Differential Diagnosis for Low Back Pain in a 12-year-old Female

Single Most Likely Diagnosis

• Spondylolysis or Spondylolisthesis: This condition, involving a defect or fracture in the pars interarticularis of the vertebrae, is common in adolescents, especially those involved in sports that include repetitive hyperextension of the spine. The sharp pain when bending forward or walking is consistent with this diagnosis.

Other Likely Diagnoses

• Musculoskeletal Strain: Given the age and presentation, a simple musculoskeletal strain from overuse or improper lifting techniques is plausible. This would be more common in individuals who have recently increased their physical activity.
• Scheuermann's Kyphosis: Although more commonly associated with thoracic spine deformity, it can also affect the lumbar region, leading to back pain, especially with forward bending.
• Discitis or Disc Herniation: Though less common in this age group, disc issues can cause sharp pain, especially with movement.

Do Not Miss Diagnoses

• Spinal Infection (e.g., Osteomyelitis, Discitis): Infections of the spine are rare but serious conditions that require prompt diagnosis and treatment to prevent long-term damage.
• Tumor (e.g., Osteoid Osteoma, Osteoblastoma): Although rare, spinal tumors can cause night pain, pain at rest, and localized tenderness, which would be red flags in the history.
• Inflammatory Conditions (e.g., Ankylosing Spondylitis): Early onset of inflammatory back pain can be a sign of conditions like ankylosing spondylitis, especially if there's a family history or other systemic symptoms.

Rare Diagnoses

• Ehlers-Danlos Syndrome: A genetic disorder that can lead to musculoskeletal symptoms, including back pain, due to tissue fragility and hypermobility.
• Marfan Syndrome: Another genetic disorder that can affect the spine, leading to conditions like spondylolisthesis or scoliosis, which might cause back pain.
• Spinal Dysraphism: Congenital anomalies of the spine that might not be diagnosed until later in childhood, potentially causing back pain among other symptoms.

Each of these diagnoses should be considered in the context of a thorough medical history, physical examination, and potentially, diagnostic imaging or laboratory tests to determine the underlying cause of the low back pain in this 12-year-old female.