Magnetic resonance imaging of the elbow: a structured approach

Traction MRI of the Elbow: Age-Based Effects and Implications

BACKGROUND/OBJECTIVES

We previously reported that traction magnetic resonance imaging (MRI) of the elbow without arthrography increases the width of the radiocapitellar joint (RC) and improves articular cartilage visibility. However, the effects of axial traction on different age groups have not yet been evaluated. We hypothesized that the effect of traction would decrease as the participants' age increased.

METHODS

We enrolled 30 healthy volunteers, ten each in their 20s, 30s, and 40s. The male-to-female ratio in each age group was 1:1. Elbow MRI was performed without traction and with 3, 5, and 7 kg axial traction. We evaluated joint space width (JW), humeral articular cartilage visibility, and intraprocedural pain/discomfort. We measured JW and cartilage visibility at the RC and the lateral and medial thirds of the ulnohumeral joint.

RESULTS

The older age groups exhibited narrower JWs without traction. Axial traction increased the JW and improved the visibility of the RC in all age groups. No significant differences were observed in the ulnohumeral joint's lateral or medial thirds, but pain and discomfort increased with heavier traction weights.

CONCLUSIONS

For participants in their 20s and 30s, axial traction of 3 kg seemed appropriate, while 7 kg traction was considered for those in their 40s.

Management of Pediatric Elbow Fractures and Dislocations

Pediatric elbow fractures and dislocations have always been a challenge from a diagnostic and therapeutic point of view, primarily due to the complex nature of the pediatric elbow, especially its developmental anatomy. They must be diagnosed and treated on time to prevent numerous complications with long-term consequences. With the development of radiology and pediatric surgery and orthopedics, as well as the development of modern osteosynthesis materials, concerning current scientific and professional knowledge, the outcomes are getting better, with fewer acute and chronic complications. This comprehensive review aims to provide clinicians current knowledge about pediatric elbow fractures and dislocations so that in daily practice they have as few doubts as possible with the best possible treatment outcomes.

Current concepts of natural course and in management of medial epicondylitis: a clinical overview

Medial epicondylitis (ME), called "golfer's elbow", is not frequent or serious disease but can cause symptoms that are bothersome in everyday life. Therefore knowledge about this condition may improve diagnostic-therapeutic process. In this article detailed information concerning pathophysiology and symptomatology of ME was described. Great attention was paid to issues related to the diagnosis of the disease both in terms of differentiation with other elbow disorders as well as examination techniques. Finally, current therapeutic options were presented in detail and their efficacy was discussed based on the available data.

Sites of flexor-pronator muscle injury and relationship between ulnar collateral ligament injury and flexor-pronator muscle injury in baseball players: a retrospective cohort study

BACKGROUND

Ulnar collateral ligament (UCL) and flexor-pronator muscle (FPM) injuries are common in baseball players. However, the sites of FPM injuries and the relationship between UCL and FPM injuries in baseball players have not been fully clarified. The purpose of this study was to identify the sites of FPM injuries and to determine the relationships of location and severity of UCL injury with the presence of FPM injuries in baseball players.

METHODS

UCL and FPM injuries were diagnosed using magnetic resonance imaging in 99 baseball players. The sites of FPM injuries were identified on coronal, sagittal, and axial images. UCL injury severity was classified into four grades: chronic changes, low-grade partial tear, high-grade partial tear, and complete tear. UCL injury location was classified as proximal UCL tear or distal UCL tear. All images were assessed by a musculoskeletal radiologist and an orthopedic surgeon.

RESULTS

Combined UCL and FPM injuries were observed in 45 of 99 players, of which 40 of 45 (89%) involved injury of the flexor digitorum superficialis (FDS). All FDS injuries were in the deep layer of the muscle belly. There was no significant difference between the severity of UCL injury and presence of FPM injuries (P = .352). There was a significant association of distal UCL tears with FPM injuries (P < .001).

CONCLUSION

FDS injury occurs most commonly in the muscle belly of the second and fifth digits. There may be no relationship between the severity of UCL injury and presence of FPM injury in baseball players. FPM injuries may be a contributing factor in the failure of nonoperative management of distal UCL tears in baseball players.

