Open-wedge-Osteotomie: Konzept und erste Erfahrungen

Valgus high tibial osteotomy is an established treatment for medial osteoarthritis in the varus knee. The classic technique involves removal of a laterally based bone wedge from the tibia (closed wedge), fibula osteotomy and osteosynthesis of the tibia by a lateral exposure. This procedure has a certain risk potential regarding peroneal nerve injuries, instability of the osteotomy and secondary loss of correction. Opening wedge technique from medially avoids muscle detachment, dissection of the peroneal nerve, proximal fibula osteotomy and leg shortening. Only one osteotomy must be performed and the correction can be adapted intraoperatively. The posterior tibial slope can be adjusted as needed. A new specifically designed plate fixator inserted percutaneously allows stable fixation of the osteotomy. The use of bone grafts or bone substitutes can be avoided in most cases. 349 patients were treated with this technique. The mean opening of the osteotomies was 11,6 mm. Complications included 4 non-unions which required secondary bone grafting. However there were no implant failures nor any case of loss of correction. Hight tibial valgus osteotomy in opening wedge technique as shown above is a very safe and effective treatment method with minimal morbidity.     

Supplementary medial locking plate fixation of Ludloff osteotomy versus sole lag screw fixation: A biomechanical evaluation

BackgroundThe Ludloff oblique osteotomy is inherently unstable, which might lead to delayed union and loss of correction. Supplementary fixation to two lag screw fixation has been proposed. The hypothesis is that the osteotomy fixation constructs supplemented by a mini locking plate provide greater resistance to osteotomy gaping and loss of angular correction in response to cyclic loading.MethodsTwenty fourth generation composite 1st metatarsals were used and underwent a Ludloff osteotomy. They were divided in two fixation groups: two lag screws (Group A), and with a supplementary mini locking plate (Group B). Specimens were subjected to either monotonic loading up to failure or to fatigue (cyclic) tests and tracked using an optical system for 3D Digital Image Correlation.FindingsThe osteotomy gap increased in size under maximum loading and was significantly greater in Group A throughout the test. This increase was observed very early in the loading process (within the first 1000 cycles). The most important finding though, was that with the specimens completely unloaded the residual gap increase was significantly greater in Group A after only 5000 cycles of loading up to the completion of the test. The lateral angle change under maximum loading was also significantly greater in Group A throughout the test, with that increase observed early in the loading process (5000 cycles). With the specimens completely unloaded the residual lateral angle change was also significantly greater in Group A at the completion of the test.InterpretationSupplementary fixation with a mini locking plate of the Ludloff osteotomy provided greater resistance to osteotomy gaping and loss of angular correction compared to sole lag screws, in response to cyclic loading.     

Biomechanical investigation of different internal fixations in medial opening-wedge high tibial osteotomy

BACKGROUND: The medial opening-wedge osteotomy for treatment of varus gonarthritis has become very popular in recent years. Different implants for internal fixation after the osteotomy have been created. It is still unclear, which principle of internal fixation (angle stable or non-angle-stable plate with or without spacer) has the best biomechanical properties. The aim of this study was to determine the biomechanical properties of different fixation techniques in medial opening-wedge high tibial osteotomy in a porcine bone model. METHODS: A 10-mm high tibial opening-wedge osteotomy was performed and stabilized with plates of similar dimensions but different functional principle (conventional plate, angle stable plate with or without spacer). Biomechanical properties (stiffness, displacement within the osteotomy space and load at failure) were evaluated under axial load. RESULTS: Plates which contain a spacer had a significantly higher stiffness at a load at 1000 N (p < 0.05). This correlates with a significantly reduced deformation within the osteotomy space. The strength at failure was not different between the groups. The use of a spacer in a conventional plate produces fractures of the lateral tibial cortex. In angle stable plates and plates containing spacers, the failure was caused by fractures of the lateral tibia surface, the fibula or by displacement within the tibio-fibular joint. The failure was caused primarily by implant insufficiency in plates without spacers. CONCLUSIONS: In a model with comparable conditions, implants which contain a spacer have superior biomechanical properties. Angle stable plates may prevent fractures of the lateral cortex after opening-wedge osteotomy.     

