Rotational stability of Seidel nail distal locking mechanism

The intramedullary distal locking mechanism in the Seidel nail uses interference fit, avoiding the need of a screw traversing soft tissue and the risk of neurovascular injury. However, there is concern for its rotational stability. This study was designed to test the rotational stability of the distal locking mechanism under the least stable conditions. A transverse osteotomy was performed 10 cm proximal to the trochlea in 10 cadaveric humeri, followed by insertion of a 9 mm diameter Seidel nail and distally locked. The proximal humeral segments were removed. Rotational test to failure was performed with a material testing machine. The initial medullary diameter and the amount of flange spread measured 9.95 mm and 11.28 mm, respectively. Most of the flanges were found to be incompletely deployed. Failure occurred by slippage of the flanges. The average failure torque and torsional stiffness of the nail bone construct tested were 0.262 N m and 0.070 N m/ degrees . The Seidel nail distal locking mechanism has low rotational stability on mechanical testing. However, the low failure torque tested in vitro does not always preclude successful fracture healing and a good clinical outcome. Whether the presence of rotational micro motion would be beneficial to bone healing would need further investigation.     

A giant rheumatoid Geode of the humerus treated with a Marchetti-Vicenzi intramedullary nail

Giant rheumatoid Geodes are rare. When a fracture occurs through them, the poor quality of the bone remaining can present a dilemna for stabilisation and fixation. The retrograde Marchetti-Vicenzi intramedullary nail provides stable and dynamic fixation without compromising the poor quality surrounding bone and is a useful adjunct in treating these unique fractures.     

交锁髓内钉治疗肱骨病理骨折

目的评估采用交锁髓内钉及骨水泥强化方法治疗肱骨干及近端病理骨折的疗效。方法回顾2005年1月至2009年6月间采用顺行交锁髓内钉及骨水泥强化方法治疗的15例肱骨病理骨折的治疗情况,其中11例病理骨折,4例濒临骨折。结果 15例中,男11例,女4例,平均年龄51.1岁（29～65岁）。5例病变位于近端1/3,10例位于中1/3。平均手术时间121min（85～177min）,平均出血量650ml（400～1200ml）。4例接受输血（平均输血量RBC 2.3U）。12例术后随访超过12个月。其中10例结果优良。2例诉肩部僵硬。结论交锁髓内钉治疗肱骨病例性骨折,可提供稳定的固定并允许患肢早期活动。骨水泥强化是治疗节段性骨缺损的有效方法。     

Humeral fractures in the elderly: treatment with a reamed intramedullary locking nail

In the elderly person, comorbidities combined with lower functional demands tend to indicate non-operative treatment; however, fast functional recovery is mandatory to prevent loss of independency and social ability. This retrospective follow-up study included 40 people with a mean age of 75 (range 60-87) years. They had all received treatment with a reamed intramedullary nail for humeral fracture; 21 were operated after a mean of 6 (range 0-16) days, and 19 after a mean of 28 (range 9-63) days after a primary decision for non-operative treatment. In all, 5 cases (12.5%) were lost to follow-up. The primary healing rate was 94% (33/35) after a mean of 17 (range 6-61) weeks; 14% (5/35) needed re-operation, in 2 cases because of healing problems. Functional results could be assessed in 18 cases: the median Neer score was 90 (range 45-97) points and the median Morrey score 98 (range 74-100) points. The relative functional scores were 94 (range 89-101) and 100 (range 97-100) points, respectively. All functional scores were independent of introduction site and time to treatment. On the basis of these results we conclude that treatment of humeral fractures in the elderly with an intramedullary nail leads to good healing and functional results, and an acceptable re-operation rate.     

顺行肱骨交锁钉治疗肱骨干骨折

目的 探讨顺行肱骨交锁钉治疗肱骨干骨折的临床应用价值。方法 对2l例肱骨干骨折患行切开复位、顺行肱骨交锁钉内固定。结果术后随访3～20个月(平均14.6个月)，骨折愈合良好，仅l例出现桡神经一过性损伤。结论 顺行肱骨交锁钉交锁治疗肱骨干骨折疗效满意，还有减少桡神经损伤、感染等并发症、减少创伤，肘关节功能不受明显限制等优点。     

A new modular nail for the diaphyseal fractures of the humerus

Over a period of 5 years, 63 traumatic and eight pathological diaphyseal humeral fractures were treated with a new modular humeral nail. The nail is cannulated, square in shape - with concave sides - and has two different extensions that can be used with either the antegrade or the retrograde approach. Adequate rotational and axial stability is provided without the need for distal locking screws in the majority of fractures, while the need for proximal locking screws during the antegrade procedure is abolished. This study aims to present the ‘Garnavos’ nail and the results of its use, along with proposals and guidelines that should be considered whenever intramedullary nailing is selected for the treatment of diaphyseal humeral fractures.     

