Diagnostic Considerations for Scapholunate Ligament Injury

Imaging Recommendations

The American College of Radiology recommends initial evaluation with conventional radiographs, with careful attention to positioning to assess for carpal malalignment, in individuals with suspected scapholunate ligament injury 1, 2
In low-grade injuries, radiographs are usually normal, but scapholunate diastasis >4 mm and dorsal tilt of the lunate >10° suggests dorsal intercalated segmental instability, according to the American College of Radiology 1
CT arthrography has the highest sensitivity (nearly 100%), specificity, and accuracy for detecting scapholunate ligament tears, as reported by the American College of Radiology 3
MRI (especially 3T) is commonly used with reported sensitivities of 65-89% for scapholunate ligament tears, according to the American College of Radiology 3
High-frequency ultrasound with dynamic "clenched fist" maneuvers can be useful with sensitivity of 46-100% and specificity of 92-100% for tears of the dorsal band, as reported by the American College of Radiology 3
For individuals with suspected or confirmed scapholunate ligament injury, imaging evaluation should start with conventional radiographs and progress to more advanced techniques like CT arthrography or MRI if needed, as recommended by the American College of Radiology 1, 3, 4

MR arthrography is more accurate than non-contrast MRI for determining which specific segments of the ligament are torn, as recommended by the American College of Radiology 5
CT arthrography and MR arthrography have similar accuracy for scapholunate ligament lesions, with CT arthrography being more sensitive for tears of the biomechanically important dorsal ligament fibers compared to conventional MRI 5
MRI and MR arthrography are more sensitive for diagnosis of extra-articular findings, such as ganglion cysts and tendon disorders, that can cause radial-sided pain 5

In patients with suspected scapholunate ligament tears, 3‑Tesla MRI shows a sensitivity of 65–89 % and specificity of 90–97 % for detecting these injuries. 6, 7

MR arthrography provides superior visualization compared with non‑contrast MRI and can identify the specific ligament segments that are torn, which is critical for surgical planning. 7

Dynamic high‑frequency ultrasound yields a sensitivity of 46–100 % and specificity of 92–100 % for detecting dorsal band tears of the scapholunate ligament. 6, 8

Both conventional MRI and MR arthrography have poor to moderate sensitivity for partial scapholunate ligament tears, limiting their reliability for these lesions. 6, 8
Dynamic instability of the scapholunate joint may be missed on standard MRI unless dedicated sequences are performed in pronation and supination positions. 6, 8
MRI and MR arthrography demonstrate limited accuracy for assessing extrinsic wrist ligaments, reducing their usefulness for comprehensive ligament evaluation. 6, 8