Diagnosis of lumbar disc herniation The herniation of lumbar discs due to trauma or degeneration and other causes and the production of symptoms and signs consistent with the herniation is called lumbar disc herniation. Lumbar disc herniation is one of the most common causes of low back pain, accounting for about 20% of low back pain; with L4/5 intervertebral disc herniation being the most common, followed by L5S1 and L3/4 intervertebral discs. Although lumbar disc herniation is common, its correct diagnosis is not easy and often leads to mistreatment due to misdiagnosis, therefore, it is necessary to discuss the diagnosis of lumbar disc herniation from the following aspects. Symptoms 1, lumbago: due to the herniated disc can stimulate the outer fibrous ring and the posterior longitudinal ligament of the sinusoidal nerve fibers, so patients with lumbar disc herniation often have lumbar back pain. Low back pain can occur before, during or after leg pain. The range of low back pain is wide, mainly in the lower lumbar or lumbosacral region, and the nature of the pain is mostly chronic dull pain, or can be acute severe pain. Its incidence in patients with lumbar disc herniation accounted for 96.5%. 2, sciatica (sciatica): the incidence of lumbar disc herniation patients accounted for 82.6%. Because lumbar disc herniation occurs in L4/5 or/and L5S1 interspace, sciatica is common. The pain is mostly radiating from the buttock, posterior-lateral thigh, posterior-lateral calf to the ankle, dorsum of the foot, toes, heel, or sole of the foot. Very few patients may experience radiating pain from below to above. Except for the central herniation which may cause bilateral sciatica or bilateral alternating sciatica, sciatica is usually unilateral. Sciatica is affected by abdominal pressure and changes in body position. Coughing, sneezing, straining to defecate when the pain aggravates; flexion, hip and knee flexion so that the volume of the spinal canal increases, the sciatic nerve relaxation and thus reduce the pain. “Walking less than a few dozen meters, cycling dozens of miles,” is the lumbar intervertebral disc herniation patients sciatica characteristics of a specific portrayal. First lumbar pain, then leg pain, and finally leg pain is heavier than lumbar pain is the main symptom characteristics of patients with lumbar disc herniation. 3, lower abdomen or thigh anterior medial pain: high lumbar disc herniation so that the L1, L2, L3 nerve root involvement can appear in the corresponding nerve distribution area of the groin or thigh anterior medial pain. L4/5 or L5S1 intervertebral disc herniation can also cause groin area, perineum, involving pain. Sinusoidal nerve 2/3 by the sympathetic nerve, 1/3 by the somatic nerve composition, L4/5, L5S1 disc herniation stimulated the sympathetic nerve fibers is also caused by the lower abdomen, anterior medial thigh, perineum pain is an explanation. 4, intermittent claudication (intermitent creep): the patient walks a certain distance after the feeling of lumbar and leg pain, numbness aggravation, take a squatting position or sitting position, the symptom is relieved or disappear, this performance is called intermittent claudication. This is called intermittent claudication. The explanation is: when walking, the obstructed venous plexus in the vertebral canal is gradually congested, which aggravates the degree of congestion and compression of the nerve root, so the symptoms are aggravated; when taking the squatting position or sitting position, the volume of the vertebral canal is enlarged, and venous reflux is smooth, so the symptoms are alleviated. 5, numbness or coldness of the affected limb: the protruding intervertebral disc tissue compresses or stimulates the proprioceptive and tactile fibers causing numbness in the distribution area of the affected nerve root. The protruding intervertebral disc tissue stimulates the paraspinal sympathetic nerve fibers or the sympathetic nerve fibers of the sinusoidal spinal nerves, which reflexively causes the contraction of the blood vessels in the lower extremities, and the patient feels that his/her limbs are cold, and this phenomenon is also called cold sciatica. 