Clinical and biomechanical aspects of external fixation of the pelvis

OBJECTIVE: The aim was to evaluate the mechanical stability of several traditional and modern external fixators in unstable pelvic ring disruption. DESIGN: In a laboratory study external and internal fixation techniques were tested in seven fresh and five embalmed human pelves with a disruption of the pubic symphysis and one sacroiliac joint (type C1.2 injury according to the Tile-AO classification). BACKGROUND: Stability provided by external fixation depends upon many factors, with the residual pelvic stability being the most important. METHODS: Simulating a single-leg stance, the load was applied quasi-statically to the acetabulum of the unstable hemipelvis. Device failure was defined as displacement >10 mm either at the symphysis pubis or the sacroiliac joint. RESULTS: The frame with the highest failure load (fresh versus embalmed specimens) was the Egbers configuration with the AO fixator (analysis of variance; P < 0.05). Failure was noted at 114.9 N versus 129.5 N. Augmentation of the Mono-Tube by additional internal posterior osteosynthesis gave the following results: sacral bars 325.4 N versus 217.8 N, plate fixation 294.3 N versus 215.8 N, lag screws 338.4 N versus 215.8 N. Failure loads of hybrid fixation of the Orthofix were as follows: sacral bars 257.9 N versus 213.9 N, plate fixation 333.5 N versus 245.3 N, lag screws 397.3 N versus 280.6 N. The differences between the two fixators were not statistically significant. CONCLUSIONS: No single external frame provided sufficient stability. The addition of a posterior internal fixation significantly increased failure loads and controlled the weight-bearing pelvic elements.     

Open wedge high tibial osteotomy: biomechanical investigation of the modified Arthrex Osteotomy Plate (Puddu Plate) and the TomoFix Plate

OBJECTIVE: To determine the biomechanical properties of different fixation methods for high tibial medial opening wedge osteotomy in order to determine appropriate surgical and rehabilitation guidelines. DESIGN: A biomechanical testing examined the construct stiffness and the fixation strength of two different plates. BACKGROUND: Although medial opening wedge techniques for high tibial osteotomies have become popular in recent years, biomechanical data of frequently used implants is lacking. METHODS: A 15-mm medial opening gap was stabilized in each of eight medium composite tibial bones either with the modified Arthrex Osteotomy Plate (Puddu Plate) or the TomoFix Plate. RESULTS: Both constructs failed under compression and torsion at the lateral cortex and occurred at higher maximal forces by using the TomoFix Plate. After fracture of the lateral cortex the axial stiffness was reduced by 47% and the torsional rigidity by 54% for the TomoFix. For the Puddu Plate these reductions were 66% and 78%, respectively. The differences between the two groups were significant in all conducted tests (P < 0.05). CONCLUSIONS: This study indicates that an unharmed lateral hinge largely dictates the stability after high tibial osteotomy. If the lateral cortex is injured, the TomoFix plate provides superior stability in both compression and torsion compared to the Puddu Plate. In the latter case additional fixation might be considered. RELEVANCE: These biomechanical tests helped to identify clinical situations in which the mechanical attributes of the plates would prove advantageous.     

Biomechanical comparison of screws and plates for hallux valgus opening-wedge and Ludloff osteotomies

BACKGROUND: The optimal osteotomy type and fixation method for hallux valgus correction have not been defined. This study examined the mechanical properties of corrective opening-wedge and Ludloff oblique osteotomies under conditions approximating postoperative weight-bearing. METHODS: Twenty-nine pairs of fresh-frozen metatarsals were divided into three groups. In Group 1, headless screws were compared with standard cortical screws for Ludloff osteotomy fixation. In Groups 2 and 3, Ludloff osteotomies fixed with headless screws were compared with opening-wedge osteotomies fixed with non-locking and locking plates, respectively. Constructs underwent dorsally-directed cantilever loading for 1000 cycles. FINDINGS: No significant differences in angulation or stiffness were demonstrable in Group 1. In Group 2, Ludloff/headless screw construct stiffness exceeded non-locking plate construct stiffness. The mean angulation on the 1000th load cycle was greater for plates than for Ludloff/headless screws. In Group 3, locking plate construct stiffness and angulation did not differ from Ludloff/headless screws in early cyclic loading, but fixation failure of the locking plate constructs was common. INTERPRETATION: The results indicate that screw type for Ludloff fixation may be left to surgeon preference and that opening-wedge plates exhibit mechanical properties inferior to that of the Ludloff osteotomy under the tested conditions. Lateral cortex continuity and bone density remain important factors in the performance of opening-wedge osteotomies.     

