Patients with Inflammatory Bowel Disease Do Not Have An Increased Risk of Infection or All-Cause Revision Following TKA

Author

Kingery MT

Published

May 29, 2023

Explore data

Methods

Summary of included patients

Initial data query yielded a total of 409,806 cases in 320,582 patients. Revision cases where the corresponding primary case was not found in the database (e.g., because the primary occurred prior to the study period or outside of New York state) were excluded (10,427 cases in 7,744 patients). Additional cases with illogical or inconsistent data, likely to be the result of medical coding errors, were removed as necessary (e.g., patients greater than 2 primary cases or more than 1 primary case of the same laterality). A final cohort of 382,166 primary cases in 314,621 patients were included in the analysis. Among patients in the final cohort, a total of 216,030 primary cases in 182,295 patients had a minimum of 2 years postoperative follow-up.

Results

Demographics

Table 1: Patient demographics for all patients who underwent primary TKA during the study period.
Characteristic IBD p-value2
IBD, N = 2,3931 No IBD, N = 379,7731
Indication <0.001
    Osteoarthritis 2,189 (91.5%) 357,726 (94.2%)
    Inflammatory Arthritis 127 (5.3%) 12,408 (3.3%)
    Other or Unspecified 77 (3.2%) 9,639 (2.5%)
Age (years) 66.1 +/- 9.6 66.2 +/- 9.9 0.458
Sex 0.006
    Female 1,591 (66.5%) 242,285 (63.8%)
    Male 802 (33.5%) 137,483 (36.2%)
Race <0.001
    White 2,061 (86.1%) 278,356 (73.3%)
    Black 112 (4.7%) 36,635 (9.6%)
    Hispanic 102 (4.3%) 29,859 (7.9%)
    Asian 19 (0.8%) 8,398 (2.2%)
    Native American 4 (0.2%) 1,159 (0.3%)
    Other or Unknown 95 (4.0%) 25,366 (6.7%)
Elixhauser score 0.9 +/- 4.9 0.4 +/- 4.3 <0.001
Insurance <0.001
    Private 1,018 (42.5%) 166,754 (43.9%)
    Medicare 1,235 (51.6%) 181,383 (47.8%)
    Medicaid 42 (1.8%) 11,726 (3.1%)
    Worker's Compensation 76 (3.2%) 15,813 (4.2%)
    Other 22 (0.9%) 4,097 (1.1%)
Follow-up duration (years) 3.4 +/- 2.9 3.3 +/- 3.0 0.057
1 n (%); Mean +/- SD
2 Pearson’s Chi-squared test; Welch Two Sample t-test
Table 2: Patient demographics for patients who underwent TKA with at least 2 years of postoperative follow-up.
Characteristic IBD p-value2
IBD, N = 1,4281 No IBD, N = 214,6021
Indication <0.001
    Osteoarthritis 1,293 (90.5%) 200,887 (93.6%)
    Inflammatory Arthritis 83 (5.8%) 7,448 (3.5%)
    Other or Unspecified 52 (3.6%) 6,267 (2.9%)
Age (years) 65.9 +/- 9.7 66.2 +/- 10.0 0.261
Sex 0.003
    Female 979 (68.6%) 139,108 (64.8%)
    Male 449 (31.4%) 75,494 (35.2%)
Race <0.001
    White 1,220 (85.4%) 161,756 (75.4%)
    Black 78 (5.5%) 19,908 (9.3%)
    Hispanic 57 (4.0%) 16,159 (7.5%)
    Asian 10 (0.7%) 2,800 (1.3%)
    Native American 2 (0.1%) 664 (0.3%)
    Other or Unknown 61 (4.3%) 13,315 (6.2%)
Elixhauser score 0.9 +/- 4.8 0.6 +/- 4.3 0.006
Insurance 0.003
    Private 613 (42.9%) 93,623 (43.6%)
    Medicare 738 (51.7%) 103,828 (48.4%)
    Medicaid 21 (1.5%) 5,653 (2.6%)
    Worker's Compensation 45 (3.2%) 9,336 (4.4%)
    Other 11 (0.8%) 2,162 (1.0%)
Follow-up duration (years) 5.3 +/- 2.3 5.5 +/- 2.3 0.058
1 n (%); Mean +/- SD
2 Pearson’s Chi-squared test; Welch Two Sample t-test; Fisher’s Exact Test for Count Data with simulated p-value (based on 2000 replicates)

