title: Clinical outcomes following spinal fusion using an intraoperative computed tomographic 3D imaging system.
abstract: OBJECTIVE Improvements in imaging technology have steadily advanced surgical approaches. Within the field of spine surgery, assistance from the O-arm Multidimensional Surgical Imaging System has been established to yield superior accuracy of pedicle screw insertion compared with freehand and fluoroscopic approaches. Despite this evidence, no studies have investigated the clinical relevance associated with increased accuracy. Accordingly, the objective of this study was to investigate the clinical outcomes following thoracolumbar spinal fusion associated with O-arm-assisted navigation. The authors hypothesized that increased accuracy achieved with O-arm-assisted navigation decreases the rate of reoperation secondary to reduced hardware failure and screw misplacement. METHODS A consecutive retrospective review of all patients who underwent open thoracolumbar spinal fusion at a single tertiary-care institution between December 2012 and December 2014 was conducted. Outcomes assessed included operative time, length of hospital stay, and rates of readmission and reoperation. Mixed-effects Cox proportional hazards modeling, with surgeon as a random effect, was used to investigate the association between O-arm-assisted navigation and postoperative outcomes. RESULTS Among 1208 procedures, 614 were performed with O-arm-assisted navigation, 356 using freehand techniques, and 238 using fluoroscopic guidance. The most common indication for surgery was spondylolisthesis (56.2%), and most patients underwent a posterolateral fusion only (59.4%). Although O-arm procedures involved more vertebral levels compared with the combined freehand/fluoroscopy cohort (4.79 vs 4.26 vertebral levels; p < 0.01), no significant differences in operative time were observed (4.40 vs 4.30 hours; p = 0.38). Patients who underwent an O-arm procedure experienced shorter hospital stays (4.72 vs 5.43 days; p < 0.01). O-arm-assisted navigation trended toward predicting decreased risk of spine-related readmission (0.8% vs 2.2%, risk ratio [RR] 0.37; p = 0.05) and overall readmissions (4.9% vs 7.4%, RR 0.66; p = 0.07). The O-arm was significantly associated with decreased risk of reoperation for hardware failure (2.9% vs 5.9%, RR 0.50; p = 0.01), screw misplacement (1.6% vs 4.2%, RR 0.39; p < 0.01), and all-cause reoperation (5.2% vs 10.9%, RR 0.48; p < 0.01). Mixed-effects Cox proportional hazards modeling revealed that O-arm-assisted navigation was a significant predictor of decreased risk of reoperation (HR 0.49; p < 0.01). The protective effect of O-arm-assisted navigation against reoperation was durable in subset analysis of procedures involving < 5 vertebral levels (HR 0.44; p = 0.01) and ≥ 5 levels (HR 0.48; p = 0.03). Further subset analysis demonstrated that O-arm-assisted navigation predicted decreased risk of reoperation among patients undergoing posterolateral fusion only (HR 0.39; p < 0.01) and anterior lumbar interbody fusion (HR 0.22; p = 0.03), but not posterior/transforaminal lumbar interbody fusion. CONCLUSIONS To the authors' knowledge, the present study is the first to investigate clinical outcomes associated with O-arm-assisted navigation following thoracolumbar spinal fusion. O-arm-assisted navigation decreased the risk of reoperation to less than half the risk associated with freehand and fluoroscopic approaches. Future randomized controlled trials to corroborate the findings of the present study are warranted.
authors.affiliation: Cleveland Clinic Center for Spine Health and.|Cleveland Clinic Lerner College of Medicine.
authors.forename: Roy
authors.initials: R
authors.lastname: Xiao
authors.affiliation: Cleveland Clinic Center for Spine Health and.|Cleveland Clinic Lerner College of Medicine.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Miller
authors.affiliation: Cleveland Clinic Center for Spine Health and.|Cleveland Clinic Lerner College of Medicine.
authors.forename: Navin C
authors.initials: NC
authors.lastname: Sabharwal
authors.affiliation: Department of Neurological Surgery, Johns Hopkins Hospital, Baltimore, Maryland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Lubelski
authors.affiliation: Cleveland Clinic Center for Spine Health and.|Case Western Reserve University School of Medicine, Cleveland, Ohio; and.
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Alentado
authors.affiliation: Cleveland Clinic Center for Spine Health and.|Department of Neurological Surgery, Cleveland Clinic.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Healy
authors.affiliation: Cleveland Clinic Center for Spine Health and.|Department of Neurological Surgery, Cleveland Clinic.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Mroz
authors.affiliation: Cleveland Clinic Center for Spine Health and.|Department of Neurological Surgery, Cleveland Clinic.
authors.forename: Edward C
authors.initials: EC
authors.lastname: Benzel
mesh_terms: D001863:Bone Screws; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D021621:Imaging, Three-Dimensional; D053208:Kaplan-Meier Estimate; D007902:Length of Stay; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D019300:Medical Errors; D008875:Middle Aged; D061646:Operative Time; D010359:Patient Readmission; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D013123:Spinal Fusion; D025321:Surgery, Computer-Assisted; D013904:Thoracic Vertebrae / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: ALIF = anterior lumbar interbody fusion; BMI = body mass index; CCI = Charlson Comorbidity Index; ED = emergency department; O-arm; PLIF = posterior lumbar interbody fusion; RR = risk ratio; SSI = surgical-site infection; TLIF = transforaminal lumbar interbody fusion; multivariable regression; navigation; pedicle screw; reoperation; spinal fusion; surgical technique