Internal fixation of radial neck fractures: an in vitro biomechanical analysis

OBJECTIVE: To assess the fixation rigidities of a custom designed blade plate, a 2.7 mm T-plate and 3.0 mm cannulated screws. DESIGN: A cadaveric non-comminuted radial neck fracture model was employed to test the three fixation methods, using a multi-directional shear loading protocol. BACKGROUND: The management of displaced radial neck fractures in adults remains unsatisfactory due to failure of internal fixation with secondary loss of reduction, and non-unions. METHODS: The stiffness of the various fixation methods was measured in five directions of loading in the transverse plane. Failure testing was performed on the final testing condition for each specimen, in a posteroulnar to anteroradial direction. RESULTS: The direction of specimen loading did not have a significant effect on the stiffness of the various methods of fixation (P = 0.4). There was no significant difference in the fixation stiffness between the 3.0 mm screws or blade plate, however, both were superior to the T-plate (P < 0.05). CONCLUSIONS: Although the 2.7 mm T-plate has been reported in the literature as a viable method of fixation for radial neck fractures, it may not be optimal from the viewpoint of fixation stability. In the setting of a non-comminuted radial neck fracture, the use of cross-cannulated screws or blade plate fixation is preferred.Relevance This study supports the use of cross-cannulated screws or blade plate fixation for non-comminuted fractures of the radial neck.     

Locked vs. unlocked plate osteosynthesis of the proximal humerus - a biomechanical study

BACKGROUND: Locked plates (internal fixators) have been found to be an optimal method for the fixation in proximal humeral fractures. In a biomechanical cadaver study the difference between locked and non-locked osteosyntheses was investigated. METHODS: Paired humeri were harvested, bone density measured. Locked internal fixators were mounted on one specimen; identical plate-screw-systems without locking mechanism applied to the contralateral specimen for comparison. After that, a transverse subcapital osteotomy was performed. With 7 pairs of humeri static tests with increasing axial loads and with 5 pairs dynamic tests with 10 N preload and 80 N maximal axial load for up to 1 million cycles were performed. RESULTS: In the static experiments the elastic stiffness of the construct was 74% higher in the locked group (median 80 N/mm, quartile range 77-86 N/mm) compared with the non-locked group (46 N/mm, 35.5-56.5 N/mm). The difference was statistically significant (Wilcoxon test for paired samples, P<0.05). Similarly, the linear range until failure was definitely extended in the locked group by 64% (92 N, 89-98 N vs. 56 N, 36.5-73.5 N, P<0.05). Under dynamic loading the non-locked group showed fixation failures between 97,000 and 500,000 cycles. In the locked group no failure was observed until the end of the experiment at 1 million cycles (P<0.0.5). The final deformation was found to be 1 mm (median, quartil range 1.0-1.2 mm) in the non-locked group and 0.3 mm (0.2-0.3 mm) in the locked group (P<0.05). The differences were found equally in lower as well as in higher bone density specimen. INTERPRETATION: Because of the optimal load transfer between implant and cancellous bone, a locked screw plate interface will reduce fixation failure in proximal humeral fractures.     

