Cartilage Injury/ Sick Cartilage/ Chondromalacia (sick cartilage) is an affliction of the hyaline cartilage coating of the articular surfaces of the bone. It results in the softening and then subsequent tearing, fissuring, and erosion of hyaline cartilage. Most commonly, it is recognized as involving the extensor mechanism of the knee and accordingly is often referred to as chondromalacia of the patella, patellofemoral syndrome, or runner’s knee. The undersurface of the patella is covered with hyaline cartilage that articulates with the hyaline cartilage covered femoral groove (trochlear groove). Post-traumatic injuries, microtrauma wear and tear, and iatrogenic injections of medication can lead to the development of chondromalacia. Chondromalacia occurs in any joint and is especially common in joints that have had trauma and deformities.[rx][rx][rx][rx][rx]
Causes of Cartilage Injury/ Sick Cartilage
In most patients with PFPS an examination of their history will highlight a precipitating event that caused the injury. Changes in activity patterns such as excessive increases in running mileage, repetitions such as running up steps and the addition of strength exercises that affect the patellofemoral joint are commonly associated with symptom onset. Excessively worn or poorly fitted footwear may be a contributing factor. To prevent recurrence the causal behaviour should be identified and managed correctly.
The medical cause of PFPS is thought to be increased pressure on the patellofemoral joint. There are several theorized mechanisms relating to how this increased pressure occurs:
- Trauma, especially a fracture (break) or dislocation of the kneecap
- An imbalance of the muscles around the knee (Some muscles are weaker than others.)
- Overuse (repeated bending or twisting) of the knee joint, especially during sports
- Poorly aligned muscles or bones near the knee joint
- Injury to a meniscus (C-shaped cartilage inside the knee joint)
- Rheumatoid arthritis or osteoarthritis
- An infection in the knee joint
- Repeated episodes of bleeding inside the knee joint
- Repeated injections of steroid drugs into the knee
- Increased levels of physical activity
- Malalignment of the patella as it moves through the femoral groove
- Quadriceps muscle imbalance
- Tight anatomical structures, e.g. retinaculum or iliotibial band.
Causes can also be a result of excessive genu valgum and the above-mentioned repetitive motions leading to abnormal lateral patellar tracking. Individuals with genu valgum have larger than normal Q-angles causing the weight-bearing line to fall lateral to the centre of the knee causing overstretching of the MCL and stressing the lateral meniscus and cartilages.
The cause of pain and dysfunction often results from either abnormal forces (e.g. increased pull of the lateral quadriceps retinaculum with acute or chronic lateral PF subluxation/dislocation) or prolonged repetitive compressive or shearing forces (running or jumping) on the PF joint. The result is synovial irritation and inflammation and subchondral bony changes in the distal femur or patella known as “bone bruises”. Secondary causes of PF Syndrome are fractures, internal knee derangement, osteoarthritis of the knee and bony tumors in or around the knee.
Symptoms of Chondromalacia/Cartilage Injury/ Sick Cartilage
The most common symptom of chondromalacia is a dull, aching pain in the front of your knee, behind your kneecap. This pain can get worse when you go up or downstairs. It also can flare up after you have been sitting in one position for a long time. For example, your knee may be painful and stiff when you stand up after watching a movie or after a long trip in a car or plane.
Chondromalacia also can make your knee joint “catch” meaning you suddenly have trouble moving it past a certain point, or “give way” (buckle unexpectedly). These symptoms tend to occur when you bend your knee repeatedly, especially when you go down stairs. In some cases, the painful knee also can appear puffy or swollen.
Chondromalacia can cause a creaky sound or grinding sensation when you move your knee. However, creaking sounds during bending do not always mean that cartilage is damaged.
Diagnosis of Chondromalacia
- Fractured your kneecap or any other bone in the knee joint
- Sprained your knee or injured your knee’s meniscus (the disk-shaped, shock-absorbing cartilage inside the knee)
- Had bleeding or an infection inside your knee joint
- Been diagnosed with arthritis in your knee
- Your doctor also will ask about the type of work you do and your recreational and sports activities.
- Patellar grind test or Clarke’s sign – This test detects the presence of patellofemoral joint disorder. A positive sign on this test is pain in the patellofemoral joint.
- Compression test
- Extension-resistance test – This test is used to perform a maximal provocation on the muscle-tendon mechanism of the extensor muscles and is positive when the affected knee demonstrates less power when trying to maintain the pressure.
