Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content ++ Separated ShoulderAC separationAC dislocationShoulder separation ++ 840.0 Acromioclavicular (joint or ligament) sprain831.04 Closed dislocation of acromioclavicular (joint)831.14 Open dislocation of acromioclavicular (joint) ++ S43.109A Unspecified dislocation of unspecified acromioclavicular joint, initial encounterS43.50XA Sprain of unspecified acromioclavicular joint, initial encounter ++ 4E: Impaired Joint Mobility, Motor Function, Muscle Performance, and Range of Motion Associated With Localized Inflammation +++ Description ++ Inflammation, irritation, or separation of the joint between the clavicle and acromion (AC joint)Three ligaments of stabilityAcromioclavicular ligament Coracoacromial ligamentCoracoclavicular ligament: made up of the conoid ligament and trapezoid ligament +++ Essentials of Diagnosis ++ Diagnosis is made by history and clinical exam and x-rayOccurs most often from falling on an outstretched arm or handAC separation occurs when the ligaments are completely torn and there is a dislocation of the jointSeparation of the clavicle and acromion can be felt upon palpationStep deformity often noticed when the clavicle is raised due to ligament tearingSix grades of sprain to separation: Rockwood scaleGrade I Slight displacement of the jointPartially torn AC ligamentSeparation < 4mmGrade IIPartial dislocation of the jointComplete disruption tear of the AC ligamentPartial disruption of the coracoclavicular ligamentSeparation > 5mmGrade IIIPartial dislocation of the jointComplete disruption tear of the AC ligamentComplete disruption/rupture of the coracoclavicular ligamentGrade IVDislocation of the jointPosterior displacementRequires surgeryGrade VDislocation of the jointSuperior displacementRequires surgeryGrade VIDislocation of the jointInferior displacementRequires surgery +++ General Considerations ++ No synovial jointOsteoarthritis is common without treatment or with prolonged instability +++ Demographics ++ Predominately in individuals with a history of activities involving overhead reach: swimming, tennis, and baseball as well as with occupational activities involving repetitive overhead activity +++ Signs and Symptoms ++ Ache in the anterior top aspect of the shoulder Frequently worsens with overhead lifting or activityPain with palpation at AC jointStep deformity of the clavicle and acromionOccasional sound or sensation of snappingPain with traction on the arm +++ Functional Implications ++ May limit overhead activities, especially liftingMay limit throwing and other rapid arm movements +++ Possible Contributing Causes ++ Frequent and prolonged overhead activity Prolonged repetitive use of the involved armPoor posture (i.e., rounded shoulders)Anterior displacement of the humeral headRotator cuff weaknessFall on outstretched handLanding on lateral tip of the acromion +++ Differential Diagnosis ++ Rotator cuff tendinitisRotator cuff impingementRotator cuff tearSubacromial bursitisBicep tendinopathyBicep tearLabral tear +++ Imaging ++ Radiographs while patient ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.