Tensile strength of bone fixation of hydroxyapatite coated Schanz screws of the Heidelberg External Fixation System (HEFS)--comparative torque measurements in clinical use and in cadaver tibia]

It is claimed in the literature that hydroxyapatite(HA)-coated screws of external fixators have superior fixation strength in bone, which is postulated to lead to a substantial decrease in loosening and infection rates. We report on a study of the maximum torque values developed while inserting and removing 30 HA-coated Schanz screws of 8 Heidelberg external fixation systems applied to the tibia to correct leg length differences and axial deformities. The infection rate was determined in accordance with defined criteria, and was found to be about 20% for the HA-coated screws. Screws without infection showed an extraction torque above insertion torque, screws with infection an extraction torque below. A significant correlation (p = 0.05) was seen between infection and decrease in fixation strength (quotient: loosening torque/tightening torque). To exclude the impact of such biological processes as osteointegration and bone remodelling, the clinical results were compared with the torques measured for coated and uncoated Schanz screws in a human cadaveric tibia. A significantly higher fixation strength in bone was found for HA-coated screws in comparison with uncoated screws (p = 0.002). These data warrant a clinical study directly comparing HA-coated and uncoated Schanz screws.     

对侧皮质锁定螺钉与锁定螺钉治疗股骨远端骨折疗效比较

目的:比较对侧皮质锁定螺钉与锁定螺钉治疗股骨远端骨折的临床疗效。方法:回顾性分析自2013年5月至2016年8月诊治的52例股骨远端骨折患者,采用对侧皮质锁定螺钉+NCB接骨板内固定治疗26例(A组:对侧皮质锁定组),采用锁定螺钉+NCB接骨板内固定治疗26例(B组:锁定螺钉组)。记录两组手术出血量和手术时间、切口长度、内固定治疗后骨折愈合时间、内固定治疗后完全负重时间、内固定治疗后并发症发生率等,在每个随访节点对每位患者进行患肢的正侧位X线平片检查,末次随访时对患肢进行膝关节功能评分,采用美国特种外科医院膝关节评分标准评定患肢功能。骨折愈合的定义为活动时骨折处无痛且在骨折正侧位X线平片上可见到断端骨皮质骨痂连接。术后并发症包括:关节僵硬、内固定断裂、骨不连以及感染等。结果:本研究52例骨折均获得至少12个月的随访。两组在手术相关指标及切口愈合等方面均无明显差异(P均0.05)。在骨折愈合以及完全负重时间方面,A组均显著短于B组(P均0.05)。末次随访时52例患者患肢膝关节功能:A组:优18例,良5例,差4例,优良率88.5%;B组:优15例,良6例,中4例,差1例,优良率80.8%。两组对比A组优良率显著高于B组(P0.05)。两组并发症对比无明显差异:A组发生骨不连2例,骨折内固定断裂2例。B组发生骨不连3例,畸形愈合2例。结论:与传统锁定螺钉相比,对侧皮质锁定螺钉在骨折愈合时间、完全负重时间、术后患肢功能优良率方面具有优势,但在并发症发生率方面没有明显差异。对侧皮质锁定螺钉的治疗指征及自身强度还有待大样本、多中心的临床研究进一步明确。     

Injectable calcium phosphate cement for augmentation around cancellous bone screws. In vivo biomechanical studies

In lower cancellous apparent bone density, it can be difficult to achieve adequate screw fixation and hence stable fracture fixation. Different strategies have been proposed, one of them is through augmentation using calcium phosphate cement in the region at or close to the screw thread itself. To support the hypothesis of an improved screw fixation technique by augmentation of the bone surrounding the implanted screw, in vivo biomechanical and densitometric studies are performed on rabbit specimen where normal and simulated weak bone quality are considered. In particular, the evolution of screw stability till 12 weeks following the implantation is quantified. A statistical significance in the pull out force for augmented versus non-augmented screws was found for the shorter time periods tested of ≤ 5 days whilst the pull out force was found to increase with time for both augmented and non-augmented screws during the 12 week course of the study. The results of the study demonstrate that the use of an injectable calcium phosphate cement which sets in vivo can significantly improve screw pull out strength at and after implantation for normal and simulated weak bone quality.     