- The critical test – This is done with the patient in high sitting and performing isometric quadriceps contractions at 5 different angles (0°, 30°, 60°, 90° and 120°) while the femur is externally rotated, sustaining the contractions for 10 seconds. If pain is produced then the leg is positioned in full extension. In this position, the patella and femur have no more contact. The lower leg of the patient is supported by the therapist so the quadriceps can be fully relaxed. When the quadriceps is relaxed, the therapist is able to glide the patella medially. This glide is maintained while the isometric contractions are again performed. If this reduces the pain and the pain is patellofemoral in origin, there is a high chance of a favourable outcome.
Anterior knee pain is the most common chief complaint of patients with chondromalacia. This pain is usually made worse with activities that increase the stress on the patellofemoral joint, for example, stair climbing, squatting, and running. Differential diagnoses for anterior knee pain include Hoffa disease, osteochondritis dessicans of the patellofemoral joint, patellar tendonitis, patella alta, patella Baja, patella instability, plica, and bi-partite patella.
The history should include an evaluation of previous trauma, co-morbid conditions, unstable joints, foot and ankle pain or dysfunction, and activity. Likewise, the physical exam should appraise quadriceps appearance, the orientation of foot and ankle, as well a specific evaluation of the patellofemoral joint.
Specific evaluation of the patellofemoral joint should include assessment of pain, effusion, quadriceps strength, patella mobility, and crepitance. The physical examination test which specifically evaluates the knee for chondromalacia is Clark’s test. This test evaluates patellofemoral grinding and pain by compressing the patella into the femoral trochlea and having the patient contract their quadriceps muscle-pulling the patella through the groove.
X-ray examination of the knee allows for assessment of patella anatomy and positioning in the knee, and MRI allows for additional assessment of articular cartilage water content and wear.
Treatment of Chondromalacia
Your doctor probably will recommend nonsurgical treatments first. These include:
- Applying ice after exercise and as needed for pain or swelling
- Taking a nonsteroidal anti-inflammatory drug, such as ibuprofen (Advil, Motrin and others), to relieve your knee pain and ease any swelling
- Taking other pain relievers, such as acetaminophen (Tylenol), which may also relieve pain
- Starting an exercise program to strengthen the muscles around your knee
- Avoiding high-impact exercises
- Avoiding all kneeling and squatting
- Using knee tape, a brace or a special patellar-tracking sleeve to keep your kneecap aligned properly
In the absence of cartilage damage, pain at the front of the knee due to overuse can be managed with a combination of RICE (rest, ice, compression, elevation), anti-inflammatory medications, and physiotherapy.
Management of the patient with chondromalacia is difficult, and there is no one specific form of treatment that is universally accepted as a standard of care. Medical management should be based on the physical exam findings and can include patella stabilizing braces, physical therapy for quadriceps strengthening, orthotics which decrease pronation of the foot, and nonsteroidal anti-inflammatory medication. The use of platelet-rich plasma (PRP) is sometimes advocated, but it is not the standard of care. PRP has not been shown to improve patient outcomes consistently. Likewise, prolotherapy has been recommended by some authors, but it is not the standard of care and has not been shown to improve patient outcomes consistently.
Physical therapy focusing on strengthening the quadriceps, hamstrings, adductors, and abductors can help improve your muscle strength and balance. Muscle balance will help prevent knee misalignment.
Typically recommended are non-weight-bearing exercises, such as swimming or riding a stationary bike. Additionally, isometric exercises that involve tightening and releasing your muscles can help to maintain muscle mass.
Surgical management is indicated when there is a failure to respond to medical management. Arthroscopic evaluation and subsequent debridement of diseased cartilage (chondro abrasion), plica releases, or lateral retinacular releases are frequently the first-line of surgical management. Sometimes, open re-alignment procedures are used to improve patellofemoral tracking. The option for patellofemoral replacement arthroplasty is available but rarely used.
Arthroscopic surgery may be necessary to examine the joint and determine whether there’s the misalignment of the knee. This surgery involves inserting a camera into your joint through a tiny incision. A surgical procedure may fix the problem. One common procedure is a lateral release. This operation involves cutting some of your ligaments to release tension and allow for more movement.
You may be able to reduce your risk of chondromalacia by preventing knee injuries and overuse of your knee joints. To do this:
- Warm up and stretch before you participate in athletic activities.
- Do exercises to strengthen the leg muscles around your knee, especially the muscles in your thigh called the quadriceps.
- Increase the intensity of your training program gradually. Never push yourself too hard, too fast.
- Wear comfortable, supportive shoes that fit your feet and your sport. Problems with foot alignment can increase your risk of knee injuries. Ask your doctor about shoe inserts that can correct alignment problems.
- If you ski or if you play football or soccer, ask your doctor or trainer about specific equipment that can help to reduce your risk of knee injuries.
- If you often kneel on hard surfaces when you work, wear protective knee pads.
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