Poster 161: Rotator Cuff Repair and Minimum Clinically Important Difference: Does Number of Tendons Involved Affect the Minimum Clinically Important Difference Value?
Authors: Doxey Stephen , Kleinsmith Rebekah , Wegner Mariah , Schweitzer Adam , Hadro Adam , Aadalen Kirk , Nelson Bradley , Cunningham Brian 
Published: August 2024

Objectives: The minimum clinically important difference (MCID) is a commonly used measure to aid in determining significant improvements for patient-reported outcomes (PROs). As MCID and PROs continue to be implemented in shoulder procedures, MCID can greatly differ depending upon the specific patient population, follow-up time, and methodology. In the setting of rotator cuff repair (RCR), there are few studies that discuss the effect of tendon involvement on MCID achievement. Other orthopaedic conditions have calculated separate MCIDs depending on the severity of the fracture or pathology. The purpose of this study was to calculate an MCID for one-, two-, and three-tendon RCR. They hypothesis was that MICD values would be lower for larger repairs compared to smaller repairs. The primary outcome was the American Shoulder and Elbow Surgeons (ASES) score. Secondary outcomes included evaluating what patient and surgical characteristics affect MCID achievement for each MCID. Methods: A prospectively collected PRO database was queried for patients who underwent primary RCR from 2018 to 2022. Revision procedures, patients with a history of prior shoulder surgery, or patients lacking PROs at any time point were excluded. Demographic and surgery characteristics were extracted through chart review. The primary outcome was the ASES score. ASES is a validated instrument scored on a 100-point scale with 0 indicating the” worst outcome” and 100 being the “best outcome.” MCID was calculated using the anchor-based method as has been done in previous works. The anchor question from PROMIS-10 asks, “In general, how would you rate your physical health?” scored on a 5-point Likert scale. An increase of one point was deemed to be a significant improvement in the anchor to calculate the MCID. An MCID was calculated for the three sizes of RCRs in this sample. Statistical analysis included descriptive statistics, as well as independent sample t-tests, chi-square tests, and fisher exact tests. Results: A total of 799 patients met inclusion criteria. Most patients were male (n=474, 59.3%) and were 61.2 years old. There were 61.5% of patients who had their dominant shoulder treated with RCR. Patients typically presented with at least one tendon that had a full thickness tear (n=643, 80.5%). Many underwent various concomitant procedures including subacromial decompression (83.9%), biceps tendon procedures (tenotomy or tenodesis) (59.0%), distal clavicle excision (24.2%), and arthroscopic debridement (24.0%). The average case length was 130.1 minutes. There were 36 symptomatic retears (4.5%), 10 revisions (1.3%), and 14 other reoperations (1.8%) within one year. ASES scores at baseline and one-year were 48.1 and 84.6, respectively, with an average one-year change of +36.6. MCIDs by number of tendons involved were 40.5, 36.3, and 39.3 for single-, two-, and three-tendon repairs. The number of patients that achieved MCID by tendon size did not statistically differ between groups (Single: 51.0%; Two: 53.0%; Three: 50.0%, p>0.610, respectively). MCID achievement and biceps tendon procedures trended towards significance for the single-tendon cohort (p=0.085), while patient sex trended towards significance in the two-tendon cohort (p=0.055). More acute tears compared to chronic tears met MCID in the three-tendon cohort although this only trended towards significance (p=0.074). MCID achievement was affected by symptomatic retears in the two-tendon RCR group (p<0.001). While reoperation trended towards significance in the single-tendon RCR group (p=0.058). Conclusions: This study found that MCID value varied by the number of tendons involved in RCR, with two-tendon repairs having the lowest MCID (36.3). The number of patients that met MCID in each cohort was similar. Single-tendon tears appear to be more affected by biceps tendon procedures and reoperations, although both of these findings only trended towards significance. Patients with two-tendon tears were shown to be affected by symptomatic retear (p<0.001), and patient sex, although the later finding was not statistically significant (p=0.055). MCID achievement in three-tendon RCRs appear to be influenced by tear chronicity with those with an acute tear being more likely to attain MCID, although this finding was not significant (p=0.074). Surgeons should consider the size of a cuff repair and what corresponding surgical and patient factors may be more pertinent to each patient to help maximize patient outcomes.