Resorbable PLLA-PGA plate and screw fixation in pediatric craniofacial surgery: clinical experience in 1883 patients

The need to provide rigid bony fixation in the surgical treatment of craniofacial deformities has inspired an on-going evolution of surgical innovations and implants. Because of the young age of many treated craniosynostosis patients and the unique pattern of cranial vault growth, the extensive implantation of metal devices is potentially problematic. The use of resorbable plate and screw devices offers all of the benefits of rigid fixation without many of their potential risks. Since the introduction of resorbable plate and screw devices in 1996, tens of thousands of craniofacial patients have received implants, but long-term results from a large series have yet to be reported. A combined prospective and retrospective analysis was done on 1883 craniosynostosis patients under 2 years of age treated by 12 surgeons from seven different geographic locations over a 5-year period who used the same type of resorbable bone fixation devices (poly-L-lacticpolyglycolic copolymer). Specifically, the incidence of postoperative infection, fixation device failure, occurrence of delayed foreign-body reactions, and the need for reoperation resulting from device-related problems were determined. Technical difficulties and trends in device use were also noted. From this series, significant infectious complications occurred in 0.2 percent, device instability primarily resulting from postoperative trauma occurred in 0.3 percent, and self-limiting local foreign-body reactions occurred in 0.7 percent of the treated patients. The overall reoperation rate attributable to identifiable device-related problems was 0.3 percent. Improved bony stability was gained by using the longest plate geometries/configurations possible and bone grafting any significant gaps across plated areas that were structurally important. The specific types of plates and screws used evolved over the study period from simple plates, meshes, and threaded screws to application-specific plates and threadless push screws whose use varied among the involved surgeons. This report documents the safety and long-term value of the use of resorbable (LactoSorb) plate and screw fixation in pediatric craniofacial surgery in the infant and young child. Device-related complications requiring reoperation occurred in less than 0.5 percent of the implanted patients, which is less frequent than is reported for metallic bone fixation. Resorbable bone fixation for the rapidly growing cranial vault has fewer potential complications than the traditional use of metal plates, screws, and wires.     

Effect of pedicle screw diameter on screw fixation efficacy in human osteoporotic thoracic vertebrae

The selection of an ideal screw size plays a crucial role in the success of spinal instrumentation as larger diameter screws are thought to provide better fixation strength but increase the risk of pedicle failure during insertion. On the other hand, smaller diameter screws are with lesser risk of pedicle breakage but are thought to compromise the stability of the instrumentation. By investigating the relationship between screw diameter and the pullout strength of pedicle screws after fatigue loading, this study seeks to find quantitative biomechanical data for surgeons in determining the most ideal diameter size screws when performing surgical implementations on osteoporotic vertebrae.Twenty-seven osteoporotic (BMD ranged: 0.353–0.848 g/cm²) thoracic vertebrae (T3-T8) were harvested from 5 human cadavers. Two sizes of poly-axial screws (5.0 mm × 35 and 4.35 mm × 35) were implanted into each pedicles of the vertebrae by an experienced surgeon. Specimens were randomly distributed into control group, fatigue group of 5000 and 10,000 cycles with peak-to-peak loadings of 10–100 N at 1 Hz. Each specimen was then axial pullout tested at a constant rate of 5 mm/min. The ultimate pullout strength (N) & stiffness (N/mm) were obtained for analysis.The results showed that although the larger diameter screws achieved superior pullout strength immediately after the implantation, both sizes of screws exhibited comparable pullout strengths post fatigue loading. This indicates that the smaller diameter screws may be considered for surgical techniques performed on osteoporotic vertebrae for reduced risk of pedicle breakage without sacrificing fixation strength.     