Biomechanical evaluation of different types of lateral hinge fractures in medial opening wedge high tibial osteotomy

BackgroundLateral hinge fractures are common complications in the medial opening wedge high tibial osteotomy for treatment of knee osteoarthritis. The rehabilitation protocols are decided depending on the remaining stability following these fractures. This study aimed to evaluate the biomechanical properties of different types of lateral hinge fractures in medial opening wedge high tibial osteotomy.MethodsTwenty synthetic tibia models were used as test samples. A 10-mm bone wedge was removed from the medial side of the proximal tibias to create the bone defect. The samples were then divided into 4 groups: (1) intact lateral hinge; (2) Takeuchi type I fractures; (3) type II fractures; and (4) type III fractures. After fixation with a locking plate, the stability parameters including construct stiffness, wedge displacement, and construct strength were tested under compressive forces and compared among the 4 groups.FindingsNo statistical difference was found in the construct stiffness among the 4 groups (P = 0.78). The type III fractures had the largest wedge displacement compared with the other 3 groups. The failure loads on average were significantly reduced in the type III fractures compared with those with intact hinge (P < 0.01) and in type I fractures (P = 0.04). No statistical difference was observed between the type I fractures and the intact hinge in terms of wedge displacement or failure loads.InterpretationThe type III fractures were the most unstable and patients with these fractures should be managed cautiously. Delayed weightbearing and/or additional fixation should be considered.     

多针内固定治疗跟骨骨折的有限元及临床分析

背景：选择恰当的治疗方法能明显改善跟骨关节内骨折患者的预后。目的：旨在分析跟骨骨折多针内固定和钢板内固定两种方法的固定效果,评价2种内固定方式的临床疗效。方法：①CT扫描正常男性右侧跟骨,建立完整跟骨三维有限元模型,模拟SandersⅡ型跟骨骨折,模拟跟骨骨折钢板和多针两种内固定后受到跟腱载荷的工况,对比研究钢板功能位0°、多针功能位0°组、多针跖屈30°组2种内固定3种分组模型的应力分布、骨折线相对位移和内固定最大主应力。②回顾性研究59例SandersⅡ型跟骨骨折,其中36例患足行切开复位多针内固定,23例患足行切开复位钢板内固定,采用Maryland足部评分系统评价跟骨骨折钢板和多针两种内固定后的临床疗效,并分析固定后软组织并发症。结果与结论：①有限元分析中加载足踝静止状态跟腱最大载荷160N,3组模型内固定的最大主应力值均小于内固定屈服强度225MPa。3组模型跟骨骨折线的相对移位均小于跟骨关节内骨折手术指征的骨折线分离或移位≥1mm的标准。连续加载1~1000N载荷的工况,3组模型内固定失效时对应的跟腱载荷均大于160N。模型的应力分布显示,多针与钢板内固定都均匀分布了应力。②临床研究结果显示SandersⅡ型骨折多针固定组优良率83%,钢板固定组优良率78%,两组固定后疗效差异无显著性意义（P〉0.05）,但多针固定组固定后软组织并发症发生率低于钢板固定组（P〈0.05）。     

不同内固定物治疗胫骨平台后内侧骨折的生物力学分析

背景：胫骨平台后内侧骨折的治疗较困难,容易出现因骨折固定方式选择不当导致骨折再次移位、骨不连、内固定失效及关节功能活动障碍等并发症。目的：分析3种胫骨平台后内侧骨折不同固定方法的生物力学效果。方法：27具新鲜骨标本,制成胫骨平台后内侧骨折模型,分别制成正常组,双钢板固定组,T形钢板固定组,拉力螺钉固定组。对以上3组进行压力、载荷一位移、应力强度、刚度和旋转性能测试。结果与结论：双钢板固定组载荷一位移显著小于T型钢板固定组和拉力螺钉固定组,双钢板固定组轴向刚度、水平剪切刚度及转矩扭角变化,均显著大于T型钢板固定组和拉力螺钉固定组。提示胫骨平台后内侧骨折双钢板固定较其他2种方法更具有生物力学上的稳定性。     

Adjustable-length loop cortical button versus interference screw fixation in quadriceps tendon anterior cruciate ligament reconstruction – A biomechanical in vitro study

