Degenerative ligamentum flavum hypertrophy

　　The etiology or pathogenesis of ligamentum flavum hypertrophy is not yet clear and may be related to factors such as chronic degeneration, trauma, inflammation, and metabolic disorders. During lumbar degenerative changes, the stress on the ligamentum flavum is abnormally high, and its elastic fibers may degenerate or break. The long-term process of injury and repair necessarily leads to fibrosis of the ligamentum flavum, eventually resulting in calcification of the ligamentum flavum.

　　If degenerative ligamentum flavum hypertrophy is not treated in time, further progression of the disease may lead to serious consequences such as irregular nosebleeds, decreased vision, facial paralysis, or upper limb muscle atrophy. The ultimate result of degenerative ligamentum flavum hypertrophy is the narrowing of the spinal canal, especially the initial narrowing caused by the lateral recess, leading to compression of the cauda equina and symptoms of nerve root compression. The elastic fibers of the degenerated and hypertrophied ligamentum flavum decrease, and the compensatory increase in collagen fibers, disordered fiber arrangement, and more obvious degeneration and calcification occur. Moreover, the significant increase in collagen content is the main cause of ligamentum flavum hypertrophy.

　　Symptoms of degenerative ligamentum flavum hypertrophy include spinal nerve compression, intermittent lameness, fear of forward flexion of the neck, fear of extension, insomnia, hand numbness, dizziness, lower back pain, vomiting, and other symptoms. Degenerative ligamentum flavum hypertrophy often occurs in the elderly, with a long course of disease and may have an acute exacerbation process. It often occurs between the L4 and L5 vertebral plates, compressing the cauda equina and nerve roots. The nerve roots can be affected bilaterally or unilaterally. Clinical symptoms are similar to those of lumbar spinal stenosis. It is often characterized by lower back pain, which may alleviate or disappear after rest, and may have neurogenic intermittent claudication.

　　The main prevention of degenerative ligamentum flavum hypertrophy is to encourage young and middle-aged people to strengthen physical exercise to delay the process of spinal degeneration. The elderly should also engage in appropriate physical exercise and strengthen the prevention and treatment of osteoporosis, which is very beneficial for delaying the progression of degenerative ligamentum flavum hypertrophy.

　　The main examinations for degenerative ligamentum flavum hypertrophy include nuclear magnetic resonance imaging (MRI) of the spine, lumbar MRI examination, straight leg raising test, ankle reflex, knee reflex, etc. This disease is often characterized by severe symptoms and mild signs. The paravertebral tenderness of the lesion segment is obvious, the lumbar extension test is positive, which is an important sign of the disease, and the straight leg raising test is often negative. Patients with a longer course of disease may have abnormal sensation and muscle strength. When the lesion is located at the L3-4 interspace, the L4 nerve root is compressed, the anterior side of the calf is numb, the quadriceps muscle strength is decreased, and the knee reflex is weakened; when the lesion is located at the L4-5 interspace, the lateral side of the calf or including the plantar side of the big toe and the back of the foot is numb, occasional foot drop may occur, and the tendon reflex is generally normal; when the L5-S1 interspace is involved, the posterior lateral side of the calf and including the lateral three toes of the foot and the back of the foot are numb, and the ankle reflex is generally weakened or absent.

　　Patients with degenerative ligamentum flavum hypertrophy should pay attention to dietary regularity, and mainly consume light food. They can consume more high-fiber foods and fresh vegetables and fruits, including proteins, sugars, fats, vitamins, trace elements, and dietary fibers, which are essential nutrients. A balanced diet with a variety of food types can fully play the complementary role of nutrients between foods and alleviate the symptoms of the disease.

　　The treatment of degenerative ligamentum flavum hypertrophy is basically the same as that of lumbar spinal stenosis, the principle is that the mild cases can be treated with massage, physical therapy, traction, and oral anti-inflammatory analgesics, etc., and the severe cases require the implementation of lateral posterior approach spinal canal decompression surgery.