Terrible Triad
O’Donoghue’s Triad, also known as Terrible Triad, refers to a knee injury involving multiple ligaments and
cartilage within the knee. The medial collateral ligament (MCL), anterior cruciate ligament (ACL), posterior
cruciate (PCL), and medial and/or lateral meniscus (cartilage) all sustain damage. This injury is most often
sustained when a lateral (from the outside) force impacts the knee while the foot is fixed on the ground. This
type of injury occurs often in contact sports such as football or motocross.
In about 10% of cases the force is applied to the opposite side of the knee, and the lateral and posterolateral
ligaments are torn. This constellation of injuries does not have a famous doctor's name associated with it, and
the treatment of this will also be discussed below.
When making treatment decisions, it’s important to remember that every ligament has its own healing potential,
In the 1980s it was though best to immediately repair or reconstruct all the injured structures on the emergency
basis. This typically led to a prolonged post operative course, disabling stiffness, and several subsequent operations
to resolve the stiffness. It was usually a career ending injury.
Rather than embarking on such uncertain treatments, we have found it most efficactious to not interfere with the
natural healing postential of those ligaments that can heal on thier own. Furthermore, many, but not all, meniscal
cartlage tears will also heal without surgical intervention. The MCL, PCL, and many meniscal tears can be treated
in this way. We place a cylinder cast on the leg, that allows patients to walk without crutches and do straight leg
raising exercises for two weeks. After two weeks, the cast gets loose, and we remove it, do some range of motion
exercises, and place a new one for another two weeks. After that we remove the cast and find that these ligaments
are healed.
Now, we have resloved a catastrophic three ligament injury to a single one ligament (ACL) injury, and we can proceed
with the exercise program designed to prepare the knee for ACL surgery. Typically this lasts about four weeks, and then
standard ACL surgery, sometimes with repair of a meniscal cartlage when necessary, can be performed. A return to sports
three months later can be expected. All told, this "career ender" can be fully rehabed and back to sports in five months.
Injuries which involved the lateral and the posterolateral ligaments constitute 10% of multiple knee ligament injuries.
This ligament requires an early repair, best done in two weeks. Fortunately stiffness, is not a big problem with lateral
sided inuries. The meniscal cartlages are not usually torn, the posterior cruciate ligament (PCL) is allowed to heal on
its own, the lateral ligments are directly repaired, the ACL is reconstructed in the usual way with a living graft from
the opposite patella tendon, and a rehab program nearly identical to our standard ACL program is instituted, with expected
return to sports between three and four months.
