[Bursitis of the ulnar recess]

Evaluation of prestyloid recess morphology and ulnar-sided contrast leakage in CT arthrography of the wrist

Background

In wrist arthrograms, aberrant contrast material is frequently seen extending into the soft tissue adjacent to the ulnar styloid process. Since the prestyloid recess can mimic contrast leakage in CT arthrography, this study aims to provide a detailed analysis of its morphologic variability, while investigating whether actual ulnar-sided leakage is associated with injuries of the triangular fibrocartilage complex (TFCC).

Methods

Eighty-six patients with positive wrist trauma history underwent multi-compartment CT arthrography (40 women, median age 44.5 years). Studies were reviewed by two board-certified radiologists, who documented the morphology of the prestyloid recess regarding size, opening type, shape and position, as well as the presence or absence of ulnar-sided contrast leakage. Correlations between leakage and the presence of TFCC injuries were assessed using the mean square contingency coefficient (r_ɸ).

Results

The most common configuration of the prestyloid recess included a narrow opening (73.26%; width 2.26 ± 1.43 mm), saccular shape (66.28%), and palmar position compared to the styloid process (55.81%). Its mean length and anterior–posterior diameter were 6.89 ± 2.36 and 5.05 ± 1.97 mm, respectively. Ulnar-sided contrast leakage was reported in 29 patients (33.72%) with a mean extent of 12.30 ± 5.31 mm. Leakage occurred more often in patients with ulnar-sided TFCC injuries (r_ɸ = 0.480; p < 0.001), whereas no association was found for lesions of the central articular disc (r_ɸ = 0.172; p = 0.111).

Conclusions

Since ulnar-sided contrast leakage is more common in patients with peripheral TFCC injuries, distinction between an atypical configuration of the prestyloid recess and actual leakage is important in CT arthrography of the wrist.

Clinical tests and magnetic resonance imaging have limited diagnostic value for triangular fibrocartilaginous complex lesions

INTRODUCTION

The diagnostic value of clinical tests and magnetic resonance (MR) imaging for the investigation of triangular fibrocartilaginous complex (TFCC) lesions is not clear due to a lack of clinical data.

MATERIALS AND METHODS

We retrospectively analyzed 908 patients who underwent clinical tests and arthroscopy for suspected TFCC lesions at our institution. Further, MR imaging findings concerning the TFCC were gathered. We correlated clinical tests and MR imaging findings with those obtained during arthroscopy, and we calculated sensitivity, specificity, as well as positive and negative predictive values.

RESULTS

In the whole cohort, the positive predictive values of all clinical tests were low, ranging from 0.53 to 0.55. The ulna grinding test had the highest sensitivity, but lowest specificity. Sensitivity and specificity of the ulnar fovea sign and magnetic resonance imaging were similar, ranging from 0.73 to 0.76, and from 0.41 to 0.44, respectively. To some degree, the diagnostic value seemed to depend on the Palmer class of TFCC lesion.

CONCLUSIONS

According to this study, clinical tests and MR imaging findings are of very limited diagnostic value for the diagnosis of TFCC lesions.