Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves

Prevalence of triceps tendon tears on MRI of the elbow and clinical correlation

OBJECTIVE

Triceps tendon injuries are reported to be very rare. To our knowledge, there have been no studies describing its prevalence or injury patterns on MR imaging. The purpose of this retrospective study was to determine the prevalence and patterns of triceps injuries based on a large series of consecutive MR examinations. Clinical correlation was obtained.

MATERIALS AND METHODS

From 801 consecutive elbow MR examinations over a 15-year period, 28 patients with 30 triceps tendon injuries were identified and graded as partial tendon tear and complete tendon tear. The patients' medical records were reviewed to determine age, gender, cause of tears, and management.

RESULTS

The prevalence of triceps tendon injuries was 3.8%. There were 5 women and 23 men with partial or complete tears (mean age: 46.6 years; range: 2.7 to 75.1 years). The most common injury was partial tear, found in 18 patients. There were 10 patients with 12 complete tears (2 had re-torn following surgical repair). A tear was suspected in 12 out 28 (43%) patients prior to the MRI. The most common presenting symptom was pain. The most common cause was athletic injury (8 patients [29%], including weightlifting [2 patients]). Tendon tear was found to be a complication of infection in 6 patients, and in 3 patients the tears were a complication of steroid use. Thirteen tendon tears were surgically repaired (8 of these were complete tears).

CONCLUSIONS

Triceps tendon injury is not as rare as commonly reported and may often be clinically underdiagnosed.

Magnetic resonance imaging of the alar and transverse ligaments in acute whiplash-associated disorders 1 and 2: a cross-sectional controlled study

STUDY DESIGN

Cross-sectional.

OBJECTIVE

To describe alar- and transverse-ligament magnetic resonance imaging (MRI) high-signal changes in acute whiplash-associated disorders (WAD) grades 1 and 2 in relation to the severity and mechanics of trauma, and to compare them with controls.

SUMMARY OF BACKGROUND DATA

The alar and transverse ligaments are important stabilizers at the craniovertebral junction. Acute injury of these ligaments should be detected as high-signal changes on high-resolution MRI.

METHODS

In the study, 114 consecutive acute WAD 1-2 patients and 157 noninjured controls underwent upper-neck high-resolution MRI, using proton-weighted sequences and Short Tau Inversion Recovery (STIR). Two blinded radiologists independently graded high-signal changes 0 to 3 on proton images and assessed ligament high-signal intensity on STIR. Image quality was evaluated as good, reduced, or poor (not interpretable). Multiple logistic regression was used for both within- and between-groups analyses.

RESULTS

All proton and STIR images were interpretable. Interobserver agreement for grades 2 to 3 versus grades 0 to 1 changes was moderate to good (κ = 0.71 alar; and 0.54 transverse). MRI showed grades 2 to 3 alar ligament changes in 40 (35.1%) and grades 2 to 3 transverse ligament changes in 27 (23.7%) of the patients. Such changes were related to contemporary head injury (P = 0.041 alar), neck pain (P = 0.042 transverse), and sex (P = 0.033 transverse) but did not differ between patients and controls (P = 0.433 alar; and 0.254 transverse). STIR ligament signal intensity, higher than bone marrow, was found in only three patients and one control.

CONCLUSION

This first study on high-resolution MRI of craniovertebral ligaments in acute WAD 1-2 indicates that such trauma does not induce high-signal changes. Follow-up studies are needed to find out whether pretraumatic high-signal changes imply reduced ligament strength and can predict chronic WAD.

Ultrasound assessment of the lateral collateral ligamentous complex of the elbow: imaging aspects in cadavers and normal volunteers

OBJECTIVE

The Lateral Collateral Ligamentous complex (LCL) is an important stabiliser of the elbow. It has a Y-shaped structure with three components. In this study, we sought to describe the ultrasound aspect of the individual components of this ligamentous complex and to evaluate the performance of ultrasound in both cadavers and in normal subjects.

METHODS

Ten cadaveric elbow specimens underwent high-frequency ultrasound. Two specimens were sliced and two were dissected for anatomical correlation. Ten elbows of normal subjects were also evaluated by ultrasound. The findings were compared.

