To identify the current mortality rate for initial Anterior Lumbar Interbody Fusion(ALIF)procedures. Establish/prove mortality rates for this operation have dropped in the past decade.

Establish the mortality rate for "re-do" ALIF procedures [i.e., is it different than that of initial ALIF procedures and - if so - postulate that there are interventions that can be done in the pre-operative period to ameliorate that risk. This study is not designed to "prove" the latter hypothesis.]

This is a single sample study where medical records will be searched by Current Procedural Terminology(CPT) codes for ALIF codes (e.g. 22558, 22585, 22845, etc.) by trained researcher(s) at participating Methodist facilities going back 5-10 years to see if 1500-3500 cases can be identified within that time period.

Inclusion Criteria:

• Patients > 17 years of age, patients having had ALIF procedures as defined by CPT codes at participating Methodist facilities during 2010-2020 targeted.

Exclusion Criteria:

• Pediatric patients (as defined by age <18 years old), pregnant women and incarcerated individuals. We do not anticipate any of these in an elective spine surgery group of patients. If they have emergency spine surgery it is normally not an ALIF.

Patients > 17 years of age, patients having had ALIF procedures as defined by CPT codes at participating Methodist facilities during 2010-2020 targeted.

Study data or any protected health information will not be shared with anyone that is not delegated to the study. The PI is committed to disseminate research results in a timely fashion. Sharing of results generated by the data analysis during the course of the project will be through presentation at national scientific meetings and/or publication in open access journals. All information obtained will be source de-identified and presented on a large scale and not traceable to any one particular individual.