Mechanical comparison of a distal femoral side plate and a retrograde intramedullary nail

OBJECTIVE: To compare quantitatively the axial and torsional stiffness of a retrograde intramedullary nail and a fixed angle screw side plate in treating a supracondylar femur fracture in osteopenic femora. To determine the modes of failure of an intramedullary nail and a side plate under axial loading. DESIGN: Matched pair cadaveric study. SETTING: Orthopaedic biomechanics laboratory. PATIENTS AND OTHER PARTICIPANTS: Eleven matched pairs of preserved human femora were selected. The cadaveric specimens were harvested from relatively elderly donors with an average age of 75.6 years, which represents the principal population at risk for poor fracture fixation. INTERVENTION: The eleven matched pairs were osteotomized to simulate segmental structural defects in the supracondylar region. One femur of each matched pair was fixed with an intramedullary nail, and the contralateral femur was fixed with a side plate. MAIN OUTCOME MEASURES: Axial and torsional stiffness values. Axial modes of failure. RESULTS: The intramedullary nail axial stiffness was 14 percent (p = 0.04) less and torsional stiffness was 17 percent (p = 0.05) less than that provided by the side plate. The axial failure of the intramedullary nail occurred distally, allowing the hardware to protrude into the articular space. The side plate also failed distally by displacing the condylar screw into a varus angulation. CONCLUSION: The mechanical advantages favor the use of the side plate if fixation stiffness is essential. The axial mode of failure occurs distally for both fixation devices.     

Biomechanical analysis of antegrade and retrograde flexible intramedullary nail fixation of pediatric femoral fractures using a synthetic bone model

Biomechanical testing was performed to evaluate the stability of simulated transverse and comminuted femoral fractures after retrograde and antegrade flexible titanium intramedullary nail fixation. Ten synthetic adolescent-sized femoral bone models were used. Five underwent retrograde fixation with two C-shaped nails inserted from medial and lateral entry portals. The other five underwent antegrade fixation using one C- and one S-shaped nail through lateral entry holes just inferior to the greater trochanter. Retrograde nail fixation demonstrated significantly less axial range of motion and greater torsional stiffness than antegrade fixation in both transverse and comminuted fracture patterns. However, there appeared to be a biomechanical trend of greater resistance to shortening for antegrade nails.     

逆行交锁髓内钉治疗股骨远端骨折

目的 探讨逆行交锁髓内钉在治疗股骨远端骨折中的应用价值。方法 采用逆行交锁髓内钉对22例AO分型为A、C型新鲜股骨远端骨折病例行内固定。结果 所有病例均获随访，21例获牢固骨性愈合，未见畸形愈合、感染。1例发生主钉尾端处骨折，1例发生近端锁钉断裂。术后根据KSS评分体系，评价优14例，良6例，一般2例，优良率90．9％。结论 逆行交锁髓内钉适用于股骨远端骨折，具有高度的稳定性，操作简单，出血少，并发症少，功能恢复快。     

A mechanical study of gap motion in cadaveric femurs using short and long supracondylar nails

OBJECTIVE: To determine the relative stability achieved in unstable supracondylar femur fractures treated with long (36 cm) and short (20 cm) retrograde intramedullary nails using 1 or 2 proximal locking bolts. We hypothesized that longer nails would reduce fracture site motion compared with short nails and that 2 proximal locking bolts would improve stability compared with 1 proximal locking bolt. DESIGN: Nine pairs of matched human cadaveric femurs were instrumented with 20-cm and 36-cm retrograde intramedullary nails (all 12-mm diameter, Biomet, Warsaw, IN) following reaming to 13 mm. Transverse supracondylar gap (6 mm) osteotomies were created. The femurs were mounted and cyclically tested separately in coronal plane bending and sagittal plane bending on a materials testing system. Fracture site translation was measured using a digital caliper in the respective plane. SETTING: Orthopaedic biomaterials laboratory. RESULTS: With 2 proximal locking bolts, average sagittal translation was 7.2 mm and 1.8 mm, respectively, for the 20-cm and 36-cm nails. Coronal translation was 6.3 mm and 4.3 mm, respectively. With a single proximal locking bolt, average sagittal translation was 7.6 mm and 2.2 mm, respectively, for the 20-cm and 36-cm nails. Coronal translation was 13.6 mm and 4.4 mm, respectively. A statistically significant difference in fracture site translation was found in each pairing by Student t test (P < 0.005), except coronal translation with 2 proximal locking bolts (P = 0.056). Free-body analysis predicts higher local stresses at the proximal interlocks of the shorter nail. CONCLUSIONS: Longer nails provide improved initial fracture stability when compared with short retrograde nails for supracondylar femur fractures due to a more stable mechanical interaction between the femoral diaphysis and the nail. A second proximal locking bolt in the long nail provides no additional stability.     

