Clinical evaluation of end caps in elastic stable intramedullary nailing of femoral and tibial shaft fractures in children

Factors which can influence elastic stable intramedullary nailing removal in healed bone cysts in children

Elastic stable intramedullary nailing (ESIN) internal fixation is used clinically to treat pathological fractures of bone cysts in children. However, one of the most important complications was removal difficulty. In this study, we aim to analyse the factors which can influence ESIN removal in healed bone cysts in children. From April 2014 to November 2020, the clinical data of 49 children who underwent elastic stable intramedullary nail removal for pathological fractures of the bone cysts in our hospital were retrospectively analysed. The following data, including age, sex, pathological fracture site, with bone graft, number of ESINs, ESIN indwelling time, and extraosseous length of ESIN were collected, and univariate analysis and logistic regression analysis was performed. The frequency of difficulty in ESIN extraction was 44.90% (22/49). The univariate logistic regression analysis showed that age,ESIN indwelling time,with bone garft and extraosseous length of ESIN may be correlated with the difficulty in removing ESIN (P < 0.05), while sex, pathological fracture site, number of ESIN may not be correlated with the difficulty in removing ESIN (P > 0.05).The multivariate logistic regression analysis showed that the ESIN indwelling time was the independent influencing factor for difficulty in removing ESIN (P < 0.05). The factors influencing the ESIN removal in healed bone cysts in children include over 11.79 years old, the long indwelling time of the ESIN(over 10.5 months),with bone graft and short extraosseous length of ESIN(≤ 0.405 cm). These factors influencing ESIN removal in healed bone cysts in children should be considered.

Paediatric femoral shaft fractures: an instructional review for the FRCS examination

This review presents the principal features of paediatric femoral shaft fractures including the contemporary management strategies and relevant supporting evidence. The article is an overview of information relevant to clinical practice, in addition to preparation for the FRCS (Orth) examination.

The use of flexible nails in the treatment of paediatric long bone fractures: Experience at a level one paediatric trauma centre, a cohort study

Introduction

Fractures occur in children at an incidence only surpassed by women >85 years and account for 25 % of paediatric injuries. Over the last three decades, there has been a trend towards operative management of children's fractures including utilisation of flexible nails as popularised by the Nancy group in the 1980s. Between 5 and 11 % of paediatric forearm fractures are now fixed in this manner with complication rates of 12-42 %. This study shares the experience of a paediatric level one major trauma centre using this technique in managing long bone fractures in children.

Methods and materials

This retrospective cohort study comprises a sequential series of 109 cases (71 children) of upper and lower limb fractures in children (aged 16 years and below) who underwent fracture fixation using flexible intramedullary nails between 1st April 2015 and 31st March 2019. Radiological and clinical outcomes and complications were assessed.

Results

Ninety-three cases (10 in the lower limb, 83 in the upper limb) satisfied the inclusion criteria in 57 children with a mean age of 8.6 years. All cases were successfully reduced intra-operatively and 92 (98.9 %) achieved union. Taking into account all complications in the upper and lower limb, the overall complication rate is 30.1 % (28 cases) with the vast majority (13 cases, 46.4 %) occurring in the upper limb due to prominence of metalwork prompting early removal.

Conclusions

This study has shown flexible intramedullary nailing to perform well with good stabilisation of a wide variety of paediatric long bone fractures with restoration of bone alignment, satisfactory outcomes with good union rates and a return to normal function. The technique is also safe and in the upper limb can be performed as day-case surgery by a generalist orthopaedic surgeon. Although the overall complication rate is not insignificant, major complications are rare.

Implant removal associated complications after ESIN osteosynthesis in pediatric fractures

PURPOSE

ESIN (elastic stable intramedullary nailing) is considered the gold standard for various pediatric fractures. The aim of this study was to analyze the incidence and type of complications during or after TEN (titanium elastic nail) removal.

METHODS

A retrospective data analysis was performed. Metal removal associated complications and preoperative extraosseous length/outlet angle of TENs as possible causes of complications were assessed.