In Vitro and In Vivo Evaluations of Nano-Hydroxyapatite/Polyamide 66/Glass Fibre (n-HA/PA66/GF) as a Novel Bioactive Bone Screw

In this study, we prepared nano-hydroxyapatite/polyamide 66/glass fibre (n-HA/PA66/GF) bioactive bone screws. The microstructure, morphology and coating of the screws were characterised, and the adhesion, proliferation and viability of MC3T3-E1 cells on n-HA/PA66/GF scaffolds were determined using scanning electron microscope, CCK-8 assays and cellular immunofluorescence analysis. The results confirmed that n-HA/PA66/GF scaffolds were biocompatible and had no negative effect on MC3T3-E1 cells in vitro. To investigate the in vivo biocompatibility, internal fixation properties and osteogenesis of the bioactive screws, both n-HA/PA66/GF screws and metallic screws were used to repair intercondylar femur fractures in dogs. General photography, CT examination, micro-CT examination, histological staining and biomechanical assays were performed at 4, 8, 12 and 24 weeks after operation. The n-HA/PA66/GF screws exhibited good biocompatibility, high mechanical strength and extensive osteogenesis in the host bone. Moreover, 24 weeks after implantation, the maximum push-out load of the bioactive screws was greater than that of the metallic screws. As shown by their good cytocompatibility, excellent biomechanical strength and fast formation and ingrowth of new bone, n-HA/PA66/GF screws are thus suitable for orthopaedic clinical applications.     

Biomechanical measurements on scaphoid bone screws in an experimental model

A number of screws commonly used for internal fixation in scaphoid bone fractures and nonunions are compared regarding biomechanical properties and clinical applicability. The experiments were carried out on models made of ash-wood, representing a reconstruction and fixation as is performed in a cortico-cancellous inlay bone graft for scaphoid non-union. For fixation use was made of 2.7 and 3.5 AO/ASIF cortical screws respectively, 4.0 AO/ASIF cancellous screws, Herbert screws, and a newly designed screw called the three components screw (D.K.S.). The models with implanted screws were tested for bending strength, tensile strength and torsion stability. No large differences between the various screws were found regarding the measured parameters, so that a small intra-osteal implant such as the Herbert screw and the D.K.S., which can be inserted easily and which gives a certain amount of interfragmentary compression, will be sufficient for osteosynthesis of the scaphoid bone. In case an intra-osteal implant is not available a single 3.5 AO/ASIF cortical screw, inserted following lag-screw principles, is recommended.     

Pedicle Screw Fixation Study in Immature Porcine Spines to Improve Pullout Resistance during Animal Testing

The porcine model is frequently used during development and validation of new spinal devices, because of its likeness to the human spine. These spinal devices are frequently composed of pedicle screws with a reputation for stable fixation but which can suffer pullouts during preclinical implantation on young animals, leading to high morbidity. With a view to identifying the best choices to optimize pedicle screw fixation in the porcine model, this study evaluates ex vivo the impact of weight (age) of the animal, the level of the vertebrae (lumbar or thoracic) and the type of screw anchorage (mono- or bi-cortical) on pedicle screw pullouts. Among the 80 pig vertebrae (90- and 140-day-old) tested in this study, the average screw pullout forces ranged between 419.9N and 1341.2N. In addition, statistical differences were found between test groups, pointing out the influence of the three parameters stated above. We found that the the more caudally the screws are positioned (lumbar level), the greater their pullout resistance is, moreover, screw stability increases with the age, and finally, the screws implanted with a mono-cortical anchorage sustained lower pullout forces than those implanted with a bi-cortical anchorage. We conclude that the best anchorage can be obtained with older animals, using a lumbar fixation and long screws traversing the vertebra and inducing bi-cortical anchorage. In very young animals, pedicle screw fixations need to be bi-cortical and more numerous to prevent pullout.     