A biomechanical study on flexible intramedullary nails used to treat pediatric femoral fractures

Flexible intramedullary nails have been indicated to treat femoral fractures in pediatric patients. The purpose of this study was to examine the stability of simulated transverse fractures after retrograde intramedullary flexible nail fixation. Various nail diameter combinations were tested using composite femurs in bending, torsion, and a combined axial/bending test where a vertical compressive force was applied to the femoral head. The cross-sectional percent area fill of the nails within the femurs was also determined. In 4 point bending, the greatest repair stiffness was 12% of the intact stiffness. In torsion, the greatest stiffness was 1% of the intact stiffness for either internal or external rotation. The greatest repair stiffness was 80% of the intact stiffness for a compressive load applied to the femoral head. Nail combinations with single nail diameters greater than 40% of the mid-shaft canal width, as measured from an AP radiograph, prevented the fracture from being reduced and left a posterior gap. Flexible intramedullary nails may be of value in the treatment of pediatric femoral fractures, but care must be taken to insert nails that are correctly sized for the canal and to protect the healing fracture from high torsional and bending loads.     

Bending and torsional stiffness in cadaver humeri fixed with a self-locking expandable or interlocking nail system: a mechanical study

OBJECTIVES: This study was designed to gain data about a new expandable, noninterlocked intramedullary nail's capacity to stabilize unstable transverse humeral shaft fractures without the need for interlocking, thus making nail implantation simpler and to prove our goal hypothesis: that in a midshaft osteotomy of the humeral shaft the expandable humeral nail will show the same bending and torsional stiffness as an interlocked humeral nail, when implanted correctly according to the manufacturer's instructions. DESIGN: Pair randomization. SETTING: Mechanical laboratory testing. PARTICIPANTS: Eight pairs of freshly harvested cadaveric humeri. INTERVENTIONS: Fracture model was a midshaft transverse osteotomy, gapped to 3 mm. Each humerus pair received an expandable humeral nail (Fixion) or an interlocked humerus nail (Synthes) through a retrograde approach. The humeri were fixed in polymethylmethacrylate cylinders and tested in a servo-pneumatic material-testing machine. MAIN OUTCOME MEASUREMENTS: Torsional stiffness and bending stiffness of the nail-bone-construction. RESULTS: Expandable nails (interlocked nails) showed a lateral bending stiffness of 0.73 +/- 0.14 (0.63 +/- 0.1) KN/mm (P = 0.026) and a frontal bending stiffness of 0.67 +/- 0.18 (0.58 +/- 0.09) KN/mm (P = 0.084). Torsional stiffness values were 0.13 +/- 0.19 (0.43 +/- 0.09 Nm/degrees) (P = 0.012). Lower torsional stiffness in the expandable nail group was observed in humeri with a funnel shaped proximal intramedullary canal. CONCLUSIONS: The nail systems showed similar characteristics for frontal bending (P = 0.084), but not for lateral bending (P = 0.026). For lateral bending, the Fixion nail showed significantly more stiffness than the UHN nail (P = 0.026). There was significantly lower torsional stiffness with expandable nails compared with interlocked nails. Clinical correlation would suggest that in rotationally unstable fractures (A2 and A3 diaphyseal fractures), interlocked nails would provide increased stability over expandable nails.     

Nailing versus plating for comminuted fractures of the distal femur: a comparative biomechanical in vitro study of three implants

Purpose

The purpose of our study was to determine the biomechanical properties of three different implants utilized for internal fixation of a supracondylar femur fracture. The retrograde supracondylar nail (SCN), the less invasive stabilization system plate (LISS) and the distal femoral nail (DFN) were tested and their biomechanical properties compared.

Methods

Twenty pairs of fresh-frozen human femura were used. Each femur was osteotomised to simulate a comminuted supracondylar fracture (AO/OTA 33.A3) and then randomized to fracture fixation with either SCN (n=9) or LISS (n=9). Each contralateral femur was stabilized with DFN as a control (n=18). Two femur pairs were spent on pretesting. All femura were subjected to axial (10–500 N) and torsional (0.1–14 Nm) loading.

