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.
