Intramedullary nailing of the femur with an inflatable self-locking nail: comparison with locked nailing

We report a comparative study between an inflatable expandable nail and a traditional locked intramedullary implant in closed fractures of the femoral shaft. We matched each of 43 patients who had undergone intramedullary fixation with an inflatable expandable nail with a patient of the same sex, age (within 2 years), and fracture who had undergone statically locked intramedullary fixation with traditional nails. The mean duration of surgery was significantly shorter in the patients who were treated with the inflatable expandable nail. There were no differences in average blood loss, transfusion requirements, or hospitalization. Five of the patients who underwent traditional nailing required dynamization to achieve union. The inflatable expandable nail allows effective management of diaphyseal fractures of the femur. Interlocking is not necessary, operative times are reduced, and exposure to ionizing radiation is minimized. At present, however, the inflatable expandable nail used in the this investigation is markedly more expensive than traditional devices.     

Treatment of proximal humeral fractures with Polarus nail fixation

A chart review of 20 patients who sustained acute proximal humeral fractures and who were treated by surgical stabilization with locked antegrade humeral intramedullary nails (Polarus nails) was undertaken. The clinical outcome measurements were fracture healing, infection, and neurologic injury. Radiologic outcome measurements included fracture alignment, loosening, fixation and hardware failure, and malunion and nonunion. Of 20 fractures, 11 healed without complications. The mean immediate postoperative and final radiographic valgus neck/shaft angulation measured 131 degrees. Of the 20 implants, 3 had proximal fixation screw loosening. Of the 20 implants, 2 underwent revision surgery for proximal fixation failure. With certain fracture types, the Polarus intramedullary humeral nail can be an effective implant. In fracture cases involving an unstable or comminuted lateral metaphyseal fracture, if the starting point extends into the greater tuberosity, fixation failure or fracture displacement may result.     

可膨胀自锁型髓内钉治疗肱骨干骨折

[目的]探讨闭合复位、可膨胀自锁型髓内钉固定在肱骨干骨折治疗中的临床效果.[方法]自2006年9月-2008年12月,应用可膨胀自锁型髓内钉治疗肱骨干骨折10例,其中男6例,女4例,年龄21～75岁,平均38.3岁.骨折按AO分类:12A1型3例,12A2型5例,12A3型2例,均采用闭合复位,顺行插钉.[结果]10例患者均获随访,时间9～22个月,平均随访时间14个月.10例患者均获得临床骨性愈合,平均愈合时间为11周.肘关节功能正常.肩关节功能按Neer疗效评分系统评定:优7例,良2例,可1例,优良率为90.0%.术后无感染、脂肪栓塞、骨折延迟愈合、不愈合、肢体短缩和旋转畸形等并发症的发生.[结论]可膨胀自锁型髓内钉治疗肱骨干骨折具有微创、操作简单、固定坚强、对骨折局部血供破坏小、取出方便等优点,是一种疗效满意的方法.     

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.     

Expandable intramedullary nails in lower limb trauma: a systematic review of clinical and radiological outcomes

This study systematically reviews the evidence-base for the use of expandable nails in the treatment of acute diaphyseal fractures of the lower limb. Both electronic and hand searches were undertaken of the published and grey literature to 1 December 2011. A total of 154 citations were identified, of which 15 were deemed suitable and assessed with the Critical Appraisals Skills Programme tool. A total of 625 nailing procedures were performed in 620 patients: 279 femoral and 346 tibial nails. The expandable nail was found to be significantly quicker to insert than interlocked nails (p < 0.05), and the total incidence of non-union or other complication was 13 and 14 % for expandable femoral and tibial nails, respectively. Notable complications with the expandable nail included fracture propagation on nail inflation in 2.5 % and post-operative shortening in 3.3 %. Device failure secondary to problems with the expansion mechanism was seen in 2.9 %. The rate of non-union and infection following expandable nailing was 3.1 and 1.4 %, respectively. Despite promising initial results, there remains a paucity of good quality studies to support the use of expandable nails over interlocked nails for the treatment of acute diaphyseal fractures of the lower limb.     

