Whenever you move your knee, it crunches like a coffee grinder.
Does this sound familiar?
It could be a sign of patellofemoral osteoarthritis – the breakdown of cartilage on the underside of the patella (kneecap) and groove of the femur (thighbone).
“Degenerative changes behind the kneecap are the cause,” says German senior consultant orthopaedic surgeon Dr Sven Ostermeier, adding that the condition should be treated as early as possible, or ideally, prevented in the first place.
The kneecap does more than merely protect the knee joint.
“This disc-shaped bone in front of the knee is important (in conjunction with the quadriceps muscle on the front of the thigh) in extending and straightening the leg when you walk or stand,” he explains.
Whenever you bend or stretch your leg, the kneecap moves back and forth inside a groove on top of the thighbone.
Cartilage helps the bones glide smoothly against each other.
When cartilage wears away, the resulting friction can be painful, and even audible.
Many people aged 50 years or older have patellofemoral osteoarthritis, particularly those who are overweight, obese, or in occupations requiring heavy lifting, frequent kneeling or squatting.
This subjects knee joints to considerable stress, contributing to cartilage degeneration.
Joggers, too, can be affected.
The condition makes itself especially felt when descending stairs or inclines, according to Dr Ostermeier.
Standing up from a sitting position, kneeling or squatting can be painful as well.
Some people with the condition feel stiffness in the knee.
In some cases, the knee even seems to lock up when they try to move it.
If inflammation develops, there may be swelling and warmth in the kneecap region, notes Dr Ostermeier.
Early treatment is important, he says, to prevent the osteoarthritis from progressing to the entire knee joint.
Most cartilage damage behind the kneecap can be treated conservatively.
One thing that in many cases can relieve symptoms is losing excess body weight.
Strengthening the quadriceps – for instance, by doing knee bends – can also reduce strain on the knee, and stretching exercises that promote lateral mobility are good for the kneecap too.
But before starting exercises such as these, anyone with knee problems – including acute pain or inflamed joints – should first consult a medical specialist.
The doctor can provide advice on pain-relieving medications and further treatment options, such as cartilage cell transplantation or implants.
Here are three good exercises for your knees:
- Lie flat on your back with your legs stretched out on the floor.
Then lift one leg and draw your foot towards your buttocks. After several seconds, stretch your leg out again.
Do this a dozen times with each leg.
- Sit on a sturdy table and let your legs dangle.
This helps to distribute synovial fluid – a lubricant in freely-movable joints – over all of the cartilage surface in the knees.
The fluid reduces friction, and delivers oxygen and nutrients to cartilage, which doesn’t have its own blood supply.
- Stand on one leg and let the other swing back and forth about 10 times.
Do this three times with each leg. It will strengthen your leg muscles and improve balance.
You may need to rest a hand on the back of a chair for additional support the first few times you do this. – dpa
