title: Preoperative estimation of disc herniation recurrence after microdiscectomy: predictive value of a multivariate model based on radiographic parameters.
abstract: Recurrence of lumbar disc herniation (rLDH) is one of the unfavorable outcomes after microdiscectomy. Prediction of the patient population with increased risk of rLDH is important because patients may benefit from preventive measures or other surgical options.
  
  
  
  The study assessed preoperative factors associated with rLDH after microdiscectomy and created a mathematical model for estimation of chances for rLDH.
  
  
  
  This is a retrospective case-control study.
  
  
  
  The study includes patients who underwent microdiscectomy for LDH.
  
  
  
  Lumbar disc herniation recurrence was determined using magnetic resonance imaging.
  
  
  
  The study included 350 patients with LDH and a minimum of 3 years of follow-up. Patients underwent microdiscectomy for LDH at the L4-L5 and L5-S1 levels from 2008 to 2012. Patients were divided into two groups to identify predictors of recurrence: those who developed rLDH (n=50) within 3 years and those who did not develop rLDH (n=300) within the same follow-up period. Multivariate analysis was performed using patient baseline clinical and radiography data. Non-linear, multivariate, logistic regression analysis was used to build a predictive model.
  
  
  
  Recurrence of LDH occurred within 1 to 48 months after microdiscectomy. Preoperatively, patients who developed rLDH were smokers (70% vs. 27%, p<.01; odds ratio [OR]=6.31, 95% confidence interval [CI]: 3.27-12.16) and had higher body mass index (29.0±6.1 vs. 27.0±4.3, p=.03; OR=1.09 per 0.01 unit change). Radiological parameters that were associated with rLDH were higher disc height index (0.35±0.007 vs. 0.26±0.002, p<.001), higher segmental range of motion (9.8±0.28° vs. 7.6±0.11°, p<.001; OR=0.53 per 0.01 unit change), and lower central angle of lumbar lordosis (33.4±0.81° vs. 47.1±0.47°, p<.001; OR=0.53 per 0.01 unit change). Additionally, Pfirrmann grade 3 (OR=16.62, 95% CI: 8.10-34.11), protrusion type of LDH (OR=5.90, 95% CI: 3.06-11.36), and Grogan sclerosis grades 3 and 4 (OR=4.81, 95% CI: 2.50-9.22) were also associated with rLDH. Multivariate non-linear modeling allowed for more accurate prediction of rLDH (90% correct prediction of rLDH; 99% correct prediction of no rLDH) than other univariate logit models.
  
  
  
  Preoperative radiographic parameters in patients with LDH can be used to assess the risk of recurrence after microdiscectomy. The multifactorial non-linear model provided more accurate rLDH probability estimation than the univariate analyses. The software developed from this model may be implemented during patient counseling or decision making when choosing the type of primary surgery for LDH.
authors.affiliation: Irkutsk Scientific Center of Surgery and Traumatology, Bortsov Revolyutsii str., 1, Irkutsk, 664003, Russia; Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W. Thomas Rd, Phoenix, AZ 85013, USA; Department of Neurosurgery, Irkutsk State Medical University, Krasnogo vosstaniya str., 1, Irkutsk, 664003, Russia.
authors.forename: Evgenii
authors.initials: E
authors.lastname: Belykh
authors.affiliation: Neurosurgery Department No. 2, Novosibirsk Scientific Research Institute of Traumatology and Orthopedics, Frunze str., 17, Novosibirsk, 630091, Russia.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Krutko
authors.affiliation: Neurosurgery Department No. 2, Novosibirsk Scientific Research Institute of Traumatology and Orthopedics, Frunze str., 17, Novosibirsk, 630091, Russia.
authors.forename: Evgenii S
authors.initials: ES
authors.lastname: Baykov
authors.affiliation: Irkutsk Scientific Center of Surgery and Traumatology, Bortsov Revolyutsii str., 1, Irkutsk, 664003, Russia; Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W. Thomas Rd, Phoenix, AZ 85013, USA.
authors.forename: Morgan B
authors.initials: MB
authors.lastname: Giers
authors.affiliation: Irkutsk Scientific Center of Surgery and Traumatology, Bortsov Revolyutsii str., 1, Irkutsk, 664003, Russia; Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W. Thomas Rd, Phoenix, AZ 85013, USA.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Preul
authors.affiliation: Irkutsk Scientific Center of Surgery and Traumatology, Bortsov Revolyutsii str., 1, Irkutsk, 664003, Russia; Department of Neurosurgery, Irkutsk State Medical University, Krasnogo vosstaniya str., 1, Irkutsk, 664003, Russia; Neurosurgery Department, Irkutsk Railway Clinical Hospital, Botkina str, 10, Irkutsk, 664005, Russia. Electronic address: Neuropub@dignityhealth.org.
authors.forename: Vadim A
authors.initials: VA
authors.lastname: Byvaltsev
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D017586:Diskectomy / Q000379:methods*; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D057234:Preoperative Period; D011859:Radiography; D016059:Range of Motion, Articular; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment
keywords: Complications; Intervertebral disc degeneration; Intervertebral disc displacement; Prevention; Radiography; Statistics; Surgery