) and postoperative Lysholm scores were measured in both groups. Preoperative and postoperative Caton-Deschamps (C-D) index, tibial slope (slope), and mechanical angles of the knee were calculated. Postoperative union times were recorded. Patients who underwent high tibial osteotomy with medial open wedge osteotomy technique on 59 knees of 57 patients between 2015 and 2020 at Ankara Yıldırım Beyazıt University Faculty of Medicine Orthopedics and Traumatology Clinic and fixed-angle locked HTO plate participated in the study. The ratio of patients by sex; There were 13 men and 44 women. Osteotomy was applied to the bilateral knee of 2 patients. A total of 36 were determined as right knees and 23 left knees. The mean age was 49.44 ± 7.39 (18-60). Comparison of KOOS score, Lysholm score and knee mechanical axis in the preop and last controls of the patients was found to favor a statistically significant improvement. In our study, the mean postoperative union was determined to be 9 weeks. The patient who bone union at the latest was 12 weeks. When we compared the two groups as Biplanar and Monoplanar, a significant difference was found. We observed that the biplanar type of union was earlier, albeit a little. We think that this difference is due to the biplanar type of bone contact surface being slightly higher. There is a risk of patella baja (infera) after medial open wedge high tibial osteotomy surgery. The mean preoperative C-D value of the cases in our study was calculated as 1.06 (0.72-1.39) in the monoplanar group and 1.0 (0.70-1.37) in the biplanar group. None of our patients had preoperative patella baja. The postoperative mean value of the patients was 0.90 (0.71-1.19) in the monoplanar group, and 0.97 (0.71-1.34) in the biplanar group. We could not find significant results in the differences of patellar index in these two groups. Although the patellar indices decreased a little in both groups, the values were found to be within the normal range.