An Instrument-Assisted Coracoid Pain Test: An Exploratory Diagnostic Accuracy Study

Area of Science:

• Orthopedics
• Diagnostic Accuracy
• Musculoskeletal Disorders

Background:

• The coracoid pain test (CPT) is a clinical assessment for frozen shoulder (FS).
• Palpation-based CPT reliability may be limited by assessor variability.
• Improved diagnostic tools for frozen shoulder are needed.

Purpose of the Study:

• To evaluate the diagnostic accuracy of an instrument-assisted CPT.
• To compare the original CPT with pain severity and side comparison approaches for FS diagnosis.
• To assess the utility of these methods in identifying frozen shoulder.

Main Methods:

• An instrument-assisted CPT using a pressure algometer was performed on patients with FS and healthy controls.
• Sensitivity, specificity, and likelihood ratios were calculated for three approaches: original CPT, pain severity, and side comparison.
• 35 patients with FS and 35 healthy participants were included.

Main Results:

• The pain severity approach showed sufficient sensitivity, specificity, and likelihood ratios for FS diagnosis.
• The side comparison approach demonstrated excellent specificity and a positive likelihood ratio.
• The instrument-assisted CPT, in both original and alternative approaches, enhanced the probability of FS diagnosis.

Conclusions:

• Instrument-assisted CPT approaches, particularly pain severity, can aid in frozen shoulder diagnosis.
• The pain severity approach is valuable for ruling out FS with a negative result.
• Further cross-sectional studies are recommended to confirm these findings.