RESULTS

The complication rate in 384 TEN removals was 3.1% (n = 12). One major complication (rupture of M. extensor pollicis brevis) was documented. One refracture at the forearm occurred, however, remodeling prior TEN removal was completed. Ten minor complications were temporary or without irreversible restrictions (3 infections, 5 scaring/granuloma, 2 temporary paraesthesia). In 38 cases (16 forearms, 10 femora, 9 humeri, 3 lower legs), intra-operative fluoroscopy had to be used to locate the implants. In patients with forearm fractures, extraosseous implant length was relatively shorter than in cases without fluoroscopy (p = 0.01), but outlet angle of TENs was not significantly different in these two groups (28.5° vs 25.6°). In patients with femur fractures, extraosseous implant length and outlet angle were tendentially shorter, respectively, lower, but this did not reach statistical significance.

CONCLUSION

Removal of TENs after ESIN is a safe procedure with a low complication rate. Technically inaccurate TEN implantation makes removal more difficult and complicated. To prevent an untimely removal and patient discomfort, nail ends must be exactly positioned and cut. Intraoperative complications may be minimized with removal of TENs before signs of overgrowth.

EVIDENCE

Level III, retrospective.

The clinical features, management options and complications of paediatric femoral fractures

This article discusses the incidence, applied anatomy and classification of paediatric femoral fractures based on critical appraisal of the available evidence. The aim is to identify techniques that are relevant to contemporary practice whilst excluding the technical details of individual procedures that are beyond the scope of this review. Injuries of the proximal, diaphyseal and distal segments are considered individually as there are considerations that are specific to each anatomical site. Femoral neck fractures are rare injuries and require prompt anatomical reduction and stable fixation to minimise the potentially devastating consequences of avascular necrosis. Diaphyseal fractures are relatively common, and there is a spectrum of management options that depend on patient age and size. Distal femoral fractures often involve the physis, which contributes up to 70% of femoral length. Growth arrest is common consequence of fractures in this region, resulting in angular and length-related deformity. Long-term surveillance is recommended to identify deformity in evolution and provide an opportunity for early intervention. Deliberate injury should be considered in all fractures, particularly distal femoral physeal injuries and fractures in the non-walking child.

[Diaphyseal and metaphyseal femoral fractures in childhood]

Femoral fractures in childhood are rare and are usually the result of severe trauma. Conservative treatment (overhead extension, hip spica cast) can be used in children up to 3 years of age and beyond that elastic stable intramedullary nailing (ESIN) is the method of choice. The prognosis is very good if the surgical technique is adequate. In adolescents > 50 kg in body weight solid nails implanted via the greater trochanter are an alternative (adolescent lateral femoral nail, ALFN). External fixators and plate osteosynthesis are indicated in special situations. Femoral neck fractures are very seldom seen in this age group. Besides Kirschner (K)-wires and screw osteosynthesis a special pediatric hip plate is available in this situation. In the distal metaphysis mostly stable fractures occur in disabled children, which can usually be treated conservatively. In addition, pathological fractures occur in juvenile bone cysts and complex injuries in adolescents, which need stabilization by descending ESIN or with plates. At the distal growth plate relevant growth disturbances are possible.

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.

The management of paediatric diaphyseal femoral fractures: a modern approach

The definitive treatment of paediatric femoral diaphyseal fractures remains controversial. Modalities of treatment vary mostly according to age, with fracture pattern and site having a lesser impact. Current evidence is reflective of this variation with most evidence cited by the American Academy of Orthopedic Surgeons being level 4 or 5. The authors present a review of the most up-to-date evidence relating to the treatment of these fractures in each age group. In an attempt to clarify the current trends, we have produced an algorithm for decision-making based on the experience from our own tertiary referral level 1 major trauma centre.

Improving stability of elastic stable intramedullary nailing in a transverse midshaft femur fracture model: biomechanical analysis of using end caps or a third nail

BACKGROUND

Elastic stable intramedullary nailing (ESIN) is accepted widely for treatment of diaphyseal femur fractures in children. However, complication rates of 10 to 50 % are described due to shortening or axial deviation, especially in older or heavier children. Biomechanical in vitro testing was performed to determine whether two modified osteosyntheses with end caps or a third nail could significantly improve the stability in comparison to classical elastic stable intramedullary nailing in a transverse femur fracture model.

METHODS

We performed biomechanical testing in 24 synthetic adolescent femoral bone models (Sawbones®) with a transverse midshaft (diaphyseal) fracture. First, in all models, two nails were inserted in a C-shaped manner (2 × 3.5 mm steel nails, prebent), then eight osteosyntheses were modified by using end caps and another eight by adding a third nail from the antero-lateral (2.5-mm steel, not prebent). Testing was performed in four-point bending, torsion, and shifting under physiological 9° compression.

