Periarticular injections with continuous perfusion of local anaesthetics provide better pain relief and better function compared to femoral and sciatic blocks after TKA: a randomized clinical trial

Abstract

Purpose: Combined femoral and sciatic nerve blocks for post-operative pain management following total knee arthroplasty (TKA) improve patient satisfaction, decrease narcotic consumption and improve pain. However, accompanying motoric weakness can cause falls and related complications. We wonder whether peri-capsular injections in combination with intra-articular perfusion of local anaesthetics would result in equal or less pain without the related complications of nerve blocks. The objective of the study was to verify these aspects in a prospective randomized trial comparing both treatments.

Methods: Fifty TKA patients randomly received either a femoral (continuous) and a sciatic (single-shot) nerve block (CFNB group, 25 knees) or periarticular infiltrations and a continuous post-operative intra-articular infusion (PIAC group, 25 knees). VAS for pain, pain medication consumption, functional assessment, straight leg raising as well as KSS were recorded post-operatively for 6 days.

Results: VAS (p < 0.001) and KSS (p = 0.05) were significantly better for PIAC. There was increased pain following CFNB compared to PIAC. Catheters stayed for 4 days, a pain 'rebound' occurred after removing in CFNB but not after PIAC. There was no difference in regard to knee function (n.s.), but straight leg raising was significant better following PIAC. There were two falls in patients with CFNB.

Conclusion: Peri-capsular injections combined with an intra-articular catheter provide better pain control, no rebound pain with better function and might decrease the risk of complications related to motor weakness.

Level of evidence: I.

Keywords: Infiltration; Intra-articular; LIA; Nerve block; Peri-articular; TKA.