Gamekeeper thumb: comparison of MR arthrography with conventional arthrography and MR imaging in cadavers

Acute Thumb Metacarpophalangeal Joint Ulnar Collateral Ligament Injury: Diagnosis, Management, and Return to Sports Considerations

ABSTRACT

Thumb metacarpophalangeal joint ulnar collateral ligament injuries are common in athletes and range from mild sprains to complete retracted tears. The typical injury mechanism of a valgus force directed onto an abducted or extended thumb is frequently seen in certain sporting activities, such as skiing, football, and baseball. Ultrasound and magnetic resonance imaging are excellent imaging supplements to the clinical evaluation for diagnosis confirmation. Positive treatment outcomes have been demonstrated when these injuries are appropriately managed both nonoperatively and surgically. When deciding on a treatment plan, it is paramount to take the athlete's injury severity and sport-specific factors into account. The aim of this review is to summarize the sport epidemiology, diagnosis, treatment options, and return to play considerations for athletes who sustain an acute thumb metacarpophalangeal joint ulnar collateral ligament injury.

The Accuracy and Cost-Effectiveness of MRI Assessment of Collateral Ligament Injuries of the Lesser Digits’ Proximal Interphalangeal Joints

Background

Collateral ligament injuries of the thumb and lesser digits are simple injuries, but they may lead to disabilities in hand function. This study aimed to evaluate the accuracy and cost-effectiveness of magnetic resonance imaging (MRI) in diagnosing proximal interphalangeal (PIP) collateral ligament injuries of lesser digits.

Methods

A retrospective evaluation was conducted on 18 fingers that had undergone surgery for PIP joint complete collateral ligament injury. Pre-operative MRI results were compared with the intra-operative findings. The data from MRI and direct intraoperative findings were analyzed by the Chi-square test in paired groups. The McNemar test analyzed the accuracy of the MRI test for detecting volar plate injuries. Statistical Packages for Social Sciences (SPSS) version 25 (IBM Inc., Armonk, New York) software program was used for the analysis. 

Results

In digits other than the thumb, the accuracy of MRI for detecting collateral injuries was 38.89%, and detection was incorrect in 11 (61.11%) of 18 patients. There are significant differences between MRI and Intraoperative results (p<0.001). MRI findings for seven fingers (38.89%) of the 18 fingers involved were compatible with the surgery results (38.88%). By comparison, the MRI findings of 11 fingers (61.11%) were inconsistent with the intra-operative results. Eight patients (44.44%) were diagnosed preoperatively with MRI as having volar plate ruptures, three patients (16.67%) were diagnosed with open surgery, but only three of the volar plate diagnosed patients with MRI were verified as ruptures during open surgery (38.0%). In addition, preoperatively undetected volar plate injuries by MRI (n=10) were detected intra-operatively in three cases (30.0%). Therefore, the accuracy of MRI was found not to be statistically significant for the detection of volar plate injuries (p=0.727).

Conclusion

This study concluded that a 1.5-Tesla MRI with a slice thickness of 2-3 mm should not be relied on as a decisive tool for diagnosing collateral ligament injuries of the PIP joint of the lesser digits. Additionally, MRI was found insufficient for diagnosing volar plate injuries that accompanied collateral ligament injuries. Given these findings, one might conclude that MRI is not cost-effective in diagnosing collateral ligament injuries of the lesser digits PIP joint.

Efficiency of magnetic resonance imaging for diagnosing unstable ligament injuries around the thumb metacarpophalangeal joint: A comparison to arthroscopy

PURPOSE

This study aimed to assess the accuracy of MRI in identifying ulnar collateral ligament (UCL), radial collateral ligament (RCL), and volar plate (VP) injuries of the metacarpophalangeal joint (MCPJ) of the thumb by comparing with diagnostic arthroscopy.

