Ruptured lumbar disc herniation refers to a series of clinical symptoms and signs caused by the rupture of the intervertebral disc annulus fibrosus and compression of the cauda equina and nerve roots of the corresponding segment by the nucleus pulposus tissue. Since this type of disc herniation has heavy clinical symptoms, strong surgical indications and relatively difficult treatment, understanding its clinical manifestations and imaging characteristics can help to select timely and effective treatment plans. General data From 1998,4 to 2003,12, 128 cases of lumbar disc herniation (LDH) were selected and treated surgically in our department with complete data, and 48 cases (37.5%) were confirmed to be ruptured herniations intraoperatively. Age ranged from 23 to 68 years old, with an average of 42.5 years, including 37 cases aged 30 to 50 years old, accounting for 77.1%; duration of disease ranged from 1 day to 28 years, with an average of 578 days, including 19 cases aged 1 month to 1 year, accounting for 39.6%, and 17 cases aged 1 year to 5 years, accounting for 35.4%. Main clinical symptoms and signs All patients had obvious low back pain or/and leg pain, followed by lower limb numbness and claudication, and some combined with urinary and bowel dysfunction. The common signs were limited lumbar movement, lateral bending or flattening deformity, lumbar pressure pain, positive straight leg raise test, reduced dorsal extension strength or foot drop, reduced pain sensation in the calf and dorsum of the foot or skin in the saddle area, and reduced or absent knee and Achilles tendon reflexes. Preoperatively, clinical symptoms and signs were recorded, and JOA scores were obtained. X-ray examination focused on lumbar curvature, intervertebral space changes, disc calcification, Schmorl’s nodes, osteophyte degeneration and posterior soft tissue shadow (measuring the maximum distance from the soft tissue shadow to the posterior edge of the vertebral body), etc. For those with significant lumbar pain or mild slippage of the vertebral body on X-ray, additional X-ray examinations were performed. CT scan is the focus of imaging examination, focusing on soft tissue shadow at the posterior edge of the vertebral body, deformation and displacement of the dural sac and compression or obliteration of nerve roots, as well as the combination of herniated disc tissue calcification, lateral saphenous fossa stenosis, ligamentum flavum hypertrophy and joint hypertrophy; if there are other pathological changes causing lumbar spinal canal stenosis in addition to disc herniation, they are not included in the statistics. MRI examinations focus on the signal changes of the diseased disc, the morphology of the protruding disc, the connection between the prolapsed nucleus pulposus and the prolapsed segment and its slippage in the spinal canal, and in some cases, the rupture of the annulus fibrosus can be observed. Measurement of relevant indexes using CT films Measurement of relevant data on CT films by a fixed physician. 1, nucleus protrusion rate (NPR): that is, the sagittal diameter index of the nucleus pulposus. The most obvious level with the largest disc protrusion is selected as the measurement object, and the maximum sagittal diameter of the protruding disc/the maximum sagittal diameter of the local vertebral canal at the same level×100％. 2.Exit lamina distance: the distance from the uppermost protruding level to the lowermost protruding level in the scan plane, i.e. the protruding lamina distance of the protrusion, which reflects the ectopic situation of the nucleus pulposus. 3.Disc protrusion angle: taking the apex of the protruding disc as the base point, the angle between the two sides of the protrusion, the measurement requires the posterior edge of the disc to be clear and the dural sac to be distinguished. Statistical processing The percentage of each symptom, sign and imaging sign in the total sample size was calculated. t-test for the mean and standard deviation of the JOA score was calculated, and t-test for the mean of the randomized design data was used for off statistical analysis. The correlation coefficient test was performed by t-test. Results In terms of clinical symptoms and signs, the JOA score was 18.50±3.65 in patients with non-ruptured-LDH and 12.27±2.94 in patients with ruptured-LDH, with a significant difference between the two (P<0.01). Most of the patients with ruptured-LDH had significant lower limb pain and were prone to complications of urinary and fecal dysfunction, while the detection rate of signs such as forced posture, scoliosis and altered tendon reflexes was relatively high; while numbness in the dorsum of the lower leg was more common in patients with non-ruptured-LDH. In addition, when comparing the straight leg elevation test as a special examination, the leg elevation angle of ruptured-LDH was significantly reduced, with nearly 80% of those less than 50o, of which more than 1/3 were less than 20o. Imaging characteristics. Among the CT signs, protruding disc morphology, size, ectopic and protrusion angle are of diagnostic value, and among them, nucleus pulposus ectopic and NPR ≥ 40% signs are more frequent in ruptured LDH. The diagnostic significance of these signs was better than that of CT for disc morphology, while the diagnostic agreement rate for nucleus pulposus ectasia was similar to that of CT. The NPR of non-ruptured-LDH patients accounted for 90% of the patients with NPR below 50%, while the NPR of ruptured-LDH patients accounted for 72.9 of the patients with NPR above 40%. In non-ruptured-LDH, r=-0.43, the