ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
Introduction: Unidirectional porous β-tricalcium phosphate (UDPTCP) consists of a novel porous artificial bone that is structurally different from conventional artificial bone comprised of spherical porous β-tricalcium phosphate (SPTCP).Case presentation: We present our first four clinical cases of opening-wedge high tibial osteotomy (OWHTO) using UDPTCP and SPTCP together. The patients’ mean age was 54.5 ± 5.9 years, and the mean observation period was 20.8 ± 2.8 months. In OWHTO, two wedge shaped pieces of UDPTCP and SPTCP were cut to fit the gap and implanted parallel to each other in the anterior and posterior parts, respectively. We evaluated the correction loss and bone remodeling for UDPTCP and SPTCP over time using radiography and computed tomography, and evaluated the clinical outcomes.Conclusion: There was no correction loss reported in any case, and early bone remodeling was observed with UDPTCP. All patients achieved satisfactory clinical results with no adverse events.
ABSTRACT
Objective: To summarize the management principle and clinical suggestions of the osteotomy gap of opening wedge high tibial osteotomy (OWHTO). Methods: The related literature of the osteotomy gap of OWHTO in recent years was reviewed, summarized, and analyzed. Results: Delayed union and non-union of the osteotomy gap are main complications of OWHTO. Tomofix plate, as locking steel plate, has the characteristics of angular stability and can better maintain the stability of the osteotomy gap, promote bone healing, and avoid loss of correction. There are some treatment options for the osteotomy gap site, such as, without bone, autologous bone graft, allogeneic bone graft, bone substitute materials graft, and augment factor graft to enhance bone healing. When the osteotomy gap is less than 10 mm, it achieves a good outcome without bone graft. For the obesity, lateral hinge fracture, large osteotomy gap, or correction angle more than 10°, the bone graft should be considered. In cases whose osteotomy gap is nonunion or delayed union, the autologous bone graft is still the gold standard. When the osteotomy gap repaired with the allogeneic bone graft, it is better to choose fragmented cancellous or wedge-shaped cancellous bone, combining with the locking plate technology, also can achieve better bone union. The bone substitute material of calcium-phosphorus is used in the osteotomy gap, which has the characteristics of excellent bone conduction, good biocompatibility, and resorption, combining with the locking plate technology, which can also achieve better bone union in the osteotomy gap. The augment factors enhance the bone healing of the osteotomy gap of OWHTO is still questionable. The bone union of the osteotomy gap is also related to the size of the osteotomy gap and whether the lateral hinge is broken or not. Conclusion: No matter what type of materials for the osteotomy gap, OWHTO can improve the function and relieve pain for knee osteoarthritis. More randomized controlled trials are needed to provide evidence for clinical decision to determine which treatment option is better for the osteotomy gap of OWHTO.
ABSTRACT
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.
ABSTRACT
PURPOSE: The aim of this study is to compare the clinical results and radiologic changes of closing-wedge high tibial osteotomy (CW HTO) and opening-wedge high tibial osteotomy (OW HTO). MATERIALS AND METHODS: Seventy five knees were treated with a CW HTO and 41 with an OW HTO. For each patient the hip-knee-ankle (H-K-A) axis was evaluated and the degree of the medial compartmental arthrosis was measured by Ahlback-type radiological classification. The function of the knee was evaluated by the Tegner activity score, the Lysholm knee scoring scale and the Western Ontario and McMaster University index. Lateral radiographs were taken to assess the patellar height and the posterior tibial inclination. RESULTS: In both groups significant improvement of the visual analogue scale and range of motion was achieved. The frontal plane H-K-A axis was corrected significantly from varus to the range of physiological valgus and the arthrosis of the medial compartment of the knee progressed gradually. The body mass index was significantly influential to the progression of arthrosis. The functions of the knee were improved significantly in all cases. In the closing-wedge group, the patella height was increased at the postoperative period, while it was decreased in the opening-wedge group. There was a tendency of a decrease of the tibial inclination in the CW HTO group and a statistically significant increase of the tibial inclination in the OW HTO group. Recurrence of varus occurred in sixteen cases. CONCLUSION: In both groups, improvement of the function of the knee was achieved, but there was no statistical difference. However, the opposite result was found in the patella height and the tibial inclination.