S66.012 - Strain of long flexor muscle, fascia and tendon of left thumb at wrist and hand level S66.0 - Injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level S66.01 - Strain of long flexor muscle, fascia and tendon of thumb at wrist and hand level S66.012 - Strain of long flexor muscle, fascia and tendon of left thumb at wrist and hand level