Mechatronic Design of a Prototype Orthosis to Support Elbow Joint Rehabilitation

Injuries in the elbow area, such as lateral and medial epicondylitis, are the leading causes of consultation with health specialists. Therefore, this research proposes the mechatronic design of an orthosis with a graphic interface that supports professionals in the rehabilitation of the elbow joint through the execution of flexion–extension and pronation–supination movements. For the development of the rehabilitation prototype, mechatronic design, co-design, and IDEF0 methodologies are used, performing activities such as actuator characterization, simulations, and modeling, among others. Through the execution of a case study in a real environment, the device was validated, where the results suggest a functional and workable prototype that supports the treatment of pathologies in the elbow area through the execution of the mentioned movements, supposing that this is a low-cost alternative with elements to improve, such as the industrial design and new functionalities. The developed proposal shows potential as an economical product that health professionals can use. However, some limitations related to the design and functionalities in the application domain were identified.

Preoperative Evaluation and Surgical Simulation for Osteochondritis Dissecans of the Elbow Using Three-Dimensional MRI-CT Image Fusion Images

We used our novel three-dimensional magnetic resonance imaging-computed tomography fusion images (3D MRI-CT fusion images; MCFIs) for detailed preoperative lesion evaluation and surgical simulation in osteochondritis dissecans (OCD) of the elbow. Herein, we introduce our procedure and report the findings of the assessment of its utility. We enrolled 16 men (mean age: 14.0 years) and performed preoperative MRI using 7 kg axial traction with a 3-Tesla imager and CT. Three-dimensional-MRI models of the humerus and articular cartilage and a 3D-CT model of the humerus were constructed. We created MCFIs using both models. We validated the findings obtained from the MCFIs and intraoperative findings using the following items: articular cartilage fissures and defects, articular surface deformities, vertical and horizontal lesion diameters, the International Cartilage Repair Society (ICRS) classification, and surgical procedures. The MCFIs accurately reproduced the lesions and correctly matched the ICRS classification in 93.5% of cases. Surgery was performed as simulated in all cases. Preoperatively measured lesion diameters exhibited no significant differences compared to the intraoperative measurements. MCFIs were useful in the evaluation of OCD lesions and detailed preoperative surgical simulation through accurate reproduction of 3D structural details of the lesions.

Magnetic resonance imaging evaluation of patients with clinically diagnosed medial Epicondylitis

OBJECTIVE

We evaluated magnetic resonance imaging (MRI) findings in patients with clinically diagnosed medial epicondylitis (ME) and determined whether any of the MRI findings correlated with the follow-up pain level after nonoperative treatment.

MATERIALS AND METHODS

We retrospectively reviewed 83 patients who had undergone elbow MRI examinations for clinically diagnosed ME and who were followed-up for more than 6 months. Five categories of MRI findings were selected for qualitative grading: common flexor tendon (CFT) origin signal changes, ulnar collateral ligament (UCL) insufficiency, ulnar neuritis, bony changes of the medial epicondyle, and calcification. The mean follow-up after MRI examination was 21 months. We performed multivariate regression analysis to analyze whether any of these MRI findings were associated with the follow-up pain level after nonoperative treatment.

RESULTS

Positive MRI findings included CFT origin signal changes (66%), ulnar neuritis (40%), UCL insufficiency (30%), calcification (27%), and bony changes (18%). Multivariate analysis indicated that CFT origin signal changes were independently associated with the follow-up pain level (β = 3.387; p = 0.004).

CONCLUSION

In patients with clinically diagnosed ME, MRI demonstrated diverse abnormal findings in the CFT origin, ulnar collateral ligament, ulnar nerve, and bone. Among the findings, the severity CFT origin signal changes, which indicates the severity of tendon degeneration in ME, was associated with the follow-up pain level. This information can be helpful in consulting on the prognosis of nonoperative treatment in patients with clinically diagnosed ME.

