BACKGROUND: The purpose of this study was to analyze biomechanical properties of a novel wedge locking plate in medial open wedge high tibial osteotomy (OWHTO) in a porcine tibial model. METHODS: A uniform 8-mm OWHTO was performed in 12 porcine tibiae. Six of them were subsequently fixed with the plate without a wedge, whereas the other 6 were additionally reinforced with a metal wedge of 8 mm. Biomechanical properties (stiffness, displacement of the osteotomy gap, and failure load) were evaluated under axial load. The different modes of failure were also investigated. RESULTS: The plate showed an axial stiffness of 2,457 ± 450 N/mm with a wedge and 1,969 ± 874 N/mm without a wedge. The maximum failure load was 5,380 ± 952 N with a wedge and 4,354 ± 607 N without a wedge. The plate with a wedge had a significantly greater failure load and significantly less displacement of medial gap at failure than that without a wedge (p = 0.041 and p = 0.002, respectively). The axial stiffness was not different between the two types of fixation. Most failures were caused by lateral cortex breakage and there was no implant failure. CONCLUSIONS: The novel wedge locking plate showed excellent biomechanical properties and an additional wedge provided significant improvement. This plate can be a good fixation method for OWHTO.
Knee ; Methods ; Osteotomy ; Tibia

Malunion causes not only cosmetic problems, but also degenerative osteoarthritis due to changes in the anatomical and mechanical axes. Corrective osteotomy may be required in some cases to prevent these complications. The corrective osteotomy is divided into two types: Straight and dome. The straight type is divided into open and closed wedge, in accordance with the correction method. Surgeons should understand the indication, surgical procedure, as well as the advantages and disadvantages of each osteotomy method. Deciding on the method of corrective osteotomy depends on the degree of angulation, soft tissue condition, approximate with joint, implant type, and the experience of the surgeon.
Joints ; Methods ; Osteoarthritis ; Osteotomy* ; Surgeons

Humans ; Osteotomy ; adverse effects ; methods ; Scoliosis ; surgery

Humans ; Osteotomy ; adverse effects ; methods ; Scoliosis ; surgery

The purpose of this study was to investigate that there was any differences of uptake ratio of Tc99-m-MDP during the healing process related to fracture level in tibia. Thirty mature rabbits were devided into three groups and each group consisted of ten rabbits. The osteotomy was performed at the proximal third of tibia in group I, at the middle third in group II and at the distal third in group III, respectively. After fracture was reduced, the fractured tibia was fixed with K-wire and immobilized with long leg cast. Serial Tc-99m-MDP scintigraphy with pixel counting method was performed in thirty cases of tibial shaft fracture from one day to eight weeks after fracture. The results obtained were as follows: l. In group I, the mean uptake ratio of Tc-99m-MDP at fracture site was 1.40±0.45 at two days after fracture, 3.34±1.21 at two weeks and increased rapidly to a maximal value of 7.51%1.01 at three weeks and decreased thereafter to 4.530.83 at eight weeks. 2. In group II, the mean uptake ratio was 1.10±0.10 at three days, 3.931.±10 at three weeks and increased rapidly to a maximal value of 7.37±2.21 at four weeks and decreased thereafter to 4.54±0.96 at eight weeks. 3. In group III, the mean uptake ratio was 1.13 ± 0.11 at three days, 3.95±0.93 at three weeks and increased rapidly to a maximal value of 7.43±1.72 at four weeks and decreased thereafter to 4.69±0.93 at eight weeks. These experiments suggest that the changes of Tc-99m-MDP scintigraphy in the proximal third fractures of tibia was earlier than middle or distal third fractures and there was no differences between middle and distal third fractures of the tibia.
Leg ; Methods ; Osteotomy ; Rabbits ; Radionuclide Imaging ; Tibia

How to remove the well fixed cement or cementless prosthesis and get a completely distal cement removal in the rTHR are critical to the outcome of revision. Because of higher rate of union, excellent intraoperative exposure, and adjustment of abductor tension, ETO has been widely applied to rTHR and complicated primary THR by foreign scholars. Furthermore, this technology has wide indications, very few contraindications, high cure rates,and low complications rate. ETO turns out to be a safe and effective revision technology. In the article, the indication, contraindication, complications and advantages of this technique were reviewed.
Arthroplasty, Replacement, Hip ; methods ; Humans ; Osteotomy ; adverse effects ; methods

OBJECTIVETo investigate the method for mandible osteotomy in order to make the mandible of various square face appear harmony.

