Background. Medial open wedge high tibial osteotomy (MOWHTO) has been accepted as a highly effective option for the treatment of medial unicompartmental osteoarthritis of the knee. Although pain in the medial joint line is significantly relieved after MOWHTO, some patients complain of pain over pes anserinus after the osteotomy, necessitating implant removal for pain relief. Purpose. The purpose of this study is to define the implant removal rate after MOWHTO due to patient complaints. Methods. 103 knees of 72 patients who underwent MOWHTO for medial unicompartmental osteoarthritis between 2010 and 2018 with a follow-up of at least 24 months were enrolled in the study. Patients were evaluated with the Knee Injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS) and Visual Analogue Score (VAS) for pain in the medial knee joint (VAS-MJ). All tests were performed before the surgery, at 12 months after surgery. VAS value for pain over pes anserinus (VAS-PA) was recorded at 12 months after MOWHTO and at 3 months after implant removal. Results. Mean follow-up was 31±5.4 months. TomoFix® medial high tibia plate (DePuy Synthes, Raynham, MA, USA) was used for the fixation of osteotomy in all cases. Significant improvement in KOOS, OKS and VAS-MJ were observed 12 months after MOWHTO. Average values of VAS-MJ and VAS-PA were 21.7±7.1 and 34±8.4, respectively. Implant removal was needed for 65 (63.1%) knees. There were no significant differences in regard of postoperative KOOS (p=0.134), OKS (p=0.287) and VAS-MJ (p=0.416) scores between patients for which implant removal was needed or not. VAS-PA value decreased significantly at 3 months after implant removal (p<0.001). Conclusion. A large portion of patients needed implant removal after MOWHTO to relieve pain over pes anserinus even if knee function was significantly improved. Lower profile plates may be preferred to avoid secondary implant removal surgery after MOWHTO

Introduction. Medial open wedge high tibial osteotomy (HTO) is a generally accepted surgical method for medial unicompartmental osteoarthritis with varus malalignment of the lower extremity. However, several authors have suggested the possibility of unintentional secondary changes during open wedge HTO, which include posterior tibial slope angle (PTS) change, tibial rotation change and medial–lateral slope change of the knee joint line, may influence knee kinematics and produce poor clinical outcomes. We sought to analyze postoperative changes in three-dimensional planes using a virtual wedge osteotomy 3D model. Pre- and post-operative changes in the medial proximal tibial angle (MPTA) in the coronal plane, posterior tibial slope (PTS) in the sagittal plane, and axial tibial rotation were measured as dependent variables. And this study was attempted to determine their mutual relationships and to clarify which independent variables, including hinge axis angle and gap ratio, affect tibial rotation change and PTS change by applying the identified hinge position. Method. A total of 17 patients with 19 knees underwent HTO and were evaluated with 3D-CT before and after surgery. A 3D model was constructed by applying reverse engineering software. Results. No significant linear correlation was observed between the three dependent variables: MPTA, PTS, and rotational change. Gap ratio (β = −0.2830, p = 0.0007) and hinge axis angle (β = 0.7395, p = 0.0005) were significant factors in determining rotation change with moderate correlation (R2 = 0.546 and 0.520, respectively). In univariate regression analysis, gap ratio (p = 0.6284) and hinge axis angle (p = 0.0968) were not significant factors determining the PTS; however, after controlling for confounder, rotation change, they became statistically significant (hinge axis: β = 0.44, p = 0.0059; gap ratio: β = 0.14, p = 0.0174). Discussion and Conclusion. Unchanged axial rotation is a requisite for constant unchanged PTS, and hinge axis angle have to be considered as an important independent variable for limitation of unintended secondary changes. This study might provide clues about the low reliability of intact slope angle, That is, representability of gap ratio as slope change can be interfered by rotational change, as a confounder. Also, the current study reported the external rotation tendency of proximal tibia with increasing hinge axis angle

