Posterior Cervical Laminoplasty
Overview: Posterior Cervical Laminoplasty is similar to Cervical Laminectomy except that instead of removing the compressing structures they are retained. Adequate room for spinal cord is made through a hinge which is maintained with sutures or implants thus relieving the compression over the neural structures.
The technique and approach of Posterior Cervical Laminoplasty is similar to Laminectomy. Due to reports of Post Laminectomy Kyphosis- Posterior Cervical Laminoplasty may be recommended. This technique instead of removing the laminae altogether, reattaches them to one/ either side using suture/plates and screws thus providing adequate stability and alignment.
It is advised for treatment of cervical spinal stenosis and myelopathy. In myelopathy, the aim of surgery is to halt the progression of spinal injury and hence the symptoms due to compression.
Surgery is usually suggested as the last resort. Failure of medical management, biomechanical instability, deformity and severe neurological compression causing weakness are usual circumstances when surgery is advised. In very few cases causing weakness of arms/legs is an emergency procedure recommended. After a thorough discussion (understanding risks and benefits) with the surgeon, the decision for surgery is taken.
The procedure is done under general anaesthesia. A tube is inserted in the throat to help breathing during anaesthesia. Patient is placed prone (face down) on the operating table. Shaving of posterior hairline may be done pre operatively. Sometimes neuromonitoring (monitoring of nerves and spinal cord) may be done to forsee and prevent neurological damage that can happen during surgery. A posterior (back of neck) 10-15 cms incision is taken. The spinal canal is exposed after dissecting the muscles of the neck. The surgical level is confirmed under C-arm (intra operative X-ray). The bones (laminae) and soft tissues compressing the spinal cord are removed. Magnification with microscope/ loupes is recommended. The bone overlying the spinal cord (the “lamina”) is partially cut on both the right and left sides. This creates a hinge on one side of the lamina and a small opening on the other side. The lamina is then moved into the “open” position by elevating the lamina on the open side. This vastly increases the space available for the spinal cord and takes the pressure off of it. A spacer made out of bone, metal, or plastic, is usually inserted to hold the spinal canal open. The final position resembles an open door being help open with a door stop, and many surgeons refer to this technique as an “open-door” laminoplasty.
Wound is closed in layers and a drain is kept for 1-2 days to prevent haematoma formation.
After the surgery, patient may be shifted to ICU for observation or to the room depending upon the medical condition. Patient is usually made to walk on the same/ next day. Normally, 3-5 days of hospital stay is required. Once medical condition is stabilized, patient has adequate pain relief and mobilized, patient is discharged.
Patient is asked to follow up for stich removal between 2-3 weeks from surgery. A waterproof dressing may be applied in some patients so that bath can be taken. Patient is required to follow up at 6 weeks, 3 months, 6 months, 1 years and then annually after surgery for examination. Based on serial x-rays and recovery – gradual increase in activities is advised.
Specific Complications:
Since the laminae are held open as a hinge with spacer, the hinge may collapse and cause recurrence of symptoms. Similarly, the spacers (sutures, plates, screws) may become loose and cause complications.
Occasionally, one of the nerves in the neck can be stunned after surgery because of the movement that occurs when the nerve moves back to its normal location after removal of the compression. This nerve “stunning” is called a nerve palsy. This palsy can cause significant weakness, especially in the shoulder, and pain in same region. Fortunately, this palsy is most of the times temporary and gets better without any treatment.
Disclaimer: The description of procedure is how usually a surgery is done. During the procedure, based on intra operative encounters which varies from patient to patient different steps may be performed.