AO不扩髓胫骨髓内钉术中并发症及防治

目的探讨AO不扩髓胫骨髓内钉的术中并发症及防治.方法总结87例手术,平均年龄37.5岁.结果肢体缩短2例,术中再骨折5例,近端交锁不进2例,远端交锁不进4例,内外翻成角7例(均小于5度),皮肤及血管损伤3例,封闭螺钉安放失误2例.结论熟练掌握操作可以减少并发症,提高疗效.     

Advancing a guide wire for intramedullary nail across an obliterated medullary canal during femoral diaphyseal osteotomy: a technical trick

The use of a reamed intramedullary nail allows the immediate correction and stabilisation of deformity in diaphysis of the femur. Passing a guide wire after a femoral diaphyseal osteotomy can prove to be difficult, particularly if the medullary canal has been narrowed or obliterated by bone re-modelling after fracture repair. We present a technique to allow safe and accurate guide-wire passage.     

闭合复位逆行交锁髓内钉治疗股骨髁上A型骨折

目的总结临床应用闭合复位逆行交锁髓内钉治疗股骨髁上骨折的经验.方法1997年12月～2000年12月应用闭合复位逆行交锁髓内钉内固定的方法治疗新鲜的股骨髁上骨折11例.结果11例骨折全部愈合.骨折愈合时间平均14周.无内外翻畸形发生.根据Lysholm膝关节功能评分标准进行疗效评定,其中膝关节评分85～100分为优,70～84分为良好,60～69分为一般,小于60分为差.结果优8例,良2例,一般1例.差0例.优良率为90.91%.结论应用逆行交锁髓内钉治疗股骨髁上骨折是一个理想的方法,采用闭合复位内固定技术,更利于骨折愈合与膝关节功能恢复.     

Bone transport over an intramedullary nail for reconstruction of long bone defects in tibia

BACKGROUND: Although long bone defects may be treated by callus distraction, frequent complications arise from the long duration of external fixation. To reduce such complications, bone transport over an intramedullary nail (BTON) has been done for tibial bone defect. METHODS: In 12 patients (mean age, 46.1 years) of chronic osteomyelitis or bone defect, segmental transport was done using external fixator over an intramedullary nail. Prior to the index procedure, all patients had had serial debridements and five required myocutaneous or free flaps for covering of soft tissue defects. Using Mekhail's criteria, functional results were evaluated. RESULTS: The mean transported amount was 5.9 (range, 3.5-12) cm. The mean external fixation index was 26 days/cm, and healing index was 62.6 days/cm. The primary union of distraction and docking site was achieved in all, except for one failure in union at the docking site, which required another bone graft. Except for one patient with associated ankle injury, all had excellent or good functions. There was one recurrence of osteomyelitis and one procurvatum of the proximal tibia of 10 degrees . CONCLUSION: BTON may be a successful method in tibial reconstruction and allows patients to return to daily life earlier with relatively few complications.     

Finite element study of the proximal femur with retained trochanteric gamma nail and after removal of nail

This study aims to evaluate the stress and strain distributions in the healed proximal femur after fixation with a trochanteric gamma nail (TGN) and after TGN removal, using the finite element method. The stress distributions in the proximal femur with retained TGN and after TGN removal were very similar. The strain and the strain energy density in the femoral neck region with retained TGN were much higher than in the lag screw hole at the subtrochanter and the distal locking screw hole at the proximal femur, and even higher after TGN removal. Stair climbing resulted in higher strain and higher strain energy density at the femoral neck than normal walking. The conclusion can be drawn that removal of the TGN may result in high risk of femoral neck fracture.     