Introduction. Simultaneous correction of knee varus malalignment with medial open wedge high tibial osteotomy (MOWHTO) combined with anterior cruciate ligament (ACL) surgery aims to address symptomatic unicompartmental osteoarthritis in addition to restore knee stability in order to improve outcomes. The aim of this study is to present at least 5 years results of 32 patients who underwent simultaneous knee realignment osteotomy with ACL surgery. Methods. Patients with symptomatic instability due to chronic ACL deficiency or failed previous ACL surgery together with a varus malalignment of ≥6°, previous medial meniscectomy and symptomatic medial compartment pain who were treated with MOWHTO combined with ACL surgery were enrolled. ACL surgery was performed with the anatomical single bundle all-inside technique using TightRope. ®. RT (Arthrex, Naples, FL, USA) and MOWHTO using TomoFix. ®. medial high tibia plate (DePuy Synthes, Raynham, MA, USA) in all cases. Patients were evaluated preoperatively and at 6 months, 12 months and annually postoperatively using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS) and Euroqol's Visual Analogue Score (VAS) for pain. Results. 32 patients (22 men and 10 women) with a mean age of 41.2 years and mean BMI of 28.6 kg/m. 2. , underwent the combined procedures. Tibiofemoral neutral re-alignment was achieved in all patients with HTO. Complete subjective and objective scores have been obtained in 84.4% of patients with at least 5 years of follow-up (mean 8.7 years). An improvement in total KOOS of 27.1 points (p<0.003), OKS of 15.1 (p<0.003) and VAS for pain of 24.7 points (p<0.001) were detected. No ACL reconstruction failure was noted. Complications consisted of one superficial wound infection and one delayed union. Plate removal was needed in 20 (62.5%) patients due to pes anserinus pain. Conclusions. Simultaneous restoration of coronal knee axis by applying HTO and stability by ACL reconstruction/revision were reported to offer excellent improvement in early outcomes in patients with ACL rupture and symptomatic unicompartmental osteoarthritis. The combined procedure requires careful pre-operative planning and is therefore technically challenging. However, by restoring the neutral axis and providing stability, it represents a good joint preserving alternative to arthroplasty for active middle-aged patients

Purpose of the study: We conducted a prospective randomized study to compare use of macroporous biphasic calcium phosphate ceramic and bone autografts for filling medial open wedge osteotomies of the proximal tibia. Material and methods: This phase III pragmatic clinical trial was designed for direct patient benefit. Randomization was performed in the operating room after completing the osteotomy. Twenty-six men and 14 women, mean age 51 years (range 19–75 years) were included. A biomaterial implant was used for 22 patients and an autograft for 18. Mean correction was 10 mm (range 6–15). One patient was excluded from the analysis, no patient was lost to follow-up. All patients were reviewed at minimum two years follow-up. Results: At three months, knees were less painful with less subjective functional impact after filling with an autograft (pain VAS 3.1 versus 2.1 and function VAS 3.4 versus 2.5). These results were more balanced at six months (pain 1.6 versus 1.8 and function 1.8 versus 2.1) and remained stable at one and two years. The IKS knee scores were symmetrical at one at two years for both groups (IKS1 93 versus 86 and IKS2 90 versus 90). Bone healing was achieved within the usual delay. Axial alignment was stable at two years in both groups. There were eleven complications (28%), nine requiring revision: infected hematoma (n=1), intraoperative vascular injury without serious consequences (n=1), loss of correction (n=2), nonunion after filling with biomaterial (n=1), iliac abscess after filling with autograft (n=2) and painful calcification of the iliac region requiring resection (n=1). Discussion: We observed three factors which can favor mechanical failure after filling with a ceramic material: intraoperative rupture of the lateral hinge, obesity, and excessively early unprepared weight bearing. Conclusion: Although the difference did not reach significance, the risk of mechanical complications appears greater with macroporous en bloc ceramic filling. This material is less tolerant to comorbid conditions (obesity) and requires very precise technique as well as careful observance of postoperative care (no early weight bearing). Nevertheless, this method does have the advantage of avoiding painful sequelae and complications related to harvesting the iliac graft