Condition |
Mechanism of injury |
Clinical Features |
Comments |
Anterior
pain |
ACL injury |
Twisting or hyperextension |
Sudden pain and giving way |
Often accompanied by MCL and/or meniscal injury |
Unable to ambulate |
Hemarthrosis |
Abnormal anterior drawer, Lachman, or pivot shift test |
Inability to fully squat or duck waddle |
Rupture of patellar
or quadriceps tendon |
Fall on partially flexed knee |
Instability with ambulation |
May be associated with patellar fracture |
Significant pain and swelling |
Large effusion |
Posterior pain |
PCL injury |
Direct force to anterior knee with the knee in flexion,
fall onto flexed knee with foot in plantar flexion; hyperflexion;
hyperextension (after rupture of ACL) |
Effusion within 24 hours |
Usually combined with other injuries |
Limited range of motion |
Instability |
Tibia in posterior position relative to femur |
Medial pain |
MCL injury |
Valgus force without rotation |
Localized pain, ecchymosis, swelling and stiffness |
Often accompanied by ACL injuries (in which case knee
dislocation must be considered) |
Pain along course of ligament |
Laxity with valgus stress in 30 degrees of knee flexion |
Laxity with valgus stress in 0 degrees of knee flexion
indicates concurrent ACL injury |
Medial meniscal tear |
Twisting injury |
Usually able to ambulate, but weight bearing is limited
by pain |
|
Knee swelling and stiffness develop over 2 to 3 days |
Mechanical symptoms |
Medial pain with twisting or squatting |
Medial joint line tenderness |
Positive McMurray test |
Positive bounce home test |
Decreased range of motion |