Technical considerations for the management of segmental osseous defects with an internal bone transport nail

Clinical compatibility of magnetic resonance imaging with magnetic intramedullary nails: a feasibility study

INTRODUCTION

The use of magnetic resonance imaging (MRI) with a magnetic intramedullary lengthening nail in place is contraindicated per the manufacturer due to the concern of implant activation and migration. A prior in vitro study did not confirm these complications only noting that a 3.0 T MRI weakened the internal magnet. Therefore, a retrospective analysis of patients who underwent an MRI with a magnetic nail in place was performed to determine if any adverse effects occurred in the clinical setting.

MATERIALS AND METHODS

A retrospective review of all patients who underwent an MRI with a magnetic lengthening nail in place was performed. The time spent being imaged in the MRI, number of times the patient entered the MRI suite, and the images obtained were recorded. Radiographs were performed before and after the MRI to determine if any hardware complications occurred. The patients were monitored for any adverse symptoms while they were in the suite.

RESULTS

A total of 12 patients with 13 nails were identified. Two patients underwent imaging with a 3.0 T MRI while the remaining 10 underwent imaging with a 1.5 T MRI. Each patient entered the MRI suite 2.1 times and spent an average of 84.7 min being imaged in the MRI (range 21-494). No patients noted any adverse symptoms related to the nail while in the suite and no hardware complications were identified.

CONCLUSION

MRI appears to be safe with a magnetic nail in place and did not result in any complications. Given the manufacturer's recommendations, informed consent should be obtained prior to an MRI being performed and a 3.0 T MRI should be avoided when possible if further activation of the nail is required.

Management of Segmental Tibial Bone Defects With the Magnetic Motorized Intramedullary Transport Nail: A Case Series

SUMMARY

Critical-sized bone defects in the tibia can arise as sequelae of trauma, infection, tumor, or the treatment of congenital limb deficiencies. Treatment of these defects often requires bone transport, which has traditionally been accomplished using circular external fixators. The development of a bone transport nail facilitated tibia reconstruction through distraction osteogenesis using an all-internal device, thus avoiding the complications associated with chronic external fixation. Given the rarity of these cases, few studies have been published on the reconstruction outcomes using this implant. We sought to investigate the bone healing indices (including regenerate consolidation and time to docking site union) associated with the use of a magnetically controlled all-internal bone transport nail for the reconstruction of 4 patients treated for posttraumatic tibial bone loss. Perioperative and device-related complications are also reported.

[Development and principles of intramedullary and extramedullary segmental bone transport: overview and clinical results]

BACKGROUND

Segmental bone transport using intramedullary or extramedullary techniques is one of the most commonly used procedures for bone defect management in the diaphyseal region of long bones.

OBJECTIVE

The purpose of this work is to provide an overview of the historical development and general principles as well as the current status of extramedullary and intramedullary techniques of bone segment transport. In addition, own results on internal segmental bone transport are presented.

MATERIAL AND METHODS

A retrospective database analysis included all patients between May 2019 and January 2021 who underwent segmental bone transport via a fully implantable intramedullary segment transport nail system. In addition to the radiological outcome, the clinical outcome was assessed using the lower extremity functional scale (LEFS).

RESULTS

A total of 9 patients (8 male, 1 female; age 41.7 ± 3.9 years) could be included. The cause of the segmental bone defect was chronic fracture-related infection in all cases. The segmental defect size was 62 ± 10 mm. Sufficient bridging of the bone defect was achieved in all patients, with a mean distraction rate of 0.9 ± 0.1 mm per day. Bony consolidation of the regeneration was achieved after 292 ± 57 days, and final bony consolidation of the docking zone was achieved after 469 ± 116 days. At 22 ± 3 months after implantation of the segmental transport nail, the LEFS demonstrated a result of 59 ± 4 points. No recurrence of infection or regeneration failure occurred.

CONCLUSION

The aim of treating segmental bone defects, in addition to reconstructing a load-bearing bone, is to restore correct joint angles, leg length, and leg axis without torsional deviation and can be achieved via classical external segmental bone transport. In recent years, internal segmental bone transport has been developed as an alternative. It remains to be seen whether the preliminary and reproducibly good clinical and radiological results of segmental transport nails can be confirmed for widespread use in the future.

Use of the PRECICE Nail for distraction osteogenesis after tumor resection

INTRODUCTION

Reconstructing long bone defects following intercalary tumor resection presents an exciting challenge with a greater range of surgical solutions than more typical situations requiring arthroplasty. Segmental bone transport (distraction osteogenesis) is the least utilized option for intercalary reconstruction, however, it arguably provides patients with the most desirable result. Distraction osteogenesis can be used in the management of multiple skeletal conditions including deformity (either congenital or acquired), or in the presence of bone defects (by trauma or planned surgical excision). Lack of broader adoption of transport is likely due to the highly technical demands and common complications of utilizing fine-wire fixators via the Ilizarov method. More recently, internal lengthening nails such as the PRECICE nail have been employed to facilitate distraction osteogenesis without the added complexity of external fixation.

AREAS COVERED

This review will examine the literature on the indications, design, and safety of the PRECICE nail (NuVasive) for intercalary reconstruction after tumor resection.

EXPERT OPINION

Bone transport using the PRECICE nail represents a viable alternative to Ilizarov distraction and has the benefit of avoiding the complications of an external fixator. For large defects, the PRECICE nail can be supplemented with a locking plate for additional stability and maintenance of limb length.