Anterior Knee Pain (Chondromalacia Patellae)
What is a Anterior Knee Pain?
Anterior knee pain also known as “patellofemoral pain syndrome” or “chondromalacia patellae” refers to pain arising from the front part of the knee. This occurs when there is an overload on the joint between the back of the knee cap (patella) and the front of the femur (trochlea groove). As the knee bends and then straightens, the patella glides over the groove at the front of the femur (trochlea groove). Normally the movement of the patella in this groove is smooth and painless. Abnormal movement of the patella in the trochlea groove causes an overload on the patella with resultant pain. Long-term persistent abnormal movement and abnormal load can lead to degeneration in the joint between the patella and the trochlea groove leading to osteoarthritis.
Causes
Some patients develop patellofemoral pain syndrome in the absence of any bone, joint or soft tissue abnormalities. However, most patients with the syndrome present with one or more abnormalities related to bone anatomy, joint anatomy and/or soft tissue.
Symptoms of Anterior Knee Pain
Patients with patellofemoral pain may experience:
Treatment options
In an acute episode of anterior knee pain, the treatment is initially based on the RICE principles: rest, ice, compression and elevation. Crutches may be required for a few days to allow for the pain and selling to subside. As soon as symptoms allow a rehabilitation program under the guidance of a physiotherapist is required.
The aims of physiotherapy are to reduce swelling, restore normal joint motion, restore strength of quadriceps muscle, especially its main inner portion, the vastus medialis oblique (VMO) muscle. The physiotherapist may also recommend stretching exercises of hamstring muscles and the iliotibial band. Occasionally taping of the patella into place may help relieve or reduce the chance of ongoing symptoms. In a few patients, particularly patients that experience anterior knee pain after knee trauma this may be all that is required to address the symptoms and allow return to full function.
Most patients that experience recurrence of symptoms with minimal or no trauma require investigations to assess for abnormalities predisposing to patellofemoral pain syndrome. Depending on symptoms, abnormalities identified and status of articular cartilage on the patella and trochlea groove surgical intervention may be required. The surgical procedures used to treat patellofemoral pain syndrome may include one or more of the following:
Bone realignment (osteotomy)
Correction of knocked knee deformity.
Correction of abnormally twisted femur.
Correction of laterally positioned tibial tubercle.
Correction of high riding patella (patella alta).
Procedures to decrease the stress across the patellofemoral joint.
Soft tissue reconstruction (medial patellofemoral ligament)
Isolated knee arthroscopy with smoothening of the articular cartilage or lateral release has not shown any long-term benefit in numerous clinical studies and is not recommended. Dr Razvan Stoita will discuss with you at length the factors responsible for your symptoms and the recommended treatment.
Frequently Asked Questions (FAQ)
In a total knee replacement, the entire knee joint surface is replaced – the ends of the femur (thigh bone), tibia (shin bone), and usually the underside of the kneecap are all resurfaced with artificial components. In a partial knee replacement (PKR), also called unicompartmental knee replacement, only the damaged compartment of the knee is replaced, leaving healthy bone, cartilage, and ligaments intact.
Diagnosis involves understanding a history of your symptoms, examining your knee, and using imaging such as X-rays to assess cartilage wear and joint alignment. In some cases, additional scans such as CT or MRI scans may be required to either exclude other conditions or quantify the degree of arthritis.Some patients develop patellofemoral pain syndrome in the absence of any bone, joint or soft tissue abnormalities. However, most patients with the syndrome present with one or more abnormalities related to bone anatomy, joint anatomy and/or soft tissue.
Although knee arthritis can affect anyone, there are several factors that can increase the risk of arthritis:
- Genetic predisposition
- Previous knee injury or surgery
- Other joint conditions such as rheumatoid arthritis or gout
- Occupations involving heavy manual work
- Age (over 40)
- Female gender
- Being overweight or obese
- Participation in high impact activities or sports (e.g. running, soccer or rugby)
Knee arthritis typically develops as a result of progressive cartilage wear within the joint. This process may occur naturally with age or be accelerated by factors such as previous injury, altered joint alignment, or increased mechanical load.
In some cases, inflammatory conditions such as rheumatoid arthritis can also contribute to joint degeneration.
