Elastic stable intramedullary nailing for unstable femoral fractures in children: preliminary results of a new method

Retrospective, multicenter evaluation of complications in the treatment of diaphyseal femur fractures in pediatric patients

INTRODUCTION

Femoral shaft fractures are the commonest major pediatric fractures. For generations, traction and casting were the standard method of treatment for children. However, over the past two decades there has been growing recognition of the advantages of fixation and rapid mobilization.

METHODS

A prospective multicenter study was conducted at four Italian centers of reference for pediatric fractures (January 2005 to December 2014). The study involved 62 patients of both sexes, between 6 and 14 years of age, with closed femoral shaft fractures. The aim was to find out more about the short-term complications of titanium elastic nailing in diaphyseal femur fractures in children in order to reduce them.

RESULTS

The commonest complication observed in our study was pain at the nail entry point (24.19%) due to a local inflammatory reaction. After 1 year, 3.22% had limbs of different lengths. Proximal migration occurred in 1.61% of cases.

DISCUSSION

Over the last two decades, the treatment of femoral shaft fractures in pediatric patients has developed to include internal fixation using Titanium Elastic Nails (TEN). We only observed a few complications in our study, most of which were minor and associated with the surgical technique employed, particularly during the initial phase of the surgeon's learning curve.

CONCLUSIONS

TEN are an excellent internal fixation system if used by an expert surgeon and have a very low rate of complications. None of them produced permanent damage in the patients. In older children weighing more than 50 kg, alternative techniques such as subtrochanteric nailing, plates, or external fixation are advisable.

Retrograde Stainless Steel Flexible Nails Have Superior Resistance to Bending in Distal Third Femoral Shaft Fractures

BACKGROUND

It has been shown that retrograde titanium flexible intramedullary nails (Ti FIN) provide superior resistance to bending compared to antegrade Ti FIN in distal femur fractures. The purpose of this study was to compare resistance to torsional and bending forces of stainless steel (SS) FIN, with or without a locking screw, and Ti FIN in distal third femoral shaft fractures. We hypothesize that locked retrograde SS FIN will demonstrate greater resistance to both bending and torsional forces.

METHODS

Thirty adolescent synthetic femur models were used to simulate transverse distal femoral fractures at either 60 mm or 90 mm proximal to the distal femoral physis. The femurs were instrumented with antegrade Ti FIN, antegrade SS FIN, retrograde Ti FIN, retrograde SS FIN, or retrograde locked SS FIN. Three models for each construct at both osteotomy levels were tested. Models were analyzed to determine maximum resistance to bending and torsion.

RESULTS

In fractures 60 mm from the physis, retrograde SS FIN demonstrated statistically superior resistance to bending when compared with both antegrade and retrograde Ti FIN (P=0.001 and 0.008, respectively) and antegrade SS FIN (P=0.0001). Locked SS constructs showed a trend towards greater resistance to bending forces when compared with unlocked constructs (P>0.05). No significant difference was seen in resistance to bending when fractures were 90 mm proximal to the distal femoral physis between the five groups. No significant differences were observed in resistance to torsion in either the proximal or distal fracture models, regardless of construct type.

CONCLUSIONS

Retrograde SS FIN confer significantly greater resistance to bending forces for fractures 60 mm proximal to the distal femoral physis compared with Ti FIN or antegrade entry SS FIN. In fractures 90 mm from the physis, no differences were noted in our model. Our results support the use of retrograde SS nails in the pediatric patient with distal femoral shaft fractures.

LEVEL OF EVIDENCE

Level II-comparative biomechanical study.

Flexible Intramedullary Nails for Femur Fractures in Pediatric Patients Heavier Than 100 Pounds

BACKGROUND

Flexible intramedullary nailing (FIMN) of femoral shaft fractures in children >100 pounds remains controversial. The purpose of this study is to assess the relationship between patient weight and alignment at radiographic union following Ender's FIMN of pediatric femoral shaft fractures.

METHODS

An IRB approved, retrospective review of all patients who sustained a femoral shaft fracture treated by retrograde, stainless-steel Ender's FIMN was performed at a level 1 pediatric trauma center from 2005 to 2012. Preoperative radiographs were analyzed to determine fracture pattern, location, and isthmic canal diameter. Patient weight was measured on presentation to the emergency room. Radiographs at bony union were reviewed to measure shortening, coronal angulation, and sagittal angulation.

RESULTS

A total of 261 children underwent Ender's FIMN for femoral shaft fractures during the study period. There were 24 patients who weighed ≥100 lbs and 237 patients who weighed <100 lbs. There were no significant differences in sex (75% vs. 73% male), fracture stability (42.6% vs. 41.7% length unstable), or fracture patterns between the 2 groups. The ≥100 lbs group was significantly older (10.6 vs. 8.0 y, P<0.001). There were no significant differences in final coronal angulation (1.5 vs. 3.0 degrees), sagittal angulation (2.8 vs. 3.1 degrees), or shortening (3.4 vs. 3.5 mm) between the 2 groups. There were significantly more nail removals in the <100 lbs group (81.4% vs. 66.7%, P<0.01). Four percent of the population (10 patients) weighed ≥120 lbs and aside from age (11.4 vs. 8.1 y, P<0.01), there were no significant demographic or fracture pattern differences between this group and the remaining population. This heaviest group demonstrated no significant difference in shortening (3.3 vs. 3.5 mm), coronal angulation (0.8 vs. 3.0 degrees), or sagittal angulation (0.7 vs. 3.2 degrees) at radiographic union when compared with the lighter patients.

