Factors Associated with Adverse Events in Inpatient Elective Spine, Knee, and Hip Orthopaedic Surgery

Background: Orthopaedic procedures for degenerative musculoskeletal conditions (predominantly osteoarthritis and spinal stenosis) represent an increasing burden on the health-care system. These procedures are also associated with adverse event rates and related cost. The objective of this study was to identify risk factors for adverse events associated with orthopaedic surgeries as captured within a common clinical point-of-care system for documenting adverse events (Orthopaedic Surgical AdVerse Events Severity [OrthoSAVES] system). Methods: In-hospital adverse events were recorded at the point of care over a 2-year period for inpatient elective knee, hip, and spine orthopaedic procedures for degenerative musculoskeletal conditions. Multivariable logistic regression was employed to investigate the association between various factors (age, sex, surgical site, body mass index, surgical risk classification, operative duration, length of stay, and medical comorbidities) and the occurrence of adverse events. Results: The sample included 2,146 patients. The overall adverse event rate was 27% (571 of 2,146), and by surgical site, the rates were 29% (130 of 442) for spine; 27% (266 of 998) for knee; and 25% (175 of 706) for hip. The most common adverse events had a low severity grade, but spinal procedures demonstrated more adverse events with a severity grade of >= 3. Increasing age (odds ratio [OR] = 1.21, 95% confidence interval [CI] = 1.05 to 1.41, per 15-year interval), male sex (OR = 1.43, 95% CI = 1.16 to 1.77), increasing operative duration (OR = 1.13, 95% CI = 1.03 to 1.23, per 30-minute increase), length of stay (OR = 1.13, 95% CI = 1.10 to 1.17, per day), and undergoing revision surgery (OR = 2.23, 95% CI = 1.35 to 3.70) were independently associated with a greater likelihood of the occurrence of an adverse event. Spine surgery demonstrated decreased odds of an adverse event compared with knee surgery (OR = 0.38, 95% CI = 0.23 to 0.61) when operative duration and length of stay were taken into account. Conclusions: On the basis of our adjusted analysis, we found increasing age, male sex, revision surgery, length of stay, and increasing operative duration to be common independent risk factors for an adverse event across the population studied. The first 3 risk factors are not modifiable. The association between increasing operative duration and the risk of an adverse event across all anatomical regions and surgical procedures is a unique finding. However, modification of procedural efficiency is multifactorial and warrants further investigation.