According to foreign reports, the clinical manifestations of lumbar disc herniation in adolescents under 21 years old are diverse and atypical, symptoms and neurological signs are not exactly the same, and the diagnosis and treatment are controversial and less reported [1]. From January 2000 to January 2006, a total of 1862 cases of lumbar disc herniation were admitted to our hospital, of which 39 cases were adolescents within 21 years of age, accounting for 2.1%. 33 cases were treated with minimally invasive discoscopic medullary excision (Microinvasive Endoscopic Discectomy (MED)), 4 cases were treated non-surgically, and 2 cases were treated with open-window nucleus pulposus excision. Four cases were treated non-operatively and two cases were treated with laminectomy, which achieved good results. This article summarizes the characteristics of adolescent lumbar disc herniation and discusses the choice of treatment. 1, Data and methods 1, 1 General information 39 cases of lumbar disc herniation diagnosed by physical examination, CT and/or MRI, 36 male, 3 female, age 12~21 years old, average 17, 8 years old. Duration of the disease ranged from 20 days to 2 years, average 5 months; 20 cases had a clear history of trauma; 23 cases had received non-operative treatment for a period of 7 days to 3 months; 16 cases had their first episode, of which 4 cases were operated directly within 2 weeks after the onset of the disease. Social activities: 6 cases were fighters, 2 cases were athletes, and the remaining 31 cases were students or rural youths. 1,2 Clinical manifestations All cases had varying degrees of lumbar and leg pain or lower limb claudication. 37 cases were accompanied by calf pain, and 10 cases had numbness in the calf or foot. There were 14 cases of paravertebral or spinous process pressure and pain, 9 cases of compensatory lumbar scoliosis, 19 cases of lumbar muscle spasm, 19 cases of significant limitation of activity, 17 cases of radiating pain in the lower limbs, 21 cases of significant reduction of dorsal extensor strength, 25 cases of hyperalgesia of the lower part of the lower leg and dorsalis pedis and plantaris, 16 cases of Achilles tendon reflex hypalgesia, and 34 positive cases of straight-leg elevation test. 1 case of quadriceps and calf muscle atrophy, weakening of the knee reflex, and hyperalgesia of the outer thighs. 1.3 Imaging examination X-ray lumbar spine and CT examination were performed before operation, and MRI examination was performed in 34 cases. Lumbar spine X-ray showed narrowing of the affected intervertebral space in 9 cases, lumbarization of the sacral spine in 1 case, and no other degeneration was found.CT showed single-segment disc herniation: L4/5 herniation in 22 cases, L5S1 herniation in 16 cases, and two-segment herniation in L4/5 and L5S1 in 1 case.Lateral saphenous fossa stenosis was combined with it in 3 cases, and the isthmic cleft of L5 arch was found in one case only. There was no lumbar spondylolisthesis or lumbar spine instability, and MRI showed that 39 cases had clear lumbar disc herniation with “intervertebral disc”-like changes. The type of herniation was posterolateral in 32 cases, central in 4 cases, and giant free type in 3 cases, which was combined with cartilage endplate rupture in 1 case. According to the lumbar disc herniation grading criteria improved by Dullerud [2] and Zhang Huayi [3], there were 2 cases of Ⅰº herniation, 31 cases of Ⅱº herniation, and 6 cases of Ⅲº herniation. 1,4 Inclusion and exclusion criteria 1,5 Efficacy evaluation criteria: modified Mcnab efficacy scoring method Excellent: pain disappeared, no motor dysfunction, resumption of work and activities; Good: occasional pain, disappearance of the main symptoms, muscle strength is normal, straight leg raising test (-), can be engaged in light physical work; May: symptoms have improved, but still have pain, can not work; Poor: there is a manifestation of nerve compression, further surgery is required. Poor: nerve compression, need further surgery. 1,6 Treatment: 33 cases were treated with MED. In the prone position, epidural anesthesia was applied, C-arm X-ray was used to locate the lesion segment, and a longitudinal incision of about 2.5cm was made on the affected side and downward in the middle part of the superior spinous process of the lesion segment, and the lumbar dorsal fascia was incised one by one, an expansion sleeve was inserted, and the paravertebral muscles were separated to reach the intervertebral space along the lower edge of the vertebral plate beside the spinous process, and the working channel was installed to reveal the intervertebral space and the ligamentum flavum. Stop bleeding, clean the superficial fascial tissues in the operation field, bite off the outer part of the lower edge of the vertebral plate, a