Radiological Category Musculoskeletal Principal Modality 1 General Radiography

  • Slides: 16
Download presentation
Radiological Category: Musculoskeletal Principal Modality (1): General Radiography Principal Modality (2): MRI Case Report

Radiological Category: Musculoskeletal Principal Modality (1): General Radiography Principal Modality (2): MRI Case Report #0480 Submitted by: Ravi Bodiwala, M. D. Faculty reviewer: Manickam Kumaravel, M. D. Date accepted: 11 March 2008 Permission requested regarding display of Figures 5, 6 and 7. Please refer to reference for details.

Case History 24 year old male basketball player who reports of left shoulder pain

Case History 24 year old male basketball player who reports of left shoulder pain since being struck on his arm by an opposing player. He has history multiple prior left shoulder subluxation.

Radiological Presentations Figure 1: AP view of the left shoulder in external rotation.

Radiological Presentations Figure 1: AP view of the left shoulder in external rotation.

Radiological Presentations Figure 2: Axial T 1 fat suppressed image at the level of

Radiological Presentations Figure 2: Axial T 1 fat suppressed image at the level of the inferior glenoid.

Radiological Presentations Figure 3: Axial PD fat suppressed image at the level of the

Radiological Presentations Figure 3: Axial PD fat suppressed image at the level of the inferior glenoid.

Radiological Presentations Figure 4: Coronal PD fat suppressed image.

Radiological Presentations Figure 4: Coronal PD fat suppressed image.

Test Your Diagnosis Which one of the following is your choice for the appropriate

Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Bankart lesion • Perthes lesion • ALPSA (Anterior labroligamentous periosteal sleeve avulsion) • GLAD (Glenolabral articular disruption) lesion

Findings and Differentials Findings: The general radiograph of the shoulder shows no fracture or

Findings and Differentials Findings: The general radiograph of the shoulder shows no fracture or dislocation. On the axial T 1 and proton density fat suppressed images, there is a linear region of contrast (tear) involving the anteroinferior glenoid labrum that tracks into the adjacent glenoid cartilage. The abnormality affecting the anterorinferior glenoid cartilage is better seen on the coronal PD image. Of note, the anterior labroligamentous complex and scapular periosteum appear intact. Incidental note is made of a tear involving the posteroinferior labrum. Axial proton density image demonstrates a small area of bone edema involving the anterior humeral head. Differentials: • GLAD (Glenolabral articular disruption) lesion • Bankart lesion • Perthes lesion • ALPSA (Anterior labroligamentous periosteal sleeve avulsion)

Discussion Anterior stability of the shoulder is largely dependent on the integrity of the

Discussion Anterior stability of the shoulder is largely dependent on the integrity of the anterior labroligamentous complex, which is composed of the inferior glenohumeral ligament and the anteroinferior labrum. Please refer to Figure 5, for a graphic demonstration of stable and unstable abnormalities involving the anterior inferior labrum. This was a case of a Glenolabral articular disruption (GLAD) lesion. A GLAD lesion was first described by Neviaser as a superficial tear of the anteroinferior labrum, with an associated injury of the adjacent glenoid articular cartilage (see Figure 6). The mechanism of injury is a fall on an outstretched arm, which results in an impaction of the humeral head against the articular surface of the glenoid fossa. GLAD is an important radiologic diagnosis since these patients do not show signs of anterior instability on physical exam. The cartilage tear associated with a GLAD lesion (see Figure 7) can be a flap tear or a more focal defect, which may produce loose joint bodies. A GLAD lesion is treated with arthroscopic debridement and chondroplasty, or abrasion arthroplasty. The recovery time is usually 3 months, with a majority of patients reporting post-surgical symptomatic relief.

