Wrist arthrography: a simple method

Sonographically guided distal radioulnar joint injection: technique and validation in a cadaveric model

Distal radioulnar joint (DRUJ) disorders are uncommon but important causes of ulnar-sided wrist pain and disability. Fluoroscopically guided injections may be performed to diagnose or treat DRUJ-related pain or as part of a diagnostic arthrogram. Sonographic guidance may provide a favorable alternative to fluoroscopic guidance for distal DRUJ injections. This report describes and validates a sonographically guided technique for DRUJ injections in an unembalmed cadaveric model. An experienced clinician used sonographic guidance to inject diluted colored latex into the DRUJs of 10 unembalmed cadaveric specimens. Subsequent dissection by a fellowship-trained hand surgeon confirmed accurate injections in all 10 specimens. Two cases of ulnocarpal flow, indicative of triangular fibrocartilage injury, were noted during injection and subsequently confirmed during dissection. Clinicians should consider using sonographic guidance to perform DRUJ injections when clinically indicated. Further research should explore the efficacy of sonographically guided DRUJ injections to treat patients with painful DRUJ syndromes or to evaluate the triangular fibrocartilage complex in patients with ulnar wrist pain syndromes.

Differences between radial and ulnar deviation of the wrist in the study of the intrinsic intercarpal ligaments: magnetic resonance imaging and gross anatomic inspection in cadavers

OBJECTIVE

To demonstrate how radial and ulnar deviation of the wrist can affect the visualization of the intrinsic intercarpal ligaments using magnetic resonance (MR) imaging, MR arthrography and gross anatomic inspection in cadavers.

MATERIALS AND METHODS

The detectability of the intrinsic intercarpal ligaments of ten fresh human wrists was analyzed in coronal, axial and sagittal images in the neutral position and in radial and ulnar deviation with MR imaging and MR arthrography. The findings were then correlated with gross anatomic inspection. Additionally, quantitative measurements including the radiocarpal distances and capitate angles were performed.

RESULTS

Differences were noted in the visual conspicuity of only the intercarpal ligaments of the proximal carpal row with different techniques and wrist positions. The average width of the radiocarpal joint was 0.62 mm, 1.55 mm and 2.0 mm (radial side) and 3.78 mm, 2.25 mm and 1.16 mm (ulnar side) in radial deviation, neutral position, and ulnar deviation of the wrist, respectively. Statistically, these maneuvers produced significant opening in the ulnar side during radial deviation (Student's t-test; P = 0.0005) and in the radial side in ulnar deviation (P = 0.007).

CONCLUSION

Significant differences in the width of the radiocarpal joint were observed during radial and ulnar deviation of the wrist, influencing the visualization of the intrinsic ligaments, mainly the scapholunate and lunotriquetral ligaments. The use of MR arthrography with radial and/or ulnar deviation has the potential to improve diagnosis in clinical cases in which injury to one or both of these ligaments is suggested.

Role of MR imaging in chronic wrist pain

Magnetic resonance (MR) imaging for chronic wrist pain is challenging. Correct assessment of the triangular fibrocartilage, hyaline cartilage, ligaments, and tendons has become mandatory for comprehensive decision making in wrist surgery. The MR technique, potential and limits of MR imaging in patients with chronic wrist pain will be discussed. MR arthrography with injection of gadolinium-containing contrast material into the distal radioulnar joint is suggested for evaluation of the triangular fibrocartilage. The clinically meaningful ulnar-sided peripheral tears are otherwise hard to diagnose. The diagnostic performance of MR imaging for interosseous ligament tears varies considerably. The sensitivity for scapholunate ligament tears is consistently better than for lunotriquetral ligament tears. Gadolinium-enhanced MR imaging is considered to be the best technique for detecting established avascularity of bone, but the assessment of the MR results remains challenging. Most cases of ulnar impaction syndrome have characteristic focal signal intensity changes in the ulnar aspect of the lunate. Avascular necrosis of the lunate (Kienböck's disease) is characterized by signal changes starting in the proximal radial aspect of the lunate. MR imaging is extremely sensitive for occult fractures. Questions arise if occult posttraumatic bone lesions seen on MR images only necessarily require the same treatment as fractures evident on plain films or computed tomography (CT) images. MR imaging and ultrasound are equally effective for detecting occult carpal ganglia. Carpe bossu (carpal boss) is a bony protuberance of a carpometacarpal joint II and III which may be associated with pain.

Carpal instability

This review addresses the pathoanatomical basics as well as the clinical and radiological presentation of instability patterns of the wrist. Carpal instability mostly follows an injury; however, other diseases, like CPPD arthropathy, can be associated. Instability occurs either if the carpus is unable to sustain physiologic loads ("dyskinetics") or suffers from abnormal motion of its bones during movement ("dyskinematics"). In the classification of carpal instability, dissociative subcategories (located within proximal carpal row) are differentiated from non-dissociative subcategories (present between the carpal rows) and combined patterns. It is essential to note that the unstable wrist initially does not cause relevant signs in standard radiograms, therefore being "occult" for the radiologic assessment. This paper emphasizes the high utility of kinematographic studies, contrast-enhanced magnetic resonance imaging (MRI) and MR arthrography for detecting these predynamic and dynamic instability stages. Later in the natural history of carpal instability, static malalignment of the wrist and osteoarthritis will develop, both being associated with significant morbidity and disability. To prevent individual and socio-economic implications, the hand surgeon or orthopedist, as well as the radiologist, is challenged for early and precise diagnosis.