Knee Algorithm

An interactive decision flowchart for knee complaints. It uses the Ottawa Knee Rule to decide whether imaging is warranted, then Lachman and the pivot shift for the anterior cruciate ligament, joint line tenderness and the Thessaly test at 20 degrees for meniscal injury, valgus and varus stress at 0 and 30 degrees for the collateral ligaments, patellar ballottement for effusion, and the moving patellar apprehension test. It separates knee fracture, anterior cruciate ligament injury, meniscal injury, medial or lateral collateral ligament injury, effusion with patellar instability, and serious structural pathology being unlikely.

Written for qualified clinicians. The tool supports clinical reasoning; it does not replace examination, imaging or diagnosis.