Bursitis can be a painful condition, especially when located in the weight bearing knee joint. Since the job of the bursa is to cushion and lubricate the joint where friction is likely to occur, inflammation will result in pain in most weight bearing, flexion, or extension activities. The knee joint has on average fourteen busae.
Anatomy and physiology
A bursa is a sac filled with a viscid fluid. The deep bursa formed by the joint capsule at the knee, the suprapatellar bursa, is the largest bursa in the body. It is located between the femur and quadriceps femoris tendon. Three other major bursae of the knee are the subcutaneous prepatellar bursa, located between the skin and the anterior surface of the patella, the superficial infrapatellar bursa, located between the skin and the patellar (tendon) ligament, and the deep infrapatellar bursa, located between the tibial tuberosity and the patellar (tendon) ligament. Finally, the pes anserinus bursa is located at the lower inside of the knee joint where sartoris, gracillis, and semitendinosus insert as the conjoined pes anserinus tendon. The prepatellar bursa is the most commonly injured due to its superficial location. Repetitive kneeling or impact to the knee cap can damage this bursa. The infrapatellar bursae are most commonly inflamed during jumping and landing from repetitive friction of the patellar (tendon) ligament. The pes anserinus bursa is less commonly involved in injuries but can result from load bearing on the inside of the knee, as seen with improper gait or use of worn or improperly sized running shoes.
Cause of Knee Bursitis
Repetitive presssure of trauma to the bursa. Repetitive friction between the bursa and tendon or bone.
Signs and symptoms
Pain and tenderness. Mild swelling, due to relapse of the fluid in the bursal sac. Pain and stiffness when kneeling or walking downstairs.
Complications if left unattended
If a bursa is allowed to rupture and release its fluid, the natural cushioning will be lost. The build-up of fluid will cause loss of mobility in the joint as well.
- Anti-inflammatory medication
Rehabilitation and prevention
Strengthening the muscles around the knee will help to support the joint, and increasing flexibility also will relieve some of the pressure exerted by the tendons upon the bursa. Frequent rests when required to be in a kneeling or crouching position also help to prevent this condition. Identifying any underlying problems, such as improper equipment or form is important during rehabilitation to prevent it from recurring.
Bursitis is seldom a long-term concern if treated properly. Occasionally draining of the fluid from the joint is necessary.