Diagnostic comparison of 1.5 Tesla and 3.0 Tesla preoperative MRI of the wrist in patients with ulnar-sided wrist pain

A Biomechanical Perspective on Distal Radioulnar Joint Instability

Background The purpose of this article was to review the anatomy, kinematics of the distal radioulnar joint (DRUJ), and to discuss definition, classification, and diagnosis of DRUJ instability. Methods A biomechanical perspective on physical examination of DRUJ ballottement test was documented. Physiological dynamic DRUJ translation and differences of the translation following sequential ligament sectioning and changes in different forearm and wrist positions were demonstrated. The clinical significance of each ligament's contribution to joint stability in specific wrist positions was addressed. Conclusion Each ligament stabilizing the DRUJ contributed to joint stability depending on the direction (palmer or dorsal) and different positions of the wrist and forearm. DRUJ ballottement test in each wrist and forearm position may detect tears of specific ligament stabilizing the DRUJ.

Classification of ulnar triangular fibrocartilage complex tears. A treatment algorithm for Palmer type IB tears

The classical definition of 'Palmer Type IB' triangular fibrocartilage complex tear, includes a spectrum of clinical conditions. This review highlights the clinical and arthroscopic criteria that enable us to categorize five classes on a treatment-oriented classification system of triangular fibrocartilage complex peripheral tears. Class 1 lesions represent isolated tears of the distal triangular fibrocartilage complex without distal radio-ulnar joint instability and are amenable to arthroscopic suture. Class 2 tears include rupture of both the distal triangular fibrocartilage complex and proximal attachments of the triangular fibrocartilage complex to the fovea. Class 3 tears constitute isolated ruptures of the proximal attachment of the triangular fibrocartilage complex to the fovea; they are not visible at radio-carpal arthroscopy. Both Class 2 and Class 3 tears are diagnosed with a positive hook test and are typically associated with distal radio-ulnar joint instability. If required, treatment is through reattachment of the distal radio-ulnar ligament insertions to the fovea. Class 4 lesions are irreparable tears due to the size of the defect or to poor tissue quality and, if required, treatment is through distal radio-ulnar ligament reconstruction with tendon graft. Class 5 tears are associated with distal radio-ulnar joint arthritis and can only be treated with salvage procedures. This subdivision of type IB triangular fibrocartilage complex tear provides more insights in the pathomechanics and treatment strategies.

LEVEL OF EVIDENCE

II.

Comparison of Median Nerve Cross-sectional Area on 3-T MRI in Patients With Carpal Tunnel Syndrome

This study correlated morphologic abnormalities of idiopathic carpal tunnel syndrome (CTS) with the severity of CTS using 3-T magnetic resonance imaging (MRI). The relationship of the severity of CTS and the cross-sectional area of the median nerve (CSA) was assessed at several levels. Seventy wrists of 35 patients (27 women and 8 men) with unilateral idiopathic CTS underwent nerve conduction study and 3-T MRI of the wrist. The CSA at 4 levels (distal radioulnar joint, body of scaphoid, tubercule of scaphoid, and hook of hamate) and the thickness of the transverse carpal ligament at 3 levels in both affected and unaffected hands were measured using 3-T MRI and correlated with the severity of CTS assessed with distal motor latency. The CSA in the affected hand at the scaphoid body level was significantly higher than in the unaffected hand. The CSA at the scaphoid body level was positively correlated with distal motor latency in the affected hand. The CSA in the affected hand at the scaphoid tubercule level was significantly lower than in the unaffected hand. The CSA had a negative correlation with distal motor latency at the scaphoid tubercule level. The CSA at the distal radioulnar joint and the hamate hook was not significantly different between the affected hand and the unaffected hand. The CSA at the distal radioulnar joint level and hook level were not correlated significantly with distal motor latency in the affected hand. The mean CSA of the affected hand at the scaphoid body level was highest in 4 levels. [Orthopedics. 2017; 40(1):e77-e81.].

High-Resolution 3T MR Imaging of the Triangular Fibrocartilage Complex

This study is intended as a review of 3Tesla (T) magnetic resonance (MR) imaging of the triangular fibrocartilage complex (TFCC). The recent advances in MR imaging, which includes high field strength magnets, multi-channel coils, and isotropic 3-dimensional (3D) sequences have enabled the visualization of precise TFCC anatomy with high spatial and contrast resolution. In addition to the routine wrist protocol, there are specific techniques used to optimize 3T imaging of the wrist; including driven equilibrium sequence (DRIVE), parallel imaging, and 3D imaging. The coil choice for 3T imaging of the wrist depends on a number of variables, and the proper coil design selection is critical for high-resolution wrist imaging with high signal and contrast-to-noise ratio. The TFCC is a complex structure and is composed of the articular disc (disc proper), the triangular ligament, the dorsal and volar radioulnar ligaments, the meniscus homologue, the ulnar collateral ligament (UCL), the extensor carpi ulnaris (ECU) tendon sheath, and the ulnolunate and ulnotriquetral ligaments. The Palmer classification categorizes TFCC lesions as traumatic (type 1) or degenerative (type 2). In this review article, we present clinical high-resolution MR images of normal TFCC anatomy and TFCC injuries with this classification system.

