Randomized prospective comparative study of adductor canal block versus periarticular infiltration on early functional outcome after unilateral total knee arthroplasty

Background: Total knee arthroplasty (TKA) is associated with significant post-operative pain. Effective pain relief is essential for early post-operative rehabilitation. Periarticular infiltration (PAI) and Adductor canal block (ACB) have become popular modes of pain management after TKA. Our aim is to compare their efficacy and impact on early functional outcome in patients undergoing TKA. Methods: A single-blind randomised controlled trial, 100 patients undergoing unilateral primary TKA for symptomatic OA were allocated to either of the two groups (50 in each arm). Postoperative ultrasound guided single shot of ACB (Group A) or intra operative PAI (Group B). All patients underwent TKA without patella resurfacing under spinal anaesthesia. Pre-operative work up, surgical technique, post-operative management were standardised for all the patients. Patients were assessed for pain using VAS (Visual analogue scale) at 6, 12, 24 hrs after surgery, haemoglobin level preoperatively and post operatively on day 1 to calculate blood loss, hospital stay, tourniquet time (TT), operative time (OT) and post-operative complications by an independent observer blinded to the group allocation. Results: Patients were matched for age, gender, ASA grade and Deformity. VAS (scale 0-10) between PAI & ACB at 6, 12 & 24 hours were significantly different (p<0.05) with higher score seen in the patients with ACB at all time points. TT and OT were significantly longer in the PAI than ACB. No significant difference in the hospital stay observed. No complications occurred during the study. Conclusion: PAI achieves better pain control as compared to ACB in patients undergoing unilateral TKA

Tourniquet induced ischemia and changes in metabolism during TKA: a randomized study using microdialysis

BACKGROUND: Tourniquet use in total knee arthroplasty (TKA) surgery is applied to minimize blood loss thereby creating better overview of the surgical field. This induces ischemia in the skeletal muscle resulting in reperfusion injury. Our aim was to investigate the in vivo metabolic changes in the skeletal muscle during TKA surgery using microdialysis (MD).METHODS: Seventy patients were randomly allocated to tourniquet group (n = 35) or non-tourniquet group (n = 35). Prior to surgery, catheters were inserted in the operated leg and non-operated leg. Interstitial dialysate was collected before and after surgery and at 20 min intervals during a 5 h reperfusion period. Main variables were ischemic metabolites: glucose, pyruvate, lactate and glycerol and L/P ratio.RESULTS: Significant difference in all metabolites was detected between the two groups, caused by tourniquet application. Tourniquet induced ischemia resulted in decreased levels of glucose and pyruvate to 54 and 60 % respectively, compared to baseline. Simultaneously, accumulation of lactate to 116 % and glycerol to 190 % was observed. L/P ratio was elevated indicating ischemia. In the non-tourniquet group the metabolite changes were less profound and normalized within 60 min.CONCLUSIONS: Microdialysis revealed that performing TKA with tourniquet is associated with increased ischemia. This affects all metabolites but the changes are normalized after 5 h.</p

The effect of tourniquet use on hidden blood loss in total knee arthroplasty

The objective of this study was to examine the characteristics of hidden blood loss and assess the effects of using a tourniquet on postoperative hidden loss in patients undergoing primary total knee arthroplasty. Eighty patients were randomised into two groups: one group underwent operation with a tourniquet and one without. Operating time, perioperative blood loss, hidden blood loss, free haemoglobin, swelling, ecchymosis, straight leg raising action and knee flexion were measured. There were significant differences in the hidden blood loss, free haemoglobin, postoperative swelling, extent of ecchymosis, straight leg raising and postoperative knee flexion in the early period after operation between the two groups. Our results indicate that knee arthroplasty operations with a tourniquet might promote postoperative hidden blood loss and hinder patients’ in early postoperative rehabilitation exercises