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KNEE JOINT
ALTERNATIVE
OPERATIONS
Contents
Arthroscopic "shaving" and other procedures
Transplantation of tissues and cells
Osteotomy
Arthrodesis
Arthroscopic
- key hole- operations
Meniscus resection
In patients with moderate osteoarthritis of the knee joint,
the patient may complain more of stiffness, catching, and other difficulties to move the
knee joint than the pain itself. These complaints may be caused by rupture of the
degenerated meniscus, by a piece of avulsed joint cartilage or by roughly joint surfaces
that hinder free motion in the knee joint.
The surgeon can examine the knee with an arthroscope and
remove the hindrances
The surgeon may remove the torn meniscus, remove the large
pieces of avulsed joint cartilage that float in the joint space, shave the rough joint
cartilage surfaces to a clean, smooth level. This is called arthroscopic
débridement.
The value of this procedure for treatment of knees damaged
with osteoarthritis is still discussed. Large statistics show that 70 % of all patients
>70 years of age were still satisfied with their knee three years following
arthroscopic débridement. (Wai 2002).
The advantages:
It is a small procedure with few risks, that is suitable
for older patients.
The disadvantages:
The procedure offers seldom a lasting cure for
ostoarthritic complains.
In older patients this procedure may unnecessarily postpone
a total knee replacement which offers a definitive treatment of osteoarthritic knees.
Transplantation
of knee joint tissues and cells
Transplantation of patients own living
cartilage cells.
This operation method is not applicable for knee joints
damaged with osteoarthritis or any other more widespread joint disease.
Ideal patients for this method are young people with small
isolated defects in the knee joint cartilage, preferably in the cartilage of femoral
condyles.
These small, contained cartilage defects cause serious
troubles to the young people but they are not osteoarthritis - they can, however, develop
into osteoarthritis if untreated.
For more information one this method see
http://www.carticel.com
Transplantation of a whole joint cartilage surface
from amputated limbs.
In young patients with osteoarthritis limited only to one
knee joint compartment, one may (at least theoretically) replace the worn out joint
surfaces with new joint surfaces taken from amputated limbs.
As an alternative, one may place a new buffer - a new
meniscus - between the worn out knee joint surfaces.
This is a theoretically sound idea:
The cells of joint cartilage are used to starving - they
receive their nourishment from joint fluid. Thus, they survive excellently the
transplantation.
The cells of joint cartilage are embedded in an avascular
substance - cartilage matrix. Thus, they neither provoke rejection reaction in the host,
nor will be influenced by such a reaction.
The advantages of this operation are:
less destruction of patients own skeleton, win time
for a later total knee replacement
The disadvantages
limited supply of knee joint tissues from amputated limbs,
risk of blood transmitted infections, death and rejection of the transplanted tissues (in
spite of theory)
These transplantation operations are carried out at very
few Centra around the world on strictly experimental basis.
Osteotomy
In a knee joint with only one joint compartment
destructed by osteoarthritis, the mechanical axis goes no longer through the middle of the
knee joint. Instead, the stresses concentrate on the already damaged compartment. Due to
this concentration of stresses the cartilage damage continues and increases.
The surgeon may repair the distorted mechanical axis to the
normal again. The operation is called osteotomy. Both knee joint bones may be operated on,
but the most usual is the operation on the shinbone - tibia.
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Click on the icon for a full size picture High tibia osteotomy
it is called high because it is is carried out high on the
tibia, close to the knee joint.
In this picture the inner (medial) compartment is damaged,
the joint cartilage in the outer compartment is healthy.
A - The mechanical axis passes outside the knee joint, the
knee is bent. The body weight (Red Arrow) passes through the already damaged medial
compartment and damages it still more. The healthy outside part of the knee joint is not
loaded.
The surgeon should change the limb axis so that the healthy
outside of the knee joint will take the load.
The surgeon divides the tibia (the shinbone) below the knee
joint (high) and takes out a wedge of bone on outside.
B - Then the surgeon pushes the lower part of the
tibia to the outside. The divided bone ends come into contact and are stabilized in
that corrected position by a plate and screw.
In this new position of the tibia, the body weight
now passes through the healthy cartilage on the outside of the knee joint. (Blue Arrow) |
The ideal candidates for this operation are young patients
with damage in only one knee joint compartment and with a well-retained motion in their
knees.
Advantages
Lesser operation, does not open the knee joint, less risk
for infection in the knee joint
Disadvantages
long rehabilitation with only partial weight bearing, risk
of failed healing of the osteotomy and recurrence of the deformity
Statistics show that about 65 - 75 % patients were still
satisfied with the result of the tibial osteotomy ten years after the operation.
The results of total knee replacement carried out after the
high tibia osteotomy are not worse than the results in other patients. The operation is,
however, more difficult and followed by higher rates of complications.
Arthrodesis - fusion
of the knee joint
Nowadays, this operation is not an alternative for a total
knee replacement. Instead, it may be the last operation after a failed total knee
prosthesis.
In large statistics, arthrodesis of the knee joint was
carried out in 0,0012% of patients with failed total knee replacement (Robertsson 1999).
After this operation the knee joint is gone and gone is
also the pain. The knee joint is totally stiff.
References:
Wai et al J Bone Joint Surg-Am 2002; 84-A.: 17-22
Robertsson O et al Acta Orthop Scand 1999;70:467-72
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