可吸收螺钉在颈椎前路固定术中的应用

１９９５年１０月至１９９６年１０月，作者采用可吸收螺钉对１４例颈椎前路手术行植骨块内固定术。术后随访平均８．３个。患者脊髓压迫症状缓解，植骨块稳定，植骨全部愈合，疗效优良。作者认为：可吸收螺钉内固定可靠，不需二次手术取出，不干扰磁影像，无毒性，无副作用，是颈前路内固定的理想材料。     

前路减压植骨可吸收螺钉内固定治疗颈椎病

目的:观察颈椎前路减压植骨可吸收螺钉内同定治疗颈椎病的初步临床疗效.方法:2007年3月～2008年9月我院应用颈椎前路减压植骨可吸收螺钉内固定治疗颈椎病患者26例,男16例,女10例,年龄38～70岁,平均49.4岁.脊髓型颈椎病11例,神经根型颈椎病5例,混合型颈椎病10例.1个椎间隙受压8例,2个椎间隙受压18例.所有患者采用标准颈椎前路减压、自体髂骨块植骨,应用可吸收全螺纹螺钉自植骨块纵轴中线与冠状面呈45°角方向将植骨块固定于上、下椎体.术后常规颈托同定4～6周.每月门诊随访拍片,观察植骨块位置及植骨愈合情况.了解植骨块融合时间;应用JOA评分评估神经恢复情况.结果:手术均顺利完成,可吸收螺钉固定顺利.术后1周,患者手术切口均I/甲愈合.全部病例获4～18个月平均12.6个月随访,植骨块与周围融合时间3.2～4.6个月,平均3.3±0.6个月,症状改善总体优良率84.2%,未观察到明显全身不良反应及局部并发症.结论:颈椎前路减压植骨可吸收螺钉内固定术可有效治疗单或双节段颈椎病,避免金属内同定物产生的相关并发症.     

颈前路钢板内固定治疗脊髓型颈椎病39例体会

目的观察颈前路钢板在脊髓型颈椎病手术中的作用和疗效。方法对39例脊髓型颈椎病患者行颈前路减压植骨、颈前路钢板内固定术,术后随访观察神经功能恢复情况、植骨融合率及有无植骨并发症。结果术后进行6—18个月（平均10个月）随访。症状明显缓解、脊髓功能明显改善者36例,占90％。术后8个月植骨融合率达到100％。无钢板断裂、螺钉松动、植骨不愈合、椎体高度丢失现象存在。结论应用颈前路减压植骨、颈前路钢板系统内固定术治疗脊髓型颈椎病具有以下优点：可获得术后颈椎即刻稳定,防止植骨块移位,手术时间短,术后无需行石膏固定,能显著提高植骨融合率。     

腰椎滑脱症翻修手术(附21例报告)

目的探讨腰椎滑脱症初次手术失败原因、翻修手术方式及疗效。方法回顾分析2003年4月～2006年10月21例腰椎滑脱症翻修手术病例,针对初次手术失败的原因,分别应用后路椎弓根螺钉复位内固定加椎体间植骨融合术、后路椎弓根螺钉复位内固定加前路椎体间植骨融合术以及后路椎弓根螺钉复位内固定加前路游离腓骨移植椎体间植骨融合术进行再次手术,比较术后疗效、滑脱椎体复位率以及植骨融合率。结果本组全部患者翻修手术后均获随访,时间为4～48个月,平均32.6个月,总体优良率为90.48%,所有翻修手术病例植骨融合良好,植骨融合最短时间为3.8个月,最长时间为6.4个月,滑脱椎体再次复位后矫正度无丢失,椎弓根螺钉无松动及断裂。结论腰椎滑脱症初次手术失败原因主要与手术方式选择不当、忽视植骨融合的质与量以及手术操作不当有关,只要翻修手术方式得当、术中仔细操作、合理应用内固定及植骨融合材料,仍能取得满意疗效。     

