title: Lateral transpsoas interbody fusion (LTIF) with plate fixation and unilateral pedicle screws: a preliminary report.
abstract: METHODS
  Retrospective cohort study.
  
  
  OBJECTIVE
  We present the radiographic and clinical outcomes of 13 patients who underwent lateral transpsoas interbody fusion (LTIF) stabilized by unilateral pedicle screw instrumentation and anterior instrumentation.
  
  
  BACKGROUND
  LTIF is a surgical technique that permits anterior column lumbar interbody fusion via a direct lateral transpsoas approach. Because of the inherent stability of the implants used and the minimal disruption of stabilizing ligaments associated with LTIF, this technique may allow use of less invasive adjunctive fixation methods including unilateral pedicle screw fixation.
  
  
  METHODS
  Information from medical records included patient demographics, medical comorbidities, clinical assessment, surgical time, blood loss, implant information, and complications. Oswestry Disability Index, Short Form-12, and visual analog pain scale scores were obtained. Postoperative imaging allowed assessment of fusion, subsidence, and alignment.
  
  
  RESULTS
  Estimated blood loss averaged 225 mL and operative time averaged 261 minutes. No patients received a transfusion. Average length of hospital stay was 4.6 days. Oswestry Disability Index, Short Form-12, and visual analog pain scores demonstrated significant improvement. All patients with available 1 year postoperative imaging demonstrated solid fusion with average cranial and caudal subsidence of 1.8 and 0.8 mm, respectively. Two patients developed postoperative nondisplaced vertebral fractures through the anterior fixation screw tracts. Three patients developed transient postoperative hip flexion weakness and one also developed transient hypoesthesia in the anterior thigh, likely approach related.
  
  
  CONCLUSIONS
  We report a series of patients treated with unilateral pedicle screw fixation with LTIF. Although the patient cohort is small, validated outcomes instruments were used and fusion was assessed by computed tomography scan in most cases. The data suggest that unilateral pedicle screw fixation may be adequate to achieve high fusion rates after LTIF surgery using anterior instrumentation. Applying this technique in patients with osteoporosis may lead to a significant risk of postoperative vertebral body fracture.
authors.affiliation: Spine and Scoliosis Service, Department of Orthopaedic Surgery, Hospital for Special Surgery, 535 East 70th Street, New York, NY, USA. chris.kepler@gmail.com
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Kepler
authors.forename: Amit K
authors.initials: AK
authors.lastname: Sharma
authors.forename: Russel C
authors.initials: RC
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016268:Internal Fixators; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome