Boutonniere deformity explained

Boutonniere deformity is a deformed position of the fingers or toes, in which the joint nearest the knuckle (the proximal interphalangeal joint, or PIP) is permanently bent toward the palm while the farthest joint (the distal interphalangeal joint, or DIP) is bent back away (PIP flexion with DIP hyperextension). Causes include injury,^[1] inflammatory conditions like rheumatoid arthritis, and genetic conditions like Ehlers-Danlos syndrome.^[2]

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 French 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.

Diagnosis

Stages

1. Mild extension lag, passively correctable
2. Moderate extension lag, passively correctable
3. Mild flexion contracture
4. Advanced flexion contracture

Higher numbers indicate a more severe problem and greater likelihood of a poor outcome.

Treatment

Usually treated with a splint placing the proximal interphalangeal joint in extension for 4–6 weeks. Occasionally surgery is needed when splinting is unsuccessful.

See also

• Swan neck deformity
• Z-deformity

Further reading

• Coons . Matthew S. . Green . Steven M. . Boutonniere deformity . Hand Clinics . August 1995 . 11 . 3 . 387–402 . 10.1016/S0749-0712(21)00060-3 . 7559817 .
• Souter . William A. . The Problem of Boutonniere Deformity . Clinical Orthopaedics and Related Research . October 1974 . 104 . 104 . 116–133 . 10.1097/00003086-197410000-00012 . 4607222 .
• Nalebuff . Edward A. . Millender . Lewis H. . Surgical Treatment of the Boutonniere Deformity in Rheumatoid Arthritis . Orthopedic Clinics of North America . July 1975 . 6 . 3 . 753–763 . 10.1016/S0030-5898(20)30987-1 . 1099508 .
• Littler . J. William . Eaton . Richard G. . Redistribution of Forces in the Correction of the Boutonnière Deformity . JBJS . October 1967 . 49 . 7 . 1267–1274 . 10.2106/00004623-196749070-00002 . 5622971 .
• To . Philip . Watson . Jeffry T. . Boutonniere Deformity . The Journal of Hand Surgery . January 2011 . 36 . 1 . 139–142 . 10.1016/j.jhsa.2010.10.032 . 21193133 .
• Massengill . James B. . The boutonniere deformity . Hand Clinics . November 1992 . 8 . 4 . 787–801 . 10.1016/S0749-0712(21)00744-7 . 1460075 .
• Aiache . Adrien . Barsky . Arthur J. . Weiner . Daniel L. . Prevention of the boutonniere deformity . Plastic and Reconstructive Surgery . August 1970 . 46 . 2 . 164–167 . 10.1097/00006534-197008000-00010 . 5423482 . 39268503 .
• Curtis . Raymond M. . Reid . Robert L. . Provost . John M. . A staged technique for the repair of the traumatic boutonniere deformity . The Journal of Hand Surgery . March 1983 . 8 . 2 . 167–171 . 10.1016/s0363-5023(83)80009-4 . 6833725 .
• Urbaniak . James R. . Hayes . Michael G. . Chronic boutonniere deformity—An anatomic reconstruction . The Journal of Hand Surgery . July 1981 . 6 . 4 . 379–383 . 10.1016/s0363-5023(81)80048-2 . 7252114 .
• Dolphin . James A. . Extensor Tenotomy for Chronic Boutonnière Deformity of the Finger: REPORT OF TWO CASES . JBJS . January 1965 . 47 . 1 . 161–164 . 10.2106/00004623-196547010-00011 . 14256963 .

Notes and References

1. Web site: Boutonniére Deformity . Your Orthopaedic Connection . American Academy of Orthopaedic Surgeons . 15 April 2018.
2. Web site: Boutonniere Deformity.