Arm lengthening after reverse shoulder arthroplasty: a review

Area of Science:

• Orthopedic Surgery
• Biomechanics
• Radiographic Assessment

Background:

• Reverse shoulder arthroplasty (RSA) can induce biomechanical changes.
• Assessing upper limb lengthening post-RSA is vital for functional outcomes.
• Soft tissue tension requires careful consideration to balance function and complications.

Purpose of the Study:

• To understand biomechanical changes from RSA.
• To review radiographic assessment techniques for upper limb lengthening.
• To determine optimal soft tissue tension for functional outcomes and complication avoidance.

Main Methods:

• Systematic review of seven English, French, or German articles.
• Inclusion criteria focused on upper extremity lengthening measurement, complications, and postoperative function.
• Articles provided evidence levels I-IV relevant to search terms.

Main Results:

• Humeral length changes ranged from -5 to 5 mm; upper extremity length changes were 15-27 mm.
• Average acromiohumeral distance was 23 mm.
• Humeral/arm shortening increased dislocation risk and impaired active elevation; subclinical neurological lesions were common.

Conclusions:

• Deltoid tensioning via humeral length restoration and increased acromiohumeral distance is key for function and preventing dislocation.
• Excessive arm lengthening must be avoided.
• 0-2 cm of lengthening is a safe target to prevent postoperative neurological impairment.