矩形髓内钉治疗胫腓骨骨折的生物力学研究

为进一步探讨矩形髓内钉良好疗效的生物力学机制，设计本实验研究。１２例２４根人体胫骨标本分为两组，以同一人体左右侧作自身对照。实验组行矩形髓内钉固定，对照组行Ｅｎｄｅｒ钉固定。其中６对标本行扭转试验，测量扭转变形位移及扭角值，描绘扭矩－－扭角曲线，并计算扭转刚度，结果进行统计学处理（ｔ检验）。其余６对标本按内→外、外→内、前→后、后→前四个方向，行三点弯曲试验，测量变曲负载、角位５移值，数据处理同前     

股骨型髓内分叉钉的生物力学研究与临床应用

目的　研究新型股骨型髓内分叉钉治疗股骨下段骨折的生物力学特性。方法　将 36根成人股骨尸骨标本随机分为三组 ,并在股骨的下 1/ 4处锯断 ,做成股骨中下段横型骨折的模型 ;分别用股骨型髓内分叉钉、Ender钉和梅花钉固定 ;然后各组分别进行抗扭、抗弯和抗拉生物力学实验。结果　股骨型髓内分叉钉的抗扭、抗弯和抗拉性能明显优于Ender钉和梅花钉。髓内分叉钉的扭强度是Ender钉和梅花钉的 2 8倍和 4 4倍 ,抗扭刚度系数α也明显高于Ender钉和梅花钉 (P <0 0 1) ;抗弯强度是Ender钉和梅花钉的 2 3倍和 1 4倍 ,抗弯刚度系数 β也明显高于Ender钉和梅花钉 (P <0 0 1) ;髓内分叉钉的抗拉强度随位移的增加而逐渐增大 ;当位移达到 5mm时 ,抗拉强度是Ender钉和梅花钉的 1 7倍和 4 5倍。结论　髓内分叉钉的设计符合股骨下段解剖特点 ,具有良好的生物力学性能 ,股骨型髓内分叉钉是一种治疗股骨骨折的新型髓内固定器械     

胫骨型髓内分叉钉治疗胫骨骨折的生物力学研究

目的：对胫骨型髓内分叉钉（TITN）内固定胫骨骨折的生物力学性能进行实验研究,为临床应用提供理论依据。方法：采用36根湿尸体胫骨标本进行实验,比较TITN与矩形钉,Ender钉及梅花钉固定之胫骨骨折在抗扭转、抗弯曲和抗轴向拉伸刚度等方面差异性。结果：扭转试验、弯曲试验及轴向拉伸试验结果均表明TITN的抗扭、抗弯、抗轴向拉伸刚度均优于矩形钉、Ender钉、梅花钉（P＜0.05）。结论：TITN有良好的生物力学性能,有较强的骨折固定作用和稳定性,尤其在抗旋转和抗拉性能方面。     

胫骨型髓内分叉钉治疗胫骨骨折的生物力学研究

目的　对胫骨型髓内分叉钉 (TITN)内固定胫骨骨折的生物力学性能进行实验研究 ,为临床应用提供理论依据。方法　采用 36根湿尸体胫骨标本进行实验 ,比较TITN与矩形钉 ,Ender钉及梅花钉固定之胫骨骨折在抗扭转、抗弯曲和抗轴向拉伸刚度等方面差异性。结果　扭转试验、弯曲试验及轴向拉伸试验结果均表明TITN的抗扭、抗弯、抗轴向拉伸刚度均优于矩形钉、Ender钉、梅花钉 (P <0 0 5 )。结论　TITN有良好的生物力学性能 ,有较强的骨折固定作用和稳定性 ,尤其在抗旋转和抗拉性能方面     