METHODS

A total of 56 consecutive patients (56 thumbs) who underwent arthroscopy of MCPJ of thumb were enrolled. MRI findings reviewed by consensus reading of two blinded radiologists were compared with arthroscopic examination. Statistical data, including sensitivity, specificity, accuracy, were analyzed. Additionally, the performance characteristics between 3.0-tesla (39 thumbs) and 1.5-tesla (17 thumbs) MRI and acute (≤4 weeks after injury) and chronic (>4 weeks) injuries were compared.

RESULTS

Of the 56 thumbs, 38 thumbs (67.9%) showed complete correspondence between MRI and arthroscopic findings. The sensitivity, specificity and accuracy of MRI for detecting UCL injuries were 78.8%, 87.0%, and 82.1%, respectively. The sensitivity, specificity and accuracy of MRI for detecting RCL injuries were 85.7%, 91.4%, and 85.7%, respectively. The sensitivity, specificity, and accuracy of MRI for detecting VP injuries were 89.5%, 89.2%, and 81.0%, respectively. 3.0-tesla MRI showed higher correspondence with arthroscopic observation (76.9%) than 1.5-tesla MRI (47.1%) (p = 0.028). For acute injuries, 78.4% showed complete correspondence between MRI and arthroscopic findings, whereas 47.4% with chronic injuries revealed complete agreement (p = 0.019).

CONCLUSION

Overall, MRI is moderately effective in evaluating ligamentous lesions around MCPJ of thumb, but MRI is more sensitive in diagnosing acute injuries. Furthermore, 3.0-tesla MRI can provide results with better accuracy for diagnosing ligamentous lesions around MCPJ of thumb. However, the sensitivity and the specificity are not applicable to all ligament injuries, but only the severe one which would agree for surgical options.

Accuracy of Ultrasound Compared to Magnetic Resonance Imaging in the Diagnosis of Thumb Ulnar Collateral Ligament Injuries: A Prospective Case Series

This prospective case series compared the accuracy of ultrasound (US) to magnetic resonance imaging (MRI) in differentiating complete displaced (CD) thumb ulnar collateral ligament (UCL) tears from nondisplaced injuries in 10 patients with suspected traumatic thumb UCL injuries. Ultrasound identified 100% (2 of 2) of MRI-documented CD tears, both of which were further confirmed during surgical repair. Ultrasound identified the absence of CD tears in the remaining 8 patients. Although MRI is the reference standard imaging modality for characterizing thumb UCL injuries, ultrasound should be considered an accurate, cost-effective, and alternative imaging modality to differentiate surgical versus nonsurgical thumb UCL injuries.

Variation in the Rate of Surgery for Ulnar Collateral Ligament Injury of the Metacarpophalangeal Joint of the Thumb

BACKGROUND

The indications for repair of rupture of the ulnar collateral ligament (UCL) of the metacarpophalangeal (MP) joint of the thumb are debated. We studied factors predictive of operative treatment.

METHODS

In this retrospective study, we queried the research database from 3 affiliated urban hospitals in a single city in the United States and identified 383 patients with a thumb MP UCL injury. We recorded age, sex, treating surgeon, and whether or not a magnetic resonance imaging (MRI) was ordered. If radiographs showed a concomitant avulsion fracture, we measured fragment size and displacement. Multivariable logistic regression was used to identify factors independently associated with surgery.

RESULTS

Surgery was independently associated with older patient age, widely displaced fractures (≥2 mm), and obtaining an MRI. Two specific surgeons were less likely to operate. Compared with patients without a fracture, fractures without displacement were less likely to have surgery.

CONCLUSIONS

The rate of surgery for acute thumb MP UCL injury varies based on patient characteristics and the individual treating surgeon. Variation might decrease with improved diagnostic techniques and consideration of practice guidelines. Future studies are needed to determine the patients and injuries that will benefit most from surgery.