small part of the inner part of the inferior articular process and part of the ligamentum flavum, reveal and use the nerve hook to draw the nerve root and dural sac to the midline, so that the venous plexus in the vertebral canal can be clearly seen, avoided, or cauterized with bipolar electrocoagulation, and cut the annulus fibrosus to remove the protruding nucleus pulposus and annulus fibrosus. Hemostasis was performed, the incision was flushed, and a rubber strip was left to drain the incision and close the incision. In 14 cases, the annulus fibrosus was ruptured, the nucleus pulposus was dislodged into the spinal canal, and the cartilage plate was ruptured in 1 case. In 2 cases, due to the combination of lumbar spinal stenosis or lateral fossa stenosis, open laminectomy was performed, and in 4 cases, due to the initial onset of the disease, family members were reluctant to operate due to the risk of surgery, and the patients were treated with conservative treatment, including oral non-steroidal anti-inflammatory drugs, dexamethasone 5-10mg + 20% mannitol, rapid sedation, 2/d, bed rest, intermittent pelvic traction, local massage, physiotherapy, etc. The patients were treated with anti-inflammatory drugs, anti-static drugs, and local massage. 1,7 Postoperative treatment Routine antibiotics to prevent infection, oral non-steroidal anti-inflammatory drugs, short-term application of dexamethasone 5-10mg + 20% mannitol, rapid static drip, 2 / d, the second postoperative day to remove the drainage. Straight leg raising exercise was performed on the 1st postoperative day, walking out of bed under the protection of lumbar girdle and lumbar dorsal muscle exercise were performed in the 1st postoperative week, and the stitches were removed after 14 d. The lumbar dorsal muscle exercise was gradually strengthened after 3 weeks. The efficacy was assessed by modified Mcnab efficacy scoring method, and postoperative outpatient follow-up ranged from 8 months to 5 years and 2 months, with an average of 39, 2 months. 2, Results: 33 cases were treated by MED, with a mean operation time of 58, 5 minutes, intraoperative bleeding of 72, 6 ml, and no intraoperative complications. All cases were followed up for an average of 39, 2 months, efficacy: excellent 22 cases, good 14 cases, poor 3 cases, overall follow-up satisfaction rate of 92, 3% (36/39).MED treated 33 cases. The satisfaction rate of the most recent postoperative follow-up was 90,9% (30/33), and the patient’s recognition of MED treatment was 93,9% (31/33); complications: lumbar discitis in one case, with good results after anterior interbody fusion. In one case, the free nucleus pulposus was missed during the operation, resulting in postoperative symptoms of lumbar and leg pain, which were not relieved, and the symptoms disappeared after the open plate nucleus pulposus removal within one week; in one case, the symptoms of lumbar and leg pain recurred 4 months after the operation, and no obvious secondary lumbar spinal stenosis or nerve root compression was found in the CT and MRI, and the symptoms disappeared after conservative treatment for one month. No complications such as nerve root injury, cerebrospinal fluid leakage, or incision infection occurred. Four cases of conservative treatment and two cases of laminectomy with open nucleus pulposus had good results. No recurrence cases were found in the follow-up of this group. 3, Discussion 3, 1 Characteristics of lumbar disc herniation in adolescents 3, 1, 1 Males account for the vast majority of adolescents Lumbar disc herniation is clinically rare, and the incidence reported in the literature varies greatly, accounting for about 0, 5% to 3% of all lumbar disc herniation [4]. Shen Yong et al. reported 34 cases of lumbar disc herniation under the age of 20, accounting for about 1,3% of 2580 cases [1]. Yu Zesheng et al. reported that lumbar disc herniation in adolescents accounted for 2,3% of all cases, with significantly more males than females [6]. In our group, there were 39 cases of lumbar disc herniation in adolescents under 21 years of age, accounting for 2,1% of all cases in the same period, of which 36 were male and 3 were female, with a male/female ratio of 12:1, which was even more disparate when compared with other domestic and international reports [4,5,6]. 