Predicting Short Term Morbidity following Revision Hip and Knee Arthroplasty A Review of ACS-NSQIP 2006-2012 Arjun Sebastian, M.D., Stephanie Polites, M.D., Kristine Thomsen, B.S., Elizabeth Habermann, Ph.D., Mark Pagnano, M.D. ACS NSQIP National Conference July 27, 2014
Background The incidence of primary total knee and hip arthroplasty rising. The demand for revision arthroplasty will continue to rise. Given the increased utilization, outcomes and quality need to be better defined following revision arthroplasty. Kurtz S M et al. J Bone Joint Surg Am 2014;96:624-630
- Complication rate: 4.9% - Mortality rate: 0.35% - Complication rate: 5.6% - Mortality rate: 0.18% - Readmission rate: 4.2% (THA) and 4.6% (TKA)
Methods ACS-NSQIP PUF used to identify patients who underwent: Revision knee (4209) and revision hip (4133) arthroplasty. 30 day postoperative events: Mortality Major/minor systemic and local complications 30 day unplanned readmissions (2011-2012) Univariate testing Multivariable logistic regression analysis.
Results Patient Demographics and Comorbidities Revision Knee Revision Hip ASA 3 Chronic Steroid Use PVD Hypertension CHF COPD Diabetes Smoking BMI 35 Male Age > 70 0 10 20 30 40 50 60 70 80 %
Revision TKA (n=4209) Characteristic Number (%) Mortality 17 (0.4%) Major systemic complications 237 (5.6%) Pulmonary embolus 14 (0.3%) Sepsis 51 (1.2%) Stroke 6 (0.1%) Acute renal failure 7 (0.2%) Myocardial Infarction 10 (0.2%) Return to OR 160 (3.8%) Minor systemic complications 125 (3.0%) Urinary tract infection 58 (1.4%) DVT 37 (0.9%) Pneumonia 21 (0.5%) Renal insufficiency 14 (0.3%) Major local complications 77 (1.8%) Deep SSI* 72 (1.7%) Peripheral nerve injury 5 (0.1%) Minor local complications 55 (1.3%) Superficial SSI 36 (0.9%) Wound disruption 20 (0.5%) Unplanned readmission 176 (7.0%) Overall complication rate: 9.3% Revision THA (n=4133) Characteristic Number (%) Mortality 42 (1.0%) Major systemic complications 359 (8.7%) Pulmonary embolus 11 (0.3%) Sepsis 59 (1.4%) Stroke 11 (0.3%) Acute renal failure 9 (0.2%) Myocardial infarction 23 (0.6%) Return to OR 264 (6.4%) Minor systemic complications 141 (3.4%) Urinary tract infection 81 (2.0%) DVT 27 (0.7%) Pneumonia 30 (0.7%) Renal insufficiency 11 (0.3%) Major local complications 131 (3.2%) Deep SSI* 60 (1.5%) Peripheral nerve injury 11 (0.3%) Minor local complications 68 (1.6%) Superficial SSI 54 (1.3%) Wound disruption 15 (0.4%) Unplanned Readmission 227 (7.8%) Overall complication rate: 12.7%
Independent Risk Factors Revision TKA Characteristic Odds P value Ratio Major Systemic Complications Recent weight loss 3.43.014 ASA 3 1.77.001 Bleeding Disorders 1.77.014 African American race 1.66.014 Male gender 1.54.004 Length of Stay (per 3d increase) 1.56 <.001 Minor Systemic Complications CHF 4.66.006 BUN > 40 3.05.016 Albumin 3 2.09.037 WBC > 12 2.29.008 Length of Stay (per 3d increase) 1.28 <.001 Major Local Complications Recent weight loss 5.99.006 Length of Stay (per 3d increase) 1.19.003 Minor Local Complications BMI > 40 vs BMI < 25 3.81.037 COPD 2.61.021 Length of Stay (per 3d increase) 1.18.018 Unplanned Readmission (2011-2012) Male Gender 1.70.002 African American race 1.96.004 BMI > 40 vs BMI < 25 1.93.047 Recent weight loss 5.40.008 Na < 130 4.50.010 WBC > 12 2.35.003 ASA 3 1.66.009
Independent Risk Factors Revision THA Characteristic Odds Ratio P value Major Systemic Complications BMI > 40 vs BMI 25 30 1.92.002 Smoker 1.47.015 Hematocrit < 33 1.35.050 Functional Dependence 1.61.002 Length of stay (per 3d increase) 1.35 <.001 Transfusion 1.64 <.001 Minor Systemic Complications Age > 70 2.00 <.001 Hematocrit < 33 1.75.011 Length of stay (per 3d increase) 1.20 <.001 Major Local Complications Hematocrit < 33 1.61.044 Functional Dependence 1.75.019 Length of stay (per 3d increase) 1.19 <.001 Minor Local Complications BMI > 40 vs BMI 25-30 4.97 <.001 Length of stay (per 3d increase) 1.18 <.001 Unplanned Readmission (2011-2012) BMI >40 vs BMI 25-30 1.82.016 WBC 12 1.88.026 Hematocrit < 33 1.52.028
Discussion Incidence of Complications 1.7-2.6x higher Unplanned Readmissions 1.5-1.9x higher. Similar age and comorbid disease burden TKA: Belmont et al -> Age 67.3, 61.2% obese (BMI > 30), 18.2% diabetic, 50% ASA 3. Our study-> Age 65.9, 60.3% obese, 20.8% diabetic, 57.2% ASA 3. THA: Belmont et al -> Age 67.3, 42% obese, 11% diabetic, ASA 3 43.2%. Our study-> Age 66.3, 39.8% obese, 12.5% diabetic, 55.4% ASA 3.
Discussion Potential explanations Longer operative times Revision TKA (134 min) vs 97 min in 1 TKA Revision THA (147 min) vs 98 min in 1 THA Longer length of hospitalization Revision THA (4.4 d) Revision TKA (3.8 d) Functional dependence 11% in revision THA 6.3% in revision TKA Return to the OR (Revision TKA 3.8%, THA 6.4%)
Discussion Revision THA- key predictors Anemia, obesity, functional dependence, and length of stay. Revision TKA- key predictors Recent weight loss, length of stay, and African American race. Highlights the importance of preoperative medical optimization. Patients undergoing revision THA/TKA should be risk stratified accordingly.
Conclusions Revision knee arthroplasty Overall complication incidence: 9.3% Unplanned readmission incidence: 7.0% Revision hip arthroplasty Overall complication rate: 12.7% Unplanned readmission rate: 7.8% Complications are 1.7-2.6 times higher Readmissions are 1.5-1.9 times higher Quality metrics must account for the increased incidence of complications and readmissions as well as associated risk factors.
Questions & Discussion