前路螺钉内固定治疗成人齿状突骨折

目的　总结前路螺钉内固定治疗齿状突骨折的经验。方法　采用前路螺钉内固定治疗成人齿状突骨折 15例 ,其中男 11例 ,女 4例 ,Anderson -D′AlonzoⅡ型骨折 10例 ,Ⅲ型骨折 5例。结果　随访 1～ 5年 ,骨折均获骨性愈合。临床症状完全消失 12例 ,明显减轻者 3例 ,均无明显颈部活动受限。结论　前路螺钉内固定技术的主要优越性在于保存了寰枢椎的生理活动 ,而术前骨折解剖复位是保证手术成功的关键所在。     

单枚螺钉前路固定AndersonⅡ型齿状突骨折

目的 回顾分析18例齿突骨折前路螺钉固定术，探讨手术的安全性和疗效。方法 1998年12月至2004年2月，前路螺钉固定治疗创伤性AnclersonⅡ型齿突骨折脱位18例，男15例，女3例，平均42．2岁。所有病例术前均行颅骨牵引，受伤后平均5d内行前路齿突螺钉固定手术，术后颈围保护6周。进行了定期的临床和X线检查随访。结果 平均随访15．8个月。得到随访的17例骨折全部骨性愈合，无术中及术后并发症，无内固定螺钉松动，移位或断裂。结论 前路螺钉固定治疗齿突骨折既可提供良好的稳定性又能保留寰枢关节活动性，骨折愈合率较高，并发症低，是治疗AidersonⅡ型齿突骨折较好的方法。     

颈前路加压螺丝内固定治疗齿状突骨折

目的评价颈前路加压螺钉内固定在治疗齿状突骨折中的应用及效果。方法对9例急性齿状突骨折的患者，在透视监视下行颈前路加压螺钉内固定术并分析其结果。结果9例患者中，术后除1例病人出现短暂左上肢无力外，余均获得了满意疗效。随访11～42个月，平均17个月，齿状突骨折愈合良好，无不稳定或假关节形成。结论前路直接加压螺钉内固定是治疗齿状突骨折的一种有效方法，在重建环枢复合体稳定性的同时，完全保留了其间的运动功能。精确的操作技术和恰当的适应证选择是手术成功的关键。     

AOSF技术治疗Ⅱ型和浅Ⅲ型齿状突骨折疗效分析

目的 探讨前路齿状突螺钉内固定技术治疗Ⅱ型和浅Ⅲ型齿状突骨折安全性和临床疗效.方法 应用前路齿状突螺钉内固定技术治疗齿状突骨折32例,男23例,女9例.年龄19～78 岁,平均(52.6±3.2) 岁.按Anderson-D′Alonzo分型,Ⅱ型20例,浅Ⅲ型12例.均采用1枚空心加压螺钉固定.通过上颈椎正侧位及张口位X线片和CT进行评价.结果 32例均获得随访,随访时间6～28月,平均18个月.除2例Ⅱ型骨折未愈合外,其余平均愈合时间6个月.无螺钉断裂、移位及神经损伤等并发症.临床症状完全消失26例,3例遗留颈部僵硬感,但临床检查无活动受限,2例合并颅脑损伤者残留部分头痛、头晕.结论 前路齿状突螺钉内固定技术是治疗Ⅱ型和浅Ⅲ型齿状突骨折有效和安全的方法,能最大限度地保留寰枢椎的生理活动功能.     

齿状突Ⅱ型骨折前路内固定脊状钛螺钉的研制及生物力学研究

目的：研究应用于齿状突Ⅱ型骨折前路内固定的新型抗旋转中空脊状钛螺钉，并进行生物力学研究。方法：将12个头颈椎复合体（C0－C3）随机分为3组：脊状螺钉组，双螺纹螺钉组及双螺钉组，分别测量各组正常时，齿状突Ⅱ型骨折复制后，螺钉内固定后及6000次循环加载疲劳试验后各状态下的C0－C2节段各运动方向的总刚度。结果：齿状突骨折后，C0－C2节段各运动方向的总刚度均显著下降；3种螺钉内固定后提供的各运动方向的瞬时总刚度（除脊状螺钉组前屈运动方向外）均显著小于正常状态下相应运动方向和刚度，各组间瞬时总刚度比较：脊状螺钉组及双螺纹螺钉组旋转刚度显著大于双螺钉固定组，各组间疲劳试验后总刚度比较，脊状螺钉组的屈伸，侧弯运动刚度均大于其他两组；脊状螺钉组的旋转运动刚度显著大于双螺钉组，而双螺纹螺钉组与双螺钉组无显著差别，结论：脊状螺钉优于其他类型的螺钉，尤其表现在抗旋转及抗疲劳能力上。     