3,1,2 Trauma is the main etiology The occurrence of lumbar disc herniation in adolescents may be related to premature degeneration of the intervertebral discs, trauma, structural abnormalities of the lumbar vertebrae, and heredity [1,7]. Literature has reported that the etiology of trauma accounts for 30% to 70% of cases [1,8].Durham et al [4] and Baba et al [9] concluded that more than 72% of lumbar disc herniations in adolescents under 21 years of age develop after trauma. Yu Zesheng et al. reported that the onset of lumbar disc herniation in adolescents was clearly related to trauma in 47,6% of cases, and imaging showed epiphyseal dissections directly related to trauma in 14,3% of cases. Shen Yong et al [1] reported 20 cases of adolescent lumbar intervertebral disc herniation with a clear history of trauma, accounting for 65% of the cases, no congenital or developmental spinal deformity was found, and the rest of them were ruptured except for 2 cases of intact annulus fibrosus, of which the nucleus pulposus passed through ruptured annulus fibrosus and posterior longitudinal ligament to enter into the epidural cavity in 9 cases. This indicated that the external force was sufficient to rupture the fibrous ring which had not yet degenerated. Only one case of sacral lumbarization and one case of lumbar 5 isthmus fracture were found in 39 cases in this group, the latter having a history of multiple traumas. Soldiers, athletes, students, rural youth and other sports easily injured accounted for 32 cases, before the onset of no history of lumbar pain or leg pain, 20 cases in the onset of a clear trauma, traumatic etiology accounted for 51,3%. This indicates that trauma is the main cause of lumbar disc herniation in adolescents, and no clear correlation was found between genetic factors and lumbar disc herniation in adolescents. However, it is believed that the intervertebral disc is not the weakest point of the vertebral body-disc complex, and simple trauma does not make the intact disc protrude, and some kind of defects may exist before trauma causes disc herniation [1,7]. 3,1,3 Symptoms and signs are obvious and not significantly different from those of adults The literature reports a wide variation in the clinical presentation of lumbar disc herniation in adolescents under 21 years of age [1,5,7]. Lumbar pain is more common and more pronounced in adolescents with lumbar disc herniation compared with adult patients, which may be related to lower pain tolerance in adolescents. Most of the patients in this group had severe low back pain and were reluctant to move their lower limbs, including one case with a disease duration of 7 months, secondary quadriceps and calf muscle atrophy, and diminished knee reflexes. According to Silver et al, the clinical manifestations of disc herniation in adolescents under 21 years of age are atypical, with fewer manifestations of nerve root damage, and symptoms are obvious while neurological signs are rare [1]. However, Shen Yong et al. reported that all 34 cases had sciatica, 28 cases had low back pain, 22 cases had paravertebral pressure and radiating pain, 17 cases had compensatory scoliosis, all patients had a positive straight leg raising test, and other signs were similar to those of adults. Symptoms and signs were obvious in 39 cases in this group, and there was no obvious difference with adults. 3,2 Treatment The treatment of adolescent lumbar disc herniation is debated, and most scholars now advocate that the treatment principle is similar to that of adults [5,8]. Teenage lumbar disc herniation is often related to trauma, most of them are ruptured free type; often accompanied by large nucleus pulposus, annulus fibrosus or cartilage plate rupture, and even fracture of posterior vertebral body margin, it is difficult to decompression of non-surgical treatment; the quality of life is poor, easy to recur; the nerve root compression is not easy to recover the function of the time is too long [9]; the adolescents are very active, and the person and his family are eagerly requesting to relieve the symptom as soon as possible, and they are worried about the impact of taking time off from school or conservative treatment on the employment, so it is difficult to implement formal conservative treatment. It is difficult to implement formal conservative treatment; surgical treatment can allow patients to return to study or training as soon as possible [10]; the vast majority of reports of its surgical excellence rate of more than 90%, and after long-term conservative treatment, the success rate of surgery will be reduced [5,6,8], so it should be timely surgical treatment. However, some people believe that adolescent lumbar disc herniation should be treated conservatively. The nucleus pulposus of adolescent intervertebral discs is peptoid, with more water and greater elasticity, and the protruding nucleus pulposus can be reset by bed rest or pelvic lumbar traction and other treatments [11]; some people believe that the long-term efficacy of surgery is still uncertain, with more complications, and the possibility of postoperative recurrence, which may be related to the fact that adolescents’ vertebral bodies and intervertebral discs have not yet matured and their activities are greater. Yu Zesheng et al. advocated