Results

Eighteen matched femur pairs were analyzed. The post-loading median residual values were 49.78, 41.25 and 33.51% of the axial stiffness of the intact femur and 59.04, 62.37 and 46.72% of the torsional stiffness of the intact femur in the SCN, LISS and DFN groups. There were no significant differences between the three implants concerning axial and torsional stiffness.

Conclusions

All implants had sufficient biomechanical stability under physiological torsional and axial loading. All three implants have different mechanisms for distal locking. The SCN nail with the four-screw distal interlocking had the best combined axial and torsional stiffness whereas the LISS plate had the highest torsional stiffness.     

Biomechanical evaluation of retrograde docking nailing to a total hip arthroplasty stem in a periprosthetic femur fracture model

IntroductionSlotted nails allow a connection to a total hip arthroplasty (THA) stem and act as intramedullary load carrier. This study compares construct stiffness, cycles to failure and failure load between a retrograde slotted femur nail construct docked to a THA stem and a lateral locking plate in a human periprosthetic femur fracture model.Materials and methodsIn seven pairs of fresh-frozen human anatomic femora with cemented THA, a transverse osteotomy was set simulating a Vancouver type B1 fracture. The femora were instrumented pairwise with either a retrograde slotted nail coupled to the prosthesis stem, or a locking plate plus a locking attachment plate. Four-point mediolateral bending, torsional and axial bending construct stiffness was investigated via non-destructive tests. Cyclic testing under progressively increasing physiologic loading was performed at 2 Hz until catastrophic construct failure.ResultsMediolateral bending stiffness did not differ significantly between the two groups (P=0.17) but exhibited a biphasic profile with significantly increased stiffness in both groups (P<0.01). Nail constructs provided a significantly lower torsional stiffness (0.49 ± 0.66 Nm/°) than plate constructs (1.70 ± 0.86 Nm/°), P=0.03. Axial bending stiffness did not differ significantly between the groups (Nail: 605 ± 511 N/mm; Plate: 381 ± 428 N/mm), P=0.61. Cycles to failure and failure load were significantly higher for the plate constructs (25’700 ± 8’341; 3’070 ± 1334 N) compared with the nail constructs (20’729 ± 7’949; 2’573 ± 1295 N), P=0.04.ConclusionThe docking nail construct provides an intramedullary fixation with connection to the prosthesis stem; however, it is biomechanically weaker in stable fractures compared to the plate construct.     

Biomechanical comparison of bending and torsional properties in retrograde intramedullary nailing of humeral shaft fractures.

OBJECTIVE: To establish whether the bending and torsional stiffness of an implanted nail are influenced by nail design and nail-bolt interface, this study compared two implanted retrograde nail systems: the AO/ASIF unreamed humeral nail (UHN) and the Russell-Taylor (RT) nail. DESIGN: Pair randomization. SETTING: Mechanical laboratory testing. SPECIMENS: Twelve pairs of freshly harvested cadaveric humeri. METHODS: Transverse fractures were simulated with a standardized midshaft osteotomy and a three-millimeter gap. Both nails were proximally and distally interlocked. The RT nail has a single interlock at its base and tip. The UHN has double interlocking both proximally and distally. The screw hole design of the RT nail features slots, whereas the UHN has round screw holes. MAIN OUTCOME MEASURES: Anteroposterior and mediolateral bending stiffness and torsional stiffness. RESULTS: The RT nail showed higher bending stiffness in anteroposterior and mediolateral bending. Large differences were seen in the torsional characteristics: for the first 30 degrees, the RT nail showed a much lower resistance against torsion than the UHN. Analysis of variance of stiffness at four, six, and eight newton-meters showed statistical significance (p < 0.0001). Torsional stiffness, defined as the slope of a straight line approximated to between 75 and 100 percent of the maximum torque, was very similar in both nails. CONCLUSION: The torsional differences between the two nail systems are attributable to the nail-bolt interface of the RT nail. This dynamic system allows a clinically relevant degree of movement. The greater resistance to rotatory forces of the UHN is explained by the fact that the interlocking at its tip and base creates a static rather than a dynamic system.     