Anterior vertebral body screw pullout testing with the hollow modular anchorage system--a comparative in vitro study.

Pullout of implants at the proximal and distal ends of multilevel constructs represents a common spinal surgery problem. One goal concerning the development of new spinal implants is to achieve stable fixation together with the least invasive approach to the spinal column. This biomechanical study measures the influence of different modes of implantation and different screw designs, including a new monocortical system, on the maximum pullout strength of screws inserted ventrolaterally into calf vertebrae. The force pullout of eight different groups were tested and compared. Included were three bicortical used single screws (USS, Zielke-VDS, single KASS). To further increase pullout strength either a second screw (KASS) or a pullout-resistant nut can be added (USS with pullout nut). A completely new concept of anchorage represents the Hollow Modular Anchorage System (MACS-HMA). This hollow titanium implant has an increased outside diameter and is designed for monocortical use. Additionally two screw systems suitable for bicortical use were tested in monocortical mode of anchorage (USS, single KASS). We selected seven vertebrae equal in mean size and bone mineral density for each of the eight groups. The vertebral body and implant were connected to both ends of a servohydraulic testing machine. Displacement controlled distraction was applied until failure at the metal-bone-interface occurred. The maximum axial pullout force was recorded. Mean BMD was 312 +/- 55 mg CaHA/ml in cancellous bone and 498 +/- 98 mg CaHA/ml in cortical bone. The highest resistance to pullout found, measured 4.2 kN (KASS) and 4.0 kN (USS with pullout nut). The mean pullout strength of Zielke-VDS was 2.1 kN, of single KASS 2.5 kN, of MACS-HMA 2.6 kN and of USS 3.2 kN. There was no statistically significant difference (t-test, p > 0.05) between bicortical screws and the new monocortical implant. For the strongest fixation at the proximal or distal end of long spinal constructs the addition of a second screw or a pullout-resistant nut behind the opposite cortex offers even stronger fixation.     

Design and testing of external fixator bone screws

In external fixation, bone screw loosening still presents a major clinical problem. For this study, the design factors influencing the mechanics of the bone-screw interface were analysed and various experimental screws designed with the intention of maximizing the strength and stiffness of the inserted screw. Push-in, pull-out and bending tests were then carried out on the three experimental screws, and on two commercially available screws in both a synthetic material and in cadaveric bone; photoelastic tests on different screw threadforms were also performed. The results of the push-in and pull-out tests indicate that both the screw threadform and cutting head have a significant effect on the holding strength of the screw. The photoelastic tests show that most of the applied load is distributed over the first few threads closest to the load, and that the area between the thread crests is subjected to high shear stresses.     

Endoscopic foreheadplasty: a histologic comparison of periosteal refixation after endoscopic versus bicoronal lift

Endoscopic brow lift techniques using temporary fixation rely on rapid readherence of the periosteum to calvarial bone. Little is known about the histologic events that occur during the early postoperative period after these procedures. An animal study was designed to compare and contrast periosteal fixation to bone and unelevated periosteum, with endoscopic and bicoronal brow lift techniques. One method of temporary fixation is the use of absorbable (polylactic/polyglycolic acid copolymer) LactoSorb screws; a histologic analysis of implanted LactoSorb screws was also performed. Sixteen rabbits underwent brow lifts; eight underwent endoscopic brow lift and fixation with LactoSorb screws without skin excision, and another eight underwent traditional bicoronal brow lift with skin excision and closure under tension. Animals were killed 1, 2, 6, and 12 weeks after the procedures were performed to evaluate the interaction of periosteum and bone and the normal, unelevated periosteum/calvarium interface at a site distant from the operative area. Histologic specimens were examined for the degree of apposition of periosteum to bone and for any fibrous or bony reaction at this interface. Histologic analysis showed various degrees of periosteal fibrosis and fixation to calvarial bone. After an initial phase of minimal periosteal adherence and moderate inflammation, the periosteum became progressively more adherent to bone in both groups, with no significant differences between treatment groups in rates of fixation. Fixation required at least 6 weeks. LactoSorb screws were surrounded by an area of mild inflammation and were progressively hydrolyzed and digested. Periosteal fixation increases over time for bicoronal and endoscopic brow lifts with minimal differences between the two techniques. With this animal model, periosteal adherence to calvarium requires at least 6 weeks with complete adherence by 12 weeks. In addition, the use of absorbable fixation screws seems to be both effective and well tolerated. The histologic changes associated with periosteal healing observed in this study suggest that permanent or semipermanent fixation may improve the accuracy and early postoperative maintenance of forehead advancement.     