conservative treatment first, and surgery should try to preserve the bony structures to avoid affecting the development and stability of the lumbar spine. In our opinion, trauma or violence is the main cause of lumbar disc herniation in adolescents, and the fibrous annulus has been ruptured largely or completely, and has lost its elasticity and retraction effect, so the effect of conservative treatment is limited. Non-surgical treatment can be considered for those with less severe low back and leg pain, no obvious nerve damage, and imaging showing non-massive herniation or rupture of the annulus fibrosus. For those with more severe symptoms, long-term conservative treatment will make the nerve damage less likely to recover [5]. When conservative treatment is ineffective after a maximum of 3 months, timely surgical treatment should be performed. Those with large herniation or free-type herniation and ruptured fiber ring should not be treated conservatively and should be operated as early as possible. Of the 39 cases in our group, 23 cases with CT grading of IIº or above had been treated conservatively for more than 3 months with poor results, and the symptoms were relieved after surgical treatment, while 2 cases of Iº herniation had good results with conservative treatment. Adolescent lumbar disc herniation was dominated by simple disc herniation, with more posterior-lateral type herniation and less central type, and the herniated nucleus pulposus adhered to the nerve root or the dural sac less; the combination of lateral saphenous fossa stenosis, spinal stenosis, lumbar instability, lumbar spondylolisthesis, or isthmic fracture was rare. Fibrous ring rupture is common; surgical treatment has a high rate of excellence in the near and long term [5,6], therefore, MED is the treatment of choice. Open nucleus pulposus removal with a laminar opening is appropriate, and hemilaminectomy is usually not necessary. In our group, 33 cases underwent MED treatment, 2 cases with combined lumbar canal stenosis and lateral saphenous fossa stenosis underwent open plate nucleus pulposus removal without lumbar fusion; 4 cases were treated conservatively and discharged with symptomatic relief. Postoperative complications: 1 case of lumbar intervertebral discitis had a good effect after anterior interbody fusion; 1 case of omission of the protruding free nucleus pulposus during the operation resulted in unrelieved postoperative symptoms, which disappeared after open plate nucleus pulposus removal; 1 case of delayed onset postoperative lumbar pain and sciatica disappeared after conservative treatment for 1 month. There were no complications such as nerve root injury, cerebrospinal fluid leakage and incision infection. There was no spinal instability or vertebral slip. The average follow-up was 39,2 months, with an excellent rate of 90,9% and a 93,9% recognition of MED treatment. 3,3 Advantages of MED treatment for adolescent lumbar disc herniation. Removal of the herniated nucleus pulposus can be performed by a variety of surgical procedures, among which microscopic minimally invasive nucleus pulposus removal [12] and MED are recognized minimally invasive surgical methods. Minimizing the damage to the stability of the spine is especially important for the growing and developing adolescent spine, and most of the adolescent lumbar disc herniations are uncomplicated, with mild lumbar degeneration, small joint hyperplasia and lateral fossa stenosis, and spinal stenosis of small degree, which are suitable for MED treatment.MED is equipped with a good illumination and image magnification system, which can clearly and accurately display the important structures, such as nerve roots, venous plexus of the spinal canal and the hard and rigid bursa, and greatly reduce the damage to the hard and rigid bursa. MED is equipped with good illumination and image magnification system, which can clearly and accurately show the important structures such as the dural sac and nerve root, greatly reducing the risk of damage to the dural sac and nerve root, and it is easier to find, protect or electrocoagulate the epidural veins to reduce bleeding. The skin incision is only 2 or 5 cm, which is less traumatizing and quicker recovery after surgery. After surgery, the patient can leave the bed at an early stage, but too much activity too early will affect the tissue repair. In view of the previous MED 3 days postoperative activities out of bed so that the residual nucleus pulposus dislodged and re-operation, 7 days postoperative incision deep hematoma has formed granulation tissue, the incision of the fibrous ring has been most of the healing, the tissue edema is significantly reduced, the incision of the superficial layer of the initial healing, it should be the appropriate time to leave the bed activities.