Background and aims Total knee replacement (TKR) is performed for end stage knee disease. Incidence of moderate to severe pain post-operatively has been reported as roughly 50%. This delays mobilisation, physiotherapy and recovery. Adductor canal block (ACB) is a relatively new block being increasingly used for pain control post-TKR. Potential advantage is that only the terminal sensory branch of the femoral is blocked — the saphenous nerve, thus avoiding the motor block (quadriceps weakness). Our aim was to ascertain the use of the block in our institute and potential advantage in terms of pain relief.
Methods Retrospective analysis of anaesthetic notes and prescription data. 50 cases. Period August 2017 to October 2017.
Results Age range: 49–89 years
M/F ratio: 20/30
Block/no block: 16/34
Volume of local: range 5–20 ml
Strength of local: 0.25%–0.75%
Time to first dose of morphine for patient with block: average time 9.13 hours
Time to first dose of morphine for patient without block: average time 3.64 hours
Conclusions Various studies and meta-analysis also show that adductor canal block is useful for analgesia for TKR enhancing pain relief and improving mobility. Comparable analgesia and no motor block with regards to femoral nerve block makes it further appealing in terms of enhanced recovery. Confounding factors include:
Volume of LA used for SAB
Volume of LA used for block
Strength of LA used for block
Small number of patients receiving the block