空心钉配合缝线张力带技术治疗移位的肱骨大结节骨折

目的:探讨使用空心钉配合缝线张力带技术治疗移位的肱骨大结节骨折的效果。方法:2008年3月-2010年3月,收治12例肱骨大结节骨折病人,男10例,女2例,年龄21-71岁,平均年龄46.3岁。其中8例摔伤,2例车祸外伤,2例运动中损伤并伴有盂肱关节脱位。受伤至手术时间5小时-1周。X线显示大结节骨折移位大于5mm。大结节骨折块采用空心钉配合5-Ethibond缝线构成的张力带技术进行固定。结果:患者伤口均一期愈合无感染等并发症发生,所有患者均获随访,随访时间9-33个月,平均14个月。X线显示术后2-4个月骨折愈合,平均2.5个月。美国加州大学洛杉矶分校评分标准评分为(33.65±3.83)分;优9例,良2例,可1例,优良率91.7%。结论:采用切开复位空心钉配合缝线张力带技术治疗肱骨大结节骨折疗效满意,功能恢复良好,疼痛缓解明显。     

Finite Element Analysis of Minimal Invasive Transforaminal Lumbar Interbody Fusion

The purpose of our study is to develop and validate three-dimensional finite element models of transforaminal lumbar interbody fusion, and explore the most appropriate method of fixation and fusion by comparing biomechanical characteristics of different fixation method. We developed four fusion models: bilateral pedicle screws fixation with a single cage insertion model (A), bilateral pedicle screws fixation with two cages insertion model (B), unilateral pedicle screws fixation with a single cage insertion model (C), and unilateral pedicle screws fixation with two cages insertion model (D); the models were subjected to different forces including anterior bending, posterior extension, left bending, right bending, rotation, and axial compressive. The von Mises stress of the fusion segments on the pedicle screw and cages was recorded. Angular variation and stress of pedicle screw and cage were compared. There were differences of Von Mises peak stress among four models, but were within the range of maximum force. The angular variation in A, B, C, and D decreased significantly compared with normal. There was no significant difference of angular variation between A and B, and C and D. Bilateral pedicle screws fixation had more superior biomechanics than unilateral pedicle screws fixation. In conclusion, the lumbar interbody fusion models were established using varying fixation methods, and the results verified that unilateral pedicle screws fixation with a single cage could meet the stability demand in minimal invasive transforaminal interbody fusion.     

Spinal pedicle finder for transpedicular screw fixation--design and early clinical result

Spinal transpedicular fixation has gained widespread popularity in the past 5 years. In biomechanical studies, the deeply-inserted transpedicular screws withstood the largest number of cycles in the cephalad-caudad and medial-lateral direction before failure. However, in clinical practice, the risk of screw placement which is too far medially or too far laterally do exist. The optimization of increasing screw depth to avoid complication is of significant clinical importance. A Spinal Pedicle Finder (S.P.F) has been designed for transpedicular screws and a prototype has been completed. It is composed of an I-shaped body with a pair of front rails and a pair of rear rails. The front rail comprises two positioning arms that fit against the laminal bony crest, and the rear rail comprises two guiding bases that provide the transpedicular pin inserted with a specific angle. Both positioning arms and both guiding bases can be adjusted synchronously, and the specific angle over the guiding bases can be pre-set preoperatively according to the angle of pedicle axis. To date, in 7 cases (5 fracture and 2 spondylolisthesis) transpedicular screw fixation has been applied by aid of the S.P.F. Two-level fixation was applied in a fracture group and three-level fixation was applied in a spondylolisthesis group. The position of the transpedicular screw has been checked by CT scan postoperatively. A total of 32 transpedicular screws were inserted and all were in the pedicle and vertebral body except in one instances. One transpedicular screw was malpositioned on one side, partially lateral to the pedicle. However, this malposition did not cause any neurologic problem, such as dural tear, nerve root injury or other. Clinical experience has demonstrated its efficacy and safety.     

