The elbow: Anatomy and Pathology of Collateral Ligaments using MRI.

Transcription

1 The elbow: Anatomy and Pathology of Collateral Ligaments using MRI. Award: Magna Cum Laude Poster No.: C-0570 Congress: ECR 2018 Type: Educational Exhibit Authors: J. Acosta Batlle, M. D. Lopez Parra, B. Palomino Aguado, J. Pérez-Templado, J. M. Blanc, O. Sanz de León; Madrid/ES Keywords: Pathology, Education, MR, Musculoskeletal joint DOI: /ecr2018/C-0570 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 44

2 Learning objectives 1. To provide a comprehensive review of the normal anatomy and the biomechanics aspects of the medial and lateral collateral ligaments. 2. To highlight important technical aspects that optimise visualitation of anatomic structures. 3. To explain the spectrum of MRI findings of traumatic and overuse injuries. Page 2 of 44

3 Background 1. Technical aspects. Elbow MRI protocols recommended for each diagnostic suspicion. Normal anatomy and biomechanical aspects of the joint capsule and collateral ligaments. Medial collateral ligament complex. Lateral collateral ligament complex. 2. Pathophyfisiology. Valgus and varus instability. Posterolateral rotatory instability and elbow dislocation. 3. Review of imaging findings. 4. Sample cases and mimics. Page 3 of 44

4 Findings and procedure details A) PULSE SEQUENCES 1. Patient supine with the affected arm by the side of the body, elbow extension, and forearm in supination. 2. Surface coils. 3. Matrix: 256 x 192 or 256 x Fov: cm. 5. Axial: slice thickness 4 mm Fig. 1 on page Coronal and sagittal: slice thickness 3 mm Fig. 1 on page A 20 degrees posterior oblique coronal plane in relation to the humeral shaft with the elbow extended or a coronal plane aligned with the humeral shaft with the elbow slightly flexed (20-30 degrees of flexion) Fig. 2 on page MR arthography: axial, coronal and sagittal FS T1 FSE, and Coronal FS T2 FSE or STIR. B) NORMAL ANATOMY a) Collateral Ligements Complex Fig. 3 on page 12 : b) Collateral Lateral Ligament Complex Lateral ulnar collateral ligament (LUCL) Fig. 4 on page 13. Page 4 of 44

5 o LUCL wraps around the posterior aspect of the radial neck. o Origin: Lateral epicondyle (indistinguishable origin of RCL). o Insertion: Supinator crest of the ulna. Radial collateral ligament (RCL) Fig. 5 on page 14. o Origin: Lateral epicondyle (indistinguishable origin of LUCL). o Insertion: Anterolateral aspect of the anular ligament. Annular ligament (AL) Fig. 6 on page 15. o AL encircles the periphery of the radial head). o Origin: Anterior margin of the semilunar notch. o Insertion: Supinator crest of the ulna. Accessory collateral ligament. c) Collateral Medial Ligament Complex Anterior bundle (A-MCL) Fig. 7 on page 16. o The A-MCL is the main stabilizer against valgus and internal rotation stress. o Origin: The undersurface of the medial epicondyle. o Insertion: Sublime tubercle of the ulna. Posterior bundle (P-MCL) Fig. 8 on page 17. o The P-MCL is the floor of the cubital tunnel. o Origin: Posterior aspect of the medial epicondyle. Page 5 of 44

6 o Insertion: Medial aspect of the olecranon process. o During elbow flexion the arcuate ligament tenses and P-MCL relaxes. o 40% of throwing athletes with medial instability have ulnar neuropathy. Transverse ligament (T-MCL). C) LATERAL COLLATERAL COMPLEX INJURY 1. The collateral lateral ligement compplex resist excesive varus and external rotacional stress. 2. LUCL is the most important in terms of stability. 3. Tears can involve one or more of the three bundles. 4. LUCL tears usually involve the humeral origin. 5. Pathology: A fall on an outstretched hand. Iatrogenic injury during release or repair of lateral epicondylitis. Advanced cases of tennis elbow. 6. Characteristic bone bruises: Posterior capitellum. Radial head. 7. Failure to recognize radial collateral complex tears prior to surgical treatment of tennis elbow will lead to persistent postoperative symptoms. Page 6 of 44

7 a) Posterior Dislocation Injury and Instability Posterolateral rotary instability (PLRI) is the most common pattern of recurrent elbow instability Fig. 9 on page 18, Fig. 10 on page 19, Fig. 11 on page 20, Fig. 12 on page 21, Fig. 13 on page 22, Fig. 14 on page 29. Stage 1 Fig. 15 on page 23. Posterolateral subluxation of the ulna on the humerus. Insufficiency or tearing of LUCL. Stage 2 Fig. 16 on page 24. The elbow dislocates incompletely. Tearing of LUCL and RCL. Anterior and posterior capsule are disrupted. Stage 3 The elbow dislocates completely. Tearing of LUCL, RCL and articular capsule. The A-MCL is intact (Stage 3A). The A-MCL is disrupted (Stage 3B) Fig. 17 on page 25, Fig. 18 on page 26. Entire distal humerus is stripped of soft tissues (Stage 3C). b) Posterior Dislocation and Chronic Annular Ligament Injury Fig. 19 on page 27. Recurrent painful click. Differential diagnosis Fig. 20 on page 28 : Page 7 of 44

