Turlough O Hare, MD, FRCPC, MSc Assistant Clinical Professor, Department of Anesthesia, St. Joseph s Healthcare Hamilton McMaster University

Turlough O Hare, MD, FRCPC, MSc Assistant Clinical Professor, Department of Anesthesia, St. Joseph s Healthcare Hamilton McMaster University

To understand the current options available to best manage pain after total knee arthroplasty and what is likely current best practice To understand what makes these options more attractive to us as practitioners To be aware of the strengths & limitations of this multi-centre trial

Total knee arthroplasty (TKA) is a common operation: 60k/yr in Canada, 700+k/yr in USA TKA associated with severe pain and 30% chronic pain incidence Pain also Limits and prolongs rehab results in poor outcomes is associated with an overall higher financial burden to patients and society

Current treatment involves opioids and (usually) a form of regional anesthesia Epidural Single shot or continuous Femoral nerve block (sfnb cfnb) Adductor canal block, sciatic block Local infiltration (LIA) Benefit of sfnb/cfnb over epidural or opioid alone is well established Someone even did a meta-analysis of 23 studies to prove that!

FNB is not perfect sfnb has a relatively short duration Both sfnb and cfnb are associated with motor block and proprioceptive block This increases the incidence of falling LIA is a simple alternative Multiple injections at the surgical site No risk of motor/proprioceptive block

cfnb has emerged as the gold standard for analgesia after TKA Offers a prolonged duration of analgesia Allows for titration to effect (pain control) and side-effect (weakness) The use of cfnb requires additional training and skills not ubiquitous amongst anesthesiologists This study aimed to compare cfnb to the simpler techniques of sfnb and LIA

Subjects from Sunnybrook and St. Joseph s Hamilton 18-65yo ASA I-III able to walk independently Primary TKA (not re-do) Not allergic to study drugs Language barrier major tranquilizers BMI >40 >30mg/day morphine equivalents

Randomized to 3 groups Group 1 cfnb Group 2 sfnb Group 3 LIA cfnb cfnb cfnb sfnb sfnb sfnb LIA LIA LIA RED denotes intervention BLACK denotes placebo (sham)

Interventions sfnb: ropivicaine 0.5% 20ml (sham LIA and infusion) cfnb: sfnb plus ropivicaine 0.2% 5ml/hr until POD2 0600 (sham LIA) LIA: ropivicaine 0.2% with epi 10mcg/ml x 150ml and ketorolac 30mg (sham s/cfnb)

Standard Care Midazolam & propofol sedation Bupivicaine and fentanyl spinal (no epimorph) PCA hydromorphone plus acetaminophen celecoxib hydromorph CR 3mg TID gabapentin 200mg TID Catheter bolus of ropivicaine 0.5% 10ml for pain >7/10

Outcomes Dynamic and static pain scores at multiple intervals Neuropathic pain 48h postop opioid consumption Requirement for rescue LA boluses Functional ability measures at multiple intervals Complications of interventions

spain dpain npain Opioids Rescue ROM TUG Functio n POD1 X X X X POD2 X X X X X 1.5mth X X 4.5mth X X X X X Injury

1031 approached 168 provided consent 120 randomized

cfnb N=40 sfnb N=39 LIA N=41 Age (y) 64.0 (7.4) 65.2 (9.2) 65.9 (8.0) Gender M:F 18 {44}:23 {56} 20 {51}: 19 {49} 20 {49}: 21 {51} BMI (kg m -2 ) 30.1 (3.5) 31.4 (4.7) 29.3 (4.8) ASA I/II/III 4/19/18 3/21/17 1/18/20 Pre-operative NRS 6.0 (2.2) 5.9 (2.8) 6.0 (2.7) Pre-operative 6-MWT 385 (116) 365 (137) 372 (116) (m) Pre-operative TUG (s) 10.8 (3.1) 11.8 (3.9) 13.2 (6.0) Pre-operative Knee Flexion (degrees) 115 (19) 110 (15) 112 (17) Pre-operative WOMAC 41 (13.9) 43.0 (18.9) 46 (20.4)

10 9 8 7 N=40 N=39 N=41 4.6 [3.3,6.0] 4.6 [3.3,6.0] 3.4 [2.1,4.7] 6 5 4 3 2 1 0 cfnb sfnb LIA ANOVA p = 0.05 Mean Difference NRS (95%CI) P-value (Tukey correction) cfnb LIA 1.2 [-0.1,2.5] 0.07 sfnb LIA 1.2 [-2.5,0.2] 0.10 cfnb sfnb 0.0 [-1.3,1.4] 1.00

140 76.1 (40.5) 93.7 (45.2) 77.2(40.8) 120 100 80 60 40 20 0 cfnb sfnb LIA N=40 N=39 N=41 ANOVA p = 0.12

Immediate postop cfnb sfnb LIA P-value N=40 N=39 N=41 dpain POD 1 4.8 [3.9,5.6] 6.4 [5.6,7.3] 4.4 [3.6,5.2] ANOVA: 0.00 Pairwise comparisons cfnb LIA: 0.35 [-1.0,1.7] Tukey: 0.82 cfnb sfnb: -1.7 [-3.1,-0.3] Tukey: 0.01 LIA sfnb: -2 [-3.4, -0.6] Tukey: <0.01 spain POD 1 2.7 [2.0,3.4] 3.9 [3.2,4.6] 2.5 [1.8,3.2] ANOVA: 0.01 Pairwise comparisons cfnb LIA: 0.3 [-1.0,1.4] Tukey: 0.86 cfnb sfnb: -1.2 [-2.7, 0] Tukey: 0.06 LIA sfnb: -2 [-2.6, -0.2] Tukey: 0.02 Worst pain POD 1 4.1 (2.8-5.4) 6.3 (5-7.5) 4.7 (3.7-5.9) ANOVA: 0.00 Pairwise cfnb LIA: -0.6 [-1.8, 0.7] Tukey: 0.53 comparisons cfnb sfnb: -2.7 [-3.5,-0.9] Tukey: 0.00 LIA sfnb: -1.6 [-2.9,-0.3] Tukey: 0.01 Bolus of catheter (n) 3 {8} 5 {13} 2 {5} 0.38 4.5 mo follow-up cfnb sfnb LIA N=37 N=33 N=38 pain at 4.5 mo 2.4 (2.5) 2.1(2) 1.9 (2.2) ANOVA 0.65 Chronic pain 4.5 mo 6.0 (6.63) 6.3 (7.1) 4.2 (5.9) ANOVA 0.32

No falls, infection or nerve damage reported Motor block (by blinded PT) 5-7% in all groups POD1 and nil POD2

cfnb and LIA are superior to sfnb for early analgesic outcomes (pain on POD 1) after TKA cfnb and LIA are both appropriate analgesic options for TKA depending on the experience of practitioners

FNB provides only anterolateral (~80%) converage (no sciatic) Opioid and neuroleptic regimen excessive Operator experience was sub-optimal at the SJH site Only epidural catheters placed regularly leading to higher risk of cfnb failure

Options are available for centres building their block program sfnb combined with posterior compartment LIA cfnb combined with posterior compartment LIA Opportunity for home catheter program (chronic pain still 10-15% in this study) Rescue LIA for failed FNB (need to develop sensitive and simple tests) Strength discrepancy pre/post spinal, sensory deficit pre spinal