Symptomatic cord compression by paraspinal musculature following cervical laminectomy: rare complication

Brushite-coated Mg-Nd-Zn-Zr alloy promotes the osteogenesis of vertebral laminae through IGF2/PI3K/AKT signaling pathway

Biodegradable magnesium (Mg) alloys have been extensively investigated in orthopedic implants due to their suitable mechanical strength and high biocompatibility. However, no studies have reported whether Mg alloys can be used to repair lamina defects, and the biological mechanisms regulating osteogenesis are not fully understood. The present study developed a lamina reconstruction device using our patented biodegradable Mg-Nd-Zn-Zr alloy (JDBM), and brushite (CaHPO₄·2H₂O, Dicalcium phosphate dihydrate, DCPD) coating was developed on the implant. Through in vitro and in vivo experiments, we evaluated the degradation behavior and biocompatibility of DCPD-JDBM. In addition, we explored the potential molecular mechanisms by which it regulates osteogenesis. In vitro, ion release and cytotoxicity tests revealed that DCPD-JDBM had better corrosion resistance and biocompatibility. We found that DCPD-JDBM extracts could promote MC3T3-E1 osteogenic differentiation via the IGF2/PI3K/AKT pathway. The lamina reconstruction device was implanted on a rat lumbar lamina defect model. Radiographic and histological analysis showed that DCPD-JDBM accelerated the repair of rat lamina defects and exhibited lower degradation rate compared to uncoated JDBM. Immunohistochemical and qRT-PCR results showed that DCPD-JDBM promoted osteogenesis in rat laminae via IGF2/PI3K/AKT pathway. This study shows that DCPD-JDBM is a promising biodegradable Mg-based material with great potential for clinical applications.

A Case of Spinal Cord Compression Due to Paraspinal Musculature After Cervical Laminectomy

BACKGROUND

Only a few cases of spinal cord compression after cervical laminectomy have been reported.

CASE DESCRIPTION

We report a case of tetraparesis after executing a C3-C6 anterior and posterior decompression and fusion. Cervical magnetic resonance imaging demonstrated a spinal cord compression due to the impingement of the paraspinal muscles through the laminectomy. The patient experienced a spontaneous neurological recovery and the follow-up cervical magnetic resonance imaging showed resolution of the spinal cord compression.

CONCLUSIONS

This rare complication should be considered among the others after executing a cervical laminectomy.

Dynamic Cervical Cord Compression Post-laminectomy Visualized by Flexion-extension Magnetic Resonance Imaging: Case Report

Flexion-extension magnetic resonance imaging (MRI) in the cervical spine is not universally used in cervical spine surgery. However, flexion-extension MRIs can identify previously undetected spinal stenosis, improve surgical decision-making, and maybe a better tool to evaluate postoperative outcomes. One uncommon complication after laminectomy, to treat cervical spinal stenosis, is muscle weakness due to subsequent dynamic cord compression by posterior paraspinal musculature. We present a case of a 41-year-old male who underwent posterior cervical decompression and developed subsequent neurological deficits and muscle weakness. MRI with neutral cervical positioning did not show spinal stenosis necessitating surgical intervention. However, given the patient’s increasing tetraparesis, flexion-extension MRI was performed and it revealed significant spinal stenosis in both flexion and extension positions due to spondylosis and compression from paraspinal muscles. This case demonstrates the utility of flexion-extension MRI in identifying pathologies such as cord compression by paraspinal muscles. Exclusive use of a neutral-position MRI scan may not be sufficient to provide proper diagnoses for cervical spine pathologies. Flexion-extension MRI should be considered when the degree of neurological symptoms outweighs minimal or absent pathology seen on neutral-position sagittal MRI.