Evaluation of Effectiveness of Periarticular Injection of Cocktail of Drugs in Pain Management in Total Knee Arthoplasty

Background: Post-operative pain management is a major concern in TKA. Periarticular
infiltration in TKA is a technique in which a cocktail of drug combination is injected
into the periarticular soft tissues such as posterior capsule, medial and lateral collateral
ligaments, quadriceps mechanism, and peripatellar tissue at the end of the surgery.
Recent studies found that periarticular injection significantly improved pain relief from
24hr to 1wk and straight leg raise in the early postoperative period. Therefore in our
study, we evaluated a combination of local anaesthetic (Ropivacaine), alpha agonist
(clonidine), cox-2 inhibitor (ketorolac) as a multimodal analgesic to effect on various
pain receptors. We also added epinephrine to reduce their absorption and prolongation
of their effect (analgesics).Methods: This study was conducted on 80 patients who
were randomly divided into 2 groups, group’s 42 patients (received local infiltration
analgesia) and group c 38 patients (received normal salineinjection) based on softwarederived random numbersequence. The data was revealed to the investigators at the end
of the study. The statistical analysis of the data set was performed with KolmogorovSmirnov test (p < 0.05) for normality and an unpaired-t test was used to compare mean
of the group for the significance of differences of outcome variable. Dichotomous data
were analyzed using chi-square test or Fisher’s exact test, as appropriate. A p-value of<
0.05 was considered statistically significant. Results: We observed that the mean VAS
score in Group S was lower (2.57) as compared to the Group C (4.66). Patients in
group ‘S’ were more satisfied and felt less pain with increased range of motion
andphysiotherapy. The patients in group ‘S’ were discharged earlier as they had less
pain on physiotherapy as well as on rest and also there is increased mobility of knee
joint. Conclusion: Our study suggests that periarticular injection of cocktail of drugs is
a safe and effective multimodal analgesia technique that can be used for the
management of pain in patient of total knee arthoplasty.