多孔髓内针生物力学特性的有限元分析

背景：髓内针为长骨转移癌预防性内固定的常用选择之一,但存在锁钉周围应力集中,锁钉弯曲或折断等问题。选择更为坚强、持久的预防性内固定可有效改善骨转移癌患者的生存质量。目的：研究适用于长骨转移癌的多孔髓内针的生物力学特性,为选取打孔方案及生物力学试验提供理论依据。方法：采用有限元分析的方法,测量4种长骨髓内针打孔方案下截面刚度及整体刚度的变化,孔直径有2mm与3mm两种,导程有11mm与22mm两种。结果：孔直径2mm对截面拉压刚度及扭转刚度降低8.45%和8.13%,对平行于打孔平面方向的弯曲刚度几乎无影响,但在垂直于打孔平面方向的弯曲刚度降低15.96%。髓内针采取孔直径2mm、导程11mm、每导程4个孔、孔均匀布置的打孔方案,载荷下应力增长率及整体刚度改变最小。结论：髓内针侧壁打孔可造成髓内针刚度降低,孔周围出现应力集中的现象,影响髓内针的抗疲劳性。综合静态压缩、弯曲的分析结果,孔直径2mm,导程11mm,每导程4个孔,孔均匀布置的打孔方案的效果最佳。     

Tibiotalocalcaneal arthrodesis: a biomechanical comparision of multiplanar external fixation with intramedullary fixation

BACKGROUND: Methods of achieving tibiotalocalcaneal arthrodesis include intramedullary nailing, crossed lag screws, blade plates, and external fixation. While reports in the orthopaedic literature have compared the biomechanical properties of some of these fixation techniques, to our knowledge none has evaluated multiplanar external fixation. The purpose of this study was to compare the biomechanical properties of intramedullary nail fixation and external ring fixation for tibiotalocalcaneal arthrodesis. MATERIALS AND METHODS: Tibiotalocalcaneal arthrodesis was performed on ten matched pairs of fresh-frozen human cadaveric legs. A ring fixator stabilized the arthrodesis in one leg from each pair and a 10 mm x 150 mm nail inserted retrograde across the subtalar and ankle joint stabilized the arthrodesis in the contralateral leg. The bending stiffness of the resulting constructs was quantified in plantarflexion, dorsiflexion, inversion, and eversion, and torsional stiffness was measured in internal and external rotation. RESULTS: No difference in bending stiffness between the two constructs was identifiable in any of the four bending directions (p > 0.05). Torsional stiffness was approximately two-fold greater in both internal and external rotation in specimens with the ring fixator arthrodesis than in those with the intramedullary nail (p = 0.002). CONCLUSION: The ring fixator provides a stiffer construct than a 10 mm x 150 mm intramedullary nail in torsion, but no difference in bending stiffness was demonstrable. Both techniques can provide satisfactory fixation; however, the ring fixator may better minimize rotational joint motion. CLINICAL RELEVANCE: This study provides a basis for selecting an arthrodesis method that offers optimized fixation.     

股骨髁上骨折的手术治疗

目的探讨提高股骨髁上骨折的手术治疗效果。方法(1)取6具人尸体新鲜股骨标本,制成有1cm骨缺损的股骨髁上骨折。采用逆行带锁髓内针和股骨髁支撑钢板两种内固定器材分别固定各骨折。对固定后的骨折进行应力测定,比较两种内固定物固定骨折的生物力学特性。用SPSS统计软件对结果进行分析。(2)对1995年8月到2000年12月收治的并可随访到的36例37肢体股骨髁上骨折(主要对其中的股骨髁支撑钢板16例16肢体,逆行带锁髓内针14例15肢体)进行临床随访分析,比较逆行带锁髓内针与股骨髁支撑钢板手术治疗股骨髁上骨折的临床结果。结果(1)生物力学性能用股骨髁支撑钢板固定的骨折的抗压缩强度值低于用逆行带锁髓内针固定。用股骨髁支撑钢板固定的骨折的抗弯曲的强度值高于用逆行带锁髓内针固定。( 2 )临床结果根据Neer膝关节功能评分标准,本组病例共有优秀26肢体,良好8肢体,可以1肢体,差2肢体。总体优良率91 9%。钢板类优良率94 7%,髓内针93 3%。膝关节屈伸活动范围平均110°。结论手术治疗股骨髁上骨折可获得良好的结果。逆行带锁髓内针和股骨髁支撑钢板固定在生物力学性能及临床应用方面各有优势。     

Antegrade versus retrograde titanium elastic nail fixation of pediatric distal-third femoral-shaft fractures: a mechanical study