Locked nailing with interfragmentary wiring for humeral nonunions

OBJECTIVE: Locked nailing for humeral nonunions is threatened by residual fracture gap and fracture motion. This article describes the clinical experience of using interfragmentary wiring to solve these problems. METHODS: Interfragmentary wiring was used in 21 consecutive humeral nonunions treated with humeral locked nails. The average age of patients was 49.5 years, with an average nonunion duration of 14.4 months. Eighteen patients had previous operations. Nonunions were located at the proximal third in 4, the middle third in 10, and the distal third in 7. Antegrade nailing was used in 11 and retrograde nailing in 10. Sixteen nonunions were nailed with 8-mm nails and five with 7-mm nails. Interfragmentary wiring was applied to either the posterior or the lateral cortex of humeri in a figure-of-eight configuration. Bone grafting was performed in all and average follow-up time was 22 months. RESULTS: With a single operation, all patients achieved osseous union in, on average, 18.3 weeks. One patient with segmental nonunion suffered acute renal failure 4 months after operation, but fracture healing was not affected. Wire infection occurred in one patient with preoperative infection at the nail entry site and was treated by implant removal. Other complications including two transient radial nerve palsies and one brachial artery injury did not affect the final outcome. At follow-up, all but four patients had complete recovery of shoulder flexion and abduction. The average postoperative Neer score (91.1 points) was significantly better than the average preoperative score (65.5 points). All but three patients had complete recovery of elbow motion. CONCLUSION: Interfragmentary wiring, a safe procedure if properly performed, could effectively decrease the residual fracture gap and fracture motion in locked nailing of humeral nonunions. Further biomechanical studies and prospective, randomized, controlled studies are warranted.     

The use of elastic nails for intramedullary fixation of humeral fractures and nonunions

From May 1993 to January 1997, a total of 130 humeral fractures and nonunions were treated using an "elastic" unreamed nail. The elastic nail consists of a cylindrical proximal component tapered for the application of the impactor-extractor, distally containing the proximal ends of four or five secondary nails preloaded to diverge and held together by a retaining system. The surgical approach is through the olecranic fossa apex. Once introduced, the proximal end of the nail locks automatically by diverging the secondary nails in the proximal humeral epiphysis. Distally, the elastic nail is locked with a crossbolt. The elastic nail enables stable fixation of fractures or nonunions and allows early rehabilitation.     

Treatment of humeral shaft delayed unions and nonunions with humeral locked nails

OBJECTIVE: To report experience with use of humeral locked nails in treating humeral delayed unions and nonunions. The following techniques yielded encouragingly good results: static locking, short-to-long segment nailing, bone grafting, fracture compression, and minimal surgical trauma. DESIGN AND METHODS: A total of 41 consecutive patients with 13 delayed unions and 28 nonunions were treated with humeral locked nails. Delay from trauma to surgery averaged 4.2 months for delayed union and 15.5 months for nonunion. The average age of patients was 50.2 years; average follow-up time was 23.2 months. There were 7 proximal-third fractures, 21 middle-third fractures, and 13 distal-third fractures. The antegrade approach was used for 13 fractures and retrograde for 28. Open nailing was performed in 39 fractures and closed nailing in 2. If the fracture motion was still present after nail insertion, axial compression of the fracture site was specially applied. Bone grafting was performed in the fractures with open nailing. Thirty-four fractures were nailed with 8-mm nails, and 7 fractures were nailed with 7-mm nails. RESULTS: With a single operation, all but two patients achieved osseous union in, on average, 5.6 months. One of these two patients eventually gained union after another surgery with fracture compression along the original nail and concurrent bone grafting. The second patient, undergoing hemodialysis for chronic renal failure, had persistent nonunion. At follow-up, for patients with antegrade nailing, all but four patients had less than 20 degrees limitation of shoulder abduction. For patients with retrograde nailing, all but two had less than 10 degrees limitation of elbow motion. Only the patient with persistent nonunion had continual pain and significant impairment of arm function. CONCLUSIONS: Humeral locked nailing seems to be effective for humeral delayed unions or nonunions. It may be an acceptable alternative for fractures unsuited for plate fixation, such as those with comminution, osteoporosis, or a severely adhered radial nerve.     

