Bursitis

Introduction

Bursitis is defined as an inflammatory reaction within a bursa. This can range from mild inflammation to septic bursitis.

It is most common and important in the horse.

A bursa is present on a limb or at specific areas of the body that generally have limited movement but with pressure against a portion of bone, tendon or ligament. A bursa can also be found in areas to facilitate the gliding action of a tendon.

True or natural bursae are located in a predictable position and examples include: navicular bursa, prepatellar bursa, cunean bursa, bicipital bursa, trochanteric bursa and the subtendinous bursa of the common calcaneal tendon.

Acquired bursa develop subcutaneously in response to pressure and friction. Tearing of the subcutaneous tissue allows fluid to accumulate and become encapsulated by fibrous tissue. These include: olecranon bursa (capped elbow), subcutaneous calcaneal bursa (capped hock) and carpal hygroma.

Bursa may communicate with a joint or tendon sheath and may become clinically apparent because effusion from the joint or sheath cases filling of the bursa.

True bursitis involves a natural bursa and is caused by direct trauma or associated with the stress of racing or performance. This form of bursitis is called traumatic bursitis.

Acquired bursitis is either the development of a subcutaneous bursa or inflammation of that bursa.

If a bursa becomes infected, septic bursitis occurs and this is commonly following a puncture wound.

Clinical Signs

Bicipital, trochanteric and cunean bursitis are characterised by lameness. Pain can be elicited through palpation in bicipital and trochanteric bursitis, but cunean bursitis needs local blocking to define.

Acquired bursae do not usually lead to lameness and are characterised by a local, fluctuant swelling in the region. With chronicity they become firm and can cause mechanical limitation to flexion of the corresponding joint.

Septic bursitis, such as septic navicular bursitis is characterised by severe lameness and the recognition of foreign body penetration.

Diagnosis

Radiography to confirm a swelling of fluid/soft tissue opacity.

Ultrasonography to confirm a fluid-filled structure.

Sampling to investigate the nature of the fluid. In cases of septic bursitis, intracellular bacteria and degenerate neutrophils will be observed.

Treatment

The treatment methods vary considerably depending on the bursa.

Rest is the method of choice for bicipital bursitis. Cold applications can be used in all cases in the early acute stages.

For cunean tendon bursitis, options include cunean tenectomy, rest, local anti-inflammatory injections or phenylbutazone.

Acquired bursae of the elbow, hock or carpus should firstly be treated by preventing further trauma to the region. Local corticosteroid injections and pressure bandaging have been used in the past.

The contents of the bursa can be aspirated, or drains implanted.

For more chronic cases, surgical removal and primary closure is the treatment of choice. If immobilisation of the region can be performed, results can be good.

In septic bursitis, treatment requires systemic antibiotics as well as local drainage. The prognosis for complete recovery is guarded.

References

Kahn, C. (2005) Merck Veterinary Manual Merck and Co

Stashak, T. (1996) Practical guide to lameness in horses Wiley-Blackwell

McKinnon, A. (1998) Equine diagnostic ultrasonography Wiley-Blackwell