OTSR - 2026-05-04 - Journal Article
Diagnostic performance of the Francophone Arthroscopic Society (SFA) score for anterior cruciate ligament rupture and intra-articular knee lesions in the emergency department: a prospective multicenter study.
Bordes L, Stoclet T, Lalevée M, Kloek N, Taalba M, Curado J
Topics
Key Takeaway
The SFA score achieves 100% sensitivity and 100% NPV at a threshold ≤4 for ruling out ACL rupture in the emergency department, with an AUC of 0.759 for ACL injury and 0.82 for all severe intra-articular lesions.
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Summary
This prospective multicenter study assessed the external validity of the history-based SFA score for ACL rupture screening in 115 ED patients aged 18–55 presenting within 9 days of acute knee trauma without fracture. The SFA score ≤4 ruled out ACL rupture with 100% sensitivity and 100% NPV, while a score ≥8 predicted ACL tear with 77.6% specificity and 67.4% PPV. The score also demonstrated AUC 0.82 for identifying any severe intra-articular lesion, supporting its use as a triage and imaging-referral decision tool.
Key Limitation
The 23% loss to follow-up (35/150 patients) risks verification bias, as patients who did not complete follow-up may systematically differ in injury severity, threatening the validity of the reported sensitivity and NPV.
Original Abstract
BACKGROUND
The Francophone Arthroscopic Society (SFA) score was designed to identify patients with anterior cruciate ligament (ACL) rupture in the immediate post-traumatic period, based on history alone (pain intensity, immediate post-traumatic functional impairment, history of a "pop," feeling of instability, and knee swelling). The aim of this multicenter study was to assess the external validity of the SFA score for ACL injury screening in the emergency department and to evaluate its ability to predict other significant intra-articular knee lesions.
HYPOTHESIS
The SFA score is a reliable screening tool for ACL rupture in emergency departments and can also help identify patients at high risk of severe intra-articular knee injuries.
PATIENTS AND METHODS
This prospective multicenter observational study enrolled 150 consecutive patients aged 18-55 years who presented to the emergency department within 9 days after a knee trauma and had no fracture on standard radiographs. Patients were excluded if the trauma required immediate surgical management or if they had a history of trauma or surgery on the same knee. The SFA score was assessed by the emergency physician at first presentation. The reference diagnosis (ACL rupture, other intra-articular lesions or no lesion) was established at follow-up by an orthopedic surgeon, based on clinical examination or MRI.
RESULTS
Of the 150 included patients, 115 completed follow-up and were analyzed; 48 had an ACL rupture and 67 an intact ACL. For ACL injury screening, the SFA score showed an AUC of 0.759 (95% CI 0.673-0.845). A score ≤4 demonstrated a sensitivity of 100% and a NPV of 100% for ruling out ACL rupture, whereas a score ≥8 indicated a high probability of ACL tear (specificity 77.6%, PPV 67.4%). For severe intra-articular knee lesions as a whole, the AUC was 0.82 (95% CI: 0.745-0.895).
DISCUSSION
This study supported the external validity of the SFA score for screening ACL rupture and other significant intra-articular knee lesions in the emergency department setting. The score appears to be a useful decision-making tool to guide triage, imaging, and orthopedic referral in patients presenting with acute knee trauma.
LEVEL OF EVIDENCE
III; prospective observational multicenter study.