From Hospital to Ambulatory Surgery Center: Midline Cortical Pedicle Screws Vs. Traditional Pedicle Screws
Kingsley R. Chin, MD1, 2
Fabio J.R. Pencle, MB BS1
André V. Coombs, MB BS3
Mohamed Elsharkawy, MD3
Corrine F. Packer, MB BS3
Elijah A. Hothem, MD3
Jason A. Seale, MB BS1
- Less Exposure Surgery Specialists Institute (LESS Institute).
- Florida Atlantic University (FAU) & Florida International University (FIU)
- Less Exposure Surgery (LES) Society.
Conflicts of interest and sources of funding: We did not seek or receive any funding from the National Institutes of Health (NIH), Wellcome Trust, Howard Hughes Medical Institute (HHMI), or others for this work. KRC is a shareholder in and receives other benefits from SpineFrontier Inc., none of the other authors (FJRP, AVC, ME, CFP, EAH or JAS) have any potential conflicts of interest to declare for this work.
Modern advances in spine surgery including less invasive procedures have propelled the design of instruments and implants to achieve greater posterior spinal fixation, with decreased tissue destruction and higher safety margins. Static and dynamic biomechanical studies have validated the superior pullout strength of cortical screws versus the traditional pedicle screws and might represent an opportunity to perform safe lumbar fusions in ambulatory surgery centers (ASC). The authors aim to compare the outcomes of midline cortical pedicle screw surgical technique for posterior lumbar fixation in the ASC compared to traditional pedicle screws in a hospital.
The medical records of 60 patients with prospectively collected data were reviewed. Two matched cohort groups consisting of 30 patients each, midline cortical pedicle screws performed in ASC patients (Group 1) was compared to traditional pedicle screws performed in Hospital patients (Group 2). Outcomes were measured using Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI) scores, estimated blood loss (EBL) and Radiologic fusion rate.
33 males and 27 females, age range (28-75), average 58±3 years. Average BMI was 29±1.15 kg/m2. Significant improvement noted in VAS back pain scores in Group 1 from 7.8±0.5 to 2.5±0.7, p=0.001. Comparing VAS back pain scores and ODI scores, significant improvement demonstrated between group 1 and 2, p=0.004 and p=0.027 respectively. Mean EBL in group 1 was significantly less, p=0.025 than group 2. Intergroup fusion rate at two year was similar, p=0.855.
We successfully transitioned our lumbar fusions from hospitals to ambulatory surgery centers using a midline cortical pedicle screw technique. Although traditional pedicle screw placement was effective and may be viable in an ambulatory surgery center we see more advantages to use midline cortical screws over traditional pedicle screws.