Dissociation of a Femoral Intramedullary Magnetic Lengthening Nail During Routine Hardware Removal: A Case Report

Surgical Technique for Removal of Old Universal Slotted AO Femoral Nail: A Case Report

This paper presents a surgical technique for the removal of an old universal femoral nail preceding total hip arthroplasty (THA) in a 50-year-old male patient with left hip osteoarthritis. The patient had undergone femur nail insertion approximately 35 years ago. Due to the necessity of nail removal prior to THA, surgery to remove the nail was planned. There are challenges posed by the design of the old universal femoral nail system, particularly its side slot which made engagement of the conical bolt difficult. The successful removal of the nail was eventually achieved, enabling subsequent THA. Individuals who received this old implant years ago may now require its removal as part of osteoarthritis treatment. Given the lack of familiarity among surgeons with this outdated implant, this paper is aimed at providing essential guidance and insights regarding its removal procedure. This literature represents the inaugural documentation of the surgical technique for the removal of an aged femur nail.

Disintegration of Multiple Parts of a Bone Transport Nail During Planned Removal: A Case Report

CASE

A 34-year-old man with a distal tibia bone defect was treated with an intramedullary bone transport nail (Precice Bone Transport System, NuVasive). During planned removal after successful treatment, 7 separate subcomponents of the nail became disconnected and had to be separately removed using specialized instrumentation. This occurred despite adherence to the manufacturer's recommended technique for nail removal and in the absence of clinical or radiographic evidence of implant failure.

CONCLUSION

When planning for implant removal, surgeons should be aware of potential intraoperative disconnection of subcomponents of this magnetic bone transport nail and ensure that equipment for retrieval (e.g., very long endoscopy forceps) is available.

Removal of broken PRECICE Stryde intramedullary lengthening nails

This paper describes two different techniques for removal of broken Precice Stryde intramedullary bone lengthening nails, which unlike trauma nails are solid containing mechanical components. Consequently, surgeons face unique challenges when these implants brake within medullary canal. Here, we present our surgical approach for removal of three broken implants. In one patient (46kg) both Ø10mm femoral Stryde implants (max. weight allowance 68kg) broke through the proximal locking screw hole preoperatively on the right side and intraoperatively on the left side (413 and 504 days after index surgery respectively). The third Ø11.5 femoral nail broke through the area containing the magnet (55kg patient, 325 days after index surgery). LEVEL OF EVIDENCE: IV.

Biopsy Proven Focal Osteolysis in a Stainless-Steel Limb-Lengthening Device: A Report of Three Cases

Three pediatric patients presented with histologically confirmed osteolysis after limb lengthening with a magnetic, telescoping, stainless-steel device. The first patient's findings were discovered radiographically before routine removal of the device. In all cases, intraoperative histologic specimens taken from around the modular junction demonstrated particle-laden macrophages with suspicion for metal debris. Silicone debris was also identified.

We found definitive osteolysis secondary to metal at the modular junction of three stainless-steel lengthening implants. This process is not well-understood in the setting of limb lengthening and should be examined further.

The STRYDE limb lengthening nail is susceptible to mechanically assisted crevice corrosion: an analysis of 23 retrieved implants

Background and purpose - We noted several adverse events in patients in whom the first version of the STRYDE limb-lengthening nail (NuVasive Specialized Orthopaedics, San Diego, CA) had been implanted. Pain, osteolysis, periosteal reactions, and cortical hypertrophy at the nail junction were noted. Here, we present the analysis of 23 retrieved STRYDE implants.Materials and methods - We undertook visual inspection of the retrieved nails and screws, mechanical evaluation of the junction, micro-CT analyses, microscopic inspection of the bushing, screws, screw holes, and separated parts of the implants. Positive material identification (PMI) and energy-dispersive X-ray spectroscopy (EDS) were used to analyze the chemical composition. The hardness of the material was also investigated.Results - 20/23 retrieved nails had visible signs of corrosion, i.e., discoloration at the telescopic junction. Micro-CT verified corrosion attacks in 12/12 scanned bushings. Corrosion, predominantly mechanically assisted crevice corrosion, was observed at the locking screws and screw holes in 20/23 nails. Biological material inside the nail was observed in addition to oozing from the junction of 2 nails during hardware removal, which was experimentally reproducible. Notably, the mechanical construction of the bushing changed from PRECICE P2 to STRYDE nails.Interpretation - STRYDE nails are not hermetically sealed, and liquid can pass the bushing. Biodur 108 itself is corrosion resistant; however, mechanically assisted crevice corrosion of the bushing, locking screws, and screw holes may be aggravated due to manufacturing aiming for increased strength and hardness of the alloy.Observing several adverse events, we recently published a nationwide cross-sectional analysis of all 30 STRYDE limb- lengthening nails (NuVasive, Specialized Orthopedics, San Diego, CA) that were implanted in Denmark (Rölfing et al. 2021a). 27/30 STRYDE nails have now been removed and we present data from metallurgical analysis of 23 of the retrieved implants.

Focal osteolysis and corrosion at the junction of Precice Stryde intramedullary lengthening device : preliminary clinical, radiological, and metallurgic analysis of 57 lengthened segments

Aims

This study aims to enhance understanding of clinical and radiological consequences and involved mechanisms that led to corrosion of the Precice Stryde (Stryde) intramedullary lengthening nail in the post market surveillance era of the device. Between 2018 and 2021 more than 2,000 Stryde nails have been implanted worldwide. However, the outcome of treatment with the Stryde system is insufficiently reported.

Methods

This is a retrospective single-centre study analyzing outcome of 57 consecutive lengthening procedures performed with the Stryde nail at the authors’ institution from February 2019 until November 2020. Macro- and microscopic metallographic analysis of four retrieved nails was conducted. To investigate observed corrosion at telescoping junction, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX) were performed.

Results

Adjacent to the nail’s telescoping junction, osteolytic changes were observed in bi-planar radiographs of 20/57 segments (35%) after a mean of 9.5 months (95% confidence interval 7.2 to 11.9) after surgery. A total of 8/20 patients with osseous alterations (40%) reported rest and ambulation pain of the lengthened segment during consolidation.

So far, 24 Stryde nails were retrieved and in 20 (83%) macroscopic corrosion was observed at the nail’s telescoping junction. Before implant removal 11/20 radiographs (55%) of lengthened segments with these 20 nails revealed osteolysis. Implant retrieval analysis by means of SEM showed pitting and crevice corrosion. EDX detected chromium as the main metallic element of corrosion.

Conclusion

Patients are exposed to the risk of implant-related osteolysis of unclear short- and long-term clinical consequences. The authors advocate in favour of an early implant removal after osseous consolidation.

Cite this article: Bone Joint Res 2021;10(7):425–436.