How Common are Herniated Disks in Children?

Patient Presentation
A 15-year-old female came to clinic with a history of lumbar pain for 2 weeks. She was a softball infielder and thought that the pain began after she had increased her training and had to slide into bases over a several day period. She said it was “just always there” and she described 4-6/10 for intensity. No specific movements or position made it worse or better. She had tried using heat and ice, massage and some increased rest at night but she still did not stop playing. Intermittent ibuprofen provided some relief. She denied any specific radiation of the pain into her legs, or bowel or bladder problems. The past medical history was positive for a sprained ankle. The family history was positive for a maternal grandmother with a herniated disk as an older woman. The review of systems was negative.

The pertinent physical exam showed a healthy female with normal growth parameters and vital signs. Her spine appeared normal. She had generalized stiffness and decreased flexibility in the lumbar spine. No specific flexion, extension, lateral movement or rotational movement of the spine increased the pain or elicited radicular symptoms. She did have a positive straight leg test on both sides but her hamstrings were also tight. She had no specific sensory changes in the lower extremities.

The diagnosis of low back pain that was most likely soft tissue in origin was made. Because it had not improved, and radiologic evaluation using plain radiographs were ordered and were normal. The patient’s clinical course showed she began rehabilitation with physical therapy. Unfortunately after another 2 weeks she continued to have pain and was referred to a sports medicine specialist. Magnetic resonance imaging at that time showed a protrusion of the L4-L5 disk. She was instructed to use high dose oral anti-inflammatory medication, rest and do monitored rehabilitation with the physical therapist. After another 2 weeks with some but not significant improvement she had a steroid injection after which she had pain relief. She continued to do her rehabilitation and slowly over the next 8 weeks she returned to her normal routine.

Discussion
Intervertebral disk herniation occurs at the same locations in pediatric patients as adults with L4-L5 and L5-S1 being the most common. Patients often (30-60% for lumbar disk patients) have a direct trauma or sports related injury that is identified before the onset of pain. There is also a group of morbidly obese patients who probably have degenerative disease. In adults and children, lumbar disk herniation is also seen with repetitive or excessive axial loading, poor conditioning, decreased range of motion and history of prior back injury. Disk herniation is caused by vertebral motion that causes increased intradisk pressure including axial compression, lumbar flexion and/or rotation.

Presentation is usually acute low back pain and/or lower extremity radiculopathy. Pediatric patients often will have less specific descriptions of the pain or complain of other symptoms which leads to longer duration before diagnosis. Disk disease is also uncommon therefore other common causes of back pain are usually sought first. A differential diagnosis of back pain can be found here. “Less than 10% of children presenting with low back pain have disk herniation as the cause, and less than half of those children require surgery.” Causes of back pain that are associated with back extension on physical examination include spondylolysis or spondylolisthesis, and slipped vertebral epiphysis. Problems associated with back flexion on physical examination include disk herniation, apophyseal injuries of the vertebral end plates, Scheuermann disease and Schmorl nodes.

Most patients with a herniated disk will have symptoms with a straight leg raising test and about ~33% will also have a positive crossed straight leg raising test. The straight leg test is considered positive if leg pain (not back pain) radiates below the knee. A reactive scoliosis is also common in pediatric patients with bending toward the contralateral side in an attempt to open up the affected intervertebral space and decrease pressure on the affected nerve. This scoliosis usually resolves with treatment. Patients also often present with generalized stiffness and compensatory gait abnormalities that usually improve with treatment. The bowel and bladder are usually not affected.

Bowel and/or bladder dysinnervation or other progressive neurological deficits, debilitating pain and non-relief with conservative treatment are causes for surgical intervention. Conservative treatment usually includes rest, physical therapy to improve mobilization, flexibility and strength, and anti-inflammatory medication. Pediatric patients with disk herniation f2007 unfortunately respond less well than adults to conservative treatment and are more likely to require operative treatment. This is felt to be because pediatric disks are more elastic and have a higher water content than adults who often have more dried out or degenerative disks. Because of the elasticity operative management also can be more difficult to perform. Open procedures are usually performed and not endoscopic procedures or chemonucleolysis. Surgical treatment has good short term prognosis but 20-30% of patients may require repeated surgical treatment later in life. Plain radiographs of the spine will rule out other causes of back pain such as various fractures and malalignment. Magnetic resonance imaging is the choice for disk disease as it helps to evaluate the soft tissue and neural constituents.

Learning Point
Although intervertebral disk herniation is common in adults, it is relatively uncommon in children. Of patients with disk herniation in various case series, it occurs 0.4%-15.4% in pediatric patient with ~5% being cited often. It is even more infrequent in patients < 10 years of age, but increases in the adolescent population. Gender predominance depends on the study. A positive family history has been reported as a risk factor with presumed weak connective tissue or developing degenerative changes at an earlier age being the proposed explanation.

Questions for Further Discussion
1. What spinal levels correspond to dermatomes in the anterior leg?
2. What spinal levels correspond to dermatomes in the posterior leg?
3. What are indications for referral to a sports medicine specialist?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Herniated Disk and Spine Injuries and Disorders.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

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Tsutsumi S, Yasumoto Y, Ito M. Idiopathic intervertebral disk calcification in childhood: a case report and review of literature. Childs Nerv Syst. 2011 Jul;27(7):1045-51.

Lavelle WF, Bianco A, Mason R, Betz RR, Albanese SA. Pediatric disk herniation. J Am Acad Orthop Surg. 2011 Nov;19(11):649-56.

Ho C, Chang S, Fulkerson D, Smith J. Children presenting with calcified disc herniation: a self-limiting process. J Radiol Case Rep. 2012 Oct;6(10):11-9.

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital