Related Experiment Video
Updated: Mar 15, 2026
Author Spotlight: Ultrasound-Guided Needle Release Combined with Corticosteroid Injection for the Treatment of Supinator Syndrome
Published on: May 26, 2023
Oligodactyly with Thumb
11 Department of Orthopaedic Surgery, Seoul National University College of Medicine Seoul, Korea.
Background:
Oligodactyly of the hand is one of the rarest congenital anomalies of upper extremities and defined as the presence of fewer than five fingers on a hand. Although it usually occurs in association with hypoplasia or absence of ulna, it can occur without abnormality of the forearm bones. The purpose of this study is to present clinical features and radiographic characteristics of hand oligodactyly with thumb.
Methods:
Five patients of oligodactyly with thumb who showed normal forearm bones, were evaluated. Two patients had threefingered hand with thumb, and three had two-fingered hand with thumb. We analyzed associated abnormalities of carpal and metacarpal bones and measured the lengths of radius and ulna, and width of the wrist on the simple radiographs. We also devised new classification system of oligodactyly based on the thumb deformities and locations of missing digits.
Results:
Syndactyly among fingers was associated in four patients, clinodactyly caused by delta bone in one, hypoplasia of the thumb in one, camptodactylies in one, symphalangism in one, and radial head dislocation in one. Considering the abnormalities of the carpal bones, the missing digits were presumed to be ulnar-sided digits in two patients, central digits in one patient and both ulnar-sided and central digits in two patients. In patients with missing of central digits, an adjacent metacarpal was hypertrophied. Although the ulnar variances were within normal range, the average lengths of radius and ulna were 6% and 5% shorter than those of contralateral normal side. The average width of the wrist was 9% narrower than that of contralateral normal side.
Conclusions:
Syndactyly and hypertrophied metacarpal were most commonly observed findings in the oligodactyly with thumb. Although oligodactyly with thumb may be a type of ulnar longitudinal deficiency, however, it can also be a type of central deficiency or combined type of ulnar longitudinal deficiency with central deficiency or radial longitudinal deficiency. We suggest a classification system of oligodactyly with thumb based on locations of missing digits and associated thumb deformities.
Related Concept Videos
01:15Bones of the Upper Limb: Ulna
01:16Muscles of the Forearm that Move the Hand and Fingers
Anterior Compartment
The anterior compartment muscles originate from the humerus. They primarily function as flexors and are also known as flexor muscles. They typically insert on the carpals, metacarpals, and phalanges. The superficial layer includes the flexor carpi...
01:09Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
01:09Bones of the Upper Limb: Radius
The radius has a nail-shaped head, and a...
01:07Development of the Limb Synovial Joints
The mesenchymal stem cells differentiate into chondrocytes that form the hyaline cartilage, and later the cartilaginous model of the bone. This model further transforms into a bone. This process is known as endochondral ossification.
During development, the limbs...
01:19Bones of the Upper Limb: Humerus