Subacromial notching after reverse total shoulder arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Subacromial notching (SaN) is a newly identified complication following reverse total shoulder arthroplasty (RTSA).
• SaN involves subacromial erosion due to impingement, distinct from scapular notching.
• This study investigates the clinical incidence and contributing factors of SaN.

Purpose of the Study:

• To identify risk factors associated with subacromial notching (SaN) after RTSA.
• To evaluate the impact of SaN on functional outcomes and patient pain levels.
• To establish clinical guidelines for preventing SaN by considering patient anatomy.

Main Methods:

• Retrospective review of 125 RTSA patients with at least 2 years follow-up.
• Radiographic analysis of preoperative and postoperative X-rays to assess anatomical parameters and implant positioning.
• Evaluation of pain (VAS) and functional scores (ASESS) to determine SaN's clinical effect.

Main Results:

• SaN occurred in 12.8% of patients.
• Preoperative center of rotation-acromion distance (<14.0 mm) and postoperative humerus lateralization (<19.0 mm) were significant risk factors.
• Patients with SaN reported worse pain and ASESS scores postoperatively.

Conclusions:

• Subacromial notching (SaN) negatively impacts clinical outcomes after RTSA.
• Patient's native anatomy and surgical lateralization degree are key factors in SaN development.
• Tailoring implant lateralization to individual anatomy is crucial for mitigating SaN risk.