Secuplate颈前路钢板系统在脊髓型颈椎病手术中的应用

目的观察Secuplate颈前路钢板在脊髓型颈椎病手术中的作用和疗效。方法对26例脊髓型颈椎病患者行颈前路减压植骨、Secuplate颈前路钢板内固定术。术后随访观察神经功能恢复情况、植骨融合率及有无植入物并发症。结果术后进行6～12个月(平均8个月)随访。术后症状明显缓解、脊髓功能明显改善者23例,占88%。术后6个月植骨融合率达到100%。无钢板和螺钉松动或断裂现象存在。结论应用颈前路减压植骨、Secuplate颈前路钢板系统内固定术治疗脊髓型颈椎病具有以下优点:可获得术后颈椎即刻稳定,防止植骨块移位,术后无需行石膏固定,能显著提高植骨融合率。     

颈椎前路手术ZEPHIR钢板内固定临床应用

目的探讨ZEPHIR钢板在前路手术中应用的价值。方法28例颈椎疾病患者行颈椎前路手术及ZEPHIR钢板内固定，其中颈椎骨折脱位16例，颈椎间盘突出12例。结果28例中26例随访4～15个月，1例14个月后钢板下极螺钉松动，余25例钢板螺钉固定位置良好，植骨块无移位，26例均已达骨性融合。结论ZEPHIR钢板有优良植入物设计和力学性能，可获得术后颈椎即刻稳定，防止植骨块移位，无需外固定，能显著提高植骨融合率。     

颈前路带锁钢板治疗下颈椎损伤(附38例报告)

目的：研究颈前路带锁钢板在下颈椎损伤手术中的应用。方法：2000年4月-2002年4月止采用颈椎前路减压、植骨融合、带锁钢板内固定治疗下颈椎骨折脱位并颈髓损伤38例，其中单节段22例，双节段12例，三节段4例；Frankel分级：A级4例，B级12例，C级16例，D级6例。结果：术后随访6-12月，平均10.5月，38例植骨块于3月内骨性愈合，平均愈合时间为2.6月，脊髓功能均有不同程度恢复，Frankel分级平均提高1.4级，无1例有骨不连、植骨块脱出、钢板螺钉松动脱出等并发症。结论：颈前路带锁钢板是颈椎前路减压、植骨融合手术中较为安全、有效的内固定系统。     

颈前路钢板置入定位技巧探讨

颈前路钢板内固定术是颈椎常规手术之一。手术时，如将螺钉拧入植骨块——椎体界面上或椎间隙内是术后假关节形成的原因之一。为了减少螺钉置入的盲目性，提高钢板定位的准确性，避免内固定不牢、内固定物过早松动而出现的严重并发症．我们通过临床实践应用注射针头插入作为定位标记的方法，简单可靠，现报道如下。     

一期后路经关节螺钉联合前路钢板固定治疗下颈椎骨折脱位

目的 探讨一期后路经关节螺钉联合前路钢板固定技术治疗下颈椎骨折脱位的效果. 方法 自2005年10月至2007年5月对12例下颈椎骨折脱位患者采用一期前后路联合手术.单纯脱位者,先行后路复位经关节突螺钉固定,再改行前路椎间隙减压,植骨融合,钢板内固定;椎体骨折伴脱位者,前路先行椎体次全切除,植骨融合,钢板内固定,然后行后路经关节螺钉固定脱位节段,小关节间行植骨融合.术前ASIA分级:A级21例,B级6例,C级3例,D级1例. 结果 12例患者获6～21个月(平均14.8个月)随访,椎间及小关节间植骨全部愈合.无螺钉松动及神经、血管并发症.术后除1例完全性瘫痪患者神经功能无恢复外,其余11例均有一级以上恢复.术后ASIA分级:A级1例,B级1例,C级4例,D级4例,E级2例. 结论 下颈椎经关节螺钉联合前路钢板固定融合术,具有操作简单安全、固定可靠、植骨融合率高等优点,是治疗下颈椎骨折脱位较为理想的术式.     

