Background: Newer generation intramedullary (IM) tibial nails provide several distal interlocking screw options. The objectives were to determine: 1) if the new oblique interlocking option provides superior stability,...Background: Newer generation intramedullary (IM) tibial nails provide several distal interlocking screw options. The objectives were to determine: 1) if the new oblique interlocking option provides superior stability, 2) which screw orientation/ configuration is the most biomechanically stable, and 3) if three distal interlocking screws provide better stability. Methods: A preliminary experiment was performed in torsion, compression, and bending tests with four different screw configurations: (I) one medial-to-lateral and one oblique, (II) two me-dial-to-lateral, (III) one medial-to-lateral and one anterior-to-posterior, and (IV) one medial-to-lateral, one anterior-to-posterior and one oblique in simu-lated distal metaphyseal fracture tibiae. Twenty- four Synthes EXPERT tibial IM nails were used for six specimens of each screw configuration. Parts I and II, tibial IM nails were locked with 5.0 mm in-terlocking screws into simulated distal tibiae (PVC and composite analogue tibia). Part III, the two most stable configurations were tested using five pairs of simulated cadaveric distal tibiae metaphy-seal fractures. Results: Significant differences were attributable to distal screw orientation for intrame- dullary nailing of distal tibia fractures. Configura-tions II and IV were found to be more stable than the other two configurations. No significant differ-ence was detected in construct stability in all modes of testing between Configurations II and IV. Dis-cussion: Configuration I did not provide superior stability for the distal tibia fracture fixation. Con-figurations II and IV provided equivalent stability. When choosing IM fixation for treatment of distal tibia metaphyseal fractures two medial-to-lateral screws provide the necessary stability for satisfac-tory fixation. Clinical Relevance: This study indi-cated an option for operative treatment of distal metaphyseal tibia fracture fixation where preserva-tion of soft tissue and rigid stabilization are needed.展开更多
In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation...In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation stability comparable to those of anterograde intramedullary nailing and locking plate which achieve clinically favorable outcomes. In retrograde intramedullary nailing, a nail entry point is made in the diaphysis, for which reduction of stiffness of the humerus is of concern. Thus, we investigated the influence of a nail entry point made in the diaphysis on humeral strength. Retrograde intramedullary nailing had fixation stability against bending and a force loaded in the rotation direction comparable to those of anterograde intramedullary nail and locking plate. Displacement by the main external force loaded on the humerus, compressive load, was less than half in the bone fixed by retrograde intramedullary nailing compared with that in the bone fixed with a locking plate, showing favorable fixation stability. It was clarified that stiffness of the humerus against rotation and a load in the compression direction is not reduced by a nail entry point made by retrograde intramedullary nailing.展开更多
Background: There are at least 5 very popular methods described for the correction of mild to moderate hallux valgus deformities. Despite of reported and self experienced good results in favorable fitting preoperative...Background: There are at least 5 very popular methods described for the correction of mild to moderate hallux valgus deformities. Despite of reported and self experienced good results in favorable fitting preoperative anatomical conditions of some of these methods;it seems that no one is really satisfying under “difficult” or non favorable preoperative anatomic conditions. How could an optimum operation method for a satisfying correction of a mild to moderate hallux valgus look like? The well known criteria for an optimally satisfying method to achieve full normalization of important forefoot parameters under all conditions should be a lateralization, plantarization and derotation of the Ist metatarsal head and also a normalization of the distal metatarsal articular angle (DMAA) in combination with a soft tissue correction. Methods: In order to achieve this outcome without the disadvantages of shortening or the need for unloading, we developed a new operation technique and new fixation devices. We performed a simple transverse lazy-L subcapital osteotomy and after an additional soft tissue release the Ist metatarsal head was restored to its preplaned optimum position in terms of narrowing the IM angle, plantarization, correction of the hallux valgus angle, derotation of a pronation l malrotation and improvement of the DMAA. Fixation was achieved with an intramedullary angel-stable transfixed 30 mm titanium plate. The rigidity of the implant rendered interfragmental compression or solid bone contact unnecessary. The goal was only an optimal correction. All patients were allowed to ambulate with full weightbearing immediately after the operation. Results: We retrospectively reviewed 346 patients (433 feet) who underwent subcapital osteotomy between May 2007 and December 