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.

Reconstruction of Bony Defects With Motorized Intramedullary Nails After Tumor Resection

Motorized intramedullary lengthening nails allow for transport of a bone segment for limb lengthening, deformity correction, healing of nonunion, and intercalary distraction osteogenesis. Resection of tumors involving the bone can result in substantial defects that require reconstruction. Use of these nails allows for a biologic reconstruction with the incorporation of allograft or by distraction osteogenesis. Limb lengthening after an internal hemipelvectomy where the hip joint is resected can be performed to improve gait, decrease pain, and prevent the need for a custom shoe or shoe lift. Using these nails in compression aids the incorporation of intercalary allografts and prevents stress shielding and stress risers within the graft when compared with plating. It also allows for a subsequent lengthening of the limb using the same implant. Plate-assisted bone segment transport or the use of a bone transport nail allows for a true biologic reconstruction of an intercalary defect using distraction osteogenesis. These implants provide the orthopaedic oncologist with more options for reconstruction and the potential to improve the function and outcomes of their patients.

Role of immunotherapy in chondrosarcoma: A case report and review of the literature

Chondrosarcomas (CSs) consist of a heterogenous group of primary bone cancers arising from malignant cells which produce cartilaginous matrix. As the second most common primary bone cancer, CS are often resistant to systemic chemotherapy due to poor vascularization, slow proliferation, and expression of multidrug-resistant pumps. Immune checkpoint inhibitors have transformed the field of oncology and are now designated as frontline therapy for many solid tumor cancers. Several studies have demonstrated increased expression of programed cell death 1 (PD-1) and PD-L1 in CS tissue in vitro, which has led to the development of multiple clinical trials for immunotherapy in patients with aggressive CS. In this review, we highlight the ongoing investigation into the role for immunotherapy in CS. We also report the case of a 44-year-old female with a history of stage IV primary CS of the right shoulder who underwent radical resection with recurrence and demonstrated a spectacular sustained response to pembrolizumab at our center. Our review highlights the need for further studies investigating the role of immunotherapy in the treatment of aggressive bone sarcomas that are resistant to standard surgical resection, chemotherapy, and radiation treatment.

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.

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

INTRODUCTION

Traditionally, distraction osteogenesis has been accomplished with an external fixator. All internal transport utilizing magnetic intramedullary nails is a newer technique for bone reconstruction. The Precice Bone Transport Nail is a new implant that allows for noninvasive transport via a magnetically driven motor.

AREAS COVERED

This report describes the function of the Bone Transport Nail along with the technical considerations on how to successfully manage bone defects with this new technology. Appropriate use of the nail, preoperative planning, intraoperative considerations, and postoperative management are discussed in detail.

EXPERT OPINION

The Precice Bone Transport Nail utilizes the technology of the original Precice nail to provide an all-internal option for reconstruction of intercalary defects. This obviates the need for an additional plate with a standard Precice nail when performing bone transport and allows for a less invasive option that decreases operating room time. It provides a more cosmetic result than external fixation and avoids the risks of pin tract infection. Preoperative planning is essential to appropriate execution of the operative procedure and to perform a successful transport. A thorough understanding of the nail design and limitations are a prerequisite as this implant is significantly different from a standard intramedullary nail.

Comparison of forces generated using compression plating versus a magnetic lengthening nail in a sawbones femur model

BACKGROUND

The purpose of this study is to compare compression generated by a Precice magnetic lengthening intramedullary nail and a 5.0 mm limited contact dynamic compression plate.

METHODS

Transverse osteotomy sites were created in the femoral shaft of ten Sawbones fourth generation composite femurs. Antegrade 10-degree trochanteric Precice nails and 8-hole, 5.0 mm plates were used for fixation. The plates were compressed by placing a neutral screw and three eccentrically drilled compression screws on alternating sides of the osteotomy. Average compression and distribution of compression were compared, and P-values <0.05 were considered statistically significant.

FINDINGS

The Precice nail generated an average of 2.38 megapascal across the osteotomy sites. The plate generated an average of 0.70 megapascal (P < 0.001) with the initial compression screw, 0.93 megapascal (P < 0.001) after the second screw, and 1.04 megapascal (p < 0.001) after the final screw. The distribution of compression was assessed utilizing a polar transformation to compare pressure values. We found that the distribution of compression was more circumferentially uniform in the Precice nail group (P = 0.046).

INTERPRETATION

This study demonstrates that an electromagnetic intramedullary device is capable of generating significantly higher compression, in a more uniform distribution, than a 5.0 mm limited contact dynamic compression plate in a Sawbones model. The results indicate that electromagnetic intramedullary nail systems may be an ideal alternative to compression plating for treatment of at-risk fractures, nonunions, delayed unions, and intercalary allograft reconstruction.

