A classification system for ulnar polydactyly and clinical series

Area of Science:

• Orthopedic surgery
• Congenital hand anomalies
• Pediatric orthopedics

Background:

• Ulnar polydactyly is a common congenital hand anomaly.
• Existing classification systems do not adequately address complicated ulnar polydactyly or ulnar polydactyly with bifid proximal phalanx.
• Accurate classification is crucial for effective surgical management.

Purpose of the Study:

• To introduce a modified classification system for ulnar polydactyly.
• This system integrates both complicated ulnar polydactyly and ulnar polydactyly with bifid or duplicated proximal phalanx.
• To apply this novel classification to a clinical series of patients.

Main Methods:

• Retrospective analysis of clinical and radiological data from 42 patients with ulnar polydactyly.
• Patients were seen between January 2004 and January 2014.
• Data were organized into 5 distinct subgroups based on morphology and duplication characteristics.

Main Results:

• The study included 42 patients (20 bilateral, 22 unilateral).
• Supernumerary digits were classified into types I-V.
• Nine patients presented with bifid or duplicated proximal phalanges (types IIIA and IIIB), and 2 with complicated ulnar polydactyly (type V).

Conclusions:

• Complicated ulnar polydactyly and ulnar polydactyly with bifid proximal phalanx are distinct entities with significant surgical implications.
• Current classification systems (Pritsch, Rayan, Al-Qattan) do not encompass both types simultaneously.
• The proposed modified classification aims to enhance diagnostic accuracy and guide treatment strategies for these specific ulnar polydactyly variations.