The knee plays a pivotal role in day-to-day movement, with the patella itself being an under-appreciated part of the knee that is susceptible to damage. Here is a look at what the patella is, and what damage and injury can be associated with it.
What is the patella?
The patella is most commonly known as the kneecap. It’s an independent bone resting between the two leg bones, the femur (thighbone) and tibia (shinbone), covering the knee joint’s surface. The kneecap sits in a grove at the bottom of the femur, and tracks, or glides, within this groove during movement.
There is articular cartilage on both the femur and underside of the patella to provide some protection and cushioning around the kneecap, which itself is situated within the tendon of the quad muscles. The upper and lower leg bones are connected and supported by tendons and ligaments. The patella is crucial in everyday movements where the leg is moved, including straightening and bending at the knee.
What can go wrong?
A patella tracking disorder results when the kneecap moves out of its usual position during straightening or bending of the knee. It will often move forwards, but some individuals may experience it grinding towards the inside.
Patella tendinopathy, commonly referred to as Jumper’s Knee,
results from overuse of the patella tendon. This tendon transfers the impact of the quadriceps muscles, as your knee is straightened. Movements that involve jumping, bending and landing can strain these fibres and cause damage. Jumping, for instance, involves a sudden contraction of the quadriceps to straighten the knee as the body is lifting. These muscles then absorb some of the force of landing, with a slight bending of the knee. Repetitive jumping over time overuses the tendon and can result in inflammation or lesions which cause pain, discomfort and difficulties with mobilisation of the knee.
The patella can also break or fracture, either as a displaced, stable, open or comminuted fracture, at various points.
This is often the result of a forceful blow to the knee or even a fall directly onto the kneecap area. While less common but still possible, an immediate, forceful quadricep contraction can pull the patella apart.
is a sporting injury often found in athletes undertaking demanding movements, such as in football or basketball. Sudden directional changes, as well as jumping and landing repeatedly or incorrectly, can tear this ligament. The posterior cruciate ligament (PCL) can be damaged and torn when the knee is bent or receives a sharp blow to the front.
The patella can become displaced or dislocated, often due to accidents, such as road traffic crashes or other trauma, such as a fall. Poor tracking or displacement can result in pain, limited movement, stiffness, a sense of something slipping, or a popping or grinding sensation.
Tendon and meniscal tears can be a result of the ageing process, repetitive extreme movements and direct force to the front part of the knee.
How injuries can occur
Poor muscle tone, with weak quadriceps, can affect the movement of the patella and its placement, along with its ability to effectively track along the femoral groove. Ligaments that are too loose or too tight can negatively impact the ability of the patella to smoothly glide in place.
Repetitive, excessive sports and movements that involve the likes of jumping and twisting of the legs and knees, along with non-absorbent surfaces underfoot and inadequate footwear, can all increase the impact and strain on the knees and patella.
In some cases, structural abnormalities of the knee, joints or bones can result in dysfunction, such as misalignment of the patella within the femoral groove. Accidents, falls and trauma can affect the ligaments as well as the patella bone itself.
Complications can arise from injury to the patella. For instance, if the cushioning articular cartilage is damaged after a fracture, post-traumatic arthritis can result in stiffness in the knee and pain.
What are the treatments available?
is often recommended in the first instance, especially for low level, non-urgent damage. This involves rest, ice, compression and elevation of the knee and affected leg.
Anyone who notices pain, stiffness or swelling should seek medical attention. A doctor will assess the kneecap and joints, perhaps with the aid of further tests such as X-Rays, MRIs and CT scans. Depending on the outcome, they may recommend various possible treatments, including immobilisation, rest, a specialist referral, or physical therapy. The latter involves exercises specifically designed to strengthen and stretch the muscles and ligaments that support the knee, often alongside the guidance of a physiotherapist. A brace may be advised in tracking disorders to pull the kneecap back into place within the groove . Anti-Inflammatory medication and pain relief may also be suggested.
Fractures are often treated with a splint or brace to help immobilise and prevent further damage. If bones are displaced, however, surgery will generally be required.
Can injury be prevented?
Injuries associated with the patella can be prevented to some extent, generally through best practice when it comes to movement and exercise, and by following a few lifestyle tips. For instance, losing excess weight and avoiding excessive stress on the knee. In some cases, degenerative or inherited conditions may play a role, and a doctor will be able to offer suitable recommendations to help prevent further or possible future damage.