Retrograde nailing of a femoral supracondyle

Because standard femoral supracondylar nails have certain disadvantages, they are often replaced by traditional femoral or tibial locked nails. The purpose of this study was to make a biomechanical comparison between both types of traditional locked nails to determine which technique was more suitable for treating unstable femoral supracondylar fractures. Fourteen left Sawbones femurs (Pacific Research Laboratories, Vashon, Washington) were osteotomized in the femoral supracondylar area. One centimeter of the medial cortex in the proximal fragment was obliquely removed to simulate an unstable fracture without shortening. Seven specimens were treated with traditional retrograde dynamic femoral locked nails, and the other 7 with traditional retrograde dynamic tibial locked nails. All specimens were tested with a servohydraulic materials testing machine to compare their relative stability. Static compression, dynamic cyclic compression, and static compression to failure were tested. An extensometer was used to measure the displacement of fragments. Displacement between the fragments increased following the increment in loads in both nails. The load-displacement curve was nearly linear up to 1000 N for both nails. The femoral nail had a greater stiffness compared with the tibial nail at 100 and 200 N (P=.02 and P=.04, respectively) in static compression and at 700 to 1000 N (P=.01 in each case) in dynamic cyclic compression, as well as larger loads in static compression to failure (8663 vs 7547 N, respectively; P<.001). Clinically, a traditional femoral locked nail may be more suitable to replace a standard femoral supracondylar nail in a retrograde fashion to treat an unstable femoral supracondylar fracture.     

Antegrade locked nailing for humeral shaft fractures

Treatment results of antegrade locked nailing of acute humeral shaft fractures, including union rate and recovery of shoulder function, have been inconsistent. This led the current authors to hypothesize that implant design and surgical techniques might account for this inconsistency. In the current study, 47 fractures (38 acute; nine pathologic) in 47 patients achieved union with the techniques of closed nailing, short to long segment nailing, and fracture compression. Satisfactory recovery of shoulder function occurred because of minimal surgical trauma, prevention of impingement by the nail or locking screws, and prevention of axillary nerve injury or comminution of the humeral head. Forty-seven patients with 38 acute fractures and nine pathologic fractures were treated with humeral locked nails. Mean followup time was 21.4 months. With a single operation, all 38 acute fractures proceeded to eventual union; the average time to union was 7.8 weeks. Thirty-five patients had excellent or satisfactory recovery of shoulder function. Complications included slipout of the proximal screw, nail breakage, fragment displacement, and transient postoperative radial nerve palsy. All nine patients with pathologic fractures had substantial pain relief and increased arm function after surgery. The current study shows the reliability of antegrade locked nailing for proximal and middle third fractures of the humeral shaft.     

The effect of locked distal screws in retrograde nailing of osteoporotic distal femur fractures: a laboratory study using cadaver femurs

