Review Question - QID 211124

The patient underwent a cervical laminoplasty, which is indicated for multilevel cervical myelopathy with preserved cervical lordosis. Of the choices, Figure A depicts multilevel congenital cervical stenosis with preserved cervical lordosis.

Cervical laminoplasty is an effective treatment for multilevel cervical stenosis that preserves cervical motion. Indications include preserved cervical lordosis and lack of axial neck pain, which suggests fusion would better address arthritic facets and discs. Laminoplasty can either be performed using an open door technique or a French door technique. An ideal surgical candidate would have multilevel congenital cervical stenosis. Ossification of the posterior longitudinal ligament has been a classic example, but there are concerns over the progression of ossification with motion preservation.

An et al. performed a review of the surgical treatment for OPLL and recommended operative treatment for patients with Nurick grade 3 or 4 myelopathy. Surgical approach depended on the percentage of canal encroachment by the ossification, and the presence or absence of cervical lordosis. Anterior surgery is recommended for > 60% canal encroachment and cervical kyphosis, whereas posterior surgery alone is preferred with preserved lordosis with laminoplasty but poses the risk of progressive kyphosis.

Chen et al. performed a retrospective study of 138 patients undergoing surgical treatment for OPPL. There was a 45% dural tear rate in the 40 patients with ossified dura. The double-layer sign on preoperative CT scan was found to be more sensitive for mild OPLL rather than severe OPLL, 81% versus 26.3% respectively. The authors concluded that increased severity results in ossification of the intervening PLL, which can result in a false negative.

Figure A demonstrates a sagittal T2 MRI of the cervical spine demonstrating preserved cervical lordosis with multilevel cervical stenosis from C2 to C7, with illustration A depicting post-op lateral radiograph after a laminoplasty from C3-6. Figure B demonstrates a sagittal CT scan of the cervical spine with OPLL in a mixed pattern from C4 to C7 with cervical kyphosis. Figure C demonstrates a herniated nucleus pulposus at C5-6 causing cord compression. Figure D demonstrates a sagittal CT with multilevel kyphotic cervical spondylosis. Figure E demonstrates a sagittal T2 MRI with a metastatic lesion of the C4 vertebral body.

Incorrect Answers:
Answer 2: This figure demonstrates OPPL with extensive involvement behind the vertebral bodies and a kyphotic spine. The best approach to address this would be anterior decompression with corpectomies and strut grafting. Laminoplasty will not address the sites of decompression in this case.
Answer 3: This figure demonstrates a herniated nucleus pulposus at C5-6, which would require a C5-6 ACDF to sufficiently decompress. Laminoplasty would not be a good choice for this pathology since it is anterior and focal.
Answer 4: This figure demonstrates multilevel cervical spondylosis with severe cervical kyphosis. The best approach for this would require a combined anterior and posterior approach to correct the kyphosis and decompress posteriorly.
Answer 5: This figure demonstrates a metastatic lesion for the C4 vertebral body. This would best be addressed with a C4 corpectomy and fusion.