Background: Pathological medial plica is known to cause anteromedial knee pain. However, clinical diagnosis of pathological medial plica is poorly defined in the literature and therefore, arthroscopic diagnosis remains gold standard. We report a system of clinical diagnosis based on the criteria set by us for these painful conditions of the knee.

Methods: We prospectively studied forty-eight symptomatic patients (sixty-six knees) with clinical suspicion of pathological medial plica based on five “essential” and four “desirable” criteria set by us. All patients were subjected to arthroscopic examination, to confirm or disprove our clinical diagnosis and, for treatment.

Results: Arthroscopic examination confirmed our clinical diagnosis of medial plicae in forty-four (sixty-two knees) of these patients showing a diagnostic accuracy of 91.7% (95% confidence interval: 80.0%, 97.7%), sensitivity of 100% (95% CI: 92.0%, 100.0%) with our method. Those with pathological medial plicae at arthroscopy (forty-four patients; sixty-two knees), were treated by arthroscopic resection. Thirty-nine patients (fifty-five knees) showed satisfactory outcome (95% CI: 75.4%, 96.2%) after arthroscopy.

Conclusions: We believe that our method of clinical diagnosis of pathological medial plica is simple, non-invasive, economic and reliable. Symptomatic medial plica can be successfully treated by arthroscopy. This study has changed our clinical practice and also allowed us to decrease substantially the cost of diagnostic imaging.