This prospective cohort study followed 189 patients for 2-5 years after acute patellar dislocation. It compares epidemiology and recurrence risk between first-time dislocators and patients with prior patellofemoral instability history. The central question: who dislocates, who recurs, and what predicts future instability?
The first question to ask any patient with acute patellar dislocation is whether this has happened before. A prior history of patellofemoral subluxation or dislocation multiplies recurrence risk 6.6-fold and should shift your counseling threshold immediately.
First-time dislocators can be counseled that their recurrence risk is relatively modest at 17% over 2-5 years with conservative management. Patients with prior instability face nearly a coin-flip probability of further episodes (49%) — a conversation that meaningfully changes shared decision-making around surgical stabilization.
When you see a young adolescent female with patellar dislocation and a family history of instability or DDH risk factors, assess the contralateral knee. Both factors independently predict bilateral instability, implicating systemic dysplasia rather than isolated traumatic injury.
A counterintuitive pearl from this paper: do not rely on MRI retinacular injury severity to risk-stratify for recurrence. Less soft tissue damage on MRI correlates with higher recurrence risk, because dysplastic joints dislocate with less force and less tissue tearing.
This prospective cohort study followed 189 patients for 2-5 years after acute patellar dislocation. It compares epidemiology and recurrence risk between first-time dislocators and patients with prior patellofemoral instability history. The central question: who dislocates, who recurs, and what predicts future instability?
The first question to ask any patient with acute patellar dislocation is whether this has happened before. A prior history of patellofemoral subluxation or dislocation multiplies recurrence risk 6.6-fold and should shift your counseling threshold immediately.
First-time dislocators can be counseled that their recurrence risk is relatively modest at 17% over 2-5 years with conservative management. Patients with prior instability face nearly a coin-flip probability of further episodes (49%) — a conversation that meaningfully changes shared decision-making around surgical stabilization.
When you see a young adolescent female with patellar dislocation and a family history of instability or DDH risk factors, assess the contralateral knee. Both factors independently predict bilateral instability, implicating systemic dysplasia rather than isolated traumatic injury.
A counterintuitive pearl from this paper: do not rely on MRI retinacular injury severity to risk-stratify for recurrence. Less soft tissue damage on MRI correlates with higher recurrence risk, because dysplastic joints dislocate with less force and less tissue tearing.