Chondromalacia Patella (CP): This refers to degeneration and damage of the articular cartilage covering the underside of the patella. The degree of CP can vary from mild "softening" of the cartilage to complete loss of articular cartilage, exposure of the bone on the undersurface of the patella, or of the groove where the patella glides (femoral trochlea). This may result from old age, a previous injury, or from an accumulation of wear and tear.
PFPS: CP and femoral trochlea articular cartilage degeneration can also collectively be called patellofemoral osteoarthritis (PF OA). Patellofemoral pain syndrome (PFPS) describes patellar knee pain that is not due to tendinosis, CP or PF OA. PFPS is considered to be a functional problem related to muscular imbalances of the hip and quadriceps muscles, which leads to the patella tracking incorrectly--causing anterior knee pain.
For patellar tendon pain, one will usually notice localized pain at the bottom or top of the knee. If you have CP or PFOA your pain will likely be behind or underneath the knee.
With CP and PF OA, there can be an associated feeling of painful grinding behind the patella and even knee swelling. For those with PFPS, the pain is usually more generalized around the entire patella. For all these conditions, there can be pain during riding, but especially when more force is directed through the knee, such as when riding in a high gear, up inclines, sprinting or when riding while standing.
There can also be pain with deep squatting, kneeling and after sitting for prolonged periods of time when the knee is in a flexed position. With patellar tendonitis and PFPS, x-rays are usually normal but may show bone spurs at the insertion points of the quadriceps and patellar tendon.
Depending on the severity of CP and PF OA, x-rays may show decreased patellofemoral joint space, bone spurs, thickening and cysts. Depending on severity of patellar tendonitis, diagnostic ultrasound may show degenerative changes that include hypoechoic regions, tendon thickening and calcific deposits. MRI is generally not required for diagnosis.
The recommendations for the initial conservative management of all knee pain are generally the same. These include:
1. Modify your training. Training intensity and volume should be decreased to a level that does not cause the reproduction of one's symptoms. Riding in lower gears at high RPMs and avoiding riding while standing will decrease the force transferred through the knees.
2. Adjust your position on the bike. Increasing the height of the bicycle seat and pushing the bicycle seat back may help to reduce stress on the knee joint and the extensor mechanism causing knee pain. Adjust in small increments. If that doesn't work, consider a bike fit.
3. Start taking medication for inflammation. NSAIDs can be taken orally or applied topically to reduce knee inflammation, pain and swelling symptoms. Ibuprofen must be taken consistently to decrease symptoms.
4. Strengthen the muscles around the knee. Progressive strengthening exercises of the quadriceps, specifically of the inner quads (vastus medialis) should be started. Quadriceps strengthening exercises include:
1. Leg extensions
2. Leg press
As one's symptoms improve, the strengthening exercises should be performed with each leg individually. Adding and/or emphasizing the eccentric phase (lengthening) of quadriceps strengthening may be more beneficial for management of tendinosis compared to just doing concentric (contraction phase) strengthening for the management of many tendinopathies.
Eccentric strengthening refers to muscle contraction while the muscle fibers are lengthening. Eccentric strengthening exercises for the quadriceps includes:
1. Drop squats
4. Concentration on lowering the weight slowly while doing a leg extension.
Strengthening exercises should be done with lower resistance and higher repetitions.
In addition to the quadriceps, strengthening of the hip, gluteal external rotation muscles, abductor muscles and the iliotibial band may help improved one's knee symptoms. Maintaining flexibility of the gluteal, hamstring, quadriceps and calf muscles should be maintained and improved with stretching, foam rolling, massage therapy and yoga.
5. Try knee bracing. For CP, PF OA, and PFPS, wearing a patella bracing may help promote more optimal patellar tracking.
6. Try an alternative treatment. If quadriceps strengthening, stretching exercises, NSAID medication and bracing do not adequately improve symptoms, less studied treatment options might be an option. These include nitroglycerin patching, extra-corporeal shock-wave therapy and platelet-rich plasma injections. For CP and PF OA, intra-articular corticosteroid and viscosupplementation injections.
7. Consider a surgical option as a last resort. Surgical approaches for management of chronic tendinopathy and CP and PF OA include open and/or arthroscopic debridement. Surgery should always be a last resort.
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Dr. Victor Lun, MSc., MD, CCFP, Dip. Sport Med is a Sport Medicine physician who practices at the University of Calgary Sport Medicine Centre. He is the team physician for several winter and summer sport Canadian national sport teams.