Bursae are small sacks of fluid which lie between a tendon or muscle and the underlying bone. Their purpose is to reduce friction between the two. There are approximately 160 bursae in the body.
Bursitis is the inflammation of one of these sacks of fluid. It can occur either as an overuse injury, or due to a direct impact. Bursitis as an overuse condition occurs due to repeated rubbing of the overlying soft tissue. Impact bursitis is due to bleeding into the bursa.
Common sites of Bursitis:
- Trochanteric bursitis
- Ischiogluteal bursitis
- Achilles (retrocalcaneal) bursitis
- Subacromial bursitis
- Infrapatella bursitis
- Pes Anserine bursitis
- Pre-patella bursitis (housemaids knee)
- Olecranon bursitis (students elbow)
What are the Symptoms?
In cases of impact bursitis, a large, swollen, tender area will area soon after impact.
Symptoms of overuse bursitis are less defined. There is usually a swollen area, although less defined than with an impact injury. There will be pain on movement which involves contraction of the overlying muscle (or tendon - e.g. the achilles tendon). The bursa will be tender to touch (if possible). It is sometimes difficult to distinguish between bursitis and injury to the overlying tendon, without an MRI scan.
How is Bursitis Treated?
Impact bursitis should be iced and a compression bandage applied. If swelling doesn't decrease naturally, the bursa may need to be aspirated (the fluid is drained using a needle).
Overuse bursitis injuries are more difficult to treat. Rest from any aggravating activities and the use of anti-inflammatory medication is usually recommended. Occasionally the bursa may need to be aspirated, or a corticosteroid injection may be required.
If the bursa is thought to be caused by any biomechanical, postural or muscular imbalances then these should be addressed before returning to activity.