A predictive model of shoulder instability after a first-time anterior shoulder dislocation

Area of Science:

• Orthopedic surgery
• Medical decision-making
• Predictive modeling in healthcare

Background:

• First-time anterior shoulder dislocation (FTASD) management involves critical clinical and policy decisions.
• Predictive disease modeling enhances information for treatment discussions.
• A general-purpose, publicly available model is presented for FTASD management.

Purpose of the Study:

• To describe a publicly available disease model for FTASD.
• To illustrate its utility in managing FTASD.
• To improve shared decision-making through accurate prognostic information.

Main Methods:

• A Markov decision model was developed for FTASD natural history.
• Outcome probabilities were derived from literature and expert opinion.
• Model validation included internal and external assessments against existing cohorts.

Main Results:

• The model demonstrated effective external validation against Swedish and military cohorts.
• It provides detailed individual outcome predictions, such as a 77% risk of dislocation in year 1 for an 18-year-old male.
• Specific outcomes include the Western Ontario Shoulder Instability (WOSI) index and probabilities of recurrent instability or stable shoulder at 10 years.

Conclusions:

• Accurate prognostic information is crucial for FTASD management.
• Disease modeling effectively supports shared decision-making.
• The validated, publicly available model enables physicians to predict outcomes based on patient and treatment factors.