BackgroundThis biomechanical cadaveric in vitro study aimed to evaluate and compare the dynamic elongation behavior and ultimate failure strength of tibial adjustable-length loop cortical button versus interference screw fixation in quadriceps tendon-based anterior cruciate ligament reconstruction.MethodsSixteen human quadriceps tendons were harvested and fixed into porcine tibiae using either biodegradable interference screw (n = 8) or adjustable loop device (n = 8) fixation. An acrylic block was utilized for femoral adjustable loop device fixation for both groups. All constructs were precycled for 10 times at 0.5 Hz and manually retensioned before tested in position and force control mode each for 1000 cycles at 0.75 Hz according to in vitro loading conditions replicating the in vivo ACL environment. Subsequently, an ultimate failure test at 50 mm/min was performed with mode of failure noted.FindingsTibial IS fixation showed no statistically significant differences in the initial (−0.46 vs. −0.47 mm; P = 0.9780), dynamic (2.18 mm vs. 2.89 mm; P = 0,0661), and total elongation (1.72 mm vs. 2.42 mm; P = 0,0997) compared to adjustable loop device fixation. The tibial button fixation revealed an increased ultimate failure load (743.3 N vs. 606.3 N; P = 0.0027), while stiffness was decreased in comparison to screw fixation (133.2 N/mm vs. 153.5 N/mm; P = 0,0045).InterpretationAnterior cruciate ligament reconstruction for quadriceps tendon graft using a tibial adjustable-length loop cortical button provides for comparable dynamic stabilization of the knee with increased ultimate failure load at decreased stiffness compared to screw fixation.     

三种固定器械固定胫骨骨折的应力松弛实验

背景：骨力学是生物力学的分支,研究内外固定器固定骨折后的生物力学特性是评价固定效果的重要方法之一。目的：比较3种内外固定器械固定胫骨骨折后骨的应力松弛特性。方法：模拟胫骨骨折分别以髓内钉,钢板,外固定支架进行固定。在电子万能试验机上对3组标本进行轴向压缩应力松弛实验。结果与结论：从各组内、外固定标本轴向压缩应力松弛曲线可以看出,外固定支架组7200s应力松弛量大于钢板和髓内钉组,但差异无显著性意义（P〉0.05）。初步表明股骨颈骨折钢板固定、髓内钉固定、外固定支架固定后对骨的应力松弛特性影响基本一致。     

Effects of screw types in cementless fixation of tibial tray implants: stability and strength assessment

OBJECTIVE: To test the stability and strength of tibial trays fixed with cortical screws and tibial trays fixed with cancellous screws under axial and anterior-posterior shear loading conditions. DESIGN: Five matched human fresh frozen cadaver knees without prior pathology were used as paired specimens for comparison of cortical to cancellous screw fixation of tibial trays. BACKGROUND: Current cementless fixation of tibial trays in total knee arthroplasty is obtained by using a combination of stems, keels, posts, pegs, and screws. To date there has been no study comparing isolated cortical and cancellous screw fixation in cementless arthroplasty. METHODS: An Instron machine and a video digitizing system were used to examine tibial tray lift-off, subsidence, and anterior-posterior load to failure at the bone-implant interface in five matched pairs of knees and compare the difference between cancellous and cortical screw fixation. RESULTS: Non-destructive cyclic testing showed a significant difference between the two types of screws for tibial tray subsidence with cancellous fixation greater than cortical (P < 0.05), but not for lift-off (P > 0.05). Load to failure testing in anterior-posterior direction did not result in a significant difference between the two types of screws for initial stiffness and ultimate load (P > 0.05), but did result in a significant difference of energy absorbed to failure (P < 0.01). CONCLUSIONS: The difference in amount of subsidence between cortical and cancellous fixation could possibly be due to microfractures of the underlying trabecular bone with cancellous fixation. Neither screw type was able to completely fix the tibial tray to bone and prevent micromotion. Although the load at failure for anterior-posterior shear was similar for the two screw types, the energy absorbed was greater for the cortical screws which may be a result of additional strength provided by the cortical bone surrounding the screw.     

