Plantar Pressure Analysis after Medial Opening Wedge High Tibial Osteotomy Treatment of Medial Single Compartmental Knee Osteoarthritis / 医用生物力学

Objective To analyze the plantar pressure distribution of knee osteoarthritis ( KOA) patients after medial opening wedge high tibial osteotomy ( MOWHTO), so as to provide biomechanical references for the surgical treatment and rehabilitation of patients. Methods A total of 31 patients with medial single compartmental KOA after unilateral MOWHTO treatment were selected as the experimental group, and 35 healthy subjects at same age were selected as the control group. The Pedomedic 40 􀅺 pressure measuring system was used to test dynamic plantar pressure. By comparing the maximum pressure ( pmax ), force-time integral ( FTI) and contact area (CA) of different plantar zones between the experimental group (operative side and unoperated side) and the control group during walking, the changes of plantar pressure in patients with medial single compartmental KOA after MOWHTO were evaluated. Results Compared with the unoperated side and the control group, the CA and FTI of the 1st metatarsal head (MH1) were higher (P<0. 05), the CA of the 4th metatarsal head (MH4)was smaller (P<0. 001), the pmax and FTI of the 5th metatarsal head (MH5) were smaller (P<0. 05), the CA of the lateral middle foot (MF-L) was smaller (P<0. 001), and the CA of the medial rear foot (RF-M) was larger (P<0. 05). Compared with the control group, the pmax of MH1 and MH2 was smaller (P<0. 05), the CA and FTI of MH5 were larger (P<0. 05), the pmax of MF-L was larger (P<0. 001), and the FTI of lateral rear foot (RF-L) was larger (P<0. 05). Conclusions Compared with healthy people, patients with medial single compartmental KOA have abnormal plantar pressure residual after MOWHTO. In clinical practice, targeted intensive rehabilitation therapy is necessary to restore the normal plantar distributions of patients.

Stress Distributions Affected by Different Filling Blocks in Medial Opening Wedge High Tibial Osteotomy / 医用生物力学

Objective To analyze the influence from material and size of the filling block on stress distributions of the tibial osteotomy model. Methods The filling blocks with three different materials (iliac bone, cancellous bone and polyetheretherketone (PEEK)) and five different sizes were established and implanted to the tibial osteotomy models, respectively. The mechanical loads were applied on the model, the stress distribution and edge displacement of the model were analyzed. Results For three kinds of materials, the stress at proximal end of the tibia and the plate, as well as edge displacement in the model implanted with filling block by iliac bone material were lower than those of the cancellous bone and PEEK, but the filling block by iliac bone material had the highest stress. When the filling blocks with different sizes were implanted in osteotomy space, the stress distribution on each part of the tibial osteotomy and edge displacement were different. Especially when the width of the filling block was reduced from 30 mm to 10 mm, the peak stress of the proximal tibia, steel plate and filling block was increased by 49. 3% , 92. 7% and 54. 4% on average. Conclusions Different filling block parameters will affect the stress distribution in different parts of the tibial osteotomy. The research results provide the theoretical basis for parameter selection of the tibial osteotomy filling block in clinic.

Early effectiveness analysis of lateral hinge fracture during medial opening-wedge high tibial osteotomy / 中国修复重建外科杂志

Objective: To compare the clinical and radiologic effectiveness in patients with versus without lateral hinge fracture during medial opening-wedge high tibial osteotomy (MOWHTO) to evaluate the effect of lateral hinge fracture on short-term effectiveness. Methods: The clinical data of 84 patients (97 knees) with medial compartment osteoarthritis who treated with MOWHTO between September 2015 and July 2018 was retrospectively analyzed. There were 10 males (10 knees) and 74 females (87 knees). The age ranged from 45 to 65 years with an average of 57.7 years. Lateral hinge fracture was recognized by the intraoperative fluoroscopy or immediate postoperative X-ray film. Fractures were classified into types Ⅰ, Ⅱ, and Ⅲ according to the Takeuchi classification. The healing of osteotomy was observed by radiographs during follow-up; the femur tibia angle (FTA), medialproximal tibial angle (MPTA), and hip-knee-ankle angle (HKA) were also calculated. The knee joint function was evaluated by Hospital for Special Surgery (HSS) score and knee society score (KSS). Results: The incision healed by first intention. All patients were followed up 15-48 months with an average of 24.8 months. No hinge fracture occurred in 78 knees (80.41%, group A), and lateral hinge fractures were observed in 19 knees (19.59%, group B) and were divided into the type Ⅰ (13 knees, 13.40%) and type Ⅲ (6 knees, 6.19%) groups. Type Ⅰ fractures were not additionally treated, type Ⅲ fractures were anatomic reduced fixed with additional lag screws. X-ray film and CT examination showed that all patients had bone healing at 3 months after operation without delayed healing or nonunion. During follow-up, there was no loosening or fracture of internal fixation plates and screws. HKA, FTA, and MPTA of patients in group A and group B (type Ⅰ and Ⅲ) were significantly improved at each time point after operation compared with preoperative values ( P0.05). After operation, the pain of knee joint was alleviated and the function of joint was improved. At last follow-up, KSS score and HSS score of groups A and B were significantly improved compared with those before operation ( P0.05). Conclusion: The lateral hinge fracture may occur during MOWHTO. As long as the treatment and rehabilitation were guided according to the fracture classification of the hinge, the effectiveness can be similar to those without the hinge fracture.