hypothesis test of correlation coefficient suggested no significant correlation between JOA score and NPR (P>0.05); in In ruptured-LDH, r=-0.77, the correlation coefficient hypothesis test suggested a negative correlation between NPR and JOA scores (P<0.05). Discussion In recent years, with the common use of CT and MRI and the increase of treatments, further preoperative knowledge of the pathological changes of LDH is desired. For the treatment of ruptured-LDH, most of the literature suggests that early surgery is advisable, and direct vision surgery is preferred, while nucleus pulposus aspiration and cold ablation are contraindicated, and percutaneous endoscopic surgery should be carefully chosen. In addition, it is important to look for the removal of free nucleus pulposus tissue during surgery for ruptured-LDH, and if necessary, enlarged openings, hemi-laminectomies or total laminectomies are feasible. Classification, incidence and clinical manifestations There are various methods of classifying LDH based on the location, direction, amount, degree of degeneration, relationship to nerve roots, patient age and imaging. At present, the classification methods of the International Society for the Study of the Lumbar Spine (ISSLS) and the American Academy of Orthopaedic Surgery (AAOS) are mostly used to classify lumbar disc disease into six types, namely degenerative, bulging, herniated, prolapsed posterior longitudinal ligament subluxation, prolapsed posterior longitudinal ligament posterior and free, of which the latter three belong to the ruptured type. The incidence of rupture type-LDH has been reported differently at home and abroad, with a maximum of 77.4% and a general range of 5% to 24.2%, and 37.5% in our group. We believe that the incidence of LDH is determined by a variety of conditions, and in addition to the disease itself, it is also influenced by factors such as the grade of the hospital, the geographical environment in which it is located, its influence and even human and social habits. The diagnosis of LDH should first emphasize the medical history, clinical symptoms and signs, and low back pain is a prominent symptom of LDH, with an incidence rate of 96% or more, as well as the combination of claudication, spinal deformity, restricted movement and social habits. The Japanese Orthopaedic Society's lumbar spine disorder assessment criteria (JOA) provides a more accurate response to the state of neurological function and provides an objective indicator for clinical determination of the extent of LDH. Rupture-LDH can occur at any age, but is mostly seen in young adults, most of whom have a history of recurrent episodes of low back pain, and the symptoms suddenly worsen when there is an external force or improper posture, and are not relieved by posture, bed rest or pain medication, or even cauda equina syndrome. Compared with non-ruptured-LDH, ruptured-LDH has obvious lower limb pain and numbness, claudication, and more often combined with urinary and fecal dysfunction. Therefore, when a patient complains of sudden onset of severe, unbearable low back and leg pain with a JOA score below 12, the possibility of rupture-type-LDH should be alerted. The straight leg elevation test, which is a characteristic test for LDH, also showed significant differences, with nearly 80% of those <50o in the ruptured group, with a significantly higher proportion of those <20o than in the non-ruptured group. Most authors believe that the clinical manifestations of patients are the basis for the diagnosis of ruptured-LDH, and the clinical diagnosis rate can reach 98.8%. Imaging characteristics of rupture-LDH The diagnosis of rupture-LDH mainly relies on X-ray, CT and MRI examinations, and other kinds of imaging examinations, but they are relatively little used at present. For LDH, ordinary lumbar plain films mainly observe the physiological curvature of the lumbar spine, the change of the intervertebral space, the curved soft tissue shadow at the posterior edge of the spine and the osteophytes. When the lumbar disc lesion is present, the lumbar physiological anterior convexity decreases or disappears as a secondary deformity to relieve the pain caused by nerve root compression; the change in lumbar curvature is more obvious in ruptured-LDH, with straightening of the sagittal plane curvature and even paradoxical lordosis, and scoliosis is more likely to occur in the coronal plane. It has been reported in the literature that anterior widening and posterior narrowing of the intervertebral space often suggest non-ruptured-LDH, while reduction or significant narrowing of the intervertebral space suggests ruptured-LDH, which was not confirmed in this study. In addition, the concept of "posterior margin contour sign of the lumbar intervertebral disc" (soft tissues behind the intervertebral space with a maximum protrusion of >2 mm), which is anatomically based on the fatty layer at the posterior margin of the vertebral body and reflects the posterior aspect of the lumbar intervertebral disc fibrous ring and posterior longitudinal ligament, was proposed, but statistics showed no significant difference between the posterior margin contour measurements of different types of LDH. Also, the quality of lumbar spine plain films can have a significant effect on the display rate of the posterior margin contour sign of the lumbar disc. In this data collection, cases of combined osteophytes causing spinal nerve root canal stenosis were excluded, and the focus was on the lesion and the extradural manifestations of the adjacent