Heterotopic ossification following primary reverse total shoulder arthroplasty.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Limited data exists on heterotopic ossification (HO) following reverse total shoulder arthroplasty (rTSA).
• Understanding HO prevalence and its clinical impact is crucial for patient outcomes.

Purpose of the Study:

• To determine the occurrence of HO after primary rTSA.
• To evaluate the impact of HO on clinical outcomes and complications.

Main Methods:

• Retrospective analysis of a prospectively maintained rTSA database (2009-2018).
• Inclusion of primary rTSA cases with a minimum 2-year follow-up.
• HO classification (types 1a, 1b, 1c, 2) and assessment of clinical outcomes (CS, SSV, ROM), complications, and reinterventions.

Main Results:

• HO was observed in 59% of 663 rTSAs at 2-year follow-up, with type 1b (34%) being most common.
• HO showed minimal impact on Constant-Murley Score (CS) but significantly affected abduction (p=0.02) in type 1c.
• Risk factors for HO included female gender, moderate alcohol consumption, secondary fracture treatment, and osteoporosis; no association with complications or reinterventions.

Conclusions:

• HO is highly prevalent after rTSA and can progress over time.
• Certain factors like female gender and moderate alcohol intake correlate with higher HO rates.
• HO primarily affects abduction and overall clinical outcomes, particularly severe forms (type 1c), without linking to other complications.