Objective To compare the biomechanical stability of Kirschner wire and tension band wiring, reconstruction plate combined with tension band wiring, and olecranon anatomical plate in fixing proximal ulna combined with olecranon fracture, so as to provide the theoretical evidence for clinical selection of internal fixation. Methods Eight specimens of elbow joints and ligaments were taken from eight fresh male adult cadaveric elbows (aged 26-43 years, mean 34.8 years) donated voluntarily. The model of proximal ulna combined with olecranon fracture was made by an osteotomy in each specimen. Fracture end was fixed successively by Kirschner wire and tension band wiring (group A), reconstruction plate combined with tension band wiring (group B), and olecranon anatomical plate (group C), respectively. The biomechanical test was performed for monopodium compression experiments, and load-displacement curves were obtained. The stability of the fixation was evaluated according to the load value when the compression displacement of fracture segment was 2 mm. Results No Kirschner wire withdrawal, broken plate and screw, loosening and specimens destruction were observed. The load-displacement curves of 3 groups showed that the displacement increased gradually with increasing load, while the curve slope of groups B and C was significantly higher than that of group A. When the compression displacement was 2 mm, the load values of groups A, B, and C were (218.6 ± 66.9), (560.3 ± 116.1), and (577.2 ± 137.6) N, respectively; the load values of groups B and C were significantly higher than that of group A (P lt; 0.05), but no significant difference was observed between groups B and C (t=0.305, P=0.763). Conclusion The proximal ulna combined with olecranon fracture is unstable. Reconstruction plate combined with tension band wiring and olecranon anatomical plate can meet the requirement of fracture fixation, so they are favorable options for proximal ulna combined with olecranon fracture. Kirschner wire and tension band wiring is not a stable fixation, therefore, it should not be only used for proximal ulna combined with olecranon fracture.
To evaluate the biomechanical action of lateral malleolar’s anatomical hook-plate in treatingWeber A-type ankle fracture. Methods Forty-eight cadaveric specimens of adult’s inferior extremities from June 2005to October 2006 were observed, consisting of 26 males and 22 females and aged 18-55 years. The external malleolus of the specimens were transected by using a wire saw at the ankle joint level, and then were divided into 4 groups randomly (groups A, B, C and D). Four distinct internal fixation instruments were used: lateral malleolar’s anatomical hook-plate in group A, general screws in group B , 1/3 tubular plate in group C and standard tension band in group D. Each group was further divided into 2 subgroups, A1-D1 and A2-D2. A1-D1 groups underwent anti-pressure and A2-D2 groups underwent anti-torsion biomechanically comparative analysis. Results The peak values of anti-pressure experiments in groups A1-D1 were (799.83 ± 105.47), (699.17 ± 63.81), (598.83 ± 123.14) and (453.00 ± 111.67) N respectively, group A1 was significantly higher than groups B1, C1 and D1 (P lt; 0.01); meanwhile, the peak values of anti-torsion experiments in groups A2-D2 were (37.17 ± 1.81), (30.33 ± 2.22), (20.50 ± 2.92), (24.83 ± 3.47) Nm respectively, group A2 was significantly higher than groups B2, C2 and D2 (P lt; 0.01). Conclusion The lateral malleolar’s anatomical hook-plate represents a definite biomechanical superiority, when compared with other 3 internal fixation instruments in treating fracture of external mlleolus.
ObjectiveTo investigate the effectiveness of open reduction and internal fixation with locking anatomical plate for treating valgus impacted proximal humerus fracture. MethodsA retrospective analysis was made on the clinical data of 38 patients with valgus impacted proximal humerus fracture who underwent open reduction and internal fixation with locking anatomical plate between January 2009 and January 2014. There were 25 males and 13 females, aged from 47 to 63 years (mean, 52.3 years); the left and the right sides were involved in 18 and 20 cases, respectively. The causes of fracture included high falling injury in 10 cases, traffic accident injury in 15 cases, and falling injury in 13 cases. The time between injury and operation was 5-10 days (mean, 7.5 days). The collodiaphyseal angle was 160-200° (mean, 176°) on X-ray films. ResultsAll incisions healed by first intention, and there was no early complication related to operation. All these patients were followed up 12-30 months (mean, 18 months). X-ray film showed that clinical healing time of fracture was 10-16 weeks after operation (mean, 12 weeks); at 12 months after operation, the collodiaphyseal angle recovered to 120-145° (mean, 135°). During follow-up, no loss of fracture reduction and no loosening of internal fixation were observed. At 10-12 months, osteonecrosis of the humeral head occurred in 3 cases (7.9%), including 2 cases of Cruess stageⅢand 1 case of Cruess stageⅣ. At last follow-up, the Constant shoulder joint scores were 56-95 (mean, 82.6); the results were excellent in 10 cases, good in 15 cases, fair in 9 cases, and poor in 4 cases, with an excellent and good rate of 66%. Visual analogue scale (VAS) scores were 0-6 (mean, 0.9). ConclusionIt can achieve a comparatively satisfactory clinical result to use open reduction and internal fixation with locking anatomical plate for treating valgus impacted proximal humerus fracture.