Thumb Injuries in Athletes

Thumb injuries are common in athletes and present a challenging opportunity for upper extremity physicians. Common injuries include metacarpal base fractures (Bennett and Rolando types), ulnar and radial collateral ligament injuries, dislocation of the carpometacarpal and metacarpophalangeal joints, and phalanx fractures. This review, although not exhaustive, highlights some of the most common thumb injuries in athletes. The treating physician must balance pressure from athletes, parents, coaches, and executives to expedite return to play with the long-term well-being of the athlete. Operative treatment may expedite return to play; however, one must carefully weigh the added risks involved with surgical intervention.

Thumb collateral ligament injuries in the athlete

PURPOSE OF REVIEW

The purpose of this review is to identify current principles in the diagnosis and treatment of collateral ligament injuries of the thumb in the athlete.

RECENT FINDINGS

Cadaver studies have clearly identified the ulnar and radial collateral ligaments origin and insertion footprints for repair or reconstruction. Ulnar and radial collateral ligament injuries are common in athletics. History and physical examination are paramount in determining partial versus complete tear. When surgical treatment is indicated, placing the repair/reconstruction in the anatomic footprint restores stability while maintaining motion. The senior author's preferred techniques are reported.

Clinical evaluation vs magnetic resonance imaging of the skier's thumb: A prospective cohort of 30 patients

INTRODUCTION

A skiers thumb, or a partial or complete rupture of the ulnar collateral ligament (UCL) is a clinical diagnosis. Swelling, pain, natural left-right difference and inexperience of a young physician can cause difficulty to correctly diagnose this injury. However, our theory is that any physician, given the correct instructions, should be able to diagnose this injury solely on clinical findings, without the necessity of additional imaging.

MATERIAL AND METHODS

In a large Dutch teaching hospital, physicians (residents with working experience of 6months-3years) working at the ER received instructions for physical examination. Patients >18 years, with an injury <1 week old, suspected of a true skier's thumb had an MRI reported by two independent radiologists to confirm the diagnosis.

RESULTS

Thirty patients were included. Seven patients had no fixed endpoint (23%), all had a complete ligamentous rupture of the UCL on MRI, of which three patients had a Stener lesion. Fifteen patients (50%) met with the criteria  >35° laxity in extension of MCP/ >20° laxity in 30° flexion of the MCP. Of these, thirteen patients (81%) had a complete rupture (nine Stener lesions (56%)). One patient had a partial injury and one patient had no UCL-injury. Eight patients (27%) had inconclusive results during physical examination. Of these, two had a complete rupture (40%, 1 Stener). Three patients had a partial rupture and three patients had an intact UCL.

CONCLUSION

A skier's thumb can be diagnosed by any resident when correctly instructed. Additional imaging when diagnosing a skier's thumb should be reserved in cases when physical examination remains inconclusive.

Sonographic diagnosis of an acute Stener lesion: a case report

This case report describes the use of diagnostic ultrasound to diagnose a Stener lesion in a patient who presented for conservative care of thumb pain following a fall on an outstretched hand. Conventional radiographic images demonstrated an avulsion fracture at the ulnar aspect of the base of the first proximal phalanx. Diagnostic ultrasound revealed a torn ulnar collateral ligament of the thumb that was displaced proximal to the adductor aponeurosis, consistent with a Stener lesion. Dynamic imaging with ultrasound confirmed displacement of the fully torn ligament. Surgical repair followed the diagnosis. Diagnostic ultrasound in this case provided an accurate diagnosis obviating further imaging. This allowed an optimal outcome due to early intervention.

Ulnar collateral ligament injuries of the thumb: a comprehensive review

Injuries to the thumb ulnar collateral ligament (UCL) are common. Failure to address the ensuing laxity of the metacarpophalangeal joint can lead to compromised grip and pinch, pain, and ultimately osteoarthritis. Instability to valgus stress with the lack of a firm end point is a strong indicator of complete rupture of the UCL. Nonoperative treatment is reserved for incomplete ruptures of the thumb UCL. Operative intervention is typically performed for complete ruptures. Repair of acute ruptures and reconstruction for chronic injuries yield excellent results. Complications are rare and most patients show preservation of motion, key pinch, and grip strength.