Distal Femoral Medial Opening Wedge Osteotomy for Post-Traumatic, Distal Femoral Varus Deformity

Restoration of neutral mechanical alignment of the lower limb is an important factor in the treatment of unicompartmental arthrosis. Traditionally, medial opening wedge high tibial osteotomy has been widely performed to correct varus malalignment with unicompartmental arthrosis. However, an ideal indication for the high tibial osteotomy is the knee with metaphyseal tibial varus malalignment. The basic principle of corrective osteotomy is performing an osteotomy at the center of the deformity to prevent abnormal joint line obliquity. If pathologic distal femoral varus deformity is the cause of genu varum, the osteotomy should be performed in the distal femur. Reports of medial opening wedge distal femoral osteotomy (DFO) to correct varus malalignment are rare. We present a case of this very rare and challenging condition in a 47-year-old male, which was successfully treated by medial opening wedge DFO.

Opening Wedge High Tibia Osteotomy / 대한정형외과학회잡지

Proximal tibial osteotomy is the preferred method for treating medial compartment knee arthritis with varus deformity. The purpose of this treatment is to reduce the weight burden of the lesion by correcting the mechanical axis of the patient with degenerative arthritis of medial tibiofemoral joint and abnormal alignment. In general, the proximal tibial osteotomy provides satisfactory clinical results when suitable patient are selected by considering the extent of cartilaginous injury and the age of the patient and the correct technique is performed. In tibial osteotomy, medial open wedge osteotomy is used widely because of its short operation time and relatively simple technique. This review describes the current knowledge of patient selection, preoperative evaluation and planning, treatment principles, surgical techniques, rehabilitation procedures and complications in open wedge high tibial osteotomy.

Basic Principles and Current Trends of Medial Opening-Wedge High Tibial Osteotomy / 대한정형외과학회잡지

High tibial osteotomy (HTO) is a popular surgical procedure for osteoarthritis of the knee with varus deformity. In general, HTO has shown sufficient clinical outcomes with careful patient selection and correct surgical technique. Among various surgical techniques, medial opening-wedge and lateral closing-wedge HTO are widely used. This report includes basic principles and current trends in patient selection and preoperative evaluations and planning, operative technique, complications, and rehabilitation protocol in medial opening-wedge HTO.

The stable upper tibial osteotomy for treatment of osteoarthritic knee (part III): The simplified medial opening step wedge technique.

This study reviews the simplified medial opening step wedge technique for upper tibial osteotomy by performing the operation without osteotomy of fibula and using narrow straight plate instead of T-plate fixation of the tibia. During 1991-1993, this simplified osteotomy technique was used in 19 patients 2 males and 19 females with age ranged 51-69 years old, whose 21 knees had degenerative varus osteoarthritic, 15 right and 6 left knees. Among these 19 patients, both joint debridement of the knees and the osteotomy were done in 2 patients suffered from osteoarthritic knees with excessive osteophytes near the joint surface. The result of 1-2 year follow up showed that the technique provided increased stability of osteotomy site, decreased postoperative swelling and pain during exercise and ragne of motion of the knees. Moreover, it could reduce the operative time. For the union of osteotomy, radiologic changing appearance of the knees and used the knees in daily activities were similar to the results of the treatment of osteoarthritic knees by technique of medial opening and lateral closing step wedge upper tibial soteotomy.