Thumb Size and Appearance Following Reconstruction of Radial Polydactyly

Purpose: To evaluate thumb size, shape, and appearance after surgical correction of radial polydactyly. Methods: Thirty-one reconstructed thumbs in 26 children with radial polydactyly were evaluated at an average of 45 months after surgery. The length, girth, nail width, and joint angulation were measured and compared with the contralateral side of patients with unilateral polydactyly and with standard thumb measurements for patients with bilateral involvement. A surgeon, therapist, and caregiver each subjectively assessed the aesthetic outcome, using a visual analog scale (VAS); raters also provided the principal reasons for their assessment of the altered appearance. Results: The average length of the reconstructed thumb relative to the index finger proximal phalanx was 81%; that of the unaffected, contralateral thumb was 80%. The girth of the reconstructed thumb relative to the index finger was 102%; that of the contralateral thumb was 103%. Thumbnail width in proportion to index fingernail width was significantly decreased in the reconstructed thumbs, at 111% (compared with the contralateral value of 136%). The VAS scores averaged 7.7; the most common reason cited for decreased VAS score was an angulated thumb. Lower VAS scores were associated with Wassel type VI and VII thumbs and with increased interphalangeal, but not metacarpophalangeal, joint angulation. Conclusions: Thumb polydactyly reconstruction typically provides a satisfactory thumb appearance. The primary issues affecting appearance after reconstruction are reduced nail width, interphalangeal joint angulation, and presence of type VI and VII radial polydactyly. Type of study/level of evidence: Therapeutic IV.