ACB results in greater preservation of quadriceps muscle strength. Although we did not detect a significant reduction in fall risk when compared with FNB, based on the upper limit of the relative risk, it may very well be present. Further study is needed with a larger sample size.

Background and objectivesPeripheral nerve blocks have been integrated into most multimodal analgesia protocols for total knee arthroplasty (TKA). The adductor canal block (ACB) has gained popularity because of its quadriceps muscle sparing. Similarly, local anesthetic injection between the popliteal artery and the posterior capsule of the knee, IPACK block, has been described to provide analgesia to the posterior capsule of the knee with motor-sparing qualities. This prospective randomized controlled trial aimed to assess the analgesic efficacy of adding the IPACK block to our current multimodal analgesic regimen, including the ACB, in patients undergoing primary TKA.Methods119 patients were randomized to receive either an IPACK or a sham block in addition to multimodal analgesia and an ACB. We were set to assess pain in the back of the knee 6 hours after surgery. Other end points included quality of recovery after surgery, pain scores, opioid requirements, and functional measures.ResultsPatients who received the IPACK block had less pain in the back of the knee 6 hours after surgery when compared with the sham block: 21.7% vs 45.8%, p<0.01. There was marginal improvement in other pain measures in the first 24 hours after surgery. However, opioid requirements, quality of recovery and functional measures were similar between the two groups.ConclusionThe IPACK block reduced the incidence of posterior knee pain 6 hours postoperatively.

Background: Safe and effective non-surgical treatments are an important part of the knee osteoarthritis (OA) treatment algorithm. Cooled radiofrequency ablation (CRFA) and hyaluronic acid (HA) injections are two commonly used modalities to manage symptoms associated with knee OA. Methods: A prospective 1:1 randomized study was conducted in 177 patients comparing CRFA to HA injection with follow-ups at 1, 3, 6 and 12 months. HA subjects with unsatisfactory outcomes at 6-months were allowed to crossover and receive CRFA. Knee pain (numeric rating scale = NRS), WOMAC Index (pain, stiffness and physical function), overall quality of life (global perceived effect = GPE, EQ-5D-5 L), and adverse events were measured. Results: At 12-months, 65.2% of subjects in the CRFA cohort reported ≥50% pain relief from baseline. Mean NRS pain score was 2.8 ± 2.4 at 12 months (baseline 6.9 ± 0.8). Subjects in the CRFA cohort saw a 46.2% improvement in total WOMAC score at the 12-month timepoint. 64.5% of subjects in the crossover cohort reported ≥50% pain relief from baseline, with a mean NRS pain score of 3.0 ± 2.4 at 12 months (baseline 7.0 ± 1.0). After receiving CRFA, subjects in the crossover cohort had a 27.5% improvement in total WOMAC score. All subjects receiving CRFA reported significant improvement in quality of life. There were no serious adverse events related to either procedure and overall adverse event profiles were similar.

Aims Adductor canal block (ACB) has emerged as an alternative to femoral nerve block (FNB) for analgesia after total knee arthroplasty (TKA). The optimal duration of maintenance of the ACB is still questionable. The purpose of this study was to compare the analgesic benefits and physiotherapy (PT) outcomes of single-shot ACB to two different regimens of infusion of the continuous ACB, 24-hour and 48-hour infusion. Patients and Methods This was a prospective, randomized, unblinded study. A total of 159 American Society of Anesthesiologists (ASA) physical status I to III patients scheduled for primary TKA were randomized to one of three study groups. Three patients did not complete the study, leaving 156 patients for final analysis. Group A (n = 53) was the single-shot group (16 female patients and 37 male patients with a mean age of 63.9 years (sd 9.6)), group B (n = 51) was the 24-hour infusion group (22 female patients and 29 male patients with a mean age of 66.5 years (sd 8.5)), and group C (n = 52) was the 48-hour infusion group (18 female patients and 34 male patients with a mean age of 62.2 years (sd 8.7)). Pain scores, opioid requirements, PT test results, and patient-reported outcome instruments were compared between the three groups. Results The proportion of patients reporting severe pain, defined as a pain score of between 7 and 10, on postoperative day number 2 (POD 2) were 21% for the single-shot group, 14% for the 24-hour block group, and 12% for the 48-hour block group (p = 0.05). Cumulative opioid requirements after 48 hours were similar between the groups. Functional outcomes were similar in all three groups in POD 1 and POD 2. Conclusion There was no clear benefit of the 24-hour or 48-hour infusions over the single-shot ACB for the primary endpoint of the study. Otherwise, there were marginal benefits for keeping the indwelling catheter for 48 hours in terms of reducing the number of patients with moderate pain and improving the quality of pain management. However, all three groups had similar opioid usage, length of hospital stay, and functional outcomes. Further studies with larger sample sizes are needed to confirm these findings. Cite this article: Bone Joint J 2019;101-B:340–347.

Background: Knee osteoarthritis is a painful and sometimes debilitating disease that often affects patients for years. Current treatments include short-lasting and often repetitive nonsurgical options, followed by surgical intervention for appropriate candidates. Cooled radiofrequency ablation (CRFA) is a minimally invasive procedure for the treatment of pain related to knee osteoarthritis. This trial compared the efficacy and safety of CRFA with those of a single hyaluronic acid (HA) injection. Methods: Two hundred and sixty subjects with knee osteoarthritis pain that was inadequately responsive to prior nonoperative modalities were screened for enrollment in this multicenter, randomized trial. One hundred and eighty-two subjects who met the inclusion criteria underwent diagnostic block injections and those with a minimum of 50% pain relief were randomized to receive either CRFA on 4 genicular nerves or a single HA injection. One hundred and seventy-five subjects were treated (88 with CRFA and 87 with HA). Evaluations for pain (Numeric Rating Scale [NRS]), function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), quality of life (Global Perceived Effect [GPE] score and EuroQol-5 Dimensions-5 Level [EQ-5D-5L] questionnaire), and safety were performed at 1, 3, and 6 months after treatment. Results: Demographic characteristics did not differ significantly between the 2 study groups. A total of 158 subjects (76 in the CRFA group and 82 in the HA group) completed the 6-month post-treatment follow-up. In the CRFA group, 71% of the subjects had ≥50% reduction in the NRS pain score (primary end point) compared with 38% in the HA group (p < 0.0001). At 6 months, the mean NRS score reduction was 4.1 ± 2.2 for the CRFA group compared with 2.5 ± 2.5 for the HA group (p < 0.0001). The mean WOMAC score improvement at 6 months from baseline was 48.2% in the CRFA group and 22.6% in the HA group (p < 0.0001). At 6 months, 72% of the subjects in the CRFA group reported improvement in the GPE score compared with 40% in the HA group (p < 0.0001). Conclusions: CRFA-treated subjects demonstrated a significant improvement in pain relief and overall function compared with subjects treated with a single injection of HA. No serious adverse events related to either procedure were noted, and the overall adverse-event profiles were similar. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.