Evaluation of the association between olecranon fracture and radial head subluxation or annular ligament displacement in children

Olecranon fractures are seen substantially more often in children than in adult and are potentially occult in nature. We noticed this fracture pattern in two cases of delayed Monteggia fracture. Our study purpose was to confirm whether olecranon fracture is associated with radial head subluxation or annular ligamentous displacement in children. In addition, we have developed an effective and simple approach to avoid serious treatment-related complications as much as possible. Forty-eight pediatric patients with olecranon fracture and normal radiocapitellar alignment on radiography were enrolled. All patients' fingers, forearms and elbows were examined carefully, and treated with a modified radial head reduction approach and then cast immobilization. MRI of the affected elbow was performed in 16 symptomatic patients. Overall, 70.83% of patients had a positive clinical finding of radial head subluxation. These symptomatic patients presented with similar clinical findings that typically included painful finger movement actively or passively and movement limitation of forearm and elbow. MRI showed that annular ligaments were interposed and trapped in the radiohumeral joint. In 34 symptomatic patients, 91.18% of them achieved fair radial head reduction during the first reduction attempt. Herein, 95.85 and 100% of patients reported excellent and satisfactory outcomes, respectively. Radial head subluxation occurred in most children with an olecranon fracture. We highly suggest performing a careful physical examination to identify this fracture pattern. Early reduction of the radial head with the modified approach may be a simple and primary option for emergency room doctors.

Use of Magnetic Resonance Imaging for Orthopedic Trauma and Infection in the Emergency Department

Conditions affecting the musculoskeletal system constitute a significant portion of medical emergencies in the United States, with traumatic injury and infection being two of the most common etiologies. Although physical examination and plain radiographs are often sufficient to guide diagnosis and treatment, there are myriad traumatic and infectious pathologies that are commonly missed or simply not detectable on plain radiographs. Advanced imaging is subsequently warranted for additional workup.Magnetic resonance imaging (MRI) has become an increasingly used imaging modality for musculoskeletal complaints in the emergency department due to its superior visualization of soft tissues, focal edematous changes, and occult osseous insults often not visible on plain radiographs. Although multiple studies have evaluated its utility in the workup of emergency musculoskeletal complaints, there remains a dearth of literature examining the use of MRI for certain occult diagnoses.Radiologists, emergency clinicians, and orthopedic surgeons must be knowledgeable of the indications for MRI in the emergency setting, as delayed diagnosis may contribute to increased morbidity and possibly mortality. This review summarizes the use of MRI in diagnoses relating to trauma or infection among patients presenting to the emergency department with a musculoskeletal complaint.

Clinical, Radiological, and Electrodiagnostic Diagnosis of Pronator Syndrome Concurrent With Carpal Tunnel Syndrome

PURPOSE

This is a retrospective observational study that assessed the prevalence of positive diagnostic imaging and electrodiagnostic (EDX) findings in patients diagnosed with pronator syndrome (PS), who previously had a carpal tunnel syndrome (CTS) surgery. The other purpose of our study was to determine how often PS occurred and was missed in patients treated surgically for CTS.

METHODS

The files of 180 patients who underwent CTS surgery were reviewed retrospectively. We assessed all patients for a diagnosis of PS. We accepted the clinical findings and patient history as the reference standard for the diagnosis of PS. Anteroposterior and lateral radiographs of the elbow, bilateral upper limb magnetic resonance imaging (MRI) studies, and bilateral dynamic forearm ultrasound (US) were performed on patients with clinical symptoms and physical examinations that indicated PS. Bilateral upper limb EDX was also performed for these patients. One patient refused additional tests.

RESULTS

A total of 174 extremities in 146 patients were included in the study. Pronator syndrome was diagnosed by 2 hand surgeons in 22 extremities (19 patients) through a clinical evaluation that included a history and physical examination. Diagnostic testing was positive for findings of PS in 24% of extremities (5 of 21) tested by EDX, in 57% of extremities (12 of 21) tested by US, and 5% of extremities (1 of 21) tested by MRI. There was no lower humeral spur that could cause median nerve compression on any plain radiographs.

