High-Resolution Sonography of the Triangular Fibrocartilage:Initial Experience and Correlation with MRI and Arthroscopic Findings

Point-of-care wrist ultrasonography in trauma patients with ulnar-sided pain and instability

OBJECTIVE

We evaluated the effectiveness of point-of-care wrist ultrasonography compared with 3T-magnetic resonance imaging (MRI) for diagnosing triangular fibrocartilage complex (TFCC) injuries in trauma patients with ulnar-sided pain and instability. Moreover, we assessed the inter-observer variability between an emergency physician and a musculoskeletal radiology fellow.

MATERIAL AND METHODS

A prospective cross-sectional study was conducted in an emergency department; patients with ulnar-sided sprain and instability were recruited. An emergency physician and a musculoskeletal radiology fellow independently evaluated the TFC, meniscal homologue, volar and dorsal distal radioulnar ligaments, and extensor carpi ulnaris using point-of-care ultrasonography. Findings were classified as normal, partial rupture, or complete rupture. Wrist 3T-MRI was used as the reference standard. We compared the diagnostic values for point-of-care ultrasonography obtained by both reviewers using DeLong's test. Intra-class correlation coefficients (ICCs) were calculated for agreement between each reviewer and the reference standard, and directly between the two reviewers.

RESULTS

Sixty-five patients were enrolled. Point-of-care wrist ultrasonography showed acceptable sensitivity (97.2-99.1%), specificity (96.8-97.3%), and accuracy (96.9-97.9%); these diagnostic performance values did not differ significantly between reviewers (p=0.58-0.98). Agreement between each reviewer and the reference standard was excellent (emergency physician, ICC=0.964; musculoskeletal radiology fellow, ICC=0.976), as was the inter-observer agreement (ICC=0.968).

CONCLUSION

Point-of-care wrist ultrasonography is as precise as MRI for detecting TFCC injuries, and can be used for immediate diagnosis and further preoperative imaging. Moreover, it may shorten the interval from emergency department admission to surgical intervention while reducing costs.

Update TFCC: histology and pathology, classification, examination and diagnostics

The TFCC is a crucial stabilizer of the DRUJ. Based on its superficial and deep fibers, the TFCC guarantees unrestricted pronation and supination which is essential for performing sophisticated tasks. The ability to perform complex movements is of uppermost importance for hand function. Therefore, a functional intact TFCC is a prerequisite in this context. The articular disc of the TFCC is a fibrocartilaginous extension of the superficial zone of hyaline articular cartilage which arises from the radius. The peripheral 10-40 % of the TFC is vascularized. Degeneration of the articular disc is common with increasing age. Even though the central part of the articular disc is avascular, potential regeneration of lesions could be detected. The Palmer and Atzei classifications of TFCC lesions are complementary. TFCC innervation is based on different nerves. There is a high variability. A diligent clinical examination facilitates specific tests which help to allocate symptoms to the pathology. Therefore, a thorough clinical examination is not dispensable. Wrist arthroscopy remains the "gold standard" for diagnosing TFCC pathologies despite technical progress in imaging modalities. MR arthrography may have the potential to become a real alternative to wrist arthroscopy for diagnosing TFCC pathologies with technical progress in the future.

Anatomical study of the pisotriquetral joint ligaments using ultrasonography

OBJECTIVE

The aim of this study was to demonstrate that ultrasonography may allow a precise assessment of the primary stabilizers of pisotriquetral joint (pisohamate, pisometacarpal, and ulnar pisotriquetral ligaments).

METHODS AND MATERIALS

This study was initially undertaken in eight cadavers. Metal markers were placed in the ligaments using ultrasonographic guidance, followed by the dissection of the wrists. High-resolution ultrasonography was then performed in 15 volunteers (30 wrists) for the analysis of the presence, appearance, and thickness of the ligaments.

