Asian Spine J.  2018 Feb;12(1):69-73. 10.4184/asj.2018.12.1.69.

Biceps-Related Physical Findings Are Useful to Prevent Misdiagnosis of Cervical Spondylotic Amyotrophy as a Rotator Cuff Tear

• Iwata E
• Shigematsu H
• Inoue K
• Egawa T
• Tanaka M
• Okuda A
• Morimoto Y
• Masuda K
• Yamamoto Y
• Sakamoto Y
• Koizumi M
• Tanaka Y

• KMID: 2403598
• DOI: http://doi.org/10.4184/asj.2018.12.1.69

Abstract

STUDY DESIGN: Case-control study. PURPOSE: The aim of the present study was to identify physical findings useful for differentiating between cervical spondylotic amyotrophy (CSA) and rotator cuff tears to prevent the misdiagnosis of CSA as a rotator cuff tear. OVERVIEW OF LITERATURE: CSA and rotator cuff tears are often confused among patients presenting with difficulty in shoulder elevation.
METHODS
Twenty-five patients with CSA and 27 with rotator cuff tears were enrolled. We included five physical findings specific to CSA that were observed in both CSA and rotator cuff tear patients. The findings were as follows: (1) weakness of the deltoid muscle, (2) weakness of the biceps muscle, (3) atrophy of the deltoid muscle, (4) atrophy of the biceps muscle, and (5) swallow-tail sign (assessment of the posterior fibers of the deltoid).
RESULTS
Among 25 CSA patients, 10 (40.0%) were misdiagnosed with a rotator cuff tear on initial diagnosis. The sensitivity and specificity of each physical finding were as follows: (1) deltoid weakness (sensitivity, 92.0%; specificity, 55.6%), (2) biceps weakness (sensitivity, 80.0%; specificity, 100%), (3) deltoid atrophy (sensitivity, 96.0%; specificity, 77.8%), (4) biceps atrophy (sensitivity, 88.8%; specificity, 92.6%), and (5) swallow-tail sign (sensitivity, 56.0%; specificity, 74.1%). There were statistically significant differences in each physical finding.
CONCLUSIONS
CSA is likely to be misdiagnosed as a rotator cuff tear; however, weakness and atrophy of the biceps are useful findings for differentiating between CSA and rotator cuff tears to prevent misdiagnosis.

Keyword

Biceps muscle; Deltoid muscle; Rotator cuff; Cervical spondylosis; Differential diagnosis

MeSH Terms

Atrophy
Deltoid Muscle
Diagnosis
Diagnosis, Differential
Diagnostic Errors*
Humans
Rotator Cuff*
Sensitivity and Specificity
Shoulder
Spondylosis
Tears*