The minimal clinically important difference for function and strength in patients undergoing reverse shoulder
Carlos Torrens1, Pau Guirro1, Fernando Santana1
1Department of Orthopedics, Hospital del Mar-Parc de Salut Mar, Barcelona, Spain.
Journal of Shoulder and Elbow Surgery
|October 1, 2015
Summary
Reverse shoulder arthroplasty (RSA) significantly improves shoulder function, but many patients do not achieve the minimal clinically important difference (MCID) in all areas. Patient perception varies, with small rotation gains being beneficial but large elevation gains needed for perceived improvement.
Area of Science:
- Orthopedic surgery
- Biomechanics
- Patient-reported outcomes
Background:
- Cuff-deficient shoulders often lead to significant functional limitations.
- Reverse shoulder arthroplasty (RSA) is a common surgical option for these conditions.
- Assessing patient-perceived functional improvement beyond statistical significance is crucial.
Purpose of the Study:
- To evaluate the functional outcomes and patient-perceived minimal clinically important difference (MCID) after RSA in cuff-deficient shoulders.
- To determine the proportion of patients achieving MCID across different functional domains.
Main Methods:
- Prospective longitudinal study of 60 patients undergoing RSA for cuff-deficient shoulders.
- Constant score and a 15-item anchor questionnaire were administered pre-operatively and at 1-year follow-up.
- MCID was determined for overall function, forward elevation, lateral rotation, internal rotation, and strength.
Main Results:
- The Constant score significantly improved post-RSA (30.1 to 58.4, P < .001).
- Statistically significant improvements were noted in forward elevation, lateral rotation, and strength, but not internal rotation (P = .15).
- MCID achievement varied: 46.7% for overall function, 20% for forward elevation, 50% for lateral rotation, 45.8% for internal rotation, and 33.3% for strength.
Conclusions:
- While RSA yields statistically significant functional improvements, a substantial number of patients do not reach MCID in function and strength.
- Patients perceive small gains in rotation favorably, but require substantial improvements in forward elevation to consider the outcome beneficial.
- Further research should explore factors influencing MCID achievement post-RSA.
