Analysis of risk factors and postoperative predictors for recurrent lumbar disc herniation

Original Article Analysis of risk factors and postoperative predictors for recurrent lumbar disc herniation M. Dobran, Davide Nasi, R. Paracino, M. Gladi, M. Della Costanza, A. Marini, S. Lattanzi, M. Iacoangeli Department of Neurosurgery, Umberto I General Hospital, Università Politecnica delle Marche, Ancona, Italy. E-mail: M. Dobran - dobran@libero.it; *Davide Nasi - davidenasi83@gmail.com; R. Paracino - r.paracino@gmail.com; M. Gladi - mauriziogladi@gmail.com; M. Della Costanza - martina.dellacostanza@gmail.com; A. Marini - marini.alessandra.am@tiscali.it; S. Lattanzi - alfierelattanzisimona@gmail.com; M. Iacoangeli - neurotra@gmail.com ABSTRACT Background: This study identified risk factors and postoperative indicators for recurrent lumbar disc herniations (rLDH) following microdiscectomy. Methods: We retrospectively reviewed the 1-year recurrence rate for LDH in 209 consecutive patients undergoing microdiscectomy (2013–2018). Results: Utilizing a multivariate analysis, higher body mass index (BMI) and postsurgery Oswestry disability index (ODI) were significantly associated with an increased risk of rLDH. Conclusions: Elevated postsurgery ODI and higher BMI were significantly associated with increased risk of rLDH. Keywords: Discectomy, lumbar disc herniation, lumbar microdiscectomy, recurrent disc herniation *Corresponding author: Davide Nasi, Department of Neurosurgery, Università Politecnica delle Marche - Ospedali Riuniti, Via Conca #71, Ancona - 60020, Italy. davidenasi83@gmail.com Received : 13 January 19 Accepted : 18 January 19 Published : 26 March 19 DOI 10.25259/SNI-22-2019 Quick Response Code: INTRODUCTION Lumbar disc herniation (LDH) is the most common reason for performing lumbar spine surgery. Today, many are managed utilizing a microdiscectomy approach. Nevertheless, these procedures correlate with a recurrence rate at 1 year that ranges from 1% to 21%.[1,3,5] Here, we looked at potential risk factors that may contribute to recurrent LDH (rLDH) following microdiscectomy. MATERIALS AND METHODS We retrospectively reviewed consecutive patients who underwent standard lumbar spinal microdiscectomy for disc herniation (LDH) (2013–2018). The follow-up evaluations were performed at 1, 6, and 12 months postoperatively. Recurrence of disc herniation was defined as disc herniation at the same level and side of the previous microdiscectomy after a 3-month postoperative pain-free www.surgicalneurologyint.com Surgical Neurology International Editor-in-Chief: Nancy E. Epstein, MD, NYU Winthrop Hospital, Mineola, NY, USA. SNI: Spine Editor Nancy E. Epstein, MD NYU Winthrop Hospital, Mineola, NY, USAOpen Access Dobran, et al.: Predictors for recurrent lumbar disc herniation Surgical Neurology International • 2019 • 10(36) | 2 period. Variables contributing to rLDH included age, sex, weight/body mass index (BMI), smoking status, postoperative (6 months) Oswestry disability index (ODI), and the level of the disc herniation. Radiological examination included magnetic resonance imaging before and after surgery. Statistical analysis Analyses include Student’s t-test, Mann–Whitney U-test or Chi-squared test, logistic regression, and multivariate analysis. Results were considered significant for P < 0.05 (two-sided). Data analysis was performed using STATA/IC 13.1 statistical package (StataCorp LP, Texas, USA). RESULTS There were 209 patients included in this study; 20 of 209 (9.6%) had rLDH at 1 postoperative year. Utilizing a multivariate analysis, older age, higher BMI, and postsurgery ODI were significantly associated with increased risk of rLDH [Tables 1 and 2]. DISCUSSION Microdiscectomy is a relatively straightforward procedure but is associated with a complication rate of up to 15–18%.