Inﬂammatory type causes include:
Rheumatoid arthritis (proliferative) - this produces relatively painless and bulky swellings
Deposition pathologies - conditions where normal excreted protein products are well excreted or poorly broken down so that they accumulate and get deposited in the tissues including tendons /other soft tissues, joints and bones. This includes amyloidosis and ochronosis.
Amyloidosis is due to the deposition of a low molecuar weight serum protein (beta microglobulin) in patients undergoing renal dialysis as the protein is not ﬁltered by normal dialysis membranes or rarely because of an enzymatic defect. Ochronosis is deposition of homogentisic acid in the tissues and as well as excreted in the urine. in this autosomal recessive condition, there is an enzyme deﬁciency in tryptophan metabolism. (homogentisic acid oxidase)
Crystalline tendinopathy - gout (urate crystals), calciﬁc tenosynovitis, pseudogout (calcium
Infective - this can be acute or chronic (fungal, atypical mycoacteria, gonococcal).
Sarcoidosis - It is an immune mediated granulomatous disease but the cause is unknown.
Reactive causes are more common. This is also referred to as stenosing tendovaginitis and is associated with thickening of the tendon or the retinacular sheath. Examples of the condition is trigger ﬁnger and De Quervain's disease.
The tendons pass through ﬁbro-osseous canals on the back of the wrist (dorsum) or the palmar side of the tendons. They provide fulcrums for the acute angulation of these tendons. These canals are narrow and during this constant motion, there can be swelling and bunching of the tendon ﬁbres which can lead to a restriction of gliding and ﬁnallycatching or locking of the tendon. This process leads to an acute inﬂammatory response with resultant edema and thickeneing of the retinacular sheath.
Symptoms include local pain and tenderness, swelling, redness and crepitus. Triggering of the digits and weakening of the grip strength depending on the site of the tenosynovitis may follow. Carpal tunnel syndrome can occur