Occipitocervical reconstruction through direct lateral and posterior approach for the treatment of primary osteosarcoma in the atlas: a case report

Reconstruction of C1 lateral mass with an expandable cage in addition to vertebral artery preservation: presenting two cases

PURPOSE

C1 lateral mass reconstruction is recommended, in cases of instability caused by tumor involvement or extensive C1 lateral mass resection. However, because of the anatomical complexity of the area and, most importantly, the proximity to vertebral arteries, few cases of reconstruction have been reported to date. The purpose of this report is to present technical details of C1 lateral mass reconstruction in conjunction with vertebral artery preservation from a posterior approach.

METHODS

Two cases of one stage craniovertebral junction instrumentation and C1 lateral mass reconstruction in conjunction with vertebral artery preservation from a posterior approach are presented.

RESULTS

In both cases of extensive resection of lateral mass due to tumor involvement, an expandable cage was used for C1 lateral mass reconstruction, which has been used only in one patient in literature. Complementary pathological examinations of the two cases indicated two rare tumors that had been reported in the upper cervical region so far. The first case became an unknown origin metastatic cancer and the second was reported to be a primary non- Hodgkin lymphoma.

CONCLUSIONS

C1 lateral mass reconstruction with an expandable cage together with VA preservation is recommended in cases of extensive C1 lateral mass resection to increase the total strength and to shorten the length of the posterior device and probably better fusion. The expandable cage is preferred because of safer placement under compression instead of the lateral mass.

A case report: Bilateral reconstruction of C2 lateral masses with expandable titanium cages following axis (C2) solitary plasmacytoma resection with 2-year follow-up

Background

Solitary plasmacytoma (SP) caused the collapse/destruction of the C2 vertebral body in a 78-year-old male. To provide sufficient posterior stabilization, the patient warranted lateral mass fusion to supplement the bilateral pedicle/screw rod instrumentation.

Case Description

A 78-year-old male presented with neck pain alone. X-rays, computed tomography, and magnetic resonance studies documented C2 vertebral collapse with the complete destruction of both lateral masses. The surgery required a laminectomy (i.e., bilateral lateral mass resection), plus placement of bilateral expandable titanium cages from C1 to C3 to supplement the screw/rod occipitocervical (O-C4) fixation. Adjuvant chemotherapy and radiotherapy were also administered. Two years later, the patient remained neurologically intact and radiographically had no evidence of tumor recurrence.

Conclusion

In patients with vertebral plasmacytomas and bilateral lateral mass destruction, posterior occipital-cervical C4 rod/screw fusions may warrant the additional bilateral placement of titanium expandable lateral mass cages from C1 to C3.

MicroRNA-493-5p inhibits proliferation and metastasis of osteosarcoma cells by targeting Kruppel-like factor 5

Osteosarcoma, including spinal osteosarcoma, has properties of high degree of malignancy, high rate of recurrence, and high incidence of metastasis. microRNAs can exert oncogenic or tumor suppressive roles in cancer cells. This study explored the effects of microRNA-493-5p (miR-493-5p) on osteosarcoma cell viability, migration, invasion, and apoptosis, as well as the underlying possible mechanism. First, the expression of miR-493-5p in osteosarcoma tissues and cells was detected using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Then, the effects of miR-493-5p overexpression (or suppression) on osteosarcoma cell viability, migration, invasion, and apoptosis, as well as Kruppel-like factor 5 (KLF5) expression, were assessed using the Cell Counting Kit-8 assay, two-chamber transwell assay, Annexin V-FITC/PI apoptosis detection kit, qRT-PCR, and western blotting, respectively. Finally, the roles of KLF5 in miR-493-5p suppression-induced U20S cell viability, migration, and invasion enhancement, as well as the PI3K/AKT pathway activation, were evaluated. We found that miR-493-5p had lower expression in tumor tissues of spinal osteosarcoma and osteosarcoma cells. Overexpression of miR-493-5p inhibited osteosarcoma U20S cell viability, migration, and invasion, but induced cell apoptosis. On the contrary, suppression of miR-493-5p-promoted U20S cell viability, migration, and invasion. KLF5 was a direct target gene of miR-493-5p, which participated in the effects of miR-493-5p on U20S cell viability, migration, invasion, and apoptosis. Furthermore, suppression of the miR-493-5p activated PI3K/AKT pathway in U20S cells by upregulating KLF5. In conclusion, we revealed that miR-493-5p exerted tumor suppressive roles in spinal osteosarcoma and osteosarcoma cells. Overexpression of miR-493-5p inhibited proliferation and metastasis of osteosarcoma cells by downregulating KLF5 and inactivating the PI3K/AKT signaling pathway.

