It is generally recommended to have surgery if you wish to get back to sports which involve pivoting. Occasionally, knees can be unstable during activities of daily living and if this is the case you should have surgery. It is not absolutely necessary to have this ligament reconstructed. In general, the younger and more active you are then the stronger the recommendation for reconstruction.
We also recommend surgery in people with dangerous occupations, for example policemen, firemen, roof tilers and scaffolders. This is a safety issue, to prevent instability in at risk situations. There is no urgency in performing this operation and in fact, it is sometimes better to allow the knee to settle down and regain a near full range of motion prior to surgery.
Repeated instability or abnormal movement in the knee can cause ongoing damage leading to stretching of other structures around the knee, meniscal tears or arthritis in the long term. If you do not elect to have surgery it is strongly advised that you give up sports which involve pivoting.
With specialised surgeons who perform a lot of these operations, results are very successful (in the order of 95%) and complications rare but still can occur. This is an elective procedure and as the patient you need to make an informed decision on whether or not to proceed with surgery.
The anterior cruciate ligament is one of the major stabilising ligaments in the knee. It is a strong, rope-like structure located in the centre of the knee running from the femur to the tibia.
The anterior cruciate ligament prevents the tibia moving forward and rotating abnormally on the tibia. When it ruptures it does not heal itself and the knee often becomes unstable or gives way. Often associated with the cruciate ligament rupture there can be damage to other structures in the knee such as bone, cartilage or menisci and these injuries may also need to be addressed at the time of surgery.
The operation involves replacing the torn cruciate ligament with either the hamstring tendons or patella tendon from the same leg.
You are taken to the operating room and given an anaesthetic. A tourniquet is applied to your leg to prevent bleeding and it is cleaned and draped in preparation for the operation.
The graft to be used as your new tendon is harvested. This involves taking the hamstring tendons through a small incision just below the knee and fashioning them into a four stranded graft which takes the place of the cruciate ligament.
Tunnels are then drilled in the tibia and femur (the two bones making up the knee joint) and the graft is passed trough this tunnel. The graft is then fixed with various devices at each end to stabilise it and allow it to heal to the bone. The fixation devices are numerous and surgeon specific.
This surgery is all done through the arthroscope using two small incision approximately 1cm each. The inside of the knee is thoroughly visualised and any other problems such as meniscal tears treated at the same surgical setting.
Following the surgery you will have drains in the knee, which are removed the next day and the dressing changed. A splint may be worn for the first week or so purely for comfort and may be removed at any stage to allow the knee to bend. Not all surgeons use splints.
Most patients go home the following day after surgery. You will be seen by a physiotherapist prior to discharge who will teach you how to use crutches and show you some simple exercises to do at home.
For the first 3 days ice packs should be used to reduce swelling 20 minutes at a time as regularly as possible. You can walk around but rest as much as possible for the first week and elevate your leg when sitting. Most patients require crutches for a week or so. You can shower with the dressings on. If there is excessive ooze, these can be changed using antiseptic or can be done by the local doctor if you are worried. Pain is variable and prescription pain killers required for up to a week.
You will be followed up in the rooms seven to ten days following surgery where the dressings will be removed and the wounds inspected. If there is any redness, increased swelling or you have temperatures you should contact the rooms or the hospital where the surgery was performed so they can contact your surgeon.
Time off work depends on your work requirements and are very variable. Office workers usually require 2 weeks off work and manual labourers 2 to 3 months.
Listed below is some information and instructions that will assist you in the recovery period after your knee surgery.
Physiotherapy is an integral part of the treatment and is recommended to start as early as possible. Preoperative physiotherapy is helpful to better prepare the knee for surgery. The early aim is to regain range of motion, reduce swelling and achieve full weight bearing.
The remaining rehabilitation will be supervised by a physiotherapist and will involve activities such as exercise bike riding, swimming, proprioceptive exercises and muscle strengthening. Cycling can begin at two months, jogging can generally begin at around three months. The graft is strong enough to allow sport at around six months, however other factors come into play such as confidence and adequate fitness and training.
Professional sportsmen often return at six months but recreational athletes may take ten to twelve, months depending on motivation and time put into rehabilitation.
The rehabilitation and overall success of the procedure can be affected by associated injuries to the knee such as damage to meniscus, articular cartilage or other ligaments.
