The dressings are then removed and the lesion is treated with light at a specified wavelength. Multiple treatment regimens using different photosensitizers, incubation times, light sources, and pretreatment regimens have been studied and suggest that longer incubation times lead to higher rates of lesion clearance. Photodynamic therapy is gaining in popularity. It has been found to have a 14% higher likelihood of achieving complete lesion clearance at 3 months compared to cryotherapy, and seems to result in superior cosmetic outcomes when compared to cryotherapy or 5-FU treatment. Photodynamic therapy can be particularly effective in treating areas with multiple AK lesions. Surgical techniques
Surgical excision: Excision should be reserved for cases when the AK is a thick, horny papule, or when deeper invasion is suspected and histopathologic diagnosis is necessary. It is a rarely utilized technique for AK treatment. Shave excision and curettage (sometimes followed by electrodesiccation when deemed appropriate by the physician): This technique is often used for treatment of AKs, and particularly for lesions appearing more similar to squamous cell carcinoma, or those that are unresponsive to other treatments. The surface of the lesion can be scraped away using a scalpel, or the base can be removed with a curette. Tissue can be evaluated histopathologically under the microscope, but specimens acquired using this technique are not often adequate to determine whether a lesion is invasive or intraepidermal. Dermabrasion: Dermabrasion is useful in the treatment of large areas with multiple AK lesions.
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