Ultrasound-Assisted Posterior Knee Arthroscopy: A Description of the Technique

Entering the posterior knee with arthroscopy can be difficult. Scar tissue, a tumor, and the obese patient can make instrument placement difficult and risk iatrogenic injury. Ultrasound can be used to visualize the posterior knee and provide direct guidance of instrumentation. We describe the technique and indications for using ultrasound during arthroscopy. Accurate and atraumatic insertion of instruments can be performed with no damage to total knee components or the knee joint. Ultrasound guidance should be considered during difficult posterior knee arthroscopy.

Unusual presentation in Haiti of a recurrent giant cell tumor of bone affecting the distal radius: A case report

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En bloc resection with centralization is a viable approach in low-resource areas.

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Multidisciplinary surgical approaches are necessary in low-resource settings.

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Loss of motion can be compensated with proper rehabilitation measures.

Introduction

Giant cell tumor of bone (GCTB) is a benign-aggressive tumor that has a high-rate of recurrence with curettage resection alone. Patients with GCTB in underserved regions of the world can have progression of the tumor with significant disability due to a lack of specialty care. We present a case of an en bloc resection of an aggressive, recurrent GCTB of the radius with excellent function and no evidence of tumor recurrence two years after surgery.

Presentation of case

A 22-year-old right-hand dominant female in Haiti developed an aggressive recurrence of a giant cell tumor of bone (GCTB) of the distal radius. Treatment consisted of en bloc resection of the distal radius with the proximal row of the carpus and centralization of the ulna. At two-year follow-up, the patient maintained good functional capacity with no clinical or radiological evidence of recurrence.

Discussion

GCTB can cause significant destruction of the bone and articular surface if not treated adequately. Treatment options should be considered carefully in underserved regions of the world based on the resources available. This case exemplifies that complex limb-salvage surgery is possible when coordination of care between international and local surgeons is provided with an emphasis on continuity of care post-operatively.

Conclusion

En bloc resection with centralization of the ulna remains a viable technique to address aggressive GCTB of the distal radius and can be appropriate in resource-limited settings.

Bupivacaine and Lidocaine Induce Apoptosis in Osteosarcoma Tumor Cells

BACKGROUND

Osteosarcoma is the most common type of bone cancer in adolescents. There have been no significant improvements in outcomes since chemotherapy was first introduced. Bupivacaine and lidocaine have been shown to be toxic to certain malignancies. This study evaluates the effect of these medications on two osteosarcoma cell lines.

QUESTIONS/PURPOSES

(1) Does incubation of osteosarcoma cells with bupivacaine or lidocaine result in cell death? (2) Does this result from an apoptotic mechanism? (3) Is a specific apoptotic pathway implicated?

METHODS

Two cell lines were chosen to account for the inherent heterogeneity of osteosarcoma. UMR-108 is a transplantable cell line that has been used in multiple studies as a primary tumor. MNNG/HOS has a high metastatic rate in vivo. Both cell lines were exposed bupivacaine (0.27, 0.54, 1.08, 2.16, 4.33 and 8.66 mM) and lidocaine (0.66, 1.33, 5.33, 10.66, 21.32 and 42.64 mM) for 24 hours, 48 hours, and 72 hours. These concentrations were determined by preliminary experiments that found the median effective dose was 1.4 mM for bupivacaine and 7.0 mM for lidocaine in both cell lines. Microculture tetrazolium and colony formation assay determined whether cell death occurred. Apoptosis induction was evaluated by phase-contrast micrographs, flow cytometry, DNA fragmentation and reactive oxygen species (ROS). The underlying pathways were analyzed by protein electrophoresis and Western blot. All testing was performed in triplicate and compared with pH-adjusted controls. Quantitative results were analyzed without blinding.