高原颈椎前路椎间融合后不同固定方式的生物力学特性的研究

[目的]分析比较颈椎前路椎间融合后不同固定方式的生物力学特性.[方法]建立正常高原人C5/6的三维有限元模型.利用有限元软件ANSA13.0.2对模型进行有限元网格划分,最后加入韧带和关节囊,通过模拟前路手术摘除椎间盘建立椎间植骨融合的有限元模型,加入前路内固定器及后路椎弓根系统三种三维有限元模型.各模型施加前屈/后伸,左/右侧弯,左/右旋转6种生理载荷,模拟颈椎6个方向的生理活动.[结果]前路和后路2种固定方式均明显减少了前路椎体融合植骨块的应力,后路固定较前路固定更减少了植骨块的应力.主要的应力集中在椎体和螺钉交界处,不同方向运动上下螺钉承受的应力没明显差异.[结论]前路椎体间融合后通过前路和后路固定均可以降低植骨块的应力,达到手术后的初始稳定性,后路椎弓根固定在前路融合后其生物力学的稳定性强于前路钢板固定.     

金属松质骨螺钉拔出力的研究

金属松质骨螺钉是应用于骨折内固定最广泛的材料之一，临床上有许多螺钉的松动、脱出导致内固定的失败的病例报道。螺钉的松动、脱出与螺钉的拔出力有关。螺钉拔出力与螺钉的材料、螺纹的几何形态、骨质量、螺钉操作技术等密切相关。     

Atlantoaxial transarticular screw fixation and posterior fusion using ultra-high-molecular-weight polyethylene cable

This article attempts to evaluate the effectiveness of the ultra-high-molecular-weight polyethylene (UHMW-PE) cable system in atlantoaxial transarticular screw fixation and posterior fusion through the clinical results of 10 postoperative patients with atlantoaxial subluxation secondary to rheumatoid arthritis. Among them, one patient with only one screw placed owing to an anomalous vertebral artery had the correction loss of the 3-mm atlas-dens interval after surgery. Another patient had a second operation to remove the screw and cable after 2 years 11 months because a unilateral transarticular screw had come to protrude through the lateral mass of the atlas ventrally. All patients had achieved C1-C2 osseous fusion without any complications associated with this cable system. The UHMW-PE cable is a very useful material as sublaminar wiring in atlantoaxial transarticular screw fixation and posterior fusion.     

Factors affecting fixation of the glenoid component of a reverse total shoulder prothesis

The semiconstrained design of the reverse arthroplasty allows loads from the humerus to challenge the fixation of the glenoid component to the scapula. We examined some of the factors affecting the quality of glenoid screw fixation, including the density of the material into which the screws are placed, the purchase of individual screws, and the direction of loading in relation to screw placement. Loads were applied by the humeral component to glenoid components with different conditions of fixation. The load to failure for each set of conditions was measured and compared statistically. Load to failure was less when the glenoid component was fixed to material of lesser density. Each screw contributed to the quality of fixation; the screw nearest the point of load application made the largest contribution. Load to failure was less when the load was colinear with a line through the nonlocking holes in the base plate compared to colinear with a line through the locking holes. In performing a reverse total shoulder, surgeons should emphasize secure intraosseous placement of the fixation screws in the best quality bone available. The placement of the inferior screw appears to be the most critical.     

Biomechanical evaluation of osteoporotic fracture: Metal fixation versus absorbable fixation in Sawbones models

ObjectiveThe failure of osteoporotic fracture after internal fixation is mainly caused by the underlying bone loss and strength compromise. The aim of this study is to investigate whether absorbable internal fixation can provide adequate mechanical stability and a reduction in the incidence of failure of fixation caused by bone loss and stress shielding.MethodsA low density cancellous bone model was selected to compare the insertion of screw (screw-in), removal of screw (screw -out) and pull - out strength of absorbable screw and metal screw. The long bone model of thin cortical bone was used to create the transverse fracture model. The model was fixed with absorbable plate-screw system and metal plate-screw system respectively. The fatigue test and static bending test were compared. Moreover, the size of screw hole area was assessed.ResultsThe maximal screw - in and screw - out torque of the absorbable screw was significantly greater than that of the metal screw (P < 0.05), but there was no significant difference in pull-out test (P > 0.05). No visible failure occurred in fatigue test. There was no significant difference between the maximum load of static bending test (P > 0.05). The screw hole area of absorbable samples was significantly smaller than that of metal samples (P < 0.05).ConclusionsIn this experimental set-up it was found that the stability of absorbable screws in osteoporotic bone was better than metal screws. The absorbable system tested can achieve good stability, and the destruction of osteoporotic bone is small, which can reduce the occurrence of bone failure. Considering that absorbable material avoids the need of second surgery (implant removal) and reduces the stress shielding effect, we believe that absorbable internal fixation can be considered for fixation treatment of osteoporotic fractures.     

