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

Diagnostic performance of high-resolution ultrasound in the evaluation of intrinsic and extrinsic wrist ligaments after trauma

PURPOSE

To investigate the role of ultrasound (US) in the evaluation of intrinsic and extrinsic ligaments of the wrist with magnetic resonance arthrography (MRA) as the reference standard.

MATERIALS AND METHODS

This prospective study included patients referred for MRA after wrist trauma. US examination was performed just before MRA. On the dorsal and palmar sides of the wrist, the intrinsic interosseus and midcarpal, extrinsic, and collateral ligaments were evaluated. MRA was performed on a 1.5-T unit. In the first 20 patients included, ligament thickness was independently assessed using US and MRA and thickness reproducibility was calculated. Ligament integrity was evaluated in all patients.

RESULTS

38 patients (22 men, 16 women; mean age: 38 years) were included. Ligament thickness reproducibility ranged between 44% for the palmar ulnocapitate ligament and 71% for the palmar scaphotriquetral ligament. US had a sensitivity, specificity, positive and negative predictive values, and accuracy of 100% in the identification of tears of the palmar (n=8) and dorsal (n=3) bands of the scapholunate ligament and the ulnar collateral ligament (n=3). It had a sensitivity of 100%, specificity of 97%, positive predictive value of 50%, negative predictive value of 100%, and accuracy of 97% in the identification of tears of the palmar ulnolunate ligament (n=1).

CONCLUSION

Compared to MRA, US showed good reproducibility in the assessment of wrist ligament thickness and similar accuracy with respect to identifying tears of the scapholunate, palmar ulnolunate, and ulnar collateral ligaments.

[Establishing a standardized diagnostic Procedure for sonographic Imaging and Evaluation of the scapholunate Ligament]

BACKGROUND

Ultrasound has not yet been established in the diagnostic workup of scapholunate ligament lesions. We aimed to develop a standardised examination procedure to visualise and evaluate the SL ligament.

PATIENTS AND METHODS

Forty patients (70 hands) were examined prospectively with ultrasonography and the results were compared with arthroscopy and MRI findings. We studied the visibility of the SL ligament and the SL distance on side-to-side comparison and performed a method comparison between MRI/arthroscopy and ultrasound, testing for distinction and accordance. Cut-off values for the SL distance indicating a lesion were determined and all parameters were used for developing a score.

RESULTS

An intact ligament appears as a hyperechogenic, fibrillary structure and shows discontinuity or a hypoechogenic space when injured. An intact ligament was visible dorsally in 89.6 % and palmarly in 83.3 %. The SL distance for an intact ligament was 5/2/5.1 mm for the dorsal/middle/palmar aspect (range 3.2-6.7/0.9-4/3.1-7.8 mm) and 6.4/3/6.3 mm (range 5-9.4/2-6.2/4-9.3 mm) for a lesion. The difference between the right and left hand with an intact ligament was a maximum of 2.1/1.1/1.8 mm, an average of 0.4/0.2/0.2 mm; in case of an injury, the maximum difference was 1.2/0.9/1.1 mm. Distance values for radial and ulnar deviation were physiological but partly unpredictable. The cut-off values determined for a lesion are 5.05 mm for the dorsal aspect (sensitivity/specificity 0.95/0.60), 1.95 mm for the middle (1/0.62) and 6.15 mm for the palmar aspect (0.55/0.85). The created sonographic SL ligament score has a high AUC (area under the curve) of 0.93, a sensitivity of 85 % and a specificity of 90 %.

CONCLUSION

The parameters, especially when combined to a score, allow to state whether the SL ligament is intact or not. Ultrasound can, therefore, be recommended as a diagnostic and screening method for an SL ligament lesion und should be used as a routine tool. The criteria must be checked from a perspective with high case numbers.

Usefulness of the Ultrasound in Hand Surgery: Part I

In the last years, ultrasonography (US) of the wrist and hand have increased in popularity. Technical advances led us to improve image quality and have the ability to see superficial soft-tissue structures with high resolution with the patient in our office.

The advantages of US are the fact that it is noninvasive, its lack of ionising radiation, low cost, and portability. The dynamic real-time assessment in the office is an additional benefit.

