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Arthroscopy
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Knee Arthroscopy
The arthroscope is a fibre-optic telescope that can be inserted into
a joint (commonly the
knee, shoulder and ankle) to evaluate and treat a number of conditions.
A camera is attached
to the arthroscope and the picture is visualized on a TV monitor. Most
arthroscopic surgery is performed as a Day-Only procedure and is usually
done under general anaesthesia.
Arthroscopy is useful in evaluating and treating the
following conditions
1. Torn floating cartilage (meniscus): The cartilage is trimmed to a
stable rim or
occasionally repaired
2. Torn surface (articular) cartilage
3. Removal of loose bodies (cartilage or bone that has broken off)
and cysts.
4. Reconstruction of the Anterior Cruciate ligament
5. Patello-femoral (knee-cap) disorders
6. Washout of infected knees
7. General diagnostic purposes
Basic Knee Anatomy
The knee is the largest joint in the body. The knee joint is made up
of the femur, tibia and
patella (knee cap). All these bones are lined with articular (surface
cartilage). This articular
cartilage acts like a shock absorber and allows a smooth low friction
surface for the knee to
move on. Between the tibia and femur lie two floating cartilages called
menisci. The medial
(inner) meniscus and the Lateral (outer) meniscus rest on the tibial
surface cartilage and are
mobile. The menisci also act as shock absorbers and stabilizers. The
knee is stabilized by
ligaments that are both in and outside the joint. The medial and lateral
collateral ligaments
support the knee from excessive side-to-side movement. The (internal)
anterior and posterior cruciate ligaments support the knee from buckling
and giving way. The knee joint is surrounded
by a capsule (envelope) that produces a small amount of synovial
(lubrication) fluid to help with smooth motion. Thigh muscles are
important secondary knee stabilizers.
Investigations:
A routine X-Ray of the knee which includes a standing weight-bearing
view is usually required.
An MRI scan which looks at the cartilages and soft tissues may be needed
if the diagnosis is
unclear. There is little value in the use of Ultrasound in investigating
knee problems.
Meniscal Cartilage Tears:
Following a twisting type of injury the medial (or Lateral) meniscus
can tear. This results either
from a sporting injury or may occur from a simple twisting injury when
getting out of a chair or standing from a squatting position. Our
cartilages become a little brittle as we get older and
therefore can tear a little easier. The symptoms of a torn cartilage
include
- Pain over the torn area i.e. inner or outer side of the knee
- Knee swelling
- Reduced motion
- Locking if the cartilage gets caught between the femur and the
tibia
CARTILAGE TEARS
Once a meniscal cartilage has torn it will not heal unless it is a
very small tear which is near the capsule of the joint. Once the
cartilage has torn it predisposes the knee to develop osteoarthritis
(wear and tear) in 15 to 20 years. It is better to remove torn pieces
from the knee if the knee is symptomatic.
Torn cartilages in general continue to cause symptoms of discomfort,
pain and swelling until the loose, ragged pieces are removed. Only the
torn section is removed and the knee should recover and become symptom
free. If the entire meniscus is removed, the knee will develop
osteoarthritis
in 15 to 20 years. Now a days only the torn section is removed and it is
hoped that this will delay
the onset of long-term wear and tear osteoarthritis.
Occasionally, provided the knee is stable and the tear is a certain
type of tear in a young patient (peripheral bucket handle tear), the
meniscus may be suitable for repair. If repaired one has to
avoid sports for a minimum of three months.
Articular Cartilage (Surface) injury:
If the surface cartilage is torn, this is most significant as a major
shock-absorbing function is compromised. Large pieces of articular
cartilage can float in the knee (sometimes with bone attached) and this
causes locking of the joint and can cause further deterioration due to
the
loose body floating around the knee causing further wear and tear. Most
surface cartilage
wear will ultimately lead to osteoarthritis. Mechanical symptoms of pain
and swelling due to cartilage peeling off can be helped with
arthroscopic surgery. The surgery smoothes the edges
of the surface cartilage and removes loose bodies. Unstable cartilage
can be removed. It is common for the surgeon to then perform micro
fracture. This is where a small, sharp pick is
used to perforate the underlying bone and encourage healing of the
cartilage defect. This can
result in a good outcome, but does not replace the defect with normal
cartilage.
Occasionally cartilage replacement is required. This can be achieved
using various techniques.
The most common way of treating smaller defects is by a method known as
mosaicplasty.
This is where small cylinders of bone and cartilage are harvested from a
less
important area of the knee and packed into the defect, creating a
cobblestone-like repair,
with true cartilage.
The other method of cartilage replacement used is Autologous
Chondrocyte Transplantation.
It involves harvesting cartilage cells from the affected knee, sending
these cells to a laboratory
and then culturing the cells to multiply into many cells. The large
amounts of cells produced are then placed back into the affected knee,
into the defect requiring resurfacing.
Results are still short term but are looking encouraging. After a major
cartilage or ligament
injury has been treated the knee can return to normal function. There is
however a small
increasein the risk of developing long term wear and tear
(Osteoarthritis) and depending
on the degree of injury, activity modification may be required.