Stress analysis of a partially slotted intramedullary nail

A finite element analysis of the Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF) intramedullary femoral nail was performed to study the failure of the nail from circumferential cracking near the slot tip. These failures are evidently the result of a stress-concentrating effect owing to the partially slotted nail design. Several finite element models were created of the proximal one-fourth of the nail. One model of the nail incorporated the cloverleaf profile as it is presently manufactured, and one had a circular cross section. An additional three models were created with alternative slot-tip geometries: a narrowed slot, a tapered slot, and a widened slot. Antero-posterior (AP) and medio-lateral (ML) bending loads and torsion loads were applied in two fundamentally different loading modes: (1) loads that were applied on both sides of the slot tip (spanned); and (2) loads that were self-equilibrating distal to the slot tip (non-spanned). For the load cases studied, for all models, the stresses predicted from the finite element models were locally highest at the junction between the open and closed cross sections. Alternative slot-tip shapes had a marked effect on the predicted stresses, in one case reducing maximum stress by 40%. However, no alternative slot tip shape was uniformly superior for all load cases. Therefore, until the in vivo loading modes are known more precisely, an alternative slot-tip shape cannot be proposed.     

Medial sustainable nail versus proximal femoral nail antirotation in treating AO/OTA 31-A2.3 fractures: Finite element analysis and biomechanical evaluation

Objectives

Using finite element analysis and biomechanical tests, the biomechanical behaviors of Medial Sustainable Nail (MSN) and Proximal Femoral Nail Antirotation (PFNA) were compared for the fixation of fracture type of AO/OTA 31-A2.3.

Minimally invasive femoral nail extraction

Introduction Case report about a minimally invasive technique for removal of a femoral antegrade nail (FAN). Femoral nails are introduced by minimally invasive techniques, but are often removed with more invasive surgery.Materials and methods Four cases of young patients are described in whom the femoral nail was removed after consolidation by a minimally invasive extraction technique at the trochanteric site. By using a threaded wire for locating the proximal entrance of the femoral nail followed by reaming over the wire, the entrance of the nail in the trochanteric region is freed. Then the extraction bolt can be placed over the wire and the nail can be extracted through the same incision as it was inserted in, without enlarging the incision.Discussion This case report discusses a technique for minimally invasive femoral nail extraction, not the necessity of removing nails. Leaving out the endcap at the initial operation is the only preoperative condition, since the endcap blocks the entrance of the nail. This operation is done with fluoroscopic guidance. The difficult part is the reaming. The reamer must not be damaged when approaching the nail entrance. This minimally invasive femoral nail extraction technique is applicable for various types of femoral nails.Conclusion Minimally invasive extraction of femoral nails is possible and needs more attention. The level of evidence is a level IV case series.Concerning funding, there was no financial support for this report.     

Preliminary clinical and radiographic results with the Fixion intramedullary nail: an inflatable self-locking system for long bone fractures

We present a new inflatable self-locking intramedullary nailing system for the treatment of long bone fractures. The features of this system and the advantages of the technique include: fixation along the entire length of the nail, lack of proximal or distal interlocking screws, optional reaming, reduced exposure of the surgeon to X-ray and reduced operating room time. First preliminary clinical and radiographic results are reported. Out of 41 patients who received implants for closed fractures, 29 were available for follow-up. We observed fracture consolidation in all 29 cases (100%), with absence of nonunions, infections or rotational malalignments. Only in 2 (6.9%) cases were complication reported, consisting in the opening of the fracture after inflation of the nail. Good stability of the nail, however, assured a complete callus formation. We conclude that the use of this intramedullary nail is an innovative, effective, simple and minimally invasive treatment for long bone shaft fractures. Received: 17 January 2001/Accepted: 15 May 2001     

Intramedullary osteosynthesis of complex proximal femoral fractures with the Targon PF nail

We evaluated the performance of the Targon PF nailing system in the treatment of complex proximal femoral fractures with a retrospective analysis of prospectively collected data for 94 patients with a complex proximal femoral fracture (subtrochanteric fracture or fracture with reversed fracture line pattern) treated with a Targon PF nail. There were no intra-operative femoral fractures. Late complications requiring reoperation were one femoral fracture and one fracture around the nail secondary to tumour. Seven nails had to be dynamised and a further six 'self-dynamised' at the site of the distal locking screw. One patient required revision of the distal locking. Only one other patient required secondary surgery for a wound haematoma. There were no cases of implant cut-out or non-union. The Targon PF nail represents a progressive development in the design of intramedullary nails for proximal femoral fractures and the results compare favourably with other intramedullary systems used to treat complex proximal femoral fractures.     