6, nerve function damage: lower limb weakness or paralysis: prominent disc compression of the nerve root is serious, too long, can cause the affected innervation muscle weakness, or even paralysis. Sphincter and sexual dysfunction: central type, huge type or free type of protruding disc, compression of cauda equina nerve, can cause cauda equina syndrome, manifested as anal and urethral sphincter and sexual dysfunction, such as constipation, dysuria or incontinence, impotence and so on. Signs and symptoms 1, forced position and abnormal gait: severe symptoms can be manifested as forced stooping and bucking position and constrained or limping gait. 2, lumbar spine shape and mobility: patients with serious symptoms of lumbar disc herniation often show changes in the shape of the lumbar spine and reduced mobility. For example, the physiological convexity of the lumbar spine becomes shallow, disappears or convex, convex to the healthy side (the protruding disc in the axillary part of the nerve root) or the affected side (the protruding disc in the shoulder part of the nerve root); lumbar anterior flexion, posterior extension, lateral flexion and rotational range is limited. Flexion to the affected side and at the same time limited backward extension are typical signs of lumbar disc herniation. 3.Pressure pain and radiating pain: when lumbar disc herniation is associated with radiculitis, there is obvious pressure pain on the affected side of the lesion of the interspinous space, and it radiates to the distribution area of the nerve. 4, muscle atrophy and muscle weakness: due to the herniated disc compression of the nerve root and pain in the affected limb dare not use force can cause muscle atrophy and muscle weakness. For example, L5 spinal nerve involvement causes bunion dorsiflexion, toe dorsiflexion and ankle dorsiflexion muscle weakness, and S1 spinal nerve involvement causes maternal flexion and ankle dorsiflexion muscle weakness. Skin sensation and tendon reflex changes: patients with lumbar intervertebral disc herniation may have superficial skin sensation loss and tendon reflex reduction or disappearance in the distribution area of the affected nerves, such as knee reflex reduction in the case of L4 nerve involvement, and Achilles tendon reflex reduction or disappearance in the case of S1 nerve involvement. 6. Straight leg raising test (Lasegue’s sign) and strengthening test (Bragard’s sign): when lumbar disc herniation involves the nerve roots and leads to radiculitis, it can be manifested as a positive straight leg raising test and strengthening test, or even a positive healthy leg raising (Fajersztajn’s sign, also known as the crossover test) and strengthening test. 7, supine abdominal test: the patient lies on his/her back, with the pillow and both heels supporting the buttocks and back, if there is radiating pain in the affected limb, it will be positive. If there is no radiating pain, let the patient keep the position of lifting the buttocks and supporting the abdomen for coughing or holding the breath until the color of the face becomes red, the emergence of radiating pain in the affected limbs is also positive. Typical lumbar disc herniation can have imaging changes. 1, X-ray film: show the indirect signs of lumbar disc herniation, such as lumbar physiological anterior convexity becomes shallow, disappears or reverse curvature, lumbar scoliosis, lumbar intervertebral space of disc herniation becomes narrow, left and right unequal width, front and back equal width, or even anterior and posterior narrowing and widening, the relative edge of the sclerosis and lipoid hyperplasia, intervertebral foramen becomes small, and Schmörl’s node, and so on. Oblique radiographs have no specific value, but lesions of the pedicle can be excluded. 2.CT: It shows the direct signs of lumbar disc herniation, such as the location, size and nature of disc protrusion (with or without calcification), fullness of lateral recess, thickening or flooding of nerve root, etc. It can be used to diagnose lumbar disc herniation. The accuracy of its diagnosis of lumbar disc herniation is 70%, and the main manifestations are: (1) The intervertebral disc protrudes posteriorly and/or laterally, and individually may protrude into the intervertebral foramen or outside the foraminal opening. (2) The lateral saphenous fossa is full and the nerve root is submerged, or the nerve root is irritated by the pressure of the protruding intervertebral disc and thickened by edema. (3) Loss of the anterior interspace of the dural sac and deformation of the dural sac by compression (Fig. 7). (4) Punctate or/and blocky high-density shadows may appear in the protruding intervertebral disc, which is a manifestation of calcification of the intervertebral disc. In order to accurately characterize the size and location of