Maximizing Muscle Function in Cuff-Deficient Shoulders: A Rehabilitation Proposal for Reverse Arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomechanics
• Rehabilitation Medicine

Background:

• Reverse shoulder arthroplasty (RSA) is a reconstructive procedure for severe shoulder joint dysfunction.
• Altered joint biomechanics are inherent to RSA, particularly in cuff-deficient shoulders.
• Effective rehabilitation is crucial for optimizing functional recovery post-RSA.

Purpose of the Study:

• To elucidate the biomechanical alterations in reverse shoulder arthroplasty.
• To propose a targeted rehabilitation protocol for cuff-deficient glenohumeral joints.
• To synthesize current evidence guiding post-operative rehabilitation strategies.

Main Methods:

• Review of current literature on shoulder biomechanics and RSA.
• Analysis of muscle activation patterns during shoulder movements.
• Development of a rehabilitation protocol based on evidence and biomechanical principles.

Main Results:

• Scapular plane abduction effectively activates key shoulder muscles, including the deltoid, teres minor, upper trapezius, and serratus anterior.
• External rotation recovery may be limited due to the absence of rotator cuff muscles and altered deltoid mechanics.
• An intact teres minor can contribute to external rotation in elevated positions.

Conclusions:

• Enhancing deltoid muscle efficiency pre- and post-RSA is paramount for successful rehabilitation.
• Exercises performed in the scapular plane and at higher abduction angles optimize muscle activation.
• This approach leads to improved functional outcomes in patients with cuff-deficient shoulders undergoing RSA.