OBJECTIVES: To determine whether the stability of elastic stable intramedullary nail (ESIN) constructs differ in terms of antegrade versus retrograde insertion for the fixation of pediatric distal-third transverse femoral-shaft fractures. METHODS: Ten synthetic composite adolescent-sized femur models and 20 flexible titanium (Ti) intramedullary (IM) nails were divided into antegrade and retrograde groups. A simulated transverse fracture was created in each of 10 models in the distal-third region of the shaft (more precisely near the distal fifth). The fractures were then stabilized with ESIN. The specimens were subjected to four-point bending and then axial torsion. Flexural forces were applied to the medial aspect of the model across the fracture site at a rate of 0.05 mm/s to a maximum displacement of 3.7 mm (7 degrees). Torsional moments were applied to the distal aspect of the model in internal and external rotation at a rate of 0.75 degrees/s to a maximum of 10 degrees. Loads and stiffnesses were determined between consistent displacement limits; differences were compared using t tests (alpha = 0.05, two tailed). RESULTS: Flexural stiffness was significantly greater in the retrograde group (350 +/- 72 N/mm) compared with antegrade (195 +/- 95 N/mm; P = 0.02). A 66-kg load placed across the fracture displaced the site 3.7 mm for the antegrade group, whereas the retrograde group required a load 89% greater (125 kg). Although torsional stiffness tended to be greater in the antegrade group, the differences were not statistically significant (P = 0.2). CONCLUSIONS: Although the recommendation for distal-third femur fractures is antegrade nail insertion, this study demonstrates that given satisfactory cortical starting points in the distal fragment, retrograde insertion provides greater stability. These mechanical testing data are the first to address this specific fracture scenario and may aid surgical decision making.     

股骨髁上交锁髓内钉治疗股骨髁上骨折

目的总结股骨髁上交锁髓内钉治疗股骨髁上骨折的疗效.方法对13例股骨髁上交锁髓内钉治疗股骨髁上骨折进行回顾性分析.结果13例均在4～8个月愈合,无交锁钉松动、折弯、断裂情况,患肢膝关节功能恢复满意.结论股骨髁上交锁髓内钉治疗股骨髁上骨折具有骨折复位好、固定坚强、可早期活动关节及骨折愈合率高等优点,是一种较为理想的方法.     

Biomechanics of femoral interlocking nails

Today there is a variety of different interlocking intramedullary nail designs available for the femur. We compared different nail types in the bone implant complex (BIC) of four unreamed solid nails and a slotted reamed nail with simulated comminuted mid shaft fractures to see if there are major differences in stiffness for axial load, bending and torsion. The fractures were simulated by a 2 cm defect osteotomy in paired human cadaver femora. Each bone was tested intact in a universal testing machine, osteotomy and osteosynthesis were performed, and the BIC was tested. Relative stiffness was calculated. In torque testing the unslotted solid nail showed significantly more stiffness (0.6-1.8 Nm/degrees) compared to the slotted nail (0.2 Nm/degrees). Compared to intact bone (6.9 Nm/degrees), both groups of nails were significantly less stiff (relative stiffness 2-20%). In axial load and bending testing the large diameter unreamed nail showed significantly higher stiffness (32-68%). This study shows that stiffness of bone implant complex in interlocking femoral nails is more dependent on nail profile than on the pressfit of nails in the medullary canal.     

Biomechanik von Femurverriegelungsmarknägeln im Knochen-Implantat-Verbund

Today there is a variety of different interlocking intramedullary nail designs available for the femureach designed with a different approach to achieve stability for fracture fixation. We compared different nail types in the bone-implant complex (BIC) of four unreamed solid nails and a slotted, reamed nail to see if there are major differences in stiffness for axial load, bending and torsion. We simulated comminuted mid-shaft fractures by a 2 cm defect osteotomy in paired human cadaver femora. Each bone was tested intact in a Universal testing machine. The results were recorded, osteotomy and osteosynthesis were performed, and the BIC was tested. Relative stiffness was calculated for each individual bone. ForP-values less than 0.01 (‘least significance difference test’) the difference between groups was considered to be significant. In torque testing the unslotted solid nails showed significantly more stiffness (0.6–1.8 Nm/^o) compared to the slotted nail (0.2 Nm/^p). Compared to intact bone (6.9 Nm/^o), both groups of nails were significantly less stiff (relative stiffness 2–20%). In axial load and bending testing, the largediameter unreamed nail showed greater higher stiffness (32–68%). This study shows that stiffness of the BIC in interlocking femoral nails is more dependent on nail profile than on the press-fit of nails in the medullary canal. For torque stiffness the absence of a slot is of special importance. According to our study, all of the unslotted nails tested give adequate stability for fracture fixation.     