RESULTS

The three components of the LCL could be visualised in all specimens and normal subjects with the exception of the proximal portion of one specimen. In 80% of the specimens and 100% of the healthy volunteers the proximal portion of the LCL could be separated from the extensor tendons.

CONCLUSION

High-resolution ultrasound can assess all components of the LCL of the elbow and can distinguish them from surrounding structures.

Magnetic resonance imaging of the elbow in athletes

Acute and chronic elbow pain is common, particularly in athletes. Although plain radiographs, ultrasound, and computed tomography all have a role to play in the investigation of elbow pain, magnetic resonance imaging (MRI) has emerged as the imaging modality of choice for diagnosis of soft tissue disease and osteochondral injury around the elbow. The high spatial resolution, excellent soft-tissue contrast, and multiplanar imaging capabilities of MRI make it ideal for evaluating the complex joint anatomy of the elbow. This article reviews imaging of common disease conditions occurring around the elbow in athletes, with an emphasis on MRI.

Prevalence of triceps tendon tears on MRI of the elbow and clinical correlation

OBJECTIVE

Triceps tendon injuries are reported to be very rare. To our knowledge, there have been no studies describing its prevalence or injury patterns on MR imaging. The purpose of this retrospective study was to determine the prevalence and patterns of triceps injuries based on a large series of consecutive MR examinations. Clinical correlation was obtained.

MATERIALS AND METHODS

From 801 consecutive elbow MR examinations over a 15-year period, 28 patients with 30 triceps tendon injuries were identified and graded as partial tendon tear and complete tendon tear. The patients' medical records were reviewed to determine age, gender, cause of tears, and management.

RESULTS

The prevalence of triceps tendon injuries was 3.8%. There were 5 women and 23 men with partial or complete tears (mean age: 46.6 years; range: 2.7 to 75.1 years). The most common injury was partial tear, found in 18 patients. There were 10 patients with 12 complete tears (2 had re-torn following surgical repair). A tear was suspected in 12 out 28 (43%) patients prior to the MRI. The most common presenting symptom was pain. The most common cause was athletic injury (8 patients [29%], including weightlifting [2 patients]). Tendon tear was found to be a complication of infection in 6 patients, and in 3 patients the tears were a complication of steroid use. Thirteen tendon tears were surgically repaired (8 of these were complete tears).

CONCLUSIONS

Triceps tendon injury is not as rare as commonly reported and may often be clinically underdiagnosed.

Detailed MRI-anatomic study of the lateral epicondyle of the elbow and its tendinous and ligamentous attachments in cadavers

OBJECTIVE

The objective of our study was to document discrete bone landmarks in the lateral epicondyle of the humerus that represent the "footprints" of those tendons and ligaments that attach to it using MRI-anatomic correlation in cadavers.

MATERIALS AND METHODS

Thirty-three dried humeral specimens were inspected to document bone landmarks in the lateral epicondyle. MRI with anatomic correlation was performed in 10 additional cadaveric elbows. The locations of the tendinous and ligamentous attachments to the lateral epicondyle were determined with respect to the same osseous landmarks.

RESULTS

The surface of the lateral epicondyle ranged from a flat surface to a surface with up to six discrete landmarks: superior tubercle, anterior tubercle, posterior tubercle, intertubercular sulcus, rough area surrounding the tubercles, and epicondylar ridge. The radial collateral ligament attached to the superior aspect of the intertubercular sulcus and inferior aspect of the superior tubercle and was indistinguishable from the attachment of the lateral ulnar collateral ligament. The extensor carpi radialis brevis, extensor digitorum communis, and extensor digiti minimi had a common origin in the superior aspect of the lateral epicondyle. The extensor carpi ulnaris tendon arose from the posteroinferior aspect of the lateral epicondyle.

CONCLUSION

Our investigation documents osseous landmarks that are useful in the identification of the footprints of the tendons and ligaments that attach to the lateral epicondyle. Knowledge of these structures contributes to correct interpretation of MR images in persons with tendinous and ligamentous abnormalities in this region.

