title: Spinal fracture reduction with a minimal-invasive transpedicular Schanz Screw system: clinical and radiological one-year follow-up.
abstract: BACKGROUND
  Surgical management of thoracolumbar trauma involves correction of posttraumatic deformity and placement of transpedicular instrumentation. The aim of this prospective cohort study was to generate first results reflecting the clinical and radiological outcome of patients treated with percutaneous dorsal instrumentation for fractures of the thoracic and lumbar spine with the use of a transpedicular new Schanz Screw system (USS Fracture MIS, DePuy Synthes).
  
  
  METHODS
  A total of 26 patients with fractures of the thoracic and lumbar spine were operatively treated with bi-segmental dorsal instrumentation between January and December 2012. Radiological data acquisition was performed pre- and postoperatively, after six weeks, three, six, and twelve months. The radiological parameter of interest was the bi-segmental kyphotic end plate angle (Cobb angle). The Chronic Disability Index (CDI), the Oswestry Disability Index (ODI), and the Spine Tango Core Outcome Measurement Index (COMI) were applied to investigate the clinical outcome.
  
  
  RESULTS
  The clinical follow-up was completed by 22 patients (84.6%), and the radiological follow-up by 21 (80.8%) patients. Our patient population had a mean age of 47.4 ± 4.1 years. Twelve patients received dorsal instrumentation, and 14 patients were treated with an additional ventral reconstruction. Intraoperative reduction was 11.5 ± 1.5° among all patients (p < 0.01). A considerable amount of the operative correction was lost after six weeks with a loss of reduction of 4.6 ± 1.4° (p < 0.01). At one year follow-up, the measured loss of reduction was significant in comparison to the postoperative state, 6.9 ± 1.3° among all patients, 8.7 ± 2.1° after dorsal and 4.9 ± 1.1° after dorsoventral stabilisation (all p < 0.01). Moreover, all patients had minimal to moderate disability with a CDI of 1.8 ± 0.4 (0 - 7), and an ODI of 15.6 ± 3.6 (0 - 60).
  
  
  CONCLUSIONS
  The new transpedicular Schanz screw system can deliver a correction and stabilization of thoracic and lumbar spine fractures. Patients report minimal to moderate disability as a result of their severe injury one year after trauma. We advocate the use of the transpedicular Schanz screw system to correct posttraumatic kyphotic deformity, with secondary anterior fusion in our treatment strategy of thoracolumbar incomplete burst fractures in patients without a neurologic deficit.
authors.affiliation: Department of Trauma Surgery, Regensburg University Medical Center, Davos, Switzerland. Electronic address: markus.loibl@ukr.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Loibl
authors.affiliation: Department of Trauma Surgery, Regensburg University Medical Center, Davos, Switzerland.
authors.forename: Mariya
authors.initials: M
authors.lastname: Korsun
authors.affiliation: Department of Trauma Surgery, Regensburg University Medical Center, Davos, Switzerland.
authors.forename: Julian
authors.initials: J
authors.lastname: Reiss
authors.affiliation: AO Research Institute Davos, Davos, Switzerland.
authors.forename: Boyko
authors.initials: B
authors.lastname: Gueorguiev
authors.affiliation: Department of Trauma Surgery, Regensburg University Medical Center, Davos, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Nerlich
authors.affiliation: Department of Trauma Surgery, Regensburg University Medical Center, Davos, Switzerland.
authors.forename: Carsten
authors.initials: C
authors.lastname: Neumann
authors.affiliation: Department of Trauma Surgery, Regensburg University Medical Center, Davos, Switzerland.
authors.forename: Florian
authors.initials: F
authors.lastname: Baumann
mesh_terms: D001863:Bone Screws; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000517:prevention & control; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D016103:Spinal Fractures / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries / Q000601:surgery; D016896:Treatment Outcome
keywords: internal fixators; lumbar spine; minimal-invasive surgery; outcome; reduction; spinal trauma; thoracic spine; vertebral body fracture