Bilateral C-1 lateral mass reconstruction following radical resection of a giant osteoblastoma of the atlas: case report

Osteoblastoma is a rare, benign, osteoid-producing, and slow-growing primary bone tumor, typically arising in long bones or in the spine, with a slight male predominance. This report describes the surgical treatment of a giant C-1 (atlantal) osteoblastoma diagnosed in a young male patient with neurofibromatosis Type 1. The authors describe the clinical presentation, the surgical procedure for complete excision and stabilization, and results as of the 1-year follow-up. They detail a bilateral occipitoaxial spinal interarticular stabilization technique that they used after complete tumor excision. To the best of their knowledge, this is the first case of bilateral C-1 lateral mass reconstruction by this technique to be reported in the literature.

Fusion following lateral mass reconstruction in the cervical spine

OBJECT

Recently, aggressive surgical techniques and a push toward en bloc resections of certain tumors have resulted in a need for creative spinal column reconstruction. Iatrogenic instability following these resections requires a thoughtful approach to adequately transfer load-bearing forces from the skull and upper cervical spine to the subaxial spine.

METHODS

The authors present a series of 7 cases in which lateral mass reconstruction with a cage or fibular strut graft was used to provide load-bearing support, including 1 case of bilateral cage placement.

RESULTS

The authors discuss the surgical nuances of en bloc resection of high cervical tumors and explain their technique for lateral mass cage placement. Additionally, they provide their rationale for the use of these constructs throughout the craniocervical junction and subaxial spine.

CONCLUSIONS

Lateral mass reconstruction provides a potential alternative or adjuvant method of restoring the load-bearing capabilities of the cervical spine.

Occipitoaxial spinal interarticular stabilization with vertebral artery preservation for atlantal lateral mass failure

The treatment of craniocervical instability caused by diverse conditions remains challenging. Different techniques have been described to stabilize the craniocervical junction. The authors present 2 cases in which tumoral destruction of the C-1 lateral mass caused craniocervical instability. A one-stage occipitoaxial spinal interarticular stabilization (OASIS) technique with titanium cages and posterior occipitocervical instrumentation was used to reconstruct the C-1 lateral mass and stabilize the craniocervical junction. The ipsilateral vertebral artery was preserved. The OASIS technique offers single-stage tumor resection, C-1 lateral mass reconstruction, and stabilization with a loadsharing construct. It could be an option in the treatment of select cases of C-1 lateral mass failure.

Transoral approach for percutaneous vertebroplasty in the treatment of osteolytic tumor lesions of the lateral mass of the atlas: feasibility and initial experience in 2 patients

STUDY DESIGN

Case series.

OBJECTIVE

To report our early experience of percutaneous vertebro-plasty via a transoral approach of the lesions of the lateral mass of C1.

SUMMARY OF BACKGROUND DATA

Percutaneous vertebroplasty has gained acceptance for the treatment of osteolytic lesions of the spine. However, scant data are available on the percutaneous vertebroplasty of the C1 lesions.

METHODS

Two patients (a 74-yr-old female and a 53-yr-old male) presenting respectively a metastasis of the left lateral mass of C1 from a pancreatic adenocarcinoma and a hemangioma of the left lateral mass of C1 underwent a percutaneous vertebroplasty via a transoral approach in a hybrid angio suite associating a monoplane flat panel and a computed tomography scan, using polymethylmetacrilate bone cement.For the second patient, a nondetachable balloon was used to protect the vertebral artery from cement leakage.

RESULTS

Satisfactory filing of the lesions was obtained in both patients. No complication was recorded. Both patients experienced pain improvement.

CONCLUSION

Transoral approach for the treatment of osteolytic tumor lesions of the lateral mass of the atlas is feasible and seems to be a safe and effective technique.