RESULTS

Both medications caused cell death in a dose- and time-dependent manner. Exposure to bupivacaine for 24 hours reduced viability of UMR-108 cells by 6 ± 0.75% (95% CI 2.9 to 9.11; p = 0.01) at 1.08 mM and 89.67 ± 1.5% (95% CI 82.2 to 95.5; p < 0.001) at 2.16 mM. Under the same conditions, MNNG/HOS viability was decreased in a similar fashion. After 24 hours, the viability of UMR-108 and MNNG/HOS cells exposed to 5.33 mM of lidocaine decreased by 25.33 ± 8.3% (95% CI 2.1 to 48.49; p = 0.03) and 39.33 ± 3.19% (95% CI 30.46 to 48.21; p < 0.001), respectively, and by 90.67 ± 0.66% (95% CI 88.82 to 92.52; p < 0.001) and 81.6 ± 0.47% (95% CI 79.69 to 82.31; p < 0.001) at 10.66 mM, respectively. After 72 hours, the viability of both cell lines was further reduced. Cell death was consistent with apoptosis based on cell morphology, total number of apoptotic cells and DNA fragmentation. The percentage increase of apoptotic UMR-108 and MNNG/HOS cells confirmed by Annexin-V positivity compared with controls was 21.3 ± 2.82 (95% CI 16.25 to 26.48; p < 0.001) and 21.23 ± 3.23% (95% CI 12.2 to 30.2; p = 0.003) for bupivacaine at 1.08 mM and 25.15 ± 4.38 (95% CI 12.9 to 37.3; p = 0.004) and 9.11 ± 1.74 (95% CI 4.35 to 13.87; p = 0.006) for lidocaine at 5.33 mM. The intrinsic apoptotic pathway was involved as the expression of Bcl-2 and survivin were down-regulated, and Bax, cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase-1 were increased. ROS production increased in the UMR-108 cells but was decreased in the MNNG/HOS cells.

CONCLUSION

These findings provide a basis for evaluating these medications in the in vivo setting. Studies should be performed in small animals to determine if clinically relevant doses have a similar effect in vivo. In humans, biopsies could be performed with standard doses of these medications to see if there is a difference in biopsy tract contamination on definitive resection.

CLINICAL RELEVANCE

Bupivacaine and lidocaine could potentially be used for their ability to induce and enhance apoptosis in local osteosarcoma treatment. Outcome data when these medications are used routinely during osteosarcoma treatment can be evaluated compared with controls. Further small animal studies should be performed to determine if injection into the tumor, isolated limb perfusion, or other modalities of treatment are viable.

Successful treatment of a dedifferentiated chondrosarcoma of the proximal humerus with a hemicortical articular surface sparing allograft: A case report

INTRODUCTION

Dedifferentiated chondrosarcomas are rare and highly malignant tumors that require wide surgical resection. Survival is extremely poor without adequate surgical margins. We present a case of articular sparing surgery of the shoulder for dedifferentiated chondrosarcoma with excellent functional outcomes and no evidence of disease after fifty-six months.

PRESENTATION OF CASE

A 29-year-old male was found to have a non-metastatic right proximal humerus dedifferentiated chondrosarcoma. He underwent resection with clear one centimeter margins sparing the medial cortex and the articular surface. Reconstruction of the bone was accomplished using a hemicortical allograft. A dermal allograft was used to help reconstruct the rotator cuff to the allograft bone. At fifty-six months after surgery he has excellent functional range of motion. His current MSTS, Quick Dash, and Constant Shoulder scores are 29, 2.3, and 80, respectively. He has remained free of disease, is back to work without restrictions and is active in outdoor activities.

DISCUSSION

Dedifferentiated chondrosarcoma has high recurrence and poor survival rates. Adequate surgical resection is vital for its treatment. Previously described reconstructive techniques have consisted of articular replacement with a prosthesis, allograft, or allograft-prosthetic composites. To our knowledge, this is the first report of an articular sparing reconstruction for dedifferentiated chondrosarcoma with fifty-six month survival and functional outcomes. When possible, sparing the articular surface can provide good functional outcomes that improve over time.

CONCLUSION

If adequate surgical margins can be obtained, an articular surface sparing reconstruction of the shoulder can provide effective functional outcomes and an alternative to joint replacement.

Antiproliferative effect of bupivacaine on patient-derived sarcoma cells

Sarcomas are rare tumors with limited treatment options. Although chemotherapy is standard for certain subtypes, overall survival has not improved in several decades. Bupivacaine has been shown to induce apoptosis and prevent cell growth in multiple different types of malignancies but has not been studied in sarcoma. The current study evaluated the effects of bupivacaine on multiple patient-derived sarcoma cells and a commercial sarcoma cell line. Multiple patient-derived sarcoma cell subtypes and a commercial synovial cell sarcoma cell line were exposed to bupivacaine for different durations and at different concentrations. The patient-derived cells included a high-grade conventional osteosarcoma, a high-grade undifferentiated pleomorphic sarcoma of bone, and a high-grade synovial sarcoma. Flow cytometry and an MTT assay were used to evaluate whether a treatment effect was observed. Treatment of all the subtypes of sarcomas in this study with bupivacaine demonstrated a time- and dose-dependent increase in apoptosis and decrease in cell viability. A cell viability assay demonstrated that the IC₅₀ was between 0.04 and 0.05% and that the treatment effect occurred at clinically relevant doses in vitro. Bupivacaine was toxic to both the patient-derived cells and the commercial cell line at doses commonly used in the clinical setting. These findings provide a foundation for further in vivo studies to evaluate whether these effects will translate to the clinical setting. Although further research is necessary, bupivacaine shows promise as not only an adjunct for pain management but as a treatment modality for sarcoma.

