Background and Etiology
The knee is the largest joint in the body. It is built for weight bearing, stability and mobility. The knee complex is composed of four bones: the femur, tibia, fibula and the patella (kneecap). There are also three osseous bone-to-bone joints: the patellafemoral joint, tibiofemoral joint and the tibiofibular joint. The patella (kneecap) is a sesamoid bone, which means it is a bone that is imbedded or located inside a tendon. In the case of the patella it is imbedded in the quadriceps tendon. The two most common conditions that affect the patella are patellofemoral pain syndrome and chondromalacia pain syndrome.
Function of the Patella
- Protects the front of the knee joint.
- Acts as a fulcrum to provide leverage, thus allowing the quadriceps tendon to function more efficiently and produce greater force when straightening the knee.
- The patella glides up and down in a groove formed between the two condyles of the femur (leg) bone.
Chondromalacia is the softening or breakdown of cartilage on the undersurface of the patella. Cartilage is a smooth shiny surface on the patella that allows it to slide freely over the femur. Common causes include:
- Softening or breakdown of the cartilage can be due to joint degeneration, wear and tear or arthritis.
- Poor tracking of the patella on the femur can result in wearing on the undersurface of the patella that causes chondromalacia.
- A sharp blow to the patella can result in damage to the undersurface of the patella.
- Knee pain at the patella especially when squatting, kneeling, running and when taking stairs (especially going down.)
- A sudden feeling of the knee giving way or buckling.
- A feeling of catching, crackling, grinding or sandpaper underneath the knee cap.
- Swelling of the knee joint.
- Pain with sitting for extended periods of time or when getting up from a sitting position.
- Swelling may be present at or along the patella
- Restriction or limitation in patella movement.
- A medical evaluation that includes a good medical history and a clinical exam that uses several special tests can often be used to diagnose chondromalacia.
- X-rays can be used visualize the position of the patella in the femoral groove.
- Initial treatment of chondromalacia would include avoidance of the activities that produce pain or stress the patella (jumping, running, kneeling, stairs and squatting).
- The use of ice to reduce inflammation and pain.
- NSAIDS (nonsteroidal anti-inflammatory drugs)
- Physical Therapy
- The use of a knee brace to stabilize the patella.
- The use of patella taping to improve the tracking and alignment of the knee cap during activity and exercise.
- Surgery may be indicated in extreme cases to release the tight structures of the outside of the knee (lateral retinaculum). This procedure is called a lateral release.
Physical Therapy Interventions
Physical Therapists are professionals, educated and trained to administer interventions. As defined by The Guide to Physical Therapist Practice, interventions are the skilled and purposeful use of physical therapy methods and techniques to produce changes consistent with the diagnosis, prognosis and the patient or client’s goals.
Physical therapy for chondromalacia must remain conservative at the onset to avoid aggravating the condition. Emphasis will be on rest, reducing the inflammation and avoiding activities that aggravate the condition. Once the initial inflammation has been reduced, an aggressive program of site specific stretching and strengthening will be initiated to restore normal patella tracking and stabilize the patella as it glides over the femur.
Physical Therapy Interventions
Common physical therapy interventions for this condition include:
- Manual Therapeutic Technique (MTT): hands on care including soft tissue massage, stretching and joint mobilization by a physical therapist to improve patella movement, and reduce tightness of the lateral knee tissues to improve patella tracking. Use of mobilization techniques can also help to modulate pain.
- Therapeutic Exercises (TE): including stretching and strengthening exercises to regain range of motion and strengthen muscles of the knee to support, stabilize the patella. The exercise program is designed to improve tracking of the patella in the femoral groove. In most cases the emphasis is on the medial quadriceps muscles and hip musculature.
- Neuromuscular Reeducation (NMR) to restore stability, retrain the lower extremity and improve movement techniques and mechanics (for example, running, kneeling, squatting and jumping) of the involved lower extremity to reduce stress on the patellofemoral joint in daily activities. Patella taping can be used to improve the alignment and tracking of the knee cap during activity and exercise.
- Modalities including the use of ultrasound, electrical stimulation, ice, cold, laser and others to decrease pain and inflammation of the involved structures of the knee.
- Home programs: including strengthening, stretching and stabilization exercises and instructions to help the person perform daily tasks and advance to the next functional level.
Avoiding the activities that produce the pain or stress the involved bursa is the first line of treatment.
- RICE: Rest, Ice, Compression and Elevation should be used to reduce the stress on the bursa.
- NSAIDS (non steroidal anti-inflammatory drugs) to reduce pain and inflammation.
- Use of a knee support to stabilize and improve tracking of the patella
- In cases that are not responsive to conservative measures surgery may be indicated to release the lateral structures of the patella. This will help realign the patella in the femoral groove.
In general, patients respond well to conservative treatment of chondromalacia. It is important that once the pain and inflammation is reduced and patella tracking and strength are restored that the patient gradually returns back to full activities. Instruction in daily activities or sport performance is helpful to reduce the chance of a reoccurrence of this condition. In most cases full return to activity will take from 4-6 weeks depending on the severity of the condition. Following surgical intervention like a lateral release it may take 6-8 weeks to return to full function. As a preventive measure individuals should:
- Make modifications in work or daily activities like avoiding kneeling and squatting, or wearing protective equipment to avoid prolonged pressure or unexpected blows on the patella.
- Maintain strength and flexibility to reduce stress on the patella or create imbalances in patella tracking.
- Avoid highly repetitive activities whenever possible.