2011;308 were women and 38 men;their mean age was 65 years. The follow-up investigation was performed on average after 6.5 years (78 months);range 5.5 to 10 years (66 to 120 months). The AOFAS Score improved from 61.18 to 96.82 (t = 55.13, p ° to 4.21° (t = 89.70, p ° to 7.75° (t = 51.68, p ° to 6.61° (t = 29.34, p < 0.001). Minimal shortening of the first metatarsal (0.33 mm) and no recurrence of the deformity was observed. Conclusion: A new access to hallux valgus surgery is presented. Our results show that interfragmental compression between the osteotomy partners or good interfragmental contact is not necessary when a rigid intramedullary fixation device is used. The goal of this approach to hallux valgus surgery was to achieve excellent correction and a very rigid intramedullary angle-stable locked implant. The procedure yielded excellent results and was associated with no recurrence of hallux valgus.展开更多
Post cam mechanism of Posterior Stabilized (PS) knee prostheses is useful to realize intrinsic stability for cases with severe degeneration. However, some retrieval studies report severe failure of the polyethylene ti...Post cam mechanism of Posterior Stabilized (PS) knee prostheses is useful to realize intrinsic stability for cases with severe degeneration. However, some retrieval studies report severe failure of the polyethylene tibial post. We thought that severe failures were caused by high loads during daily activities. In the current study, we performed a compression test and a finite element analysis of the mechanical forces produced in the tibial post in posterior-stabilized knee prostheses in order to develop a specification for the tibial posts found in the polyethylene inserts of PS knee prostheses. Anterior tibial post impingement and posterior tibial post impingement were simulated. The surface pressure values detected in the compression test were consistent with those obtained in the FE analysis. Of the three designs, the lowest von Mises stress values were generated inside the round tibial post;therefore, tibial posts should be round. The risk of tibial post failure was low when 500 or 1000 N was loaded onto the knee joint. It was suggested that tibial post failure occurs when the shear strain at the base of the tibial post exceeds 0.1.展开更多
Purpose:Intramedullary implants are well accepted fixation of all types of intertrochanteric(IT)frac-tures,both stable and unstable types.Intramedullary nails have an ability to effectively support the posteromedial p...Purpose:Intramedullary implants are well accepted fixation of all types of intertrochanteric(IT)frac-tures,both stable and unstable types.Intramedullary nails have an ability to effectively support the posteromedial part,but fail to buttress the broken lateral wall requiring lateral augmentation.The aim of this study was to evaluate the outcome of proximal femoral nail augmented with trochanteric buttress plate for broken lateral wall with IT fractures,which was fixed to the femur through hip screw and anti-rotation screw nail.Methods:Of 30 patients,20 had Jensen-Evan typeⅢand 10 had type V fractures.Patients with IT fracture of broken lateral wall and aged more than 18 years,in whom satisfactory reduction was achieved by closed methods,were included in the study.Patients with pathologic or open fractures,polytrauma,prior hip surgery,non-ambulatory prior to surgery,and those who refused to participate were excluded.The operative time,blood loss,radiation exposure,quality of reduction,functional outcome,and union time were evaluated.All data were coded and recorded in Microsoft Excel spread sheet program.SPSS 20.0 was used for data analysis and normality of the continuous data was checked using Kolmogorv Smirnov test.Results:The mean age of patients in the study was 60.3 years.The mean duration of surgery(min),mean intra-operative blood loss(mL)and mean number of exposures were 91.86±12.8(range 70-122),144.8±3.6(range 116-208),and 56.6(range 38-112),respectively.The mean union time was 11.6 weeks and the mean Harris hip score was 94.1.Conclusion:Lateral trochanteric wall in IT fractures is significantly important,and needs to be recon-structed adequately.Nail-plate construct of trochanteric buttress plate fixed with hip screw and anti-rotation screw of proximal femoral nail can be successfully used to augment,fix or buttress the lateral trochanteric wall giving excellent to good results of early union and reduction.展开更多
目的比较股骨远端90°锁定钢板与弹性髓内钉治疗学龄期儿童股骨下段不稳定型骨折的疗效。方法采用随机数字表法将75例学龄期股骨下段不稳定型骨折患儿分成观察组(采用股骨远端90°锁定钢板治疗,38例)与对照组(采用闭合或切开复...目的比较股骨远端90°锁定钢板与弹性髓内钉治疗学龄期儿童股骨下段不稳定型骨折的疗效。方法采用随机数字表法将75例学龄期股骨下段不稳定型骨折患儿分成观察组(采用股骨远端90°锁定钢板治疗,38例)与对照组(采用闭合或切开复位弹性髓内钉治疗,37例)。记录手术情况、骨折复位及愈合情况、术后再移位发生率。采用HSS评分评价膝关节功能。结果患儿均获得随访,时间6~24个月。术中出血量、术中透视次数观察组均少于对照组(P<0.05)。术后3 d X线片显示两组骨折均复位良好。两组骨折愈合时间2.5~5个月。末次随访时,HSS评分优良率观察组高于对照组(P<0.05)。术后再移位发生率观察组低于对照组(P<0.05)。结论与弹性髓内钉相比,股骨远端90°锁定钢板治疗学龄期儿童股骨下段不稳定型骨折,术中出血量、透视次数更少,术后骨折再移位率更低,疗效更好。展开更多