Ultrasound can be used in hand surgery for both diagnostic and therapeutic purposes. We can use US for injections with needle guidance, for the evaluation of soft-tissue masses, foreign bodies, tendon injuries, compressive neuropathies, and rheumatologic joint disease. It also helps us perform ultrasound-guided procedures: carpal tunnel syndrome, trigger finger, and intersection syndrome or compartimental syndrome.

The aim of the present review is to describe different uses of US in hand surgery to show its important role of providing to the surgeon more information on the diseases of their patients.

Feasibility of ultrasound-based measurement of dorsal scaphoid displacement: A 3D-model study

The present study aimed to develop a reliable dynamic measurement technique, which can be used directly in the outpatient setting, based on dorsal subluxation of the scaphoid on scaphoid shift test. This study was designed to evaluate feasibility and to quantify dorsal subluxation of the scaphoid in relation to the lunate. Based on a scaphoid shift test under ultrasonography, a standardized 3D test model was developed to measure subluxation. Sagittal subluxation ranged between 0 and 6 mm, as checked on the implemented scale. Four hand surgeons trained in ultrasonography (experience level II-V) performed blinded measurements (total of 52, n = 13 per investigator) with a standardized measurement protocol. Dorsal subluxation of the scaphoid was measured in relation to the lunate. Interobserver reliability on intraclass correlation coefficient (ICC) was excellent, at 0.97 (95% confidence interval, 0.930-0.992). Mean overall absolute measurement error was 0.27 mm ± 0.21. Dorsal subluxation of the scaphoid can thus be accurately measured on ultrasound with excellent interobserver reliability, quantifying and improving clinical assessment of scapholunate instability.

Ultrasonographic Classification of Scapholunate Interosseous Ligament Injury Associated With Distal Radius Fracture

PURPOSE

Although scapholunate interosseous ligament (SLIL) injury is often associated with distal radius fracture, it is frequently missed in x-rays. The purpose of this study was to develop a diagnostic classification based on ultrasonography for SLIL injury and evaluate its diagnostic accuracy.

METHODS

Patients who required surgery for distal radius fracture were included in this study. Ultrasonography and arthroscopy were performed in all patients. The original ultrasonography-based classification of the dorsal part of SLIL was developed as follows: for type A, the SLIL surface was outlined clearly as a continuous flat line; for type B, the SLIL surface was outlined clearly as a continuous bulged line; and for type C, the SLIL surface was not continuous, smooth, or outlined clearly. Arthroscopy was performed at the time of osteosynthesis. We classified its findings according to the arthroscopic classification system of Geissler et al and evaluated interobserver and intraobserver reliabilities for our classification on ultrasonography. We also studied the relationship between the ultrasonographic and arthroscopic classifications.

RESULTS

In total, 40 patients were included in this study. Weighted κ values for interobserver and intraobserver reliabilities for our ultrasonographic classification were 0.83 (95% confidence interval, 0.70-0.96) and 0.88 (95% confidence interval, 0.77-0.99), respectively. There were 17 patients with type A, 14 with type B, and 9 with type C on ultrasonography. Ultrasonography had a sensitivity of 64% and specificity of 93% for the assumption that type C on ultrasonography corresponded to Geissler grades 3 and 4 on arthroscopy. No patient with type A on ultrasonography was classified as Geissler grades 3 and 4 on arthroscopy.

CONCLUSIONS

We concluded that ultrasonography has a high specificity but low sensitivity for the diagnosis of SLIL injury.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic Ⅱ.

Ultrasonography for Dorsal-Sided Wrist Pain in a Combat Environment: Technique, Pearls, and a Case Report of Dynamic Evaluation of the Scapholunate Ligament

Ultrasonography is a commonly utilized tool in orthopedic surgery for the diagnosis and treatment of a variety of musculoskeletal conditions, including pathology about the wrist. Its value should not be underestimated when other diagnostic resources are unavailable - such as in a combat setting where ultrasounds, but not X-ray, are a standard equipment item. An active duty soldier presented to an orthopedic provider in an austere environment with chronic dorsal wrist pain due to a previous fall. Physical examination and dynamic ultrasound examination allowed the deployed provider to diagnose a scapholunate ligament injury. The patient was appropriately evacuated to a higher level of care without the need for X-ray or other advanced imaging modalities. Making this readily available resource a standard tool for providers deployed to a forward location could be beneficial for efficient and appropriate patient evacuation for musculoskeletal injuries. It can also rule out injuries that would otherwise have required unnecessary soldier movement through hostile territory for diagnostic tests such as X-rays. In addition, a simple technique and pearls for ultrasonography of the wrist are provided.