Clinical orthopedic examination findings in the upper extremity: correlation with imaging studies and diagnostic efficacy

Different orthopedic tests are used to evaluate internal derangements of joints. Radiologic examinations like magnetic resonance (MR) imaging are ordered on the basis of results of these tests to narrow the clinical diagnosis and formulate a treatment plan. Although these tests are clinically useful, the test terminology can be confusing and the significance of the tests not clearly understood. This article helps explain the clinical jargon of tests performed for the major joints of the upper extremity and their proper use and diagnostic value in conjunction with MR imaging. The article presents a structured algorithmic approach to explain the tests. For each joint, a hierarchy of clinical tests is performed, starting with general observation and range of motion, followed by more specific tests tailored to evaluate individual or grouped anatomic structures. MR imaging findings and clinical tests complement each other in making a final diagnosis. However, because of the varied sensitivity and specificity of the clinical tests and MR imaging, it is important to be familiar with their diagnostic value before making clinical decisions. Knowledge of clinical jargon and the proper use and diagnostic value of orthopedic tests can aid in interpretation of radiologic images by focusing search patterns, thus allowing comprehensive evaluation and optimized reporting. It also enhances communication with the orthopedist, thereby helping maintain continuity of care. Online supplemental material is available for this article.

The role of US in the evaluation of clinically suspected ulnar collateral ligament injuries of the thumb: spectrum of findings and differential diagnosis

Injury to the ulnar collateral ligament (UCL) complex of the thumb is a common traumatic lesion that requires prompt imaging evaluation for adequate treatment. In this article, we review the role of ultrasound in diagnosis and illustrate the spectrum of both static and dynamic findings related to the UCL injuries. We also describe a number of alternative diagnoses in the vicinity of the first metacarpophalangeal joint that may present clinically as pseudoligamentous lesions in a trauma setting.

[Metacarpophalangeal joint injuries and sequelae]

Injuries of the metacarpophalangeal joints of the thumb and fingers are of a bony or ligamentous nature. They can heal without subsequent problems if correctly diagnosed and treated but incorrect or absent diagnostics and therapy can result in chronic instability, dislocation, fusion as well as subsequent arthritis and functional limitations. They can lead to substantial impairment of the gripping function. Fractures with inclusion of joints and with fragments sufficiently large for refixation are as a rule treated operatively just as differences in torsion and instability. Persisting instabilities are secondarily stabilized by ligamentoplasty and arthritis of the metacarpophalangeal joint of the thumb is treated by fusion. For metacarpophalangeal joints of the fingers the main concern is preserving motion. Established salvage operations for arthritis include denervation, resection arthroplasty and systematic arthrolysis for impairment of the joint and contractures with intact joint surfaces. Even in chronic conditions, with appropriate treatment good functional results for metacarpophalangeal joints of the thumb and fingers can be achieved. This article presents the current pathophysiological principles and concepts for diagnostics and therapy of acute and chronic injuries of the metacarpophalangeal joints of fingers and thumbs.

Management of thumb metacarpophalangeal ulnar collateral ligament injuries

Untreated ulnar collateral ligament (UCL) injury of the thumb metacarpophalangeal joint (MCPJ) can lead to long-term pain and functional limitations.Detection of a UCL injury involves sequential examination of true and accessory ligaments and comparison with the uninjured side.Acute partial UCL injuries can be successfully treated nonoperatively.Acute complete or displaced UCL injuries can be successfully treated with operative repair.In cases of chronic UCL injury, treatment options include static and dynamic reconstructions.If painful arthrosis is present with chronic UCL instability, salvage may be performed with MCPJ fusion.

