Abstract
Background and purpose - Indication for lumbar disc herniation (LDH) surgery is usually to relieve sciatica. We evaluated whether back pain also decreases after LDH surgery.Patients and methods - In the Swedish register for spinal surgery (SweSpine) we identified 14,097 patients aged 20-64 years, with pre- and postoperative data, who in 2000-2016 had LDH surgery. We calculated 1-year improvement on numeric rating scale (rating 0-10) in back pain (N(back)) and leg pain (N(leg)) and by negative binomial regression relative risk (RR) for gaining improvement exceeding minimum clinically important difference (MCID).Results - N(leg) was preoperatively (mean [SD]) 6.7 (2.5) and N(back) was 4.7 (2.9) (p < 0.001). Surgery reduced N(leg) by mean 4.5 (95% CI 4.5-4.6) and N(back) by 2.2 (CI 2.1-2.2). Mean reduction in N(leg)) was 67% and in N(back) 47% (p < 0.001). Among patients with preoperative pain ≥ MCID (that is, patients with significant baseline pain and with a theoretical possibility to improve above MCID), the proportion who reached improvement ≥ MCID was 79% in N(leg) and 60% in N(back). RR for gaining improvement ≥ MCID in smokers compared with non-smokers was for N(leg) 0.9 (CI 0.8-0.9) and -N(back) 0.9 (CI 0.8-0.9), and in patients with preoperative duration of back pain 0-3 months compared with > 24 months for N(leg) 1.3 (CI 1.2-1.5) and for N(back) 1.4 (CI 1.2-1.5).Interpretation - LDH surgery improves leg pain more than back pain; nevertheless, 60% of the patients with significant back pain improved ≥ MCID. Smoking and long duration of pain is associated with inferior recovery in both N(leg) and N(back).