Introduction 

Laminoplasty, a surgical procedure in the field of orthopaedics and neurosurgery, involves the strategic modification of the lamina, a bony arch on the vertebral arch's posterior side. This procedure is designed to address specific spinal conditions and provide therapeutic interventions.¹ A group of Japanese orthopaedic surgeons first developed laminoplasty as a surgery between 1970 and 1980.² Laminoplasty has developed throughout the years, and these updates have created better solutions for current patients. 

Purpose and indications

The purpose of laminoplasty is to relieve the pressure exerted on nerves by deformed spines. Our spine, or the vertebral column, is the main support structure of our body. 

The vertebral column is formed by bones called vertebrae. The front of each vertebra bone is called the vertebral body, and the back has a projected piece of bone called the spinous process, and two pieces of flat bone called lamina on the left and right side of the spinous process, reaching the front, which form a hollow space, the spinal canal.³ The spinal cord, a vital part of our central nervous system, runs along the spinal canal. The spinal cord contains all the spinal nerves, and branches from the main cord at each vertebral level to reach other parts of the body. There is an intervertebral disc between each vertebra which acts like a cushion. The spine is divided into three areas: the vertebral level (C1-C7) around the neck, is called the cervical spine, the vertebral level (T1-T12) around the chest, is called the thoracic spine, and the vertebral level around the waist(L1-L5) is called the lumbar spine.³ 

Laminoplasty is used to treat cervical spondylotic myelopathy when the cervical spinal cord is compressed due to degenerative narrowing of the patent canal, or cervical disc herniation. Other degenerative and spondylotic changes like joint osteophytes, and loss of the integrity of the intervertebral disc, also increase the chance of having cervical spondylotic myelopathy. The lateral corticospinal tracts and the spinocerebellar tracts in the cervical spinal cord are responsible for limb movement controls and proprioception. When pressure is exerted on these lateral corticospinal tracts and spinocerebellar tracts, the motor function of the upper limbs is affected, which causes patients to experience clumsiness. Radiating neck pain and stiffness is another common symptom. 

There are different types of laminoplasty procedures, each technique having its advantages and potential complications, and the decision is often made based on the individual needs of the patient. Some of the common techniques include:⁴

Open-door laminoplasty

• This is the traditional and most commonly performed laminoplasty technique
• The surgeon cuts one side of the lamina and then swings it open like a door, creating more space in the spinal canal
• The opened lamina is typically stabilised in this position using sutures or other devices

Double-door laminoplasty

• Similar to open-door laminoplasty; both sides of the lamina are cut and hinged open, creating a "double door"
• This technique allows for a larger opening and decompression of the spinal canal

French door laminoplasty

• This is a modification of the double-door laminoplasty
• The lamina is cut into three pieces, with the middle piece acting as a hinge, resembling a French door

Laminoplasty procedure

This surgical intervention aims to alleviate pressure on the spinal cord and nerves by creating an additional space within the spinal canal. 

Before the surgery, anaesthesia is performed and neurological monitoring is prepared to provide more information about the spinal cord before and during the surgery.⁴ The surgical team placed patients into an appropriate position, with the patient on the bed facing the ground, with the bed slightly bent at the knee, and the knee protected with foam. The patient's head is held by a Mayfield head holder to prevent movement and displacement. Thumbs facing downward, the patient's hands are positioned on the side. The position is designed to expand the spinal canal slightly and prevent another compression during the surgery.¹ 

The skin is longitudinally cut from the upper neck following the midline. Deep dissection is continued while preserving surrounding muscle as much as possible. For open-door laminoplasty, an opening is created at the junction of the lamina and lateral mass, and a hinge is created on the contralateral side, while for double-door laminoplasty, the opening is created on both sides. The spinous process is then lifted to facilitate the opening of the spinal canal. After every level has been opened, plating is used to support and maintain the opening.¹

To minimise venous bleeding after surgery, the head of the bed should be greater than 45 degrees and patients should wear a cervical collar for more than 3 weeks to make sure their neck is stable. 

Risks and complications 

Like any surgical procedure, laminoplasty carries certain risks and potential adverse events. The specific complications can vary depending on factors such as the patient's overall health, the extent of the procedure, and the skill of the surgical team. 

Wound healing may be slow and some studies reported a high infection rate at surgical sites of up to 8%, but the use of topical vancomycin powder can lower the chance of infection.¹ 

Laminoplasty involves working near the spinal cord, and there is a risk of injury to the spinal cord or nerves. Although this neurologic injury is rare, this can lead to neurological deficits, including weakness, numbness, or paralysis.¹

Postoperative C5 palsy is a complication of many cerebral-related surgeries. Symptoms of C5 palsy are dysfunction of muscles in the arms and around the connection between the shoulders and the trunk.¹ Patients with C5 palsy can still recover muscle function, but in severe cases, patients need much longer to recover.⁵ A potential reason for C5 palsy is the tethering of the C5 nerve root.⁵ 

Success rates and outcomes

A prospective cohort study recorded the clinical outcome of laminoplasty in 98 patients with cervical myelopathy. The neurological outcome is measured using the Japanese Orthopaedic Association (JOA) score,⁶ which is a questionnaire to evaluate limb motor and sensory function.⁷ The 10-second grip and release test, a test recording the grip and release cycle in 10 seconds, measured hand coordination. Recovery of neurological function measured by JOA score was shown within 12 months after the laminoplasty in 80% of the patients. The scientists also found that the recovery rate of patients with symptoms for less than 1 year is higher than patients with symptoms for at least 1 year.⁶ The overall outcome of the surgery is satisfactory even though the recovery time is dependent on age and duration of the symptoms.

Comparative analysis 

Unlike laminectomy, which involves the complete removal of the lamina, laminoplasty aims to maintain spinal stability by preserving the posterior elements. No fusion, an additional procedure of joining two vertebrae that can combine with laminectomy, is required for laminoplasty.⁸ 

 Multilevel anterior corpectomy is another surgery for cervical spondylotic myelopathy, which involves removing a vertebral body through spinal surgery. When comparing multilevel anterior corpectomy and laminoplasty, they have similar neurological outcomes, but the latter has a significantly lower complication rate.⁸

However, laminoplasty may not be suitable for all spinal conditions, and the choice between procedures often hinges on factors such as specific pathology, patient characteristics, and the goals of the intervention.

Advancements and future trends 

There are some additional procedures which may be performed after laminoplasty to relieve and even prevent several post-operative complications. For example, preoperative electromyographic testing can further evaluate the patient’s condition to allow the doctor to choose an appropriate surgery.⁹ C4-C5 foraminotomy, a procedure that enlarges the area around C4-C5 vertebrae to reduce compression of nerves around the C5 region, helps with C5 palsy.¹⁰ 

Researchers have made changes to open-door laminoplasty to minimise discomfort after the surgery. There are two primary ways they've worked on improving it. One involves taking extra care to protect the soft tissues and muscles involved in the procedure. The other approach centres on enhancing stability, which includes reconstructing the soft tissues. These adjustments aim to make the surgery more effective and comfortable for patients by addressing issues related to the symptoms commonly experienced post-operation.¹¹ 

For example, lift-open laminoplasty preserves the surrounding muscle because it expands the spinal canal by splitting the spinal processes in the midline from the inner side of the spinal canal without hurting the muscle.¹¹

Summary

In conclusion, laminoplasty is a spinal surgery for patients with cervical spondylotic myelopathy to create extra space for their compressed spinal nerves. Healthcare professionals should tailor their approach based on the unique demands of each case, optimising outcomes for individuals with diverse spinal conditions.