Cemented arthroplasty for femoral neck fractures
Methods
Summary of included patients
Initial data query yielded a total of 106,418 cases in 93,226 patients who underwent treatment for femoral neck fracture during the study period. Revision cases associated with prior treatment of femoral neck fracture 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 (22,224 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). Cases that underwent fracture fixation were excluded from this analysis (42,252 cases in 41,463 patients). This resulted in 50,064 femoral neck fracture cases in 48,651 patients that were treated with hemiarthroplasty or THA. The first half of the study period utilized ICD-9 codes which did not specify whether an arthroplasty was performed with cementation. Additionally, ICD-10 codes that do not specify the method of implant fixation are often used. A total of 33,525 cases in 32,772 patients did not include details of fixation method. Therefore, the final cohort consisted of 16,539 primary cases in 16,265 patients containing details related to implant fixation method.
Results
Demographics
| Characteristic | Implant Fixation | p-value2 | |
|---|---|---|---|
| Cemented, N = 8,6721 | Uncemented, N = 7,8671 | ||
| Surgery | <0.001 | ||
| Hemiarthroplasty | 7,563 (87.2%) | 5,594 (71.1%) | |
| THA | 1,109 (12.8%) | 2,273 (28.9%) | |
| Age (years) | 83.2 +/- 9.3 | 79.0 +/- 11.0 | <0.001 |
| Sex | <0.001 | ||
| Female | 6,281 (72.4%) | 5,123 (65.1%) | |
| Male | 2,391 (27.6%) | 2,744 (34.9%) | |
| Race | 0.650 | ||
| White | 7,216 (83.2%) | 6,521 (82.9%) | |
| Black | 383 (4.4%) | 341 (4.3%) | |
| Hispanic | 362 (4.2%) | 347 (4.4%) | |
| Asian | 212 (2.4%) | 180 (2.3%) | |
| Native American | 12 (0.1%) | 18 (0.2%) | |
| Other or Unknown | 487 (5.6%) | 460 (5.8%) | |
| Elixhauser score | 8.3 +/- 7.9 | 7.2 +/- 7.7 | <0.001 |
| Insurance | <0.001 | ||
| Private | 1,088 (12.5%) | 1,276 (16.2%) | |
| Medicare | 7,359 (84.9%) | 6,186 (78.6%) | |
| Medicaid | 142 (1.6%) | 199 (2.5%) | |
| Worker's Compensation | 27 (0.3%) | 87 (1.1%) | |
| Other | 56 (0.6%) | 119 (1.5%) | |
| Follow-up duration (years) | 0.9 +/- 1.2 | 1.0 +/- 1.2 | <0.001 |
| 1 n (%); Mean +/- SD | |||
| 2 Pearson's Chi-squared test; Welch Two Sample t-test | |||
| Characteristic | Implant Fixation | p-value2 | |
|---|---|---|---|
| Cemented, N = 7,5631 | Uncemented, N = 5,5941 | ||
| Age (years) | 83.9 +/- 9.0 | 81.9 +/- 9.7 | <0.001 |
| Sex | <0.001 | ||
| Female | 5,468 (72.3%) | 3,661 (65.4%) | |
| Male | 2,095 (27.7%) | 1,933 (34.6%) | |
| Race | 0.653 | ||
| White | 6,282 (83.1%) | 4,602 (82.3%) | |
| Black | 337 (4.5%) | 269 (4.8%) | |
| Hispanic | 318 (4.2%) | 241 (4.3%) | |
| Asian | 190 (2.5%) | 142 (2.5%) | |
| Native American | 9 (0.1%) | 12 (0.2%) | |
| Other or Unknown | 427 (5.6%) | 328 (5.9%) | |
| Elixhauser score | 8.5 +/- 7.9 | 8.2 +/- 7.9 | 0.017 |
| Insurance | <0.001 | ||
| Private | 927 (12.3%) | 680 (12.2%) | |
| Medicare | 6,453 (85.3%) | 4,689 (83.8%) | |
| Medicaid | 122 (1.6%) | 118 (2.1%) | |
| Worker's Compensation | 20 (0.3%) | 26 (0.5%) | |
| Other | 41 (0.5%) | 81 (1.4%) | |
| Follow-up duration (years) | 0.9 +/- 1.2 | 1.0 +/- 1.2 | 0.003 |
| 1 Mean +/- SD; n (%) | |||
| 2 Welch Two Sample t-test; Pearson's Chi-squared test | |||
| Characteristic | Implant Fixation | p-value2 | |
|---|---|---|---|
| Cemented, N = 1,1091 | Uncemented, N = 2,2731 | ||
| Age (years) | 78.5 +/- 10.4 | 71.9 +/- 10.8 | <0.001 |
| Sex | <0.001 | ||
| Female | 813 (73.3%) | 1,462 (64.3%) | |