Ulnar Wrist Pain Revisited: Ultrasound Diagnosis and Guided Injection for Triangular Fibrocartilage Complex Injuries

The triangular fibrocartilage complex (TFCC) serves as the major stabilizer of the wrist. Its injuries can result from trauma or degeneration, both of which are strongly correlated with the loading stress on the ulnar shaft and carpal joints. The TFCC is made of the articular disc, meniscus homologue, ulnocarpal ligament, radioulnar ligament, ulnotriquetral ligament, ulnolunate ligament, and subsheath of the extensor carpi ulnaris tendon. Because of its complexity, it is challenging to confirm the exact component affected in TFCC injuries. The Palmer classification is widely used for investigation of TFCC lesions using magnetic resonance imaging. Recently, high-resolution ultrasound (US) has become more popular in diagnosing musculoskeletal disorders. However, the utility of US imaging in TFCC lesions is less common because its anatomy under US imaging is not described in the current literature. Accordingly, in this review, we aimed to propose a standard US scanning protocol for the TFCC, present relevant images for its pathologies, and illustrate appropriate US-guided injection techniques for their management.

The Quantitative Anatomy of the Dorsal Scapholunate Interosseous Ligament

BACKGROUND

The anatomy of the scapholunate interosseous ligament (SLIL) has been described qualitatively in great detail, with recognition of the dorsal component's importance for carpal stability. The purpose of this study was to define the quantitative anatomy of the dorsal SLIL and to assess the use of high-frequency ultrasound to image the dorsal SLIL.

METHODS

We used high-frequency ultrasound imaging to evaluate 40 wrists in 20 volunteers and recorded the radial-ulnar (length) and dorsal-volar (thickness) dimensions of the dorsal SLIL and the dimensions of the scapholunate interval. We assessed the use of high-frequency ultrasound by comparing the length and thickness of the dorsal SLIL on ultrasound evaluation and open dissection of 12 cadaveric wrists. Student's t test was used to assess the relationship between measurements obtained on cadaver ultrasound and open dissection.

RESULTS

In the volunteer wrists, the mean dorsal SLIL length was 7.5 ± 1.4 mm and thickness was 1.8 ± 0.4 mm; the mean scapholunate interval was 5.0 mm dorsally and 2.5 mm centrally. In the cadaver wrists, there was no difference in dorsal SLIL length or thickness between ultrasound and open dissection.

CONCLUSIONS

The dorsal SLIL is approximately 7.5 mm long and 1.8 mm thick. These parameters may be useful in treatment of SLIL injuries to restore the native anatomy. High-frequency ultrasound is a useful imaging technique to assess the dorsal SLIL, although further study is needed to assess the use of high-frequency ultrasound in detection of SLIL pathology.

Imaging of Wrist Injuries: A Standardized US Examination in Daily Practice

The keys to successful ultrasonography (US) of the wrist include knowledge of the relevant anatomy and understanding the biomechanical aspects. A wide spectrum of pathological findings including bone fractures (scaphoid, triquetrum) and ligament lesions (dorsal intercarpal and radiocarpal ligaments, scapholunate ligament) can be caused by an identical traumatic mechanism determined on the basis of the position of wrist at the time of injury.

In the setting of wrist trauma, an early diagnosis can minimize the potential for inappropriate or delayed treatment. We describe a practical radiological approach by using a standardized imaging protocol: standard radiographs (four views) associated with an US examination focused on seven landmarks. If there is discordance between clinical and radiological features or if the diagnosis of a disruption of the scapholunate ligament remains uncertain, additional cross-sectional imaging (MRI or CT arthrogaphy) should be performed.

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.

