Abstract
Introduction
Prosthetic designs that use porous metals possess an extremely high surface area and through capillary effect may potentially ‘absorb’ and later elute analgesic solution, serving as a surgical site drug depot. This study aimed to determine if a highly porous acetabular component submerged in an aqueous-based analgesic solution prior to implantation reduced postoperative pain scores and opioid consumption in the early post-operative period.
Methods
Using our IRB approved database, 200 consecutive opioid naïve primary THA patients operated on by a single surgeon at two institutions using the same acetabular component were identified. 100 patients had a standard volume/concentration of an analgesic cocktail soft-tissue injection at closure (control). 100 patients had their acetabular components submerged into the same cocktail prior to implantation (treatment) and the balance of the volume injected. Postoperative protocols were otherwise identical. Groups were compared for visual analog pain scores (VAS), opioid consumption, 1-year radiographic findings and surgical revision rates.
Results
VAS were lower in the treatment group at 6hrs (2.35±1.8 v. 3.31±2.3, p<0.01), 12hrs (2.00±1.6 v. 3.61±2.3, p<0.01), 18hrs (2.36±1.7 v. 3.44±1.9, p<0.01), and 24 hrs (2.20±1.6 v. 3.82±1.9, p<0.01). Opioid consumption was lower in the treatment group at all time point in the first 24 hours and significantly lower in the first 6 hours (7.18±9.42 MME v. 10.76±11.37 MME, p<0.05) and between 12 and 24 hours postoperatively (10.43±15.94 MME v. 17.08±22.75 MME, p<0.05). The total MME administered to the treatment group was significantly lower than the control group (48.3±59.7 MME vs. 76.1±78.6 MME, respectively; p<0.01). At one-year, there was no radiographic evidence of periacetabular lucencies and no revisions for loosening.
Conclusion
The use of a highly porous component commonly used in THA as a potential analgesic drug depot in combination with soft-tissue injections may reduce postoperative pain scores and opioid consumption compared to soft-tissue injections alone.