Feasibility of Anterior Fixation with Single Screw for Odontoid Fractures in Pediatrics: A Computed Tomographic Study

Objective

Although it is an effective fixation technique for an unstable odontoid, anterior fixation remains challenging in pediatric populations. Our study measures the anatomical parameters of the odontoid to identify the feasibility of anterior fixation with a single screw for children.

Methods

We retrospectively collected data from 112 normal male and female children (aged between 2 and 18) in our institute from January 1, 2022 to December 31, 2022. Subjects were divided into a youth group (2–6 years old), a juvenile group (7–12 years old), and an adolescent group (13–18 years old). Sagittal and coronal computed tomography images of the upper cervical spine were used to measure the screw length, angle, and inner and outer diameters of the odontoid. One-way analysis of variance with the Tukey test was used to analyze the parameters among the groups, while the t-test was used to analyze gender differences. Correlations between parameters and age were assessed using Pearson's test.

Results

There were significant differences between male and female subjects in screw length and inner and outer diameters (of both sagittal and coronal views) but not in screw angle. The narrowest diameter of the odontoid was 4.0 ± 1.5 mm in the youth group, 5.5 ± 1.5 mm in the juvenile group, and 5.6 ± 1.1 mm in the adolescent group, respectively. There were significant differences among the three groups in screw length (p < 0.0001). The screw angle of the adolescent group was significantly smaller than that of the youth and juvenile groups. More than 90% of children aged 7–18 years old had an odontoid diameter greater than 4 mm, while only half of the youth group had an odontoid with diameter >4 mm. Screw length and inner and outer diameters in lateral view were positively correlated with age, and screw angle was negatively correlated with age.

Conclusion

It is feasible to insert a standard single screw (Φ 3.5 mm) into the odontoid of children aged 7–18 years old but not those aged 2–6 years old. How the anatomical parameters of the odontoid change with age, especially the narrowest diameters, is worthy of attention.     

C2椎弓根螺钉内固定术治疗Hangman骨折的生物力学评价

目的 测试C2椎弓根螺钉内固定术治疗各型Hangman骨折的生物力学性能并探讨其手术适应证。方法 6具新鲜C1～C4颈椎标本依次制成Ⅰ型、ⅡA型和Ⅱ型Hangman骨折模型,按照：①正常;②Ⅰ型骨折C2椎弓根螺钉固定;③ⅡA型骨折G椎弓根螺钉固定;④Ⅱ型骨折C2椎弓根螺钉固定。顺序测试三维运动范围并进行比较。结果 Ⅰ型～Ⅱ型骨折椎弓根钉固定前后有显著性差异,有即时稳定作用。Ⅰ型骨折C2椎弓根螺钉固定后ROM值与对照组无显著性差异,且相对稳定性在屈曲、后伸、侧弯及旋转达到了对照组的100．62％、96．91％、99．19％、97．12％。ⅡA型骨折C2椎弓根螺钉固定后除旋转外与对照组无显著性差异;旋转稳定性也达到了对照组的61．86％。而Ⅱ型骨折C2椎弓根螺钉固定后与对照组比有显著性差异,相对稳定性在屈曲、后伸、侧弯及旋转只有对照组的47．84％、21．29％、65．98％、41．69％。三种骨折椎弓根钉固定后相比Ⅱ型骨折固定组与Ⅰ型、ⅡA型骨折固定组有显著性差异,稳定性最差;Ⅰ型、ⅡA型骨折固定组之间除旋转外无显著性差异,ⅡA型骨折固定组旋转稳定性稍差。结论 Ⅰ型骨折固定后达到了生理性固定;ⅡA型骨折固定后稳定性较好,基本适合C2椎弓根螺钉治疗;Ⅱ型骨折固定后稳定性较差,不适合单纯椎弓根钉内固定。     