RESULTS

At dissection, the metal markers were located in the ligaments or immediately adjacent to them, confirming that they were correctly depicted using ultrasonography. The three ligaments could also be identified in each volunteer. The optimal positioning of the probe and the dynamic maneuvers of the wrist allowing the strain of these ligaments could be defined. No significant changes in the appearance and thickness of the ligaments could be observed.

CONCLUSIONS

The three ligaments stabilizing the pisotriquetral joint can be identified using ultrasonography. Further studies are now required to know whether this knowledge may be useful in the assessment of pain involving the ulnar part of the wrist.

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.

Ulnar-sided wrist pain. II. Clinical imaging and treatment

Pain at the ulnar aspect of the wrist is a diagnostic challenge for hand surgeons and radiologists due to the small and complex anatomical structures involved. In this article, imaging modalities including radiography, arthrography, ultrasound (US), computed tomography (CT), CT arthrography, magnetic resonance (MR) imaging, and MR arthrography are compared with regard to differential diagnosis. Clinical imaging findings are reviewed for a more comprehensive understanding of this disorder. Treatments for the common diseases that cause the ulnar-sided wrist pain including extensor carpi ulnaris (ECU) tendonitis, flexor carpi ulnaris (FCU) tendonitis, pisotriquetral arthritis, triangular fibrocartilage complex (TFCC) lesions, ulnar impaction, lunotriquetral (LT) instability, and distal radioulnar joint (DRUJ) instability are reviewed.

Normal ultrasound anatomy of the triangular fibrocartilage of the wrist: a study on cadavers and on healthy subjects

PURPOSE

To report the normal sonographic anatomy of the triangular fibrocartilage (TFC) of the wrist in cadavers and volunteers.

METHOD

Five hands from cadavers were examined sonographically before and after wrist dissection, during which the TFC was marked with surgical wires. Twenty volunteers without wrist limitation or pain, and without any history of wrist disease or inflammatory arthritis (mean age, 26 years (range,19-45 years) were also examined.

RESULTS

Sonograms showed that the meniscus and the TFC were clearly separated. The meniscus appeared as a triangular structure that was homogeneous and slightly hyperechoic. Compared with the meniscus, the TFC appeared hypoechoic. The same patterns were observed for cadavers and volunteers. In 3 volunteers (15%), the TFC was not visualized.

CONCLUSIONS

Using high-resolution ultrasound systems, the TFC can be separated from meniscus. However, visualization of the TFC remains limited due to its deep location and the presence of acoustic shadowing from bony structures.

Sonography and sonoarthrography of the scapholunate and lunotriquetral ligaments and triangular fibrocartilage disk: initial experience and correlation with arthrography and magnetic resonance arthrography

OBJECTIVE

The purpose of this study was to determine the utility of sonography and sonoarthrography in evaluation of dorsal bands of the scapholunate ligament (SLL), lunotriquetral ligament (LTL), and triangular fibrocartilage (TFC) disk in correlation with arthrography and magnetic resonance arthrography (MRA).

METHODS

High-resolution sonography of the SLL, LTL, and TFC disk was performed on symptomatic wrists in 16 patients referred by a hand surgeon for MRA of the symptomatic wrists. All patients then underwent arthrography and an MRA study of the same wrist. After MRA, sonography was repeated. The imaging findings of these different techniques were then compared. Four patients (25%) underwent surgery of their wrists. In these 4 patients, the surgical and imaging findings were correlated.

RESULTS

For the SLL, the results were concordant for all imaging modalities in 15 patients (93.75%) and partially concordant in 1 (6.25%). For the LTL, the results were concordant for all imaging modalities in 12 patients (75%), partially concordant in 3 (18.75%), and discordant in 1 (6.25%). For the TFC disk, the results were concordant for all imaging modalities in 13 patients (81.25%), partially concordant in 2 (12.5%), and discordant in 1 (6.25%). The arthroscopic and imaging findings were concordant for 3 SLLs, 3 LTLs, and 3 TFC disks.

