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Anatomic Classifications and Functional Outcomes in Preaxial Polydactyly of the Hand
Danilo González-Zapata1,2, Sergio Martínez-Álvarez1, María Galán-Olleros1
1Department of Orthopaedic Surgery and Traumatology, Hospital Infantil Universitario Niño Jesús.
Journal of Pediatric Orthopedics
|August 14, 2026
Summary
This study on preaxial polydactyly found that surgical reconstruction yields good outcomes. The JK classification offers more detailed anatomic information than the Wassel-Flatt system for surgical planning and outcome prediction.
Area of Science:
- Hand surgery
- Congenital anomalies
- Orthopedic surgery
Background:
- Preaxial polydactyly is a common congenital hand anomaly with significant variability.
- Existing classification systems do not fully correlate with postoperative outcomes.
- This study aims to clarify the relationship between classification and surgical results.
Purpose of the Study:
- Evaluate clinical and radiographic outcomes after surgical reconstruction of preaxial polydactyly.
- Compare the Wassel-Flatt (WF) and JK classification systems' association with outcomes.
- Assess the utility of the Japanese Society for Surgery of the Hand (JSSH) and Rotterdam scoring systems.
Main Methods:
- Retrospective review of 58 patients (59 thumbs) treated surgically (2012-2024).
- Thumbs classified using WF and JK systems.
- Outcomes assessed included range of motion, alignment, stability, JSSH/Rotterdam scores, and reoperation rates.
Main Results:
- Most thumbs (53/59) achieved good/excellent outcomes per JSSH criteria.
- The JK classification showed better association with postoperative alignment and JSSH scores.
- Temporary K-wire fixation was linked to reduced range of motion, though causation is unclear.
Conclusions:
- Surgical reconstruction of preaxial polydactyly generally leads to favorable outcomes.
- The JK classification provides enhanced anatomic detail, especially for subtypes within WF categories.
- Further validation of JK classification's prognostic value in larger studies is warranted.
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