Dynamic high-resolution ultrasound of intrinsic and extrinsic ligaments of the wrist: How to make it simple

Wrist ligaments are crucial structures for the maintenance of carpal stability. They are classified into extrinsic ligaments, connecting the carpus with the forearm bones or distal radioulnar ligaments, and intrinsic ligaments, entirely situated within the carpus. Lesions of intrinsic and extrinsic ligaments of the wrist have been demonstrated to occur largely, mostly in patients with history of trauma and carpal instability, or rheumatoid arthritis. Ultrasound allows for rapid, cost-effective, non-invasive and dynamic evaluation of the wrist, and may represent a valuable diagnostic tool. Although promising results have been published, ultrasound of wrist ligaments is not performed in routine clinical practice, maybe due to its technical feasibility regarded as quite complex. This review article aims to enlighten readers about the normal sonographic appearance of intrinsic and extrinsic carpal ligaments, and describe a systematic approach for their sonographic assessment with detailed anatomic landmarks, dynamic manoeuvres and scanning technique.

Imaging in carpal instability

Carpal instability is a complex and heterogeneous clinical condition. Management requires accurate identification of structural injury with an understanding of the resultant movement (kinematic) and load transfer (kinetic) failure. Static imaging techniques, such as plain film radiography, stress views, ultrasound, magnetic resonance, MR arthrography and computerized tomography arthrography, may accurately depict major wrist ligamentous injury. Dynamic ultrasound and videofluoroscopy may demonstrate dynamic instability and kinematic dysfunction. There is a growing evidence base for the diagnostic accuracy of these techniques in detecting intrinsic ligament tears, but there are limitations. Evidence of their efficacy and relevance in detection of non-dissociative carpal instability and extrinsic ligament tears is weak. Further research into the accuracy of existing imaging modalities is still required. Novel techniques, including four-dimensional computerized tomography and magnetic resonance, can evaluate both cross-sectional and functional carpal anatomy. This is a narrative review of level-III studies evaluating the role of imaging in carpal instability.

The accuracy of diagnostic ultrasound imaging for musculoskeletal soft tissue pathology of the extremities: a comprehensive review of the literature

Musculoskeletal diagnostic ultrasound imaging (MSK-DUSI) has been growing outside the traditional radiology speciality. Increased use of this technology has been reported in several healthcare settings, however an apparent gap in the knowledge of the accuracy of this diagnostic technology indicated a review was warranted. We undertook a structured review of the literature to assess the accuracy of MSK-DUSI for the diagnosis of musculoskeletal soft tissue pathology of the extremities. An electronic search of the National Library of Medicine’s PubMed database (1972 to mid-2014) was conducted. All relevant systematic reviews of diagnostic studies, all diagnostic studies published after the date of the latest systematic reviews and relevant diagnostic studies outside the scope the systematic reviews that directly compared the accuracy of MSK-DUSI (the index test) to an appropriate reference standard for the target condition were included. A fundamental appraisal of the methodological quality of studies was completed. The individual sensitivity, specificity and likelihood ratio data were extracted and entered into diagnostic accuracy tables. A total of 207 individual studies were included. The results show that MSK-DUSI has acceptable diagnostic accuracy for a wide spectrum of musculoskeletal conditions of the extremities. However, there is a lack of high quality prospective experimental studies in this area and as such clinicians should interpret the results with some caution due to the potential for overestimation of diagnostic accuracy.

Cine MRI: a new approach to the diagnosis of scapholunate dissociation

OBJECTIVE

To evaluate the feasibility of cine MRI for the detection of scapholunate dissociation (SLD) and to compare the sensitivity and specificity of cine MRI with those of cineradiography and arthroscopy.

MATERIALS AND METHODS

To evaluate feasibility, healthy subjects underwent cine MRI of the wrist. To evaluate sensitivity and specificity, patients with clinically suspected scapholunate ligament (SLL) injury after trauma to the wrist were prospectively included and underwent radiographic examination, cineradiography, and cine MRI. In 25 out of 38 patients, subsequent arthroscopy was performed. Results of cineradiography and cine MRI correlated with those of arthroscopy.