微创经皮钢板联合锁定加压钢板固定术治疗胫骨干骺端骨折的临床疗效

目的:探讨微创经皮钢板固定技术(MIPPO)与锁定加压钢板(LCP)治疗胫骨干骺端骨折的临床疗效。方法:选择2013年6月-2015年6月在我院接受手术治疗的胫骨干骺端骨折患者103例作为研究对象,根据手术方法不同将所选患者分为三组。其中,联合手术组(35例)患者采用MIPPO联合LCP内固定术治疗,外固定组(33例)患者采用超关节外固定支架术治疗,内固定术组(35例)患者采用切开复位钢板内固定术治疗。观察并比较三种手术方法的临床效果及对患者骨关节功能的影响。结果:与外固定术组及内固定术组比较,联合手术组患者的手术时间短,术中出血量少,骨折愈合时间早,差异具有统计学意义(P0.05);联合手术组患者的手术优良率高于外固定组和内固定组,差异有统计学意义(P0.05);内固定组手术优良率高于外固定组,差异具有统计学意义(P0.05);联合手术组患者术后并发症的发生率低于外固定组及内固定组,差异具有统计学意义(P0.05);外固定组与内固定组术后并发症的发生率比较,差异无统计学意义(P0.05)。结论:MIPPO联合LCP内固定治疗胫骨干骺端骨折具有手术切口小、术中出血量少、术后并发症发生率低、骨折愈合快、关节功能恢复较好等优点,是治疗胫骨干骺端骨折的理想方法,值得临床推广应用。     

Enhanced bone screw fixation with biodegradable bone cement in osteoporotic bone model

Purpose: The purpose of this study was to study the potential of novel biodegradable PCL bone cement to improve bone screw fixation strength in osteoporotic bone. Methods: The biomechanical properties of bone cement (ε-polycaprolactone, PCL) and fixation strength were studied using biomechanical tests and bone screws fixed in an osteoporotic bone model. Removal torques and pullout strengths were assessed for cortical, self-tapping, and cancellous screws inserted in the osteoporotic bone model (polyurethane foam blocks with polycarbonate plate) with and without PCL bone cement. Open cell and cellular rigid foam blocks with a density of 0.12 g/cm3 were used in this model. Results: Removal torques were significantly (more than six-fold) improved with bone cement for cancellous screws. Furthermore, the bone cement improved pullout strengths three to 12 times over depending on the screw and model material.?Conclusions: Biodegradable bone cement turned out to be a very potential material to stabilize screw fixation in osteoporotic bone. The results warrant further research before safe clinical use, especially to clarify clinically relevant factors using real osteoporotic bone under human body conditions and dynamic fatigue testing for long-term performance.     

