title: Minimally invasive transmuscular pedicle screw fixation of the thoracic and lumbar spine.
abstract: OBJECTIVE
  This study assessed the feasibility and safety of percutaneous posterior pedicle screw fixation for instabilities of the thoracic and lumbar spine, using standard instruments designed for the open approach and fluoroscopy.
  
  
  METHODS
  All patients who underwent percutaneous posterior pedicle screw fixation of the thoracic and lumbar spine were studied retrospectively. Charts and operative notes were analyzed for epidemiological data, underlying spinal pathological features, and indications for stabilization, stabilized segments, number of implanted pedicle screws, surgical time, and complications. Postoperative computed tomographic scans were analyzed for screw position.
  
  
  RESULTS
  From May 2002 through May 2005, 115 internal fixators were implanted percutaneously in 104 patients. A total of 488 pedicle screws were implanted, stabilizing 1 to 5 spinal motion segments. Median surgical time was 93 minutes. On postoperative computed tomographic scans, 87% of screw positions were rated good, 10% were rated acceptable, and 3% were rated unacceptable. A total of 11 revisions were necessary, 9 for misplaced screws and 2 for loosening of anchor bolts. Only two of the patients experienced new clinical symptoms (i.e., radicular pain) because of screw misplacement. No patients experienced new neurological deficits or other surgery-related morbidity.
  
  
  CONCLUSIONS
  This study shows that percutaneous internal pedicle screw fixation using standard instruments is feasible and safe for posterior stabilization of the thoracic and lumbar spine. It is a straightforward alternative for open approaches or minimally invasive ones using navigation in conjunction with customized instruments. Accuracy of screw placement is similar to that reported for other techniques.
authors.affiliation: Department of Neurosurgery, University of Bonn, Bonn, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Ringel
authors.forename: Michael
authors.initials: M
authors.lastname: Stoffel
authors.forename: Carsten
authors.initials: C
authors.lastname: Stüer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Meyer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D002648:Child; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D016268:Internal Fixators; D007593:Joint Instability / Q000601:surgery*; D007796:Laminectomy / Q000009:adverse effects / Q000379:methods; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D018482:Muscle, Skeletal / Q000601:surgery; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation; D013904:Thoracic Vertebrae / Q000601:surgery*; D016896:Treatment Outcome