Dynamic locking plates provide symmetric axial dynamization to stimulate fracture healing

Axial dynamization of an osteosynthesis construct can promote fracture healing. This biomechanical study evaluated a novel dynamic locking plate that derives symmetric axial dynamization by elastic suspension of locking holes within the plate. Standard locked and dynamic plating constructs were tested in a diaphyseal bridge‐plating model of the femoral diaphysis to determine the amount and symmetry of interfragmentary motion under axial loading, and to assess construct stiffness under axial loading, torsion, and bending. Subsequently, constructs were loaded until failure to determine construct strength and failure modes. Finally, strength tests were repeated in osteoporotic bone surrogates. One body‐weight axial loading of standard locked constructs produced asymmetric interfragmentary motion that was over three times smaller at the near cortex (0.1 ± 0.01 mm) than at the far cortex (0.32 ± 0.02 mm). Compared to standard locked constructs, dynamic plating constructs enhanced motion by 0.32 mm at the near cortex and by 0.33 mm at the far cortex and yielded a 77% lower axial stiffness (p < 0.001). Dynamic plating constructs were at least as strong as standard locked constructs under all test conditions. In conclusion, dynamic locking plates symmetrically enhance interfragmentary motion, deliver controlled axial dynamization, and are at least comparable in strength to standard locked constructs. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1218–1225, 2015.     

Acute Proximal Row Carpectomy after Complex Carpal Fracture Dislocation

Acute proximal row carpectomy is an uncommon definitive treatment for perilunate fracture dislocations. In this report, we present five patients who had acute proximal row carpectomy (PRC) to treat perilunate fracture-dislocations. All patients were men between ages 31 and 87. The indication for PRC was lunate fracture in two patients, concomitant displaced scaphoid fracture and scapholunate ligament injury in two patients, and perilunate fracture-dislocation with preexisting articular damage from long-standing gout in one patient. At the final follow-up ranged from 4.5 month to 7.5 years, four patients had no pain and one patient was lost to follow-up. One patient had a concomitant PRC and a bridging plate that was never removed. The remaining three patients gained satisfactory range of motion. Our observation reveals that acute proximal row carpectomy is an option for some patients with complex carpal fracture dislocations, particularly those with fracture of the lunate, concomitant scaphoid fracture and scapholunate ligament injury, or preexisting wrist arthritis.     

Non-union of calcaneum – A rare complication of calcaneal fracture – A case report with brief review of literature

Intra-articular fractures of calcaneum are known to be difficult to manage and lead to multiple complications including subtalar arthritis and malunion. However, non-union of calcaneum is rarely encountered. Only a total of six studies reporting on 12 patients could be found on reviewing the available literature (English language only). One such case of non-union of calcaneal fracture and its successful management is being reported in this case report. In addition, extremely limited literature available on calcaneal non-union is also briefly reviewed. Role of subtalar arthrodesis with internal fixation of fracture and bone grafting for successful management of this rare complication is highlighted along with the possibility of under-reporting of this relatively unknown complication.     

Bone Cement Dislodgement: One of Complications Following Bone Cement Augmentation Procedures for Osteoporotic Spinal Fracture

Bone cement augmentation procedures have been getting more position as a minimally invasive surgical option for osteoporotic spinal fractures. However, complications related to these procedures have been increasingly reported. We describe a case of bone cement dislodgement following cement augmentation procedure for osteoporotic spinal fracture by reviewing the patient''s medical records, imaging results and related literatures. A 73-year-old woman suffering back and buttock pain following a fall from level ground was diagnosed as an osteoporotic fracture of the 11th thoracic spine. Percutaneous kyphoplasty was performed for this lesion. Six weeks later, the patient complained of a recurrence of back and buttock pain. Radiologic images revealed superior dislodgement of bone cement through the 11th thoracic superior endplate with destruction of the lower part of the 10th thoracic spine. Staged anterior and posterior fusion was performed. Two years postoperatively, the patient carries on with her daily living without any significant disability. Delayed bone cement dislodgement can occur as one of complications following bone cement augmentation procedure for osteoporotic spinal fracture. It might be related to the presence of intravertebral cleft, lack of interdigitation of bone cement with the surrounding trabeculae, and possible damage of endplate during ballooning procedure.     

