A synovial bursa (plural bursae or bursas) is a small fluid-filled sac lined by synovial membrane with an inner capillary layer of viscous synovial fluid (similar in consistency to that of a raw egg white). It provides a cushion between bones and tendons and/or muscles around a joint. This helps to reduce friction between the bones and allows free movement. Bursae are found around most major joints of the body. Structure
There are four types of bursa: adventitious, subcutaneous, synovial, and sub-muscular. Among these, only adventitious is non-native. When any surface of the body is subjected to repeated stress, an adventitious bursa develops under it. Examples are Students elbow and bunion. Clinical significance
Infection or irritation of a bursa leads to bursitis (inflammation of a bursa). The general term for disease of bursae is "bursopathy." History
Etymology
Bursa is Medieval Latin for "purse", so named for the resemblance of an anatomical bursa to a purse. Bursae or bursas is its plural form. See also
Bursa of Fabricius (a lymphatic organ in birds)
Bursectomy
Knee bursae
Shoulder joint#Bursae

External links

Hirji, Zameer; Hunjun, Jaspal S; Choudur, Hema N (2 May 2011). "Imaging of the Bursae". Journal of Clinical Imaging Science. 1: 22. doi:10.4103/2156-7514.80374. PMC 3177464. PMID 21966619. Bursa
Diagram of elbow with olecranon bursa
Higher frequency use of topical steroids provides benefit in difficult to treat cases.Diabetic macular edema may be treated with laser photocoagulation, reducing the chance of vision loss.In 2010, the US FDA approved the use of Lucentis intravitreal injections for macular edema.Iluvien, a sustained release intravitreal implant developed by Alimera Sciences, has been approved in Austria, Portugal and the U.K. for the treatment of vision impairment associated with chronic diabetic macular edema (DME) considered insufficiently responsive to available therapies. Additional EU country approvals are anticipated.In 2013 Lucentis by intravitreal injection was approved by the National Institute for Health and Care Excellence in the UK for the treatment of macular edema caused by diabetes and/or retinal vein occlusion.On July 29, 2014, Eylea (aflibercept), an intravitreal injection produced by Regeneron Pharmaceuticals Inc., was approved to treat DME in the United States. Research
In 2005, steroids were investigated for the treatment of macular edema due to retinal blood vessel blockage such as CRVO and BRVO.A 2014 Cochrane Systematic Review studied the effectiveness of two anti-VEGF treatments, ranibizumab and pegaptanib, on patients with macular edema caused by CRVO. Participants on both treatment groups showed a reduction in macular edema symptoms over six months.Another Cochrane Review examined the effectiveness and safety of two intravitreal steroid treatments, triamcinolone acetonide and dexamethasone, for patients with from CRVO-ME.