股骨型髓内分叉钉的生物力学研究与临床应用

目的 研究新型股骨型髓内分叉钉治疗股骨下段骨折的生物力学特征。方法 将36根成人股骨尸骨标本随机分为三组，并在股骨的下1／4处锯断，做成股骨中下段模型骨折的模型；分别用股骨型髓内分叉钉、Ender钉和梅花钉固定；然后各组分别进行抗钮、抗弯和抗拉生物力学实验。结果 股骨型髓内分叉钉的抗钮、抗弯和抗拉性能明显优于Ender钉和梅花钉。髓内分叉钉的扭强度是Ender钉和梅花钉的2．8倍和4．4倍，抗扭刚度系数α也明显高于Ender钉和梅花钉（P＜0.01)；抗弯强度是Ender钉和梅花钉的2．3倍和1．4倍，抗弯刚度系数β也明显高于Ender钉和梅花钉（P＜0.01)；髓内分叉钉的抗拉强度随位移的增加而逐渐增大；当位移达到5mm时，抗拉强度是Ender钉和梅花钉的1．7倍和4．5倍。结论 髓内分叉钉的设计符合股骨下段解剖特点，具有良好的生物力学性能，股骨型髓内分叉钉是一种治疗股骨骨折的新型髓内固定器械。     

分叉交锁髓内钉和其它三种内固定器材治疗肱骨骨折的生物力学比较研究

目的　对分叉交锁髓内钉 (BLIN)内固定肱骨骨折的生物力学性能进行实验研究 ,为临床应用提供可靠的理论依据。方法　采用 18根湿润新鲜肱骨标本进行实验 ,比较分叉交锁髓内钉与其它三种内固定物固定之肱骨骨折在抗轴向拉伸及压缩、抗弯曲、抗扭转的强度和刚度等方面的差异性。结果　在拉伸和压缩试验中 ,BLIN固定之肱骨骨折具有近于两端均行横向交锁之髓内钉 (TLIN)的相对高的破坏载荷 ,而刚度相对较低 ;BLIN的抗扭转、抗弯曲性能强于 6孔加压钢板 (6TCP)。三根Ender钉内固定 (E3)各项生物力学性能均为最差。结论　BLIN属坚强内固定和弹性动态固定的有机组合 ,应力遮挡率低 ,有利于术后早期活动和骨折愈合。     

胫骨髓腔形态学测量与解剖型胫骨弹性髓内钉的设计

目的在研究胫骨髓腔解剖的基础上设计一种解剖型胫骨弹性髓内钉,并测量其生物力学性能.方法选择35枚成人胫骨标本,根据X线片测量结果获得髓内钉的腰段长度、前锥度、后锥度、弧度等形态参数,制作髓内钉,并在胫骨中段骨折模型上进行生物力学测试,比较其抗弯,抗扭转性能.结果解剖型弹性髓内钉固定胫骨干骨折的抗弯能力是矩形髓内钉的1.8倍和1.5倍.抗扭转能力是其1.6倍.结论胫骨解剖型弹性髓内钉是一种更复合胫骨骨折内固定的弹性髓内钉.     

解剖型矩形髓内钉的生物力学评价及临床应用初步报告

目的：为进一步完善矩形髓内钉在胫骨骨折中的应用,克服其操作时容易交叉,对胫骨上段骨折固定力学性能较差等不足,作者设计了胫骨解剖型可屈性矩形髓内钉,并将其与原矩形髓内钉进行生物力学比较后初步应用于临床。方法：将新鲜成人胫骨标本制造胫骨上１／３ 与中１／２ 横断骨折模型,分别用２ 种矩形髓内钉进行固定,并进行生物力学测试。结果：对胫骨上１／３ 骨折,解剖型矩形髓内钉的抗弯能力是普通矩形髓内钉的２－５ 倍（ 冠状面） 和４－３ 倍（ 矢状面） ,抗扭能力是后者的３－９ 倍;对胫骨中段骨折,解剖型矩形髓内钉的抗弯能力是后者的１－８ 倍（ 冠状面） 和１－５ 倍（ 矢状面） ,抗扭能力为１－６ 倍。结论：解剖型矩形髓内钉是在研究胫骨髓腔解剖学特点基础上进行设计的,其生物力学特性优良,初步临床应用已取得了较好效果,值得进一步推广。     

