What is it?
The patellofemoral joint is a common site of pain. The diagnosis of chondromalacia patellae shows a beginning with visible cartilage alterations and eventually leading to patellofemoral arthritis. Chondromalacia may begin at any age and is commonly found in adolescents.
Retropatellar cartilage breakdown is the hallmark of chondromalacia. Chondromalacia progresses in different stages. First, stage one begins with cartilaginous swelling and softening. Stage two has partial thickness fissuring and stage three has full-thickness fasciculations. Next, stage four is where you see cartilage destruction with exposure to subchondral bone. Stage four chondromalacia represents the onset of degenerative joint disease and is distinguishable from that disorder.
Imbalanced actions of the static and dynamic knee stabilizers can alter the distribution of forces to the patellofemoral articular surface and related soft tissues. These biomechanical tracking stressors are compounded through activities of daily living, causing irritation and eventually wear to the patellofemoral cartilage.
Any factor that alters normal patellofemoral mechanics is a risk factor for chondromalacia patellae. This includes lateral tracking disorders, tightness in the lateral knee capsule, weakness of the vastus medialis or quadriceps, pes planus, hip abductor weakness, joint overloads/ overuse, trauma, patellar hypermobility, and muscle imbalance. Additionally, risk factors for the development of CMP include obesity, hypermobility, instability, prior cruciate ligament (ACL, LCL) injury, and prior trauma, fracture, or patellar subluxation.
Clinical Presentation
Symptoms include dull peripatellar pain that is exacerbated by activities that load the joint, including prolonged running, squatting, kneeling, jumping, arising from a seated position, or stair climbing. Disruption of patellofemoral cartilage may result in crepitance, intermittent locking, or giving out (losing feeling).
Clinical evaluation of CMP should be directed toward identifying factors that create an imbalanced force on the patella. Palpation generally reveals peripatellar tenderness with the exacerbation of symptoms upon patellar compression.
Diagnosis
Knee radiographs may be necessary to rule out fractures in those with a history of trauma or osteoarthritis and in patients older than 50. Radiographs may also be appropriate in patients with significant swelling, a recent history of knee surgery, and those whose pain does not improve with a trial of treatment.
MRI is the modality best suited to identify cartilage lesions. Clinicians should recognize that cartilage lesions are exceptionally prevalent in symptomatic patients
Management
Management of CMP should progress from minimization of aggravating factors and anti-inflammatory measures to long-term correction of functional deficits. Lifestyle modification may be necessary to reduce pain-provoking activities, especially running, jumping, and activities that induce valgus stress.
Myofascial release and stretching should be directed at hypertonic muscles, including the FTL, calf muscles, hamstrings, piriformis, and psoas. Myofascial release or IASTM may be appropriate for tightness in the IT Band, posterior hip capsule, and lateral side of the knee. Manipulation may be necessary for restrictions in the lumbosacral and lower extremity joints.
Glute and VMO weakness are key factors in the development of knee pain, strengthening exercises are generally necessary for those muscles. Eccentric quadriceps strengthening is more effective than concentric exercise in the treatment of knee pain.
A surgical “lateral release” of the lateral retinaculum is the last resort when conservative care measures have failed.