CONCLUSIONS

Stainless-steel Ender's FIMN is an effective treatment for pediatric femoral shaft fractures in patients ≥100 pounds with excellent radiographic outcomes and no increased risk for malunion.

LEVEL OF EVIDENCE

Therapeutic Level III.

V, RHH A, Khurana A. Current Concepts in Paediatric Femoral Shaft Fractures

Pediatric femoral shaft fractures account for less than 2% of all fractures in children. However, these are the most common pediatric fractures necessitating hospitalization and are associated with prolonged hospital stay, prolonged immobilization and impose a significant burden on the healthcare system as well as caregivers. In this paper, the authors present a comprehensive review of epidemiology, aetiology, classification and managemement options of pediatric femoral shaft fractures.

Biomechanical investigation of titanium elastic nail prebending for treating diaphyseal long bone fractures

This study numerically investigated the deformation of titanium elastic nails prebent at various degrees during implantation into the intramedullary canal of fractured bones and the mechanism by which this prebending influenced the stability of the fractured bone. Three degrees of prebending the implanted portions of the nails were used: equal to, two times, and three times the diameter of the intramedullary canal. Furthermore, a simulated diaphyseal fracture with a 5-mm gap was created in the middle shaft portion of the bone fixed with two elastic nails in a double C-type configuration. End caps were simulated using a constraint equation. To confirm that the simulation process is able to present the mechanical response of the nail inside the intramedullary, an experiment was conducted by using sawbone for validation. The results indicated that increasing the degrees of nail prebending facilitated straightening the nails against the inner aspect of canal after implantation, with increase in stability under torsion. Furthermore, reducing nail prebending caused a larger portion of the nails to move closer to the loading site and center of bone after implantation; the use of end caps prevented the nail tips from collapsing and increased axial stability. End cap use was critical for preventing the nail tips from collapsing and for increasing the stability of the nails prebent at a degree equal to the diameter of the canal with insufficient frictional force between the nail and canal. Therefore, titanium elastic nail prebending in a double C-type configuration with a degree three times the diameter of the canal represents a superior solution for treating transverse fractures without a gap, whereas that with a degree equal to the diameter of the intramedullary canal and combined with end cap use represents an advanced solution for treating comminuted fractures in a diaphyseal long bone fracture.

Advanced interlocking systems to improve heavy-load-bearing characteristics of flexible intramedullary nailing

Flexible intramedullary nailing (FIN) is a minimally invasive and widespread standard method for osteosynthesis of pediatric long bone fractures. In the case of unstable fractures of the lower extremity, interlocking systems need to be used to prevent axial shortening and subsequent perforation of the nail at its insertion site. In the present study, four different screw-fixed interlocking systems for FINs (Hofer TwinPlug with two 3-mm titanium interlocking screws, Hofer FixPlug with 3-mm titanium interlocking screw, Hofer Plug with 3.5-mm titanium interlocking screw, and Hofer Plug with 3-mm titanium interlocking screw) in comparison with the commonly used Ender stainless steel nails (locked with 3.5-mm screw) were experimentally investigated in cadaveric lamb tibiae, regarding their load characteristics and failure modes in the case of heavy loading. The specimens were subjected to sequential axial cyclic loading of 5000cycles with stepwise increase of the load amplitude until failure. Migration of locking screws and internal damage of bone tissue was quantified by micro-computed tomography (CT) imaging. Ender nails failed on average at a peak load of 800 N, TwinPlugs at 1367 N, FixPlugs at 1222 N, Plugs 3.5mm at 1225 N and Plugs 3.0mm at 971 N. TwinPlugs, FixPlugs, and Plugs 3.5mm failed in a slow manner over several hundred loading cycles, whereas Ender nails and Plugs 3.0mm exhibited abrupt failure without any prior indication. Our results confirm that axial stability of FIN can be further improved by screw-fixed plugs by simultaneously avoiding shortcomings of an eye-locked system, which the Ender nails are. Considering biomechanical results, plug interlocking systems with 3.5-mm screws should be favored over conventional Ender nails and plugs with 3-mm screws.

Pediatric Trauma: Current Concepts and Treatments

Injured children represent a complex management problem for the trauma surgeon. Physiologic and psychological factors have been shown to influence outcome; however, more importantly, injury patterns and treatment algorithms differ from those recommended for adults. Children often do well after major injuries, but surgeons must use appropriate treatment to maximize the physiologic responses and the innate healing abilities of the growing child. Historically, surgeons have defined childhood as prepubertal, but a child's physiologic response to injury extends well into the third decade of life, making treatment of a 20-year-old similar to that of a 10-year-old, rather than that of a 40-year-old. The distribution of pediatric trauma facilities across the country has limited the access of the injured child to these centers. Adult centers more often serve as the first and definitive treatment provider for children. This article reviews the current concepts of trauma treatments for children. It is hoped that the adult trauma surgeons caring for injured children might gain information that will be of assistance in their daily practice.

Complications of Elastic Stable Intramedullary Nailing for treating paediatric long bone fractures

This study reports the complications observed in children with long bone fractures treated using Elastic Stable Intramedullary Nailing (ESIN). One hundred and sixty-four (n = 164) fractures in 160 patients under the age of 16 years formed the basis of our review. This included 108 boys and 52 girls with the median age of 11 years and median follow up of 7.5 months. The analysis included fractures of the radius/ulna, humerus, femur and tibia. All pathological fractures were excluded. In this series 54 patients (34%) had complications however majority of these were minor complications with irritation due to prominent nail ends being the commonest complication. No long-term sequelae were encountered in our patients.