The "Four-Leaf Clover" Treatment Algorithm: A Practical Approach to Manage Disorders of the Distal Radioulnar Joint

Most symptomatic distal radioulnar joint (DRUJ) conditions result from derangements to several structures that may include the length, shape, and/or orientation of the articulating surfaces; the cartilage of the DRUJ and/or ulnocarpal joint; the DRUJ and/or ulnocarpal joint ligaments; and the extensor carpi ulnaris and/or pronator quadratus muscle. Once a complete diagnosis is made, often only one of these components is addressed, which results in suboptimal clinical outcomes. In this article, we present a treatment algorithm (the Four-Leaf Clover algorithm) to guide treatment of DRUJ pathology. The Four-Leaf Clover principle is a guiding algorithm, not a document forcing the surgeon to adopt one particular treatment. Its purpose is to provide treating physicians with a checklist that helps ensure that they do not miss any of the different components that need to be addressed for a complete treatment. Using the treatment algorithm, we should achieve satisfactory resolution of patients' symptoms after addressing the particular components in a stepwise approach.

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 performance of magnetic resonance imaging in the detection of triangular fibrocartilage complex injury: a meta-analysis

The aim of this study was to evaluate the accuracy of magnetic resonance imaging in the detection of triangular fibrocartilage complex injury through a meta-analysis. A comprehensive literature search was conducted before 1 April 2014. All studies comparing magnetic resonance imaging results with arthroscopy or open surgery findings were reviewed, and 25 studies that satisfied the eligibility criteria were included. Data were pooled to yield pooled sensitivity and specificity, which were respectively 0.83 and 0.82. In detection of central and peripheral tears, magnetic resonance imaging had respectively a pooled sensitivity of 0.90 and 0.88 and a pooled specificity of 0.97 and 0.97. Six high-quality studies using Ringler's recommended magnetic resonance imaging parameters were selected for analysis to determine whether optimal imaging protocols yielded better results. The pooled sensitivity and specificity of these six studies were 0.92 and 0.82, respectively. The overall accuracy of magnetic resonance imaging was acceptable. For peripheral tears, the pooled data showed a relatively high accuracy. Magnetic resonance imaging with appropriate parameters are an ideal method for diagnosing different types of triangular fibrocartilage complex tears.

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.

Diagnostic accuracy of 3.0 T magnetic resonance imaging for the detection of meniscus posterior root pathology

PURPOSE

The purpose of this study was to determine the diagnostic accuracy of 3 T MRI, including sensitivity, specificity, negative and positive predictive values, for detection of posterior medial and lateral meniscus root tears and avulsions.

METHODS

All patients who had a 3 T MRI of the knee, followed by arthroscopic surgery, were included in this study. Arthroscopy was considered the gold standard. Meniscus root tears diagnosed at arthroscopy and on MRI were defined as a complete meniscus root detachment within 9 mm of the root. All surgical data were collected prospectively and stored in a data registry. MRI exams were reported prospectively by a musculoskeletal radiologist and reviewed retrospectively.

RESULTS

There were 287 consecutive patients (156 males, 131 females; mean age 41.7 years) in this study. Prevalence of meniscus posterior root tears identified at arthroscopy was 9.1, 5.9% for medial and 3.5% for lateral root tears (one patient had both). Sensitivity was 0.770 (95% CI 0.570, 0.901), specificity was 0.729 (95% CI 0.708, 0.741), positive predictive value was 0.220 (95% CI 0.163, 0.257) and negative predictive value was 0.970 (95% CI 0.943, 0.987). For medial root tears, sensitivity was 0.824 (95% CI 0.569, 0.953), specificity was 0.800 (95% CI 0.784, 0.808), positive predictive value was 0.206 (95% CI 0.142, 0.238) and negative predictive value was 0.986 (95% CI 0.967, 0.996). For lateral meniscus posterior root tears, sensitivity was 0.600 (95% CI 0.281, 0.860), specificity was 0.903 (95% CI 0.891, 0.912), positive predictive value was 0.181 (95% CI 0.085, 0.261) and negative predictive value was 0.984 (95% CI 0.972, 0.994).

CONCLUSIONS

This study demonstrated moderate sensitivity and specificity of 3 T MRI to detect posterior meniscus root tears. The negative predictive value of 3 T MRI to detect posterior meniscus root tears was high; however, the positive predictive value was low. Sensitivity was higher for medial root tears, indicating a higher risk of missing lateral root tears on MRI. Imaging has an important role in identifying meniscus posterior horn root tears; however, some root tears may not be identified until arthroscopy.

LEVEL OF EVIDENCE

Prognostic study (diagnostic), Level II.

Prevalence of triangular fibrocartilage complex abnormalities regardless of symptoms rise with age: systematic review and pooled analysis

BACKGROUND

Triangular fibrocartilage complex abnormalities seem to be more common with age, but the degree to which this is so, and the degree to which the presence of an abnormality is associated with symptoms, are topics of controversy.

