Background and Aims Innervation of the knee is intricate, originating from branches of the sciatic nerve, femoral and obturator nerves. Achieving effective post-operative analgesia whilst ensuring motor sparring is crucial in facilitating early mobilisation and optimising patient outcomes. Here we describe our current clinical approach for patients undergoing knee arthroplasty and the outcomes of these patients.

Methods All patients received spinal anaesthesia followed by blocks of the: distal femoral triangle, nerve of vastus intermedius (NVI), interspace between the popliteal artery and capsule of the knee (iPACK), and four genicular nerves. All blocks described here were performed or supervised by the same anaesthetic consultant. We worked closely with the orthopaedic surgical and physiotherapy teams to ensure a smooth day case pathway, emphasising the importance of early mobilisation. We collected data for consecutive patients undergoing this approach to knee arthroplasty during an 8 month period.

Results There were 50 patients in total. 39 total knee replacements (TKR), 8 unicompartmental knee replacements (UKR) and 3 revision TKR. Eight patients (4 TKR, 4 UKR) were discharged on the day of surgery. All patients mobilised within 24 hours. The mean time to requiring post-operative morphine was 17 hours. All 7 blocks could be performed in less than 10 minutes by an anaesthetic trainee.

Conclusions Our experience highlights the feasibility and potential advantages of employing a precise and targeted regional anaesthetic strategy for knee arthroplasty. Our findings demonstrate that this anaesthetic modality offers excellent pain relief while preserving motor function, thus enabling the provision of knee arthroplasty as day case operation.

Ethical Approval-2