Complications in arthroscopic anterior cruciate ligament reconstruction are not common. Despite advances in surgical technique and the utmost care being taken in surgery, complications can still occur. It is very important for patients undergoing this operation to understand the reasons for the procedure and to have a major role in making an informed choice to proceed with surgery rather than non operative treatment. Complications can be related to the surgery or may be due to the anaesthetic. You can read about the risks of any surgery here.
Specific Surgical Complications
Specific complications again are rare and the utmost care is taken during surgery to avoid them. The following is a list of the well described but rare complications, and also unusual complications. Most of these complications are treatable and do not lead to long term problems. Potential complications include:
Excessive swelling and bruising of the leg
This is due to bleeding in the joint and surrounding tissues. It can cause short term pain and make it difficult to bend the knee. To avoid this, ice the leg and elevate it as much as possible.
This occurs in approximately 1 in 200 cases. The procedure is done using antibiotic prophylaxis and in a sterile operating environment to reduce the risk of infection. Treatment involves either oral or intravenous antibiotics and may involve further operations to wash out the joint. Occasionally this can lead to joint stiffness, destruction of the cartilage within the joint or failure of the graft.
This can result from scar tissue within the joint resulting in loss of motion. Modern minimally invasive techniques and rapid rehabilitation makes this less likely than in the past. Treatment consists of physiotherapy or occasionally further surgical procedures. Full range of motion can not always be guaranteed.
Small amounts of bleeding in the joint are normal. Large amounts of bleeding can occur but are more common in patients with bleeding disorders or those taking anti-inflammatory medications. These should be ceased 2 weeks prior to surgery. Excessive bleeding can require aspiration of the knee or occasionally a repeat arthroscopy.
Unsightly scar or wound breakdown
Donor site problems
The choices of graft include hamstrings and middle third patella tendon. There tend to be fewer problems after harvesting hamstrings than after harvesting middle third of the patella. Following hamstring harvest you can get some pain and swelling in the region of the hamstrings at the back of the thigh but this is usually temporary. Weakness in the hamstrings, if it occurs, is usually minimal.
The biggest problem following middle third patella tendon harvest is knee pain at the front, which can cause discomfort with everyday activities, especially kneeling. Occasionally the hamstring tendons are not satisfactory and either the hamstrings of the opposite leg or the patella tendon needs to be taken - this is something that the surgeons will decide during the operation.
The graft is fixed into place with various devices into the bone. These vary from metal or absorbable posts, screws, buttons and staples. These devices can occasionally cause irritation to surrounding structures and require removal. They are only removed once the tendon is grown into the bone and they are no longer required to hold the graft in place.
Anterior knee pain
Some patients develop pain around the kneecap. This is a result of muscle wasting and inactivity following surgery and usually resolves over time with appropriate physiotherapy.
Reflex sympathetic dystrophy
This is a rare condition, the mechanism of which is not fully understood. It involves an overactivity of the nerves in the leg causing unexplained and excessive pain.
Deep Venous Thrombosis
Clots in the leg which may require medical management in the form of injections or tablets to thin the blood. Very rarely these can travel to the lungs (this is called a pulmonary embolism) causing respiratory difficulties or even death.
An extremely rare condition which is due to excessive swelling in the knee cutting off the circulation to the muscles. This requires a fasciotomy operation to relieve this pressure.
This can be unpredictable but is more common in knees with damage to other structures such as menisci or articular cartilage. Arthroscopy can not reverse any damage to the joint surface (arthritis). If unexplained pain does occur then another arthroscopy may occasionally be recommended.
Graft rupture or stretching
This can occur with future injuries. Graft failure is approximately five percent which is about the same risk as rupturing the good cruciate ligament on the other side.
If this occurs the graft can be revised using the tendons from the other leg. The postoperative course for a revision is only slightly slower than normal and the complications much the same.
The graft can stretch over time. The graft is tightest at the time of insertion and some stretching or loosening is inevitable. This is more likely in patients with ligamentous laxity or in patients with damage to secondary stabilisers of the knee (for instance, the other strong ligaments around the knee). Patients who have their operation soon after their injury are more likely to have a more stable knee in the long term before other structures in the knee stretch out. If it does stretch in some cases a brace can assist with return to sport and in other cases it is in the best interest of your knee to give up sport.