QUESTIONS/PURPOSES

We wished to perform a systematic review to determine the prevalence of triangular fibrocartilage complex abnormalities, and to determine if the prevalence of abnormalities are greater with increasing age. In addition, we stratified age groups based on symptoms.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Library through August 15, 2013. Studies that reported triangular fibrocartilage complex abnormalities by age were included. Fifteen studies including 977 wrists met our criteria and reported a total of 368 (38%) triangular fibrocartilage complex abnormalities. Eight studies included symptomatic patients; the remainder studied cadavers (six studies) or asymptomatic volunteers (one study). Patients were divided into four age groups (< 30, 30-49, 50-69, and 70 years and older) for pooled analysis, comparing the proportions of patients with and without abnormalities between groups using chi-square analysis. We also evaluated the proportions after stratifying each age group by symptoms.

RESULTS

Overall, the prevalence of triangular fibrocartilage complex abnormalities increased with age, from 27% (80/301) in patients younger than 30 years to 49% (130/265) in patients 70 years and older (p < 0.001), odds ratio (OR), 2.7, 95% CI, 1.9-3.8 (p < 0.001). In asymptomatic patients, triangular fibrocartilage complex prevalence abnormality increased from 15% (24/159) to 49% (129/263) in the same age groups (p < 0.001), OR, 5.4, 95% CI, 3.3-8.9 (p < 0.001). For symptomatic patients prevalence ranged from 39% (56/142) to 70% (14/20) in patients between 50 and 69 years old (p < 0.034), OR, 3.6, 95% CI, 1.3-9.9 (p < 0.014).

CONCLUSION

Triangular fibrocartilage complex abnormalities are common in symptomatic and asymptomatic wrists, and they are increasingly common with age. As in all situations where abnormalities are so common that they may be incidental, we need (1) a reliable and accurate method for determining whether these abnormalities are the cause of symptoms; and (2) evidence that treatment of these abnormalities improves symptoms better than placebo.

LEVEL OF EVIDENCE

Level III, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

Muscle-fat MRI: 1.5 Tesla and 3.0 Tesla versus histology

INTRODUCTION

We evaluated muscle/fat fraction (MFF) accuracy and reliability measured with an MR imaging technique at 1.5 Tesla (T) and 3.0T scanner strengths, using biopsy as reference.

METHODS

MRI was performed on muscle samples from pig and rabbit species (n = 8) at 1.5T and 3.0T. A chemical shift based 2-point Dixon method was used, collecting in-phase and out-of-phase data for fat/water of muscle samples. Values were compared with MFFs calculated from histology.

RESULTS

No significant difference was found between 1.5T and 3.0T (P values = 0.41-0.96), or between histology and imaging (P = 0.83) for any muscle tested.

CONCLUSIONS

RESULTS suggest that a 2-point Dixon fat/water separation MRI technique may provide reliable quantification of MFFs at varying field strengths across different animal species, and consistency was established with biopsy. The results set a foundation for larger scale investigation of quantifying muscle fat in neuromuscular disorders.

Distal radio-ulnar joint instability in children and adolescents after wrist trauma

This study retrospectively evaluated the medical records and radiographs of patients younger than aged 25 that were referred for a second opinion due to ulnar-sided wrist pain and persistent distal radio-ulnar (DRU) joint instability. We identified 85 patients with a major wrist trauma before the age of 18. Median age at trauma was 14 years. Median time between trauma and diagnosis of DRUJ instability was 3 years. Sixty-seven patients (79%) had sustained a fracture at the initial trauma. The two most common skeletal injuries related to the DRUJ instability were Salter-Harris type II fractures (24%) and distal radius fractures (19%). In 19 patients (22%), the secondary DRUJ instability was caused by malunion or growth arrest. Eighteen patients (21%) had no fracture; in spite of this, they presented with subsequent symptomatic DRUJ instability. Fourteen of these 18 patients had a triangular fibrocartilage complex (TFCC) tear, confirmed by arthroscopy, open surgery, or magnetic resonance imaging. In conclusion, late DRUJ instability due to wrist fractures or isolated TFCC tears was found to be common in children and adolescents.

LEVEL OF EVIDENCE

IV.

Intraobserver and interobserver variability in diagnosing scapholunate dissociation by cineradiography

PURPOSE

To evaluate the intraobserver and interobserver variability in diagnosing scapholunate dissociation (SLD) by wrist cineradiography.

METHODS

A musculoskeletal radiologist, hand surgeon, and trauma surgeon assessed the records of 50 consecutive wrist cineradiographies performed in 25 patients. Fluoroscopy was performed on the unaffected and affected wrist and consisted of radiographer-controlled passive flexion-extension and passive radial-ulnar deviation in both posteroanterior and lateral projections. To determine the intraobserver variability, the 3 reviewers reassessed all wrist cineradiographies 6 months after their first assessment. The kappa coefficient for interobserver agreement was calculated using the jackknife method. The Cohen kappa was used to assess intraobserver variability.

