Multiple Knee Ligament Injury

There are four main ligaments that stabilize the knee that contain or restrain motion between the thigh bone and leg bone: the anterior cruciate ligament, the posterior cruciate ligament, the medial collateral ligament, and the lateral collateral ligament. They perform the important function of maintaining knee stability for walking, pivoting, turning, and almost any athletic activity.

A number of combined knee ligament injury patterns have occurred such as: 1) anterior cruciate ligament and posterior cruciate ligament tear with tears of the posterolateral corner, and 2) anterior cruciate ligament and posterior cruciate ligament tear with tear of the medial collateral ligament.


Most knee ligament injuries involve a single ligament injury, such as an isolated anterior cruciate ligament, medial collateral ligament, or posterior cruciate ligament tear. When there is major trauma, such as a direct blow to the knee, a fall from a height, or a motor vehicle trauma, several knee ligaments can be torn at the same time. It requires immediate attention, and patients will have various immediate treatment such as an arterial graft and external fixator applied to hold the knee in place while these other injuries heal.


Typical symptoms include:

  • Severe instability and disability that adversely affects everyday life, work, and sports participation.
  • A dislocated knee.
  • Nerve injury at the level of the knee.
  • Severe artery injury.


The treatment of these very severe knee ligament injuries almost universally requires surgery. Rarely, in the most sedentary and low demand patients, bracing and rehabilitation will diminish the instability complaints. For most other patients, a very involved surgical reconstruction is required. Because surgical correction involves the reconstruction of several ligaments, the surgeon often will utilize grafts or tendon tissue from cadavers or human donors.

The surgical reconstruction takes a dedicated team and is a very technically demanding procedure. This type of surgery is best performed by surgeons with experience with these procedures and one that performs a number of these procedures on an annual basis. The surgeon will use the arthroscope, a small instrument that is inserted into the knee that is connected to a camera and monitor. Often, several of the ligaments will require reconstruction to include the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and collateral ligaments

The surgeon will use the arthroscope to create tunnels in the thigh and tibia bone with a small drill that will permit the grafts to be placed into the knee and re-create the torn ligaments. It takes nearly three months for the re-created ligaments to get really strong. That is why most patients will have to use crutches for 6 to 8 weeks and why the rehabilitation is typically much slower than for a single ligament injury.

Because the surgery is very extensive, the risk of complication is higher. The most common complication is recurrent instability. At the opposite spectrum patients may develop stiffness or loss of motion. Rarely, the patient will require a manipulation or a repeat arthroscopic procedure to remove scar tissue. Because the surgery is performed around major nerves and blood vessels, injury to these structures can occur which may demand additional surgical treatment, although this is rare.