Distal triceps rupture

Distal triceps rupture is an uncommon injury. It is most often associated with anabolic steroid use, weight lifting, and laceration. Other local and systemic risk factors include local steroid injection, olecranon bursitis, and hyperparathyroidism. Distal triceps rupture is usually caused by a fall on an outstretched hand or a direct blow. Eccentric loading of a contracting triceps has been implicated, particularly in professional athletes. Initial diagnosis may be difficult because a palpable defect is not always present. Pain and swelling may limit the ability to evaluate strength and elbow range of motion. Although plain radiographs are helpful in ruling out other elbow pathology, MRI is used to confirm the diagnosis, classify the injury, and guide management. Incomplete tears with active elbow extension against resistance are managed nonsurgically. Surgical repair is indicated in active persons with complete tears and for incomplete tears with concomitant loss of strength. Good to excellent results have been reported with surgical repair, and very good results have been achieved even for chronic tears.

Elbow tendinopathy and tendon ruptures: epicondylitis, biceps and triceps ruptures

Lateral and medial epicondylitis are common causes of elbow pain in the general population, with the lateral variety being more common than the medial by a ratio reportedly ranging from 4:1 to 7:1. Initially thought to be an inflammatory condition, epicondylitis has ultimately been shown to result from tendinous microtearing followed by an incomplete reparative response. Numerous nonoperative and operative treatment options have been employed in the treatment of epicondylitis, without the emergence of a single, consistent, universally accepted treatment protocol. Tendon ruptures about the elbow are much less frequent, but result in more significant disability and loss of function. Distal biceps tendon ruptures typically occur in middle-aged males as a result of an event that causes a sudden, eccentric contraction of the biceps. Triceps tendon ruptures are exceedingly rare but usually have a similar etiology with a forceful eccentric contraction of the triceps that causes avulsion of the tendon from the olecranon. The diagnosis of these injuries is not always readily made. Complete ruptures of the biceps or triceps tendons have traditionally been treated surgically with good results. With regard to biceps ruptures, there continues to be debate about the best surgical approach, as well as the best method of fixation of tendon to bone. This article is not meant to be an exhaustive review of the broad topics of elbow tendinopathy and tendon ruptures, but rather is a review of recently published information on the topics that will assist the clinician in diagnosis and management of these conditions.

What's new in common upper extremity entrapment neuropathies

Upper extremity entrapment neuropathies are common and disabling, and correct diagnosis is essential for proper management. This article is a review of the recent developments related to diagnosis and treatment of common upper extremity nerve entrapments, including novel treatment strategies for suprascapular, median, ulnar, and radial nerve entrapments. When combined with classic peripheral nerve examination techniques, innovations in imaging modalities have led to more reliable diagnoses. Innovations in surgical techniques, such as endoscopic approaches, have been controversial as to their effects on patient outcome, but recent randomized controlled trials have provided important information regarding common operative techniques, particularly with regard to carpal tunnel surgery and ulnar nerve transpositions.

Triceps brachii tendon: anatomic-MR imaging study in cadavers with histologic correlation

OBJECTIVE

The purpose of this cadaveric study was to describe the normal MR anatomy of the triceps brachii tendon (TBT) insertion, to correlate the findings with those seen in anatomic sections and histopathologic analysis, and to review triceps tendon injuries.

MATERIALS AND METHODS

Twelve cadaveric elbows were used according to institution guidelines. T1-weighted spin-echo MR images were acquired in three planes. Findings on MR imaging were correlated with those derived from anatomic and histologic study.

RESULTS

On MR images, the TBT had a bipartite appearance as it inserted on olecranon in all specimens. The insertion of the medial head was deeper than that of the long and lateral heads and was mainly muscular at its insertion, with a small amount of the tendon blending with the muscle distally, necessitating histologic analysis to determine if there was tendon blending with the muscle at the site of insertion and if the medial head inserted together with the common tendon or as a single unit. At histopathologic analysis, the three heads of the triceps tendon had a common insertion on the olecranon. The bipartite aspect of the tendon that was identified in the MR images was not seen by histologic study, indicating that there was a union of the medial and common tendons just before they inserted into bone.

CONCLUSION

TBT has a bipartite appearance on MR images and inserts on olecranon as a single unit.