RESULTS

The interobserver variability for diagnosing SLD by cineradiography was excellent (κ = 0.84). The intraobserver variability for the hand surgeon was excellent (κ = 0.80), and was good for the radiologist (κ = 0.72) and the trauma surgeon (κ = 0.76).

CONCLUSIONS

Cineradiography is a promising and helpful, noninvasive tool for diagnosing SLD. It is widely available and has relatively low costs. Conventional radiographs remain essential in the primary workup for suspected SLD. However, we recommend cineradiography when an SLD is clinically suspected.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

The diagnostic accuracy of wrist cineradiography in diagnosing scapholunate dissociation

Ruptures of the scapholunate ligament (SLL) may cause carpal instability, also known as scapholunate dissociation (SLD). SLD may lead to osteoarthritis of the radiocarpal and midcarpal joints. The aim of this retrospective study was to determine the diagnostic value of wrist cineradiography in detecting SLD. All cineradiographic studies made during a 24 year period were retrieved. All patients who underwent the confirmation method (arthroscopy and/or arthrotomy) and cineradiography were included. In total, 84 patients met the inclusion criteria. Sensitivity, specificity, likelihood ratio, positive predictive value, negative predictive value, and diagnostic accuracy for detecting SLD were calculated for radiography and cineradiography. Cineradiography had a sensitivity of 90%, a specificity of 97%, and a diagnostic accuracy of 0.93 in detecting SLD. Radiography had a sensitivity of 81%, a specificity of 80%, and a diagnostic accuracy of 0.81. Cineradiography has a high diagnostic value for diagnosing SLDs. A positive cineradiography markedly increases the post-test probability of SLD.

MRI of wrist ligaments

The optimal imaging protocols for magnetic resonance imaging (MRI) of the wrist ligaments are discussed, including the use of magnetic resonance arthrography, and 3 Tesla (T) versus 1.5 T magnetic field strength. The normal MRI appearance of the triangular fibrocartilage complex, capsular, and interosseous wrist ligaments is briefly covered to point out potential diagnostic pitfalls. Numerous examples of common ligamentous pathology discernible on MRI are provided, along with the latest estimates of diagnostic sensitivity and specificity provided by the literature.

Utility of magnetic resonance imaging for detection of longitudinal split tear of the ulnotriquetral ligament

PURPOSE

Wrist magnetic resonance imaging (MRI) has established utility in the diagnosis of wrist ligament tears, including complete tears of the ulnotriquetral ligament (UTL) and other components of the triangular fibrocartilage complex. A new type of longitudinal split tear of the UTL has recently been described with no imaging correlate. Our aims were to describe putative MRI findings associated with longitudinal UTL split tears and to assess diagnostic accuracy.

METHODS

We randomly selected 40 patients with arthroscopically proven longitudinal UTL split tears and 20 patients with intact UTLs, all of whom had preoperative 3 T MRI of the same wrist performed, from a list of operative notes spanning from January 1997 through October 2011, filtered with the terms "ulnotriquetral ligament" and "ulnar triquetral ligament." Two musculoskeletal radiologists who were blinded to surgical results and clinical information independently reviewed the exams. They recorded the degree of certainty of whether a longitudinal UTL split tear was present and whether several other hypothesized associated abnormalities were present.

RESULTS

Overall sensitivity for definitive longitudinal UTL split tear detection on MRI was 58% for reader 1 and 30% for reader 2. Specificity was 60% for both. There were no statistically significant discriminatory findings.

CONCLUSIONS

Among a selected group of patients who all had wrist arthroscopy, preoperative noncontrast 3 T wrist MRI had poor sensitivity and specificity for detection of the longitudinal split type of UTL tear. To date, MRI may be more helpful to exclude potential alternative diagnoses in the patient with ulnar wrist pain.

Reconstructed animation from four-phase grip MRI of the wrist with ulnar-sided pain

In order to visualize dynamic variations related to ulnar-sided wrist pain, animation was reconstructed from T2* coronal-sectioned magnetic resonance imaging in each of the four phases of grip motion for nine wrists in patients with ulnar pain. Eight of the nine wrists showed a positive ulnar variance of less than 2 mm. Ulnocarpal impaction and triangular fibrocartilage complex injury were assessed on the basis of animation and arthroscopy, respectively. Animation revealed ulnocarpal impaction in four wrists. In one of the four wrists, the torn portion of the articular disc was impinged between the ulnar head and ulnar proximal side of the lunate. In another wrist, the ulnar head impacted the lunate directly through the defect in the articular disc that had previously been excised. An ulnar shortening osteotomy successfully relieved ulnar wrist pain in all four cases with both ulnocarpal impaction and Palmer's Class II triangular fibrocartilage complex tears. This method demonstrated impairment of the articular disc and longitudinal instability of the distal radioulnar joint simultaneously and should be of value in investigating dynamic pathophysiology causing ulnar wrist pain.