CONCLUSIONS

With clinical evaluation as the reference standard, EDX, US, and MRI are not helpful in making a diagnosis of PS concurrent with CTS.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

Effect of elbow MRI with axial traction on articular cartilage visibility-a feasibility study

OBJECTIVE

Accurate evaluation of the articular cartilage of the elbow using MRI is sometimes challenging because of its anatomical complexity and relatively small size. Moreover, the articular cartilage of the humerus is in close contact with the opposing cartilage surfaces. Magnetic resonance arthrography with traction was reported to resolve this issue; however, less invasive methods are desirable. This study aimed to assess the effect of MRI with axial traction (without arthrography) on joint space widening and cartilage outline visibility of the elbow.

MATERIALS AND METHODS

We enrolled 10 volunteers (female = 1; mean age, 36.7 ± 8.6; range 28-56) and performed MRI with and without axial traction on the elbow. Joint space widths were measured, and the humeral articular cartilage outline visibility was evaluated at the radiocapitellar joint and lateral one-third and medial one-third of the ulnohumeral joints. Measurements were compared using the Wilcoxon signed-rank test. Significance was set at p < 0.05. Volunteers scored pain and discomfort during MRI with traction using the visual analog scale in a questionnaire format.

RESULTS

Traction significantly increased joint space width at the radiocapitellar joint. Humeral articular cartilage outline visibility also significantly improved at the radiocapitellar joint. Pain and discomfort scores during traction MRI were low.

CONCLUSION

MRI of the elbow with traction widens joint space and enables better articular cartilage visibility at the radiocapitellar joint. Anatomical features of the elbow might have affected these results. Therefore, it would be safe and useful for evaluating elbow injuries involving articular cartilage lesions.

Magnetic resonance imaging of the elbow

Elbow pain can cause disability, especially in athletes, and is a common clinical complaint for both the general practitioner and the orthopaedic surgeon. Magnetic resonance imaging (MRI) is an excellent tool for the evaluation of joint pathology due to its high sensitivity as a result of high contrast resolution for soft tissues. This article aims to describe the normal imaging anatomy and biomechanics of the elbow, the most commonly used MRI protocols and techniques, and common MRI findings related to tendinopathy, ligamentous and osteochondral injuries, and instability of the elbow.

Triceps Tendon Ruptures: Risk Factors, Treatment, and Rehabilitation

Triceps tendon ruptures (TTRs) are rare and often occur as a result of falling on an outstretched hand, forceful eccentric contraction, direct trauma to the elbow, or lifting against resistance. TTRs are most commonly seen in middle-aged men, football players, and weightlifters. Radiography, ultrasonography, and magnetic resonance imaging may be utilized for diagnosis and to guide treatment. Acute partial TTRs may have good outcomes with nonoperative management. Surgery should be considered if nonoperative treatment is unsuccessful or if substantial musculotendinous retraction is present. Surgical repair is strongly recommended for complete TTRs.

Anatomic Study of the Elbow Joint in a Bengal Tiger (Panthera tigris tigris) Using Magnetic Resonance Imaging and Gross Dissections

The objective of our research was to describe the normal appearance of the bony and soft tissue structures of the elbow joint in a cadaver of a male mature Bengal tiger (Panthera tigris tigris) scanned via MRI. Using a 0.2 Tesla magnet, Spin-echo (SE) T1-weighting, and Gradient-echo short tau inversion recovery (GE-STIR), T2-weighting pulse sequences were selected to generate sagittal, transverse, and dorsal planes. In addition, gross dissections of the forelimb and its elbow joint were made. On anatomic dissections, all bony, articular, and muscular structures could be identified. The MRI images allowed us to observe the bony and many soft tissues of the tiger elbow joint. The SE T1-weighted MR images provided good anatomic detail of this joint, whereas the GE-STIR T2-weighted MR pulse sequence was best for synovial cavities. Detailed information is provided that may be used as initial anatomic reference for interpretation of MR images of the Bengal tiger (Panthera tigris tigris) elbow joint and in the diagnosis of disorders of this region.