Ulnar collateral ligament reconstruction

Since the first description of an ulnar collateral ligament (UCL) tear at the elbow 60 years ago and the first description of surgical reconstruction 20 years ago, many advances have been made in management and surgery. UCL tears at the elbow remain a disease of the overhead athlete. Various imaging studies have been used in the diagnosis of UCL tears at the elbow; however, the physical examination and history continue to be the most important tools. This article describes the history and what has been learned as well as the approach to the treatment of UCL tears at the elbow.

Documentation of associated injuries occurring with radial head fracture

We believe a better way is needed to accurately describe the spectrum of associated injuries that commonly occur in conjunction with a radial head fracture. A review of our institution's experience with 333 radial head fractures from 1997 to 2002 documented 88 (26%) associated injuries. Based on this clinical experience, our goal was to develop an accurate and comprehensive description of associated injuries. A shorthand suffix method first recognizes the type of radial head fracture with the traditional Mason classification, followed by abbreviations designating the articular injuries, coronoid (c) and olecranon (o), and the ligamentous injuries, lateral collateral ligament (l), medial collateral ligament (m), and distal radioulnar joint (d). The proposed system offers a logical and reproducible (98%) extension of the current Mason fracture classification to document the presence of additional articular and ligamentous injuries. This provides an opportunity to standardize the communication of fracture type with further details of other injuries that ultimately can help with better understanding of treatment outcome based on the precise injury complex.

MR imaging findings of anterior interosseous nerve lesions

OBJECTIVE

To study and characterise the MR imaging findings of lesions of the anterior interosseous nerve (AIN).

MATERIALS AND METHODS

Magnetic resonance imaging (MRI) findings of the forearm of ten patients referred to our institution with suspected AIN lesions were retrospectively studied. Five healthy volunteers with normal forearm MRI findings formed a control group. Two musculoskeletal radiologists assessed the forearm musculature for oedema in the distribution of the AIN, median, posterior interosseous and radial nerves on T2-weighted (T2W) fat-saturated sequences. T1-weighted (T1W) images were assessed and graded for the presence of muscle atrophy and fatty involution.

RESULTS

Six patients had undergone surgical exploration; five of these had surgically confirmed AIN compression. Four patients had diagnoses other than AIN compression made on imaging features. Of the cases of proven AIN compression, oedema within the pronator quadratus (PQ) muscle was identified in all cases. PQ atrophy and fatty involution were seen in three (43%) surgically confirmed cases. Cases 2 and 3 also demonstrated oedema in the flexor digitorum profundus (FDP)1 and FDP2 muscles. These cases also showed oedema in the flexor-carpi radialis (FCR) and FDP3/FDP4 muscles, respectively. The four cases of non-AIN compression demonstrated muscle oedema patterns that were atypical for the AIN distribution. They included a rupture of the flexor pollicis longus (FPL) tendon, brachial neuritis, amyotrophic lateral sclerosis and compression of the proximal median nerve.

CONCLUSIONS

MRI is a useful investigation in the diagnostic workup of AIN syndrome. AIN syndrome is likely when there is diffuse oedema of AIN innervated muscles on T2W fat-saturated images. The most reliable sign of an AIN lesion is oedema within the PQ. Oedema in the flexor carpi radialis, FDP3 and FDP4, although not in the classical distribution of the AIN, does not preclude the diagnosis of AIN syndrome.

Role of magnetic resonance imaging in musculoskeletal trauma

The unique ability of magnetic resonance (MR) imaging to visualize injuries of bone, cartilage, bone marrow, and supporting soft tissue structure makes it ideally suited for the evaluation of musculoskeletal trauma. Magnetic resonance imaging also offers exquisitely detailed anatomical information on the musculoskeletal system. The widespread availability of MR imaging and the constantly improving technology make it the imaging modality of choice for the patients with a musculoskeletal trauma. This review discusses the role and applications of MR imaging for musculoskeletal trauma. It covers traumatic conditions of the musculoskeletal system, including hemarthrosis, lipohemarthrosis, stress fracture, occult fractures, cartilage injuries, the muscle and tendon trauma, avulsion injuries, extensor mechanism injuries, and traumatic conditions of joints.