Objective To develop an anatomical locking plate in accordance with the anatomical characteristics of the sternoclavicular joint, which is reliable fixation and easy to operate, so as to provide an ideal internal fixation device for the treatment of sternoclavicular joint dislocation or peripheral fractures. Methods Gross measurement and CT measurement were performed on the 8 adult antiseptic and moist cadaver specimens (16 sides) to measure the parameters of surrounding bone structure of the sternoclavicular joint. The parameters included the thickness of presternum, sternal notch width, anteroposterior diameter of proximal 1/3 of clavicle, upper and lower diameters of proximal 1/3 of clavicle, angle between proximal end of clavicle and presternum in coronal plane, and angle of thoracoclavicular joint at anatomic position forward. According to the anatomical parameters and biomechanical properties of the specimens, the anatomical locking plate was designed and developed. The sternoclavicular ligament and joint capsule of all the specimens were completely cut off to make the sternoclavicular joint dislocation model. The left and right sternoclavicular joint of each specimen were randomly divided into experimental group (anatomic locking plate fixation) and control group (oblique T shape locking plate fixation). The sternoclavicular joint activity and common force mechanism was simulated on the universal mechanical testing machine, and the clavicular distal load test, sternoclavicular joint torsion test, and anti-pulling of steel plate manubrium part test were performed. Results The differences between the anatomical parameters of gross measurement and CT measurement were not significant (P>0.05). In the clavicular distal load test, when the anatomical position perpendicular to the distal clavicle back loading to 20 N, the displacement of loading point in the experimental group was (8.455±0.981) mm, which was significantly less than that in control group [(10.163±1.379) mm] (t=–3.012,P=0.020); the distal clavicle displacement of loading point of experimental group and control group were (5.427±1.154) mm and (6.393±1.040) mm, respectively, showing no significant difference (t=–1.459, P=0.188). In the sternoclavicular joint torsion test, the torque of experimental group was significantly greater than that of control group when the clockwise torsion angle was at 2, 4, 6, 8, and 10 degrees and the counterclockwise torsion angle was at 4, 6, 8, and 10 degrees (P<0.05). The torsional stiffness in the experimental group under clockwise and counterclockwise condition was 0.122 and 0.108 N·m/° respectively, which were significantly higher than those in the control group (0.083 and 0.078 N·m/° respectively) (F=67.824, P=0.000; F=20.992, P=0.002). In the anti-pulling of steel plate manubrium part test, the maximum pullout force of experimental group [(225.24±16.02) N] was significantly higher than that in control group [(174.40±21.90) N] (t=5.785, P=0.001). Conclusion The new type of anatomical locking plate can realize the sternoclavicular joint three-dimensional fixation, and has the advantages of reliable fixation, simple operation, less trauma, superior biomechanical properties, and earlier functional exercise. It may be an ideal internal fixation device in clinical treatment of sternoclavicular joint dislocation or peripheral fractures.
Objective To investigate the effectiveness of a new tibial plateau posterolateral column universal locking anatomical plate (hereinafter referred to as “new universal locking anatomical plate”) in the treatment of tibial plateau posterolateral column fractures. Methods Between October 2020 and December 2021, 14 patients with tibial plateau posterolateral column fracture were treated with a new universal locking anatomical plate. There were 7 males and 7 females with an average age of 59 years ranging from 29 to 75 years. There were 5 cases on the left side and 9 cases on the right side. The causes of injury included falling from height in 5 cases, traffic accident in 7 cases, and other injuries in 2 cases. The time from injury to operation ranged from 3 to 10 days, with an average of 6 days. According to Schatzker classification, there were 4 cases of type Ⅱ, 8 cases of type Ⅴ, and 2 cases of type Ⅵ. All fractures involved the posterolateral tibial plateau. Three column classification: two columns (anterolateral column+posterior column) in 4 cases, three columns in 10 cases. The operation time, intraoperative blood loss, fracture healing, and complications were recorded. The reduction of tibial plateau fracture was evaluated by Rasmussen radiographic score, and the recovery of knee function was evaluated by Hospital for Special Surgery (HSS) score. Results All 14 cases completed the operation successfully. The operation time was 95-180 minutes, with an average of 154 minutes, and the intraoperative blood loss was 100-480 mL, with an average of 260 mL. All patients were followed up 6-19 months, with an average of 12.5 months. All fractures healed, and the healing time was 15-24 weeks, with an average of 18.7 weeks. During the follow-up, there was 1 case of common peroneal nerve palsy and 1 case of traumatic osteoarthritis. There was no other complication such as vascular injury, incision infection, deep venous thrombosis of lower limbs, heterotopic ossification, bone nonunion, and failure of internal fixation. The reduction of tibial plateau fractures was good immediately after operation, and the Rasmussen radiological score was 10-18, with an average of 15.7; 3 cases were excellent, 10 cases were good, and 1 case was fair, with an excellent and good rate of 92.9%. The scores and grades of HSS at 3 months after operation and at last follow-up significantly improved when compared with those before operation (P<0.05). There was no significant difference between 3 months after operation and last follow-up (P>0.05).Conclusion For the fractures involving the posterolateral column of the tibial plateau, the new universal locking anatomical plate can provide strong fixation, satisfactory postoperative fracture reduction, and good recovery of knee function.