Magnetic resonance imaging of elbow injuries in children

Evaluating elbow injuries is challenging because of the complex anatomy of the joint. In children, injury patterns depend on the sports-specific mechanism as well as the stage of skeletal maturity. This article reviews the anatomy of the elbow and common injury patterns seen in children, with an emphasis on MRI and the throwing athlete. Imaging pitfalls specific to children are described.

Analysis of magnetic resonance imaging-confirmed soft tissue injury pattern in simple elbow dislocations

BACKGROUND

The elbow is the second most commonly dislocated joint. Stability depends on the degree of soft tissue injury, with 2 proposed patterns, one starting laterally and the other medially. The purpose of this study was to describe the injured structures observed in magnetic resonance images (MRIs) in a prospective cohort of simple elbow dislocations.

METHODS

We evaluated 17 consecutive cases of simple elbow dislocations. Two musculoskeletal radiologists assessed the initial x-ray images and MRIs performed for all elbows. Radiologists evaluated the following soft tissue structures: medial collateral ligament complex (MCL), flexor-pronator muscle mass origin, anterior capsule (AC), posterior capsule, lateral collateral ligament complex (LCL), and extensor muscle mass origin. The radiologists were blinded to the study hypothesis.

RESULTS

The initial radiographs in 16 patients showed the dislocation was posterolateral in 12, posterior in 3, and posteromedial in 1. We observed complete AC tear in 12 patients, MCL in 10, and LCL in 9. The inter-rater reliability for the radiologists was 0.70 (substantial) for MRI.

CONCLUSIONS

In our series after simple elbow dislocation, complete AC tears were most common, followed by MCL and LCL tears. No single mechanism-related soft tissue injury pattern of simple elbow dislocation was observed, and different grades of soft tissue injury exist.

Forearm Flexor Injuries Among Major League Baseball Players: Epidemiology, Performance, and Associated Injuries

BACKGROUND

Despite evidence highlighting the importance of the forearm flexor muscles of elite baseball players, no studies have reported on the epidemiology of flexor strains and their associated outcomes.

PURPOSE

To examine the incidence, associated injuries, and outcomes associated with forearm flexor injuries among major and minor league baseball players.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Injury data attributed to forearm flexor injuries among Major League Baseball (MLB) and minor league teams between 2010 and 2014 were obtained from the professional baseball Health and Injury Tracking System. This analysis included the number of players injured, seasonal timing of injury, days spent on the disabled list (DL), preinjury performance data, and subsequent injuries.

RESULTS

A total of 134 and 629 forearm flexor injuries occurred in MLB and the minor leagues, respectively. The mean player age was 28.6 and 22.8 years in the MLB and minor leagues, respectively. The mean time spent on the DL for MLB players was 117.0 days, as opposed to 93.9 days in the minor leagues ( P = .272). Interestingly, pitcher performance declined in all categories examined leading up to the season of injury, with significant differences in walks plus hits per inning pitched ( P = .04) and strike percentage ( P = .036). Of MLB players with a forearm injury, subsequent injuries included 50 (37.3%) shoulder, 48 (35.8%) elbow, and 24 (17.9%) forearm injuries. Among injured minor league players, subsequent injuries included 170 (27.0%) shoulder, 156 (24.8%) elbow, and 83 (13.2%) forearm injuries. These rates of subsequent injuries were significantly higher compared with the rates of injuries sustained among players without forearm injuries in both leagues ( P < .001). Finally, 26 (19.4%) MLB and 56 (8.9%) minor league players required an ulnar collateral ligament reconstruction, rates that were significantly higher compared with players without a flexor strain ( P < .001).

CONCLUSION

Flexor-pronator injuries are responsible for considerable time spent on the DL for elite players in MLB and the minor leagues. The most significant findings of this investigation illustrate that a flexor strain may be a significant risk factor for subsequent upper extremity injuries, including an ulnar collateral ligament tear.

