Ossification of the Posterior Longitudinal Ligament (OPLL) is a condition where the posterior longitudinal ligament, a band of fibers running along the back of the vertebral bodies and discs in the spine, thickens and hardens into bone. This ossification typically occurs in the cervical spine. The abnormal bone growth can narrow the spinal canal, leading to compression of the spinal cord or nerve roots. This compression can cause neurological symptoms, making surgical intervention a consideration for treatment.
Understanding Ossification of the Posterior Longitudinal Ligament
While the exact cause is not fully understood, genetic, lifestyle, and hormonal factors may play a role, with a higher prevalence observed in individuals of Asian descent, particularly men in their 50s and 60s.
Symptoms of OPLL often begin subtly, with mild pain, numbness, or tingling in the hands. As the condition progresses and the ossified ligament compresses the spinal cord, more severe symptoms can emerge, such as myelopathy. Myelopathy can manifest as difficulty with balance and walking, clumsy hands, problems with fine motor movements, and issues with bladder or bowel control. Compression of nerve roots, known as radiculopathy, can also cause pain, tingling, or numbness in the neck, shoulder, arm, or hand. Diagnosis typically involves imaging studies like X-rays, CT scans, and MRI scans, which provide detailed images of the bones and soft tissues, helping to visualize the ossified ligament and its impact on the spinal canal.
Deciding on OPLL Surgery
The decision to proceed with OPLL surgery is made after careful consideration of several factors, including the progression of neurological symptoms and the degree of spinal cord compression. While conservative treatments such as medication and physical therapy may temporarily relieve pain, OPLL often progresses over time. When there is significant pressure on the spinal cord or nerve roots, surgery becomes a necessary option to prevent further, potentially irreversible, neurological damage.
Surgical intervention is often recommended for individuals experiencing progressive neurological deficits, such as worsening weakness or balance issues, or those with significant narrowing of the spinal canal due to the ossified ligament. The failure of non-surgical management to alleviate symptoms or halt disease progression also indicates the need for surgery. The choice of surgical approach is highly individualized and is determined through a collaborative discussion between the patient and their surgeon, considering the specific characteristics of the OPLL.
Types of OPLL Surgery
Surgical strategies for OPLL involve either an anterior (front) or posterior (back) approach, each designed to decompress the spinal cord. The selection depends on the ossification’s location and extent, the number of affected spinal segments, and overall spinal alignment.
Anterior Approach
The anterior approach operates from the front of the neck to directly remove the ossified ligament. Common anterior procedures include Anterior Cervical Discectomy and Fusion (ACDF), where a damaged disc and adjacent ossified ligament are removed, and vertebrae are fused to stabilize the spine. Another anterior option is Corpectomy and Fusion, which involves removing a portion of the vertebral body and ossified ligament, followed by fusion to bridge the gap. These procedures achieve direct spinal cord decompression and can help restore the cervical spine’s natural curvature.
Posterior Approach
The posterior approach accesses the spine from the back of the neck to create more space for the spinal cord without directly removing the ossified ligament. Posterior procedures include Laminoplasty, where the lamina (the bony arch protecting the spinal canal) is cut on one side and hinged open, then held in place with small metal plates to expand the spinal canal. Laminectomy and Fusion involves the complete removal of the lamina, followed by fusion of the vertebrae with screws and rods for stability. Posterior approaches are preferred for multi-level OPLL or when there is a risk of cerebrospinal fluid leakage with an anterior approach.
Post-Surgical Recovery
Following OPLL surgery, the recovery process involves several phases aimed at healing and regaining function. Patients typically spend a few days in the hospital for post-operative care, where pain is managed and initial mobility is encouraged. During this acute phase, gentle movements and short walks are advised to promote circulation and prevent complications.
Physical therapy often starts a few weeks after surgery. Early therapy focuses on gentle stretching and exercises to improve range of motion and strengthen surrounding muscles, while adhering to specific precautions like avoiding bending, twisting, or lifting heavy objects. Many patients may wear a cervical brace for several weeks to months to support the spine and aid in fusion. The timeline for returning to daily activities varies; sedentary occupations may allow a return to work within 4 to 6 weeks, while more strenuous activities and full recovery can take 6 months to over a year as the fusion site fully heals.
Addressing Surgical Complications
While OPLL surgery aims to improve neurological function, it carries potential risks, as with any surgical procedure. General surgical complications include infection, excessive bleeding, and adverse reactions to anesthesia. These risks are managed through sterile techniques and pre-operative assessments.
Specific neurological risks include spinal cord injury, nerve damage, or a cerebrospinal fluid (CSF) leak. A CSF leak occurs if the dura, the membrane surrounding the spinal cord and nerves, is inadvertently torn during the procedure. Surgeons repair any dural tears immediately during surgery, often using sutures or patches. Post-operative monitoring for symptoms like spinal headaches or fluid collection at the incision site is important for early detection and management of a CSF leak, which may require further intervention to prevent complications like meningitis.