Thumb metacarpophalangeal joint collateral ligament injury management

The thumb collateral ligaments at the metacarpophalangeal joint are important to the elite athlete for precision grip and pinch. Injuries to these ligaments can result in pain and instability and are seen at a higher frequency at the elite level. Whereas the collateral ligament tears used to be associated primarily with recreational skier's injury, these injuries have been reported with increasing frequency in major professional sports. The ulnar collateral and radial collateral ligament injuries of the thumb occur through different mechanisms and are described in separate sections given the differences in their anatomy.

Magnetic resonance imaging technology in evaluating the presence and integrity of the anterior oblique ligament of the thumb

This investigation examines the reliability and reproducibility of magnetic resonance imaging (MRI) technology in evaluating the anterior oblique ligament (AOL) of the trapeziometacarpal joint (TMC) of the thumb, in order to establish an effective imaging protocol to use in the early identification of conditions leading to degenerative arthritis. We used cadaver specimens, three hand surgeons independently rated from X-rays each specimen. The specimens were then scanned in a General Electric MRI machine with a standard wrist coil. An effort was made to reproduce the image of the AOL - with a unique technique to obtain images of the obliquely oriented thumb and its ligaments. Following the MRI, the specimens were dissected to expose the AOL and visualize the TMC joint. A standard MRI fiducial was sewn to the proximal and distal extent of the volar side of the AOL. The soft tissues were replaced and the skin was closed. They were then rescanned following the same protocol, and pre and post-dissection ligament-labeled specimens were compared. Following dissection and tagging of the AOL ligament, a repeat MRI confirmed its location and validated the protocol in all cases. The open dissection and ligament tagging confirmed that what was visualized was in fact the structure of interest. This investigation demonstrated that with an appropriate MRI protocol it is feasible to guide the scanner to catch appropriate images of a ligament that is closely correlated with degenerative arthritis.

MRI follow-up after free tendon graft reconstruction of the thumb ulnar collateral ligament

OBJECTIVE

Our aim was to analyse whether MRI is useful in the follow-up of reconstruction of the ulnar collateral ligament (UCL) of the metacarpophalangeal joint of the thumb, to describe normal postoperative findings, and to evaluate different MR sequences.

MATERIAL AND METHODS

Our study material consists of 10 patients who, because of a chronic rupture of the ulnar collateral ligament of the thumb, had been operatively treated using a free tendon graft. The patients were, in addition to the clinical examination and radiographs, also imaged using MRI both pre- and postoperatively. The postoperative MRI controls, undertaken at 2, 12 and 24 months were analysed without knowledge of the clinical or radiographic findings.

RESULTS

The reconstructed UCL was well visualised on MRI. One graft rupture was diagnosed on MRI and was later operatively confirmed. No increase in osteoarthritis of the metacarpophalangeal (MP) joint of the thumb was seen during the follow-up. The single most informative MR sequence was T2TSE in the coronal plane.

CONCLUSION

Magnetic resonance imaging may provide a clinically valuable means of assessing graft integrity in patients with suspected postoperative graft failure after UCL reconstruction, although we do not consider MRI necessary in the routine follow-up of patients with an uneventful recovery.

Injury to the ulnar collateral ligament of the thumb

Injury to the ulnar collateral ligament of the thumb is very common and can be disabling when missed or left untreated. We present a review of literature and our preferred way of management.

The role of ultrasound in the evaluation of sports medicine injuries of the upper extremity

The two major imaging modalities used for assessment of soft tissue injuries are ultrasound and MRI. Although ultrasound of the extremities is used only to a limited extent in the United States, it is widely used in many other countries for evaluation of extremity injuries. This article first considers the advantages and disadvantages of MRI and ultrasound. Understanding these differences will help the reader understand the role of ultrasound as compared with MRI in evaluating upper extremity injuries. The uses of ultrasound for evaluating sports medicine injuries in specific regions of the upper extremity are then reviewed. Where the data are available, the reported accuracy of ultrasound is compared with MRI for each type of injury.