the herniated disc, a three-dimensional, two-sectional, three-directional view can be used. Sagittal plane, showing the thickness of the herniated disc. It is divided into three levels: Ⅰ level shows the level of the intervertebral disc; Ⅱ level shows the upper level of the intervertebral disc, i.e., from the level of the inferior arch notch of the previous vertebral body to the upper boundary of the intervertebral disc; Ⅲ level shows the lower level of the intervertebral disc, i.e., from the lower boundary of the intervertebral disc to the level of the superior arch notch of the next vertebral body. The left-right direction of the cross-section shows the extent (width) of the intervertebral disc protruding to the left and right. It is divided into 4 zones: zone 1 is in the middle 1/3 of the spinal canal, zone 2 is in the left or right 1/3 of the spinal canal, zone 3 is in the intervertebral canal, and zone 4 is outside the outer orifice of the intervertebral canal. Anterior-posterior orientation, showing the degree (length) of posterior herniation of the disc. It is divided into 4 domains: a domain of disc herniation is 1/4 of the sagittal diameter of the spinal canal, b domain is 1/2, c domain is 3/4, and d domain is up to 4/4. MRI: MRI is feasible when there are contradictions between clinical manifestations and CT signs, and it can reflect the imaging characteristics of multiple lumbar vertebrae and intervertebral discs in the sagittal or coronal position, which is very valuable for confirming the diagnosis of intervertebral disc herniation or ruling out other pathology such as tumors and tuberculosis, with an accuracy of up to 90%. It is valuable for confirming the diagnosis of intervertebral disc herniation or excluding other lesions such as tumor and tuberculosis, and the accuracy can reach 90%. Diagnosis 1, lumbar disc herniation diagnostic basis Diagnosis of lumbar disc herniation, symptoms, signs and imaging data must be combined together to comprehensively consider, comprehensive analysis, to ensure the consistency of the three, the consistency of the performance in the following three aspects. (1) Lateral consistency: in the vast majority of cases, the lumbar intervertebral disc protrudes on the side of the image and the side of the symptoms and signs are consistent. For example, if CT shows that the disc protrudes to the left side, the patient should feel pain in the left leg, and the examination reveals that the left straight leg raising test and strengthening test are positive. (2) Level consistency: CT shows that the level of disc protrusion (gap), the affected nerve and the complaint area and physical signs reflect the lesion nerve is consistent. (3) The degree of consistency: generally the image shows that the larger the protrusion, the more severe the clinical symptoms and signs, but this is not absolute, but also by the protrusion of the intervertebral disc and the location of the compressed nerve root relationship of the impact. 2, lumbar intervertebral disc herniation localization diagnosis (1) lumbar 1 ~ 3 intervertebral disc herniation: thoracic 12 to lumbar 3 vertebrae between the intervertebral disc protrusion is called the high lumbar intervertebral disc herniation, less common, compression of lumbar 1 ~ 3 nerve composed of the occluder nerve and the femoral nerve, due to the lumbar 1 ~ 3 spinal nerves more than their own special signs, often jointly innervate iliopsoas muscle or lumbar 4 nerves jointly innervate the femoral internal retractable muscle group and quadriceps muscle. Sensory disturbances in case of compression In case of lumbar 1 nerve compression, there is pain and numbness in the upper 1/3 diagonal band from the groin to the knee. With compression of the lumbar 2 nerve, pain and numbness in the anterior 1/3 of the mid-thigh in an oblique banded area. Pain and numbness in the lower anterior 1/3 of the thigh in an oblique banded area when the lumbar 3 nerve is compressed. Manifestations of dyskinesia occurring with compression Weakness of anterior hip flexion due to iliopsoas muscle involvement. Weakness of hip joint inward flexion from an external stand when the intramuscular group of femoral muscles innervated by the lumbar 2 to 4 spinal nerves is involved. Involvement of the femoral nerve innervating the quadriceps muscle, which is composed of the spinal nerve fibers of the lumbar 2 to 4 ganglia, is manifested as atrophy of the quadriceps muscle, weakness of knee extension, and weakness or disappearance of the