title: Systematic Review of Thigh Symptoms after Lateral Transpsoas Interbody Fusion for Adult Patients with Degenerative Lumbar Spine Disease.
abstract: BACKGROUND
  Lateral transpsoas interbody fusion (LTIF) is a minimally invasive technique for achieving lumbar spinal fusion. While it has many advantages over open techniques it carries with it a distinct set of risks, most commonly post-operative ipsilateral thigh pain, weakness and sensory disturbances. It is vital for both the surgeon and patient to understand the risks for and outcomes of injury associated with this procedure. We conducted a systematic review of the literature to evaluate the incidence, risks, and long-term clinical outcomes of post-operative thigh symptoms in patients treated with LTIF.
  
  
  METHODS
  We conducted a search of MEDLINE, EMBASE, CINAHL, Scopus, Web of Science and the Cochrane Collaboration Library, using keywords and MeSH terms, for English-language literature published through September 2014, as well as reference lists from key articles. Studies were then manually filtered to retrieve articles that met inclusion criteria. We were interested in studies that reported postoperative lower extremity symptoms after LTIF, such as pain, weakness and changes in sensation. The strength of evidence was determined based on precepts outlined by the Grades of Recommendation Assessment, Development and Evaluation Working Group (GRADE).
  
  
  RESULTS
  A total of 392 articles were initially retrieved, with 24 ultimately meeting criteria for inclusion. The incidence of any post-operative thigh symptom varied, ranging as high as 60.7%, with 9.3% of patients experiencing a motor deficit related to direct nerve injury. Several studies reported cases of persistent symptoms at 6 months follow up. Additionally, inclusion of the L4-5 disc space and a longer duration of surgery were both identified as risks for developing postoperative thigh symptoms.
  
  
  CONCLUSIONS
  The risk of postoperative thigh symptoms after LTIF is high. Thigh pain, paresthesias and weakness were the most commonly reported symptoms. While most patients' symptoms resolved by 6 months follow up, several studies reported patients with symptoms persistent as far as 12 months removed from surgery. Surgery at the L4-5 disc space and longer surgical duration place the patient at greater risk for developing postoperative and long-term thigh symptoms.
authors.affiliation: Division of Spine Surgery, Hospital for Joint Diseases, NYU Langone Medical Center, New York, NY.
authors.forename: Isaac D
authors.initials: ID
authors.lastname: Gammal
authors.affiliation: Division of Spine Surgery, Hospital for Joint Diseases, NYU Langone Medical Center, New York, NY.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Spivak
authors.affiliation: Division of Spine Surgery, Hospital for Joint Diseases, NYU Langone Medical Center, New York, NY.
authors.forename: John A
authors.initials: JA
authors.lastname: Bendo
keywords: lateral lumbar interbody fusion; minimally invasive spine surgery; transpsoas interbody fusion