Postoperative Pain and Opiate Requirement is Increased Following Second-Side Surgery Among Patients Undergoing Staged Total Knee Arthroplasty

Background Primary total knee arthroplasty (TKA) continues to grow exponentially, with a significant subset of patients requiring staged bilateral procedures. The optimal interval between staged procedures and effective strategies to minimize postoperative pain to enhance rehabilitation and mobility remain poorly understood. Methods 160 consecutive patients undergoing staged bilateral TKA between August 2017 and January-2021 was retrospectively reviewed. Patients with a history of chronic opioid dependency were excluded. Baseline demographics, primary outcome measures, including visual analog scale (VAS) pain scores, perioperative opioid utilization (MME/day), and surgical satisfaction were evaluated. All patients had a minimum follow-up of 1-year-postoperatively. All univariate and multivariate statistical analyses were performed with significance given by P < .05. Results The mean interval between staged TKA was 8-weeks (standard deviation, 4.9-weeks). Preoperative VAS pain scores were significantly higher for the initial TKA, confirming that the more symptomatic knee was addressed first. Despite this, VAS pain scores were significantly increased following second-side TKA at 6-months postoperatively ( P = .001). Multivariate analysis identified weekly interval duration between staged procedures as the single-most predictive factor of increased pain following second-side TKA (β = −0.106; P < .01). Female patients were increasingly susceptible to elevated pain levels following second-side TKA (β = 0.372; P = .057). Conclusions Postoperative pain increases after second-side TKA in staged-bilateral procedures, despite the more symptomatic side being addressed first. Our study identified weekly interval between staged procedures as the single-most predictive factor of pain, and female patients being predisposed to heightened pain following second-side TKA; implicating nociceptive pathways require weeks to normalize, necessitating gender-specific pain management and extended intervals.