The patella or kneecap is one of three bones, along with the shin bone of leg and thigh bone, which make up the knee joint. All of these bones are covered with a layer of cartilage at points where their surfaces come into contact. This lining helps frictionless smooth gliding movement between the bones. Furthermore, the patella is wrapped up inside a tendon. This tendon connects the muscle of the thigh to the shin bone below the knee joint.
The patella is important functionally because it increases the leverage of the knee joint. Patella transmits enormous amounts of stresses during this leverage which can affect its lining. The most common symptom of patellar irritation is pain associated with prolonged sitting and descending stairs. The reason the pain is more severe when descending stairs rather than climbing is due to the mechanics of the knee joint. The basic explanation is that the force burdened by the patella is about two times body weight when climbing up stairs, and seven times body weight when descending. This increased burden on the kneecap when going downstairs causes a magnification of pain during that activity.
Types of Knee Cap or Patella Injuries
Chondromalacia Patellae (Runner’s Knee): The most common disorder is known as chondromalacia patellae, often called Runner’s Knee. Chondromalacia occurs because of irritation of the articular cartilage on the undersurface of the kneecap. Chondromalacia is often seen in cases of arthritis.
Prepatellar Bursitis (Housemaid’s Knee): Prepatellar bursitis, or Housemaid’s Knee Syndrome, is a condition of swelling and inflammation over the front of the knee. This is commonly seen in patients who kneel for extended periods, and also after minor but direct injuries on knee cap which may lead to the collection of blood/fluid under the skin over the kneecap.
Patellar Subluxation/Dislocation: Also called an unstable kneecap, patients who experience this painful knee condition have a patella that does not track evenly within its groove on the femur. If it is going out of its track surgical correction is necessary.
Patellar Tendonitis (Tendonitis of the Knee Cap): Patellar tendonitis occurs when the tendon and surrounding tissue become irritated and inflamed. This is common in athletes who jump but can also be seen in other athletes. The pain is normally centralized over the tendon and there may be some swelling around the tendon.
Dull pain aggravated with prolonged sitting with a bent knee, squatting on the floor, on stairs, walking on slopes, and activities like jogging/running. Another important symptom is pseudo instability. The knee may buckle or “give way” when you walk but there would not be any actual ligament problem. This is due to sudden pain in front of the knee, the thigh muscle stops supporting the knee for a moment. You may experience tenderness, swelling, and bruising around the joint. A dislocated knee cap is very obvious with deformity and pain.
Osteoarthritis or just the wear and tear of normal aging can soften cartilage under the kneecap. In addition, some people are born with slightly misaligned bones, imbalanced quadriceps muscles, or shallow patella femoral grooves that increase the chances of cartilage damage or knee dislocation. This is more common in young people especially in women and in athletes. Chondromalacia of knee cap is due to these causes but in many, the exact cause is difficult to ascertain. A patellar dislocation can also occur when a person twists his knee, changes direction, or suffers a direct blow to the knee while playing sports.
Proper symptomatic description by the patient may suggest the kneecap problems. X-ray and in certain cases MRI scan also help in diagnosis.
Treatment of these various kneecap conditions depends on the diagnosis. But there are some general guidelines that can be followed. In acute cases, rest and pain medication followed by physiotherapy and in long-standing cases appropriate tests to find out the cause will help in the treatment. Even long-term knee pain cases initially will be managed conservatively, but surgery may be necessary for some.
Healthy Joint Club says:
Many cases of knee cap problems can make life miserable as it may get difficult even to negotiate a small step without the fear of a fall, or a catching sensation. But many cases of Chondromalacia from late teens the to early thirties can be managed adequately with treatment. Complete relief of pain may be not possible in all cases but enough relief can be obtained in most patients to be able to manage normal daily activities. One doesn’t need to worry about ‘Catching’ arthritis, though the same symptoms from mid-thirties might indicate the onset of osteoarthritis in the knee especially in obese individuals. Simple lifestyle changes with stress on exercise and diet changes would go a long way in helping these patients.