Isolated lunotriquetral ligament tears treated with ulnar shortening osteotomy

PURPOSE

To evaluate outcomes in a single-surgeon series of ulnar shortening osteotomy for the treatment of traumatic isolated tears to the lunotriquetral interosseous ligament (LTIL).

METHODS

This study includes 53 consecutive cases of posttraumatic isolated LTIL tears treated with ulnar shortening osteotomy with minimum 1-year follow-up (range, 1.0-10.6 y). We confirmed all LTIL tears via arthroscopy before performing a precision 2.5-mm oblique osteotomy using a modified Rayhack technique. We assessed outcomes using grip strength measurements and Chun and Palmer's modified Gartland Werley wrist scoring system, which includes subjective and objective outcome measures.

RESULTS

Preoperatively, 45 cases were graded as fair (28%; n = 15) or poor (57%; n = 30) on the modified Gartland Werley score. There were insufficient data to calculate grades in 8 cases (15%). At final follow-up, most patients exhibited excellent (51%; n = 27) or good (32%; n = 17) scores, some scored fair (17%; n = 9), and none scored as poor. All subjective and objective variables significantly improved over a mean follow-up of 36 months (range, 12-127 mo). Mean grip strength increased from a value of 23 kg before surgery to 33 kg over the same period, a 41% increase. All patients achieved clinical and radiographic union by 10 months. Osteotomy plates were removed routinely in most cases (89%; n = 47) at a mean of 17 months.

CONCLUSIONS

Ulnar shortening osteotomy reduced symptoms of posttraumatic isolated LTIL tears in this single-surgeon series.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Treatment with or without internal fixation for ulnar styloid base fractures accompanied by distal radius fractures fixed with volar locking plate

The purpose of this study was to evaluate the treatment results, with and without internal fixation of ulnar styloid base fractures associated with acute distal radius fractures. A total of 48 patients were enrolled, including 20 patients treated by internal fixation (fixation group) and 28 treated without internal fixation (non-fixation group). The evaluated parameters were postoperative range of motion, grip strength, DASH score, and the presence or absence of ulnar wrist pain over time. The outcome was assessed as "excellent" in 15 patients of the fixation group and 21 patients of the non-fixation group, and "good" in five patients of the fixation group and seven patients of the non-fixation group. There were no significant differences in the clinical outcomes or any of the parameters at the final evaluation between the two groups. However, the grip strength was significantly better in the non-fixation group than in the fixation group until 12 weeks postoperatively. The overall clinical outcome was good in both groups, with no significant difference between the groups.

Perilunate dislocations and fracture dislocations

Perilunate dislocations and fracture dislocations are high-energy injuries that can result in pain, stiffness, weakness, or disability if inappropriately treated. Prompt recognition and surgical treatment with anatomic reduction of carpal malalignment improve the likelihood of optimal, long-term clinical success and patient satisfaction. The progressive development of radiographic evidence of arthrosis is common but has not been shown to consistently correlate with worse patient function and outcomes.

Clinical and non-clinical aspects of distal radioulnar joint instability

Untreated distal radioulnar joint (DRUJ) injuries can give rise to long lasting complaints. Although common, diagnosis and treatment of DRUJ injuries remains a challenge. The articulating anatomy of the distal radius and ulna, among others, enables an extensive range of forearm pronosupination movements. Stabilization of this joint is provided by both intrinsic and extrinsic stabilizers and the joint capsule. These structures transmit the load and prevent the DRUJ from luxation during movement. Several clinical tests have been suggested to determine static or dynamic DRUJ stability, but their predictive value is unclear. Radiologic evaluation of DRUJ instability begins with conventional radiographs in anterioposterior and true lateral view. If not conclusive, CT-scan seems to be the best additional modality to evaluate the osseous structures. MRI has proven to be more sensitive and specific for TFCC tears, potentially causing DRUJ instability. DRUJ instability may remain asymptomatic. Symptomatic DRUJ injuries treatment can be conservative or operative. Operative treatment should consist of restoration of osseous and ligamenteous anatomy. If not successful, salvage procedures can be performed to regain stability.

Diagnostic accuracy of magnetic resonance imaging and magnetic resonance arthrography for triangular fibrocartilaginous complex injury: a systematic review and meta-analysis

BACKGROUND

Triangular fibrocartilaginous complex (TFCC) tears are common sources of ulnar-sided wrist pain and resultant functional disability. Diagnosis is based on the history and clinical examination as well as radiographic evidence of a TFCC central perforation or a radial/ulnar tear. The purpose of this study was therefore to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA) in the detection of TFCC injury in the adult population.

METHODS

Published and unpublished literature databases were searched. Two-by-two tables were constructed to calculate the sensitivity and specificity of MRI or MRA investigations against arthroscopic outcomes. Pooled sensitivity and specificity values and summary receiver operating characteristic curve evaluations were performed. The methodological quality of each study was assessed with use of the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) tool.

