Factors Associated With Clinical Outcomes After Lumbar Interbody Fusion With a Porous Nitinol Implant

Abstract

Study Design:A retrospective cohort study.Objective:The aim of this study is to assess the association of demographic and perioperative factors with clinical outcomes of lumbar interbody fusion with a porous nitinol (TiNi) implant for degenerative disc disease.Methods:Forty-one patients with degenerative lumbar disease were prospectively followed for a mean of 4.8 years. All patients were instrumented with porous TiNi interbody fusion devices. The Oswestry Disability Index (ODI) and return to work were used to assess clinical outcomes. Factors including age, body mass index, smoking status, insurance status, number of comorbidities, duration of surgery, estimated blood loss, number of levels fused, time since surgery, and preoperative ODI score were assessed. A multiple linear regression analysis was performed to look for demographic and perioperative factors associated with clinical outcome.Results:All patients except one (98%) showed complete fusion on radiography at 1 year. Estimated blood loss and duration of surgery were significantly associated with higher postoperative ODI scores (P = .002 and P = .019, respectively). Smoking status, salary insurance status, age, body mass index, number of comorbidities, number of levels fused, time since surgery, and preoperative ODI score were not significantly associated with outcome.Conclusions:Porous nitinol permitted fusion rates similar to those reported in the literature for alternative fusion cages. Poor functional outcome of patients was strongly associated with intraoperative blood loss and duration of surgery. We believe that estimated blood loss should be carefully evaluated in studies of postoperative outcome, as it may affect midterm outcomes.Level of Evidence:Level 3

Assessment of Functional Outcome Predictors in Patients Undergoing Lumbar Interbody Fusion Surgery: A Single-Centre Analysis

“…Factors such as age, body mass index, and medical comorbidities do not affect the functional outcome in our study. These conclusions are in accordance with data reported by other authors [ 13 - 15 ]. In our population, there were only two smokers, which limits this specific analysis.…”

“…In our cohort, patients undergoing TLIF and PLIF had similar results supporting the previously published claims. Although our study does not show an impact of surgical complications in the ODI quantification, Abduljabbar et al show a correlation between blood loss and worse functional outcomes [ 13 ]. We did not observe this, probably due to the limited number of surgical complications.…”

“…Most variables related to the surgery, such as type of interbody fusion performed, segments intervened, and duration of post-surgery hospitalization, do not influence the functional outcome in our cohort, as also reported by others [ 13 , 20 ]. Srikanth et al and Mobbs et al [ 1 , 20 ] both report that the type of surgery does not impact the outcome, so the surgical approach is done according to advantages, disadvantages, and limitations at the surgical level tailored for each patient.…”

“…Noteworthy, our results suggest that a worse dysfunction before surgery predicts a greater improvement after the intervention, as patients that were significantly impaired at the time of referral, benefited the most from surgery. Although one study reported that pre-surgery ODI does not correlate with functional outcome [ 13 ], patients with higher ODI scores appear to improve more with interbody lumbar fusion in another work [ 21 ]. Therefore, patients with severe deterioration of functional status before intervention appear to be good candidates for interbody lumbar fusion.…”

Commentary on “Biomaterials in Spinal Implants: A Review”

“…A single retrospective cohort study indicates similar fusion rates with TiNi implant for lumbar surgeries compared with alternative cages. 10 Bio-absorbable cages are another generation of cages which can avoid artefacts on scans, reduce long term toxicity. The clinical studies support the use of bioabsorbable interbody devices for structural support.…”