METHODSAccording to different types of the mandible, mandible angle osteotomy was performed in combination with mandible edge, mandible half ring osteotomy or chin augmentation.

RESULTSA total of 312 cases have been treated since 1996. In this series, mandible angle and mandible edge osteotomy was performed in 200 cases; only mandible edge osteotomy in 23; mandible half ring osteotomy in 15, chin sharpening in 9, chin augmentation with autogenous bone implantation, in 32. Postoperative follow-up of 150 cases for 1-12 months showed that the satisfactory rate was 97%.

CONCLUSIONIntegrated mandible osteotomy can make the square face look natural and nice-looking.

OBJECTIVES: The aim of this study was to compare the mechanical resistance of four different osteosyntheses modeled in two different sagittal split ramus osteotomy (SSRO) designs and to determine the linear loading in a universal testing machine. MATERIALS AND METHODS: An in vitro experiment was conducted with 40 polyurethane hemimandibles. The samples were divided into two groups based on osteotomy design; Group I, right angles between osteotomies and Group II, no right angles between osteotomies. In each group, the hemimandibles were distributed into four subgroups according to the osteosynthesis method, using one 4-hole 2.0 mm conventional or locking plate, with or without one bicortical screw with a length of 12.0 mm (hybrid technique). Each subgroup contained five samples and was subjected to a linear loading test in a universal testing machine. RESULTS: The peak load and peak displacement were compared for statistical significance using PASW Statistics 18.0 (IBM Co., USA). In general, there was no difference between the peak load and peak displacement related to osteotomy design. However, when the subgroups were compared, the osteotomy without right angles offered higher mechanical resistance when one conventional or locking 2.0 mm plate was used. One locking plate with one bicortical screw showed higher mechanical resistance (162.72±42.55 N), and these results were statistically significantly compared to one conventional plate with monocortical screws (P=0.016) and one locking plate with monocortical screws (P=0.012). The difference in peak displacement was not statistically significant based on osteotomy design or internal fixation system configuration. CONCLUSION: The placement of one bicortical screw in the distal region promoted better stabilization of SSRO. The osteotomy design did not influence the mechanical behavior of SSRO when the hybrid technique was applied.
In Vitro Techniques ; Jaw Fixation Techniques ; Methods ; Orthognathic Surgery ; Osteotomy ; Osteotomy, Sagittal Split Ramus* ; Polyurethanes

Humans ; Osteotomy ; methods ; Spinal Diseases ; surgery ; Treatment Outcome

BACKGROUND: Fixation of proximal chevron metatarsal osteotomy has been accomplished using K-wires traditionally and with a locking plate recently. However, both methods have many disadvantages. Hence, we developed an intramedullary fixation technique using headless cannulated screws and conducted a biomechanical study to evaluate the superiority of the technique to K-wire and locking plate fixations. METHODS: Proximal chevron metatarsal osteotomy was performed on 30 synthetic metatarsal models using three fixation techniques. Specimens in group I were fixated with K-wires (1.6 mm × 2) and in group II with headless cannulated screws (3.0 mm × 2) distally through the intramedullary canal. Specimens in group III were fixated with a locking X-shaped plate (1.3-mm thick) and screws (2.5 mm × 4). Eight metatarsal specimens were selected from each group for walking fatigue test. Bending stiffness and dorsal angulation were measured by 1,000 repetitions of a cantilever bending protocol in a plantar to dorsal direction. The remaining two samples from each group were subjected to 5 mm per minute axial loading to assess the maximal loading tolerance. RESULTS: All samples in group I failed walking fatigue test while group II and group III tolerated the walking fatigue test. Group II showed greater resistance to bending force and smaller dorsal angulation than group III (p = 0.001). On the axial loading test, group I and group II demonstrated superior maximum tolerance to group III (54.8 N vs. 47.2 N vs. 28.3 N). CONCLUSIONS: Authors have demonstrated proximal chevron metatarsal osteotomy with intramedullary screw fixation provides superior biomechanical stability to locking plate and K-wire fixations. The new technique using intramedullary screw fixation can offer robust fixation and may lead to better outcomes in surgical treatment of hallux valgus.
Fatigue ; Hallux Valgus* ; Hallux* ; Metatarsal Bones* ; Methods* ; Osteotomy* ; Walking