RESULTS

Twenty-one studies were included in the review, and these series included a total of 982 wrists. On meta-analysis, MRA was superior to MRI in the investigation of full-thickness TFCC tears, with a pooled sensitivity of 0.75 and a pooled specificity of 0.81 for MRI compared with 0.84 and 0.95, respectively, for MRA. MRA and MRI performed at greater field strengths were reported to have greater sensitivity and specificity than those performed at lower field strengths. There were insufficient data to assess the diagnostic test accuracy for partial-thickness TFCC tears.

CONCLUSIONS

Given its acceptable diagnostic test accuracy, it is recommended that MRA, rather than MRI, be performed in when there are questions about the diagnosis and subsequent management of patients with ulnar-sided wrist pain.

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.

Provocative wrist tests and MRI are of limited diagnostic value for suspected wrist ligament injuries: a cross-sectional study

QUESTION

What is the diagnostic value of provocative wrist tests and magnetic resonance imaging (MRI) for suspected wrist ligament injuries?

DESIGN

Cross-sectional study.

PARTICIPANTS

105 people presenting to hand clinics with wrist pain and suspected wrist ligament injuries were evaluated prospectively.

OUTCOME MEASURES

The integrity of wrist ligaments was tested with seven provocative tests. The results were compared to the reference standard of arthroscopy. In a subgroup of 55 participants, MRI findings were also compared to arthroscopy. The provocative tests were the scaphoid shift test (SS test), lunotriquetral test (LT test), midcarpal test (MC test), distal radioulnar joint test (DRUJ test), triangular fibrocartilage complex (TFCC) stress test (TFCC test), TFCC stress test with compression (TFCC comp test), and the gripping rotatory impaction test (GRIT).

RESULTS

Most provocative tests and MRI findings were of little or no value for diagnosing wrist ligament injuries. Exceptions were the SS test (+ve LR 2.88 and -ve LR 0.28), MC test (+ve LR 2.67) and DRUJ test (-ve LR 0.30), all of which were of mild diagnostic usefulness. MRI was moderately useful for diagnosing TFCC injuries (+ve LR 5.56, -ve LR 0.15), and was mildly useful for diagnosing scapholunate (SL) ligament injuries (+ve LR 4.17, -ve LR 0.32) and lunate cartilage damage (+ve LR 3.67, -ve LR 0.33). Adding MRI to provocative tests improved the accuracy of diagnosis of TFCC injuries slightly (by 13%) and lunate cartilage damage (by 8%).

CONCLUSION

Provocative wrist tests of SL ligament injuries and midcarpal ligament injuries are mildly useful for diagnosing wrist injuries. MRI diagnostic findings of SL ligament injuries, lunate cartilage damage, and TFCC are mildly to moderately useful. MRI slightly improves the diagnosis of TFCC injury and lunate cartilage damage compared to provocative tests alone.

Prevalence of triangular fibrocartilage complex abnormalities on MRI scans of asymptomatic wrists

PURPOSE

Magnetic resonance imaging (MRI) of the wrist is increasingly used in the diagnosis of ulnar-sided wrist pain; however, its efficacy in this setting still needs clarification. The purposes of this study were to investigate the prevalence of abnormal MRI findings in the triangular fibrocartilage complex (TFCC) in asymptomatic volunteers and to provide the clinician with comparative data when interpreting MRI results.

METHODS

A total of 103 asymptomatic volunteers underwent imaging of the wrist using a 1.9-T MR scanner and a send-receive birdcage quadrature coil. The images were evaluated by 3 independent interpreters, 2 musculoskeletal radiologists, and 1 orthopedic hand surgeon. We noted details regarding the TFCC morphology and the presence, characteristics, and location of any TFCC abnormality.

RESULTS

The TFCC was considered abnormal in 39 wrists. The scans were abnormal in 31 subjects younger than 50 years of age, in 5 subjects 50 to 59 years of age, and in all subjects older than 60 years of age (3 subjects). We diagnosed a complete tear of the TFCC in 23 wrists. An increase in age was correlated with an abnormal TFCC (r(pb) = 0.23; P = .016).

CONCLUSIONS

The prevalence of incidental TFCC findings in MRI scans of asymptomatic subjects is high. The presence of an abnormal TFCC on MRI may be of questionable clinical meaning, because there is a high incidence of TFCC abnormalities in asymptomatic subjects, particularly those over the age of 50. Imaging results must be viewed in the context of the clinical history and physical examination.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Subluxation of the distal radioulnar joint as a predictor of foveal triangular fibrocartilage complex tears

PURPOSE

The triangular fibrocartilage complex (TFCC) with its ulnar foveal attachment is the primary stabilizer of the distal radioulnar joint (DRUJ). The purpose of this study was to describe a technique for measuring the degree of subluxation of the DRUJ in wrist magnetic resonance imaging (MRI) examinations to predict tears involving the foveal attachment of the TFCC.

METHODS

We measured DRUJ geometry in wrist MRI examinations of 34 patients who were found to have foveal TFCC tears at surgery. We compared the results with DRUJ geometry in 11 asymptomatic controls. Subluxation of the ulnar head was assessed using transaxial MRI images obtained at the level of the DRUJ with the wrist in pronation. We quantified subluxation with a line spanning the sigmoid notch of the radius and a perpendicular line through the center of curvature of the articulating surface of the ulna. We calculated the ratio of the lengths of the dorsal and volar segments and normalized it to the center of the sigmoid notch.