Development of multifocal extra-abdominal desmoid fibromatosis after surgical resection

Multifocal fibromatosis is a rare entity. We report on two cases where multifocal disease developed after surgical resection. Chronic inflammation and repetitive trauma may be considered a risk factor for developing multifocal disease.

The effect of non-steroidal anti-inflammatory drugs on osteosarcoma cells

OBJECTIVE

Osteosarcoma (OS), an aggressive malignancy, is the most common primary bone tumor in children. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to reduce pain and inflammation. NSAIDs have shown to be toxic to certain malignancies such as colorectal, breast, and pancreatic cancers, but are not well-studied in OS. The purpose of this study is to assess whether ketorolac induces apoptosis in OS cells, compare this to indomethacin, which has been shown to inhibit OS proliferation, and explore the underlying mechanism.

MATERIALS AND METHODS

A rat OS cell line (UMR-108) was exposed to various concentrations of ketorolac and indomethacin. Cell viability, cytotoxicity, apoptosis induction, DNA fragmentation and the expression of apoptosis-related markers were examined by MTT assay, colony formation assay, flow cytometry, agarose gel electrophoresis, and Western blot respectively.

RESULTS

The results indicated that ketorolac and indomethacin could induce apoptosis of rat OS cells in a dose- and time-dependent manner. Apoptosis was confirmed by cell morphology and annexin positivity. The molecular data showed that NSAIDs affected expression of Bcl-2, survivin, and Poly (ADP-ribose) polymerase-1 (PARP).

CONCLUSIONS

These findings demonstrated that NSAIDs induced apoptosis in rat OS cells in vitro. Further research focusing on the potential cytotoxicity of NSAIDs in vivo is needed.

Use of Magnetic Growing Intramedullary Nails in Compression During Intercalary Allograft Reconstruction

Traditionally, intercalary allograft reconstruction after tumor resection has had a high rate of complications, particularly nonunion. Plate and intramedullary nail fixation have been used alone and in combination to improve union rates. This study sought to evaluate a new technique that uses a magnetic growing intramedullary nail to compress the osteotomy sites to aid in healing and to answer 2 questions: (1) What is the union rate and the time to union when using magnetic growing intramedullary nails? (2) What complications occur with this technique? Eight patients with 15 osteotomy sites with a minimum follow-up of 14 months were retrospectively reviewed. Seven of the 8 patients underwent initial reconstruction with the magnetic nail, whereas 1 patient underwent treatment of a nonunion that occurred with prior carbon fiber nail fixation. Twelve of the 15 osteotomy sites had healed by an average of 9 months. Nonunions occurred in 2 patients with an associated failure of the hardware. One of these patients healed after revision surgery. Of the patients who healed at both sites, 1 had a fracture through the allograft, 1 had backing out of a locking screw that required removal, and 1 required a manipulation under anesthesia of the knee. Two patients underwent successful limb lengthening needed because of an expected limb-length discrepancy after healing occurred. Use of growing intramedullary nails in compression mode led to an 87% union rate at final follow-up with acceptable complications. This technique provides a viable alternative to standard nail and plate fixation when intercalary allografts are used. [Orthopedics. 2018; 41(6):330-335.].

Metastatic biomarkers in synovial sarcoma

Synovial sarcoma (SS) is an aggressive soft tissue sarcoma (STS) that typically occurs in the extremities near a joint. Metastatic disease is common and usually occurs in the lungs and lymph nodes. Surgical management is the mainstay of treatment with chemotherapy and radiation typically used as adjuvant treatment. Although chemotherapy has a positive impact on survival, the prognosis is poor if metastatic disease occurs. The biology of sarcoma invasion and metastasis remain poorly understood. Chromosomal translocation with fusion of the SYT and SSX genes has been described and is currently used as a diagnostic marker, although the full impact of the fusion is unknown. Multiple biomarkers have been found to be associated with SS and are currently under investigation regarding their pathways and mechanisms of action. Further research is needed in order to develop better diagnostic screening tools and understanding of tumor behavior. Development of targeted therapies that reduce metastatic events in SS, would dramatically improve patient prognosis.