knee reflex and the reflex of raising the testicles. (2) Lumbar 3-4 intervertebral disc herniation: compression of lumbar 4 nerve root, the patient has pain and numbness in the back, lumbosacral region and lateral thigh, calf and inner side of the foot. Weakness of dorsiflexion and inversion of the foot. Because the lumbar 4 nerve is involved in innervating the quadriceps muscle, there are also signs and symptoms such as weakness of the quadriceps muscle, weakness of knee extension, and weakness or disappearance of knee reflex. (3) Lumbar 4-5 intervertebral disc herniation: compression of lumbar 5 nerve root. It mainly involves the tibialis anterior muscle and extensor digitorum, often with pain in the lumbar back and lumbosacral region, and radiating pain and numbness to the thigh, posterior lateral calf to the dorsum of the foot and toes, as well as weakness of dorsal extension of the mother toe, and foot drop in severe cases. (4)Lumbar 5~sacral 1 intervertebral disc herniation: compression of sacral 1 nerve root, sensory impairment manifested as pain in the lumbar back, sacrococcygeal area, buttocks, and radiating pain and numbness to the posterior side of the thighs and calves to the bottom of the feet, and movement disorder mainly caused by the simultaneous involvement of peroneal longissimus muscle and shortissimus muscle with weakening or loss of extensor hallucis longus muscle of the feet, as well as ankle joint, foot and toe flexion weakness caused by triceps muscle involvement and weakness and loss of reflection of the Achilles tendon. Symptoms and signs such as weakening or loss of reflexes of the Achilles tendon. The above are the common symptoms and signs caused by compression of the nerve root by the lateral herniation. The central herniation can compress the nerve root 1 to 2 places below the herniated space, or even the whole cauda equina, causing pain and numbness in the lumbar region and/or both lower limbs, and in severe cases, it can lead to weakness or paralysis of bladder and rectal sphincter, resulting in symptoms such as weakness or incontinence of defecation, and signs of Achilles tendon reflex and reflex of the testes, etc. Individual male patients may also have symptoms of decreased libido and impotence. The intervertebral foraminal and extreme lateral herniation can compress the nerve roots in the same or even the previous interspace, thus causing the corresponding symptoms and signs. If there is only an intervertebral disc protrusion on the image, but there are no symptoms and signs consistent with the protrusion, it can only be diagnosed as lumbar disc protrusion on the image, but not clinically diagnosed as lumbar disc herniation. Differential diagnosis 1, lumbar spondylolisthesis: sciatica is mostly bilateral. In the late stage, there is often numbness in the saddle area, weakness of the lower limbs, and increased lumbar anterior protrusion. Lateral lumbar spine film shows lumbar spondylolisthesis, lumbar spine oblique film can see arch collapse. 2.Spinal tumor: lumbar and leg pain is persistent, especially at night, which may be accompanied by symptoms and signs of primary tumor. Laboratory tests mostly show increased blood sedimentation. Imaging examination shows that the vertebral body and arch root are destroyed, but the intervertebral space is not narrow. Lumbar spine tuberculosis: lumbar pain is persistent. It is often accompanied by low fever and night sweats in the afternoon, and X-ray examination shows narrowing of joint space and destruction of vertebral body. X-ray examination shows narrowing of the joint space, destruction of the vertebral body, and occasional cold and thick swelling shadow next to the lumbar spine. According to the symptoms and signs, it is not difficult to identify. 4, lumbar spinal stenosis: this disease has a history of lumbar and leg pain and intermittent claudication, easy to confuse with disc herniation, but the separation of symptoms and signs is a characteristic of this disease, that is, the symptoms are heavy, the signs are light, and lumbar spinal extension restriction is often the main sign. x-ray film shows narrowing of anterior and posterior diameters of the spinal canal. If necessary, spinal myelography or CT examination should be performed to confirm the diagnosis. 5.Lumbar myofascial pain syndrome: it is an extravertebral canal lesion with limited pressure points in the lumbar region, and the test (lumbar lordosis test) which makes the volume of the spinal canal smaller is negative.