A new dynamic technique for assessing acromio-clavicular joint instability with ultrasound Poster No.: C-596 Congress: ECR 2009 Type: Educational Exhibit Topic: Musculoskeletal Authors: P. Peetrons; Brussels/BE Keywords: A-C joint instability, ultrasound, Tossy I lesions, ultrasound DOI: 10.1594/ecr2009/C-596 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. www.myesr.org Page 1 of 9
Learning objectives Ultrasound is able to see dynamic changes in the relation between acromion and clavicle in A-C joint sprains, using a simple clinical test, named crossarm adduction. The patient is asked to put his (her) hand on the opposite shoulder while the ultrasonographer looks to the injured A-C joint. In normal cases, there is no or very slight narrowing of the joint during the test. In grade I (according to Tossy or Rockwood classification), the clavicle will move towards and onwards the acromion. This movement is due to tears in the intrinsic acromioclavicular ligaments in mild sprains. In major grades (Tossy or Rockwood II and III grades), the movements will be much more important, resulting in a lifting of the clavicle at rest and a narrowing of the joint in crossarm maneuver. Background Actually, acromio-clavicular sprains are diagnosed clinically and/or by X-rays, including stress maneuvers. The normal acromio-clavicular distance (A-C) is 0.3-0.8 cm and the normal coracoclavicular (C-C) distance of 1.0-1.3 cm on an A-P X-ray view There are 2 major classifications of A-C joint injuries. Tossy classification is in 3 grades: - Grade I : Sprain limited to acromio-clavicular ligaments. No or minor radiological anomaly (slight augmentation of the A-C distance possible) - Grade II: A-C distance between 1,0 and 1,5 cm, C-C distance enlarged by 25 to 50%, elevation of the clavicle by less than 5 mm on stress view - Grade III: A-C distance over 1,5 cm, enlargement of C-C distance by more than 50% and elevation of the clavicle by more than 5 mm on stress view Rockwood classification adds 3 grades which are posterior dislocation of the clavicle (grade IV), important prolapse of the acromion (Grade V) and anterior dislocation of the clavicle (Grade VI) Minor Grade I and II A-C joint sprains can lead to chronic pain in 27% of the patients, leading sometimes to surgical repair and 50% of these minor sprains however leads to antero-posterior instability (Mouhsine et al.). Page 2 of 9
As X-rays may be falsely negative in Grade I sprains, there is a place for other technique such as ultrasound to show this pathology. Imaging findings OR Procedure details While holding the probe on the presumed injured A-C joint, the ultrasonographer asks the patient to move his (her) hand from a resting position (along the body) to the opposite shoulder. This movement, called crossarm maneuver, is seen in Movie 1. In normal shoulders, there are no or very mild movements between the 2 bones but no elevation of one bone regarding the other. In mild Tossy I sprains, clavicle is clearly out of line regarding the acromion during the maneuver. The movements are well seen on Movies 2 and 3. In fact, the best alignement occurs when the arm is in adduction and worst when the arm is resting along the body. In moderate to severe sprains, the distance between acromion and clavicle are best seen at rest but can be completely reduced while performing crossarm leading to a confirmation of the adduction position to achieve the treatment (Movies 4 and 5) Images for this section: Page 3 of 9
Fig. 1: The patient is asked to put the hand from the injured side to the opposite shoulder Page 4 of 9
Fig. 2: In mild sprain, abnormal movement between the clavicle and the acromion can be seen while performing the test Page 5 of 9
Fig. 3: Another example of mild movements between clavicle and acromion Page 6 of 9
Fig. 4: In moderate sprain like Tossy II, there are already large movements between acromion and clavicle as shown in this movie Page 7 of 9
Fig. 5: In larger sprain, extreme movements as well as dealignation of the bones can be seen Page 8 of 9
Conclusion In conclusion, when suspecting a Tossy I A-C joint sprain, it is possible to assess the injury by performing a simple test during live examination in ultrasound. Even if stress maneuvers using X-rays are negative, ultrasound will show abnormal movements between the two bones. Ultrasound seems more accurate than any other modality thanks to this unique dynamic investigation. Personal Information Prof. Dr. Philippe Peetrons Hôpitaux IRIS Sud 142, rue Marconi 1190 Brussels, BE ppeetrons@bigfoot.com References 1) Mouhsine E, Garofalo R, Crevoisier X, Farron A.Grade I and II acromioclavicular dislocations: esults of conservative treatment. J Shoulder Elbow Surg. 2003 Nov- Dec;12(6):599-602. 2) Tossy JD, Mead NC, Sigmond HM. Acromioclavicular separations: useful and practical classification for treatment. Clin Orthop Relat Res. 1963;28:111-9 3) Rockwood CA Jr. The shoulder: facts, confusions and myths.int Orthop. 1991;15(4):401-5. 4) Peetrons P., Bedard J. Acromioclavicular joint injury: enhanced technique of examination with dynamic maneuver. J Clin Ultrasound 2007 Jun;35(5):262-7 Page 9 of 9