segment. The degeneration of the intervertebral disc causes abnormal motion between adjacent vertebral bodies and traction spurs, suggesting vertebral instability, whereas the common claw-shaped spurs are due to periosteal exfoliation at the vertebral body edge and new bone formation under the periosteum; studies have shown no significant differences in osteophytes between different types of LDH. Scanning is the best option for the diagnosis of LDH, and CT imaging can be used to determine the extent and location of the herniated nucleus pulposus. The concept of “regional localization” can determine the pathological characteristics of disc herniation from a three-dimensional perspective, but requires a relatively high level of imaging. The main CT manifestations of rupture-type-LDH are 1. blurred: the herniation is irregular in shape, uneven, and poorly demarcated from the dural sac; 2. position: on the basis of the disc plane showing the herniation, the upper or lower edge of the vertebral body shows the herniated disc shadow in the spinal canal, with a large protrusion distance; 3. protrusion: the posterior edge of the herniation exceeds 50% of the anterior and posterior diameter of the spinal canal; 4. acute angle: the posterior convex angle of the herniated nucleus pulposus, the angle between the two sides of the herniation The angle is acute, the posterior edge is still clear, and the dural sac can be distinguished. Data analysis shows that CT scan can basically show the pathological state of the lumbar intervertebral disc. After complete rupture, the tension of the fibrous ring decreases, and the nucleus pulposus becomes a limited protrusion with an acute angle on both sides, and can be displaced. The present data show that the ectopic sign of the nucleus pulposus has a high accuracy rate in determining the complete rupture of the fibrous ring; although the signs of severe protrusion, acute angle of the posterior edge of the protrusion and blurred edges are also important in the diagnosis of ruptured-LDH, their occurrence rate is low and they should be considered together with other signs. Yin et al. concluded that an NPR of ≥40% at the level of maximum protrusion and a protrusion lamina distance >13 mm can be used as a diagnostic reference for free disc herniation. MRI has a high resolution in soft tissues and can visualize the site, direction, size and shape of the herniated nucleus pulposus and its relationship with the adjacent tissues, and the degree of degeneration can be inferred from the change in signal intensity of the disc. irregularly shaped. The signal of the herniated nucleus pulposus in T1-weighted image is higher than that of the cerebrospinal fluid and lower than that of the epidural fat, with well-defined boundaries; T2-weighted image shows high or low signal, with signal intensity lower than that of the cerebrospinal fluid and higher than that of the spinal cord. Rupture-type-LDH sagittal MRI shows migration of the protruding nucleus pulposus below the intervertebral space, and the prolapsed nucleus pulposus is characteristically connected to the residual nucleus pulposus within the disc in a tilted pattern; cross-sectional view shows the degenerated disc in a triangular or semicircular shape at the posterior edge of the vertebral body, with irregular margins and sometimes visible residual channels; some of them show a low-signal band surrounding the prolapsed disc fragments. Our data show that among the MRI signs diagnosing rupture of the annulus fibrosus, the highest rate of compliance is with the nucleus pulposus ectopicus, which is similar to the CT diagnostic compliance rate, which is around 90%; the rate of appearance of the low-signal band around the disc and the edge irregularity is relatively low, but it has diagnostic significance and is significantly higher than that of the unruptured-LDH. Correlation between JOA score and NPR in lumbar disc herniation Previous literature has more often discussed intervertebral disc from the perspective of disc morphopathology to explore the relationship between herniated discs and low back pain, and the quantitative index to measure disc herniation has some clinical utility. Most of the current CT or MRI workstations have the function of area measurement, but the specific clinical operation is complicated and the error is large; moreover, the area of herniated disc or spinal canal is the absolute value of the sample, ignoring the individual differences, so the comparability is poor. The disc herniation measurement index is objective and reliable as a quantitative index to measure disc herniation, and it is convenient and simple, and has a certain correlation with the judgment of the disease. Our data showed that there was a significant correlation between NPR and JOA scores in patients with ruptured-LDH, and significant disc herniation often suggested more severe back and leg pain symptoms; while the correlation between NPR and JOA scores in patients with non-ruptured-LDH was not significant. Analysis of the reasons for the correlation differences: 1, type-LDH disc herniation is mostly obvious, and most of them are central or paracentral, so the measurement error of NPR is small and reproducible; while in non-ruptured-LDH, the size, direction and location of the herniated disc vary greatly, and the measurement error of NPR is large. In non-ruptured-LDH, the relationship between the compressor and the nerve root and dural sac also differs greatly, for example, sometimes a smaller protrusion closely related to the nerve root can cause significant leg pain.