Becker's Spine Review

33 Executive Briefing Sponsored by: T he lateral interbody fusion (LIF) spine procedure was developed two decades ago and offers not only many MIS benefits, but also superior biomechanical stability and high fusion rates. Even with the well-documented benefits of LIF, many surgeons have not adopted this now traditional technique, and a majority of surgeons have found that there are some inherent challenges when the patient is in the lateral decubitus position. Not only can the position be unfamiliar to the surgeon and staff which leads to inefficiencies in preoperative setup and repositioning for posterior procedures, but literature demonstrates that the lateral decubitus position may not be ideal for achieving sagittal alignment - the greatest correlative to a long-term positive outcome. What if there were a lateral approach that appealed to more surgeons, provided a greater ability to achieve alignment goals, and resulted in excellent patient outcomes? Luiz Pimenta, MD, PhD, Medical Director at Instituto de Patalogia da Coluna, and William Taylor, MD, Clinical Professor of Surgery in the Division of Neurosurgery at University of California San Diego, partnered with Alphatec Spine to develop a more streamlined intuitive lateral approach, Prone Transpsoas or "PTP". As its name suggests, PTP is a spinal fusion procedure in which the patient is positioned prone and the disc space is accessed laterally through the psoas muscle. "Despite the advantages of lateral spinal fusion, including good corrections, low infection risk, and lower complication risk than alternative procedures, there was still reluctance by surgeons to adopt," said Dr. Taylor. "Overcoming that reluctance became our goal and when we were looking at the lateral approach. We had to rethink and redo the entire lateral approach to make it more palatable for surgeons to adopt." "This is not just another lateral spine procedure," said Dr. Pimenta. "PTP allows us to achieve better coronal and sagittal alignment by keeping the patient in a maximally efficient prone position throughout both the anterior and posterior aspects of the case." In this article, you will find a discussion of how the PTP procedure could spark more widespread use of the lateral approach for spinal fusion surgery. Question: What are the benefits of PTP? Dr. William Taylor: PTP has many benefits that range from superior surgical efficiency to powerful correction abilities in both the sagittal and coronal planes. From an efficiency standpoint, it reduces preoperative positioning time and eliminates the need for taping that is required in traditional LIF procedures. You also have the ability to perform posterior surgery simultaneously. PTP allows me to perform a LIF at L4/5 with a direct decompression while simultaneously completing a TLIF at L5/S1. PTP also simplifies decision-making. With patients in the lateral position you have to ask yourself: Do I put in pedicle screws? Do I flip them over to do a decompression? How can I achieve better sagittal correction? Now, all the decision- making is simplified. I can do a direct decompression without having to reposition the patient, which saves time and eliminates my reliance on indirect decompression. Dr. Luiz Pimenta: There have been some questions about how much sagittal alignment we can restore with the traditional lateral procedure and the reality is that with PTP we have a greater ability to restore alignment and perform surgery in a more efficient fashion. WT: When surgeons observe us performing PTP, they see the benefits right away because there is less time spent po- sitioning and/or repositioning the patient, easier access to the retroperitoneal space, less concern about neural inju- ry, greater sagittal correction, and simultaneous anterior/ posterior column access to achieve your overall alignment goals. The decision-making tree has been simplified. Q: How has the procedure evolved? WT: We have collectively done more than 1,000 PTP cases and learned quickly that the requirements around PTP differ greatly when compared to traditional lateral surgery. We developed each component of the procedure based on the clinical requirements for the patient in the prone position. First, the carbon-fiber patient positioning system allows for reproducible access to patients with high iliac crests, and provides patient stability throughout the procedure. Next, we focused on developing a solid low- profile two-bladed retractor that attaches directly to the patient positioner and can independently open posteriorly and anteriorly. The retractor allows the surgeon to expose 'This is not Prone Lateral, this is PTP': Key advantages of the Prone Transpsoas (PTP) technique

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