Intramedullary nailing vs. palmar locked plating for unstable dorsally comminuted distal radius fractures: A biomechanical study

BackgroundThe purpose of this study was to compare the stability of a 2.4 mm palmar locking compression plate and a new intramedullary nail-plate-hybrid Targon DR for dorsally comminuted distal radius fractures.MethodsAn extraarticular 10 mm dorsally open wedge osteotomy was created in 8 pairs of fresh frozen human radii to simulate an AO–A3-fracture. The fractures were stabilized using one of the fixation methods. The specimens were loaded axially with 200 N and dorsal-excentrically with 80 N. 2000 cycles of dynamic loading and axial loading-to-failure were performed.FindingsAxial loading revealed that intramedullary osteosynthesis (Targon DR: 369 N/mm) was significantly (p = 0.017) stiffer than plate osteosynthesis (Locking compression plate: 131 N/mm). With 214 N/mm the intramedullary nail also showed higher stability during dorsal excentric loading than the Locking compression plate with 51 N/mm (p = 0.012). After 2000 cycles of axial loading with 80 N the Targon DR-group was significantly stiffer than the Locking compression plate-group under both loading patterns. Neither group showed significant changes in stiffness after 2000 cycles. Under dorsal excentric loading the Targon DR-group was still significantly stiffer with 212 N/mm than the Locking compression plate-group with 45 N/mm (p = 0.012). The load to failure tests demonstrated higher stability of intramedullary nailing (625 N) when compared to plate osteosynthesis (403 N) (p < 0.025).InterpretationThe study shows that intramedullary fixation of a distal AO–A3 radial fracture is biomechanically more stable than volar fixed-angle plating under axial and dorsal-excentric loading in an experimental setup.     

胫骨平台后外侧骨折3种内固定方式的有限元分析

背景：如今胫骨平台骨折的研究已由起初的内外侧＂双轨道结构＂逐步转型为＂360°全方位立体结构＂,国内外学者们更关注平台后侧结构的稳定性、复位情况以及对复位后功能恢复的影响。后侧平台的内固定材料的选择仍无明确定论,存在较大争议。目的：探讨胫骨平台后外侧骨折3种内固定方式的生物力学特性。方法：通过计算机三维有限元技术,模拟胫骨平台后外侧1/2和后外侧1/4骨折。分别使用前侧2枚6.5 mm拉力螺钉、外侧4.5 mm L型钢板以及后侧3.5 mm T型钢板置入内固定骨折块。在胫骨平台中心处加载500 N纵向应力,比较3种内固定方式的生物力学状态。结果与结论：在1/2骨块模型中,前侧拉力螺钉与后侧钢板在各个方向上的位移较小,外侧钢板的位移较其他两种固定方式大。而在1/4骨块模型中,前侧拉力螺钉在各方向的位移优势更明显,后侧钢板的位移居次,外侧钢板的位移最大。1/2骨块上,前侧拉力螺钉的最大应力为36.523 MPa,外侧钢板为153.372 MPa,后侧钢板为115.922 MPa;而在骨块上的最大应力前侧拉力螺钉模型为4.309 MPa,外侧钢板为4.37 MPa,后侧钢板为3.124 MPa。1/4骨块上前侧拉力螺钉的最大应力为36.803 MPa,外侧钢板为153.336 MPa,后侧钢板为104.234 MPa;而在骨块上的最大应力前侧拉力螺钉模型为1.195 MPa,外侧钢板为0.827 MPa,后侧钢板为1.196 MPa。提示前侧拉力螺钉能够承担更大的应力,并在受到应力后位移变化较小,可提供较稳定的支持。而后侧钢板在骨块较大（1/2骨块）时,能够提供较强的稳定性,与拉力螺钉相仿;而在骨块较小（1/4骨块）时,稳定性不如前侧拉力螺钉。外侧钢板在固定胫骨平台后外侧骨折时,稳定性较差,不如前侧拉力螺钉和后侧钢板。     

Fixed-angle plate osteosynthesis of the patella – An alternative to tension wiring?

Background

The goal of this study is carry out a biomechanical evaluation of the stability of a bilateral, polyaxial, fixed-angle 2.7 mm plate system specifically designed for use on the patella. The results of this approach are then compared to the two currently most commonly used surgical techniques for patella fractures: modified anterior tension wiring with K-wires and cannulated lag screws with anterior tension wiring.

