Bilateral Ulnar Deviation Supination Stress Test to Assess Dynamic Scapholunate Instability

Area of Science:

• Orthopedic Surgery
• Radiology
• Sports Medicine

Background:

• Scapholunate ligament injuries are common causes of wrist pain and dysfunction.
• Dynamic scapholunate dysfunction can be challenging to diagnose with standard imaging techniques.

Purpose of the Study:

• To introduce and evaluate a novel radiologic test, the Bilateral Ulnar Deviation Supination (BUDS) test.
• To assess the integrity of the scapholunate ligament in cases of dynamic scapholunate dysfunction.

Main Methods:

• A bilateral forearm-holding device was used for comparative radiographic assessment.
• The test involved resisted isometric contraction of the extensor carpi ulnaris muscle with forearm supination.
• 12 patients' wrists were analyzed retrospectively, comparing symptomatic and asymptomatic wrists using the BUDS test, with arthroscopy as the reference standard.

Main Results:

• The BUDS test was positive in 7 patients, showing a mean scapholunate joint gap of 4.8 mm.
• BUDS-positive patients had a mean joint gap difference of 2.6 mm between wrists, correlating with Geissler stage III or IV ruptures.
• BUDS-negative patients had a mean difference of 0.2 mm, with no or minimal ligament injury (Geissler stage I).

Conclusions:

• The BUDS test is a novel radiologic method for accurately assessing dynamic scapholunate dysfunction.
• The study found a correlation between radiographic findings from the BUDS test and arthroscopic surgical findings.
• Further research is recommended to confirm the test's validity and reliability in clinical practice.