Frequently Asked Questions (FAQ) about
Anterior Cruciate Ligament Surgery
(ACL Surgery)

What is the ACL and what is its function?

The ACL (Anterior Cruciate Ligament) is a part of the knee joint providing stability especially for movements involving pivoting/twisting actions. Stability is especially important for sports which involve changing direction while moving at speed (like tennis, football, or skiing).

How can I tell if I tore my ACL?

Sometimes it's difficult to tell. When you tear your ACL it feels a lot "looser" than your good knee. This loss of stability is the telltale factor. At the time of injury, pain and swelling are common but these can be present in other situations as well and can complicate the examination. You should consult your doctor to determine whether a torn ACL is likely. If clinical testing is inconclusive and it is very important to know at an early stage whether the ACL is torn, a special test called an MRI (Magnetic Resonance Imaging) Scan can be done.

Why should I have surgery?

The primary purpose of the procedure is to reduce instability in the knee caused by the absence of an ACL that is functioning well. Hopefully, this will allow you to resume pivoting activities without fear of having the knee give way. Bracing can be a good alternative to surgery.

How does the surgery work?

Repairing the original ligament is not possible. Instead, tendons (from the hamstring, patella, or quadriceps) will be used to construct a ligament. Tunnels will be drilled in the lower leg (tibia) and thigh (femur) to approximate the attachments of the original ligament using fixation devices.

Do I really need surgery?

As with any surgery there are a number of considerations. Will the injury stop you from doing things you enjoy life? Will failure to repair the injury allow more damage? Each case is specific to an individual and depends on lifestyle and the severity of the injury. If the knee is unstable, cartilage wear & tear can occur more quickly than normal, leading to arthritis of the knee joint. You should discuss this with your doctor.

Can ACL injuries lead to other surgery?

It is not uncommon to find torn cartilage (menisci) which can be dealt with at the time of surgery either by removing or repairing the torn pieces of the meniscus. This should be discussed with your doctor prior to surgery.

Should I have the graft taken from the hamstring or patellar tendon?

I typically choose to take a graft from the hamstring. If it turns out to be necessary to harvest the patellar tendon it is common to experience ongoing discomfort over the front of the knee cap. This can be sufficiently painful to make kneeling impossible. As well, risk of fracture of the knee cap is associated with this choice of graft but consult your doctor. In general, the pain, length of hospital stay and size of scar are all less with the hamstring tendon technique. You should discuss the advantages/disadvantages of the different reconstructions with your doctor. Alternatively, allograft on donor tendon can be utilized.

Should I use a general or local anaesthetic?

A general anaesthetic means you will be unconscious during the surgery and should have no recollection aside from going to sleep and waking up. A local anaesthetic allow you to remain conscious without feeling pain. Typically we use a spinal anesthetic which blocks all pain in the area while leaving the patient conscious. This is a personal choice and can be discussed with the anaesthesiologist.

Do I need to donate blood prior to surgery?

Rarely complications during surgery can lead to rapid blood loss and require a blood transfusion. If this concerns you then you should discuss this possibility with your doctor.

How long is the stay in Hospital?

This operation is performed as daycare surgery. Discharge from the hospital or clinic will be the same day.

How will pain be handled?

  1. A prescription for pain medication will be provided.
  2. The knee will be infiltrated with local anaesthetic which usually blocks any pain for 12 to 16 hours.
  3. Icing will be helpful. My office has available a motorized cooling unit which will significantly help reduce postoperative pain and swelling.

Will I need crutches?

Though early mobilization after surgery is important to prevent complications a cane or crutches are necessary initially. Full weight-bearing is usually allowed as tolerated. As with everything, this is something to confirm with your doctor -- complications such as meniscal repair during surgery might influence the progress of recovery.

Will I have to wear a brace?

Very rarely wearing a brace for up to six weeks may be recommended, based on the assessment made during surgery of the strength of the new ligament construct.

How long will recovery take?

Everyone recovers at a different rate and rehabilitation after surgery is individualized. Guidance by a physiotherapist is usually helpful. In general, I follow the following 'brace free, rapid recovery' protocol:

  • Week 1 & 2. Phase of wound healing. Walking as tolerated may use crutches or a cane. No formal exercises.
  • Week 3-6. Phase of preliminary ligament fixation by bone in the tunnels. Gentle range of motion exercises, swimming (no whip kick), light cycling.
  • Week 7-12. Phase of preliminary ligament maturation. Increased cycling intensity as tolerated, swimming, elliptical stepper, deep water walking/running. May start light weight training, focus on hamstring strengthening.
  • Week 12-16. May start controlled jogging on a treadmill.
  • Week 17 onward. May start exploring agility exercises to return to desired sport.

Usually 6-12 months most activities can be resumed. Discuss any specifics with your doctor and physiotherapist.

Does physical therapy hurt and is it very difficult?

Physical Therapy usually is not painful but, as mentioned, each case is individual. On occasion the physiotherapist uses some force to enhance the range of motion.  The rate and type of physical therapy and rehab is something to discuss with your doctor and therapist if you are in too much discomfort.

When can I take a bath/shower?

It is important to make sure the wound is healed enough so the risk of infection is minimized. As long as the wound is kept dry, showering is allowed. It will take at least 2 weeks before bathing or swimming is safe.

I've heard that the operation can cause residual discomfort and swelling or occasionally numbness. Is this true?

These issues usually settle in the course of six months, occasionally a year. On occasion, numbness in a patch just below the knee will persist.

What sorts of complications can occur?

General complications, as in all surgery, such as infection and venous thrombosis after surgery can occur but are not very common. See consent form.

Can re-injury of my ACL (another tear) be prevented?

ACL injury is associated with multidirectional sport so refraining from these sports is a way to minimize the chance of (re)injury. In all sports, a stabilising knee brace could offer some protection but there is no sure way to prevent these injuries occurring in these sports.

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