Gregory P. Nicholson
BOSTON — According to a presenter at the American Orthopaedic Society for Sports Medicine Annual Meeting, time had a significant impact on rotator cuff tear size progression from preoperative MRI-measured dimensions to dimensions taken at the time of repair.
“As orthopedic surgeons, we can have confidence that rotator cuff tear size will correlate with your MRI findings with a certain time frame,” Gregory P. Nicholson, MD, said during his presentation. “But as time elapses between preoperative MRI and rotator cuff repair, the MRI is going to underestimate the true size of the tear, especially in the anterior-posterior dimension you seen in arthroscopy. On that anterior-posterior dimension, within 3 to 9 months, there was about a 2.4-cm to 2.5-cm difference. But as we got beyond 9 months, that difference got bigger. Now, you are greater to almost [a] 0.5-cm increase.”
Nicholson and colleagues obtained MRIs for 64 patients who underwent rotator cuff repair. Investigators recorded the location, area of the tear and anterior band, and noted the supraspinatus status. Average time between preoperative MRI and rotator cuff repair was 107.3 days. Two sample t-tests were used to determine the temporal effect on tear size from the MRI date to the surgery date and if there were any changes observed. Patients were put into the following time cohort groups based on time between preoperative MRI to rotator cuff repair: 1 month or less; 1 month; 1 month to 2 months; 2 to 3 months; 3 to 9 months; and 9 months or more. For each cohort, the delta or difference between intraoperative and preoperative MRI measurements was calculated.
Results from the t-tests showed a significant time effect on the size of the tear between the preoperative MRI and intraoperative measures. Nicholson noted this was significant for the anterior-posterior dimension, the medial-lateral dimension and total area of the tear. Additional analysis was performed to determine the critical time interval for tear progression in which there was a correlation between MRI and tear size. As time increased, the delta increased, as shown by the change in anterior-posterior dimension between the MRI and rotator cuff repair findings. Patients in the 2- to 3-month group had a positive mean delta in the anterior-posterior dimension. Greater differences in the positive mean delta were seen in the 3- to 9-month group and the 9 months or more group. The medial-lateral dimension showed similar trends in the mean delta values among the different time-interval cohorts. – by Monica Jaramillo
Naylor AJ, et al. Abstract 31. Presented at: American Orthopaedic Society for Sports Medicine Annual Meeting; July 11-14, 2019; Boston.
Disclosures: Nicholson reports he is a board or committee member of the American Shoulder and Elbow Surgeons; is a paid presenter or speaker for Arthrosurface; receives intellectual property (IP) royalties from Innomed; is a paid consultant for Tornier; and receives IP royalties and is a paid consultant for Wright Medical Technology Inc.