外固定架结合髓内钉延长术治疗股骨缺损和不等长

目的探讨联合应用髓内钉及外固定架治疗股骨缺损和不等长的方法和疗效。方法2001年1月～2003年12月联合应用髓内钉及外固定架治疗2例股骨缺损分别为8 cm和11 cm的患者、3例股骨短缩为4～7 cm的患者。手术于股骨内顺行置入带锁髓内钉(或保留原有髓内钉),带锁髓内钉仅锁定一端,安装外固定架。4例于股骨近段截骨,1例于股骨远段截骨。5例患者中2例使用Ilizarov重建外固定架,3例使用Orthofix重建外固定架。术后平均延迟16．2 d(13～24 d)后开始牵开延长,1mm/d,共分4次完成。对于股骨短缩患者,当股骨达到预期延长长度后再次手术将髓内钉远端锁定,然后去除外固定架,开始早期功能锻炼。对于骨缺损患者,当股骨达到预期延长长度后仍须等待新生骨痂密度有所增加后将髓内钉远端锁定并去除外固定架。结果5例患者获平均36．4个月(22～47个月)随访,平均延长长度为7．2 cm (4～10 cm),外固定架放置时间平均为5个月(3～8个月),外固定架指数平均为0．75个月/cm(0．57～1．00个月/cm)。所有患者股骨延长段未出现轴向偏移或再骨折,坚实化良好。最后随访时,5例患者膝关节活动度平均为107°(80°～135°)。结论联合应用髓内钉及外固定架肢体延长术能够明显缩短外固定架置放时间,避免肢体畸形,有利于膝关节早期功能恢复,在治疗大段骨缺损及肢体不等长中具有一定优势。手术时间长、术中出血多、治疗费用高和手术切口瘢痕增加是其缺点。     

Failure of intertrochanteric nailing due to distal nail jamming

Nail impingement against the anterior femoral cortex during nail insertion, or anterior cortex penetration, has been described in the literature as a worrying complication. We describe a previously unreported surgical failure due to a compromised dynamic distal locking caused by distal jamming of the nail. An 80-year-old male suffered a closed right intertrochanteric femoral fracture. Due to the presence of a long medial fragment, a 240 mm long titanium trochanteric nail was chosen to stabilize the fracture. Dynamic distal locking was performed by placing the distal screw at the inferior rim of the elliptical locking hole to allow compression of the fracture site during weight-bearing. Six-month X-ray follow-up revealed a broken nail and nonunion of the fracture due to failed dynamization of the distal locking screw. The nail was removed and replaced by a total arthroplasty. Due to the femoral anterior bow of the shaft, anterior cortical impingement of the distal tip of a nail may result in the failure of the nail to slide within the diaphyseal canal when using a medium-length nail preventing compression of the fracture. Dynamic distal locking can be ineffective if the ability of the distal nail to slide within the diaphyseal canal is hindered. This type of scenario can represent an opportunity for anterior nail impingement. Distal jamming of the nail can thus compromise dynamic compression at the fracture site during loading, thus inducing nonunion of the fracture, and leading to breakage of the osteosynthesis device. For these reasons, caution is recommended when using medium-length trochanteric nails for unstable trochanteric fractures.     

Maisonneuve骨折手术治疗13例

Maisonneuve骨折是一种特殊类型的踝部旋前外旋型骨折,包括下胫腓联合分离,内踝骨折,腓骨高位螺旋型骨折,位置可高达腓骨颈.我院自1994年至今共手术治疗13例,取得满意疗效,现报告如下. 1 临床资料 本组13例,男9例,女4例.年龄最大48岁,最小21岁.扭伤5例,交通事故6例,运动损伤2例.受伤到就诊时间30分钟～6天. 2 治疗方法 本组13例全部采用连硬外麻醉下,行手术切开复位.先固定腓骨,再固定下胫腓联合,最后固定内踝.8例腓骨骨折端重叠超过5mm,用4孔或5孔钢板固定;5例骨折端重叠移位在3mm以下,行克氏针固定.用1～2枚螺钉固定分离的下胫腓联合和胫腓下段,内踝骨折用1枚螺钉固定.术后石膏固定4周,8周开始拄拐逐渐负重锻炼,10～12周取出内固定物.