改良梅花型交锁髓内钉固定股骨粗隆下骨折的生物力学研究

目的比较自行设计的改良梅花型交锁髓内钉与国产Gamma钉固定股骨粗隆下骨折的即刻生物力学特性,探讨改良梅花型交锁髓内钉固定股骨粗隆下骨折的可行性。方法 8具成年健康男性股骨标本,按左右侧分为实验组和对照组,分别制作股骨粗隆下横形骨折模型。实验组采用长度350 mm的改良梅花型交锁髓内钉固定骨折,对照组采用长度350 mm国产Gamma钉固定骨折。分别检测抗轴向压缩、抗侧弯及抗扭转力学性能,并进行统计学分析。结果 1 000 N轴向载荷压力下的抗压刚度、1 000 N压力下的抗弯曲刚度及3 N/m下的抗扭转刚度:对照组分别为(2 359.4±200.8)N/mm、(614.7±60.2)N/m、(0.64±0.16)Nm/°,实验组分别为(2 178.1±129.5)N/mm、(439.1±48.2)N/m、(0.48±0.13)Nm/°。两组抗压、抗弯曲、抗扭转3项指标比较差异均无统计学意义(P>0.05)。结论改良梅花型交锁髓内钉具有较好的生物力学性能,可用于内固定治疗股骨粗隆下横形骨折。     

新型串孔型髓内钉的研发与静态力学研究

目的:研究开发新型串孔型胫骨髓内钉,并对其进行静态力学测试.方法:分实验组和对照组两组,实验组利用新型钛合金TAMZ为原料,制造9mm胫骨串孔型髓内钉9根,对照组选用9mm国产不锈钢胫骨髓内针9根,分别将髓内钉安装在自行设计的模型中,测试其压缩、弯曲和扭转力学特性.结果:两组抗压缩能力上无统计学差异,实验组有更好的扭转刚度,实验组的主钉弯曲强度高于对照组,但缩孔处强度低于对照组.结论:新型髓内钉不但在结构上有所改进,将大大方便临床使用,而且在力学上完全能够满足临床要求.     

趾甲原位覆盖技术在治疗甲床破裂创面中的应用

目的探讨趾甲覆盖技术在治疗足趾甲床破裂创面中的应用。方法应用趾甲覆盖技术治疗甲床破裂患者54例(66趾)。结果术后随访2周～8个月,依据伤趾修复评定标准,优62趾,良2趾,差2趾,总体优良率达97%。结论趾甲覆盖技术能最大限度地恢复趾甲形态,修复趾甲损伤,简便可靠,值得推广。     

Femoral lengthening in young patients: An evidence-based comparison between motorized lengthening nails and external fixation

BACKGROUNDFemoral lengthening is a procedure of great importance in the treatment of congenital and acquired limb deficiencies. Technological advances have led to the latest designs of fully implantable motorized intramedullary lengthening nails. The use of these nails has increased over the last few years.AIMTo review and critically appraise the literature comparing the outcome of femoral lengthening in children using intramedullary motorized lengthening nails to external fixation.METHODSElectronic databases (MEDLINE, CINAHL, EMBASE, Cochrane) were systematically searched in November 2019 for studies comparing the outcome of femoral lengthening in children using magnetic lengthening nails and external fixation. The outcomes included amount of gained length, healing index, complications and patient reported outcomes.RESULTSOf the 452 identified studies, only two (retrospective and non-randomized) met the inclusion criteria. A total of 91 femora were included. In both studies, the age of patients treated with nails ranged from 15 to 21 years compared to 9 to 15 years for patients in the external fixation group. Both devices achieved the target length. Prevalence of adverse events was less in the nail (60%-73%) than in the external fixation (81%-100%) group. None of the studies presented patient reported outcomes.CONCLUSIONThe clinical effectiveness of motorized nails is equivalent or superior to external fixation for femoral lengthening in young patients. The available literature is limited and does not provide evidence on patient quality of life or cost effectiveness of the interventions.     