Risk factors for overgrowth after flexible intramedullary nailing for fractures of the femoral shaft in children

We analysed retrospectively the risk factors leading to femoral overgrowth after flexible intramedullary nailing in 43 children (mean age 7.1 years (3.6 to 12.0)) with fractures of the shaft of the femur. We reviewed their demographic data, mechanism of injury, associated injuries, the type and location of the fractures, the nail–canal diameter (NCD) ratios and femoral overgrowth at a mean follow-up of 40.7 months (25.2 to 92.7). At that time, the children were divided into two groups, those with femoral overgrowth of < 1 cm (Group 1), and those with overgrowth of ≥ 1 cm (Group 2). The mean femoral overgrowth of all patients was 0.6 cm at final follow-up. Overgrowth of ≥ 1 cm was noted in 11 children (25.6%). The NCD ratio was significantly lower in Group 2 than in Group 1, with an odds ratio of 30.0 (p = 0.003).

We believe that a low NCD ratio is an indicator of an unstable configuration with flexible intramedullary nailing, and have identified an association between a low NCD ratio and femoral overgrowth resulting in leg-length discrepancy after flexible intramedullary nailing in paediatric femoral shaft fractures.

Cite this article: Bone Joint J 2013;95-B:254–8.

Biomechanical performance of flexible intramedullary nails with end caps tested in distal segmental defects of pediatric femur models

BACKGROUND

Unstable distal femoral fractures in children are challenging lesions with restricted surgical options for adequate stabilization. Elastic nails have become popular for treating femoral shaft fractures, yet they are still challenging for using in distal fractures. The aim of this study was to test whether end caps (CAP) inserted into the nail extremity improved the mechanical stabilization of a segmental defect at the distal femoral metaphyseal-diaphyseal junction created in an artificial pediatric bone model.

METHODS

Two 3.5-mm titanium elastic nails (TEN) were introduced intramedullary into pediatric femur models, and a 7.0-mm-thick segmental defect was created at the distal diaphyseal-metaphyseal junction. Nondestructive 4-point bending, axial-bending, and torsion tests were conducted. After this, the end caps were inserted into the external tips of the nails and then screwed into the bone cortex. The mechanical tests were repeated. Stiffness, displacement, and torque were analyzed using the Wilcoxon nonparametric test for paired samples.

RESULTS

In the combined axial-bending tests, the TEN+CAP combination was 8.75% stiffer than nails alone (P<0.01); in torsion tests, the TEN+CAP was 14% stiffer than nails alone (P<0.01). In contrast, the 4-point bending test did not show differences between the methods (P=0.91, stiffness; P=0.51, displacement). Thus, the end caps contributed to an increase in the construct stability for torsion and axial-bending forces but not for 4-point bending forces.

CONCLUSIONS

These findings indicate that end caps fitted to elastic nails may contribute to the stabilization of fractures that our model mimics (small distal fragment, bone comminution, and distal bone fragment loss).

CLINICAL RELEVANCE

Type II [therapeutic study: lesser-quality randomized controlled trial (eg, <80% follow-up, no blinding, or improper randomization)].

Increasing stability by pre-bending the nails in elastic stable intramedullary nailing: a biomechanical analysis of a synthetic femoral spiral fracture model

Elastic stable intramedullary nailing (ESIN) is generally acknowledged to be the treatment of choice for displaced diaphyseal femoral fractures in children over the age of three years, although complication rates of up to 50% are described. Pre-bending the nails is recommended, but there are no published data to support this. Using synthetic bones and a standardised simulated fracture, we performed biomechanical testing to determine the influence on the stability of the fracture of pre-bending the nails before implantation. Standard ESIN was performed on 24 synthetic femoral models with a spiral fracture. In eight cases the nails were inserted without any pre-bending, in a further eight cases they were pre-bent to 30° and in the last group of eight cases they were pre-bent to 60°. Mechanical testing revealed that pre-bending to 60° produced a significant increase in the stiffness or stability of the fracture. Pre-bending to 60° showed a significant positive influence on the stiffness compared with unbent nails. Pre-bending to 30° improved stiffness only slightly. These findings validate the recommendations for pre-bending, but the degree of pre-bend should exceed 30°. Adopting higher degrees of pre-bending should improve stability in spiral fractures and reduce the complications of varus deformity and shortening.

EPIDEMIOLOGICAL STUDY OF CHILDREN DIAPHYSEAL FEMORAL FRACTURES

OBJECTIVE

To evaluate the personal, fracture, treatment and complication characteristics among patients with pediatric femoral shaft fractures attended at the pediatric orthopedic service of the Joana de Gusmão Children's Hospital.

METHODS

This was a retrospective cross-sectional study on a population consisting of patients with femoral shaft fractures, aged between birth and 14 years and 11 months, who were divided into four age groups. Information was obtained from medical records and was transferred to a survey questionnaire to present personal, fracture, treatment and complication variables.

RESULTS

The study population consisted of 96 patients. Their mean age was 6.8 years. The cases were predominantly among males, comprising closed fractures on the right side, in the middle third with a single line. Regarding fracture etiology, traffic accidents predominated overall in the sample. Most of the patients (74 to 77.1%) presented femoral fractures as their only injury. Conservative treatment predominated in the group younger than six years of age, and surgical treatment in the group aged 6 to 14 years and 11 months. The complications observed until bone union were: discrepancy, infection and movement limitation. The mean time taken for consolidation was 9.6 ± 2.4 weeks, varying with age.

CONCLUSION

The features of these fractures were similar to those described in the literature and the treatment used showed good results. The Joana de Gusmão Children's Hospital has used the treatment proposed in the literature for pediatric femoral shaft fractures.

