Posterior Compression Test: a Provocative Test for Detecting Posterior Labral Tears.

Area of Science:

• Orthopedic Surgery
• Diagnostic Accuracy Studies
• Shoulder Arthroscopy

Background:

• Posterior labral tears are a common cause of shoulder pain and dysfunction.
• Accurate diagnosis is crucial for effective treatment planning.
• Existing diagnostic tests may have limitations in identifying posterior labral pathology.

Purpose of the Study:

• To evaluate the diagnostic accuracy of the posterior compression test (PCT) for suspected posterior labral tears.
• To compare the PCT's performance against arthroscopic findings.

Main Methods:

• Retrospective review of 191 patients undergoing arthroscopic labral repair with pre-operative PCT or Jerk test data.
• Patients were categorized into 'non-posterior' (anterior, SLAP) and 'any posterior' (isolated posterior, SLAP with posterior extension, pan-labral) tear groups.
• Diagnostic metrics including sensitivity, specificity, PPV, NPV, and AUC/ROC were calculated.

Main Results:

• The PCT demonstrated high sensitivity (92.6%) and specificity (86.5%) for isolated posterior labral tears.
• Combining the PCT with the Jerk test increased sensitivity to 96.3% with an AUC of 0.855.
• The PCT exhibited a low false-positive rate (13.5%) in the non-posterior labral tear group.

Conclusions:

• The posterior compression test is a valuable diagnostic tool for posterior labral pathology.
• The PCT shows good correlation with arthroscopic diagnoses, potentially through direct stimulation.
• Combination with the Jerk test enhances diagnostic yield for posterior labral tears.