Partial anterior cruciate ligament (ACL) ruptures are common. The ability to distinguish between various types of ACL ruptures preoperatively would allow surgeons to choose the most appropriate surgical treatment.

A partial ACL rupture can be diagnosed preoperatively.

The goal of this single-center, prospective study was to establish correlations between various macroscopic types of ACL ruptures determined by arthroscopy with data from clinical examination, knee laxity measurements (GnRB^®) and magnetic resonance imaging (MRI). The 49 patients included over a six-month period had a diagnosis of ACL rupture based on the clinical examination. Four arthroscopy categories were defined based on the French Arthroscopy Society (SFA) classification. Each patient had their knee laxity measured, a preoperative MRI performed and a clinical exam done in the operating room before the procedure.

During arthroscopy, the ACL was described as “Complete tear” in 23 of 49 patients, “Healed onto PCL” in 12, “Posterolateral bundle preserved” in 14 and “Healed into notch” in none of the patients. The clinical exam alone could not discriminate between the various types of ruptures (P>0.05). With MRI, the sensitivity was 84% and the specificity was 92% for partial ACL rupture. There was a strong correlation between MRI and the various arthroscopy groups (P<0.05). There was a significant difference (P<0.05) between partial and complete ruptures in terms of knee laxity.

This study helped define the relationships between arthroscopy findings, MRI findings and knee laxity measurements. It is feasible to make a preoperative diagnosis of partial ACL rupture.

Level IV, prospective cohort study.