A comparison of locked versus nonlocked Enders rods for length unstable pediatric femoral shaft fractures

BACKGROUND

Stainless steel flexible Enders rods have been used for intramedullary fixation of pediatric femur fractures with good success. Despite intraoperative anatomic alignment, length unstable femur fractures can present postoperatively with fracture shortening. The purpose of this study was to review all length unstable pediatric femoral shaft fractures in which Enders rods were used and compare those that were locked to those that were not locked.

METHODS

A retrospective clinical and radiographic review of all patients at a single institution undergoing flexible intramedullary fixation for length unstable femoral shaft fractures from 2001 to 2008. A length unstable fracture was defined as either a comminuted fracture or a spiral fracture longer than twice the diameter of the femoral shaft. A total of 107 length unstable femoral shaft fractures fixed with Enders rods were identified, of which 37 cases (35%) had both Enders rods "locked" through the eyelet in the distal femur with a 2.7 mm fully threaded cortical screw. Patient demographics, clinical course, complications, fracture characteristics, and radiographic outcomes were compared for the locked and nonlocked groups.

RESULTS

There were no statistical differences between the groups in demographic data, operative variables, fracture pattern, fracture location, time to union, femoral alignment, or major complications. Shortening of the femur and nail migration measured at 1 to 6 weeks postoperatively was significantly greater for the nonlocked cases. The medial and lateral locked Enders rods moved 1.3 and 1.9 mm, respectively, and the unlocked Enders each moved 12.1 mm (P < 0.05). At final follow-up there were significantly more (P < 0.05) clinical complaints in nonlocked group, including limp, clinical shortening, and painful palpable rods.

CONCLUSIONS

Locking Enders rods for length unstable pediatric fractures is an excellent option to prevent shortening and resulted in no additional complications, added surgical time, or increased blood loss.

LEVEL OF EVIDENCE

Level III.

Biomechanical analysis of a synthetic femoral spiral fracture model: Do end caps improve retrograde flexible intramedullary nail fixation?

Background

Elastic Stable intramedullary Nailing (ESIN) of dislocated diaphyseal femur fractures has become an accepted method for the treatment in children and adolescents with open physis. Studies focused on complications of this technique showed problems regarding stability, usually in complex fracture types such as spiral fractures and in older children weighing > 40 kg. Biomechanical in vitro testing was performed to evaluate the stability of simulated spiral femoral fractures after retrograde flexible titanium intramedullary nail fixation with and without End caps.

Methods

Eight synthetic adolescent-size femoral bone models (Sawbones^® with a medullar canal of 10 mm and a spiral fracture of 100 mm length identically sawn by the manufacturer) were used for each group. Both groups underwent retrograde fixation with two 3.5 mm Titanium C-shaped nails inserted from medial and lateral entry portals. In the End Cap group the ends of the nails of the eight specimens were covered with End Caps (Synthes Company, Oberdorf, Switzerland) at the distal entry.

Results

Beside posterior-anterior stress (4.11 Nm/mm vs. 1.78 Nm/mm, p < 0.001), the use of End Caps demonstrated no higher stability in 4-point bending compared to the group without End Caps (anterior-posterior bending 0.27 Nm/mm vs. 0.77 Nm/mm, p < 0.001; medial-lateral bending 0.8 Nm/mm vs. 1.10 Nm/mm, p < 0.01; lateral-medial bending 0.53 Nm/mm vs. 0.86 Nm/mm, p < 0.001) as well as during internal rotation (0.11 Nm/° vs. 0.14 Nm/°, p < 0.05). During compression in 9°- position and external rotation there was no statistical significant difference (0.37 Nm/° vs. 0.32 Nm/°, p = 0.13 and 1.29 mm vs. 2.18 mm, p = 0.20, respectively) compared to the "classic" 2-C-shaped osteosynthesis without End Caps.

Conclusion

In this biomechanical study the use of End Caps did not improve the stability of the intramedullary flexible nail osteosynthesis.

Treatment of femur fractures in school-aged children using elastic stable intramedullary nailing: a systematic review

Femur fractures are common long-bone injuries in school-aged children (6-12 years). Among the various acceptable treatment options, elastic stable intramedullary nailing (ESIN) has gained popularity over recent years although the level of evidence for ESIN is low. This study was a systematic review of the literature to examine the outcomes and complications of ESIN in school-aged children and to critically evaluate the quality of the available literature. Although most complications were minor, some series report complication rates of more than 50%. Union rates are high. Malunion or mechanical axis malalignment, on the other hand, is common, and leg length discrepancy and overgrowth are also not unusual. Symptomatic implants are common, particularly if the distal ends of the nail are left long and prominent. Refracture was noted to be uncommon in this population. ESIN is a well-accepted and reliable option for treatment of femur fractures in school-aged children. Advantages are decreased length of hospital stay, early return to function, and high union rates. Care must be taken to obtain and maintain reduction, and caution is advised in older and heavier children.

Biomechanical analysis of a synthetic femur spiral fracture model: Influence of different materials on the stiffness in flexible intramedullary nailing

BACKGROUND

Flexible intramedullary nail fixation of dislocated diaphyseal femur fractures has gained wide acceptance for children and adolescents with open physes. Studies with a special emphasis on complications reveal frequent problems regarding stability, usually in complex fracture types such as spiral fractures and in older children weighing >40kg. This biomechanical study analyses how much the material of the nails influences the stiffness in a synthetic bone model.

