Bursitis and tendinitis are two conditions that fall into the list of differential diagnoses for acute joint pain. A little background in human anatomy is necessary to understand the differences between these two conditions.
Bursae are fibrous sacs filled with synovial fluid. There are bursae around almost all joints in the body. Bursae are limited by a strong fibrous cover and are lined by synovium. The fluid inside the bursa makes a thin film. Bursae provide protection against friction between muscles, tendons and bones. Bursae make the movements at joints much easier.
Bursitis is the inflammation of the bursae. These bursae can get inflamed following injury. Injury may be due to a powerful acute force or due to wear and tear. Small injuries inside the synovium release inflammatory mediators, which trigger an acute inflammatory reaction. The bursae swell up with edema fluid. Presenting features of bursitis are pain at joint, limited movements, and a well-defined swelling. In many cases, the complete joint is not inflamed. Most common sites of bursa inflammation are elbow, first tarso-metatarsal joint, heels and knees. Features of acute inflammation are always there. Redness, pain, swelling, heat and poor functionality are the key features of bursitis.
Investigations include joint X-ray, ESR, CRP, rheumatoid factor, ANA, DsDNA, antiphospholipid antibodies, full blood count and renal function tests. Bursitis may not show overt changes in investigations and the joint X-rays are almost always normal. Rest, heat therapy, physiotherapy, analgesics and anti-inflammatory drugs are the usual modes of treatment for bursitis.
Muscles that we can move at will are called skeletal muscles. They are under voluntary control, and they are the ones we need, to make gross and fine movements. A skeletal muscle has two tendons at either end with a body in the middle. Tendons attach the muscle on to bones. Tendons are very strong fibrous bands made up mostly of a fiber called collagen. There are prominently visible tendons just above the heels, just below knee caps, behind knees and at the elbows. Tendons become prominent when we contract the relevant muscles. The most famous tendon in the body may be the Achilles tendon located and felt like a thick strong cord just above the heels at the back of the lower legs.
These tendons get inflamed most commonly following trauma. Patients having tendonitis present with pain, tenderness, redness and pain on movement. Diagnosis is almost always clinical. Inflammatory indicators may be a bit elevated. Pain killers, anti-inflammatory drugs and steroids may be prescribed for tendinitis.
Tendonitis vs Bursitis
• Bursitis is isolated inflammation of a tendinous bursa located outside the joint between bones, muscles and tendons.
• Tendinitis is the isolated inflammation of the muscle tendon.