Noncontrast MRI of Shoulder Instability ISMRM 2008

Hollis G. Potter, MD

Chief, Magnetic Resonance Imaging Director of Research, Dept. of Radiology & Imaging

Hospital for Special Surgery Professor of Radiology

Weill Medical College of Cornell University

High Resolution Noncontrast MRI of Shoulder Instability • High spatial resolution 273µ x 390µ (1.5T) x 360µ (3T) x 3mm/0 gap • Moderate TE FSE (28-34) accentuates inherent magnetization transfer contrast • Strict attention to imaging technique imperative • Consider optimized noncontrast imaging as an alternative to intra-articular

contrast: – Visualize “native” capsule – Preserves MRI as noninvasive – Reduced cost – Increased patient throughput; increased unit productivity – Same images sensitive for cartilage, ligament and labral pathology

14 year-old girl with mild cuff tendinosis

45 year-old with a Buford complex and a superior labral tear above

17 year-old with meniscoid variant

Anteroinferior labral tear (Bankart) with articular cartilage disruption

Normal SGHL

16 year old with previous anterior dislocation

70 year old with painful shoulder and limited ROM after a fall

Cuff contusion and Bankart lesion

27 year-old with subacute injury and subtle bone involvement

Bankart with ganglion dissecting into rotator cuff

24 year-old S/P old anterior dislocation

29 year-old 4 days post diving accident Anterior labral periosteal sleeve avulsion (ALPSA) and posterior capsule tear

Posterior instability

Posterior instability

30 year-old fell one month prior with pain and inability to lift arm Posterior Bankart, posterior capsule injury and humeral chondral shearing injury

Lateral avulsion of posterior capsule in a 16 year-old

17 year-old with subacute trauma

Cuff contusion. Contusion greater tuberosity. Anterior capsular stripping at humerus off pouch.

16Y M with HAGL, debris in axillary pouch, SLAP

tear and bare area of glenoid Humeral Avulsion of Glenohumeral Ligaments (HAGL)

Wolf et al (Arthroscopy 1995; 11:600-607) 64 shoulders with a diagnosis of anterior instability 6/64 (9.3%) with HAGL lesions more commonly repaired with open techniques than with arthroscopic ones,

although both have been described

25 year-old man with anterior dislocation 6 weeks prior with new injury

13 year old hurt shoulder while wrestling.

Sensitivity Specificity Anterior 37/37 63/63 100% 95% Superior 31/36 67/67 86% 100% Posterior 14/19 80/84 74% 95%

All 89% 97%

ACCURACY OF NONCONTRAST MR IN LABRAL INJURY

Prospective data collection in 103 Patients; surgical Confirmation 2 independent observers

Radiology 1996; 200:519-524 Kappa statistic (interobserver) for all labral tears was 0.86 (p=0.0001)

3T imaging of shoulder instability • Correction for signal inhomogeneity necessary (coil sensitivity

profile or postprocessing algorithm) • Sample at wider RBW • Increased SNR permits higher in/through plane resolution • Accuracy: Magee and Williams AJR 2006;187: 1448-1452.

– 67 pts with arthroscopic correlation – Sens/spec for SLAP 90/100% – Sens/spec for ALT 89/100% – Sens/spec for PLT 86/100%

Classification of SLAP lesions (Snyder et al 1990)

• Type I : fraying without detachment • Type II : type I plus stripping of superior labrum and biceps off

glenoid • Type III : bucket handle tear of superior labrum with central

displacement and intact biceps • Type IV: type III plus extension into biceps anchor

MGHL tear. Anterior labral tear and anterior capsular tear.

SLAP

SLAP

22 year-old professional athlete with a superior labral tear

17 year old with Type IV SLAP

Superior Labral Lesions: Noncontrast MRI AJSM 1999; 27:208-213

• 100/102 superior labral tears were prospectively identified by MRI

• 2 false negatives (SLAP I, SLAP II lesions) • 4 false positives (1 normal, 2 meniscoid, 1 sublabral

foramen) • MRI:

– sensitivity 98% (100/102) – specificity 89% (34/38) – accuracy 96% (134/140)

41 year old man

Dysplastic glenoid with posterior labral tear & ganglion

Imaging the Throwing Athlete

• Chronic repetitive microtrauma and excessive load leads to plastic deformation of collagen in tendons, capsule and ligaments

• Increased mobility of water • Utility of fast spin echo techniques: assess gray scale of collagen • Tendinosis vs. partial tear vs. cuff delamination • Importance in assessing the degree of scar remodeling of ligaments • Acute on chronic injury

Internal Impingement

• Impingement between the articular side of the rotator cuff and the posterosuperior edge of the glenoid cavity with abduction and external rotation (Walch et al, JSES 1992)

• Injury occurs during early acceleration phases of throwing: rapid internal rotation

• Partial thickness tear RTC articular side • MRI: Periosteal new bone formation/ossification of the posterior

capsule/triceps attachment to scapula (Bennett) • Posterior capsule contracture (GIRD)