经皮椎体后凸成形术与传统开放手术对邻近腰椎生物力学功能影响的比较

目的 观察在兔骨质疏松模型中行经皮椎体后凸成形术(PKP)和开放复位内固定手术对邻近腰椎生物力学功能的影响.方法 将新西兰大白兔通过切除双侧卵巢建立骨质疏松模型,造模成功42只,分为两组,A组21只,予以行开放复位内固定手术;B组21只,予以PKP手术,观察两组模型术后椎体弯曲和压缩实验最大载荷量的变化,椎体术后平均高度和矢状面Cobb角的改变.结果 两组兔模型行PKP和开放复位内固定术术后椎体承载压力能力得到了显著提升,手术前差异有统计学意义(P＜0.01),B组术后椎体承载压力能力提高较A组明显,其差异有统计学意义(P＜0.05).但术后6、12、18个月两组模型承载压力能力逐渐下降.术后观察18个月,A组手术椎体术后平均高度和矢状面Cobb角均无明显变化,B组模型18个月后手术椎体前缘平均高度由术前(38.81±4.12)％恢复至(80.17±8.38)％,矢状面Cobb角由术前(30.13±4.27)°恢复至(8.69±2.41)°.B组椎体术后高度测量值和Cobb角的变化与A组比较,差异有统计学意义(P＜0.05).结论 PKP较开放复位内固定手术可更好地改善邻近椎体后凸角度,更显著地改善椎体承载压力的能力,PKP治疗骨质疏松安全有效.     

后路板-棒内固定系统治疗不稳定性寰椎骨折的生物力学研究

目的 :测试后路板-棒内固定系统治疗不稳定寰椎骨折的稳定性,为临床使用提供理论基础。方法 :采集新鲜成年人尸体颈椎骨(C0~C3)标本6具,用聚甲基丙烯酸甲酯(PMMA)上下包埋,在生物力学实验机上,以150N为最大生理载荷,最大力矩为1.50N·m,依次测量完整模型组(A组)、骨折模型组(B组,包括寰椎后弓两处骨折与典型Jefferson骨折,分别作为B1组和B2组,骨折模型制作时保持横韧带完整)、内固定模型组(C组,包括B1组+内固定系统、B2组+内固定系统,分别作为C1组、C2组)C0-C1、C1-C2节段前屈/后伸、左/右侧屈和左/右旋转等6个方向的三维运动范围(ROM),通过比较,评价后路板-棒内固定系统治疗寰椎骨折的生物力学稳定性。根据测量所得ROM值,设A组各方向三维运动稳定性指数(Sf)为100%,计算B组、C组模型各运动方向Sf,进一步直观比较各模型的稳定性变化。结果:C0-C1节段,A组前屈/后伸、左右侧屈、左右轴向旋转方向的ROM分别为11.06°±1.00°,7.08°±0.62°,13.24°±1.24°;B1、B2组前屈/后伸、左右侧屈、左右轴向旋转方向ROM均较A组明显增大(P0.05);C1组前屈/后伸、左右侧屈、左右旋转方向的ROM均较B1组明显减小(P0.05);C2组各方向ROM均较B2组明显减小(P0.05);C1、C2组前屈/后伸、左右侧屈、左右轴向旋转方向ROM与A组比较均无统计学差异(P0.05)。C1-C2节段,A组前屈/后伸、左右侧屈、左右轴向旋转方向的ROM分别为10.07°±1.12°,5.56°±0.54°,20.83°±2.12°;B1、B2组各方向ROM均较A组明显增大(P0.05);C1组各方向的ROM较B1组明显减小(P0.05);C2组各方向ROM较B2组明显减小(P0.05);C1、C2组各方向ROM与A组比较均无统计学差异(P0.05)。C0-C1节段,B1组前屈/后伸、左/右侧屈、左/右轴向旋转方向Sf分别为71%、70%、64%,B2组各方向Sf分别为61%、55%、58%,C1组各方向Sf分别为102%、108%、108%,C2组各方向Sf分别为91%、91%、92%。C1-C2节段,B1组前屈/后伸、左/右侧屈、左/右轴向旋转方向Sf分别为70%、61%、35%,B2组各方向Sf分别为59%、54%、37%,C1组各方向Sf分别为105%、111%、106%,C2组各方向Sf分别为91%、90%、92%。结论:寰椎后路板-棒内固定系统既能恢复上颈椎稳定性,又可保留其生理运动功能。使用该系统治疗寰椎后弓两处骨折,在稳定性方面效果稍优于典型Jefferson骨折。     