MR Imaging of Ligaments and Triangular Fibrocartilage Complex of the Wrist

Imaging of the wrist with MR imaging can be difficult because of the small size of this joint, its complex anatomy, and its sometimes poorly understood pathologic lesions. A recent study by Hobby and coworkers of 98 patients revealed that MR imaging of the wrist influences clinicians' diagnoses and management plans in most patients. This article summarizes the current diagnostic criteria that can be useful in interpreting abnormalities of the wrist ligaments and triangular fibrocartilage complex (TFCC) of the wrist in this difficult topic in joint MR imaging.

High- Versus Low-Field MR Imaging

The role of MR imaging as a noninvasive technique in the detection and evaluation of musculoskeletal diseases is unquestionable. Most of the studies reported in the literature are based on high-field MR imaging. Initial studies performed with low-field-strength have reported unsatisfactory results in the assessment of the musculoskeletal system. Recent improvements, however, have generated a renewed interest in low-field-strength MR imaging. This article presents the principal applications and results published in the literature.

MR imaging of the metacarpophalangeal joints of the fingers: evaluation of 38 patients with chronic joint disability

OBJECTIVE

To report the MR imaging findings of painful injured metacarpophalangeal (MCP) joints of the fingers.

DESIGN AND PATIENTS

MR imaging of 39 injured MCP joints in 38 patients was performed after a mean delay of 8.8 months. The MR images were obtained with the fingers in extended and flexed positions using T2-weighted and T1-weighted sequences before and after intravenous injection of a gadolinium compound. Ten patients were treated surgically. Mean clinical follow-up was 1.8 years.

RESULTS

Tears of the collateral ligaments were the most common lesion (30/39), most being radial in location. Contrast-enhanced axial T1-weighted images with the MCP joint in a flexed position showed these lesions optimally. Ten tears were partial and 20 were complete. In 13 patients, MR images showed 17 associated lesions including injuries of the extensor hood (10/17), interosseous tendon (3/17), palmar plate (3/17), and an osteochondral lesion (1/17). Sagittal MR images were essential to highlight palmar plate tears.

CONCLUSION

Partial or complete tears of the collateral ligaments are prevalent MR imaging findings in patients with chronic disability resulting from injuries to the MCP joints. Although conservative treatment generally is sufficient for isolated injuries of the collateral ligaments, surgical repair is often required in cases of more extensive injuries. MR imaging may clearly delineate associated lesions of and about the MCP joints.

Musculoskeletal colloquialisms: how did we come up with these names?

Eponyms and colloquial terms are labels that provide two kinds of information: the pattern of a complex injury or pathologic problem and, in the case of an eponym, the name of an individual who has been closely identified with the pathologic problem. Such terms remind us that the medicine of today is not entirely the work of our contemporaries. The article illustrates many of the common colloquial terms applied to fractures and musculoskeletal injuries seen in everyday practice. Wherever possible, the illustrations and definitions are based on the original descriptions of the injuries.

MR imaging of ligaments and triangular fibrocartilage complex of the wrist

Imaging of the wrist with MR imaging can be difficult because of the small size of this joint, its complex anatomy, and its sometimes poorly understood pathologic lesions. A recent study by Hobby and coworkers of 98 patients revealed that MR imaging of the wrist influences clinicians' diagnoses and management plans in most patients. This article summarizes the current diagnostic criteria that can be useful in interpreting abnormalities of the wrist ligaments and triangular fibrocartilage complex (TFCC) of the wrist in this difficult topic in joint MR imaging.

In-office MR imaging

The development of new metal alloys, along with more innovative magnet technology, has permitted the construction of smaller magnets for magnetic resonance (MR) systems, which, in turn, has allowed development of MR imaging systems designed to be physically smaller than conventional whole-body MR imaging systems. These specialized devices are commonly referred to as "niche," "dedicated," or "extremity" MR imaging systems. Performing MR imaging procedures with this type of system offers distinct advantages that include reduced overall costs, more convenient installation and siting, and greater patient comfort and safety. Importantly, these critical features permit extremity MR imaging systems to be readily utilized in an "in-office" setting. This article will provide an overview of the technical aspects and clinical applications for extremity MR imaging systems, present patient management issues, and discuss the economic and practical considerations of the use of extremity MR imaging systems in an in-office environment.