CONCLUSIONS

Our preliminary results are encouraging. Sonography may be used at least as a screening imaging modality in evaluation of the SLL and TFC disk. Sonoarthrography improves evaluation of the LTL.

Modern imaging of the hand, wrist, and forearm

A review of the current state of the relevant diagnostic imaging technologies and methods and their clinical application in imaging common conditions of the hand, wrist, and forearm is presented. Evolving and future imaging technologies are also considered.

Normal Sonographic Anatomy of the Wrist and Hand

The advent of ultra-high-frequency sonographic transducers has significantly enhanced our ability to image superficial structures. As a result, sonography now can be used to assess injuries of the tendons in the wrist and hand. A clear understanding of normal sonographic anatomy is required to prevent misdiagnosis and ensure optimal patient care. The anatomy of the wrist and hand is best described by considering the extensor and flexor surfaces separately. The carpal extensor retinaculum divides the dorsal extensor tendons into six separate synovial compartments, which are demarcated by the points of its attachment to the radius and ulna. The course of these tendons from the wrist to the sites of their insertion can be traced by using sonography. The intrinsic wrist ligaments, triangular fibrocartilage, and dorsal finger extensor hood also can be assessed sonographically. The anatomy of the flexor surface of the wrist is defined principally by the flexor retinaculum. The median nerve, which is located deep to the retinaculum in the carpal tunnel, and the ulnar nerve, which is superficial to the retinaculum in the Guyon canal, can be easily detected. The long flexor tendons in the wrist and hand are also clearly depicted at sonography. The flexor annular pulley system is formed by five foci of thickening along the long flexor finger tendon synovial sheath, and the second and fourth annular pulleys can be identified sonographically in most patients. Sonography provides a rapid, cheap, noninvasive, and dynamic method for examination of the soft-tissue structures of the wrist and hand. Familiarity with the appearance of normal anatomic structures is a prerequisite for reliable interpretation of the resultant sonograms.

Ultrasonographic evaluation of normal extrinsic and intrinsic carpal ligaments: preliminary experience

OBJECTIVE

To determine normal anatomy of extrinsic and intrinsic carpal ligaments at ultrasonography (US).

DESIGN AND VOLUNTEERS

In the first part of the study, two musculoskeletal radiologists retrospectively reviewed in consensus the photographs of anatomic sections and dissections derived from 20 cadaveric wrists. This cadaveric study gave the two readers the opportunity to learn the anatomy and orientation of the various extrinsic and intrinsic carpal ligaments and, thus, to develop a US protocol to facilitate the recognition of each carpal ligament. In the second part of the study, these two radiologists prospectively and independently evaluated the visibility of extrinsic and intrinsic carpal ligaments in 30 wrists of volunteers, using the same US protocol.

RESULTS

With regard to extrinsic carpal ligaments, the radioscaphocapitate ligament (partially visible, 38%; completely visible, 62%), the radiolunotriquetral ligament (partially visible, 27%; completely visible, 73%), the palmar ulnotriquetral ligament (partially visible, 12%; completely visible, 88%), and the dorsal radiotriquetral ligament (partially visible, 7%; completely visible, 93%) were visualized at US. The dorsal ulnotriquetral ligament (partially visible, 21%; completely visible, 74%), the ulnolunate ligament (partially visible, 5%; completely visible, 70%), and the radial collateral ligament (partially visible, 18%; completely visible, 12%) were more difficult to recognize. The radioscapholunate ligament was never seen. With regard to intrinsic carpal ligaments, the dorsal (partially visible, 11%; completely visible, 89%) and palmar (partially visible, 38%; completely visible, 62%) scaphotriquetral ligaments as well as the dorsal scapholunate ligament (partially visible, 3%; completely visible, 97%) were visualized at US. The dorsal lunotriquetral ligament (partially visible, 39%; completely visible, 61%) and the palmar scapholunate ligaments (partially visible, 12%; completely visible, 81%) were more difficult to recognize.

CONCLUSION

US may be helpful in identifying the major extrinsic and intrinsic carpal ligaments.