Chronic osteoarthritis (OA) pain of the knee is often not effectively managed with current non-pharmacological or pharmacological treatments. Radiofrequency (RF) neurotomy is a therapeutic alternative for chronic pain. We investigated whether RF neurotomy applied to articular nerve branches (genicular nerves) was effective in relieving chronic OA knee joint pain. The study involved 38 elderly patients with (a) severe knee OA pain lasting more than 3 months, (b) positive response to a diagnostic genicular nerve block and (c) no response to conservative treatments. Patients were randomly assigned to receive percutaneous RF genicular neurotomy under fluoroscopic guidance (RF group; n=19) or the same procedure without effective neurotomy (control group; n=19). Visual analogue scale (VAS), Oxford knee scores, and global perceived effect on a 7-point scale were measured at baseline and at 1, 4, and 12weeks post-procedure. VAS scores showed that the RF group had less knee joint pain at 4 (p<0.001) and 12 (p<0.001) weeks compared with the control group. Oxford knee scores showed similar findings (p<0.001). In the RF group, 10/17 (59%), 11/17 (65%) and 10/17 (59%) achieved at least 50% knee pain relief at 1, 4, and 12 weeks, respectively. No patient reported a post-procedure adverse event during the follow-up period. RF neurotomy of genicular nerves leads to significant pain reduction and functional improvement in a subset of elderly chronic knee OA pain, and thus may be an effective treatment in such cases. Further trials with larger sample size and longer follow-up are warranted.

Redundant nerve root syndrome (RNRS) is a phenomenon characterized by the presence of elongated, enlarged, tortuous nerve roots in the lumbar subarachnoid space. It is unclear whether RNRS is caused by spinal stenosis or causes these symptoms.This study evaluated the effects of lumbar epidural steroid injection (LESI) on patients with RNRS and assessed factors associated with RNRS. This retrospective observational cohort study was conducted at a single pain clinic of a university hospital.The medical records of 172 outpatients presenting with low back and/or leg pain from July to December 2014 were analyzed. Pain intensity (numeric rating scale [NRS]) and functional status were assessed at baseline and 2, 4, and 12 weeks after the LESI. Patients were considered moderate responders if they showed a 3-point or >30% reduction in baseline NRS, or said “better than 30%,” “a little better,” or “I feel an effect.” Patients were considered substantial responders if they showed a 5-point or >50% reduction in baseline NRS, or said “better than 50%,” “very good,” or “much better.” Generalized estimating equation (GEE) analysis was performed to identify the factors associated with moderate response to LESI. Factors associated with RNRS were also determined by logistic regression analysis.The proportions of both moderate and substantial responders at 2, 4, and 12 weeks were significantly lower in patients with than without RNRS. GEE analysis showed that RNRS were the only factor significantly associated with moderate response to LESI (OR = 0.400; 95% CI, 0.253–0.632; P < .001). The distance from the conus medullaris to the closest level of stenosis was shorter in patients with than without RNRS (P < .001) and was the only independent factor associated with RNRS on multivariate logistic regression analysis (OR = 0.972; P < .001).LESI was less effective in patients with than without RNRS. The only independent factor significantly associated with RNRS was the distance from the conus medullaris to the nearest moderate stenosis.

Smoking is clinically associated with high postoperative pain scores and increased perioperative analgesic requirements. However, the association between the duration of smoking cessation and postoperative opioid requirements remains unclear. Therefore, this study aimed to evaluate the association between the duration of smoking cessation and postoperative opioid requirements. We retrospectively analyzed the data of 144 male patients who received intravenous patient-controlled analgesia (IV PCA) after laparoscopic distal gastrectomy with gastroduodenostomy. All patients were divided into three groups: G0, nonsmoker; G1, smoker who quit smoking within 1 month preoperatively; G2, smoker who quit smoking over 1 month preoperatively. Analgesic use, pain intensity, and IV PCA side effects were assessed up to postoperative day 2. As the duration of smoking cessation increased, the amount of postoperative opioid consumption decreased (β = −0.08; 95% confidence interval (CI), −0.11 to −0.04; P < 0.001 ). The total postoperative opioid requirements in G1 were significantly higher than those in G0 and G2 (G0, 75.5 ± 15.9 mg; G1, 94.6 ± 20.5 mg; and G2, 79.9 ± 19.4 mg P < 0.001 ). A multivariate regression analysis revealed that G1 was independently associated with increased postoperative opioid requirements (β = 12.80; 95% CI, 5.81–19.80; P < 0.001 ). Consequently, male patients who had ceased smoking within 1 month of undergoing a laparoscopic distal gastrectomy with gastroduodenostomy had higher postoperative opioid use than patients who had ceased smoking for more than 1 month and nonsmokers.