锁骨近端骨折治疗进展

锁骨近端骨折发病率极低,一般行保守治疗。对于须行手术治疗的患者,因该处解剖结构比较特殊,并缺乏特定内固定材料,稳妥固定难度较大,临床上一直在探索一种比较好的内固定方式。我们对锁骨近端骨折的治疗进展进行综述。     

改良后外侧入路治疗胫骨平台后外侧骨折23例

目的探讨改良后外侧入路治疗胫骨平台后外侧骨折的临床疗效。方法对23例胫骨平台后外侧骨折患者行后外侧入路行支撑钢板内固定治疗。结果 23例均获随访,时间8~19个月。骨折均愈合,愈合时间9~16周。HSS膝关节评分67~96分。结论改良后外侧入路手术治疗胫骨平台后外侧骨折,有利于骨折的复位和固定,具有暴露清楚、内固定安放方便、创伤小及临床疗效好等优点。     

颈椎后路手术治疗齿状突骨折及其邻近节段损伤疗效分析

目的探讨颈椎后路手术治疗齿状突骨折及其邻近节段损伤的临床疗效。方法 2009-08-2013-08 21例齿状突及其邻近节段骨折脱位在我院行颈椎后路手术治疗患者。21例均采用上颈椎后路个性化的固定方式。随访观察患者临床症状和神经功能改善情况,对有脊髓损伤的患者,术前、术后6个月进行JOA评分,术后随访影像学资料评价骨折愈合、植骨融合等情况。结果所有病例术后均获得随访,平均随访时间18个月(12~48个月),术中未出现脊髓、椎动脉损伤等严重并发症。术后6个月临床症状得到明显改善,X线片示螺钉位置良好,无松动、断钉,所有骨折均呈骨性愈合。9例不完全性脊髓损伤患者术后脊髓神经功能ASIA分级均较术前提高,脊髓功能均获不同程度改善。JOA评分从术前平均(11.4-2.6)分提高至术后6个月平均(15.1-2.9)分,术前术后比较有统计学差异,平均改善率为(85.3%±8.3%),优良率95%。结论选择合理的颈椎后路手术方式,在治疗齿状突骨折及其邻近节段损伤中,能取得良好的疗效。     

胸腰椎爆裂性骨折短节段伤椎固定三维有限元模型构建及生物力学比较研究

[目的]建立胸腰椎爆裂性骨折后路不同固定方式的尸体标本和三维有限元模型,比较不同固定方式的生物力学特点,优化手术方式选择。[方法]6具20~40岁青壮年胸腰椎(T11~L3)标本,压缩法制作L1椎体爆裂性骨折模型。平均分成3组,分别行后路长节段固定、常规短节段固定和伤椎短节段固定的手术固定方式,三维运动试验机检测标本在10 N·m力矩下前屈、后伸、侧屈和旋转4个方位的运动范围(ROM),材料机评估标本在500 N压力下的轴向压缩刚度。另取1具尸体为正常胸腰椎模型,借助CT扫描和有限元软件,模拟L1节段爆裂性骨折生成三种不同手术固定方式的有限元模型,施加相应载荷,分析各模型的应力分布,比较并进一步验证力学分析结果。[结果]生物力学证明,后路长节段固定、短节段固定和伤椎短节段固定后的胸腰段爆裂性骨折模型的ROM值和轴向压缩刚度组间差异无统计学意义。三维有限元应力分布显示,常规短节段和经伤椎短节段固定在T12平面的应力显著小于后路长节段固定方式。[结论]三种手术固定方式均能达到T11~L3节段的稳定,但后路常规短节段固定和经伤椎短节段固定更易于对伤椎的保护,经伤椎短节段固定具有更高的稳定性。