Ossification of the ligamentum flavum

　　The etiology of ossification of the ligamentum flavum is not yet clear. It is generally believed that it is closely related to many factors such as local mechanical factors, metabolic abnormalities, and family heredity. Various factors that cause abnormal increased load on the ossification site of the ligamentum flavum may cause ligament injury, and repeated injury, involvement, and reactive repair process will lead to ossification of the ligament.

　　The complications of ossification of the ligamentum flavum are mainly dysfunction of the urinary bladder sphincter, manifested as difficulty in urination or incontinence of urine; defecation function is also often low, about 3 to 5 times a week, with constipation and abdominal distension. Patients may have a feeling of a belt around the chest and abdomen, and it is easy to find sensory disturbance, abdominal wall reflexes, and cremasteric reflexes weakened or absent. Severe cases may lead to paralysis, and general daily life cannot be self-care.

　　In the early stage of ossification of the ligamentum flavum, those with a wider sagittal diameter of the vertebral canal may have no symptoms at all, but those with a developmental narrow sagittal diameter of the vertebral canal are more prone to compression signs of the spinal cord, which are manifested as:
　　1. Sensory disorders It appears earliest, such as limb pain and numbness, especially in the upper limbs and fingers. This is mainly due to the compression from the posterior side of the vertebral canal. The severity and extent are proportional to the degree of the lesion and the course of the disease, and inversely proportional to the sagittal diameter of the vertebral canal.
　　2. Motor disorders It usually appears 2 to 3 months after the former, with early symptoms such as increased muscle tension in the lower limbs, easy falls, weakness, and difficulty in holding objects. Severe cases may lead to paralysis.
　　3. Local symptoms of vertebral segments It is often not obvious, and in a few cases, there may be neck pain or chest, lumbar pain, and may be accompanied by limited movement and numbness induced or exacerbated during extension.

　　To prevent ossification of the ligamentum flavum, it is important to protect the affected joints in daily life, reduce joint load, lose weight, pay attention to rest, avoid long-term carrying heavy loads and poor posture, and use canes, walkers, and other aids. It is necessary to keep the affected joints warm, and hot packs or hot towels can be used for heat therapy. During the hot summer, it is best to avoid direct air flow from air conditioners or fans on the joints.
　　Appropriate exercise can greatly help to protect and improve joint movement, alleviate pain. Beneficial exercise is gentle movement with little impact on the joints, including swimming, walking, Tai Chi, slow running, cycling, etc.

　　Since the clinical manifestations of ossification of the ligamentum flavum are often similar to those of cervical spondylosis, cervical spinal canal stenosis, and do not have characteristic signs, diagnosis mainly relies on imaging examinations. The main examination methods are as follows:
　　1. X-ray film
　　The shadow of the ossification of the ligamentum flavum often overlaps with the vertebral body image and is difficult to distinguish. On the lateral view, there is a shadow of increased density of ossification mass on the ventral side of the vertebral plate or between the vertebral plates, the lower edge starts from the upper edge of the next vertebral plate, and the upper edge ends at the middle 1/2 of the vertebral plate. The shape is often triangular. If the ossification focus is small or difficult to identify, a tomogram can be taken for further diagnosis.
　　2. Myelography
　　Myelography shows complete or incomplete occlusion at the same ossification level, and it can be seen that the dura mater of the cervical spinal cord is compressed and displaced, further determining the degree of compression.
　　3. CT scan
　　CT scan can clearly show the mass-like ossification foci located on the ventral side of the vertebral plates of the cervical vertebrae, which protrude into the spinal canal and compress the spinal cord.

　　In addition to conventional treatment, the following aspects of diet should also be paid attention to for patients with ossification of the ligamentum flavum: 1. Eat light and nutritious food as much as possible, pay attention to dietary regularity. 2. Eat a reasonable diet according to the doctor's advice.

　　The treatment of ossification of the ligamentum flavum includes non-surgical therapy and surgical therapy. Non-surgical therapy is mainly used for patients with mild symptoms and early onset, the specific requirements and operations are basically similar to those of cervical spondylosis or thoracic and lumbar spondylosis, and will not be elaborated here.
　　For patients with spinal cord compression symptoms accompanied by surgery, and whose work and life have been affected, and for whom non-surgical therapy is ineffective, surgery should be performed as soon as possible. For those with the disease alone, posterior simple lamina excision, spinal canal formation, or posterior wall resection of the spinal canal can all achieve therapeutic effects. The specific choice of surgical method should be determined according to the condition.