"Failure" of forearm intramedullary elastic nails

Elastic nails are an established modality for treating forearm fractures in children. These nails are usually removed 6–9 months after surgery as refracture may occur in 10% of cases if the nails removed earlier. We report a case of refracture of the forearm bones with elastic nails in situ, 5 months after the original fractures. The fracture was angulated approximately 80° with the apex pointing anteriorly. Closed reduction was difficult and resulted in breakage of the ulnar nail. The authors describe the details and outline the management of this unreported complication.     

Titanium elastic nails for pediatric tibial shaft fractures

Purpose  The purpose of our study was to investigate the safety and efficacy of elastic stable intramedullary nailing for unstable pediatric tibial shaft fractures using titanium elastic nails (TENs). To our knowledge, this is the largest series reported in the literature of this specific fixation technique. Methods  We reviewed all children with tibial shaft fractures treated operatively at our tertiary care children's hospital to find those patients who underwent fixation with TENs. Between 1998 and 2005, we identified 19 consecutive patients who satisfied inclusion criteria. The average age of the patients in our series was 12.2 years (range 7.2–16 years), and mean follow-up was 15.7 months (range 6–28 months). Patient charts and radiographs were retrospectively reviewed to gather the clinical data. Outcomes were classified as excellent, satisfactory, or poor according to the Flynn classification for flexible nail fixation. Results  All patients achieved complete healing at a mean of 11.0 weeks (range 6–18 weeks). At final follow-up, mean angulation was 2° (range 0°–6°) in the sagittal plane and 3° in the coronal plane (range 0°–9°). Five patients (26%) complained of irritation at the nail entry site; there were no leg length discrepancies or physeal arrests as a result of treatment. Two patients required remanipulation after the index procedure to maintain adequate alignment. According to the Flynn classification, we had 12 excellent, six satisfactory, and one poor result. Conclusion  Although the indications for operative fixation of pediatric tibial shaft fractures are rare, occasionally surgical treatment is warranted. Based on our results, elastic stable intramedullary nailing with titanium elastic nails is an effective surgical technique which allows rapid healing of tibial shaft fractures with an acceptable rate of complications. No authors received any financial support or compensation for this study.     

Limb lengthening over a nail can safely reduce the duration of external fixation

Background:

Limb lengthening using Ilizarov external fixation is safe, but the consolidation phase tends to take too long. A method that can safely reduce the time spent in external fixation would help increase patient tolerance and comfort. We report our results of lengthening over nails (LON) method in which an interlocking nail was used along with an Ilizarov external fixator to reduce external fixation duration in limb lengthening. This is a retrospective study.

Materials and Methods:

Twenty-seven lengthening surgeries were done with the LON method in 23 patients with 22 tibiae and five femora during the last 12 years. Length gain ranged from 1.5 cm to a maximum of 9.8 cm with a mean of 4.6 cm. The mean modified Paley difficulty score was 7.6 points. Fourteen associated procedures were performed in these patients, including equinus contracture releases, supracondylar osteotomies, ilizarov hip reonstruction and ankle fusion. We had a 29% rate of complications which included one problem, three obstacles and four complications with no serious deep intramedullary infections. Our rate of complications compares favorably with series reported in the literature. External fixation duration was reduced significantly to a mean of 17.8 days per cm.

Conclusions:

A combination of intramedullary nailing along with external fixation significantly reduces external fixation time while maintaining low rate of complications. Great care needs to be taken to prevent pin track infection and deep intramedullary sepsis.     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately.     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately.     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately.     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately.     

下颈椎经关节螺钉联合侧块或椎弓根螺钉固定的效果

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately.