LDH is a common lumbar lesion, which could lead to low back pain and lower extremity radicular pain [5, 6]. It is prevalent in older people, but extremely rare in adolescents. According to previous reports, the incidence of LDH in pediatric and adolescent populations varied from 1 % to 5 % in those who were 20 years old or younger [7–9]. The pathogenesis is unclear in children and adolescents, but trauma, genetics and dysfunctional biomechanical conditions are likely contributory . In childhood, the elasticity of the fibrocartilaginous ring of the intervertebral disc is better, and the well-hydrated-like nucleus pulposus also has the effect of mitigating impact. Therefore, the intervertebral disc in childhood has strong compression resistance and less calcification, and the damage of the intervertebral disc is mostly cartilage plate, and the fibrocartilaginous ring rarely ruptured . In the past, it was thought that intervertebral disc degeneration would not occur before the age of 20, but recent studies have shown that intervertebral disc degeneration can occur before the age of 10 .
The symptoms of LDH in children are mostly atypical. In this case, the main manifestation of the child was discogenic pain caused by nerve root compression, and there were left limb weakness and progressive aggravation of symptoms. At present, there are few reports and insufficient understanding of LDH in children in China, and it is often misdiagnosed as lumbar sprain and rheumatic myocarditis in children . Since the application of computed tomography (CT) and MRI imaging examinations, the accuracy of diagnosis has been improved. LDH in children does not often have the common signs and symptoms of adult LDH. It’s typical symptoms and signs include low back pain, limited flexion, abnormal gait and limited straight leg elevation. And it is worth noting that the pain is not obvious, neurological examination is rarely found positive. With the advantage of high resolution, MRI has become the most useful tool in diagnosing lumbar lesions .
Considering that adolescent spine is in the stage of growth and development and the intervertebral disc are not yet mature, most scholars believe that surgical treatment has large trauma, many complications and postoperative recurrence, so non-surgical treatment is advocated . However, some scholars believe that degenerative changes have not occurred in adolescent intervertebral discs. Most children with endplate rupture of cartilage and local epiphyseal ring penetrate into the spinal canal together, and the protrusion often contains cartilage and bone components. Due to the small size and tension plasticity of the protrusion, early surgical treatment is advocated. In this case, we believed that the child had initially adopted non-surgical treatment, but after a period of conservative treatment, it was ineffective, and the left lower limb had sensory, muscle strength, and reflex changes. At the same time, the MRI examination results suggested that the nucleus pulposus was to compress the dura or nerve root. Based on this situation, we considered that surgery should be performed in time to prevent the prolonged conservative time from aggravating the neurological damage of children.
In the selection of surgical types, there are many controversies about the surgical methods of LDH in children [1,3,4,16−18]. Some scholars suggested that the intervertebral disc tissue should be removed as little as possible, as long as the purpose of nerve root decompression was achieved. Some scholars believe that the degenerative nucleus pulposus and the ruptured posterior annulus fibrosus should be completely removed, and the internal annulus fibrosus should be retained as much as possible, which is conducive to the regeneration of intervertebral disc and helps to prevent the recurrence of intervertebral disc herniation. In recent years, endoscopic surgery such as discoscope and intervertebral foramen mirror has been carried out through muscle expansion approach, which reduces the iatrogenic soft tissue injury caused by conventional surgery and reduces the probability of postoperative chronic lumbar pain. The use of endoscopic instruments to remove the compressed nerve intervertebral disc has achieved good clinical effect, which is equivalent to the clinical effect of traditional surgery. The postoperative recovery is fast and the complications are few, and there is no significant adverse effect on spinal stability. However, due to the limitation of endoscopic instruments, it is not suitable to use micro high-speed grinding drill, Kerrison bone biting forceps and other instruments during the operation, and the nerve decompression for some severe spinal stenosis is not sufficient. For children with endplate rupture of cartilage and local epiphysis ring, it is more likely to penetrate into the spinal canal, and the decompression effect of minimally invasive endoscopic surgery alone may not be satisfactory. Therefore, in this case, we adopted minimally invasive combined with microscopic laminectomy, which not only retained the articular process joints, spinous processes and interspinous ligaments, but also well revealed the satisfactory surgical vision of the spinal canal combined with microscope. The free nucleus pulposus and ruptured annulus fibrosus could be completely removed, and the epiphyseal tissue that penetrated into the spinal canal could be resected together, so as to completely relieve the pressure on nerve roots and dura mater, and avoid the occurrence of lumbar spinal stenosis.
In this case, combined with the symptoms, signs and imaging data of children, the diagnosis was more clearly, and the symptoms did not improve and showed an aggravating trend during hospitalization. Therefore, surgical treatment was selected. For the selection of specific surgical procedures, the minimally invasive high-definition microscope with small influence on the later life of the child was selected to assist the operation under small channels, and the waist circumference was fixed after operation to increase the stability of the lumbar spine. According to the current follow-up, the short-term and long-term recovery of children are ideal.