The minimal clinically important differences of the Simple Shoulder Test are different for different arthroplasty...

Area of Science:

• Orthopedic surgery
• Patient-reported outcomes
• Clinical trial methodology

Background:

• Patient self-reported measures are crucial for evaluating shoulder arthroplasty effectiveness.
• The Minimal Clinically Important Difference (MCID) quantifies patient-important improvement but may vary by arthroplasty type.
• Understanding diagnosis and surgical approach is key to interpreting patient outcomes.

Purpose of the Study:

• To determine the MCID for the Simple Shoulder Test (SST) across five distinct shoulder arthroplasty types.
• To establish the MCID for the percentage of maximal possible improvement (%MPI) for each arthroplasty type.
• To provide specific MCID thresholds for assessing the effectiveness of different shoulder arthroplasty procedures.

Main Methods:

• Included 887 patients with pre- and 2-year postoperative Simple Shoulder Test (SST) scores and satisfaction data.
• Analyzed five arthroplasty types: anatomic total shoulder arthroplasty (aTSA), ream-and-run (R&R), reverse total shoulder arthroplasty (rTSA), cuff tear arthropathy arthroplasty, and hemiarthroplasty.
• Utilized an anchor-based method to calculate MCID for both absolute SST scores and %MPI for each group.

Main Results:

• All arthroplasty types showed significant SST improvements.
• Overall MCID for SST change was 2.3, ranging from 1.6 (aTSA) to 3.7 (rTSA).
• Overall MCID for %MPI was 32%, ranging from 22% (aTSA) to 42% (hemiarthroplasty).
• Patient success rates (exceeding MCID) were highest for aTSA (96%) and lowest for hemiarthroplasty (61%).

Conclusions:

• A single MCID value is likely inappropriate for all shoulder arthroplasty types.
• This study provides specific MCID thresholds for evaluating the effectiveness of common shoulder arthroplasty procedures.
• These findings aid in more accurate interpretation of patient-reported outcomes following shoulder replacement surgery.