Rj. Cole et Pr. Manske, CLASSIFICATION OF ULNAR DEFICIENCY ACCORDING TO THE THUMB AND FIRST WEB, The Journal of hand surgery, 22A(3), 1997, pp. 479-488
Fifty-five ulnar-deficient upper extremities in 45 patients treated al
the St. Louis Shriner's Hospital were reviewed in order to evaluate t
he hand abnormalities. Thumb and first-web abnormalities were noted in
73% of hands. The majority of operations (28 of 53) were recommended
to improve functional deficits associated with abnormalities of the th
umb and first web. A classification of the ulnar-deficient hand based
upon the characteristics of the thumb and first web is presented. When
used in combination with any of the six current forearm/elbow classif
ication schemes, this classification more completely describes ulnar d
eficiency of the upper extremity. Four classification types are propos
ed based upon progressive involvement of the thumb and first web. In t
ype A, the thumb and first web are normal; in type B, the first web sp
ace has mild deficiency and the thumb has mild involvement. Extrinsic
tendon function is intact and opposition function is present. In type
C, the thumb has varying degrees of involvement. The first web has mod
erate to severe deficiency, including thumb-index syndactyly, and is o
ften associated with malrotation of the thumb into the plane of the ot
her digits, loss of opposition, and dysfunction of the extrinsic tendo
ns. In type D, the thumb is absent. Previous classifications of ulnar
deficiency neglect the radial hand anomalies that have been noted by s
everal authors in a high percentage of affected extremities. Our premi
se for this classification is that the thumb and first-web abnormaliti
es are related to the complexity of the hand problem and that the freq
uently noted radial hand abnormalities require the majority of surgica
l procedures. Such a classification based on the thumb and first-web d
eformities will focus the surgeon's attention On those deficiencies th
at are most important for the restoration of function. It is proposed
that ulnar deficiency be classified by one of the classification schem
es that describes the anatomy of the forearm and/or elbow supplemented
by the hand classification type.