<Tr> <Th> Specialty </Th> <Td> Emergency medicine </Td> </Tr> <P> The unhappy triad, also known as a blown knee among others, is an injury to the anterior cruciate ligament, medial collateral ligament, and medial meniscus . Analysis during the 1990s indicated that this' classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries . Some authors mistakenly believe that in this type of injury, acute tears of the medial meniscus always present with a concomitant lateral meniscus injury . However, the 1990 analysis showed that lateral meniscus tears are more common than medial meniscus tears in conjunction with sprains of the ACL . </P> <Ul> <Li> Pain in affected knee </Li> <Li> Stiffness and swelling in affected knee </Li> <Li> Catching or locking of the knee in affected knee </Li> <Li> Instability of the knee with twisting or side - to - side movements (The sensation of the knee "giving out"). </Li> <Li> Inability to move the knee through its full range of motion </Li> </Ul> <Li> Pain in affected knee </Li>

Which of the following is not part of the unhappy triad