Activities that help prevent
knees deteriorating quickly include:
- Low impact sports like swimming, cycling and walking
- Reducing weight and maintaining a healthy diet
Anterior Cruciate Ligament Injuries:
Rupture of the Anterior (rarely the posterior) Cruciate Ligament
(ACL) is a common sporting injury. Once ruptured the ACL does not heal
and usually causes knee instability and the inability to return to
normal sporting activities. An ACL reconstruction is required and a new
ligament is fashioned to replace the ruptured ligament. This procedure
is performed using the arthroscope.
Patella (knee-cap) disorders:
The arthroscope can be used to treat problems relating to kneecap
disorders, particularly
mal-tracking and significant surface cartilage tears. Patients may need
to stay overnight if
a lateral release has been performed as knee swelling is quite common.
The majority of
common knee -cap problems can be treated with physiotherapy and
rehabilitation
Inflammatory Arthritis:
Occasionally arthroscopy is used in inflammatory conditions (e.g.
Rheumatoid Arthritis) to help reduce the amount of inflamed synovium
(joint lining) that is producing excess joint fluid. This procedure is
called a synovectomy. After the surgery a drain is inserted into the
knee and
patients generally require one or two nights in hospital.
Bakers cysts:
Bakers cysts or popliteal cysts are often found on clinical
examination and ultrasound / MRI scan. The cyst is a fluid filled cavity
behind the knee and in adults arises from a torn meniscus or worn
articular cartilage in the knee. These cysts usually do not require
removal as treating the cause (torn knee cartilage) will in most cases
reduce the size of the cyst. Occasionally the cysts rupture and can
cause calf pain. The cysts are not dangerous and do not require
treatment if the knee is asymptomatic.
Arthroscopy of the knee: Patient Information
Please stop taking Aspirin and Anti-inflammatories 5 days prior to
your surgery. If pain
medication is required use Panadol / Panadine or Panadine Forte. You can
continue taking all
your other routine medication. If you smoke you are advised to stop a
few days prior to your surgery.
You will be admitted on the day of surgery and need to remain fasted
for 6 hours prior to the procedure.
The limb undergoing the procedure will be marked and identified prior
to the anaesthetic
Once you are under anaesthetic, the knee is prepared in a sterile
fashion. A tourniquet is placed around the thigh to allow a ‘blood –
free' procedure.
The Arthroscope is introduced through a small (size of a pen)
incision on the outer side of the
knee. A second incision on the inner side of the knee is made to
introduce the instruments that allow examination of the joint and
treatment of the problem.
- You will wake up in the recovery room and then be transferred back
to the ward
- A bandage will be around the operated knee.
- Once you are recovered your drip will be removed and you will be
shown a number of exercises to do.
- Your Surgeon will see you prior to discharge and explain the
findings of the operation
and what was done during surgery.
- Pain medication will be provided and should be taken as directed
- You can remove the bandage in 24 hours and place waterproof
dressings (provided)
over the wounds.
- It is NORMAL for the knee to swell after the surgery. Elevating
the leg when you are
seated and placing Ice-Packs on the knee will help to reduce swelling.
(Ice packs on
for 20 min 3-4 times a day until swelling has reduced)
- You are able to drive and return to work when comfortable unless
otherwise instructed
- Please make an appointment 7-10 days after surgery to monitor your
progress and
remove the 2 stitches in your knee.
Risks of Arthroscopy:
General Anaesthetic risks are extremely rare. Occasionally patients
have some discomfort
in the throat as a result of the tube that supplies oxygen and other
gasses. Please discuss
with the Specialist Anaesthetist if you have any specific concerns
Risks specifically related to the surgery.
Risks related to Arthroscopic knee surgery include:
- Postoperative bleeding
- Deep Vein Thrombosis
- Infection
- Stiffness
- Numbness to part of the skin near the incisions
- Injury to vessels, nerves and a chronic pain syndrome
- Progression of the disease process
The risks and complications of arthroscopic knee surgery are
extremely small. One must
however bear in mind that occasionally there is more damage in the knee
than was initially
thought and that this may affect the recovery time. In addition if the
cartilage in the knee is
partly worn out then arthroscopic surgery has about a 65% chance of
improving symptoms
in the short to medium term but more definitive surgery may be required
in the future. In
general arthroscopic surgery does not improve knees that have well
established Osteoarthritis.
| Post –Operative Exercises and
Physiotherapy |
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Following your surgery you will be given an instruction sheet showing
exercises that are helpful
in speeding up your recovery. Strengthening your thigh muscles
(Quadriceps and Hamstrings) is most important. Swimming and cycling
(stationary or road) are excellent ways to build these muscles up and
improve movement.
Frequently asked questions:
How long am I in Hospital?
A: Approx 4 hours
Do I need crutches
A: Usually not required (Unless having Anterior Cruciate Ligament
Reconstruction)
When can I get the knee wet
A: After 24 hrs remove the bandage and apply waterproof dressing
When can I drive
A: After 24 hrs if the knee is comfortable
When can I return to work
A: When the knee feels reasonably comfortable
When can I swim
A: After removal of the stitches
How long will my knee take to recover
A: Depending on the findings and surgery usually 4 to 6 weeks
following the surgery.
When Can I return to Sports
A: Depending on the findings, 4-6 weeks after surgery
After ACL reconstructing 6-9 months for return to full sports such as
soccer, rugby, netball.
After articular cartilage surgery it can be up to 6 months.
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