Abstract
Increased operative time has been previously identified as a risk factor for complications following total joint arthroplasty. The purpose of this study was to evaluate the influence of surgical time on 30-day complications following Total Knee Arthroplasty (TKA) and to determine if there were specific time intervals associated with worse outcomes.
The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was utilized to identify patients ≥18 years who underwent TKA between 2005 and 2016 using procedural codes. Patients with surgical durations >240 minutes were excluded. Patient demographics, operation length, and 30-day major and minor complication rates were captured. Multivariable logistic regression was used to determine if the rate of complications differed depending on length of operation, while adjusting for age, sex, American Society of Anaesthesiologists (ASA) class, functional status, smoking status, comorbidities, anesthesia type, and Body Mass Index (BMI). Multivariable linear regression was used to identify independent predictors of duration of surgery.
A total of 213,921 TKA patients (average age 67 ± 10 years) were identified from the database. Within 30-days of the index procedure, 3,321 (1.55%) experienced a major complication, and 6,144 (2.86%) experienced a minor complication. Mean surgical duration was 92 minutes (range 20 – 240). Underweight, or overweight/obese BMI, male sex, hypertension, cancer, dependent functional status, epidural anaesthesia, and ASA class III and IV were determined to be independent predictors of prolonged operation length, while COPD, current smoking, spinal anesthesia, and older age predicted lower operation times.
Operation lengths ≥ 90 minutes significantly increased the risk of both major and minor complications (P>0.01). Specifically, the rates of deep vein thrombosis (DVT), unplanned reintubation, surgical site infection (SSI), sepsis, and wound disruption were higher for patients whose operations lasted ≥ 90 minutes (p 0.05). With respect to specific complications, following covariate adjustment, operation lengths ≥ 90 minutes increased the risk of DVT, deep and superficial incisional SSI, and wound disruption, while operation lengths ≥ 120 minutes increased the risk of deep, non-incisional SSI, and sepsis (P < 0 .01).
Surgical times of ≥90 minutes independently increase the 30-day risk of DVT, infection, and wound disruption following TKA after controlling for other variables that influence operation length. This study confirms the importance of surgical duration on early outcomes following TKA.
