S83.9 Sprain of unspecified site of kneeNon-billable header with 3 child codes.
S83.90 Sprain of unspecified site of unspecified kneeS83.91 Sprain of unspecified site of right kneeS83.92 Sprain of unspecified site of left kneeM23 Internal derangement of knee ("current injury - see injury of knee and lower leg (S80-S89)")S86 Injury of muscle, fascia and tendon at lower leg level ("sprain of joints and ligaments of knee (S83.-)")S83.8X2S Sprain of other specified parts of left knee, sequelaS83.8X9 Sprain of other specified parts of unspecified kneeS83.8X9A Sprain of other specified parts of unspecified knee, initial encounterS83.8X9D Sprain of other specified parts of unspecified knee, subsequent encounterS83.8X9S Sprain of other specified parts of unspecified knee, sequelaS83.9 Sprain of unspecified site of knee (this code)S83.90 Sprain of unspecified site of unspecified kneeS83.90XA Sprain of unspecified site of unspecified knee, initial encounterS83.90XD Sprain of unspecified site of unspecified knee, subsequent encounterS83.90XS Sprain of unspecified site of unspecified knee, sequelaS83.91 Sprain of unspecified site of right knee