Genetics, sex and the use of platelet-rich plasma influence the development of arthrofibrosis after anterior cruciate ligament reconstruction.

Purpose: To identify genes and patient factors that are related to the development of arthrofibrosis in patients after anterior cruciate ligament (ACL) reconstruction and to develop a prognostic model. Methods: The study included patients diagnosed with ACL injury who underwent ACL reconstruction. Patients were enroled consecutively and divided into non-fibrotic (controls) and fibrotic (cases) groups until a balanced sample of matched case-control was achieved. Arthrofibrosis was considered pathological if the range of motion achieved 3 months after surgery decreased by at least 25% compared to its initial full range of motion. Patient variables and saliva samples were collected from each patient to perform a genetic approach by screening a set of candidate genes implicated in arthrofibrosis. Chi-squared was used to analyze the association between the development of arthrofibrosis and different independent variables. Binary logistic regression was used to develop a prognostic algorithm. Results: A total of 45 controls (non-fibrotic patients) (50.1%) and 44 cases (fibrotic patients) (49.9%) were included for analysis. The median age was 34.0 years (95% confidence interval = 29.0-38.0) and the number of women was 32 (35.9%). Seven genetic polymorphisms showed significant association with the development of arthrofibrosis ( Conclusion: Genetic alterations involved in inflammation and extracellular matrix turnover predispose to the development of arthrofibrosis after ACL reconstruction. Female sex was a risk factor in the development of this condition, while the application of PRP provided a preventive effect. The combination of patient and genetic variants of a patient allows the development of a prognostic algorithm for the risk of post-surgical arthrofibrosis. Level of Evidence: level III.