Cloward Signs: Clinical Indicators in Cervical Spine Disorders

The Cloward signs are clinical indicators associated with cervical spine pathology, particularly cervical disc herniation or degeneration. These signs are named after Dr. Ralph Cloward, a pioneer in spinal surgery, and are used to help localize the affected cervical vertebrae based on the distribution of referred pain. Cloward signs referred pain patterns result from irritation or compression of cervical nerve roots due to disc herniation, spondylosis, or other degenerative changes.

Mechanism of Cloward Signs

The referred pain described by Cloward signs is due to the compression or irritation of the posterior longitudinal ligament and the annulus fibrosus, which are innervated by the sinuvertebral nerves. This nerve irritation causes pain to radiate along predictable dermatomal patterns that correspond to specific cervical spinal levels.

Typical Pain Patterns in Cloward Signs

1. C3-C4 Disc Pathology:

   • Pain referred to the base of the neck and the upper trapezius region.
   • May radiate to the scapular region.

2. C4-C5 Disc Pathology:

   • Pain referred to the midline of the scapula or the superior medial angle of the scapula.
   • Often associated with discomfort in the posterior shoulder region.

3. C5-C6 Disc Pathology:

   • Pain radiates to the interscapular region or mid-scapula area.
   • May involve the posterior shoulder blade.

4. C6-C7 Disc Pathology:

   • Pain referred to the inferior angle of the scapula.
   • Commonly extends to the posterior arm and forearm along the corresponding dermatome.

Clinical Utility of Cloward Signs

Cloward signs help clinicians:

• Localize the Affected Cervical Level:
  By identifying the referred pain pattern, healthcare providers can pinpoint the specific spinal level involved.

• Guide Diagnostic Imaging:
  Observing Cloward signs can help target imaging studies like MRI or CT scans to the suspected cervical levels.

• Differentiate Cervical Pathology from Other Conditions:
  Helps distinguish cervical spine disorders from conditions like shoulder impingement or thoracic outlet syndrome.

Limitations

While Cloward signs provide valuable clues, they are not definitive for diagnosis. Pain patterns can overlap due to:

• Variations in nerve root innervation.
• Coexisting musculoskeletal or neurological conditions.
• Referred pain from other sources, such as shoulder or thoracic pathology.

Diagnostic imaging and other clinical tests, such as Spurling's maneuver or nerve conduction studies, are often required to confirm the diagnosis.

Conclusion

Cloward signs remain a useful clinical tool in assessing cervical spine disorders. By correlating referred pain patterns with specific cervical levels, clinicians can better localize the site of pathology and guide further evaluation and treatment. However, these signs should always be interpreted alongside imaging studies and a comprehensive clinical examination for accurate diagnosis and management.