RESULTS

A total of 34 patients with intraoperatively confirmed tears of the foveal attachment of the TFCC had a mean dorsal ulnar subluxation measurement of 16% ± 4%, whereas the 11 controls had a mean subluxation measurement of 5% ± 4%.

CONCLUSIONS

The results confirm the hypothesis that subluxation of the ulnar head relative to the sigmoid notch of the radius, as assessed by MRI with the wrist in pronation, is a predictor of tears of the foveal attachment of the TFCC.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Direct MR arthrography of cadaveric wrists: comparison between MR imaging at 3.0T and 7.0T and gross pathologic inspection

PURPOSE

To prospectively evaluate the diagnostic accuracy of magnetic resonance (MR) arthrography for the detection of articular cartilage abnormalities at 3.0T and 7.0T in cadaveric wrists.

MATERIALS AND METHODS

MR imaging (MRI) was performed in nine cadaveric wrists (four right wrists, five left; mean age, 81.0 ± 9.8 years) after the intraarticular administration of gadoterate-meglumine. A 3.0T and 7.0T MR system, mechanically identical custom-built 8-channel wrist coil arrays and a similar standard MRI protocol, were used. MR images were evaluated for visibility of articular cartilage surfaces, presence of cartilage lesions, and confidence of diagnosis by two independent radiologists. Open pathologic inspection served as reference standard. Sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV), and accuracy (ACC) were calculated. Wilcoxon signed rank test was used to assess differences in the diagnostic performance.

RESULTS

Visibility of articular cartilage surfaces was significantly better at 3.0T than at 7.0T (P < 0.001). Mean sensitivity, specificity, NPV, PPV, ACC for both readers were 63%, 90%, 85%, 76%, 82% at 3.0T, respectively, and 52%, 91%, 82%, 75%, 79% at 7.0T. The difference between 3.0T and 7.0T was not significant for reader 1 (P = 0.51), but was significant for reader 2 (P = 0.01). The level of confidence was significantly higher at 3.0T than at 7.0T for both readers (P = 0.004; P = 0.03).

CONCLUSION

MR arthrography of the wrist at 7.0T is still limited by the lack of commercially available radiofrequency coils and limited experience in sequence optimization, resulting in a significantly lower visibility of anatomy, lower diagnostic accuracy, and level of confidence in judging cartilage lesions compared to 3.0T.

Imaging of the wrist at 1.5 Tesla using isotropic three-dimensional fast spin echo cube

PURPOSE

To compare three-dimensional fast spin echo Cube (3D-FSE-Cube) with conventional 2D-FSE in MR imaging of the wrist.

MATERIALS AND METHODS

The wrists of 10 volunteers were imaged in a 1.5 Tesla MRI scanner using an eight-channel wrist coil. The 3D-FSE-Cube images were acquired in the coronal plane with 0.5-mm isotropic resolution. The 2D-FSE images were acquired in both coronal and axial planes for comparison. An ROI was placed in fluid, cartilage, and muscle for SNR analysis. Comparable coronal and axial images were selected for each sequence, and paired images were randomized and graded for blurring, artifact, anatomic details, and overall image quality by three blinded musculoskeletal radiologists.

RESULTS

SNR of fluid, cartilage and muscle at prescribed locations were higher using 3D-FSE-Cube, without reaching statistical significance. Fluid-cartilage CNR was also higher with 3D-FSE-Cube, but not statistically significant. Blurring, artifact, anatomic details, and overall image quality were significantly better on coronal 3D-FSE-Cube images (P < 0.001), but significantly better on axial 2D-FSE images compared with axial 3D-FSE-Cube reformats (P < 0.01).

CONCLUSION

Isotropic data from 3D-FSE-Cube allows reformations in arbitrary scan planes, which may make multiple 2D acquisitions unnecessary, and improve depiction of complex wrist anatomy. However, axial reformations suffer from blurring, likely due to T2 decay during the long echo train, limiting overall image quality in this plane.

Radial side (1D) tears

The triangular fibrocartilage complex (TFCC) is the key structure at the wrist that facilitates the rotation of the radius and the carpus on the distal ulnar. The radial or type 1D tears of the TFCC are uncommon, but they pose a major disruption of the articular contact between the carpus and the distal ulna. The tears can heal by arthroscopically repairing the TFCC back to the radius using sutures through bone tunnels. This procedure allows patients to return to their work and sports activities with significant recovery of strength and range of motion.

Longitudinal split tears of the ulnotriquetral ligament

Unlike tears of the peripheral triangular fibrocartilage or avulsions of the distal radioulnar ligaments, longitudinal split tears of the ulnotriquetral (UT) ligament do not cause any instability to the distal radioulnar joint or the ulnocarpal articulation. It is mainly a pain syndrome that can be incapacitating. However, because the UT ligament arises from the palmar radioulnar ligament of the triangular fibrocartilage complex (TFCC), it is by definition, an injury of the TFCC. The purpose of this article is to describe the cause of chronic ulnar wrist pain arising from a longitudinal split tear of the UT ligament.