16 year-old pitcher with internal impingement

RTC delamination in a 37 year-old athlete

9 year-old pitcher with pain and weakness

Partial cuff tear with glenohumeral cartilage loss

44 year-old with 4 part humeral fracture

Absence of anterior humeral cx artery; thrombosis axillary vein; stretched but intact

posterior humeral cx artery

Imaging of the postoperative shoulder: Noncontrast strategies • Minimize susceptibility artifact caused by metallic fixation • Utility of fast spin echo techniques: limit signal loss due to diffusion • Avoid frequency selective fat suppression techniques: create more field

disturbance and poor image quality (use fast STIR) • Avoid gradient echo techniques: no correction for field inhomogeneity • Assess native synovium

– Infection – Inflammatory response to bioabsorbable fixation

Bankart repair and capsular shift 10/97: now with new instability

19 year-old man with new injury; 6 months following Bankart repair

Cuff contusion with new tear 2-5 o’clock

17 year-old S/P recent open anterior stabilization with new trauma

8 months post bioabsorbable tack fixation

25 year-old 6 months S/P superior labral repair with

bioabsorbable tacks

45 year old man. Prior tack stabilization with displaced tack in rotator interval

19 year-old woman 2 years S/P bioabsorbable tack labral repair with pain and stiffness

Previous labral repair. Bioabsorbable tack protruding into supra/spino glenoid notch

adjacent to suprascapular nerve

12/7/01 3/9/04

19 year-old man S/P stabilization

32 year-old man with tack eroding cartilage and secondary synovitis

33 year-old S/P open stabilization x 2 with thermal capsular shrinkage

Previous thermoplication High Resolution Noncontrast MR Imaging

• Strict attention to imaging technique imperative • Inflammatory synovitis may reflect mode of fixation in

postoperative setting and does not necessarily reflect infection

• Consider optimized noncontrast imaging as an alternative to intra-articular contrast:

– Visualize “native” capsule – Preserves MRI as noninvasive – Reduced cost – Increased patient throughput; increased unit productivity – Same images sensitive for cartilage, ligament and labral pathology

References 1. Connell DA, Potter HG, Wickiewicz TL, Altchek DA, Warren RF. High resolution

magnetic resonance imaging of superior labral pathology: 102 surgically-confirmed cases. Am J Sports Med 1999; 27(2):208-213.

2. D’Alessandro DF, Bradley JP, Fleischli JE, Connor PM. Prospective evaluation of

thermal capsulorrhaphy for shoulder instability. Am J Sports Med 2004; 32:21-33. 2. Deutsch A, Altchek DW, Veltri DM, Potter HG, et al. Traumatic tears of the

subscapularis tendon: clinical diagnosis, magnetic resonance imaging findings, and operative treatment. Am J Sports Med 1997; 25(1):13-25.

3. Gusmer PB, Potter HG, Schatz J, Wickiewicz TL, Altchek DW, O’Brien SDJ,

Warren RF. Labral injuries: accuracy of detection with unenhanced MR imaging of the shoulder. Radiology 1996; 200:519-524.

4. Iannotti JP, Zlatkin MB, Esterhai JL, et al. Magnetic resonance imaging of the

shoulder: sensitivity, specificity and predictive value. J Bone Joint Surg 1991; 73:17-29.

5. Kjellin I, Ho CP, Cervilla VC, et al. Alterations in the supraspinatus tendon at MR

imaging: correlation with histopathologic findings in cadavers. Radiology 1991; 181:837-841.

6. Magee TH, Williams D. Sensitivity and specificity in detection of labral tears with

3.0T MRI of the shoulder. AJR 2006; 187:1448-1452. 7. Nevaiser TJ. The GLAD lesion: another cause of anterior shoulder pain.

Arthroscopy 1993; 9:22-23. 8. O’Brien SJ, Neves MC, Arnoczky SP, et al. The anatomy and histology of the

inferior glenohumeral ligament complex of the shoulder. Am J Sports Med 1990; 18(5): 449-456.

9. Palmer We, Brown JH, Rosenthal DI. Labral-ligamentous complex of the shoulder:

evaluation with MR arthrography. Radiology 1994; 190:645-651. 10. Potter HG. Magnetic resonance imaging of the unstable shoulder. Techniques in

Shoulder and Elbow Surgery 2000; 1(1):25-38. 11. Potter HG. Radiographic Assessment of Shoulder Instability: MRI. In: Warren RF,

Craig EV, and Altchek DW, Eds. The Unstable Shoulder. Philadelphia: Lippincott Raven, 1999; 121-131.

12. Snyder SJ, Karzel RP, Del Pizzo W, et al. SLAP lesions of the shoulder. Arthroscopy 1990; 6(4):274-279.

13. Walch G, Boileau P, Noel E, Donell ST. Impingement of the deep surface of the

supraspinatus tendon on the posterosuperior glenoid rim: an arthroscopic study. JSES 1992; 1:238-245.

14. Williams NM, Snyder SJ, Buford D. The Buford complex--the cordlike middle

glenohumeral ligament and absent anterosuperior labrum complex: A normal anatomic capsulolabral variant. Arthroscopy 1994; 10:241-247.

15. Wright RW, Paletta GA. Prevalence of the Bennett lesion of the shoulder in major

league pitchers. Am J Sports Med 2004; 32:121-124.