S31.00 - Unspecified open wound of lower back and pelvis S31.0 - Open wound of lower back and pelvis S31.00 - Unspecified open wound of lower back and pelvis S31.000 - Unspecified open wound of lower back and pelvis without penetration into retroperitoneum S31.001 - Unspecified open wound of lower back and pelvis with penetration into retroperitoneum