A 12-year-old boy is brought to the office by his parents due to progressive back pain. The pain began several months ago in the central low back during sports practice. Over the last month, the pain has persisted after other activities and occasionally radiates to the patient's buttocks and legs. Neither acetaminophen nor ibuprofen has significantly improved the pain. The patient has had no fever, rash, or other joint pain. He participates in golf and competitive diving. Medical history is unremarkable. His mother and maternal aunt have rheumatoid arthritis. Temperature is 36.7 C (98 F), blood pressure is 110/65 mm Hg, pulse is 80/min, and respirations are 16/min. Physical examination reveals a palpable step-off in the lumbosacral area. The pain is reproducible with lumbar extension; lumbar flexion is painless. Straight-leg raising test is normal bilaterally. Gait is normal. Which of the following is the most likely diagnosis?

Question

A 12-year-old boy is brought to the office by his parents due to progressive back pain.  The pain began several months ago in the central low back during sports practice.  Over the last month, the pain has persisted after other activities and occasionally radiates to the patient's buttocks and legs.  Neither acetaminophen nor ibuprofen has significantly improved the pain.  The patient has had no fever, rash, or other joint pain.  He participates in golf and competitive diving.  Medical history is unremarkable.  His mother and maternal aunt have rheumatoid arthritis.  Temperature is 36.7 C (98 F), blood pressure is 110/65 mm Hg, pulse is 80/min, and respirations are 16/min.  Physical examination reveals a palpable step-off in the lumbosacral area.  The pain is reproducible with lumbar extension; lumbar flexion is painless.  Straight-leg raising test is normal bilaterally.  Gait is normal.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d5da_1975_bc81_23bf9cffbec3_MD0003_00 In adults, back pain is common and usually benign. In children, back pain is often due to benign musculoskeletal conditions or trauma, but a careful evaluation to exclude other causes should be performed. This patient's back pain, particularly with lumbar extension, and examination findings are consistent with spondylolisthesis. Spondylolysis represents pars interarticularis defects (eg, fractures) that are often due to overuse injury and can be unilateral or bilateral. Spondylolisthesis is characterized by forward slip of a vertebral body (usually L5) and develops in patients in spondylolysis who have bilateral defects. It is most common during adolescent (age 10-19) growth spurts due to increased physiologic lumbar lordosis (exposing L5 vertebra) and decreased bone mineralization. Athletes with repetitive back extension and rotation (eg, gymnasts, divers) are at greatest risk. Spondylolysis lumbar lordosis In addition to progressive low back pain, the shifted vertebra can also impinge on the spinal cord and cause radiculopathy (eg, radiating pain, numbness, weakness) in patients with spondylolisthesis. A palpable step-off at the area of vertebral displacement is characteristic on examination. Spondylolisthesis is typically detected on lumbar radiographs, and symptoms resolve with conservative management (eg, limited activity, physical therapy, analgesics) in most cases. Persistent pain, progressive vertebral displacement, or neurologic abnormalities (eg, weakness, incontinence) require surgical evaluation. (Choice A) Ankylosing spondylitis is an inflammatory arthritis that can present with vertebral or sacroiliac joint pain and stiffness that is worse at night and improves with activity. Sacroiliac joint tenderness and limited lumbar flexion are common examination findings. (Choice B) Epidural abscess typically causes fever and severe localized back pain and tenderness, not seen in this patient. (Choices C and D) Lumbar disc herniation and lumbosacral strain are common causes of back pain in adults. Pain related to a strain is usually nonspecific whereas pain with disc herniation typically worsens with flexion (rather than extension) and can be elicited with straight-leg raising. Neither etiology causes a step-off on examination. (Choice E) Vertebral metastases may present with insidious back pain that is often worse at night. Systemic features (eg, fever, weight loss) and focal tenderness over the metastases would be expected. (Choice G) Vertebral compression fracture is uncommon in healthy children without osteoporosis. In addition, pain related to a compression fracture typically worsens with sitting and standing. Point tenderness, rather than a palpable step-off, is usually present on examination. Educational objective: Spondylolisthesis is the anterior slippage of a vertebral body due to bilateral defects of the pars interarticularis (spondylolysis). Classic presentation is an adolescent with low back pain exacerbated by lumbar extension. References: Spondylolysis and spondylolisthesis: a review of the literature. (http://www.ncbi.nlm.nih.gov/pubmed/29881164)

A 12-Year-Old Boy Is Brought to the Office by His