RESULTS

Cine MRI was of diagnostic quality in all healthy subjects and patients with good interrater agreement. There was excellent correlation between cineradiography and cine MRI. Scapholunate distance differed significantly between healthy subjects and patients with scapholunate dissociation (p < 0.001), but not between imaging modalities in the patient group. Cine MRI had 85% sensitivity and 90% specificity for the detection of SLD.

CONCLUSION

Cine MRI of the wrist is a fast and reliable technique for the detection of SLD with diagnostic accuracy comparable to cineradiography. It can be easily implemented as a routine clinical MRI examination, facilitating diagnostic workup of patients with suspected SLD while avoiding radiation exposure.

Wrist ultrasound examination - scanning technique and ultrasound anatomy. Part 1: Dorsal wrist

Ultrasound imaging of the musculoskeletal system is superior to other imaging methods in many aspects, such as multidimensional character of imaging, possibility of dynamic evaluation and precise assessment of soft tissues. Moreover, it is a safe and relatively inexpensive method, broadly available and well-tolerated by patients. A correctly conducted ultrasound examination of the wrist delivers detailed information concerning the condition of tendons, muscles, ligaments, nerves and vessels. However, the knowledge of anatomy is crucial to establish a correct ultrasound diagnosis, also in wrist assessment. An ultrasound examination of the wrist is one of the most common US examinations conducted in patients with rheumatological diseases. Ultrasonographic signs depend on the advancement of the disease. The examination is equally frequently conducted in patients with pain or swelling of the wrist due to non-rheumatological causes. The aim of this publication was to present ultrasound images and anatomic schemes corresponding to them. The correct scanning technique of the dorsal part of the wrist was discussed and some practical tips, thanks to which highly diagnostic images can be obtained, were presented. The following anatomical structures should be visualized in an ultrasound examination of the dorsal wrist: distal radio-ulnar joint, radiocarpal joint, midcarpal joint, carpometacarpal joints, dorsal radiocarpal ligament, compartments of extensor tendons, radial artery, cephalic vein, two small branches of the radial nerve: superficial and deep, as well as certain midcarpal ligaments, particularly the scapholunate ligament and lunotriquetral ligament. The paper was distinguished in 2014 as the “poster of the month” (poster number C-1896) during the poster session of the European Congress of Radiology in Vienna.

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.

Imaging of radial wrist pain. I. Imaging modalities and anatomy

Radial wrist pain is a common clinical complaint. The relatively complex anatomy in this region, combined with the small size of the anatomical structures and occasionally subtle imaging findings, can pose problems when trying to localize the exact cause of pain. To fully comprehend the underlying pathology, one needs a good understanding of both radial-sided wrist anatomy and the relative merits of the different imaging techniques used to assess these structures. In part I of this review, these aspects will be discussed.

Palpation versus ultrasound-guided corticosteroid injections and short-term effect in the distal radioulnar joint disorder: a randomized, prospective single-blinded study

The aim of this study was to conduct a randomized, prospective single-blinded clinical study on the mid-term benefits and accuracy rate of the ultrasound (US)-guided versus palpation-guided intra-articular (IA) injections for the treatment of distal radioulnar joint (DRUJ) disorder. Subjects with DRUJ disorder (n = 60) were randomly assigned to undergo US-guided or palpation-guided IA injection. Primary outcomes were measured with Disability of the Arm, Shoulder, and Hand questionnaire (DASH) and secondary outcomes included Verbal Numeric Pain Scale (VNS), Modified Mayo Wrist Score (MMWS), range of motion (ROM), and accuracy rate between two groups; 1.25 mL of mixed material (0.5 ml Omnipaque + 1 % lidocaine 0.25 ml + triamcinolone 20 mg 0.5 ml) was injected into the intra-articular space of the DRUJ. Treatment effects were assessed by using VNS, DASH, MMWS, and passive ROM of the DRUJ (supination, pronation from neutral) before the injections and at 1, 3, and 6 months after the injections. After the US-guided and palpation-guided IA injection into DRUJ, a radiographic image was taken to determine whether the injected material had reached the IA space or infiltrated into the soft tissue. US-guided IA injections showed significantly higher accuracy (100 %) than palpation-guided IA injections (75.8 %) in DRUJ. VNS, DASH, MMWS, and ROM were improved at 1, 3, and 6 months in both groups. There was no significant difference in clinical outcomes between the group receiving US-guided injections and the group receiving palpation-guided injections. US-guided IA injection showed significantly higher accuracy than palpation-guided IA injection in the DRUJ, and corticosteroid IA injections were effective in improving of the pain of patients with DRUJ disorder during 6 months of follow-up.