Ligament and tendon injury to the elbow: clinical, surgical, and imaging features

Significant advances in the understanding of elbow anatomy, biomechanics, imaging, and surgical technique have been made over the last decade. Tendon injuries are often seen in athletes and physical laborers from repetitive eccentric overload. Ligament injuries are commonly seen in throwing athletes or after elbow dislocation. Magnetic resonance imaging has proven valuable for diagnosing and monitoring most of these soft tissue injuries, and effective surgical techniques have evolved to address them. This article describes typical clinical findings associated with ligament and tendon injuries in the elbow as well as common surgical therapies. The use of magnetic resonance imaging is highlighted throughout because this modality has revolutionized noninvasive evaluation of the elbow.

Reprint of imaging of the elbow: a review of imaging findings in acute and chronic traumatic disorders of the elbow

Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.

Imaging of the elbow: a review of imaging findings in acute and chronic traumatic disorders of the elbow

Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.

Magnetic resonance imaging of the elbow: update on current techniques and indications

The utility of magnetic resonance imaging of the elbow has noticeably improved over the past decade. Advances in equipment and refinement of pulse sequences has allowed for superior visualization of many pathologic processes involving the elbow joint and its surrounding structures. At this time, magnetic resonance imaging is most valuable in detecting occult fractures, osteochondritis dissecans, collateral ligament tears, nonossified intra-articular loose bodies, and soft tissue masses. It may also aid in the diagnosis of tendinous injuries, compression neuropathies, and synovial disorders. This article serves as an educational update for hand surgeons and illustrates the features of normal anatomy and specific disorders of the elbow.

3T MR Imaging of the Musculoskeletal System (Part II): Clinical Applications

The gain in SNR that is afforded by 3T MR imaging systems has tremendous clinical applications in the musculoskeletal system. The potential for demonstrating and enhancing the visibility of normal osseous, tendinous, cartilaginous, and ligamentous structures is exciting. Furthermore, harnessing this added signal to increase spatial resolution may improve our diagnostic abilities in various joints dramatically. Radiologists have enjoyed great success in assessing joint disease with current MR imaging field strengths; however, many intrinsic joint structures remain poorly evaluated, which leads to a golden opportunity for 3T MR imaging. The articular cartilage of the knee, the glenoid labrum of the shoulder, the intrinsic ligaments and TFC of the wrist, the collateral ligaments of the elbow, the labrum and articular cartilage of the hip, and the collateral ligaments of the ankle have been evaluated suboptimally on 1 .5T systems using routine nonarthrographic MR images. Because of the enhanced SNR, the higher spatial resolution, and the greater CNR of intrinsic joint structures at higher field strengths, 3T MR imaging has the potential to improve diagnostic abilities in the musculoskeletal system vastly, which translates into better patient care and management. The author's 2 years of clinical experience with musculoskeletal MR imaging on 3T systems has met and exceeded his expectations, and has bolstered the confidence of his orthopedic surgeons in his diagnoses. As coil technology advances and as the use of parallel imaging becomes more available in the extremities, the author expects to see even more dramatic improvements in image quality.

[MR imaging of tendon diseases. Exemplified using the examples of rotator cuff, epicondylitis and achillodynia]

Diseases of tendons have recently increased in importance. This may be due to the increasing popularity of free time sport, but also to the increasing number of treatment possibilities. The origin of damage to the tendons can be explained by a series of mechanisms, of which reduced tissue perfusion and mechanical irritation with microtrauma, which lead to degeneration, can be considered as the most important. Imaging diagnostics plays a significant role in the diagnosis and planning of the therapy of such illnesses. In addition to the conventional x-ray to determine the position of the joint and bony structures, ultrasound can be used to examine the tendons, bursae and tissue.MRI is an excellent method for examining the pathology of tendons due to its exceptional qualities for imaging tissue and joints as well as its high specificity. Using MRI, it is possible to determine the degree of morphological change, make reproducible examinations, as well as determining comorbidity factors or the reasons for the changes early in the illness. It therefore influences surgical decisions and can play a key role in the planning of operations. MRI arthography can-depending on the question-increase the diagnostic power in cases of alterations in the rotator cuff.