What is the Meniscus?
The meniscus is a crescent shaped fibrocartilage shock absorber. There are two in each knee:
- Inner side (medial meniscus)
- Outer side (lateral meniscus)
The menisci have the following important functions:
- Reduce wear
- Protect against arthritis
- Assist with stability of the knee joint, and
- Help disperse synovial fluid around the knee joint effectively, thereby assisting with lubrication
Blood flow to the menisci is peripheral and decreases with age. This leads to very poor rates of healing, especially in adults, when the meniscus is damaged.
What is a Meniscal Tear?
Meniscal tears are very common injuries, and are a common cause of knee pain and dysfunction. The meniscus can tear as a result of trauma, age related wear, or a combination of both factors.
Causes of Meniscal Tears
A torn meniscus is one of the most common knee injuries.
Any activity that causes you to forcefully twist or rotate your knee, especially when under weight bearing load can lead to a torn meniscus. A sudden pivot or turn, deep squatting, or heavy lifting can lead to injury.
Meniscal tears commonly occur with ligament problems such as torn ACL
Meniscal tears can be:
Degenerative – occur as part of the aging process due to progressive wear or as a result of habitual, prolonged activities such as squatting, kneeling twisting etc.
Sometimes no trauma is required as the meniscus stiffens and weakens with age.
Traumatic – may occur in the athletic or work settings.
The meniscus is at risk of tearing due to constant exposure by repetitive loading as we walk, run and perform other activities.
When the knee is partially bent under load or involved in twisting motions (pivoting during sports, squatting, heavy lifting and changing direction) the meniscus can deform under pressure.
Higher risk sports include:
Higher risk work includes
- Coal miners both underground and open cut.
Meniscal tears can also occur in combination with tears of ligaments around the knee (e.g. ACL tear).
Symptoms of a Torn Meniscus?
Meniscal tears may cause some or all of the following symptoms:
- Knee pain
- Difficulty walking
- Loss of full range of motion. Stiffness .
- Inability to either bend or fully straighten the knee
- Pain with walking
- Tenderness along the joint line
- A tendency for your knee to get “stuck” or lock up
- Loss of trust
Typically meniscal pain is a severe, intermittent sharp pain localised to one side of the joint and can be experienced when a meniscus is injured, particularly when trying to straighten, bend or twist on the knee. However it is possible to have no pain with meniscal tear and the meniscal injury only becomes evident as a result of swelling and restricted knee movement.
Painful functional instability may be present and this can be difficult to distinguish from true instability resulting from an ACL rupture.
Meniscal Tear Diagnosis
Meniscal tears are diagnosed by the following
- History of injury
- Nature of knee pain and other symptoms
- Careful physical examination of both knees
- Imaging tests
X-rays are useful in the diagnosis of fractures and osteoarthritis
MRI scans are usually accurate for imaging meniscal tears, cartilage injuries and bony abnormalities such as bone bruising and insufficiency fractures.
In patients who are unable to have MRI , like people with cardiac pacemakers or spinal pain stimulators CT with arthrography can be considered as an advanced imaging technique.
Arthroscopy is a surgical procedure in which the inside of a joint is viewed by insertion of a fibreoptic telescope (arthroscope)
The arthroscope contains a camera that allows direct visualization of all the structures in the knee joint.
Small operating instruments can be inserted into the knee through a second small incision
The benefits of arthroscopy include
- Small incisions
- Fast healing
- Rapid recovery, and
- Little scarring
Arthroscopic surgical procedures can be performed on an outpatient basis. This means patients can return home on the same day as the procedure.
Risks With Knee Arthroscopy?
Complications are not common but can occur with any surgery.
Prior to making any decision to have surgery, it is important that you understand the potential risks so that you can make an informed decision regarding the advantages and disadvantages of surgery.
The following list is by no means exhaustive, so it is important to discuss your concerns with me.
General surgical risks include:
- Risk of infection,
- Postoperative bleeding
- Blood clots in the leg (deep vein thrombosis – DVT) or lung.
Apart from surgical risks, medical (including allergies) and anaesthetic complications can occur, and these can affect your general health and well-being.
Treatment for a Meniscal Tear?
Unfortunately, meniscal tears may not heal without surgery.
Not everyone requires meniscal surgery and treatment is tailored to the patient’s individual needs. The less active patient may be able to return to a quieter lifestyle without surgery.
At arthroscopy, the torn meniscus will be repaired with sutures or partly resected and reshaped to a stable configuration, depending on the site and nature of the tear.
Arthroscopy is very effective in treating the symptoms of meniscal tears.
Surgery is recommended where patients endure ongoing episodes of
- Swelling and
Certain types of meniscal tears can cause damage to the articular cartilage if left untreated. This can contribute to the development of premature osteoarthritis.
Non-surgical treatment typically involves physical therapy and rehabilitation to strengthen the quadriceps and hamstrings muscles to help stabilise the knee and maintain range of movement. Aggravating activities should be avoided and a trial of time should take place often for 6-12 weeks to see if symptoms will settle. If the meniscus is stable and the patient’s symptoms have settled or are manageable without being intrusive on lifestyle no further treatment or intervention may be required.
