What to expect if you've torn your anterior cruciate ligament

“The ACL or anterior cruciate ligament is in the centre of the knee, important primarily for rotational stability of the knee. It enables stepping, pivoting, and changing direction activities,” Orthopaedic Surgeon, Queensland-based Dr Brett Collins said. Typical candidates for a torn ACL play sports involving these movements, such as football, netball or skiing.

“A torn ACL is almost always a significant acute (sudden) traumatic injury. Descriptions patients give are usually of a situation where their foot is planted and they change direction and feel their knee give way.

“Normally they will feel immediate pain and a significant reduction in range of movement, and will often need assistance to get off the field or court.”

Treatment options

If required, ACL surgery involves “reconstruction rather than repair,” Collins said.

“Younger patients are better treated with an ACL reconstruction, and [many] middle-aged patients will be as well, depending on their demands.

“Reconstruction allows you to get back to high demand activities with a stable knee, and is potentially protective of other injuries that may occur with further instability - such as a meniscal (knee cartilage) tear which would jeopardise the long-term health of the knee.

“It is usually not a particularly painful procedure, but the patient may need [over-the-counter] pain relief for [up to] a week. Some may need slightly stronger pain relief.

“As a starting point, the patient should approach rehab as a 12-month program, and can take a year to [return] to all their regular activities. Initially it is just about recovering from the surgery and getting a normal range of movement and gait back.”

Progressively, strength and balance-based rehabilitation will be worked on with a physiotherapist.

“Patients can normally run in a straight line about four months after surgery and can start adding change-of-direction rehab after about six months.” Compliance with daily at-home exercises is key.

“It’s also worth discussing with people getting into their 30s or 40s whether they want a reconstruction…[Many] will say what they now do for recreation [doesn’t involve] at-risk activities.

They’re not running around the football field anymore.”

With rest, icing, compression and early physiotherapy opposed to surgery, “some middle-aged people without a reconstruction can walk around and do daily activities.” Pain should settle within two to six weeks, depending on other injuries involved, Collins said.

Rerupture risk

“This decreases the older you are when you have your reconstruction,” Collins said. “The highest risk group for rerupture is teens, with a rerupture rate of approximately 15 per cent.”

Activities returned to, and “surgical factors such as the diameter of graft and placement of the ACL in the knee” are other influencing factors.

“This is [currently] a big area of ACL research. Techniques to reduce rerupture rate in high risk groups – such as secondary procedures [in the surgery] to augment the repair by tightening some of the lateral structures of the knee, are often considered.

“There’s also a reasonable amount of evidence that certain exercise programs are ACL-protective. These are starting to be incorporated into more sporting programs and involve strengthening exercises done at the start of training and game sessions.

“[When] done consistently, these have shown to reduce ACL rupture rate. FIFA were heavily involved with this,” Collins said, referring to the injury-prevention program FIFA 11+. The KNEE Program by Netball Australia has the same purpose.