| Male | 296 (26.7%) | 811 (35.7%) | |
| Race | 0.612 | ||
| White | 934 (84.2%) | 1,919 (84.4%) | |
| Black | 46 (4.1%) | 72 (3.2%) | |
| Hispanic | 44 (4.0%) | 106 (4.7%) | |
| Asian | 22 (2.0%) | 38 (1.7%) | |
| Native American | 3 (0.3%) | 6 (0.3%) | |
| Other or Unknown | 60 (5.4%) | 132 (5.8%) | |
| Elixhauser score | 6.6 +/- 7.5 | 4.7 +/- 6.7 | <0.001 |
| Insurance | <0.001 | ||
| Private | 161 (14.5%) | 596 (26.2%) | |
| Medicare | 906 (81.7%) | 1,497 (65.9%) | |
| Medicaid | 20 (1.8%) | 81 (3.6%) | |
| Worker's Compensation | 7 (0.6%) | 61 (2.7%) | |
| Other | 15 (1.4%) | 38 (1.7%) | |
| Follow-up duration (years) | 1.0 +/- 1.3 | 1.2 +/- 1.3 | 0.002 |
| 1 Mean +/- SD; n (%) | |||
| 2 Welch Two Sample t-test; Pearson's Chi-squared test; Fisher's Exact Test for Count Data with simulated p-value (based on 2000 replicates) | |||
Outcomes
Odds of undergoing cemented fixation
| Characteristic | Hemiarthroplasty | THA | ||||
|---|---|---|---|---|---|---|
| OR1 | 95% CI1 | p-value | OR1 | 95% CI1 | p-value | |
| Age (years) | 1.02 | 1.02, 1.03 | <0.001 | 1.05 | 1.05, 1.06 | <0.001 |
| Sex | ||||||
| Male | — | — | — | — | ||
| Female | 1.35 | 1.25, 1.45 | <0.001 | 1.52 | 1.28, 1.80 | <0.001 |
| Race | ||||||
| White | — | — | — | — | ||
| Black | 1.00 | 0.85, 1.18 | 0.994 | 1.46 | 0.97, 2.18 | 0.069 |
| Hispanic | 0.99 | 0.83, 1.18 | 0.895 | 0.94 | 0.64, 1.37 | 0.761 |
| Asian | 1.03 | 0.82, 1.29 | 0.823 | 1.55 | 0.86, 2.72 | 0.133 |
| Native American | 0.58 | 0.23, 1.38 | 0.220 | 1.39 | 0.28, 5.62 | 0.655 |
| Other or Unknown | 0.97 | 0.83, 1.12 | 0.657 | 1.07 | 0.77, 1.49 | 0.681 |
| Insurance | ||||||
| Medicare | — | — | — | — | ||
| Private | 1.10 | 0.98, 1.22 | 0.095 | 0.80 | 0.64, 0.99 | 0.038 |
| Medicaid | 1.05 | 0.80, 1.37 | 0.745 | 0.99 | 0.57, 1.67 | 0.978 |
| Worker's Compensation | 0.72 | 0.39, 1.29 | 0.275 | 0.41 | 0.17, 0.85 | 0.028 |
| Other | 0.42 | 0.29, 0.61 | <0.001 | 1.16 | 0.60, 2.16 | 0.641 |
| Elixhauser score | 1.01 | 1.00, 1.01 | 0.001 | 1.02 | 1.01, 1.03 | <0.001 |
| 1 OR = Odds Ratio, CI = Confidence Interval | ||||||
Table. Logistic regression models demonstrating the factors associated with undergoing cemented fixation for hemiarthroplasty (left) and THA (right). In general, increased age, female sex, and worse baseline health status (as approximated by Elixhauser score) were associated with increased odds of cementation. For THA specifically, both private insurance and Worker’s Compensation cases were associated with decreased odds of cementation.
Odds of 3-month mortality
| Characteristic | Hemiarthroplasty | THA | ||||
|---|---|---|---|---|---|---|
| OR1 | 95% CI1 | p-value | OR1 | 95% CI1 | p-value | |
| Fixation | ||||||
| Uncemented | — | — | — | — | ||
| Cemented | 1.37 | 1.16, 1.62 | <0.001 | 1.08 | 0.64, 1.80 | 0.768 |
| Age (years) | 1.03 | 1.02, 1.03 | <0.001 | 1.03 | 1.00, 1.05 | 0.021 |
| Sex | ||||||
| Male | — | — | — | — | ||
| Female | 0.59 | 0.50, 0.70 | <0.001 | 0.57 | 0.34, 0.94 | 0.026 |
| Elixhauser score | 1.09 | 1.08, 1.10 | <0.001 | 1.12 | 1.09, 1.15 | <0.001 |
| 1 OR = Odds Ratio, CI = Confidence Interval | ||||||
Table. Logistic regression models demonstrating odds of mortality within 3 months of surgery for hemiarthroplasty (left) and THA (right). For patients undergoing hemiarthroplasty, when controlling for age, sex, and Elixhauser score, the main effect of cemented fixation was associated with increased odds of 3 month mortality. Cementation was not associated with increased odds of 3 month mortality for patients who underwent THA.