Paediatric forearm refractures with retained plates managed with flexible intramedullary nails

Subsequent Forearm Fractures Following Initial Surgical Fixation

INTRODUCTION

Forearm fractures are a common pediatric injury. Currently, there is no consensus on treatment for fractures that recur following initial surgical fixation. The objective of this study was to investigate the subsequent fracture rate and patterns and describe the treatment of these forearm fractures.

METHODS

We retrospectively identified patients who underwent surgical treatment for an initial forearm fracture at our institution between 2011 and 2019. Patients were included if they sustained a diaphyseal or metadiaphyseal forearm fracture that was initially treated surgically with a plate and screw construct (plate) or elastic stable intramedullary nail (ESIN), and if they subsequently sustained another fracture that was treated at our institution.

RESULTS

A total of 349 forearm fractures were treated surgically with ESIN or a plate fixation. Of these, 24 sustained another fracture, yielding a subsequent fracture rate of 10.9% for the plate cohort and 5.1% for the ESIN cohort ( P =0.056). The majority of plate refractures (90%) occurred at the proximal or distal plate edge, while 79% of the fractures treated previously with ESINs occurred at the initial fracture site ( P <0.001). Ninety percent of plate refractures required revision surgery, with 50% underwent plate removal and conversion to ESIN, and 40% underwent revision plating. Within the ESIN cohort, 64% were treated nonsurgically, 21% underwent revision ESINs, and 14% underwent revision plating. Tourniquet time for revision surgeries were shorter for the ESIN cohort (46 vs. 92 min; P =0.012). In both cohorts, all revision surgeries had no complications and healed with evidence of radiographic union. However, 9 patients (37.5%) underwent implant removal (3 plates and 6 ESINs) after subsequent fracture healing.

CONCLUSIONS

This is the first study to characterize subsequent forearm fractures following both ESIN and plate fixation and to describe and compare treatment options. Consistent with the literature, refractures following surgical fixation of pediatric forearm fractures may occur at a rate ranging from 5% to 11%. ESINs are both less invasive at the time of initial surgery and can often be treated nonoperatively if there is a subsequent fracture, while plate refractures are more likely to be treated with a second surgery and have a longer average surgery time.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Impact Response and Simulation of Damaged Ulna With Internal Fixation

The objectives of this work were to explore a methodology that combines static and dynamic finite element (FE) analysis, linear elastic fracture mechanics (LEFM) and experimental methods to investigate a worst-case scenario in which a previously damaged bone plate system is subjected to an impact load. Cadaver ulnas with and without midshaft dynamic compression plates are subjected to a static three-point bend test and loaded such that subcritical crack growth occurs as predicted by a hybrid method that couples LEFM and static FE. The plated and unplated bones are then unloaded and subsequently subjected to a midshaft transverse impact test. A dynamic strain-based FE model is also developed to model the midshaft transverse impact test. The average value of the impact energy required for failure was observed to be 10.53% greater for the plated set. There appears to be a trade-off between impact damage and impact resistance when ulnas are supported by fixation devices. Predictions from the dynamic FE model are shown to corroborate inferences from the experimental approach.

Anatomical landmarks in the paediatric distal radius: a new method for measuring epiphyseal height

PURPOSE

Elastic stable intramedullary nailing for fixation of paediatric forearm fractures has become the preferred method of osteosynthesis. The aim of the study was to develop a method for finding the correct entry point in the distal radius of children of all ages as a distance from the radial styloid, a landmark which is readily palpable at the wrist.

METHOD

MRI scans of the wrist in 19 children aged 2-7 years (mean 5) were reviewed. We noted that the proximal edges of the ossific nucleus of capitate and the tip of the radial styloid were at the same vertical height from the physis. This allowed us to review 519 wrist radiographs of children aged 2-14 years (mean 7.98) to measure the epiphyseal height, as the radial styloid does not ossify until the age of 14 years.

RESULTS

The epiphyseal height had a mean of 16.67 mm (13-21 mm). The epiphyseal height in boys was greater than the girls by a mean of 1.2 mm (p < 0.0005).

CONCLUSION

For the absolute safe distance, we recommend an insertion site 40 mm proximal to the tip of the radial styloid, which is safe in all children with an open distal radial physis. This simple and reproducible method allows the identification of the insertion site for the nail with only the minimal use of imaging.

Paediatric diaphyseal forearm refractures after greenstick fractures: operative management with ESIN

BACKGROUND

One of the complications of forearm shaft fracture is refracture. Elastic stable intramedullary nailing represents an alternative method for refracture treatment to cast immobilisation for another five to seven weeks. Operative treatment often necessitates an open reduction in most cases due to blocked or narrowed medullary canals. The purpose of this study was to examine the expense of the operative procedure, technique (closed or open intramedullary nailing) and postoperative complications in diaphyseal forearm refractures.

METHODS

We retrospectively examined the expense of operative procedure in 21 children with diaphyseal forearm refractures treated with ESIN.

RESULTS

In 18 cases, closed reduction with nailing was possible; three required an open reduction. In nine patients a closed medullary cavity was present; only two of them needed an open reduction. None of the patients had complications (wound healing, osteomyelitis, rupture of the extensor pollicus longus). Swelling appeared in four patients, paraesthesia of the thumb in one. Free functional movement was achieved in all children. Long term results: No re-refracture occurred. One patient suffered from meteorosensitivity. Twelve are able to do the same sporting activities as before injury.

CONCLUSION

ESIN seems to be one choice for treatment in refracture of the forearm, as in most cases the operative reduction can be performed in a closed way by means of "tricks and hints".