METHODS

Twenty-four composite grafts (Sawbones®, 4th generation, medullar canal of 10mm) with an identical spiral fracture were used in three configurations of eight grafts. Elastic stable intramedullary nailing was performed in a retrograde C-shaped manner with two nails of equal size (2×3.5mm). Close contact of the fragments could be achieved. We compared Group A (steel nails) with Group B and C (two types of titanium nails). All specimens underwent 4-point bending, torsion and axial compression in the 0° and 9° positions, and the results were analysed.

FINDINGS

Group A (steel nails) revealed a significantly higher stiffness in all directions than Group B. Apart from compression in the 9° position this steel nail fixation showed significant higher stiffness than titanium nails of Group C. Comparing Group B and C did not show an systematic difference.

INTERPRETATION

In this biomechanical study with composite artificial bones the use of steel Nails demonstrated the highest stiffness in our model when compared to two different titanium nail configurations. Apart from in cases of known allergy or planned MRI-examinations our results and data from the literature question the use of titanium nails.

Limb geometry after elastic stable nailing for pediatric femoral fractures

BACKGROUND

Elastic stable intramedullary nailing has become a popular treatment for pediatric long-bone fractures. However, early limb malalignment and length differences may occur in children with femoral fractures who are managed with this procedure.

METHODS

We prospectively followed sixty-eight children (mean age, 5.6 years) who were managed with elastic stable intramedullary nailing for the treatment of a unilateral femoral shaft fracture in order to evaluate early angular or rotational malalignment or limb-length discrepancy. The average body weight was 21 kg (range, 10 to 45 kg). There were fifty-seven AO/ASIF Type-A fractures and eleven Type-B fractures. Malalignment was assessed with use of radiographs, computed tomography, or navigated ultrasound examination after four to seven months to evaluate the short-term result of fixation and to eliminate changes caused by later bone remodeling.

RESULTS

The mean femoral length difference was 0.5 mm of femoral lengthening. Only eleven patients (16%) had a limb-length discrepancy of >10 mm. Mechanical axial deviation of >5 degrees occurred in one patient. However, the mean femoral rotational angle difference was 14.5 degrees . Thirty-two children (47%) had > or =15 degrees of torsional malalignment.

CONCLUSIONS

Elastic stable intramedullary nailing can provide satisfactory results in terms of limb length and axial alignment, but a high rate of early torsional malalignment may be seen.

Femoral nailing to treat fractures after lengthening for congenital femoral deficiency in young children

Congenital femoral deficiency in children can be treated with femoral lengthening. A common complication is fracture soon after removal of the external fixator, often despite prophylactic hip spica cast application. These fractures present special challenges because the patients have tight soft tissues and sclerotic intramedullary canals. We treated nine such fractures in eight children (average age, 5.4 years). Most were 'spontaneous' events resulting in transverse fracture through regenerate bone or pin sites. All were stabilized with intramedullary Rush pins using special insertion techniques. Union was achieved (average, 6 weeks); no significant complications occurred. We describe details of the surgical technique.

Surgical treatment of femoral fractures in childrenComparison between external fixation and elastic intramedullary nails: A review

Femoral fractures represent about 2% of all fractures in childhood. Children with femoral fractures always need to be admitted to hospital and the use of resources is much higher than for other childhood fractures. During the past decade, there has been a trend towards surgical treatment of these fractures, one advantage being the shorter time required in hospital. Two common surgical treatment options are external fixation (EF) and elastic stable intramedullary nails (ESIN). Both methods have their advantages and disadvantages, and neither of them solves all of the problems. Used in a complementary manner, they are safe and reliable for the treatment of femoral fractures in children, and they give good long-term results and few serious complications.

Antegrade intramedullary nailing of pediatric femoral fractures using an interlocking pediatric femoral nail and a lateral trochanteric entry point

BACKGROUND

The treatment of femoral shaft fractures in older children and adolescents using rigid intramedullary (IM) nail fixation offers the advantages of decreased soft tissue stripping, low incidence of malalignment, leg length discrepancy, early ambulation, and decreased hospital stay. Recent reports have described the development of osteonecrosis of the femoral head in children after IM nailing through the piriformis fossa and the tip of the greater trochanter. Others have noted secondary proximal femoral valgus and femoral neck narrowing after antegrade IM nailing. Using the lateral aspect of the greater \trochanter as the starting point avoids the tenuous blood supply of the proximal femur and did not seem to produce avascular necrosis or proximal femoral deformity in early reports.

METHODS

A retrospective clinical and radiographic review of 78 children and adolescents with 80 femoral shaft fractures who underwent IM nail fixation through the lateral aspect of the greater trochanter, with a mean follow-up of 99 weeks, was performed. Twenty-four fractures were observed until skeletal maturity. Final standing anteroposterior radiographs of both lower extremities were used to assess for evidence of osteonecrosis, limb length discrepancy, fracture alignment, and indices around the hips.

RESULTS

All patients went on to union in good clinical alignment without loss of reduction. No nonunions, delayed unions, or malunions were observed. Two patients developed infections postoperatively (2.5%). No patient had evidence of osteonecrosis of the femoral head. There was no significant difference in neck-shaft angle, articulotrochanteric distance, or femoral diameter when compared with the nonsurgical, normal side in these patients.

CONCLUSIONS

Intramedullary nail fixation through the lateral aspect of the greater trochanter in children and adolescents is effective. It does not produce clinically important femoral neck valgus or narrowing. We did not observe osteonecrosis of the femoral head.

LEVEL OF EVIDENCE

: Level IV, case series.