OBJECTIVES: To examine the effects of locked distal screws in retrograde nails used in unstable osteopenic distal femur fractures. DESIGN: Biomechanical testing of paired human cadaveric femurs. INTERVENTION: Seven matched pairs of embalmed, moderately osteopenic cadaver femurs were instrumented with 12-mm intramedullary nails in a statically locked, retrograde fashion. One femur of each pair had locked distal screws and the other femur had unlocked distal screws. A 2.5-cm gap of bone was cut nine centimeters from the distal condyles to simulate an unstable fracture. The locked distal screw nails were compared to unlocked distal screw nails for collapse of the fracture gap, medial-lateral and anterior-posterior translation of the nail within the fracture site, and fracture angulation. The femurs were axially loaded, cycled, and then loaded to failure. MAIN OUTCOME MEASURES: Motion at the fracture site with axial cyclic loading and site of failure when loaded to failure. RESULTS: After cycling, both locked distal screw and unlocked distal screw nails demonstrated several millimeters medial and anterior translation within the fracture site and approximately 1 mm collapse of the fracture gap. Although no statistically significant differences were found, the locked distal screw nails had less anterior and medial translation, angulation, and collapse of the fracture gap after cycling. Loads to failure were similar for both locked distal screw and unlocked distal screw nails. It was noted that proximal femur failure occurred at the level of the proximal screw hole in the nail at the subtrochanteric level in 7 (4 locked distal screws and 3 unlocked distal screw groups) of the 14 samples. Four other samples failed through the intertrochanteric region (2 locked distal screw and 2 unlocked distal screw groups) and the remainder within the distal fragment by fracture of the femur along the medial cortex. CONCLUSIONS: Although most differences in fixation stability were not significant, the locked distal screw nails exhibited less fracture collapse and anterior and medial translation of the nail at the fracture site than the unlocked distal screw nails. The degree of varus angulation after cyclic loading was also less for the locked distal screw nails. The length of the nail chosen should avoid having proximal locking screws distal to the lesser trochanter, thus averting proximal femur stress risers and fractures.     

Expandable intramedullary nailing for tibial and femoral fractures: a preliminary analysis of perioperative complications

OBJECTIVE: To report the results of using the expandable nailing system in the treatment of femoral and tibial shaft fractures. DESIGN: Prospective, cohort series. SETTING: Two level-1 university trauma centers. PARTICIPANTS: Forty-eight patients with acute, traumatic diaphyseal fractures of the tibia or femur. INTERVENTION: Internal fixation of lower extremity long bone fractures using expandable intramedullary nailing. MAIN OUTCOME MEASUREMENTS: Perioperative complications and time to healing. RESULTS: Forty-nine long bone fractures were treated: 22 femoral fractures (OTA classification: 4 type A1, 6 A2, 7 A3, 1 B1, and 4 B2) and 27 tibial fractures (OTA classification: 4 type A1, 11 A2, 9 A3, 0 B1, and 3 B2). There were 13 open fractures and 37 closed fractures. Healing occurred in 37 (75%) fractures without additional interventions. There were 2 tibial delayed unions and 1 femoral and 1 tibial nonunion. Five tibial shaft fractures and 6 femoral fractures shortened by 1.0 cm or more postoperatively. In 3 tibias and 4 femurs, shortening occurred after fractures judged to be length-stable became unstable because of fracture propagation during nail expansion. Five tibias and 3 femurs were converted to standard locked nails because of shortening. The average time to healing, excluding nonunion, was 15 weeks in the tibia and 16 weeks in the femur. The expandable nail resulted in an unplanned reoperation in 12 cases (25%). CONCLUSION: We found a high complication rate because of shortening, which was independent of fracture classification. Consequently, we cannot recommend the use of an unlocked, expandable nail in diaphyseal fractures of the femur or tibia.     

Is distal locking of long nails for intertrochanteric fractures necessary? A clinical study

Background

Few clinical studies have examined the utility of distal interlocking nails when fixing intertrochanteric fractures with intramedullary devices. In this study we performed a retrospective analysis comparing fixation method of intertrochanteric fractures with either a long unlocked cephalomedullary nail versus a long locked cephalomedullary nail. Our hypothesis was there would be no difference in device related failures or complications in stable intertrochanteric fractures treated with long locked or long unlocked cephalomedullary nails.

