CHICAGO — Results presented at the American Shoulder and Elbow Surgeons Annual Meeting showed glenoid bone loss of 6.8% after a first-time anterior instability event and loss of 22.8%, with a high prevalence of bony Bankart lesions, in cases of recurrent instability.
Jonathan F. Dickens, MD, and colleagues prospectively followed 714 athletes for 4 years to identify those with shoulder instability. Researchers assessed subjective history of shoulder instability at baseline and obtained bilateral non-contrast shoulder MRIs in all participants with and those without a history of previous shoulder instability. Researchers also compared screening MRI with a post-injury MRI, measured glenoid width for each patient’s pre- and post-injury MRI and calculated the projected total glenoid bone loss, which was compared for patients with prior history of shoulder instability.
“There were 72 subjects that had an instability event, of which 21 shoulders had pre- and post-MRI imaging instability with isolated interior instability,” Dickens said in his presentation here. “There were 23 first-time instability events, six recurrent instability events and our first-time instability events baseline screening examination showed no history of anterior or posterior instability.”
Dickens noted three of six patients in the recurrent instability group had persistent symptoms of instability. He added results showed one index dislocation and five subluxation events among the six patients with recurrent instability, as well as five index dislocations and 18 index subluxations among the 23 patients with first-time instability.
“Median time from screening MRI to injury was 311 days and from injury to post-injury MRI was 50 days,” Dickens said.
Patients in the first-time instability group had a change in glenoid width of 6.8% vs. 13.6% in the recurrent instability group, according to Dickens. Dickens noted bone loss less than 5% and greater than 5% occurred in 48% and 52% of patients in the first-time instability group, respectively.
“In the recurrent instability group, five of the six shoulders had a bony Bankart lesion with a change in glenoid width of 13.6% and 22% change in glenoid width when compared to its expected glenoid width,” Dickens said. – by Casey Tingle
Dickens JF, et al. Paper 1. Presented at: American Shoulder and Elbow Surgeons Annual Meeting; Oct. 12-14, 2018; Chicago.
Disclosure: Dickens reports he is a board or committee member for the American Academy of Orthopaedic Surgeons, the American Orthopaedic Society for Sports Medicine, the Arthroscopy Association of North America and the Society of Military Orthopaedic Surgeons.