Heterotopic ossification in primary total hip arthroplasty: risk factor analysis

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering

Background:

• Heterotopic ossification (HO) is a potential complication following total hip arthroplasty (THA).
• Identifying independent risk factors for HO is crucial for effective prevention strategies.

Purpose of the Study:

• To investigate age, sex, surgical approach, surgical duration, and drainage removal time as independent risk factors for HO after THA.
• To determine which patient and surgical characteristics predict severe HO development.

Main Methods:

• Retrospective analysis of 1225 patients undergoing THA via posterolateral approach over 15 years.
• Exclusion criteria included lack of X-ray follow-up or HO prophylaxis.
• HO severity was classified using Brooker criteria, with severe HO defined as grade 2 or higher. Multivariable analysis was used to assess risk factors.

Main Results:

• A high incidence of HO (67.6%) was observed.
• Severe HO rates were significantly higher in men (44.1%) versus women (29.1%), patients over 65 (39.9%) versus younger patients (30.3%), longer surgical times (>90 min) (35.7%) versus shorter times (29.1%), and delayed drainage removal (36.2%) versus early removal (24.8%).
• Minimally invasive approach showed a trend toward lower severe HO rates (27.1%) compared to standard approach (32.8%), though not statistically significant (p=0.067).

Conclusions:

• Male sex, age over 65, surgical duration exceeding 90 minutes, and delayed postoperative drainage removal are significant risk factors for severe heterotopic ossification after THA.
• These identified risk factors can help stratify patients for targeted heterotopic ossification prophylaxis.