Which inflammatory markers should we assess following Knee replacement? : A comparative study of unilateral and bilateral robotic TKR.

Abstract The presence of inflammatory markers may be a valuable indicator of postoperative healing and unforeseen complications following knee replacement surgery. They may also be a surrogate marker to compare and evaluate the impact of a particular surgical techniques and use of technology for performing a surgical procedure. The present study examined five common inflammatory markers [IL-6, CRP, LDH, AST and ESR] in patients who underwent robotic knee replacement surgery using surgeon controlled hand held CORI robotic system. Baseline venous blood samples were collected 12 hours before and after surgery and every 24 hours postop until discharge. A total of 48 participants were included in the study. Study participants were divided into two groups. In group I, 13 patients underwent bilateral total knee replacements (TKR); in group II, 35 underwent unilateral TKR. IL-6 increased significantly by 229.69 pg/ml at 12hrs in the bilateral group, and 115.51 post 24hr in the unilateral group (average IL-6 value <5 pg/ml). Peak CRP levels were observed 60 hours postop in the bilateral group at 34.87 and 16.71 in the unilateral group (standard CRP value < 0.6 mg/dL). It was found that ESR levels differed significantly both preoperatively and postoperatively (standard ESR value 15 to 20mm hour). Peak ESR levels were observed at 60hrs in both groups, 89mm/hr in the bilateral group and 46 mm/hr in the unilateral group. Peak LDH levels were observed 48 hours postop in both groups, 245.67 U/L in the bilateral and 244.15 U/L in the unilateral group (standard LDH value 140 to 280 U/L). AST level peak was observed at 48 hrs, 32.74 U/L in bilateral and 32 U/L in unilateral group (standard AST value 8 to 33 U/L). This is the first study to comprehensively evaluate and compare five expected inflammatory marker levels in patients who underwent robotic-assisted bilateral and unilateral TKR. This study found that IL-6 and CRP levels were statistically significantly higher in the bilateral knee replacement group than in the unilateral knee replacement group and may be the most relevant markers to monitor in the postoperative period.