S66.212 - Strain of extensor muscle, fascia and tendon of left thumb at wrist and hand level S66.2 - Injury of extensor muscle, fascia and tendon of thumb at wrist and hand level S66.21 - Strain of extensor muscle, fascia and tendon of thumb at wrist and hand level S66.212 - Strain of extensor muscle, fascia and tendon of left thumb at wrist and hand level