Dynamic Evaluation of Dorsal Scapholunate Ligament

The scapholunate ligament (SL) is one of the most clinically signicant ligaments of the wrist and unfortunately, its injuries often are not diagnosed or treated during the acute phase of injury, when direct repair of the ligament would be possible. It has three components – volar, dorsal, and interosseous. The dorsal and volar represent true ligaments, whereas the interosseous component is fibrocartilage.  All of the surgeons needs to know as much information as possible about the ligament anatomy and its relationships with other carpal structures, especially under dynamic conditions. In an interesting paper, Wrist MRI and Carpal Instability: What the Surgeon Needs to Know, and the Case for Dynamic Imaging the author closes the abstract with these words: “Providing specifics about the clinical questions that arise with various carpal instabilities serves to highlight the challenges facing current imaging technology, and provides a framework that supports the argument for the development of dynamic MRI as one-and perhaps the only-truly satisfactory solution to this problem“. I agree with him, definitely. In my daily practice I always perform both dynamic Mri and ultrasound examination; I find very attractive the study of carpal stability with dynamic Mri and ultrasound imaging. First knowing the normal appearance of carpal behaviour, then carpal instability.

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Normal appearance of dorsal scapholunate ligament: Coronal Ge stir, 3D and X-bone T1w Mri scans (0.3 Tesla).


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Axial and Sagittal T2w Mri scans (0.3 Tesla). Perfect allignement of the central osseus carpal chain is evident on sagittal scan.

Dynamic Mri of dorsal scapholunate ligament: radial and ulnar deviation.

See the video below and enjoy your practice!

 

 

 

 

Bifid Median Nerve

During a standard wrist ultrasound exam, it might happen to find a bifid median nerve. According to literature it has an incidence of ~3% and may be accompanied by an accessory artery, the persistent median artery of the forearm, which lies in between the two nerve bundles.

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Axial ultrasound and T2w Mri scan (0.3 Tesla)

Especially in case of carpal tunnel release it is essential that this particular anatomy be mentioned in your report in order to avoid iatrogenic injuries. Mri scan togheter with dynamic ultrasound examination and electromyography are the best choice for the evaluation of peripheral neuropathies.