The exception to this pathway is an acutely locked knee from a “bucket handle” displaced vertical meniscal tear . A locked knee is typically an acutely very painful event where the knee joint is stuck in near 40 degrees of flexion and patient unable to fully straighten the knee. Typically a locked knee requires early surgery to unlock the knee and either repair or remove the displaced meniscus .
Once the meniscus has torn the protective shock absorbing and stabilising function is no longer present. At surgery usual practice is that non functional meniscal tissue which is torn is removed. Every effort is made to preserve as much of the meniscus as possible .
In some cases where the meniscal tear is extensive and a large meniscal fragment is damaged and removed a patient may have an increased risk of developing osteoarthritis of the knee in the long term.
The nature of the meniscal tear rather than the arthroscopic procedure has increased risk of arthritic development .
Patients will usually require surgery to restore function and stability if they wish to return to:
- Sports involving cutting or pivoting movements e.g. soccer, football and netball, etc, or
- Physical jobs e.g. the military, policeman, fireman, builders, etc.
The procedure for meniscal repair is performed via knee arthroscopy (ie. keyhole surgery) with 2 small cuts (5-7mm) on each side of the knee cap.
Risks with Meniscal Surgery
Complications are not common but can occur. Prior to making any decision to have surgery, it is important that you understand the potential risks so that you can make an informed decision regarding the advantages and disadvantages of surgery.
The following list is by no means exhaustive. Joint stiffness
- Local nerve or blood vessel damage
- Bleeding into the knee
- Infection (extremely rare)
- Blood clots and DVT
- Other rare complications, e.g. reflex sympathetic dystrophy, also known as complex regional pain syndrome. This rare condition is not entirely understood but can cause unexplained and excessive pain and stiffness after surgery or after a trivial injury
It is important to discuss any concerns you may have with me prior to surgery and to read the patient information handout that will be given to you . If in doubt about proceeding to surgery the recommended option is to delay surgery and return to my office for further discussion.
Preparing for Meniscal Repair Surgery
Once it has been decided that surgery is required, preparation is necessary to achieve the best results and a quick problem free recovery.
Preparing mentally and physically for surgery is an important step toward a successful result.
- I usually recommend you have seen a physiotherapist before surgery and exhausted a trial of non operative management
- A treatment plan will be created specifically tailored for you
- I will need a complete list of your medications so that I can advise which ones should be stopped prior to surgery.
- The admitting hospital will advise you of the fasting time and your arrival time on the day before surgery
- Do not eat or drink anything, including water, for 6 hours before surgery
- Do not Stop taking aspirin, warfarin, NOACS which are cardiac or CVA protective without discussion with your General Practitioner or myself.
- Stop smoking to reduce your surgery risks and improve your recovery
After Your Operation:
You will be given a prescription for painkillers and possibly anti-inflammatory medications
The wounds take 7-14 days to heal. Most patients improve dramatically in the first 2 weeks.
Occasionally, there are periods where the knee may become sore and then settle again. This is part of the normal healing process. If a meniscal repair (suturing the meniscus) was performed, it can take 3 months for it to heal fully.
Full weight-bearing and walking is allowed immediately after meniscal surgery. Some patients do not need walking aids like crutches after arthroscopic surgery, but the hospital will supply them and instruct you on correct use before discharge . Crutches can usually be discarded after a day or two in most cases.
When can I Drive After Meniscal Surgery?
Driving a car is discouraged for 48 hours after an anaesthetic. After 48 hours, your ability to drive will depend on the side you had your operation, left or right, and the type of vehicle you drive, manual or automatic. You can drive whenever you feel comfortable and are walking well with good control over your legs and reflexes. You should not drive under the influence of strong painkillers, e.g. Endone or Codeine.
Return to Work and Activity After Meniscal Surgery
I will provide you with a medical certificate at time of your discharge from Hospital and at your first post-operative visit if required.
You may return to work as your knee function improves well enough for you to do your particular job.
Return to work and other activities will vary depending on the procedure performed and type of work you do. Most patients can return to office work within a few days. Labour intensive work however, may require up to 6-8 weeks or longer before returning to full duties.
During this period you should try to avoid the following activities:
- Prolonged standing
- Heavy lifting
- Bending or
- Excessive stair climbing
There can be risks of stress responses or even stress fractures if too much activity takes place following the arthroscopy
It is normal for there to be some discomfort in the knee for several weeks after arthroscopic surgery.
Often there is little pain after surgery. The anaethetist will provide a script for painkillers. Over activity or standing for long periods can increase the swelling and pain in the knee. Try and rest as much as possible in the first few days.
Arthroscopy of the knee is a safe and effective procedure. The results of arthroscopic surgery are usually better than open forms of surgery. Complications are uncommon. Remember that every knee is unique, and recovery time and the results of the procedure reflect that uniqueness. Not all knees can be made better as there may be some damage that cannot be reversed.