Magnetic Resonance Imaging Predictors of Failure in the Nonoperative Management of Ulnar Collateral Ligament Injuries in Professional Baseball Pitchers

BACKGROUND

A medial ulnar collateral ligament (UCL) injury of the elbow is an increasingly common injury in professional baseball pitchers. Predictors of success and failure are not well defined for the nonoperative management of these injuries.

PURPOSE

To evaluate the efficacy of objective measures to predict failure of the nonoperative management of UCL injuries.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Thirty-two professional pitchers (82%) met inclusion criteria and underwent an initial trial of nonoperative treatment for UCL tears based on clinical and radiological findings. Age, preseason physical examination results, magnetic resonance imaging (MRI) characteristics, and performance metrics were analyzed for these pitchers. Successful nonoperative management was defined as a return to the same level of play or higher for >1 year. Failure was defined as recurrent pain or weakness requiring a surgical intervention after a minimum of 3 months' rest when attempting a return to a throwing rehabilitation program.

RESULTS

Thirty-two pitchers (mean age, 22.3 years) who underwent initial nonoperative treatment of UCL injuries were evaluated. Thirty-four percent (11/32) failed and required subsequent ligament reconstruction. Sixty-six percent (21/32) successfully returned to the same level of play for 1 year without a surgical intervention. There was no significant difference seen in physical examination findings or performance metrics between these patients. When comparing MRI findings between the groups, 82% (9/11) ( P < .001) who failed nonoperative management had distal tears, and 81% (17/21) who did not fail had proximal tears ( P < .001). When adjusting for age, location, and evidence of chronic changes on MRI, the likelihood of failing nonoperative management was 12.40 times greater ( P = .020) with a distal tear. No other variable alone or in combination reached significance. When combining the parameters of a high-grade tear and distal location, 88% (7/8) failed nonoperative management.

CONCLUSION

In professional pitchers, distal UCL tears showed significantly higher odds of failure with nonoperative management compared with proximal tears. Thus, tear location should be considered when deciding between operative and nonoperative management.

Ultra-high field upper extremity peripheral nerve and non-contrast enhanced vascular imaging

OBJECTIVE

The purpose of this study was to explore the efficacy of Ultra-high field [UHF] 7 Tesla [T] MRI as compared to 3T MRI in non-contrast enhanced [nCE] imaging of structural anatomy in the elbow, forearm, and hand [upper extremity].

MATERIALS AND METHOD

A wide range of sequences including T1 weighted [T1] volumetric interpolate breath-hold exam [VIBE], T2 weighted [T2] double-echo steady state [DESS], susceptibility weighted imaging [SWI], time-of-flight [TOF], diffusion tensor imaging [DTI], and diffusion spectrum imaging [DSI] were optimized and incorporated with a radiofrequency [RF] coil system composed of a transverse electromagnetic [TEM] transmit coil combined with an 8-channel receive-only array for 7T upper extremity [UE] imaging. In addition, Siemens optimized protocol/sequences were used on a 3T scanner and the resulting images from T1 VIBE and T2 DESS were compared to that obtained at 7T qualitatively and quantitatively [SWI was only qualitatively compared]. DSI studio was utilized to identify nerves based on analysis of diffusion weighted derived fractional anisotropy images. Images of forearm vasculature were extracted using a paint grow manual segmentation method based on MIPAV [Medical Image Processing, Analysis, and Visualization].

RESULTS

High resolution and high quality signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]-images of the hand, forearm, and elbow were acquired with nearly homogeneous 7T excitation. Measured [performed on the T1 VIBE and T2 DESS sequences] SNR and CNR values were almost doubled at 7T vs. 3T. Cartilage, synovial fluid and tendon structures could be seen with higher clarity in the 7T T1 and T2 weighted images. SWI allowed high resolution and better quality imaging of large and medium sized arteries and veins, capillary networks and arteriovenous anastomoses at 7T when compared to 3T. 7T diffusion weighted sequence [not performed at 3T] demonstrates that the forearm nerves are clearly delineated by fiber tractography. The proper digital palmar arteries and superficial palmar arch could also be clearly visualized using TOF nCE 7T MRI.