MR imaging of ligament and tendon injuries of the fingers

Magnetic resonance (MR) imaging can provide important information for diagnosis and evaluation of soft-tissue trauma in the fingers. An optimal imaging technique should include proper positioning, dedicated surface coils, and specific protocols for the suspected abnormalities. Familiarity with the fine anatomy of the normal finger is crucial for identifying pathologic entities. MR imaging is a powerful method for evaluating acute and chronic lesions of the stabilizing articular elements (volar plate and collateral ligaments) of the fingers and thumbs, particularly in the frequently affected proximal interphalangeal and metacarpophalangeal joints. As in other body regions, MR imaging is also useful for depicting traumatic conditions of the extensor and flexor tendons, including injuries to the pulley system. In general, normal ligaments and tendons have low signal intensity on MR images, whereas disruption manifests as increased signal intensity. Radiologists need to understand the full spectrum of finger abnormalities and associated MR imaging findings.

MR imaging of the metacarpophalangeal joints of the fingers: part II. Detection of simulated injuries in cadavers

PURPOSE

To evaluate and compare conventional magnetic resonance (MR) imaging and MR arthrography in the diagnosis of the most common traumatic metacarpophalangeal (MCP) joint injuries, which were created surgically in cadavers.

MATERIALS AND METHODS

Injuries to various MCP joint structures were surgically created randomly in 28 fingers of seven human cadaveric hands. Injuries to the main collateral ligaments (CLs) (n = 12), accessory CL (n = 15), sagittal band (n = 14), transverse fibers of the extensor hood (n = 5), first annular pulley (n = 16), deep transverse metacarpal ligament (DTML) (n = 5), and palmar plate (n = 10) were analyzed. Conventional MR images and MR arthrograms were evaluated, with differences in interpretation resolved in consensus. The sensitivities, specificities, and accuracies of both MR imaging methods were determined, and the differences were tested for significance by using the McNemar test.

RESULTS

Sensitivity was 28.6%-93.8% with conventional MR imaging versus 50.0%-93.3% with MR arthrography. Specificity was 66.7%-100% with conventional MR imaging versus 83.3%-100% with MR arthrography. Although the MR arthrographic results usually were higher, the differences were not significant. The kappa values for interobserver agreement were 0.314-0.638 for conventional MR imaging versus 0.364-1.00 for MR arthrography. Sensitivity for the detection of lesions of the main and accessory CLs and the first annular pulley was slightly higher than that for the detection of lesions of the extensor hood, DTML, and palmar plate structures.

CONCLUSION

MR imaging and MR arthrography enable the diagnosis of simulated MCP joint injuries. MR arthrography does not have a significant advantage over conventional MR imaging.

MR imaging of the metacarpophalangeal joints of the fingers: part I. Conventional MR imaging and MR arthrographic findings in cadavers

PURPOSE

To demonstrate the normal anatomy of the metacarpophalangeal (MCP) joints of the fingers with magnetic resonance (MR) imaging and MR arthrography in cadavers.

MATERIALS AND METHODS

MR images of 20 MCP joints of the fingers of five fresh human cadaveric hands in the extended and flexed positions were obtained before and after arthrography. The MR appearances of all articular and periarticular structures were analyzed and compared with those seen on anatomic sections. Two readers independently graded the visibility of these structures. Interobserver agreement was tested by using the kappa statistic.

RESULTS

The main collateral ligaments could be best evaluated on the transverse images of flexed fingers. The accessory bands of the collateral ligament complex were best seen on the transverse images of extended fingers. Sagittal MR images were best for evaluating the palmar plate and the capsule. MR arthrography improved the visualization of all articular and periarticular structures. The kappa values related to conventional MR imaging findings at all sequences, 0.42-0.71, indicated moderate to substantial agreement. The kappa values for the MR arthrographic sequences, 0.59-0.74, were slightly higher than those for the nonenhanced sequences.

