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.

Introduction

The pathophysiology of osteonecrosis of femoral head (ONFH) is uncertain for most cases with speculation of vascular impairment and changes in cell biology due to multi-factorial etiologies including corticosteroid, alcohol, smoking, trauma, radiation or caisson disease and genetic. Extracorporeal shockwave therapy (ESWT) began with an incidental observation of osteoblastic response pattern during animal studies in the mid-1980 that generated an interest in the application of ESWT to musculoskeletal disorders. The mechanism of shockwave therapy is not fully understood but several reports showed better clinical outcomes and promoted bone remodelling and regeneration effect of the femoral head after ESWT in ONFH. Therefore, we compared the clinical results of the use of extracorporeal shock wave therapy (ESWT) on the patients with ONFH in radiographic staging.

Introduction

A large proportion of patients with osteoarthritis of the knee, present with bilateral symptoms at the outpatient department. A simultaneous total knee arthroplasty (TKA) procedure is available for such patients. The first operation in a simultaneous surgery may provide information to the operator to determine component size, soft tissue balancing, and estimate gap size for the second operation, while the second team usually conducts an operation in a confined space on the contralateral side during closure for the first operation, which can disturb cooperation during the second operation and may lead to more intra-operative surgical errors. We hypothesized that the circumstances of the two consecutive operations of a simultaneous bilateral TKA are different, could lead to different outcomes of overlapping bilateral TKAs. We therefore addressed the following research questions to determine whether there would be differences in short-term clinical outcomes, radiographic results, and implanted component size between the two sides

Background

Despite the excellent clinical success of total knee arthroplasty (TAK), controversy remains concerning whether or not to resurface the patella. This has led to a number of randomized controlled trials. Randomized controlled trials constitute the most reliable source of evidence for the evaluation of the efficacy of a potential intervention. But most of these studies include all degree of osteoarthritis of the patellofemoral joint. So we did this prospective study to compare clinical and radiological outcomes after TKA with or without patellar resurfacing in patients with grade IV osteoarthritis on patellofemoral joint.

The radiologic and clinical results of High Tibial Osteotomies (HTO) strongly rely on the accuracy of correction, and inadequate intraoperative measurements of the leg axis can lead to over or under- correction. Over the past few years, navigation systems have been proven that navigation systems provide reliable real-time intro-operative information, may increase accuracy, and improves the precision of orthopaedic surgeries. We assessed the radiological and clinical results of navigation- assisted open wedge HTO versus conventional HTO at 24 months after surgery.

A total of sixty-five open wedge HTOs were performed using navigation system and compared with forty-six open HTOs that had been performed using the conventional cable technique in terms of intraoperative leg axis assess. The Orthopilot navigation system (HTO version 1.3, B. Braun Aesculap, Tuttligen, Germany) used throughout the procedure of navigated open wedge HTO. The aim of the correction was to achieve of 3°of valgus (2–4°) on both method. For the radiological evaluation, postoperative leg axes were examined using weight bearing full-leg radiography obtained at postoperative two years after surgery. To assess correction accuracies, we compared mechanical tibiofemoral angles and intersections of the mechanical axis of the tibial plateau (%) in both groups. Outliers were defined as under-corrections of < 2° of valgus and as over-corrections of > 5° of valgus. The posterior slope of the proximal tibia was measured using the proximal tibial anatomical axis (PTAA) method. HSS (Hospital for Special Surgery) scores and ROMs (ranges of motion) were evaluated and all complications were recorded and surgical and radiation times were measured.

Navigated HTOs corrected mechanical axes to 2.8° valgus (range −3.1∼5.3) with few outliers (9.5%), and maintained posterior slopes (8.5±2.3° preoperatively and 11.0±2.8° postoperatively) (P>0.05). In the conventional group, the mean valgus correction was satisfactory (2.2° valgus), but only 67.4% were within the required range (2∼5° valgus), and 26.1% of cases were under-corrected and 6.5% of cases were over-corrected. Posterior slope increased from 8.0° to 10.6° on average without significant change after surgery. Total fluoroscopic radiation time during navigated HTO was 8.1 seconds (5∼12s) as compared with 46.2 seconds (28∼64 s) during conventional HTO (p<0.05). The surgery time for navigated HTO was 11.2 minutes longer than for conventional HTO (55.5 minutes). No specific complications related to the navigation were encountered. At clinical follow up, mean HSS scores of the navigated HTO and conventional groups improved to 91.8 and 92.5 from preoperative values of 55.3 and 55.9, respectively (p>0.05), and all patients achieved full ROM.

Navigation for HTO significantly improved the accuracy of postoperative leg axis, and decreased the variability of correction with fewer outliers, and without any complications. Moreover, it allows multi-plane measurements to be made, in the sagittal and transverse planes as well as the frontal plane intra-operatively in real time, compensates to some extent for preoperative planning shortcomings based on radiography, and significantly reduces radiation time.