Methods

A transient biomechanical analysis determining material failure points of all osteosyntheses were conducted on 21 identical left polyurethane foam patellae, which were osteotomized horizontally. Evaluated were load (N), displacement (mm) and run-time (s) as well as elastic modulus (MPa), tensile strength (MPa) and strain at failure (%).

Findings

With a maximum load capacity of 2396 (SD 492) N, the fixed-angle plate proved to be significantly stronger than the cannulated lag screws with anterior tension wiring (1015 (SD 246) N) and the modified anterior tension wiring (625 (SD 84.9) N). The fixed-angle plate displayed significantly greater stiffness and lower fracture gap dehiscence than the other osteosyntheses. Additionally, osteosynthesis deformation was found to be lower for the fixed-angle plate.

Interpretation

A bilateral fixed-angle plate was the most rigid and stable osteosynthesis for horizontal patella fractures with the least amount of fracture gap dehiscence. Further biomechanical trials performed under cycling loading with fresh cadaver specimen should be done to figure out if a fixed-angle plate may be an alternative in the surgical treatment of patella fractures.     

微创与切开复位钢板内固定修复胫骨远端骨折的比较

背景：近年来微创经皮钢板置入内固定技术已成为修复下肢骨折尤其是下肢复杂型骨折一种可选择的方法,其优势就在于可减少对软组织的损伤,不破坏骨质的营养供应血管。但目前对于修复胫骨远端骨折采用何种方法仍没有统一标准。目的：对比观察微创经皮钢板置入内固定和切开复位钢板置入内固定修复胫骨远端骨折的临床效果。方法：纳入60例胫骨远端骨折的病例,其中35例接受微创经皮钢板置入内固定治疗,25例患者接受切开复位钢板置入内固定治疗。通过对软组织进行评分来确定明确的手术时间,术中注意对骨折处软组织的保护并选择合理的方式进行内固定。内固定后指导患者积极的进行早期功能锻炼。临床随访,定期进行X射线复查。通过观察手术时间、患肢负重时间、骨折愈合时间、胫骨功能恢复等指标对比两种内固定方式的临床疗效。结果与结论：所有患者内固定后均得到随访,随访时间3-15个月。微创经皮钢板置入内固定组在治疗 A 型骨折的愈合时间方面与切开复位钢板置入内固定组没有明显差异,B、C型骨折愈合时间优于后者。提示应用微创经皮钢板置入内固定修复胫骨骨折,尤其是胫骨远端复杂型骨折,是一种有效的治疗方法。骨折愈合率高,术后并发症少。     

Biomechanical comparison of two side plate fixation techniques in an unstable intertrochanteric osteotomy model: Sliding Hip Screw and Percutaneous Compression Plate

BACKGROUND: Our objective was to determine the biomechanical primary stability of two different side plate fixation devices in an unstable intertrochanteric cadaver model: the Sliding Hip Screw with an additional derotation screw was compared with the Percutaneous Compression Plate. METHODS: Eight pairs of human cadaver femurs were tested for comparison of the primary stability of the two implants in two modes: (a) cyclic loading up to 200 N, 400 N, 600 N, 800 N, and 1000 N, respectively. In vitro combined axial and bending loads were applied. Angular displacements of the proximal head fragment during loading were recorded in rotational, varus-valgus, and anterior-posterior directions. (b) The load to failure was determined. FINDINGS: Specimens fixed with the Percutaneous Compression Plate showed higher displacements in the varus during loading up to 200 N (P=0.033), and 400 N (P=0.001), compared to the Sliding Hip Screw. A similar tendency was observed for higher loads. The Percutaneous Compression Plate allowed more external rotation of the proximal fragment only at loads up to 800 N (P=0.019). No statistical difference could be found for the slight migrations in the posterior direction. Load to failure also revealed no statistical difference between the two implants. INTERPRETATION: The Percutaneous Compression Plate as a double-axis fixation device with a sliding capability allows higher displacements in the varus direction and also in external rotation at 800 N loading compared to the Sliding Hip Screw as a single-axis fixation device combined with an additional derotation screw. While both implants are successful used in clinical practice, this should be considered in treatment of unstable intertrochanteric fractures with inferior comminution in osteoporotic patients.