CONCLUSION

Conventional MR imaging and MR arthrography enable accurate visualization of the important anatomic structures of the MCP joints. MR arthrography enhances visualization of the intraarticular elements.

Evaluation of the rotator cuff and glenoid labrum using a 0.2-Tesla extremity magnetic resonance (MR) system: MR results compared to surgical findings

The purpose of this investigation was to evaluate the diagnostic capabilities of magnetic resonance imaging (MRI) performed using a dedicated-extremity MR system in detecting lesions of the rotator cuff and glenoid labrum. This retrospective study compared the MR results obtained in 47 patients that underwent MRI using a 0.2-Tesla extremity MR system (E-scan) to the surgical findings. MR images of the shoulder were obtained as follows: shoulder coil, T1-weighted, coronal-oblique and axial images; short Tau inversion recovery (STIR), coronal-oblique images; and T2-weighted, coronal-oblique, sagittal-oblique, and axial images. The MR examinations were interpreted by three highly experienced, musculoskeletal radiologists. Open surgical (N = 26) or arthroscopic (N = 21) procedures were performed within a mean time of 33 days after MRI. The surgical findings revealed rotator cuff tears in 28 patients and labral lesions in 9 patients. For the rotator cuff tears, the sensitivity, specificity, positive predictive value, and negative predictive value were 89%, 100%, 100%, and 90%, respectively. For the labral lesions, the sensitivity, specificity, positive predictive value, and negative predictive value were 89%, 95%, 80%, and 97%, respectively. The findings indicated that there was good agreement comparing the MR results obtained using the low-field extremity MR system to the surgical findings for determination of lesions of the rotator cuff and glenoid labrum. Notably, the statistical values determined for the use of this MR system were comparable to those reported in the peer-reviewed literature for the use of whole-body, mid- and high-field-strength MR systems.

Temporal behavior of intraarticular gadolinium

PURPOSE

As imaging delays during MR arthrography can result in suboptimal studies and potential pitfalls in diagnosis, we sought to evaluate the temporal behavior of intraarticular Gd-DTPA.

METHOD

We prospectively studied four shoulders, four knees, and four hips. Two of each group received either an intraarticular injection of 3 mmol/L Gd-DTPA and iodinated contrast medium or 2 mmol/L Gd-DTPA and 0.9% saline. We measured contrast-to-noise ratio (CNR) and joint distention on serial T1-weighted sequences. Retrospectively, we measured CNR and imaging delays in 31 MR arthrography patients (20 shoulders, 7 knees, and 4 hips).

RESULTS

In the shoulder, maximal CNR and joint distention occurred at 15 min. CNR decreased 53% by 1 h. In the knee, maximal distention occurred at 1 h, whereas CNR peaked at 2.75 h and then declined 20 and 86% by 3.5 and 6.25 h, respectively. In the hip, peak CNR and distention occurred at 0.5 h. CNR declined 53% by 2 h. Both contrast mixtures yielded similar results.

CONCLUSION

MR arthrography may tolerate imaging delays of 1 h for the shoulder, 2 h for the hip, and 3.5 h for the knee.

Magnetic resonance arthrography: current status

Magnetic resonance imaging (MRI) is frequently considered the best method of diagnosis in musculoskeletal disorders. Intraarticular fluid improves joint assessment by helping to delineate intraarticular structures, separating otherwise closely-apposed structures, and filling potential spaces which lie within or communicate with the joint. Initially, it was anticipated that plain MRI would replace arthrography. The message from our surgical colleagues is that this ideal has not yet been achieved. Greater precision should reduce the need for more invasive techniques, such as diagnostic arthroscopy which is why direct and indirect MR arthrography are being employed. This article reviews the current status of MR arthrography as an evolving technique in the imaging of joint disorders.