S21.409 - Unspecified open wound of unspecified back wall of thorax with penetration into thoracic cavity S21.4 - Open wound of back wall of thorax with penetration into thoracic cavity S21.40 - Unspecified open wound of back wall of thorax with penetration into thoracic cavity S21.409 - Unspecified open wound of unspecified back wall of thorax with penetration into thoracic cavity