Cervical Laminoplasty

Kazumasa Ueyama, Po-Quang Chen, and Seiko Harata

Goals of Surgical Treatment

Posterior decompression and reconstruction of the cervical spinal canal.

Diagnosis

Cervical myelopathy is diagnosed precisely by physical examination. We evaluate a patient’s status using the Japanese Orthopaedic Association’s (JOA) functional scoring system (full mark is 17 points).

Cervical instability, alignment, and sagittal spinal canal diameter (less than 13 mm) are checked by plain x-ray. Computed tomography (CT) is also effective in showing the spinal canal (Fig. 8–1), osteophytes, and ossification of the posterior longitudinal ligament (OPLL). Magnetic resonance imaging (MRI) shows the spinal cord, the subarachnoid space, and the intervertebral disc. The T2 high-intensity area in the spinal cord indicates intramedullary change.

Indications for Surgery

1. Multisegmental cervical spondylosis with a narrow canal

2. OPLL with continuous or mixed type

3. Developmental spinal canal stenosis

4. JOA score below 13/17.

Contraindications

1. Kyphotic deformity

2. Soft disc herniation

3. One- or two-level spondylosis without developmental canal stenosis

Advantages of Spinal Process Median Splitting Laminoplasty for Cervical Myelopathy

1. Short operating time using threaded saw (T-saw) and hydroxyapatite (HA) spacer

2. Full expansion of the spinal canal

3. Preventing postoperative kyphotic change and the formation of peridural scar tissue

4. Nerve root decompression with partial facetectomy

5. Spinal stability with bone graft

Disadvantages

1. Decreasing range of motion (ROM) of the cervical spine

2. Postoperative stiffness in the neck and the interscapular region

Procedure for Spinal Process Median Splitting with HA Spacers

Laminoplasty Levels

Extent of laminoplasty is usually from C3 to C7. If there is a narrow canal at the C2 level, this level should be included. If an instability is recognized preoperatively, bone grafting for stabilization should be used instead of an HA spacer.

1. Positioning: The patient is intubated and placed in the prone position on a four-point supporting frame. Mayfield’s pin holder is safe and useful for maintaining cervical alignment in slight extension. In cases of a second operation, the neutral position is better than the extension position so that an airtome can be used instead of a T-saw for splitting of the spinous process. Cervical alignment should be reconfirmed by xray before making the skin incision.

2. Skin incision: The midline incision is usually made from the C2 spinous process to the T1 spinous process. The ligament nuchae is dissected in midline.

Only gold members can continue reading. Log In or Register to continue