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Hand Case 10 Diagnosis

UCL Thumb Injury


If you suspect a UCL injury, standard thumb X rays should be performed. If no avulsion fracture is present, valgus stress should be applied to test for UCL laxity. The MCP joint is flexed to 30 degrees and pressure is applied to the radial aspect of the MCP. Perform stress testing on the un-injured thumb too, to determine if any laxity is from injury or is normal for that patient. Sometimes patients cannot undergo stress testing without local anesthesia.