Uni Condylar Knee Replacement

Introduction
Arthritis
Advantages & Disadvantages

Introduction

Unicondylar Knee Replacement simply means that only a part of the knee joint is replaced through a smaller incision than would normally be used for a total knee replacement.

Unicondylar Knee Replacements have been performed since the early 1970′s with mixed success. Over the last 25 years implant design, instrumentation and surgical technique have improved markedly making it a very successful procedure for unicompartmental arthritis. Recent advances allow us to perform this through a smaller incision and therefore is not as traumatic to the knee making recovery quicker.

Total Knee Replacement surgery replaces the ends of the femur (thigh bone) and tibia (shin bone) with plastic inserted between them and usually the patella (knee cap).

Arthritis

Arthritis is a general term covering numerous conditions where the joint surface (cartilage) wears out. The joint surface is covered by a smooth articular surface that allows pain free movement in the joint.

When the articular cartilage wears out, the bone ends rub on one another and cause pain. There are numerous conditions that can cause arthritis and often the exact cause is never known. In general, but not always it affects people as they get older (Osteoarthritis).

Other Causes Include

Trauma (fracture)
Increased stress e.g., overuse, overweight, etc.
Infection
Connective tissue disorders
Inactive lifestyle- e.g., Obesity, as additional weight puts extra force through your joints which can lead to arthritis over a period of time
Inflammation e.g., Rheumatoid arthritis

In an Arthritic Knee

The cartilage lining is thinner than normal or completely absent. The degree of cartilage damage and inflammation varies with the type and stage of arthritis
The capsule of the arthritic knee is swollen
The joint space is narrowed and irregular in outline; this can be seen in an X-ray image
Bone spurs or excessive bone can also build up around the edges of the joint

The combinations of these factors make the arthritic knee stiff and limit activities due to pain or fatigue.

Diagnosis

The diagnosis of osteoarthritis is made on history, physical examination & X-rays
There is no blood test to diagnose Osteoarthritis (wear & tear arthritis)

Advantages & Disadvantages

The decision to proceed with Knee Replacement surgery is a cooperative one between you, your surgeon, family and your local doctor.

The benefits following surgery are relief of symptoms of arthritis. These include

Severe pain that limits your everyday activities including walking, shopping, visiting friends, getting in and out of chair, gardening, etc.
Pain waking you at night
Deformity- either bowleg or knock knees
Stiffness

Prior to surgery you will usually have tried some conservative treatments such as simple analgesics, weight loss, anti-inflammatory medications, modification of your activities, canes or physical therapy.

Advantages

Smaller operation
Smaller incision
Not as much bone removed
Shorter hospital stay
Shorter recovery period
Blood transfusion rarely required
Better movement in the knee
Feels more like a normal knee
Less need for physiotherapy
Able to be more active than after a total knee replacement

The big advantage is that if for some reason it is not successful or fails many years down the track it can be revised to a total knee replacement without difficulty.

Disadvantages

Not quite as reliable as a total knee replacement in taking away all pain Long term results not quite as good as total knee