Fourth and fifth carpometacarpal fracture and dislocation of the hand: new classification and treatment

• Published in: European journal of orthopaedic surgery & traumatology Vol. 22; no. 7; pp. 571 - 578
• Main Authors: Lee, Sang-Uk, Park, Il-Jung, Kim, Hyoung-Min, Jeong, Changhoon, Oh, Jin-Rok
• Format: Journal Article
• Language: English
• Published: Paris Springer-Verlag 01-10-2012; Springer Nature B.V
• Subjects: Classification; Medicine; Medicine & Public Health; Original Article; Surgical Orthopedics; Traumatic Surgery; Fracture and dislocation; Operative treatment; Fourth and fifth carpometacarpal joint; Classification
• ISSN: 1633-8065; 1432-1068
• DOI: 10.1007/s00590-011-0887-6

Cain’s classification of fourth and fifth carpometacarpal (CMC) fracture and dislocation does not include the intraarticular metacarpal (MC) base fracture that may influence the treatment outcome. We reviewed 37 cases of fourth and fifth CMC fracture and dislocation treated with operative method, and we have devised a new classification based on the articular surface of the hamate and the involvement of the MC base. These injuries were divided into three types (type I, involved less than one-third of hamate articular surface; type II, involved more than one-third; and type III, coronal splitting of hamate). Each type was divided into four subtypes (a, absence of intraarticular MC base fracture; b, fourth MC base fracture; c, fifth MC base fracture; d, both fourth and fifth MC base fractures). Twenty cases were classified as type I, 16 as type II and 1 as type III. Stable hamate fracture (type I) was treated with closed reduction and percutaneous fixation, whereas unstable fracture (II and III) was treated with open reduction. Thirty-five of 37 patients showed excellent or good outcomes according to the Kumar’s criteria at 1 year postoperatively. The new classification classifies the fourth and fifth CMC fracture and dislocation in detail and appears to be more useful clinically.