解剖型锁定钢板内固定治疗肱骨远端C型骨折

目的探讨应用解剖型锁定钢板内固定治疗C型肱骨远端骨折的疗效。方法肱骨远端C型骨折28例,按AO/ASIF分类:C1型10例,C2型15例,C3型3例;均采用采用尺骨鹰嘴截骨入路,解剖型锁定钢板内固定。受伤至手术时间平均5.8 d(2 h~10 d)。结果术后28例均获随访,平均20(2~30)月。骨折愈合时间平均3.5(2~10)个月。根据Cassebaum评分系统评定肘关节功能:优10例,良12例,可5例,差1例,优良率为78.6%,结论采用尺骨鹰嘴截骨入路,早期切开解剖复位、解剖型钢板内固定及早期有计划地康复训练治疗肱骨远端骨折,复位良好,固定可靠,能最大限度地恢复肘关节功能。     

锁定钢板外置与外固定支架固定骨折的生物力学研究

目的 通过对锁定钢板(LCP)外置与外固定支架固定骨折进行生物力学分析,为应用锁定钢板外置固定治疗提供理论依据。方法 选择不同长度的牛小腿骨,制备成骨折标本,分别采用锁定钢板外置固定和外固定支架固定,观察标本在不同载荷下承受的轴向压缩、扭转和弯曲位移。结果 两组在100、200、300、400、500、600和700 N载荷下轴向压缩值比较,均有显著差异(P<0.05),且随着载荷越大轴向压缩值差距越大。两组在4、6、8、10、12和14 N.cm载荷下扭转角度比较,差异均有统计学意义(P<0.05),且随着载荷越大则扭转角度值差距越大。两组在50、100、150、200、250和300 N载荷下弯曲位移值比较,差异均有统计学意义(P<0.05),且随着载荷越大弯曲位移值差距越大。结论 锁定钢板外置固定骨折在生物力学性能上优于外固定支架,可在临床应用,为治疗开放性骨折提供了一种新的方法。     

Medial Locking Plate Versus Screw Fixation for Fixation of the Ludloff Osteotomy

A prospective cohort study of the Ludloff osteotomy, stabilized with either lag screws or a locking plate, was undertaken from May 2001 to November 2010, involving patients treated for hallux valgus with a first intermetatarsal angle greater than 15°. All patients were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) and Roles and Maudsley scores before and after surgery. The cohort included 119 procedures in 112 patients, 91 (76.47%) of which were fixated with lag screws and 28 (23.53%) with locking plates. The participants were categorized as active (n = 69 procedures) or athletic (n = 50 procedures). The overall mean patient age was 45.5 ± 14.2 years. No statistically significant differences were found between the fixation groups relative to age, preoperative AOFAS and Roles and Maudsley scores, and postoperative AOFAS scores. Postoperatively, the mean Roles and Maudsley score for the lag screw group was 1.8 ± 0.6 and that for the locking plate group was 2.2 ± 0.7 (p < .009). In both groups, the AOFAS scores improved significantly (p < .0001) after surgery. The mean interval to return to activity in the athletes was 3.6 ± 1.1 months and was 3.9 ± 1.2 weeks in the active group (p = .16). Also, 4 of the active patients (5.8%) failed to return to their desired activity level. Overall, 6 (5%) recurrent hallux valgus deformities were observed, 5 (4.2%) in the lag screw group and 1 (.8%) in the locking plate group (p = .57). Of the 6 recurrences, 5 occurred (4.2%) in patients older than 50 years (p = .05).     