文摘Background: Newer generation intramedullary (IM) tibial nails provide several distal interlocking screw options. The objectives were to determine: 1) if the new oblique interlocking option provides superior stability, 2) which screw orientation/ configuration is the most biomechanically stable, and 3) if three distal interlocking screws provide better stability. Methods: A preliminary experiment was performed in torsion, compression, and bending tests with four different screw configurations: (I) one medial-to-lateral and one oblique, (II) two me-dial-to-lateral, (III) one medial-to-lateral and one anterior-to-posterior, and (IV) one medial-to-lateral, one anterior-to-posterior and one oblique in simu-lated distal metaphyseal fracture tibiae. Twenty- four Synthes EXPERT tibial IM nails were used for six specimens of each screw configuration. Parts I and II, tibial IM nails were locked with 5.0 mm in-terlocking screws into simulated distal tibiae (PVC and composite analogue tibia). Part III, the two most stable configurations were tested using five pairs of simulated cadaveric distal tibiae metaphy-seal fractures. Results: Significant differences were attributable to distal screw orientation for intrame- dullary nailing of distal tibia fractures. Configura-tions II and IV were found to be more stable than the other two configurations. No significant differ-ence was detected in construct stability in all modes of testing between Configurations II and IV. Dis-cussion: Configuration I did not provide superior stability for the distal tibia fracture fixation. Con-figurations II and IV provided equivalent stability. When choosing IM fixation for treatment of distal tibia metaphyseal fractures two medial-to-lateral screws provide the necessary stability for satisfac-tory fixation. Clinical Relevance: This study indi-cated an option for operative treatment of distal metaphyseal tibia fracture fixation where preserva-tion of soft tissue and rigid stabilization are needed.
文摘In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation stability comparable to those of anterograde intramedullary nailing and locking plate which achieve clinically favorable outcomes. In retrograde intramedullary nailing, a nail entry point is made in the diaphysis, for which reduction of stiffness of the humerus is of concern. Thus, we investigated the influence of a nail entry point made in the diaphysis on humeral strength. Retrograde intramedullary nailing had fixation stability against bending and a force loaded in the rotation direction comparable to those of anterograde intramedullary nail and locking plate. Displacement by the main external force loaded on the humerus, compressive load, was less than half in the bone fixed by retrograde intramedullary nailing compared with that in the bone fixed with a locking plate, showing favorable fixation stability. It was clarified that stiffness of the humerus against rotation and a load in the compression direction is not reduced by a nail entry point made by retrograde intramedullary nailing.
文摘Background: There are at least 5 very popular methods described for the correction of mild to moderate hallux valgus deformities. Despite of reported and self experienced good results in favorable fitting preoperative anatomical conditions of some of these methods;it seems that no one is really satisfying under “difficult” or non favorable preoperative anatomic conditions. How could an optimum operation method for a satisfying correction of a mild to moderate hallux valgus look like? The well known criteria for an optimally satisfying method to achieve full normalization of important forefoot parameters under all conditions should be a lateralization, plantarization and derotation of the Ist metatarsal head and also a normalization of the distal metatarsal articular angle (DMAA) in combination with a soft tissue correction. Methods: In order to achieve this outcome without the disadvantages of shortening or the need for unloading, we developed a new operation technique and new fixation devices. We performed a simple transverse lazy-L subcapital osteotomy and after an additional soft tissue release the Ist metatarsal head was restored to its preplaned optimum position in terms of narrowing the IM angle, plantarization, correction of the hallux valgus angle, derotation of a pronation l malrotation and improvement of the DMAA. Fixation was achieved with an intramedullary angel-stable transfixed 30 mm titanium plate. The rigidity of the implant rendered interfragmental compression or solid bone contact unnecessary. The goal was only an optimal correction. All patients were allowed to ambulate with full weightbearing immediately after the operation. Results: We retrospectively reviewed 346 patients (433 feet) who underwent subcapital osteotomy between May 2007 and December 2011;308 were women and 38 men;their mean age was 65 years. The follow-up investigation was performed on average after 6.5 years (78 months);range 5.5 to 10 years (66 to 120 months). The AOFAS Score improved from 61.18 to 96.82 (t = 55.13, p ° to 4.21° (t = 89.70, p ° to 7.75° (t = 51.68, p ° to 6.61° (t = 29.34, p < 0.001). Minimal shortening of the first metatarsal (0.33 mm) and no recurrence of the deformity was observed. Conclusion: A new access to hallux valgus surgery is presented. Our results show that interfragmental compression between the osteotomy partners or good interfragmental contact is not necessary when a rigid intramedullary fixation device is used. The goal of this approach to hallux valgus surgery was to achieve excellent correction and a very rigid intramedullary angle-stable locked implant. The procedure yielded excellent results and was associated with no recurrence of hallux valgus.