Methods

A retrospective chart review was performed of all stable intertrochanteric fractures treated with a long cephalomedullary nail between 2006 and 2012 at our institution. Clinical history as well as perioperative radiography was carefully reviewed for all subjects. AO classification, the use of locked or unlocked technique, and failure status was recorded.

Results

Overall, a device related failure rate of 1.8% (2/107) was observed for stable intertrochanteric fractures treated with long cephalomedullary nails. No statistical difference in failure rate was found between locked and unlocked nails within our studied population (0% long locked (0/56) versus 3.9% long unlocked (2/51), p = 0.224).

Conclusion

This clinical study supports our hypothesis that long cephalomedullary nails do not need to be locked for stable intertrochanteric fractures. We found no difference in failure rates between the two approaches across 107 patients.     

Biomechanical performance of locked intramedullary nail systems in comminuted femoral shaft fractures

The biomechanical properties of commercially available locked nail systems designed for use in comminuted femoral shaft fractures were compared and evaluated. Ender nails as well as three forms of interlocking nails, Brooker-Wills (B-W), Klenm-Schellman (K-S), and Grosse-Kempf (G-K), were implanted in cadaver femora. The femora were tested in torsion, bending, and axial loading to failure. Two fracture models were tested--a 3 cm subtrochanteric defect and an 8 cm midshaft defect. Results of the testing revealed the three interlocking nails to be comparable to each other and superior to Ender nails in bending and torsion. However, the distally bolted locked nails (K-S, G-K) resisted significantly higher loads than either the distally bladed locked nail (B-W) or Ender nails when tested to failure by axial loading.     

Treatment of acute tibial shaft fractures with an expandable nailing system: a systematic review of the literature

Locked Intramedullary Nailing is an established method of treatment for tibial shaft fractures. Locking of tibial nails is however not without its drawbacks. Locking is time consuming, and is associated with a noteworthy complication rate. The Fixion IM nailing system is an expandable nail designed to eliminate some of these drawbacks. We have performed a systematic review of the literature to determine the safety and efficacy of this system. Publications examining the use of the Fixion system were identified from the MEDLINE and the Cochrane databases. Forty-one citations were generated by the MEDLINE search. Of these, two quasi-randomised trials and eight case series satisfied our selection criteria and were reviewed. Overall the average reoperation rate for the Fixion nail was 10.2%. Shortening occurred in 3% of cases and fracture propagation was reported in 2% of cases. The Fixion cohort united at an average of 12.2 weeks and the average operative time was 54 minutes. The Fixion system eliminated complications and reoperations associated with the use of locking screws. Further studies in the form of randomised controlled trials are needed to evaluate the Fixion system against conventional locked nails.     

Treatment of femoral shaft fractures with a titanium intramedullary nail

Ninety-nine femoral shaft fractures were treated with locked intramedullary nails made from titanium alloy. One of the distal interlocking screws failed in six fractures (6%) and both screws failed in two fractures (2%). Delayed union was associated with all of the eight fractures that had locking screw failure. Young, heavier patients who had nails of small diameter had an increased risk of screw failure. Additional surgery was needed when both screws failed. The authors still use this nail, but currently prefer to ream the medullary canal more so that larger nails can be inserted. Decisions concerning weightbearing are made on an individual basis for each patient, and currently full weightbearing is delayed for young, active, and heavy patients. Two distal interlocking screws should be inserted for treatment of femoral shaft fracture when a Ti locked intramedullary nail is used.     