椎弓根螺钉用于植骨融合术治疗胸腰椎结核的临床研究

目的:探讨椎弓根内固定联合植骨融合术治疗胸腰椎结核的临床效果。方法:回顾性分析2013年5月至2014年5月在我院接受治疗的50例胸腰椎结核患者的临床资料,结合影像资料评价患者手术前后的红细胞沉降率、后凸畸形矫正情况、Frankel分级及术后并发症的发生情况等。结果:所有患者术后病理均证实为脊柱结核,术中27例植入大块自体髂骨,23例植入自体肋骨捆绑植骨。24例采用椎体侧前方钉棒内固定,26例采用后路椎弓根螺钉系统内固定。术中未出现脊髓、神经、血管损伤及血气胸等并发症。患者术后红细胞沉降率获得改善,差异具有统计学意义(P0.05)。术后Cobb角明显获得矫正,差异具有统计学意义(P0.05)。患者术后脊柱损伤程度明显改善,差异具有统计学意义(P0.05)。结论:椎弓根内固定联合椎体间植骨融合术治疗胸腰椎结核具有良好的临床效果,不仅可以改善红细胞沉降率,而且可以矫正患者脊柱后凸畸形,值得临床推广应用。     

一期外固定联合锁定钢板内固定术治疗C型pilon骨折的临床疗效

目的：探讨外固定架联合锁定钢板分期治疗C 型pilon 骨折的临床疗效。方法：选取2010 年3 月至2011 年4 月在我院接受治疗的C型pilon 骨折患者17 例。按照分期治疗的原则,先行一期外固定架固定术,待局部软组织恢复后切开复位,再行锁定钢板内固定术进行治疗,术后对患者进行一年的随访,定期检查患者的踝关节功能,并借助影像学资料对临床疗效进行评价。结果：全部患者获得随访,平均愈合时间为（4.1± 1.6）月;平均AOFAS 评分为（83.1± 12.4）分,其中优6 例（35.2 %）,良8 例（47.1 %）,一般2 例（11.8 %）,差1 例（5.9 % ）,优良率为82.4 %;术后4 例患者出现出现轻度感染,通过局部换药、抗生素和钉道护理得到控制。结论：采用一期外固定联合锁定钢板内固定术分期治疗C 型pilon 骨折,可以有效地提高治疗效果,值得临床推广。     

A new adhesive technique for internal fixation in midfacial surgery

Background  

The current surgical therapy of midfacial fractures involves internal fixation in which bone fragments are fixed in their anatomical positions with osteosynthesis plates and corresponding screws until bone healing is complete. This often causes new fractures to fragile bones while drilling pilot holes or trying to insert screws. The adhesive fixation of osteosynthesis plates using PMMA bone cement could offer a viable alternative for fixing the plates without screws. In order to achieve the adhesive bonding of bone cement to cortical bone in the viscerocranium, an amphiphilic bone bonding agent was created, analogous to the dentin bonding agents currently on the market.     

俯卧位后外侧入路联合内侧切口治疗三踝骨折35 例的临床疗效评价

目的:探讨在俯卧体位下采用后外侧入路联合内侧切口治疗三踝骨折方法的临床疗效及安全性。方法:选择2014年1月~2015年1月在我院治疗并由同一治疗组医生采用俯卧体位下治疗的三踝骨折患者35例,治疗外踝骨折时将钢板置于腓骨后侧或外侧,使用钢板或螺钉对后踝骨折进行固定,2枚拉力螺钉固定内踝。观察术后切口及骨折愈合、踝关节功能恢复情况。术后定期随访,采用AOFAS踝-后足评分标准对踝关节功能进行评价。结果:手术时长50~142 min,平均90 min,1例患者内侧切口出现局部红肿,抬高患肢及定期换药后局部红肿好转,未出现明显切口感染征象。2例病人术后出现足背部麻木,分别在术后6周、9周时消失。随访时间6~18月,平均随访15个月。术后3月X线显示所有病人骨折线模糊,骨痂生长良好,按美国足踝外科协会踝-后足评分系统评分:优28例,良5例,可2例,优良率94.29%。结论:在俯卧体位下采用后外侧切口治疗三踝骨折可一次性复位、固定后踝和外踝骨折,联合内侧切口可在一个体位下完成三踝骨折的手术,缩短手术时间,对软组织破坏少,骨折可获得解剖复位,术后踝关节功能恢复佳,可降低因反复翻身而污染术野的概率。