Acute Acromioclavicular Dislocation

​Acute Acromioclavicular Dislocation: Epidemiology, Natural History and Analysis of Prognostic Factors - A prospective cohort study

Primary Investigator

Kristine B. Andersen, MD, PhD student1,2

Senior Researcher

Kristoffer W. Barfod, MD, PhD1,2

Study members

Klaus Bak, MD, Chief Surgeon3, Dorthe Ryberg, PT2, Omar Muharemovic, Radiographer4, Per Hölmich, MD, Chief Surgeon, Professor1,2


  1. Sports Orthopedic Research Center – Copenhagen, Department of Orthopedic Surgery, Copenhagen University Hospital Hvidovre, Denmark.

  2. Department of Orthopedic Surgery, Copenhagen University Hospital Hvidovre, Denmark.

  3. Kysthospitalet, Skodsborg

  4. Department of Radiology, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre.

About the study/project

Acromioclavicular (AC) joint dislocations are common injuries accounting for 9-12% of all injuries to the shoulder girdle. The injuries are graded according to Rockwoods classification type I-VI. There is consensus on the treatment of Rockwood type I and II, which rehabilitates well with conservative treatment, and for high-grade injuries of types IV, V and VI, which usually requires surgery. However the treatment of the most common type, type III, remains controversial.

Most patients with type III AC dislocation rehabilitate well with conservative treatment, however, some patients continue to have pain and functional limitations long after their injury. With this study, the investigators aim to evaluate a sub-classification of the debated type III in a stable type IIIA, that will rehabilitate well with conservative treatment, and an unstable type IIIB, that might benefit from early surgical intervention.

The study is a prospective cohort study carried out at Copenhagen University Hospital Hvidovre. 100 patients aged 18-60 years with acute traumatic AC dislocation will be recruited from the Emergency Departments at three hospitals in the Capitol Region of Denmark. Patients are treated non-operatively with a 3 months physiotherapy program especially designed for AC joint dislocations. Patients are assessed at baseline and at 6 weeks, 3 months, 6 months and 1 year after the injury. The primary endpoint is the Western Ontario Shoulder Instability Index at 3 months. Secondary endpoints are the Shoulder Pain and Disability Index, the cosmesis evaluated on a NRS scale, and range of motion.

The following Clinical tests are investigated for association with the outcomes: scapular dyskinesia, horizontal and vertical instability of AC joint and O'Briens test. The following radiological measurements are investigated for association with the outcomes: coraco-clavicular distance and horizontal translation of the clavicle.

Inclusion for the study started in December 2018 and is suspected to end in April 2020.

Purpose of the study/project

To evaluate non-operative treatment of acute acromioclavicular joint dislocation and define prognostic factors to guide the choice of treatment in order to develop an individualized treatment algorithm. Identifier


Responsible editor