三种交锁髓内钉治疗胫骨骨折疗效比较

目的：评价静力扩髓型、动力扩髓型和动力不扩髓型三种类型的交锁髓内钉对胫骨骨折的疗效。方法：骨折类型采用AO骨折分型法，A型18例，B型32例，C型12例，共62例，均采用切开复位内固定治疗方法。结果：62例均获得随访，平均随访时间为13个月。根据胫骨干骨折治疗最终效果的评价标准评价术后功能，优46例，良11例，一般4例，差1例。结论：A型骨折三种髓内钉比较，骨折愈合时间有非常显著性差异；B型骨折三种髓内钉愈合时间比较，其中扩髓型与不扩髓型有非常显著性差异，而扩髓型中静力型与动力型间无显著性差异；C型骨折静力扩髓型与动力不扩髓型愈合时间比较，有非常显著性差异。术中宜尽量避免扩髓，并以采用不扩髓钛合金三角形交锁钉为佳。     

交锁髓内钉治疗肱骨干骨折的疗效分析(附58例回顾性分析)

目的评价采用交锁髓内钉治疗肱骨干骨折的临床效果。方法对58例肱骨干骨折采用闭合复位或有限切开复位交锁髓内钉固定并随访10～16个月。结果58例中57例骨折愈合,有1例骨折延迟愈合经取除远端锁钉动力化后骨折愈合,平均愈合时间为12周。肩关节功能按Neer评分,优38例,良15例,可5例,优良率为91.4%。结论肱骨交锁髓内钉对骨折端的血运影响较小、固定牢靠,是治疗肱骨干骨折的有效方法。     

The effect of concurrent fibular fracture on the fixation of distal tibia fractures: a laboratory comparison of intramedullary nails with locked plates

OBJECTIVE: To compare the fixation stability of intramedullary nails to that of locked plates for the treatment of distal metaphyseal tibia and fibula fractures. METHODS: A simulated, distal metaphyseal tibia fracture was created in 8 pairs of cadaveric tibia-fibula specimens. One of each pair was treated using an intramedullary nail (Trigen IM Nail System; SN Richards, Memphis, TN) and the other with a locked plate (Peri-Loc Periarticular Locked Plating System; SN Richards). Each specimen was vertically loaded to 250 N in central, anterior, posterior, medial, and lateral locations; loaded to 250 N in cantilever bending in anterior to posterior and posterior to anterior directions; and loaded to 250 N mm in torsion. Load-displacement curves were generated to determine the construct stiffness for each loading scenario, with comparisons made between the 2 treatment groups. Each specimen was then cyclically loaded with 750 N vertical loads applied for 10, 100, 1000, and 10,000 cycles. Measurements of fracture displacements were made and compared between treatment groups. A fibular osteotomy was then created in each specimen at the same level as the tibia fracture to simulate a same-level tibia-fibular fracture. Torsional stiffness assessment and cyclic vertical loading for 10, 100, 1000, and 10,000 cycles were repeated and fracture displacement measurements were again obtained. RESULTS: The locked plate construct was stiffer than the intramedullary nail construct for central, anterior, and posterior loading scenarios (P < 0.005, P < 0.03, and P < 0.02, respectively). The intramedullary nail construct was stiffer than the locked plate construct for both anterior to posterior and posterior to anterior cantilever bending (P < 0.03 and P < 0.02, respectively). No statistically significant difference in stiffness was noted between treatment groups for medial and lateral vertical loading or for torsional loading (P = 0.09, P = 0.32, and P = 0.84, respectively). There was no significant difference between treatment groups with respect to fracture displacement after cyclic vertical loading. After creation of the fibular osteotomy fracture, construct displacements after 1000 and 10,000 cycles significantly increased and torsional stiffness significantly decreased for both treatment groups. The locked plate constructs had significantly less displacement after cyclic loading of 1000 and 10,000 than the locked nail constructs (P < 0.001 and P < 0.0001, respectively). Locked plate constructs were stiffer in torsion after osteotomy than the intramedullary nail constructs (P < 0.05). CONCLUSION: This study demonstrated that, in the treatment of distal metaphyseal tibia fractures, locked plates provided more stable fixation than intramedullary nails in vertical loading but were less effective in cantilever bending. An intact fibula in the presence of a distal tibia fracture improved the fracture fixation stability for both treatment methods. In fracture patterns in which the fibula cannot be effectively stabilized, locked plates offer improved mechanical stability when compared with locked intramedullary nails.