Ligament injuries of the knee

1) What are the ligaments of the knee?

The knee joint has 4 main ligaments. The ligaments are rope like structures, made out of a protein called collagen. They are designed to stabilize the joint against excessive movements in one particular direction. They include the following:

a)      Anterior cruciate ligament (ACL)

b)      Posterior cruciate ligament (PCL)

c)      Medial collateral ligament (MCL)

d)      Lateral collateral ligament (LCL)

 Each of the above ligaments has a specific function in the knee & tear of any one of these or a combination makes the knee unstable for day to day living & active sport.

2) How does the injury happen?

Ligaments require a lot of force to get injured & hence only a high velocity trauma, like that sustained during road traffic accidents & competitive sports can injure them. One or several ligaments may be injured in the process. Generally if the ligament is injured, the bone is spared from fracture, but severe trauma can fracture the bone & rupture the ligament. Sometimes, especially in children & adolescents, the ligament can be torn off with a small piece of bone.

3) What are the symptoms of ligament injury?

Apart from causing a lot of knee pain, an acute injury is always accompanied by a joint hematoma (swelling due to blood accumulation). It is not possible to fully straighten the knee due to this & the patient keeps the knee bent 5-10 degrees. Walking is very difficult & painful.

In a chronic ligament injury, the patient feels that the knee is unstable, both during straight-line walking & particularly on changing direction, descending stairs & walking on uneven surfaces. The knee may also swell up, off & on. The direction of instability depends on which ligament/ set of ligaments is torn.

4) How is acute injury of ligaments treated?

An X ray of the knee is always taken to rule out fractures or avulsion injuries (when the ligament tears off with a small piece of bone). Acute injuries are rested in a brace or a plaster. Ice is applied & anti-inflammatory medicines are prescribed. A pair of crutches needs to be used temporarily, till the ligament heals fully. Once healing has taken place, physiotherapy allows you to gradually return to your pre-injury level of activities. Note that each ligament of the knee has its own specialized & individualized treatment protocol & if more than one ligament is injured, the treatment may take a totally different direction.

5) What is the treatment of chronic ligament injury?

A ligament injury is called chronic if 6 weeks or more have elapsed since the injury. God has bestowed good healing power to the medial collateral ligament (MCL). To a certain extent an isolated posterior cruciate ligament (PCL) injury can also heal with good physiotherapy & proper splintage. ACL & LCL injuries usually do not heal themselves & require reconstructive surgery, if symptoms of instability are present. ACL & PCL reconstruction can be done arthroscopically. LCL & MCL are located outside the knee capsule & require a mini open surgery for reconstruction.

6) What is the usual hospitalization & recovery period after a ligament reconstruction?

One day hospitalization is required for most ligament reconstructions. A graft needs to be taken, either from the front of the knee (bone patella graft) or from the hamstrings. Screws & other implants need to be used to fix the ligament in the bones till they heal. Healing times vary from one ligament to the other, but generally it takes 6 weeks to 3 months to heal fully. Your mobility is not hampered after surgery. Infact in most instances you are out of bed & moving about, the very next day after the surgery.