Discussion Bankart lesion: A Bankart lesion consists of a frank avulsion of the anteroinferior

Discussion Bankart lesion: A Bankart lesion consists of a frank avulsion of the anteroinferior labrum from the glenoid. In this lesion, the scapular periosteum that attaches the labrum to the glenoid is torn, while the anterior band of the inferior glenohumeral ligament maintains its relationship with the glenoid (see Figure 5). Distinguishing a GLAD lesion from a Bankart lesion is important because of the difference in surgical management between these two lesions. A GLAD lesion does not produce shoulder instability, and therefore it is treated with arthroscpoic debridement without the need for a stabilization procedure. A Bankart lesion, on the other hand, is treated with repair of the anterior labroligamentous complex to restore shoulder stability. Incidental note was made of a reverse Bankart (posterior inferior glenoid) injury in this patient who had recurrent shoulder dislocations. Perthes lesion: A perthes lesion refers to a non-displaced avulsion injury of the anteroinferior portion of the glenoid labrum, with associated stripping of the scapular periosteal membrane (see Figure 5). This lesion is difficult to detect on both imaging and arthroscopy, as the periosteum remains attached to the glenoid medially. The clinical implications of this injury are similar to those of a Bankart lesion.

Discussion Anterior labroligamentous periosteal sleeve avulsion: ALPSA is another cause of anterior shoulder instability.

Discussion Anterior labroligamentous periosteal sleeve avulsion: ALPSA is another cause of anterior shoulder instability. This lesion is characterized by an avulsion of the anteroinferior labrum, which is pulled medially by an intact anterior scapular periosteum (see Figure 5). It is is an important radiologic diagnosis as these lesions can be missed arthroscopically. In summary, accurate radiologic diagnosis of labroligamentous shoulder injuries is important for successful patient management. Recent advances in MR imaging have made MR arthrography the modality of choice for assessment of the glenohumeral joint, especially in patients with shoulder instability. As discussed earlier, many lesions may be difficult to see on arthroscopy alone, and therefore underscore the importance of pre -operative imaging.

Figure 5: A GLAD lesion is not associated with anterior shoulder instability, as opposed

Figure 5: A GLAD lesion is not associated with anterior shoulder instability, as opposed to a Bankart, Perthes and ALPSA lesions. Please refer to discussion for a review of these entities. Graphic courtesy of Waldt et al. Magnetic Resonance Imaging of Glenohumeral Instability. Fortschr Röntgenstr 2006; 178: 590 -599

Figure 6: Graphic image shows a tear in the anteroinferior labrum, with associated cartilage

Figure 6: Graphic image shows a tear in the anteroinferior labrum, with associated cartilage injury. Of note, the scapular periosteum remains intact. Image courtesy of GLAD LESION: GLENOLABRAL ARTICULAR DISRUPTION: John Hunter's MSK Teaching File: Shoulder Case 46.

Figure 7: Arthroscopic image shows a chondral flap (straight arrows) being lifted away from

Figure 7: Arthroscopic image shows a chondral flap (straight arrows) being lifted away from the underlying bony glenoid (curved arrows). Image courtesy of Sanders et al. The Glenolabral Articular Disruption Lesion: MR Arthrography with Arthroscopic Correlation. AJR. 1999; 172: 171 -175

Diagnosis GLAD (Glenolabral articular disruption) lesion.

Diagnosis GLAD (Glenolabral articular disruption) lesion.

References Robinson G, Ho Y, Finlay K, Friedman L, Harish S. Normal anatomy and

References Robinson G, Ho Y, Finlay K, Friedman L, Harish S. Normal anatomy and common labral lesions at MR arthrography of the shoulder. Clinical Radiology. 2006 Oct; 61(10): 805 -21. Rowan KR, Keogh C, Andrews G, Cheong Y, Forster BB. Essentials of shoulder MR arthrography: a practical guide for the general radiologist. Clinical Radiology. 2004 Apr; 59 (4); 327 -34. Sanders TG, Tirman PFJ, Linares R, Feller JF, Richardson R. The Glenolabral Articular Disruption Lesion: MR Arthrography with Arthroscopic Correlation. American Journal of Roentgenology. 1999; 172: 171 -175 (source of Figure 7). Neviaser TJ. The GLAD lesion: another cause of anterior shoulder pain. Arthroscopy. 1993; 9(1): 22 -3. GLAD LESION: GLENOLABRAL ARTICULAR DISRUPTION: John Hunter's MSK Teaching File: Shoulder Case 46 (source of Figure 6). Waldt S, Rummeny EJ. Magnetic Resonance Imaging of Glenohumeral Instability. Fortschr Röntgenstr 2006; 178: 590 -599 (source of Figure 5).