文摘Post cam mechanism of Posterior Stabilized (PS) knee prostheses is useful to realize intrinsic stability for cases with severe degeneration. However, some retrieval studies report severe failure of the polyethylene tibial post. We thought that severe failures were caused by high loads during daily activities. In the current study, we performed a compression test and a finite element analysis of the mechanical forces produced in the tibial post in posterior-stabilized knee prostheses in order to develop a specification for the tibial posts found in the polyethylene inserts of PS knee prostheses. Anterior tibial post impingement and posterior tibial post impingement were simulated. The surface pressure values detected in the compression test were consistent with those obtained in the FE analysis. Of the three designs, the lowest von Mises stress values were generated inside the round tibial post;therefore, tibial posts should be round. The risk of tibial post failure was low when 500 or 1000 N was loaded onto the knee joint. It was suggested that tibial post failure occurs when the shear strain at the base of the tibial post exceeds 0.1.
文摘Purpose:Intramedullary implants are well accepted fixation of all types of intertrochanteric(IT)frac-tures,both stable and unstable types.Intramedullary nails have an ability to effectively support the posteromedial part,but fail to buttress the broken lateral wall requiring lateral augmentation.The aim of this study was to evaluate the outcome of proximal femoral nail augmented with trochanteric buttress plate for broken lateral wall with IT fractures,which was fixed to the femur through hip screw and anti-rotation screw nail.Methods:Of 30 patients,20 had Jensen-Evan typeⅢand 10 had type V fractures.Patients with IT fracture of broken lateral wall and aged more than 18 years,in whom satisfactory reduction was achieved by closed methods,were included in the study.Patients with pathologic or open fractures,polytrauma,prior hip surgery,non-ambulatory prior to surgery,and those who refused to participate were excluded.The operative time,blood loss,radiation exposure,quality of reduction,functional outcome,and union time were evaluated.All data were coded and recorded in Microsoft Excel spread sheet program.SPSS 20.0 was used for data analysis and normality of the continuous data was checked using Kolmogorv Smirnov test.Results:The mean age of patients in the study was 60.3 years.The mean duration of surgery(min),mean intra-operative blood loss(mL)and mean number of exposures were 91.86±12.8(range 70-122),144.8±3.6(range 116-208),and 56.6(range 38-112),respectively.The mean union time was 11.6 weeks and the mean Harris hip score was 94.1.Conclusion:Lateral trochanteric wall in IT fractures is significantly important,and needs to be recon-structed adequately.Nail-plate construct of trochanteric buttress plate fixed with hip screw and anti-rotation screw of proximal femoral nail can be successfully used to augment,fix or buttress the lateral trochanteric wall giving excellent to good results of early union and reduction.
文摘目的比较股骨远端90°锁定钢板与弹性髓内钉治疗学龄期儿童股骨下段不稳定型骨折的疗效。方法采用随机数字表法将75例学龄期股骨下段不稳定型骨折患儿分成观察组(采用股骨远端90°锁定钢板治疗,38例)与对照组(采用闭合或切开复位弹性髓内钉治疗,37例)。记录手术情况、骨折复位及愈合情况、术后再移位发生率。采用HSS评分评价膝关节功能。结果患儿均获得随访,时间6~24个月。术中出血量、术中透视次数观察组均少于对照组(P<0.05)。术后3 d X线片显示两组骨折均复位良好。两组骨折愈合时间2.5~5个月。末次随访时,HSS评分优良率观察组高于对照组(P<0.05)。术后再移位发生率观察组低于对照组(P<0.05)。结论与弹性髓内钉相比,股骨远端90°锁定钢板治疗学龄期儿童股骨下段不稳定型骨折,术中出血量、透视次数更少,术后骨折再移位率更低,疗效更好。
