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.

A MRI is usually ordered to be certain that the tear of the MCL is not at its lower end.  Rarely is it, and if so a limited l surgical procedure is necessary to repair it back to the bone.  Having said that, in the vast majority of cases, we have found it most efficacious to not interfere with the natural healing potential of those ligaments that can heal on their own. Furthermore, many, but not all, meniscal cartilage 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 or a locked brace on the leg that allows patients to walk without crutches and do straight leg raising exercises for two weeks. After two weeks, a cast gets loose, and we remove it, do some range of motion exercises and place a new one for another two weeks.  When a brace is used, it is removed, some range of motion exercises performed, and it is replaced, tightening the Velcro.  After that we remove the cast or brace and find that these ligaments are healed.

Now, we have resolved 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 cartilage when necessary, can be performed.  Uncommonly, the MCL has not healed, and it is reconstructed with an allograft.  Repairing the meniscus or reconstructing the MCL does not lead to any change in the rehabilitation process.   A return to sports three months later can be expected. All told, this “career ender” can be fully rehabbed and back to sports within six 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 injuries. The meniscal cartilages are not usually torn, the posterior cruciate ligament (PCL) is allowed to heal on its own, the lateral ligaments 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 in four months.