Biomechanical Comparison of a Locking Plate with Intraplate Compression Screw Versus Locking Plate with Plantar Interfragmentary Screw for Lapidus Arthrodesis: A Cadaveric Study

Lapidus arthrodesis (first metatarsal cuneiform arthrodesis) has become an accepted procedure for hallux abducto valgus. Several variations of fixation have been described. Earlier weightbearing postoperatively has been one reported benefit of using locking plates for fixation. Additionally, studies have demonstrated that fixation placed on the plantar or tension side of the arthrodesis increases the biomechanical advantage. We performed a biomechanical cadaveric study of the Lapidus procedure, comparing a previously reported technique using a low profile locking plate with an intraplate compression screw versus the same locking plate with a plantar interfragmentary screw (PIFS) placed on the tension side of the arthrodesis in 10 fresh, paired, cadaver limbs. The mean ultimate load of the plate with a PIFS was 383.2 ± 211.5 N, and the mean ultimate load of the plate with an intraplate compression screw was 205.5 ± 97.2 N. The mean ultimate load of the LPS Lapidus plate with a PIFS was statistically greater (p = .027) than that with the plate intraplate compression screw. Our results indicated that changing the orientation of the compression screw to a PIFS significantly increased the stability of the Lapidus arthrodesis fixation construct. The modified construct with the PIFS might decrease the incidence of nonunion and, ultimately, allow patients to bear weight faster postoperatively.     

Biomechanical Comparison of Locking Plate and Cancellous Screw Techniques in Medial Malleolar Fractures: A Finite Element Analysis

As the commonly used fixation strategy of medial malleolar fractures, cancellous screws (CS) have been challenged for instability, bone destruction, and metal prominence. It is still unclear whether a locking compression plate (LCP) is a better choice in such fractures. Our purpose is to compare the mechanical efficacy of LCP with traditional 4.0-mm CS for transverse, oblique, and vertical medial malleolar fractures by using finite element analysis. In this study, 3-dimensional models of the distal tibia were reconstructed from a computed tomography scan of a young healthy male adult. Conditions included 3 fracture lines at 30°, 60°, and 90°; 2 groups of fixation (LCP and CS); and 3 adduction loads of 300, 500, and 700 N applied to the medial malleolar joint surface. The proximal part of the tibia was fixed for all degrees of freedom. The fracture displacements of the LCP were smaller than those of CS (p < .05). The stiffness of the LCP constructs was much higher than that of the CS constructs, especially in the 90° fractures (490.3 versus 163.6 N/mm). The mean stress around the CS was higher than that in LCP for 60° and 90° fractures, but there was no difference for 30°. Maximal bone stress increased (19.84 to 50.86 MPa) and concentrated on cortical bone in LCP, whereas it concentrated on cancellous bone in CS. The results showed that LCP could improve stability, preventing bone destruction in oblique and vertical medial malleolar fractures. However, in transverse fractures, CS provides sufficient stability, with no need to use LCP.     

Bicortical Screw Fixation of Distal Fibula Fractures With a Lateral Plate: An Anatomic and Biomechanical Study of a New Technique

One of the potential drawbacks of lateral plating of distal fibula fractures is less than satisfactory fixation of unicortical screws commonly placed in the distal fragment to avoid implant penetration of the ankle joint. This study examines the anatomy of the distal fibula, proposes new techniques for bicortical screw fixation and radiographic evaluation of screw placement, and compares pullout strength of unicortical versus bicortical screws in this area. Sixteen pairs of human cadaver feet were used in this study. It was found that a large percentage of the surface area of the distal fibula is nonarticular and that the distal fibula could be divided into 3 zones with distinct anatomic features. Zone I is defined as the distal most 1.5 cm of the fibula, zone II is the next 1 cm of fibula proximal to zone I, and zone III is defined as the fibula above the ankle joint, starting at just over 2.5 cm proximal to the tip of the fibula. We determined a safe corridor for bicortical screw placement by means of a lateral plate in each zone. An improved radiographic view is described for confirmation of extraarticular screw placement. Screw pullout testing was performed on 8 pairs of fresh-frozen human cadaver fibulas. In both zone I and zone II, the bicortical screw fixation was significantly stronger than the unicortical screw fixation. In zone I, the average pullout strength for the bicortical screw fixation was 2.3 times higher than the unicortical screw fixation. In zone II, the average pullout strength for the bicortical screw fixation was 3.3 times higher than the unicortical screw fixation. This study shows that not only is bicortical screw placement in the distal fibula technically feasible, but it is also biomechanically stronger than unicortical placement in this area.