Outcomes

Table 3: Outcomes following TKA for cases with ≥ 2 years postoperative follow-up.
Characteristic IBD p-value2
IBD, N = 1,4281 No IBD, N = 214,6021
Length of hospital stay (days) 3.6 +/- 2.6 3.3 +/- 1.8 0.003
Discharge disposition 0.598
    Home 741 (51.9%) 112,338 (52.3%)
    Skilled Nursing Facility 456 (31.9%) 70,230 (32.7%)
    Inpatient Rehabilitation 226 (15.8%) 30,654 (14.3%)
    Transfer 5 (0.4%) 1,225 (0.6%)
    Against Medical Advice 0 (0.0%) 62 (0.0%)
    Discharged to Court 0 (0.0%) 71 (0.0%)
    Hospice 0 (0.0%) 20 (0.0%)
    Expired 0 (0.0%) 0 (0.0%)
    Unknown 0 (0.0%) 2 (0.0%)
ED presentation within 3 months 176 (12.3%) 23,986 (11.2%) 0.170
Readmission within 3 months 137 (9.6%) 16,644 (7.8%) 0.010
Readmission within 12 months 240 (16.8%) 27,261 (12.7%) <0.001
All-cause revision 69 (4.8%) 10,041 (4.7%) 0.785
Revision for PJI 24 (1.7%) 3,120 (1.5%) 0.476
Time to first revision (years) 2.2 +/- 2.1 2.4 +/- 2.1 0.176
Reoperation within 3 months of primary 12 (0.8%) 1,130 (0.5%) 0.103
Reoperation within 12 months of primary 30 (2.1%) 3,222 (1.5%) 0.064
1 Mean +/- SD; n (%)
2 Wilcoxon rank sum test; Fisher’s Exact Test for Count Data with simulated p-value (based on 2000 replicates); Pearson’s Chi-squared test
Table 4: Perioperative outcomes following THA for all patients
Characteristic IBD p-value2
IBD, N = 2,3931 No IBD, N = 379,7731
ED presentation within 3 months 256 (10.7%) 36,496 (9.6%) 0.072
Readmission within 3 months 196 (8.2%) 24,041 (6.3%) <0.001
Readmission within 12 months 330 (13.8%) 39,414 (10.4%) <0.001
Mortality within 3 months 10 (0.4%) 542 (0.1%) 0.003
Mortality within 12 months 12 (0.5%) 1,307 (0.3%) 0.191
1 n (%)
2 Pearson’s Chi-squared test; Fisher’s exact test

Survival analysis

Kaplan-Meier plots

Figure 1: KM curves

Figure: Kaplan-Meier plots demonstrating survival probability over time between groups. There is no evidence for any difference between patients with IBD and patients without IBD in terms of (A) PJI-free survival (0.221) or (B) all-cause revision-free survival following TKA (0.938). Note: y-axis is limited to 90-100% survival to visualize detail of curves.

Cox proportional hazards

Table 5: Cox PH
Characteristic Time to PJI Time to All-Cause Revision
HR1 95% CI1 p-value HR1 95% CI1 p-value
IBD
    No IBD — — — —
    IBD 1.23 0.87, 1.73 0.236 0.98 0.79, 1.23 0.890
Age (years) 0.98 0.98, 0.98 <0.001 0.96 0.96, 0.96 <0.001
Sex
    Female — — — —
    Male 1.90 1.79, 2.02 <0.001 1.24 1.19, 1.28 <0.001
Elixhauser score 1.04 1.04, 1.05 <0.001 1.02 1.02, 1.03 <0.001
Operative indication
    Other or Unspecified — — — —
    Osteoarthritis 0.79 0.67, 0.93 0.005 0.99 0.89, 1.10 0.822
    Inflammatory Arthritis 1.19 0.96, 1.48 0.108 1.02 0.89, 1.17 0.774
Obesity
    No — — — —
    Yes 1.43 1.33, 1.53 <0.001 1.09 1.05, 1.13 <0.001
DM
    No — — — —
    Yes 1.09 1.01, 1.18 0.022 0.97 0.93, 1.02 0.208
History of smoking
    No — — — —
    Yes 1.41 1.27, 1.56 <0.001 1.18 1.11, 1.25 <0.001
1 HR = Hazard Ratio, CI = Confidence Interval

Table: Cox proportional hazards models evaluating the effect of IBD time to PJI (left) and time to all-cause revision (right). When controlling for the covariates listed, IBD has no significant effect on the outcomes of interest.

GLM for risk of revision

Table 6: GLMs
Characteristic Odds of PJI Odds of All-Cause Revision
OR1 95% CI1 p-value OR1 95% CI1 p-value
IBD
    No IBD — — — —
    IBD 1.13 0.73, 1.65 0.568 1.01 0.79, 1.28 0.923
Age (years) 0.97 0.97, 0.98 <0.001 0.95 0.95, 0.96 <0.001
Sex
    Female — — — —
    Male 1.88 1.75, 2.02 <0.001 1.20 1.16, 1.26 <0.001
Elixhauser score 1.03 1.02, 1.04 <0.001 1.01 1.01, 1.02 <0.001
Operative indication
    Other or Unspecified — — — —
    Osteoarthritis 0.86 0.71, 1.04 0.116 1.10 0.97, 1.24 0.129
    Inflammatory Arthritis 1.20 0.94, 1.55 0.150 1.06 0.90, 1.25 0.471
Obesity
    No — — — —
    Yes 1.28 1.18, 1.39 <0.001 0.96 0.92, 1.01 0.122
DM
    No — — — —
    Yes 1.14 1.04, 1.24 0.003 0.99 0.94, 1.05 0.817
Length of hospital stay (days) 1.06 1.05, 1.07 <0.001 1.05 1.04, 1.06 <0.001
1 OR = Odds Ratio, CI = Confidence Interval

Table. Logistic regression models demonstrating the odds of revision for PJI (left) and odds of all-cause revision (right) for patients undergoing TKA with at least 2 years of follow-up. Patients with IBD did not have an increased risk of infection-related revision or all-cause revision compared to patients without IBD.