CONCLUSION

Ultra-high resolution neurovascular imaging in upper extremities is possible at 7T without use of renal toxic intravenous contrast. 7T MRI can provide superior peripheral nerve [based on fiber anisotropy and diffusion coefficient parameters derived from diffusion tensor/spectrum imaging] and vascular [nCE MRA and vessel segmentation] imaging.

Interobserver and intraobserver agreement of ligamentous injuries on conventional MRI after simple elbow dislocation

Background

The primary objective of this study was to assess the interobserver and intraobserver agreement on ligamentous injuries on conventional magnetic resonance imaging (MRI) in acute simple elbow dislocation. The secondary objectives were to determine the interobserver agreement on the assessment of joint congruity, joint effusion, loose bodies and chondral lesions on conventional MRI.

Methods

Conventional MRIs (1.5 Tesla, elbow specific surface coil) of 30 patients (40.7 years; range 14–72) with simple elbow dislocations were evaluated by four blinded examiners. An analysis of the interobserver agreement of all raters and for several subgroups (radiologists, orthopaedics, experienced, non-experienced) was performed. The examiners assessed the integrity (intact, partial tear, complete tear) of the lateral collateral ligament (LCL), medial collateral ligament (MCL), extensor and flexor tendons, as well as the presence of joint congruity, joint effusion, loose bodies and chondral lesions. Agreement strength, correlation and proportion of exact agreement were determined for interobserver agreement, and intraobserver agreement analyses.

Results

Interobserver agreement of all examiners was fair to moderate for collateral ligaments (LCL: 0.441, MCL: 0.275). Exact agreement of all raters was found in 33.3% for the LCL and in 26.7% for the MCL. The both experienced examiners showed highest agreement strength for the LCL (0.619) and the radiologists showed highest agreement strength for the MCL (0.627), the proportion of exact agreement was 60.0% in both categories. A high proportion of exact agreement regarding joint congruity (90%), joint effusion (100%), loose bodies (96.7%) and chondral lesion (80%) was found among the radiologists. The evaluation of the intraobserver agreement revealed slight to substantial agreement (0.227 to 0.718) for the collateral ligaments.

Conclusions

This study shows difficulties in the evaluation of ligaments by conventional MRI technique as demonstrated by a weak inter- and intraobserver agreement. This should be the basis to develop new MRI quality standards with special focus on coronal oblique reconstructions to improve the evaluation of ligament injuries after simple elbow dislocations.

Elbow MR arthrography with traction

OBJECTIVE

To assess the effect of axial traction during MR arthrography (MRA) of the elbow joint on joint space widening, contrast dispersion between opposing cartilage surfaces and cartilage surface visibility.

METHODS

11 patients with elbow MRA with and without axial traction were prospectively studied. Two radiologists independently measured the elbow joint space width and semi-quantitatively graded contrast material dispersion between the opposing cartilage surfaces as well as the articular cartilage surface visibility before and after traction. The detection and visibility of articular cartilage defects were also compared before and after traction. Patients were instructed to report on pain or any other symptoms during elbow traction.

RESULTS

No patient reported discomfort, pain or any other symptoms related to traction on immediate and intermediate-term follow-up. Joint space width increased, more at the radiocapitellar joint space (Δ = 0.63 mm, p = 0.005) than at the ulnotrochlear joint space (Δ = 0.17 mm, p = 0.012), with contrast dispersion into the radiocapitellar joint and cartilage visibility of the radiocapitellar joint space significantly improving after traction (all p < 0.05). All of these parameters also improved at the ulnotrochlear joint, although this did not reach statistical significance. Traction improved the visibility of cartilage defects.

CONCLUSION

This is the first study to evaluate the effect of traction on MRA of the elbow joint. This technique is safe and technically feasible. Traction MRA improves the cartilage surface visibility and cartilage defect visibility.

ADVANCES IN KNOWLEDGE

This technique is safe and technically feasible. Traction MRA improves cartilage surface visibility and cartilage defect visibility.