Thumb-in-palm deformity in arthrogryposis multiplex congenita: A severity-based classification and structured surgical approach.

Thumb-in-palm deformity significantly limits hand function in arthrogryposis multiplex congenita (AMC), resulting from intricate interactions between contracted thumb-index web skin, restrictive intrinsic musculature, joint instability, and compromised extrinsic tendons, collectively causing thumb adduction, flexion, and poor opposition. Due to the complexity of this deformity, surgical outcomes have historically varied. We introduced a severity-based classification system-mild, moderate, or severe-to guide treatment decisions. Mild cases were addressed conservatively, moderate cases underwent single-stage reconstructive surgery, and severe deformities required two-stage procedures, sometimes addressing concurrent finger contractures. A preliminary clinical series involving 16 thumbs demonstrated promising results, with the majority achieving excellent functional outcomes as assessed by a modified Gilbert grading system. Minimal complications were noted. Our structured surgical strategy based on deformity severity enhances functional recovery, allowing tailored management and improved consistency of outcomes.