Young for Total Knee Replacement

Curiously enough, high age is no obstacle for a total knee replacement, but low age is!

Studies demonstrated that:

• only 25% surgeons were against total knee replacement operations in patients aged over 80 years, whereas
• 65% surgeons were against total knee operations in patients younger than 50 years

Why?

Here are some answers:
1) Total knees fail more often in young patients
Many studies demonstrate that total knee prostheses in young patients fail more often than do the prostheses in older patients, but the results of different studies may be difficult to compare. This Table is derived from material published by The Swedish Knee Arthroplasty Register and presents failure rates observed during the first ten years after a total knee replacement operation for osteoarthritis of the knee.

(Robertsson, Thesis Lund 2000)

2) Young patients wear away their total joints more
than their older colleagues. Wear of bearing surfaces in artificial joints is dependent on the amount of movements in the joint. The more you are walking on your total hip / knee joint the more you wear away the joint surfaces. ( It is about the same phenomenon as wearing off the tires – the more you drive your car, the more you wear the tires). In the polyethylene-on-metal joint it is the softer polyethylene that wears away.

This table demonstrates that “young” patients after THR and TKR walk on average up to 50% more than the “older” patients and wear correspondingly more their joint surfaces. The more of the polyethylene surfaces transforms in fine dust particles the greater the risk that the patient will develop osteolysis (bone dissolving disease). Osteolysis is the most frequent cause of total hip / knee joint failure. (Zahri, 1998)

3) Young people live longer

Young people are not only more active, they will also be living longer. The Table demonstrates that young people have much better chances to live till their total hip / knee fails. The young people “survive” their prosthesis. Older people, on the other hand, die sooner before their total hips / knees have chance to fail.

Together, these three Tables demonstrate that there is much higher risk that a young patient will return to his / her surgeon with a failed total knee during the next 10 years after the surgery then for an aged patient.
The surgeons know well these facts. Moreover, the surgeons also know that the second operation (revision operation ) of the total knee will be technically more difficult and the result not so good as with the first total knee operation.

There are, however, arguments in favor of total joint replacements in young patients.
The surgeon may carry out a total knee operation with a total knee prosthesis that wears out more slowly. There are many such total knee prostheses on the market, although for many of them there is no long track evidence that they really deliver what the manufacturer promises.
About 40% of all surgeons operate on patients < 50 years, if the pain and disability in their knees warrants the surgery. (Mancuso 1996)

In the past, reduction of pain was the primary reason for the total knee replacement.

Modern patients, however, expect to have more improved function in their legs after the total knee replacement operation. The improved function includes not only activities of daily living but also athletic activities.

Young patients will not understand that the young age should be a hinder to achieve these goals. The young patients, however, must be learned that the increased activity produces increased wear of the total joint prosthesis. They must be learned also how to avoid the wrong use of their total knees during their sport activity.

Modern surgeons now believe that

• as long as the patients understand the increased risks associated with recreational / athletic activity after total knee replacement and
• as long as they are specially training to diminish these risk, there is no reason to discourage the young patients from having a total knee replacement surgery. (Healy 2001)

MORE QUESTIONS FROM THE YOUNG PATIENTS

Who is considered a young patient?

Usually patients younger than 50 years of age, and patients with life expectancy of greater than 20 years and with a family history of longevity.

Are the knee joint diseases in young patients different?

Yes.
In young patients operated on with total knee arthroplasty prevails rheumatoid arthritis and posttraumatic damages of the knee joint

for older patients (> 55 years) prevails osteoarthritis.

When is the young patient a candidate for a total knee replacement?

The indications for operation of young patients with a total knee replacement do not differ from indications for older patients. These are:

• severe pain and stiffness in the knee joint,
• impaired quality of life,
• failure of previous treatments of the painful hip / knee joint.
• specially suitable candidate is a young patient with severe impairment of both hip and knee joints

What are the results of total Knee replacement in the young patients?

This question has no simple answer, because the results of total knee replacement in young patients depend on several factors, such as the type of the patient’s knee disease, the type of total knee prosthesis used, the length of the observation (follow up time), and many others.

Alternative operations

Are there other / alternative knee operations for the young patients?

Yes, but these operations are most useful in certain patients only.

Who are the candidates for these alternative operations?

In general, patients with only partly damaged knee joint surfaces and still retained motion in their knees are candidates for the alternative operations.

Knee joints with grossly destructed joint surfaces and severe stiffness, on the other hand, usually cannot be helped with these alternative operations.

For more information visit the chapter Alternative knee operations.

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References:

1. Mancuso et al. Indications for Total Hip and Total Knee Arhroplasties. J Arthroplasty, 1996, 11, 34 – 46)
2. Healy WL et al. Athletic Activity after Joint Replacement. Am Journal Sports Medicine; 2001, 29: 377 – 88
3. Robertsson O. The Swedisk Knee Arthroplasty Register. Thesis, Lund 2010.
4. Zahri CA et al. Assessing activity in joint replacement patients. J Arthroplasty, 1998,13, 890-95.