Arthroscopic and open repair of the TFCC

Injury to the triangular fibrocartilage complex is the most common cause of ulnar-sided wrist pain. This functionally related complex of anatomic structures can be a source of pain secondary to acute injury or chronic degeneration. Strategies for the treatment of these injuries involve determining the anatomic location of the tear, the presence of associated distal radioulnar joint instability, and the presence of associated degenerative changes. Surgical management with open and arthroscopic techniques have been described, both with successful results.

Imaging the distal radioulnar joint

Imaging the DRUJ requires knowledge of the complex bony, muscular, and ligamentous anatomy that contribute to this unique joint. Standard well-positioned radiography is always the appropriate first step in any imaging evaluation of the wrist. High-resolution MRI of the wrist, preferably performed at 3T, helps to delineate the important ligamentous structures relevant to the DRUJ and ulnar wrist, whether the joint is unstable or not. The presence of instability on physical examination is an indication for dynamic CT evaluation. Close attention to technique, no matter what the modality of choice, offers the best chance for success in providing added value with imaging. Finally, communication between the radiologist and hand surgeon allows the advanced imaging examinations to be tailored to the specific clinical problem for the most effective use of resources for each individual patient.

MRI of the wrist at 7 tesla using an eight-channel array coil combined with parallel imaging: preliminary results

PURPOSE

To determine the feasibility of performing MRI of the wrist at 7 Tesla (T) with parallel imaging and to evaluate how acceleration factors (AF) affect signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and image quality.

MATERIALS AND METHODS

This study had institutional review board approval. A four-transmit eight-receive channel array coil was constructed in-house. Nine healthy subjects were scanned on a 7T whole-body MR scanner. Coronal and axial images of cartilage and trabecular bone micro-architecture (3D-Fast Low Angle Shot (FLASH) with and without fat suppression, repetition time/echo time = 20 ms/4.5 ms, flip angle = 10 degrees , 0.169-0.195 x 0.169-0.195 mm, 0.5-1 mm slice thickness) were obtained with AF 1, 2, 3, 4. T1-weighted fast spin-echo (FSE), proton density-weighted FSE, and multiple-echo data image combination (MEDIC) sequences were also performed. SNR and CNR were measured. Three musculoskeletal radiologists rated image quality. Linear correlation analysis and paired t-tests were performed.

RESULTS

At higher AF, SNR and CNR decreased linearly for cartilage, muscle, and trabecular bone (r < -0.98). At AF 4, reductions in SNR/CNR were:52%/60% (cartilage), 72%/63% (muscle), 45%/50% (trabecular bone). Radiologists scored images with AF 1 and 2 as near-excellent, AF 3 as good-to-excellent (P = 0.075), and AF 4 as average-to-good (P = 0.11).

CONCLUSION

It is feasible to perform high resolution 7T MRI of the wrist with parallel imaging. SNR and CNR decrease with higher AF, but image quality remains above-average.

Windows on the human body--in vivo high-field magnetic resonance research and applications in medicine and psychology

Analogous to the evolution of biological sensor-systems, the progress in "medical sensor-systems", i.e., diagnostic procedures, is paradigmatically described. Outstanding highlights of this progress are magnetic resonance imaging (MRI) and spectroscopy (MRS), which enable non-invasive, in vivo acquisition of morphological, functional, and metabolic information from the human body with unsurpassed quality. Recent achievements in high and ultra-high field MR (at 3 and 7 Tesla) are described, and representative research applications in Medicine and Psychology in Austria are discussed. Finally, an overview of current and prospective research in multi-modal imaging, potential clinical applications, as well as current limitations and challenges is given.

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.

Detection of in vivo dynamic 3-D motion patterns in the wrist joint

We present a method for measurement dynamic in vivo carpal motion patterns. The method consists of a 4-D rotational X-ray (RX) with improved image quality and image processing for accurate detection in vivo wrist motion measurements. Dynamic 3-D imaging yields a number of volume reconstructions of the wrist at different phases of its cyclic motion. Next, the carpal reconstructions are registered to their static acquired and segmented counterpart in all phases. With this information, the relation between the applied motion and carpal kinematic behavior is acquired, i.e., the motion patterns. We investigated the precision of the image acquisition and processing and tested it on three healthy subjects. The precision of the image acquisition and image processing is in the range of submillimeters and subdegrees, respectively, which is better than existing systems and sufficient for clinical investigations. Reproducibility measurements show some more deviation ( > 1 degrees). This method was tested on four human volunteers and agrees for the greater part with previously done invasive and nondynamic measurements. In vivo motion pattern measurement with 4-D-RX imaging and processing is accurate and noninvasive. The motion patterns can reveal disorders that could not have been detected in either video fluoroscopy, computed tomography, or MRI.