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.

All-Internal Limb Lengthening with Simultaneous Corrective Osteotomy After Internal Hemipelvectomy: A Case Report

CASE

A 27-year-old woman with a Grade II chondrosarcoma in the right acetabulum underwent a Type II internal hemipelvectomy with an ischiofemoral fusion. She developed a 7.0-cm functional limb-length discrepancy with adduction of the hip at rest. Four years after surgery, she underwent a corrective osteotomy and limb lengthening with a magnetic lengthening nail. Eleven years after tumor resection and a successful pregnancy, she had symmetric leg lengths and ambulated without an assistive device.

CONCLUSIONS

A magnetic lengthening nail is a viable option for correcting limb-length discrepancies after hemipelvectomy. If necessary, a simultaneous corrective proximal femoral osteotomy can be performed.

Robotic assistance for quick and accurate image-guided needle placement

Computed tomography (CT) image-guided procedures including biopsy, drug delivery, and ablation are gaining increasing application in medicine. Robotic technology holds the promise for allowing surgeons, and other proceduralists, access to such CT-guided procedures by potentially shortening training, improving accuracy, decreasing needle passes, and reducing radiation exposure. We evaluated surgeon learning and proficiency for image-guided needle placement with an FDA-cleared robotic arm. Five out of six surgeons had no prior CT-guided procedural experience, while one had prior experience with freehand CT-guided needle placement. All surgeons underwent a 60-min training with the MAXIO robot (Perfint Healthcare, Redmond, WA). The robot was used to place needles into three different pre-specified targets on a spine model. Performance time, procedural errors, and needle placement accuracy were recorded. All participants successfully placed needles into the targets using the robotic arm. The average time for needle placement was 3:44 ± 1:43 min. Time for needle placement decreased with subsequent attempts, with average third placement taking 2:29 ± 1:51 min less than the first attempt. The average vector distance from the target was 2.3 ± 1.2 mm. One error resulted in the need for reimaging by CT scan. No errant needle placement occurred. Surgeons (attending fellows and residents) without previous experience and minimal training could successfully place percutaneous needles under CT guidance quickly, accurately, and reproducibly using a robotic arm. This suggests that robotic technology may be used to facilitate surgeon adoption of CT image-guided needle-based procedures in the future.

Long-Term Follow-up of High-Dose Chemotherapy with Autologous Stem Cell Transplantation in Children and Young Adults with Metastatic or Relapsed Ewing Sarcoma: A Single-Institution Experience

Forty-seven patients with metastatic disease at diagnosis or recurrent Ewing sarcoma (EWS) received high-dose chemotherapy (HDC) followed by tandem (n = 20, from February 13, 1997, to October 24, 2002) or single (n = 27, from October 1, 2004, to September 5, 2018) autologous hematopoietic stem cell transplantation (ASCT). To our knowledge, this is the largest single-institution study with sustained long-term follow-up exceeding 10 years. All patients who underwent single ASCT received a novel conditioning regimen with busulfan, melphalan, and topotecan. The overall survival (OS) and disease-free survival (DFS) were 46% and 37% at 10 years and 42% and 37% at 15 years, respectively. Disease status at transplant and the time to disease relapse prior to ASCT were identified as important prognostic factors in OS, DFS, and risk of relapse. At 10 years, patients who underwent transplantation in first complete response (1CR) had an excellent outcome (OS 78%), patients in 1CR/second complete response (2CR)/first partial response (1PR) had an OS of 66%, and patients at third or more complete response, second or more partial response, or advanced disease had an OS of 26%. Ten-year OS for patients without a history of relapse, with late relapse (≥2 years from diagnosis), or with early relapse (<2 years from diagnosis) was 75%, 50%, and 18%, respectively. Selected patients in 1CR, 2CR, 1PR, and with late relapse had excellent, sustained 10- and 15-year OS and DFS.

Treatment of multidirectionally unstable supracondylar humeral fractures in children. A modified Gartland type-IV fracture

BACKGROUND

There is an uncommon subset of supracondylar humeral fractures in children that are so unstable they can displace into both flexion and extension. The purposes of this study were to describe this subset of supracondylar fractures and to report a new technique of closed reduction and percutaneous pinning for their treatment.

METHODS

In a retrospective review of 297 consecutive displaced supracondylar humeral fractures in children treated operatively at our institution, we identified nine that were completely unstable with documented displacement into both flexion and extension as seen on fluoroscopic examination with the patient under anesthesia. We used a new technique for closed reduction and fixation of these fractures, and then we assessed fracture-healing and complications from the injury and treatment.

RESULTS

All nine fractures were treated satisfactorily with closed reduction and percutaneous pinning. The complication rate associated with these unstable fractures was no higher than that associated with the 288 more stable fractures. Seven of the nine fractures were stabilized with lateral entry pin placement, and two fractures were stabilized with crossed medial and lateral pins. None of the patients had a nonunion, cubitus varus, malunion, additional surgery, or loss of motion.

CONCLUSIONS

In rare supracondylar fractures in children, multidirectional instability results in displacement into flexion and/or extension. This fracture can be classified as type IV according to the Gartland system, as it is less stable than a Gartland type-III extension supracondylar fracture. These fractures can be treated successfully with a new technique of closed reduction and percutaneous pinning, thus avoiding open reduction.

Access to orthopedic care for children with medicaid versus private insurance in California

OBJECTIVE

To compare the availability of timely orthopedic care to a child with a fractured arm insured by Medi-Cal (California state Medicaid) and by private insurance.

STUDY DESIGN

Fifty randomly chosen offices of orthopedic surgeons were telephoned with the following scenario: "My 10-year-old son broke his arm last week during a vacation" followed by a request for an appointment that week. Each office was called twice with an identical script except for insurance status: once with Medi-Cal and once with private insurance.

RESULTS

All 50 offices offered an appointment to see the child with private insurance within 7 days. Only 1 of the same 50 offices offered an appointment to see the child with Medi-Cal within 7 days. Of the offices that would not see a child with Medi-Cal, 87% were unable to recommend an orthopedic office that accepted Medi-Cal.

CONCLUSIONS

Timely access to orthopedic care was available in 100% of offices polled to a child with private insurance versus in 2% of offices to a child with Medi-Cal. This is a significant difference. Lack of timely orthopedic care may result in poor outcome, ie, if a fracture is not properly aligned in the first few weeks, a permanent deformity may result. Although causation cannot be established from this study, we suspect that Medi-Cal reimbursement rates below the cost of office overhead may be of significance. Although federal guidelines require that payments must be sufficient to enlist enough providers so that services to Medi-Cal recipients are available to the same extent as those available to the general population, this study finds that that children with Medi-Cal insurance have significantly less access to timely orthopedic care.