[1-6] rLDH is the most frequent complication, occurring from 5% to 15% of the time.[6] rLDH is defined as a disc hernia at the same level of a previous microdiscectomy in patient with a pain-free interval of at least 3 months long after surgery.[1-6] In patients treated with microdiscectomy, it is important to avoid a second surgery due to the attendant increased risks/complications associated with repeated decompression versus decompression/ fusion.[5,6] In our study, BMI was an independent predictor of recurrence both at unadjusted logistic regression analysis (P = 0.004) and adjusted analysis (P = 0.024). In our series, postoperative 6-month ODI score value correlated with rLDH. Furthermore, in this study, older age was a predictor of recurrence.[1-6] CONCLUSIONS To summarize, patients with rLDH were older and had higher BMI and postsurgery ODI score after a pain-free 3-month interval. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. REFERENCES 1. Ambrossi GL, McGirt MJ, Sciubba DM, Witham TF, Wolinsky JP, Gokaslan ZL, et al. Recurrent lumbar disc herniation after singlelevel lumbar discectomy: Incidence and health care cost analysis. Neurosurgery 2009;65:574-8. 2. Dobran M, Brancorsini D, Costanza MD, Liverotti V, Mancini F, Nasi D, et al. Epidural scarring after lumbar disc surgery: Equivalent scarring with/without free autologous fat grafts. Surg Neurol Int 2017;8:169. 3. Dobran M, Marini A, Gladi M, Nasi D, Colasanti R, Benigni R, et al. Deep spinal infection in instrumented spinal surgery: Diagnostic factors and therapy. G Chir 2017;38:124-9. Table 1: Characteristics of patients according to 1‑year outcome; relapse: n=20 (9.6%). Variable Full cohort (n=209) No relapse (n=189) Relapse (n=20) P Age (years) 44.6 (11.8) 43.9 (11.7) 50.4 (12.0) 0.021a Male sex 125 (59.8) 115 (60.9) 10 (50.0) 0.347b BMI (kg/m2) 27 (24–20) 27 (24–28) 29 (27.5–30.5) 0.005c Smoking 144 (68.9) 129 (68.3) 15 (75.0) 0.535b VAS 2.6 (1.5) 2.5 (1.5) 3.2 (1.7) 0.076a ODI 15 (10–20) 15 (5–20) 20 (15–22) 0.002c Disc hernia level ‑ ‑ 3 (8.6) 0.973b L3–L4 35 (16.8) 32 (91.4) 10 (9.6) ‑ L4–L5 104 (49.8) 94 (90.4) 7 (10.0) ‑ L5–S1 70 (33.5) 63 (90.0) ‑ ‑ Data are mean (SD) or median (IQR) for continuous variables and n (%) for categorical variables. aTwo‑sample t‑test. bChi‑squared test. cMann–Whitney U‑test. ODI: Oswestry disability index; VAS: Visual analog scale, BMI: Body mass index, SD: Standard deviation Table 2: Prediction of 1‑year LDH. Independent variable Unadjusted Adjusted* OR (95% CI) P OR (95% CI) P Age 1.05 (1.01–1.09) 0.023 1.04 (1.00–1.09) 0.060 Sex 0.64 (0.26–1.62) 0.350 0.50 (0.18–1.38) 0.178 BMI 1.28 (1.08–1.51) 0.004 1.23 (1.03–1.46) 0.022 Smoking 1.40 (0.48–4.02) 0.537 0.98 (0.30–3.13) 0.968 ODI 1.10 (1.03–1.17) 0.005 1.09 (1.02–1.18) 0.017 Disc hernia level 1.08 (0.55–2.12) 0.824 0.88 (0.41–1.88) 0.740 ORs for every 1 year and 1‑point BMI or ODI increases are obtained with logistic regression analysis. BMI: Body mass index; CI: Confidence interval; ODI: Oswestry disability index; OR: Odds ratio, LDH: Lumbar disc herniation Dobran, et al.: Predictors for recurrent lumbar disc herniation Surgical Neurology International • 2019 • 10(36) | 3 4. Dobran M, Marini A, Nasi D, Gladi M, Liverotti V, Costanza MD, et al. Risk factors of surgical site infections in instrumented spine surgery. Surg Neurol Int 2017;8:212. 5. Huang W, Han Z, Liu J, Yu L, Yu X. Risk factors for recurrent lumbar disc herniation: A systematic review and meta-analysis. Medicine (Baltimore) 2016;95:e2378. 6. Meredith DS, Huang RC, Nguyen J, Lyman S. Obesity increases the risk of recurrent herniated nucleus pulposus after lumbar microdiscectomy. Spine J 2010;10:575-80. How to cite this article: Dobran M, Nasi D, Paracino R, Gladi M, Costanza MD, Marini A, et al. Analysis of risk factors and postoperative predictors for recurrent lumbar disc herniation. Surg Neurol Int 2019:10:36.