2025 ISAKOS Biennial Congress ePoster
Systematic Review Of Shoulder Imaging Abnormalities In Asymptomatic Adult Shoulders (Scrutiny): Abnormalities Of The Acromioclavicular Joint And Subacromial Space
Thomas Ibounig, MD, Helsinki FINLAND
Lasse Rämö, MD, PhD, Helsinki FINLAND
Romi Haas, MD, PhD,, Melbourne AUSTRALIA
Teppo Jarvinen, MD, PhD, Tampere FINLAND
Sean Docking, Md, PhD,, Melbourne AUSTRALIA
Sharon Sanders, MD, PhD, Robina AUSTRALIA
Rachelle Buchbinder, MD, PhD, Prof., Melbourne AUSTRALIA
Helsinki University Hospital, Helsinki, FINLAND
FDA Status Not Applicable
Summary
Imaging abnormalities of the acromioclavicular joint and subacromial space are common in asymptomatic shoulders. In athlete populations, these abnormalities appear to be more prevalent and/or appear at a younger age compared to non-athlete populations of the same age.
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Abstract
Objective
To determine the prevalence of acromioclavicular joint and subacromial space imaging abnormalities in asymptomatic adults. Secondary objectives included comparing a) the prevalence between athletes and non-athletes, and b) the prevalence of imaging abnormalities in adults with and without symptoms from the same or comparable study populations.
Method
We conducted a systematic review of studies examining the prevalence of shoulder imaging abnormalities detected by X-ray, ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in asymptomatic adults (PROSPERO registration number CRD42018090041). This report focuses on imaging abnormalities of the acromioclavicular joint and the subacromial space. We searched Ovid MEDLINE, Embase, CINAHL and Web of Science from inception to June 2023. Our primary analysis was conducted on data from population-based studies, and we assessed the risk of bias and certainty of evidence using tools tailored for prognostic studies.
Results
Thirty-one studies (4 X-ray, 11 US, 15 MRI, 1 X-ray and MRI) reported useable prevalence data. One study was population-based (20 shoulders), 16 included miscellaneous study populations (2436 shoulders) and 14 included athletes (708 shoulders). The certainty of evidence was very low mainly due to high risk of bias, imprecision, and indirectness of the included studies. Clinical diversity precluded pooling. The population prevalence of acromioclavicular joint abnormalities ranged from 85% based on MRI findings to 95% based on X-ray findings. Prevalence of subacromial bursa abnormalities was reported as 90% (MRI), subacromial space abnormalities as 20% (X-ray), and subacromial calcification as 5% (X-ray).
Conclusion
The population-based prevalence of acromioclavicular joint and subacromial space abnormalities in asymptomatic shoulders is very uncertain, but structural changes were frequently observed in asymptomatic shoulders in both athletes and other study populations. In athlete populations, these abnormalities appear to be more prevalent and/or appear at a younger age compared to non-athlete populations of the same age. The prevalence of AC joint and SA space abnormalities was nearly as high in asymptomatic shoulders as in symptomatic shoulders