title: Surgical treatment of low-grade isthmic spondylolisthesis with transsacral fibular strut grafts.
abstract: BACKGROUND
  The ideal surgical treatment for adult low-grade isthmic spondylolisthesis (ALIS) remains unknown. Isolated anterior and posterior procedures are popular but have resulted in equivocal outcomes, whereas combined anterior and posterior procedures are associated with higher complication rates despite improved outcome.
  
  
  OBJECTIVE
  To evaluate the clinical and radiographic outcomes following the treatment of ALIS using a 1-stage posterior approach with posterior decompression and posterolateral arthrodesis combined with an interbody fibular allograft strut.
  
  
  METHODS
  Fifteen patients underwent fusion by a single surgeon using our modified technique. Seven patients were female and 8 were male, with a mean age of 48 years. All patients were classified as Meyerding grade II slips and underwent a posterior approach only, a decompressive laminectomy, and a circumferential fusion with the use of a transsacral fibular allograft and a posterolateral instrumented fusion. Postoperative clinical and radiographic evaluations were performed at 3, 6, and 12 months, and then on an annual basis.
  
  
  RESULTS
  The average follow-up interval was 61 months. Three complications were seen: a single dural tear, an L5 radiculopathy secondary to a malpositioned pedicle screw, and one patient with urinary retention. The spines of all patients were determined to be fused by the 6-month postoperative visit. All patients returned to their normal activities of daily living. Significant improvements in the visual analog score were seen at all follow-up intervals.
  
  
  CONCLUSIONS
  Transsacral interbody fibular allograft can be used successfully to supplement a posterolateral instrumented fusion in selected patients with low-grade ALIS.
authors.affiliation: Division of Spine Surgery, Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. panagmd@gmail.com
authors.forename: Peter G
authors.initials: PG
authors.lastname: Passias
authors.forename: Michal
authors.initials: M
authors.lastname: Kozanek
authors.forename: Kirkham B
authors.initials: KB
authors.lastname: Wood
mesh_terms: D000328:Adult; D016025:Bone Transplantation / Q000379:methods*; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D005360:Fibula / Q000637:transplantation*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012720:Severity of Illness Index; D013123:Spinal Fusion / Q000379:methods*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome