Chapter Clinical Summary
Academic synthesis, diagnostic methodology, and surgical recommendationsSingle-Position Lateral Surgery (SPLS) represents an advanced evolutionary milestone in lateral lumbar interbody fusion (LLIF). Historically, lateral interbody fusion required performing the retroperitoneal anterior interbody procedure in lateral decubitus, followed by re-draping and flipping the patient into prone position for posterior pedicle screw fixation. SPLS eliminates this repositioning by performing both the lateral interbody fusion and the posterior percutaneous pedicle screw fixation in a single lateral decubitus position. This streamlining markedly reduces total operative time, decreases anesthesia exposure, eliminates the risks associated with intraoperative patient turning, and enhances operating room efficiency. Furthermore, bilateral or unilateral percutaneous pedicle screw placement in lateral decubitus has been validated by computer navigation and robotic assistance. Successful execution demands precise patient positioning, deep familiarity with retroperitoneal psoas anatomy, and mastery of fluoroscopic and navigated trajectory alignment in lateral decubitus.
Detail the clinical rationale, positioning protocols, surgical workflow, and technical execution of Single-Position Lateral Surgery (SPLS). The reader will master the step-by-step technique of lateral interbody fusion followed immediately by navigated or fluoroscopy-guided posterior percutaneous screw fixation in lateral decubitus, alongside complication management and lordosis restoration strategies.
Conventional LLIF workflows require two separate patient positionings: lateral decubitus for the interbody fusion, followed by flipping to prone for posterior fixation. SPLS performs both stages in lateral decubitus, eliminating 30 to 60 minutes of repositioning and re-draping time, reducing anesthesia time, and lowering hospital costs while maintaining identical fusion and alignment outcomes.
The patient is positioned in true 90° lateral decubitus on a radiolucent breakable table. Taping and rigid table bolsters ensure stability during posterior instrumentation. The table is flexed to open the corridor between the iliac crest and rib cage for interbody access, and then returned to neutral or lordotic posture before posterior pedicle screw placement.
Retroperitoneal transpsoas approach is performed with continuous neuromonitoring to identify the lumbar plexus. Complete discectomy, contralateral annulotomy, and comprehensive endplate preparation are performed. A wide, lordotic interbody cage spanning both dense lateral cortical ring apophyses is inserted, achieving immediate mechanical stability, disc height restoration, and indirect neural decompression.
Without moving the patient, posterior percutaneous pedicle screw instrumentation is performed. Fluoroscopy, navigation, or robotic systems are easily calibrated in lateral decubitus. Segmental compression across the pedicle screws locks the interbody cage in place and induces supplemental segmental lordosis.
SPLS yields clinical outcomes, fusion rates, and lordosis restoration comparable to dual-position surgery with significantly reduced operative time and blood loss. Complications include transient psoas weakness, thigh dysesthesia, cage subsidence, and pedicle screw malposition, which are minimized by careful neuromonitoring and navigation.
In clinical practice, SPLS is indicated for degenerative disc disease, degenerative spondylolisthesis, adult spinal deformity, and adjacent segment disease from L1 to L5. The surgeon must evaluate preoperative CT and MRI to confirm safe retroperitoneal corridor anatomy and rule out high iliac crest obstruction at L4-L5. Intraoperatively, the patient must be rigidly secured to prevent rotational pelvic drift between the anterior and posterior stages. During the interbody stage, neurophysiological monitoring guides safe psoas transit. Following cage insertion, the table break is leveled to restore natural lordosis prior to placing percutaneous pedicle screws. Computer-assisted navigation or robotics is especially valuable in lateral decubitus to ensure accurate pedicle screw trajectory in non-standard spatial orientation.