Ultrasound in hand and wrist: approach for a standardized examination

New very high-frequency ultrasound probes allow highly detailed imaging of superficial structures and thus are especially suitable for examination of the hand. For successful application, specific knowledge and experience as well as standardized examination techniques are required. Based on 11 determined sections of the flexor and extensor side of the hand, the authors present one approach to a standardized ultrasound examination allowing a quick view of all structures. An additional presentation of the most typical traumatic and degenerative disease patterns underlines the potency of this examination technique. With adequate equipment, training and expertise, ultrasound should be regarded as the first-line imaging modality for the assessment of a wide range of pathological conditions affecting the wrist and hand. An exact knowledge of the anatomical relation of the structures to each other gained from ultrasound experience is equally useful for following surgery of the cases.

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.

High-resolution ultrasound evaluation of extrinsic wrist ligaments in patients affected by rheumatoid arthritis

OBJECTIVES

To evaluate the ultrasound features of the extrinsic wrist ligaments in rheumatoid arthritis (RA) patients in comparison with healthy volunteers.

METHODS

Twenty-one consecutive patients affected by RA (12 men, 9 women; mean age 57 ± 14.6 years) were compared with 21 controls (12, 9; 54 ± 12.1, respectively). Wrists were evaluated using ultrasound on both palmar and dorsal sides along each ligament, using carpal bones as references. The following ligaments were studied: radioscaphocapitate, radiolunotriquetral, palmar ulnolunate, palmar ulnotriquetral, dorsal radiotriquetral, dorsal ulnotriquetral, and radial collateral ligament. Ligament number and thickness were noted. Echotexture was rated as fibrillar, fragmented, or heterogeneous; the surface was rated as smooth or blurred.

RESULTS

The number of palmar ulnolunate and palmar ulnotriquetral ligaments detected by ultrasound in patients was significantly lower than in controls (P = 0.031 and P = 0.037, respectively). All ligaments had significantly more fragmented or heterogeneous echotexture and blurred surface and were significantly thinner in patients than in controls (P < 0.001). No correlation was found between ligament thickness and RA duration or clinical parameters.

CONCLUSIONS

Extrinsic wrist ligaments were less detectable and thinner in patients affected by RA compared with healthy volunteers matched for age and sex. Ligament thinning did not directly correlate with RA duration and clinical parameters.

KEY POINTS

• Ultrasound is increasingly used to evaluate normal anatomy of extrinsic wrist ligaments. • Extrinsic wrist ligaments are thinner in rheumatoid arthritis patients than in controls. • Extrinsic wrist ligaments are less easy to detect in rheumatoid arthritis patients. • Ligament thinning and detectability are not related to clinical parameters.

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.

Effect of SonoVue on the synovial membrane in rabbit knees

OBJECTIVES

The purpose of this study was to evaluate the effect of intra-articular injection of SonoVue (sulfur hexafluoride with a phospholipid shell; Bracco SpA, Milan, Italy) on the synovial membrane in an animal model.

METHODS

Twenty-one New Zealand White rabbits (42 knees) were used in this study. We injected the knees with normal saline (saline group; n = 21) and SonoVue (SonoVue group; n = 21). A histologic examination of the knees was performed out at 3 and 12 hours and 3, 7, 15, 30, and 45 days after injection. Four histologic parameters (synovial hyperplasia, synovial stroma, vascular dilatation, and inflammatory infiltrates) were graded separately.

RESULTS

We found no significant differences in this study for synovial hyperplasia, vascular dilatation, or inflammatory infiltrates between the saline and SonoVue groups. A significant difference was only observed for synovial stroma (P < .05), and most of the histologic changes were mild in the saline group and moderate in the SonoVue group. The histologic changes observed in this study are considered transitory and reversible.

CONCLUSIONS

The results suggest that intra-articular injection of SonoVue is a safe procedure.