Femoral fracture at the proximal end of an intramedullary supracondylar nail: a case report

Retrograde intramedullary supracondylar nails have been added to the orthopedic armamentarium for treatment of distal femoral fractures. Major complications of this new technique have not been noted. We report a case of a femoral fracture at the proximal end of a retrograde intramedullary supracondylar nail. We hypothesize that this complication may be due to the proximal end of the nail acting as a stress riser, with the cortical holes drilled for the interlocking screws compounding this effect.     

Biomechanical comparison of flexible stainless steel and titanium nails with external fixation using a femur fracture model

There are several options available for surgical stabilization of pediatric femoral shaft fractures. The purpose of this study was to compare the stability afforded by Ender stainless steel nails, titanium elastic nails, and one-plane unilateral external fixators for the fixation using a synthetic adolescent midshaft femur fracture model. The anterior-posterior (sagittal plane) bending, lateral (coronal plane) bending, torsional, and axial stiffness values were calculated using 6 different fixation configurations. These included pairs of 3.5-mm-diameter Ender nails with and without distal locking, 3.5- and 4.0-mm-diameter titanium elastic nails as well as single- and double-stacked monolateral external fixators. Eight synthetic femur models, 4 each with simulated transverse and comminuted fracture patterns, were sequentially tested for stability afforded by the various fracture fixation configurations. External fixation exhibited significantly greater control of anterior-posterior angulation compared with all flexible-nailing systems. Although Ender nails were slightly superior to titanium nails in control of sagittal plane angulation, this was not statistically significant. Compared with the external fixation constructs, all 4 flexible nail constructs demonstrated higher torsional stability. For prevention of axial shortening, all fixation methods were similar for the transverse fracture pattern, whereas external fixation was superior to flexible nails in the comminuted fracture model. No significant benefit was demonstrated with double stacking of external fixators. These findings may help guide clinicians choose the optimal fixation method for treatment of pediatric femoral shaft fractures.     

Construct stiffness of different fixation methods for supracondylar femoral fractures above total knee prostheses

Supracondylar fracture of the femur after total knee arthroplasty has an estimated frequency of 0.6%-2.5% among total knee recipients and presents an extremely difficult problem when encountered. The goal of this study is to determine the most stable method of fixation of these supracondylar fractures among currently available devices. Synthetic composite femurs with properties similar to human bone were used, and identical, unstable supracondylar fractures were created in each. Osteotomized specimens were placed into four groups of five. Each group was then tested with one of four devices: the Green-Seligson-Henry (GSH) intramedullary nail, AO 95 degrees blade plate, dynamic condylar screw and sideplate, and condylar buttress plate. After stabilization with the different types of fixation, the constructs were tested individually for bending stiffness in four modes: flexion, extension, varus, and valgus bending. The stiffest fixation was determined in each of the four bending planes. Resistance to all tested directions was greatest for the condylar screw and sideplate construct. Resistance to flexion (stiffness = 30.96 N/mm), extension (stiffness = 36.36 N/mm), varus (stiffness = 35.46 N/mm), and valgus forces (stiffness = 32.26 N/mm) was highest in the group fixed with the dynamic condylar screw. This may be due to the purchase gained by the large lag screw into the distal femur, or it may be the result of the total rigidity of the implant. Although the femoral samples used in this study do not duplicate the typical osteopenic bone encountered at the site of a total knee arthroplasty, they do allow direct comparison of the fixation devices by removing the variability associated with cadaveric bone samples.     

带锁髓内钉治疗股骨骨不连

目的：分析股骨骨不连原因,观察带锁髓内钉治疗股骨骨不连的临床效果。方法：2001年1月至2009年1月,采用带锁髓内钉治疗31例股骨骨不连,男19例,女12例;年龄18～73岁,平均32.5岁。其中骨不连发生在股骨干24例,股骨远端7例。股骨干骨不连采用标准带锁髓内钉治疗,股骨远端骨不连采用股骨髁上带锁髓内钉治疗。一般行切开带锁髓内钉固定及自体骨移植,所有病例均使用扩髓技术。结果：31例全部获得随访,时间14～72个月,平均23个月。30例获骨性愈合,愈合时间3～6个月,平均4.6个月;另1例髓内钉固定后再次给予植骨后愈合。髋关节功能全部正常,术后1年膝关节行HSS评分平均为（89.97±5.21）分。结论：采用带锁髓内钉治疗股骨骨不连具有固定可靠,稳定性好的优点,有利于肢体、关节早期功能锻炼。扩髓结合自体骨移植可获良好临床效果。