Flexible interlocked nailing of pediatric femoral fractures: experience with a new flexible interlocking intramedullary nail compared with other fixation procedures

BACKGROUND

The optimal treatment of femoral shaft fractures in older children and adolescents remains controversial. We hypothesized that fixation with a flexible interlocking intramedullary nail (FIIN) reduces perioperative complications and improves outcomes, including leg-length discrepancy, time to healing, and time to weight bearing compared with other fixation procedures (OFPs) including standard elastic nail implants.

METHODS

Using a retrospective cohort study design, we reviewed medical records and radiographs of children, 7 to 18 years of age, with femoral shaft fractures requiring open treatment between July 1, 1998, and June 30, 2003. Patients selected for the study had unilateral fracture sites proximal to the supracondylar region and distal to the lesser trochanter, presence of open femoral growth plates, and open surgical treatment. Analyses compared inpatient measures and patient outcomes between FIIN and OFP groups.

RESULTS

Of the 160 patients eligible for inclusion, 23 were lost to follow-up. The remaining 137 patients had a mean follow-up of 396.3 days (SD, 320.4 days), with 58 receiving FIIN fixation and 79 OFP. Although the difference was not statistically significant, complications occurred in 19.0% of patients in the FIIN group and 30.4% in the OFP group. Trochanteric heterotopic ossification was the most common complication (13.8%) noted in the FIIN group and superficial infection (12.8%) in the OFP group. The FIIN group experienced less blood loss (P = 0.042) and shorter time to weight bearing (P = 0.001) without disturbance of proximal femoral geometry or avascular necrosis of the femoral head. In children weighing less than 45.5 kg (100 lb), complications were less common with FIIN (3.6%) compared with OFP (24.4%). A subgroup of patients less than 45.5 kg (100 lb) with standard elastic nail implants (n = 24) had 8.1 times the complications of patients with FIIN.

CONCLUSIONS

Older children and adolescents with femoral shaft fractures treated with a FIIN showed improved outcomes compared with patients treated with OFP.

LEVEL OF EVIDENCE

Level III, therapeutic study.

A computational evaluation of the effect of intramedullary nail material properties on the stabilization of simulated femoral shaft fractures

Titanium flexible intramedullary nails have become far more prevalent for stabilization of pediatric femur fractures in recent years. While steel may be expected to have superior fracture stability due to its higher elastic modulus; titanium alloy has experimentally demonstrated improved biomechanical stability, as measured by gap closure and nail slippage. The purpose of this study was to verify these observations computationally, and thus, explain why titanium alloy may be better suited for surgical fixation of fractured femurs. A finite element model of a femur with complete mid-diaphyseal fracture and having two 3.5 mm nails in a retrograde "C" pattern was created. Static analyses were run in which the nail material properties were titanium alloy or stainless steel, respectively. Gap closure for the stainless steel nails was 1.03 mm; while the titanium alloy nails had 0.69 mm of closure. Titanium alloy nails slipped slightly less at each loading increment than stainless steel nails. The titanium alloy nails distributed stress more evenly along the nail axis, resulting in lower peak magnitudes. These results agree with previously published clinical and biomechanical studies that reported increased gap closure and nail slippage with stainless steel nails. The increased deformation of the titanium alloy nail likely increases the contact area with the intramedullary canal wall, thus, increasing stability. Additionally, stainless steel nails had higher curve apex von Mises stresses, potentially inducing a stress-shielding effect which could hamper remodeling and consequently increase risk of re-fracture.

Complications after titanium elastic nailing of pediatric tibial fractures

A retrospective review of 60 diaphyseal tibia fractures (31 closed and 29 open fractures) treated with flexible intramedullary fixation was conducted. All charts and radiographs were reviewed. Children ranged in age from 5.1 to 17 years. Fifty patients with 51 fractures were followed up until union and comprised the study group. The mean follow-up period for these 50 patients was 79 weeks. Forty-five fractures achieved bony union within 18 weeks (mean, 8 weeks). Five patients (11%) had delayed healing (3 had delayed unions that ultimately healed with casting or observation, and 2 had nonunions that required secondary procedures to achieve union [1 patient underwent a fibular osteotomy, and 1 underwent exchange nailing with a reamed tibial nail]). These 5 fractures ultimately healed, with a mean time to union of 41 weeks. Patients with delayed healing tended to be older (mean age, 14.1 years) versus the study population as a whole (mean age, 11.7 years). In addition to delayed union, other complications were observed in the study population. One patient healed with malunion (13-degree valgus), requiring corrective osteotomy. One patient with a grade II open fracture was diagnosed with osteomyelitis at the fracture site after attaining bony union. Two patients developed nail migration through the skin, requiring modification or nail removal. The fixation of pediatric diaphyseal tibia fractures with titanium elastic nails is effective but has a substantial rate of delayed healing, particularly in older patients.

Stainless steel flexible intramedullary fixation of unstable femoral shaft fractures in children

To assess the role of stainless steel flexible intramedullary fixation in unstable pediatric femur fractures, we compared a group of 41 stable (transverse or oblique) fractures with a group of 40 unstable (spiral and/or comminuted) fractures treated with stainless steel (Ender) nails placed through a single lateral insertion. The fractures were followed up until clinical and radiographic union was evident with an average follow-up period of 13 months. All fractures were healed at an average of 1.4 months. No infections or refractures occurred. Although minor radiographic angular deformities and shortening were present in both groups, no patient had a clinically detectable angular deformity. Two patients with stable fracture patterns had 10 to 20 degrees of asymmetry in foot progression angles, and 1 patient with an unstable fracture pattern (Winquist grade IV comminution) had a 3-cm limb length difference at final follow-up. Stainless steel flexible intramedullary fixation is effective for unstable pediatric femur fractures if cortical abutment is present.

