title: Cantilever TLIF with structural allograft and RhBMP2 for correction and maintenance of segmental sagittal lordosis: long-term clinical, radiographic, and functional outcome.
abstract: METHODS
  Prospective cohort study in a tertiary care spine center.
  
  
  OBJECTIVE
  The effectiveness of the cantilever transforaminal lumbar interbody fusion (C-TLIF) technique in creating and maintaining lordosis, avoiding nerve problems, and obtaining fusion was studied.
  
  
  BACKGROUND
  C-TLIF is a microscope-assisted transforaminal lumbar interbody fusion technique, emphasizing no dural retraction with placement of structural allograft and RhBMP2 anteriorly under the cortical apophyseal ring, followed by middle column cancellous autograft placed under compression with posterior pedicle spinal instrumentation.
  
  
  METHODS
  A total of 100 consecutive patients studied with an average of 30 months of follow-up. A total of 48 had prior surgery at the index level; 16 had the procedure done at an adjacent level to a previous fusion; 32 at L5-S1 with 42 at L4-L5 and 26 at L3-L4. There were 76 single-level and 24 two-level fusions. One patient was a smoker with one other patient a compensation case. Outcome was prospectively documented with self-administered Visual Analog Pain Scale, Oswestry Disability Questionnaire, Treatment Intensity Questionnaire, and SF-36 Health Survey. Patients rated the surgery as excellent, good, fair, or poor and whether they would recommend the surgery. Student t test was used for statistical analysis with significance set at P = 0.05.
  
  
  RESULTS
  Blood loss and hospital stay averaged 300 mL and 2.2 days, respectively. There was significant reduction (P < 0.05) in pain scores from 9 to 3, Oswestry Disability Index scores from 35 to 12, and Treatment Intensity Score from 21/25 to 2/25 at final follow-up. The SF-36 PCS and MCS scores showed an increasing trend to improvement. A total of 69 rated the surgery as excellent, 23 good, 7 fair, and 1 poor. A total of 97% were satisfied and would recommend the surgery. All had improvement in radicular pain with no dural tears, neural injury, or neuropathic pain. There was significant improvement (P < 0.05) in segmental sagittal lordosis from 2 degrees to 9 degrees, anterior disc height from 6 to 14 mm, and posterior disc height from 4 to 8 mm. There was no subsidence, misplaced screws, or instrumentation failure. Solid fusion was obtained in 99 of 100 patients.
  
  
  CONCLUSIONS
  The C-TLIF allows for creation and maintenance of sagittal lordosis while avoiding subsidence and neurologic problems with a 99% fusion rate and 97% patient satisfaction.
authors.affiliation: Institute for Spinal Disorders, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA. anandn@cshs.org
authors.forename: Neel
authors.initials: N
authors.lastname: Anand
authors.forename: John F
authors.initials: JF
authors.lastname: Hamilton
authors.forename: Brian
authors.initials: B
authors.lastname: Perri
authors.forename: Hamid
authors.initials: H
authors.lastname: Miraliakbar
authors.forename: Theodore
authors.initials: T
authors.lastname: Goldstein
mesh_terms: D000328:Adult; D000368:Aged; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage*; D016025:Bone Transplantation; D015331:Cohort Studies; D003094:Collagen; D003131:Combined Modality Therapy; D004185:Disability Evaluation; D005260:Female; D006304:Health Status; D006801:Humans; D008141:Lordosis / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D010147:Pain Measurement; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000008:administration & dosage*; D012720:Severity of Illness Index; D013123:Spinal Fusion / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D015503:Surgical Sponges; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*; D014184:Transplantation, Homologous; D016896:Treatment Outcome
chemical_list: D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D003094:Collagen