Biodegradable screw fixation of the syndesmosis together with metallic osteosynthesis. Preliminary experience of 7 ankles

BACKGROUND AND AIMS: In ankle fractures with separation of the tibiofibular mortise a metallic syndesmosis screw is generally used. As a rule, this transfixing screw is removed by a separate operation 6 to 8 weeks later. Usually the fracture fixation implants are removed by a second operation later on. In order to eliminate separate removal of the transfixing screw, we used a biodegradable syndesmosis screw in a pilot clinical study. PATIENTS AND METHODS: We treated seven consecutive patients with malleolar fractures and separation of the syndesmosis by an ordinary metallic plating and screw fixation of the fractures and biodegradable polyglycolic acid (PGA) screw transfixation of the syndesmosis. RESULTS AND CONCLUSIONS: All the patients ended up with an acceptable result and stable ankle mortise. One of the ankles, which was the only one fixed by two transfixing PGA screws instead of one screw, had transient sinus formation and intraosseal osteolysis. The final result was good also in this case. The ankle mortise can be fixed safely by biodegradable screws in connection with metallic osteosynthesis of malleolar fractures. Thus a separate removal of the transfixing material is possible to eliminate.     

枢椎骨折合并相邻节段不稳手术方法的选择

目的通过医学影像学资料回顾性研究,为治疗枢椎骨折合并相邻节段不稳选择合理的手术方法。方法回顾性分析13例枢椎骨折的相关资料,依据枢椎骨折的类型及相邻节段稳定情况,采用颈前路钢板植骨内固定术2例,后路C1、2椎弓根钉固定术3例,后路C2、3椎弓根钉固定术3例,后路寰枢椎椎弓根钉加C3侧块螺钉固定术2例,齿状突螺钉内固定术3例。结果本组获随防6~24个月(平均12个月),术后3个月均获得骨性融合,无内固定系统松动、断钉,无脊髓神经、椎动脉损伤等手术并发症。临床症状明显改善,颈椎生理曲度保持良好,合并脊髓损伤的3例,按ASIA分级均有不同程度恢复。结论针对枢椎骨折的类型及相邻节段不稳的情况,合理选择个性化手术方案,可以获得良好的疗效。     

下颈椎后路螺钉固定的生物力学研究进展

目前,下颈椎后路螺钉固定除侧块螺钉和椎弓根螺钉技术已普遍应用外,经关节螺钉和经椎板螺钉固定技术也逐渐被重视。本文就此介绍下颈椎后路4种螺钉固定方式,并对各自固定技术的生物力学研究现状进行综述。生物力学研究内容包括三维稳定性、抗拔出力、置钉技术和螺钉特点等。侧块螺钉和椎弓根螺钉技术,因其优越的三维稳定性和较强的抗拔出力,已经作为下颈椎不稳的一种有效固定方法。经关节螺钉固定作为一种新的下颈椎后路固定方法,具有广范的手术适应证,并且该技术相对安全、简易,临床上也取得了良好的疗效。经椎板螺钉固定技术临床应用不多,但通过解剖学和生物力学研究证实,该技术可成为临床上可行的补救技术。上述4种下颈椎后路螺钉固定技术,各有其优劣,临床应用也各不相同,通过对这些技术的生物力学研究,将有助于下颈椎后路螺钉内固定技术的发展,更有效的指导临床工作。     

Axial Loading Screw Fixation for Chevron Type Osteotomies of the Distal First Metatarsal: A Retrospective Outcomes Analysis