Fraturas diafisárias de fêmur em crianças e adolescentes

Foram avaliados 71 pacientes com idade abaixo de 16 anos, portadores de 72 fraturas diafisárias do fêmur, ocorridas de 01/1995 a 12/1998. Os objetivos do estudo foram conhecer aspectos descritivos dessas fraturas e avaliar o tratamento empregado. A idade foi o principal critério para escolha do tratamento, sendo aqueles abaixo de 3 anos (Grupo I) tratados com gesso imediato, os de 3 a 10 anos (Grupo II) com gesso após tração e os acima de 11 anos (Grupo III) de modo conservador ou cirúrgico. A média de idade foi 6,3±3,8 anos, havendo predomínio do gênero masculino e de fraturas fechadas. Acidente de trânsito foi o mecanismo de lesão mais comum. A fratura localizou-se no terço médio, em 60,6% dos casos, no proximal em 23,9% e no distal em 15,5%. Noventa e três porcento eram fraturas de traço simples, 4,2% cominutivas e 2,8% segmentares. Lesões associadas foram identificadas em 35,2% dos pacientes. Todas fraturas nos Grupos I e II e 60% daquelas no Grupo III foram tratadas conservadoramente. As complicações observadas até a união óssea foram: discrepância, infecção no trajeto do fio, consolidação viciosa e limitação de movimento do joelho. O tempo médio de consolidação foi 8,6±3,4 semanas, variando com a idade. Concluiu-se que as características das fraturas estudadas foram semelhantes às citadas na literatura e que o tratamento empregado apresentou bom resultado.

Flexible intramedullary nailing in pediatric lower limb fractures

Seventy-three children (48 boys and 25 girls; mean age, 5.7 years) with unilateral femoral or tibial shaft fractures were treated using elastic intramedullary nails at the authors' institution. There were 61 simple type A fractures (84%) and 12 wedge type B fractures (16%). All but 3 children had closed fractures. Associated injuries were seen in one third of the cases. All fractures were reduced by closed manipulation. Union was achieved in all cases without additional intervention. Technical problems occurred in few patients. Improper nail length was seen in 4 cases. None of the study patients developed deep infection. No angulation greater than 15 degrees was found after femoral fractures. Nine patients had length discrepancy greater than 10 mm. Spiral fractures showed a tendency for shortening whereas transverse fractures were more associated with post-traumatic lengthening. No significant axial malalignment or shortening was seen in tibial fractures. Torsional differences of greater than 15 degrees were detected by computed tomography or navigated ultrasound examination in nearly half of the patients; however, only 4 children had clinically apparent gait changes. The study confirms the satisfactory results of treating pediatric lower limb fractures using elastic nails. Proper surgical technique and intraoperative control of limb alignment can help avoid postoperative deformities.

Complications of pediatric femur fractures treated with titanium elastic nails: a comparison of fracture types

The purpose of this study was to analyze complications seen in children with femur fractures stabilized with titanium elastic nails, comparing their use in stable and unstable fracture patterns. A retrospective review was performed on 39 consecutive children with femur fractures treated with titanium elastic nails. Patients with comminuted or long oblique fractures were classified as having "length-unstable" fractures. Patients were analyzed qualitatively for any predictive factors or treatment variables that increased the risk of complications. There were 24 patients with complications (62%). Eight patients (21%) underwent unplanned surgery prior to complete fracture union. Six of the eight requiring unplanned surgery were treated for "length-unstable" fractures. The complications that required unplanned surgery for either prominent nails or loss of reduction occurred more commonly in unstable non-transverse fracture patterns. The authors conclude that in patients with "length-unstable" femur fractures, consideration should be given to methods of treatment other than titanium flexible intramedullary nails.

The locked flexible intramedullary humerus nail in pediatric femur and tibia shaft fractures: a feasibility study

There are several options for the treatment of long bone fractures in skeletally immature patients. Surgeon experience, type of fracture, and the possibility of damage to the physeal area dictate individual fracture management patterns. Notably, nail devices have not gained popularity in this patient group. Intramedullary locking nails have become the standard of care in adult patients due to decreased morbidity and mortality. A novel nail has been developed for humeral shaft fractures that uses a lateral starting position to avoid damage to the rotator cuff in humeral fracture fixation. This is possible because of the nail's transient flexibility during insertion. This study illustrates that it is feasible to insert this type of nail through multiple entry portals for both tibial and femoral fracture fixation, without damaging the physeal blood supply or growth areas.

[Experience with elastic stable intramedullary nailing (ESIN) of shaft fractures in children]

The aim of this prospective clinical controlled trial was to investigate the early and midterm results of shaft fractures in children treated with elastic stable intramedullary nailing (ESIN). From January 1997 to December 2001, elastic stable intramedullary nailing was carried out on 112 children with 118 diaphyseal fractures. The mean age was 7.7 years. There were 51 fractures of the lower arm, 46 femoral fractures, 14 of the lower leg, and 7 of the humerus. A total of 92 children have been followed up for more than 12 months. The mean time of follow-up was 38 months.The mean time of fluoroscopy was 2.2 min. Open reduction was necessary in 3.4 %. In children with injuries of the lower extremity, full weight bearing was achieved after a mean period of 9.3 days. In 1.8% of the children, reoperation was necessary within the first 10 days after the operation. In 3.6 % there was painful skin irritation due to the protruding end of a nail. No infection or delayed union was observed. Implant removal was done after a mean time of 5.6 months. There was no rotational or angular deformity of more than 5 degrees in children with isolated fractures of the lower extremity. Mean lengthening of the injured leg was 2.4 mm. In three children who had fractures of the upper extremity, a deficit in range of motion of the adjacent joints was detected. The current results show that intramedullary fixation of displaced diaphyseal fractures in children with a flexible titanium nail is a safe, minimally invasive surgical technique producing excellent functional and cosmetic results.