8 1 Intraarticular bodies. 2 Posterolateral plica. 3 Ulnar nerve subluxation. 4 Snapping tríceps. Pathology: o Adult injury: Varus elbow stress, elbow dislocation, PLRI. o Children: Nursemaid s elbow. D) MEDIAL COLLATERAL COMPLEX INJURY: 1. Medial joint stability to valgus stress. 2. Anterior bundle is the main static stabilizer. 3. Injury mechanism: 1. Chronic microtrauma from repetitive valgus stress (overhead throwing sports). Medial elbow tension overload, lateral compression and extension overload. Baseball, football, javelin throwing, voleyball, golf, polo. Medial elbow pain and valgus instability. 2. After a fall on an outstretched hand. 4. Strain of the flexor digitorum superficialis frequently accompanies an MCL injury. Page 8 of 44

9 5. MRI acute tear: Hyperintensity, discontinuity, and soft tissue edema. 6. MRI chronic tear: Thickening, abnormally signal, and discontinuity. 7. Lateral compartment bone bruises suggest MCL disruption. a) Acute Anterior Bundle of Medial Collateral Ligament Complex: Case 1: A 23-year-old man with pain and medial instability after a fall on the outstretched arm Fig. 21 on page 33.. Case 2: A 32-year-old man with pain and medial instability after a fall on the oustretched arm Fig. 22 on page 36 b) Acute Posterior Bundle of the Medial Collateral Ligament Complex: Case 3: A 25-year-old man with pain and medial instability after a fall on an outstretched hand Fig. 23 on page 34. c) Avulsion Fracture of the Medial Epicondyle: Case 4: A 45-year-old woman with pain, muscle weakness and paresthesias after a fall on an outstretched hand Fig. 24 on page 35. d) Repeated Valgus Stress. Overhead Athlete Fig. 25 on page 40, Fig. 26 on page 30, Fig. 27 on page 31, Fig. 28 on page 32. e) Chronic A-MCL Injury often is associated with valgus extension overhead or posteromedial impingement (valgus stress Page 9 of 44

10 during throwing). o Case 5: A 35-year-old voleyball player with chronic elbow pain and medial instability. Fig. 29 on page 37. o Case 6: A 40-year-old golf player with medial elbow pain and valgus instability. Fig. 30 on page 38. f) Little Leaguer s Elbow ( medial epicondyle apohysitis) Fig. 31 on page 39 : o Chronic stress injure medial epicondylar physis from repetitive traction on the apophysis by the common flexor tendon and MCL (valgus stress during throwing). o Significant elbow injures may occur in the absence of joint effusion in clildren. o Although the ulnar collateral ligament may be sprained with valgus injures, it may normally show increased SI on fluid sensitive sequences in children due to increased elastin content in the anterior fibers compared with adults. Page 10 of 44

11 Images for this section: Fig. 1 Page 11 of 44

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42 Conclusion 1. Anatomical and biomechanical knowledge of the support structures that provide stability to the medial and lateral elbow is essential to correcly interpret the pathological findings. 2. The anterior band of the collateral medial ligament complex is the main stabilizer against valgus and internal rotation stress. 3. The collateral lateral ligement complex resist excesive varus and external rotacional stress. The LUCL is the most important in terms of stability. 4. Conventional MRI and MR artrography are the imaging modality of choice. 5. The most common pattern of recurrent elbow instability is PLRI. Page 42 of 44

43 Personal information Dr. José Acosta Batlle. Universitary Ramón y Cajal Hospital. University of Alcala Henares. Madrid. Spain. jacostabatlle@yahoo.es Page 43 of 44

44 References 1. Stein JM, Cook TS, Simonson S et al (2011). Normal and variant anatomy of the elbow on magnetic resonance imaging. Magn Reson Imaging Clin N Am 19(3): Seki A, Olsen BS, Jensen SL et al (2002). Functional anatomy of the lateral collateral ligament complex of the elbow: configuration of Y and its role. J Shoulder Elb Surg 11(1): Beckett KS, Mc Connell P, Lagopoulos M et al (2000). Variations in the normal anatomy of the collateralligaments of the human elbow joint. J anat 197(Pt3): Kijowski RM, Tuited M, Stanford M (2005). Magnetic resonance imaging of the elbow. Part II: abnornalities of the ligaments, tendons, and nerves. Skelet Radiol 34(1): Anderson MW, alford BA (2010). Overhead throwing injures of the shoulder and elbow. Radiol Clin N Am 48(6): Simon Blease, David W Stoller, Marc R Safran, Arthur E Li, and Russell c Fritz. The elbow. Magnetic Resonance Imaging in Orthopaedics and Sports Medicine. D W. Stoller. Lippincott Williams and Wilkins. Volume two Hang DW, Chao CM, Hang YS (2004). A clinical and roentgenographic study of little league elbow. Am J Spots Med 21: Page 44 of 44