The distal chevron osteotomy is a widely accepted technique for the treatment of hallux abductovalgus deformity. Although the osteotomy is considered to be stable, displacements of the capital fragment has been described. We propose a new method for fixation of the osteotomy involving the axial loading screw (ALS) used in addition to single screw fixation. We believe this method will provide a more mechanically stable construct. We reviewed the charts of 46 patients in whom 52 feet underwent a distal chevron osteotomy that was fixated with either 1 screw or 2 screws that included the ALS. We hypothesized that the ALS group would have fewer displacements and would heal more quickly than the single screw fixation group. We found that the group with ALS fixation had healed at a mean of 6.5 weeks and that the group with single screw fixation had healed at 9.53 weeks (p = .001). Also, 8 cases occurred of displacement of the capital fragment in the single screw, control group compared with 2 cases of displacement in the ALS group. However, this finding was not statistically significant. The addition of the ALS to single screw fixation allowed the patients to heal approximately 3 weeks earlier than single screw fixation alone. The ALS is a fixation option for the surgeon to consider when osseous correction of hallux abducto valgus is performed.     

Biomechanical evaluation of patellar- and hamstring tendon graft fixation for anterior cruciat ligament reconstruction using a poly-(D, L-lactide) interference screw

Anterior cruciate ligament (ACL) reconstruction using autologous hamstring tendons are being performed more frequently and satisfactory results have been reported. Advantages such as low donor site morbidity and ease of harvest as well as disadvantages like low initial construct stiffness have been described. Recently, it has been demonstrated that graft fixation close to the original ACL insertion sites increases anterior knee stability and graft isometry. Hamstring tendon fixation techniques using interference screws offer this possibility. To reduce the risk of graft laceration, a round threaded titanium interference screw (RCI) was developed. To improve initial fixation strength, fixation techniques for hamstring tendons with separate or attached tibial bone plugs were introduced. However, data on fixation strength do not yet exist. With respect to the proposed advantages of biodegradable implants, like undistorted magnetic resonance imaging, uncompromised revision surgery and a decreased potential of graft laceration during screw insertion, we performed pullout tests of round threaded biodegradable and round threaded titanium interference screw fixation of semitendinosus (ST) grafts with and without distally attached tibial bone plugs. Data were compared with bone-tendon-bone (BTB) graft fixation using biodegradable and conventional titanium interference screws. We used 56 proximal calf tibiae to compare maximum pullout force, screw insertion torque, and stiffness of fixation for biodegradable direct ST tendon and bone plug fixation (group I: without bone plug, group II: with bone plug) versus titanium interference screw fixation (group III: without bone plug, group IV: with bone plug). A round threaded biodegradable poly-(D, L-lactide) (Sysorb) and a round threaded titanium interference screw (RCI) were used. As a control calf bone-tendon-bone (BTB) grafts fixed with either poly-(D, L-lactide) (group V) or conventional titanium (group VI) interference screws were used. ST tendons were harvested either with or without their distally attached tibial bone plugs from human cadavers and were folded to a three-stranded graft. Specimen were loaded in a material testing machine with the applied load parallel to the long axis of the bone tunnel. Maximum pullout force of ST bone plug (group III: 717 N +/- 90, group IV: 602 N +/- 117) fixation was significantly higher than that of direct tendon (group I: 507 N +/- 93, group III: 419 N +/- 77) fixation. Maximum pullout force of biodegradable screw ST fixation was higher than that of titanium screw fixation in both settings. There was no significant difference in pullout force between biodegradable (713 N +/- 210) and titanium (822 N +/- 130) BTB graft fixation or between ST fixation with bone plug and biodegradable screw with BTB fixation. Pullout force of hamstring tendon interference screw fixation can be improved by using a biodegradable implant. In addition, initial pullout force can be greatly improved by harvesting the hamstring tendon graft with its distally attached tibial bone plug. This may be important, especially in improving tibial graft fixation. This study encourages further research in tendon-bone healing with direct interference screw fixation to confirm the potential of this advanced method.