Primary Acute Patellar Dislocation: A Comprehensive Narrative Review of Epidemiology, Risk Factors, Treatment Strategies, and Outcomes

Primary acute patellar dislocation (PAPD) is a common knee injury, particularly among adolescents and young adults, and is associated with variable risks of recurrent instability, osteochondral injury, and long-term patellofemoral degeneration. The aim of this narrative review was to summarize current evidence on the epidemiology, injury mechanisms, risk factors, diagnosis, emergency management, definitive treatment, complications, and prognosis of PAPD. A structured literature search was conducted in MEDLINE, Scopus, CINAHL, and Google Scholar from database inception to July 2025 using terms including patellar dislocation, acute patellar dislocation, primary patellar dislocation, first-time patellar dislocation, MPFL injury, risk factors, emergency management, treatment, and outcomes. Peer-reviewed studies, systematic reviews, meta-analyses, randomized trials, cohort studies, and clinical guidelines addressing acute first-time patellar dislocation were considered. Evidence was narratively synthesized across clinically relevant domains. Current literature supports a risk-stratified approach in which radiographs remain the first-line imaging modality after acute presentation or reduction, while MRI is useful for identifying osteochondral injuries, MPFL lesions, and anatomical risk factors. Conservative rehabilitation remains appropriate for low-risk first-time dislocations without major osteochondral injury or significant malalignment, whereas surgery may be considered in selected patients with displaced osteochondral fragments, loose bodies, persistent instability, or high-risk anatomy. Because available studies are heterogeneous and long-term evidence remains limited, further prospective research is required to refine patient selection and optimize treatment pathways.