Boutonniere deformity
Encyclopedia
Boutonniere deformity is a deformed position of the fingers or toes, in which the joint nearest the knuckle (PIP) is permanently bent toward the palm while the furthest joint (DIP) is bent back away (PIP flexion
with DIP
hyperextension). It is commonly caused by injury or by an inflammatory condition like rheumatoid arthritis
.
Higher numbers indicate a more severe problem and greater likelihood of a poor final outcome.
boutonnière "button hole"). The distal joint is subsequently drawn into hyperextension because the two peripheral slips of the extensor tendon are stretched by the head of the proximal phalanx(note that the two peripheral slips are inserted into the distal phalanx, while the proximal slip is inserted into the middle phalanx). This deformity makes it difficult or impossible to extend the proximal interphalangeal joint.
Flexion
In anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
with DIP
Distal interphalangeal joint
Distal interphalangeal joint can refer to:* Interphalangeal articulations of hand* Interphalangeal articulations of foot...
hyperextension). It is commonly caused by injury or by an inflammatory condition like rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
.
Stages
- Mild extension lag, passively correctable
- Moderate extension lag, passively correctable
- Mild flexion contracture
- Advanced flexion contracture
Higher numbers indicate a more severe problem and greater likelihood of a poor final outcome.
Pathophysiology
This flexion deformity of the proximal interphalangeal joint is due to interruption of the central slip of the extensor tendon such that the lateral slips separate and the head of the proximal phalanx pops through the gap like a finger through a button hole (thus the name, from FrenchFrench language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
boutonnière "button hole"). The distal joint is subsequently drawn into hyperextension because the two peripheral slips of the extensor tendon are stretched by the head of the proximal phalanx(note that the two peripheral slips are inserted into the distal phalanx, while the proximal slip is inserted into the middle phalanx). This deformity makes it difficult or impossible to extend the proximal interphalangeal joint.
External links
- http://medicine.ucsd.edu/clinicalimg/upper-hand-boutonniere.html
- http://www.merck.com/mmpe/sf/multimedia/Photo2sec04ch34/t/sec04-ch034-ch034b.html
- MRI sequence of disruption of the extensor tendon slip