Acromial apophysiolysis: superior shoulder pain and acromial nonfusion in the young throwing athlete
Related Experiment Video
Updated: Apr 22, 2026
Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Johannes B Roedl1, William B Morrison, Michael G Ciccotti
1From the Division of Musculoskeletal Imaging and Interventions, Department of Radiology, Thomas Jefferson University Hospital, Jefferson Medical College, 132 S 10th St, Philadelphia, PA 19107 (J.B.R., W.B.M., A.C.Z.); and Division of Sports Medicine, Department of Orthopedic Surgery, Thomas Jefferson University Hospital, Rothman Institute, Jefferson Medical College, Philadelphia, Pa (M.G.C.).
Purpose:
To describe the frequency of acromial apophysiolysis and its association with incomplete fusion and superior shoulder pain, to determine risk factors of acromial apophysiolysis, and to assess whether acromial apophysiolysis is associated with the development of an os acromiale and rotator cuff tears.
Materials And Methods:
Institutional review board approval was obtained for this HIPAA-compliant study; requirement for informed consent was waived. A retrospective report review of 2372 consecutive patients between 15 and 25 years of age who underwent shoulder magnetic resonance (MR) imaging for shoulder pain was performed. Individuals with edema at the acromial apophyses and no other abnormalities on MR images were included in the study group. Association of acromial edema with incomplete fusion, pitching, and clinical findings was determined in the study group and in an age- and sex-matched control group, with both univariate and multivariate binary logistic regression analyses. Association with the development of an os acromiale and rotator cuff tears later in life was assessed with follow-up imaging after age 25 years.
Results:
Edema at the acromial apophyses was found in 2.6% (61 of 2372) of patients and was associated with incomplete fusion of the acromial apophyses (χ(2), P < .001) and superior shoulder tenderness (P < .001). The entity was named acromial apophysiolysis. A pitch count of more than 100 pitches per week was shown to be a risk factor for acromial apophysiolysis (odds ratio [ OR odds ratio ] = 6.5, P = .017). Follow-up imaging showed that acromial apophysiolysis was significantly associated with the development of an os acromiale ( OR odds ratio = 138, P < .001) and rotator cuff tears ( OR odds ratio = 5.4, P = .015) after age 25 years.
Conclusion:
Acromial apophysiolysis is characterized by incomplete fusion and edema at the acromial apophyses. It is associated with superior shoulder pain in young patients (< 25 years old), and pitching is a risk factor. It predisposes the patient to the development of an os acromiale and rotator cuff tears after age 25 years.
Related Concept Videos
01:23Muscles of the Shoulder
Anterior Thoracic Muscles
The anterior thoracic muscles include the serratus anterior, subclavius, and...
01:31Muscles that Move the Arm
The pectoralis major has two origins. Its clavicular head originates on the medial half of the clavicle. In contrast, the sternocostal head originates on the costal cartilages of ribs 1-6, the sternum, and the aponeurosis of the external oblique of the...
01:19Bones of the Upper Limb: Humerus
01:22Appendicitis-I: Introduction
Etiology: Appendicitis can arise from various causes, primarily rooted in the obstruction of the appendix lumen. Factors contributing to this obstruction include fecal accumulation, lymphoid hyperplasia and, in...
01:14Assessing Body Temperature - Axilla
Step 1: Perform hand hygiene and put on clean gloves to maintain infection control and prevent cross-contamination.
Step 2: Prepare the patient by explaining the procedure to ensure understanding and cooperation. Ensure privacy, expose the axilla, and inform the patient that minimal movement is crucial for an accurate reading.
Step 3: Adjust the patient’s clothing to expose only the axilla. It minimizes...