What is reversed cervical lordosis?

Reversed Cervical Lordosis: Definition and Clinical Significance

Reversed cervical lordosis refers to the loss of the normal forward curve (lordosis) in the cervical spine, where the curve becomes straight or even curves in the opposite direction (kyphosis). This condition can occur as a normal anatomical variant or may develop secondary to injury, degenerative changes, or muscle spasm.

Normal Cervical Spine Alignment

• The normal sagittal alignment of the cervical spine is lordotic (curved forward), which helps distribute mechanical loads and maintain proper head positioning 1
• In the healthy population, cervical spine alignment varies considerably: approximately 36.5% have lordotic alignment, 36.5% have straight alignment, 17% have double curvature, and 10% have kyphotic alignment 2
• The internal architecture of cervical lordosis differs between genders - males typically have smaller upper cervical lordosis and higher lower cervical lordosis compared to females 1

What Constitutes Reversed Cervical Lordosis

• Reversed cervical lordosis occurs when the normal forward curve of the cervical spine is lost and becomes straight or develops a backward curve (kyphosis) 3
• This can be measured using various radiographic methods, including the Cobb method which measures the angle between the inferior endplates of C2 and C7 vertebrae 2, 1
• A negative angle using these measurements indicates kyphosis or reversed lordosis 4

Clinical Significance and Association with Symptoms

• The relationship between reversed cervical lordosis and clinical symptoms is complex and sometimes contradictory:

  • Some studies suggest that development of kyphosis and presence of local kyphosis may predict poor outcomes in patients with cervical spine conditions (p < 0.05) 4
  • However, other research indicates no significant difference in clinical outcomes between patients who develop kyphosis (-12.5°) and those who maintain lordosis (+1.1°) 4

• There is conflicting evidence regarding the association between cervical spine curvature and neck pain:

  • No significant difference has been found between patients with and without neck pain in relation to global curvature, segmental angles, or incidence of straight-spine or kyphotic deformity (p > 0.05) 5
  • Structural abnormalities in cervical alignment in patients with neck pain may be coincidental rather than causative 5

Potential Functional Implications

• Reversed cervical lordosis may affect certain physiological functions:

  • In elderly patients, excessive cervical lordosis has been shown to inhibit laryngeal elevation and influence swallowing function 6
  • When the lordotic curve is straightened in these cases, improvements in laryngeal elevation and pharyngeal transit time have been observed 6

• In cases of cervical radiculopathy, some evidence suggests that manipulative correction of reversed cervical lordosis may help alleviate symptoms 3

Post-Injury Considerations

• Alterations in normal cervical lordosis in patients with neck injury should be considered coincidental rather than directly caused by muscle spasm from the injury 2
• The incidence of different types of sagittal alignment (lordotic, straight, double curvature, kyphotic) shows no significant difference between patients with and without neck injury (p > 0.100) 2

Age and Developmental Factors

• While total cervical lordosis (FM-C7) does not significantly change between age groups, the internal architecture of cervical lordosis changes with age 1
• Children have more kyphotic vertebral body wedging (by approximately 7°) and more lordotic intervertebral disc wedging (by approximately 11°) compared to adults 1
• Gender differences in cervical lordosis are apparent even in childhood, with girls showing higher upper cervical lordosis than boys 1

Understanding the normal variations in cervical spine alignment and the potential clinical implications of reversed cervical lordosis is important for proper diagnosis and management of cervical spine conditions.