Anterior knee pain refers simply to pain in and around the front of the knee, which can be caused by several conditions. It is one of the most common knee symptoms and probably the condition clinicians fail to understand and fully assess. It is important that the clinician understands the various separate problems that can cause pain in the front of the knee, so that the correct tests can be undertaken to determine the cause of the patient’s pain.
Patients can have various symptoms such as a functional deficit, crepitus (crackling, popping sounds and sensations) or instability. Pain often gets worse with activities such as walking down stairs, squatting, driving, wearing high-heeled shoes or sitting for a long period of time with the knees bent. Patients can also experience a degree of instability, especially on walking up and down stairs or over ramps. Common causes of anterior knee pain can be:
Articular Cartilage Injury
When the articular cartilage of the knee joint (the smooth rubber-like padding that covers and protects the end of a bone at the joint) is affected and results in a tear. These lesions sometimes fail to heal in the knee joint and are associated with pain, loss of function and long-term complications such as osteoarthritis.
This condition occurs when the kneecap does not fuse properly after birth. Rather than forming one bone, the kneecap is two separate bones joined by a piece of fibrous tissue. The kneecap still functions properly, and baring any problems, the condition is not treated. Common in adolescence and usually without symptoms but can vary in severity and may sometimes need surgical treatment.
Inflammation of a bursa (a small sac of tissue) in the knee or below the kneecap.
The softening of the articular cartilage of the kneecap. This condition can cause anterior knee pain and can be associated with patellar misalignment.
Hyperextension and hyperflexion of the knee (movement of the joint and muscles that extend beyond the body's normal range of motion) which commonly occurs at the time of puberty.
Painful condition common in physically active adolescents and children. Symptoms include pain and swelling affecting the upper shin which are aggravated by jumping and kneeling along with sporting activities.
A form of knee osteoarthritis common among those in middle and older age.
Patellofemoral Pain Syndrome (PFPS)
Pain behind or around the kneecap. It is common in patients who are physically active and exercise regularly. It can be caused by weak muscles in the leg, joint hypermobility of the knee, feet problems, knee alignment problems and overuse when doing sporting activities.
Otherwise known as jumper's knee, this is a common and painful overuse disorder which is primarily a condition of 15 to 30 years old athletes, who participate in sports such as basketball, volleyball, athletic jump events, tennis, and football which require repetitive loading of the patellar tendon.
Misalignment of the kneecap often with damage to the patellofemoral joint.
Sinding Larsen Johansson Syndrome
A painful condition with inflammation of the bone at the bottom of the kneecap, where the tendon from the shin bone (tibia) attaches. It is an overuse knee injury rather than a traumatic injury and usually appears in adolescents and children during a growth spurt.