Abstract
STUDY PURPOSES
To evaluate the role of “top up” intra-articular local anaesthetic injection in patients who have had UKR.
METHOD AND RESULTS
43 patients scheduled to have a cemented Oxford UKR were prospectively recruited and randomised. All patients had the same initial anaesthetic regime of general anaesthesia, femoral nerve block and intra-operative intra-articular infiltration. All patients had a multi-holed epidural catheter placed intra-articularly prior to wound closure. Patients had the same operative technique, post operative rehabilitation and rescue analgesia.
An independent, blinded observer recorded post-operative pain scores using a visual analogue score every 6 hours and any rescue analgesia. On the morning after surgery, 22 patients, (Group I), received 20 mls of 0.5% bupivicaine through the catheter whilst 21, (Group II), patients had 20 mls of normal saline by the same observer, after which the catheter was removed.
No statistical difference was found in pain scores on the day of operation between the groups. However, patients in Group I had a significantly better pain score initially post top up and at 6 hours (2.4 (0-8) vs 5.7 (2-9), p<0.001). This cohort of patients required less rescue analgesia (p<0.001). In addition, Group I had statistically significant higher patient satisfaction outcome scores after the infiltration, (p<0.001).
CONCLUSION
Our study has shown that injection of local anaesthesia via an intra-articular catheter does reduce pain scores when compared to placebo. This implies that this technique may have a role in providing optimal pain relief after UKR.
