title: Is posterior percutaneous screw-rod instrumentation a safe and effective alternative approach to TLSO rigid bracing for single-level pyogenic spondylodiscitis? Results of a retrospective cohort analysis.
abstract: BACKGROUND
  Currently, treatment for patients diagnosed with noncomplicated (ie, known infectious agent, no neurologic compromise, and preserved spinal stability) pyogenic spondylodiscitis (PS) is based on intravenous antibiotics and rigid brace immobilization. Since January 2010, we started offering our patients percutaneous posterior screw-rod instrumentation as an alternative approach to rigid bracing. Supposed benefits of posterior percutaneous instrumentation over rigid bracing are earlier free mobilization, increased comfort, and faster recovery.
  
  
  OBJECTIVE
  To evaluate safety and effectiveness of posterior percutaneous spinal instrumentation for single-level PS and compare clinical and quality-of-life outcomes with standard thoracolumbosacral orthosis (TLSO) rigid bracing.
  
  
  METHODS
  Retrospective observational cohort study.
  
  
  METHODS
  Twenty-seven patients consecutively diagnosed with single-level noncomplicated lower thoracic or lumbar PS from January 2010 to December 2011.
  
  
  METHODS
  Healing rate, healing time, and changes in segmental kyphosis Cobb angle were compared in the two treatment groups. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and complete blood count at regular time points until complete healing were also obtained. Self-report measures included Visual Analog Scale (VAS), Short-Form 12 (SF-12), and EuroQol five-dimension (EQ-5D) questionnaires.
  
  
  METHODS
  At enrollment, patients were offered to choose between 24/7 TLSO rigid bracing for 3 to 4 months and bridging posterior percutaneous screw-rod instrumentation followed by soft bracing for 4 weeks after surgery. All patients underwent antibiotic therapy accordingly to isolated infectious agents. Patients were seen in the clinic at 1, 3, 6, and 9 months, and ESR, CRP, complete blood count, VAS, SF-12, and EQ-5D questionnaires were obtained. Segmental kyphosis was measured at diagnosis and at 9 months follow-up. Two-way repeated-measures analysis of variance was used to assess group and time differences across time points.
  
  
  RESULTS
  Fifteen patients chose conservative treatment, whereas 12 patients chose surgical treatment. Complete infection healing was achieved in all patients with no significant differences in healing time (p<.366). C-reactive protein and ESR levels decreased in both groups accordingly with positive response to therapy with no significant differences. Surgically treated patients had significantly lower VAS scores at 1 month (2.76±0.80 vs. 5.20±1.21, p<.001) and 3 months (2.31±0.54 vs. 2.85±0.54, p<.016) post-diagnosis over TLSO patients. Moreover, surgery patients also showed steeper and statistically significant improvements in SF-12 scores over TLSO patients at 1, 3, and 6 months post-diagnosis (p<.012); no significant differences were detected at the other time points. EuroQol five-dimension index was significantly higher in surgery patients at 1 month (0.764±0.043 vs. 0.458±0.197, p<.001) and 3 months (0.890±0.116 vs. 0.688±0.142, p<.001); no significant changes were observed in segmental pre- and posttreatment kyphosis between the two groups. No instrumentation-related complications were observed in any patient.
  
  
  CONCLUSIONS
  Posterior percutaneous spinal instrumentation is a safe, feasible, and effective procedure in relieving pain, preventing deformity, and neurologic compromise in patients affected by noncomplicated lower thoracic (T9-T12) or lumbar PS. Posterior instrumentation did not offer any advantage in healing time over TLSO rigid bracing because infection clearance is strongly dependent on proper antibiotic therapy. Nevertheless, surgical stabilization was associated with faster recovery, lower pain scores, and improved quality of life compared with TLSO conservative treatment at 1, 3, and 6 months after treatment.
authors.affiliation: Division of Spine Surgery, Department of Orthopaedics and Traumatology, Catholic University of Rome, "A. Gemelli" University Hospital, l.go Agostino Gemelli 8, 00168 Rome, Italy.
authors.forename: Luigi A
authors.initials: LA
authors.lastname: Nasto
authors.affiliation: Division of Spine Surgery, Department of Orthopaedics and Traumatology, Catholic University of Rome, "A. Gemelli" University Hospital, l.go Agostino Gemelli 8, 00168 Rome, Italy.
authors.forename: Debora
authors.initials: D
authors.lastname: Colangelo
authors.affiliation: Institute of Infectious Diseases, Catholic University of Rome, "A. Gemelli" University Hospital, l.go Agostino Gemelli 8, 00168 Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Mazzotta
authors.affiliation: Institute of Infectious Diseases, Catholic University of Rome, "A. Gemelli" University Hospital, l.go Agostino Gemelli 8, 00168 Rome, Italy.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Di Meco
authors.affiliation: Department of Medicine, Laboratory of Vascular Biology and Genetics, Catholic University of Rome, "A. Gemelli" University Hospital, l.go Agostino Gemelli 8, 00168 Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Neri
authors.affiliation: Department of Medicine, Laboratory of Vascular Biology and Genetics, Catholic University of Rome, "A. Gemelli" University Hospital, l.go Agostino Gemelli 8, 00168 Rome, Italy.
authors.forename: Riccardo A
authors.initials: RA
authors.lastname: Nasto
authors.affiliation: Institute of Infectious Diseases, Catholic University of Rome, "A. Gemelli" University Hospital, l.go Agostino Gemelli 8, 00168 Rome, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Fantoni
authors.affiliation: Division of Spine Surgery, Department of Orthopaedics and Traumatology, Catholic University of Rome, "A. Gemelli" University Hospital, l.go Agostino Gemelli 8, 00168 Rome, Italy. Electronic address: enrico.pola@rm.unicatt.it.
authors.forename: Enrico
authors.initials: E
authors.lastname: Pola
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001863:Bone Screws; D001915:Braces; D015331:Cohort Studies; D003131:Combined Modality Therapy; D015299:Discitis / Q000188:drug therapy / Q000601:surgery*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods*; D013904:Thoracic Vertebrae / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents
keywords: Minimally invasive surgery (MIS); Percutaneous screw-rod instrumentation; Pyogenic spondylodiscitis; Spinal infections; TLSO rigid bracing