Next, I'll introduce Dr. Jillian Cain from the University of Pittsburgh, and she'll be discussing clinical outcomes may not be influenced by kinematic changes after superior capsular reconstruction. Thank you. Hello, my name is Jillian Cain. I'm a medical student at the University of Pittsburgh School of Medicine. I'm presenting research that I've been involved in over the past three to four years. I'd like to begin by acknowledging the contributions of my co-authors. These are our disclosures. Superior capsule reconstruction, also known as SCR, is emerging as a viable treatment for irreparable rotator cuff tears. SCR uses autograft or allograft to stabilize the humeral head within the glenoid, helping to prevent superior migration of the humerus, measured by a chromiohumeral distance. The graft is laid flat and attached to the superior portion of the glenoid and the greater tuberosity of the humerus. SCR is often utilized for patients with minimal rotator cuff arthropathy and has been shown to restore stability of the glenoid humeral joint in cadavers, but its effectiveness at controlling humeral motion in vivo is unknown. Reported changes in acromiohumeral distance following SCR are inconsistent, with some studies reporting an increase of 2.6 to 3.2 millimeters, while other studies reporting no significant change. The aim of this study is to determine the effect of SCR on static and dynamic acromiohumeral distance, shoulder function, and patient-reported outcomes. We hypothesize that after SCR, static and dynamic acromiohumeral distance would increase, humeral head location on the glenoid would be more inferior post-SCR, and changes in acromiohumeral distance for humeral head translation would correlate with increased glenohumeral abduction range of motion and improved patient-reported outcomes. This study includes 10 patients who have returned for one-year postoperative testing. Kinematic testing was done before surgery and one year after receiving superior capsule reconstruction. We imaged the affected shoulder during three trials of scapular abduction. At each visit, synchronized biplane radiographs were collected at 50 images per second for two seconds. We then determined shoulder joint motion using a validated registration process that matched 3D models of the bones to synchronized biplane radiographs with submillimeter accuracy. Finally, shoulder joint motion was visualized and kinematics were measured in three dimensions as shown here. From this data, we focus on measuring acromiohumeral distance, which is defined as the minimum distance between the acromion and the humeral head. This was calculated at every five degrees of glenohumeral abduction and averaged across trials and then across subjects. Additionally, humeral head translation relative to glenoid was normalized to glenoid size and interpolated to every 10 degrees of glenohumeral abduction and averaged across trials at corresponding abduction angles. Lastly, patient-reported outcomes were collected before and one year after surgery. The differences in pre- and post-SER stats were run with a Wilcoxon sign-rank test. This figure depicts static and dynamic acromiohumeral distance pre- and one-year post-SER. Blue bars correspond to acromiohumeral distance pre- and red bars correspond to acromiohumeral distance one-year post. Air bars represent plus or minus one standard deviation. No difference was detected in static acromiohumeral distance from pre- to one-year post. The average dynamic acromiohumeral distance during glenohumeral abduction decreased a small but significant amount from pre- to one-year post. However, we were unable to detect any changes in acromiohumeral distance at any 10-degree increment of glenohumeral abduction from pre- to one-year post. This figure shows the average humeral head location during the abduction motion. Blue corresponds to location pre-SER and red corresponds to location one-year post. The black cross indicates the center of the glenoid. Air bars represent plus or minus one standard deviation. The humeral head position during abduction was more superior one-year post compared to pre. The average AP position of the humeral head during abduction remained unchanged from pre- to one-year post. The only pre- to one-year post difference in humeral head location at corresponding 10-degree increments of glenohumeral abduction occurred at 90 degrees, where the humeral head was more superior from pre- to one-year post. These are our patient-reported outcomes. Green cells indicate a survey score that improved beyond the minimum clinically important difference from the pre-surgical data. All post-operative data for ASES work and DASH surveys were improved beyond the MCID and were found to be clinically significant. The only association between changes in kinematics and changes in patient-reported outcomes was a correlation between a larger posterior shift in humeral head position and improved ASES scores from pre- to one-year post. Contrary to previous cadaver research, we failed to find a significant change in static acromi-humeral distance from pre- to post-surgery. The dynamic distance was less than the static, which suggests that a static acromi-humeral distance may not be the best representation of acromi-humeral distance during dynamic motions. Additionally, we observed small changes in superior-inferior humeral head position following superior capsule reconstruction. However, these changes were minimal with little impact on patient-reported outcomes from pre- to post-surgery. And finally, we identified one correlation between kinematics and patient-reported outcomes. However, all patient-reported outcomes improved beyond the MCID. To conclude, we did not observe any kinematic difference in acromi-humeral distance or contact path following SCR. Despite the lack of kinematic associations, excellent outcomes were achieved in all patients. This suggests that changes in joint mechanics between the humerus and glenoid may not be the primary driver for improved clinical outcomes after SCR. Thank you for your time.

clinical outcomes

superior capsular reconstruction

irreparable rotator cuff tears

acromiohumeral distance

shoulder function