Synovial cyst of the fifth digit in a cat

Abstract

A synovial cyst of the fifth digit of the left forelimb in a 15-year-old cat was diagnosed. Radiographs showed severe osteoarthritis of the interphalangeal and metacarpophalangeal joints with soft tissue swelling. An ultrasound examination of the digit revealed a cystic structure. Following amputation of the digit, the cyst recurred 3 months later palmar to the carpus and metacarpus. The aetiology of synovial cysts is discussed.

Equine Articular Synovial Cysts: 16 Cases

“…A similar association between articular synovial cysts and underlying joint pathology has also been reported in dogs and cats . It is speculated that increased intraarticular pressure, secondary to joint inflammation, facilitates dissection of the synovial fluid and synoviocytes into the periarticular space where they gradually form a cystic structure.…”

“…He hypothesized that the synovial fluid exuded from the joint in the direction of least resistance through either weak regions in the fibrous capsule such as openings for blood vessels, or by first forming a hernia of the synovial membrane. Articular synovial cysts have also occasionally been described in cats (elbow and digit) and dogs (carpus and spine) and also associated with joint problems including osteoarthritis and carpal luxation…”

“…The terminology used to describe outpouchings or fluid filled, cyst‐like swellings located in proximity to synovial cavities is somewhat confusing because a variety of different descriptors have been used interchangeably. Terms used in the veterinary literature include synovial hernia or cyst, ganglia and ruptured capsule . Similarly, in human medical literature, comparable lesions are variably referred to as synovial cysts or hernias, ganglia, ganglia cysts, ganglia‐like pseudocysts, mucoid cysts and myxoid cysts …”

Medial humeral epicondylitis in clinically affected cats

“…In a second cat, only mild (grade 1) lameness was present postoperative. This cat also had a synovial cyst and any association with MHE is unclear although the formation of bone spurs may have contributed to weakening or perforation of the joint capsule . In contrast, only 1 cat treated conservatively had resolution of lameness by the end of the study.…”

“…This cat also had a synovial cyst and any association with MHE is unclear although the formation of bone spurs may have contributed to weakening or perforation of the joint capsule. [24][25][26][27] In contrast, only 1 cat treated conservatively had resolution of lameness by the end of the study. Conservative treatment consisted of both a nonsteroidal anti-inflammatory drug and glucosamine/chondroitin sulfate.…”