RESULTS

The third nail from the lateral showed a significant positive influence on the stiffness in all four-point bendings as well as in internal rotation comparing to the classical 2C configuration: mean values were significantly higher anterior-posterior (1.04 vs. 0.52 Nm/mm, p < 0.001), posterior-anterior (0.85 vs. 0.43 Nm/mm, p < 0.001), lateral-medial (1.26 vs. 0.70 Nm/mm, p < 0.001), and medial-lateral (1.16 vs. 0.76 Nm/mm, p < 0.001) and during internal rotation (0.16 vs. 0.11 Nm/°, p < 0.001). The modification with end caps did not improve the stiffness in any direction.

CONCLUSIONS

The configuration with a third nail provided a significantly higher stiffness than the classical 2C configuration as well as the modification with end caps in this biomechanical model. This supports the ongoing transfer of the additional third nail into clinical practice to reduce the axial deviation occurring in clinical practice.

End caps prevent nail migration in elastic stable intramedullary nailing in paediatric femoral fractures: a biomechanical study using synthetic and cadaveric bones

End caps are intended to prevent nail migration (push-out) in elastic stable intramedullary nailing. The aim of this study was to investigate the force at failure with and without end caps, and whether different insertion angles of nails and end caps would alter that force at failure. Simulated oblique fractures of the diaphysis were created in 15 artificial paediatric femurs. Titanium Elastic Nails with end caps were inserted at angles of 45°, 55° and 65° in five specimens for each angle to create three study groups. Biomechanical testing was performed with axial compression until failure. An identical fracture was created in four small adult cadaveric femurs harvested from two donors (both female, aged 81 and 85 years, height 149 cm and 156 cm, respectively). All femurs were tested without and subsequently with end caps inserted at 45°. In the artificial femurs, maximum force was not significantly different between the three groups (p = 0.613). Push-out force was significantly higher in the cadaveric specimens with the use of end caps by an up to sixfold load increase (830 N, standard deviation (SD) 280 vs 150 N, SD 120, respectively; p = 0.007). These results indicate that the nail and end cap insertion angle can be varied within 20° without altering construct stability and that the risk of elastic stable intramedullary nailing push-out can be effectively reduced by the use of end caps.

Femoral fractures in children

PURPOSE OF REVIEW

Femoral fractures in children are the commonest children's fracture requiring hospitalization. They consume disproportionate amounts of healthcare resource. Advances in operative management have resulted in improved clinical and health economic outcomes.

RECENT FINDINGS

This article describes 21st-century management of femoral fractures concentrating on recent advances. There is a clear trend to increased operative management in all femoral fractures with improved outcomes in the proximal femur and shaft. Crucially, advances in the treatment of both have led to a reduction in the rate of avascular necrosis of the femoral head.

SUMMARY

Units treating paediatric fractures need access to specialist surgeons and equipment to treat the full range of femoral fractures and improve outcomes.

Intramedullary nails for pediatric diaphyseal femur fractures in older, heavier children: early results

PURPOSE

A common treatment for pediatric femur fractures is intramedullary nail (IMN) insertion. Elastic stable intramedullary nails (ESINs) are often used for these procedures in heavier patients, but the potential for complications and malunion is greater. We describe here a rigid IMN specifically designed for adolescents, the adolescent lateral entry femoral nail (ALFN). The purpose of this study was to compare the recovery and complications for patients treated with ESINs to those treated with the ALFN.

METHODS

Our study design was a retrospective cohort study. We performed a review of medical records of 22 children ages 10-17 requiring surgical fixation of a femur fracture for a 2½-year period. Patients selected for the study had traumatic diaphyseal femur fractures and were treated with ESINs without end-caps or ALFNs. Our analyses evaluated injury, surgical, and outcome information for all patients.

RESULTS

Twenty-two patients were eligible for inclusion and were divided into two groups according to their treatment: the ESIN group with 7 patients and the ALFN group with 15 patients. We then performed a comparison of complications and recovery for these patients. The mean time to full weight-bearing was significantly less for the ALFN group (4.1 weeks; SD, 2.2), than the ESIN group (9.4 weeks; SD 3.9). There was no statistical difference in the incidence of major or minor complications.

CONCLUSIONS

Older, heavier pediatric patients treated for femur fracture with ALFNs had a shorter recovery time than similar patients treated with ESINs. However, the outcomes for both groups were satisfactory.