Extension Stress Test | CMC 1 Osteoarthritis

Go to

Extension Stress Test | CMC 1 Osteoarthritis | Thumb OA

Thumb osteoarthritis (OA) is a painful and debilitating condition that affects a large proportion of the adult population, with radiographic prevalence reaching 90% in both men and women by the age of 80. This condition can cause pain at the base of the thumb, progressive loss of thumb motion, weakness, and decreased coordination, which worsens over time.

Qualitative assessment of the history, physical examination, and radiographs are used to diagnose and treat thumb CMC arthritis. The location, duration, onset, frequency, intensity, and quality of the pain are all under consideration.

Gelberman et al. (2015) evaluated this test and found a sensitivity of 94% and specificity of 95% and inter-rater reliability Kappa coefficient of 0.84. Despite these excellent values the study represents with several limitations for this novel assessment test and until further validation of this test in different settings has taken place, we give it a moderate clinical value.

To conduct the test, the patient is in sitting position across from the examiner. The patient’s hand is placed on the examination table with the elbow flexed to 90 degrees and the forearm in neutral rotation. While the examiner supports the patient’s ulnar side of the hand to maintain the wrist in neutral position and to prevent ulnar deviation, the other hand is placed such that the examiner’s ipsilateral thumb is along the radial aspect of the distal

thumb metacarpal, 5 to 10 mm proximal to the thumb metacarpophalangeal joint. Then the examiner firmly extends the patient’s thumb until the thumb metacarpal comes to lie in a plane parallel to the palm or until a firm end-feel is reached.

The test is considered positive if the patient’s pain at the TMC joint is reproduced.