title: Influence of postoperative sagittal balance and spinopelvic parameters on the outcome of patients surgically treated for degenerative lumbar spondylolisthesis.
abstract: OBJECTIVE The object of this study was to determine the association between postoperative sagittal spinopelvic alignment and patient-rated outcome measures following decompression and fusion for lumbar degenerative spondylolisthesis. METHODS The authors identified a consecutive series of patients who had undergone surgery for lumbar degenerative spondylolisthesis between 2008 and 2012, with an average follow-up of 3 years (range 1-6 years). Surgery was performed to address the clinical symptoms of spinal stenosis, not global sagittal alignment. Sagittal alignment was only assessed postoperatively. Patients were divided into 2 groups based on a postoperative sagittal vertical axis (SVA) < 50 mm (well aligned) or ≥ 50 mm (poorly aligned). Baseline demographic, procedure, and outcome measures were compared between the groups. Postoperative outcome measures and postoperative spinopelvic parameters were compared between groups using analysis of covariance. RESULTS Of the 84 patients included in this study, 46.4% had an SVA < 50 mm. Multiple levels of spondylolisthesis (p = 0.044), spondylolisthesis at the L3-4 level (p = 0.046), and multiple levels treated with fusion (p = 0.028) were more common among patients in the group with an SVA ≥ 50 mm. Patients with an SVA ≥ 50 mm had a worse SF-36 physical component summary (PCS) score (p = 0.018), a worse Oswestry Disability Index (ODI; p = 0.043), and more back pain (p = 0.039) than those with an SVA < 50 mm after controlling for multiple levels of spondylolisthesis and multilevel fusion. The spinopelvic parameters differing between the < 50-mm and ≥ 50-mm groups included lumbar lordosis (LL; 56.4° ± 4.7° vs 49.8° ± 4.3°, respectively, p = 0.040) and LL < pelvic incidence ± 9° (51% vs 23.1%, respectively, p = 0.013) after controlling for type of surgical procedure. CONCLUSIONS Data in this study revealed that patient-rated outcome is influenced by the overall postoperative sagittal balance as defined by the SVA.
authors.affiliation: Division of Orthopaedics, Department of Surgery, Schulich School of Medicine and Dentistry, Western University.|London Health Science Centre, London, Ontario, Canada.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Radovanovic
authors.affiliation: Lawson Health Research Institute; and.|London Health Science Centre, London, Ontario, Canada.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Urquhart
authors.affiliation: Division of Orthopaedics, Department of Surgery, Schulich School of Medicine and Dentistry, Western University.|London Health Science Centre, London, Ontario, Canada.
authors.forename: Venkat
authors.initials: V
authors.lastname: Ganapathy
authors.affiliation: Division of Orthopaedics, Department of Surgery, Schulich School of Medicine and Dentistry, Western University.|Lawson Health Research Institute; and.|London Health Science Centre, London, Ontario, Canada.
authors.forename: Fawaz
authors.initials: F
authors.lastname: Siddiqi
authors.affiliation: Division of Orthopaedics, Department of Surgery, Schulich School of Medicine and Dentistry, Western University.|Lawson Health Research Institute; and.|London Health Science Centre, London, Ontario, Canada.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Gurr
authors.affiliation: Division of Orthopaedics, Department of Surgery, Schulich School of Medicine and Dentistry, Western University.|Lawson Health Research Institute; and.|London Health Science Centre, London, Ontario, Canada.
authors.forename: Stewart I
authors.initials: SI
authors.lastname: Bailey
authors.affiliation: Division of Orthopaedics, Department of Surgery, Schulich School of Medicine and Dentistry, Western University.|Lawson Health Research Institute; and.|London Health Science Centre, London, Ontario, Canada.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Bailey
mesh_terms: D000368:Aged; D001416:Back Pain / Q000000981:diagnostic imaging / Q000601:surgery; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D010147:Pain Measurement; D010149:Postoperative Pain / Q000000981:diagnostic imaging; D010388:Pelvis / Q000000981:diagnostic imaging*; D011788:Quality of Life; D013123:Spinal Fusion / Q000009:adverse effects / Q000379:methods; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery; D013168:Spondylolisthesis / Q000000981:diagnostic imaging* / Q000601:surgery*; D016896:Treatment Outcome
keywords: HRQOL = health-related quality of life; ICC = intraclass correlation coefficient; LL = lumbar lordosis; MCS = mental component summary; NRS = numeric rating scale; ODI = Oswestry Disability Index; PCS = physical component summary; PI = pelvic incidence; PT = pelvic tilt; SS = sacral slope; SVA = sagittal vertical axis; TK = thoracic kyphosis; ZCQ = Zurich Claudication Questionnaire; degenerative lumbar spondylolisthesis; health-related quality of life; radiographic parameters; spinopelvic parameter; vertical sagittal balance