%0 Journal Article %A Khalid AlSaleh %A Abdulrahman Aldowesh %A Muteb Alqhtani %A Musab Alageel %A Abdulmajeed AlZakri %A Osama Alrehaili %A Waleed Awwad %T Subcutaneous Fat Thickness on Erect Radiographs Is a Predictor of Infection Following Elective Posterior Lumbar Fusion %D 2022 %R 10.14444/8295 %J International Journal of Spine Surgery %P 660-665 %V 16 %N 4 %X Background Posterior lumbar fusions are a common and successful procedure, yet surgical site infection (SSI) is still prevalent and causes significant morbidity. Obesity is a well-established risk factor for SSI. Still, the accuracy of the body mass index (BMI) caused some to suggest other metrics that are more representative of the thickness of the soft-tissue envelope in the surgical site.Methods A retrospective review of all cases that developed SSI following posterior lumbar fusion over the past 5 years was done. An age and gender-matched control group was formed from the lumbar fusion cases that did not develop SSI. Demographic and clinical data were collected, and morphometric measurements of the soft-tissue envelope were performed at the level of L4 for all cases on standing x-ray imaging and magnetic resonance imaging (MRI).Results A total of 366 patients underwent posterior lumbar fusion, 26 of whom developed SSI. BMI and skin to spinous process measurements on x-ray imaging—not MRI—were found to be significantly associated with SSI. Regression analysis further confirmed the strength of the association.Conclusion While BMI and MRI measurements are useful, wound depth measurements on x-ray imaging can be predictive of SSI in lumbar fusion cases.Clinical Relevace Wound depth measurements are predictive of lumbar wound infection. The information within this study can help surgeons better predict and manage infections of posterior lumbar wounds.Level of Evidence 3. %U http://www.ijssurgery.com/content/ijss/16/4/660.full.pdf