Tibial lengthening over nails in children using modified Ender nails: preliminary results of a new treatment

Tibial lengthening over nails, using modified Ender nails, was performed in nine children whose mean age at surgery was 12.8 years. The prerequisite for using this technique was the absence of axial malalignment and an indication for tibial lengthening only. Lengthening was not performed in one case due to the development of a compartment syndrome after the tibial osteotomy. Breakage of one interlocking screw without loss of alignment or length was observed in one case. Superficial pin tract infections were observed in two cases. An average of 4.1 cm (range 3-4.5 cm) lengthening of the tibia was achieved in eight of the nine cases. The modified Ender nails used permitted locking at both ends after achieving the desired distraction and permitted early removal of the external fixator. The advantage of this technique is that it permits early removal of the fixator and thus decreases the incidence of fixator related problems and facilitates early rehabilitation.

Pitfalls und Komplikationen der elastisch stabilen intramedull�ren Nagelung (ESIN) von Femurfrakturen im Kindesalter

BACKGROUND

The aim of this prospective study was to evaluate the intra- and postoperative problems as well as the complications of elastic stable intramedullary nailing (ESIN) of femur fractures in children.

PATIENTS AND METHODS

47 consecutive children, mean age 6 years, were reviewed clinically and radiologically until hardware removal and after this annually. Mean time of follow up was 37 months.

RESULTS

Intraoperatively one cortex perforation and one displacement of a third fragment occurred. Two correction operations were necessary: In one case due to an implant displacement and in another case due to an unacceptable loss of reduction. There were no infections, non union, implant breakage, refracture or disturbance of growth.

CONCLUSIONS

ESIN is a safe procedure in femoral shaft fractures of children. Most of the problems and complications can be avoided by a careful consideration of the indication and a correct operation technique.

Intramedullary nailing of femoral fractures in children through the lateral aspect of the greater trochanter using a modified rigid humeral intramedullary nail: preliminary results of a new technique in 15 children

OBJECTIVES

To evaluate the clinical results of intramedullary nailing of femoral shaft fractures using a rigid intramedullary nail placed through the lateral aspect of the greater trochanter in older children and adolescents.

DESIGN

A retrospective study was carried out evaluating all skeletally immature patients with femoral shaft fractures treated using a modified rigid humeral intramedullary nail.

PATIENTS/PARTICIPANTS

Fifteen children and adolescents with displaced femoral diaphyseal fractures and open physes.

INTERVENTION

Femoral shaft fractures in children and adolescents were stabilized using a modified humeral intramedullary nail placed through the lateral aspect of the greater trochanter.

MAIN OUTCOME MEASUREMENTS

Patients were evaluated to determine time to union, final fracture alignment, hospital stay, complications, clinical outcome, and proximal femoral changes including avascular necrosis or proximal femoral valgus with femoral neck narrowing.

RESULTS

Fifteen patients were followed for a minimum of 1 year (range 70-157 weeks). The average age of the patients was 12 years and 5 months (range 8 years and 2 months-17 years and 1 month). All fractures healed at a mean of 7 weeks (range 5-14 weeks) after fracture. The average hospital stay for patients with isolated femur fractures (8/15) was 2.8 days (range 1-5 days). At an average follow-up of 141 weeks (range 70-326 weeks), no patient had developed avascular necrosis, femoral neck valgus, femoral neck narrowing, or other complications.

CONCLUSIONS

The technique of intramedullary nailing in children through the lateral aspect of the greater trochanter seems to be safe, effective, and well tolerated by patients.

Flexible intramedullary nailing for the treatment of unicameral bone cysts in long bones

BACKGROUND

Unicameral bone cyst is characterized by its tenacity and risk of recurrence. Pathological fracture is common and is often the presenting symptom. The objective of the present study was to evaluate the results of flexible intramedullary nailing for the treatment of a unicameral bone cyst with or without a pathological fracture.

METHODS

Flexible intramedullary nailing for the treatment of a unicameral bone cyst was performed in thirty-two patients. Thirty of these patients presented with a pathological fracture; twenty-four were managed immediately with intramedullary nailing, and the other six had been managed conservatively at other clinics before they were referred to our department. The remaining two cysts were detected incidentally. The cyst was located in the humerus in twenty-one patients, in the femur in nine, and in the radius in two. The mean age of the patients at the time of surgery was 9.8 years, and the mean duration of follow-up was 53.7 months. Radiographic evaluation was performed according to the criteria of Capanna et al., and the cyst was classified as completely healed, healed with residual radiolucency (osteolysis), recurred, or having no response.

RESULTS

The healing period ranged from three to 105 months. Fourteen cysts healed completely, and sixteen healed with residual radiolucent areas visible on radiographs. There was recurrence of two cysts that had healed with residual radiolucency. All of the cysts in the present study responded to treatment. A change of nails was necessary in nine patients, as the nails had become too short after bone growth. No major complications were observed.

CONCLUSIONS

Flexible intramedullary nailing provides early stability, which allows early mobilization and thus obviates the need for a plaster cast and decreases the prevalence of the most common complication: a pathological fracture. This method of treatment also allows for an early return to normal activity.