Cervical Laminoplasty (Open-Door and French-Door)

Indication. Symptomatic multilevel cervical cord compression — cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL) across three or more levels — in a patient who still has preserved cervical lordosis (C2-C7 Cobb angle greater than 10 degrees), minimal axial neck pain, and disease that has progressed despite conservative care. The whole rationale rests on that lordosis: once the canal is expanded, the cord drifts posteriorly 2-4 mm away from the anterior compression, without resecting it. Absolute indications

• Multilevel (3 or more levels) CSM with preserved cervical lordosis (C2-C7 Cobb greater than 10 degrees).
• OPLL with multilevel cord compression and lordosis preserved.
• Minimal pre-existing axial neck pain (VAS less than 4/10) — patients with severe axial pain are better served by fusion.
• Progressive myelopathy (Nurick grade 2 or higher, or mJOA less than 14) despite conservative management. Relative indications
• Patients who wish to preserve cervical motion and avoid fusion-related adjacent segment disease.
• OPLL with segmental or continuous type where anterior surgery would require extensive corpectomy.
• Poor anterior approach candidates (prior anterior surgery, radiation, tracheostomy, high BMI). Contraindications — absolute
• Cervical kyphosis or straight alignment (C2-C7 Cobb less than 10 degrees) — the cord cannot drift posteriorly.
• Severe axial neck pain (greater than 6/10) with facet arthropathy — laminoplasty does not address posterior column pain generators.
• Single-level disease better treated by ACDF or disc arthroplasty. Contraindications — relative
• Prior posterior surgery with extensive scarring.
• Active infection or tumour requiring resection rather than decompression.
• Severe osteoporosis increasing hinge fracture risk. The one decision that matters — which posterior/anterior strategy:

Consent specifically for C5 palsy (5-10 percent, most transient), axial neck pain (10-20 percent even with muscle preservation), hinge fracture, incomplete decompression, infection (under 2 percent), and the possible need for revision fusion. Setup. Prone on a Jackson table or in a Mayfield head holder with slight reverse Trendelenburg (15-20 degrees) to reduce venous bleeding, head neutral or in slight flexion to open the interlaminar spaces. Intraoperative neuromonitoring (MEP, SSEP, free-running EMG) is mandatory. General endotracheal anaesthesia; maintain MAP greater than 80 mmHg for cord perfusion; cell saver available for an anticipated blood loss of 200-400 mL. Loupe or microscope magnification is mandatory for trough creation.

The goal: open the posterior canal by hinging the laminae outward, letting the cord drift back 2-4 mm off the anterior compression, while preserving the posterior muscle tension band (C2 and C7 attachments) so motion and lordosis are kept. The exposure — a muscle-sparing posterior cervical approach — is the heart of the operation and is laid out in full as the first steps below (and in depth on the posterior cervical approach page).

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Fixation options. After elevating the door, choose how to hold it open:

Rehabilitation | Phase | Timing | Immobilisation | Therapy | |-------|--------|----------------|---------| | 1 | Day 0–3 | Soft collar for comfort only | Neurological checks every 2 hours for the first 24 hours (C5 palsy window); isometric neck exercises from day 1 | | 2 | Week 1–6 | Collar for 2 weeks only | Gentle active range of motion from week 2; hand therapy for myelopathy-related dexterity deficits | | 3 | Return to function | Night splint if needed | Driving at 4–6 weeks; light work 6–8 weeks; heavy manual labour or contact sports 3–6 months | Most patients return to desk work by 6-8 weeks. Full neurologic recovery is assessed at 6 and 12 months. Prolonged collar use is avoided — it increases stiffness and muscle atrophy without aiding recovery.

Relevant posterior cervical anatomy. The cervical lamina forms the posterior arch of the canal and is 3-5 mm thick at C3-C6; the C7 lamina is the largest and thickest, while the C2 lamina is short and stout and carries the semispinalis cervicis insertion. The lamina-lateral mass junction is the critical landmark for trough creation, with the facet joint lying immediately lateral. The semispinalis cervicis (inserting on C2) and the multifidus (inserting on C7 and the upper thoracic spinous processes) form the posterior tension band; their detachment leads to loss of dynamic lordosis, facet overload, and progressive kyphosis in 20-40 percent. The ligamentum flavum attaches to the lamina undersurface and must be divided at the open trough; the dentate ligaments tether the cord laterally, so excessive posterior shift stretches the C5 and C6 roots. The C5 root exits most horizontally with the shortest intradural length (about 10-12 mm), which explains its particular vulnerability to tethering during drift-back. The cord occupies 50-70 percent of the canal in severe stenosis, so a canal expansion of 8-12 mm allows 2-4 mm of posterior drift. The vertebral artery lies within the transverse foramen 1.5-2 cm lateral to the lateral mass, and the epidural venous plexus is prominent — demanding meticulous bipolar haemostasis. Key evidence. Hirabayashi (1983) described expansive open-door laminoplasty, reporting 83 percent neurologic improvement at five years in the original series; the technique remains the foundation, with modern modifications focused on muscle preservation and rigid mini-plate fixation to reduce axial pain. On motion preservation, laminoplasty retains 30-50 percent of cervical motion and avoids the fusion-related complications of pseudoarthrosis (5-15 percent) and adjacent segment disease; a meta-analysis (Yuan, 2019) found laminoplasty gave better range-of-motion preservation and fewer complications than laminectomy-fusion for multilevel CSM, with equivalent neurologic recovery. On the dominant complication, a meta-analysis (Shou, 2015) found an overall C5 palsy incidence of 5.8 percent, with OPLL and post-operative cord shift identified as the key risk factors — underpinning the modern practice of limiting opening to 8-10 mm and considering prophylactic foraminotomy in high-risk OPLL. Comparing the two techniques, Nakashima (2014) found equivalent neurologic recovery between open-door and French-door laminoplasty, with the French-door showing a slightly lower hinge fracture rate but a longer operative time.