During the period between 1995 and 2011, 996 hemophilia patients were registered in the NHIRD of Taiwan. Among these patients, 103 primary TKR surgeries were performed on 75 patients (7.5%) with severe hemophilic arthropathy (Fig. 1). Sixty-three patients were diagnosed with hemophilia A and the remaining 12 with hemophilia B. Hemophilia patients with factor VIII inhibitor or HIV were not enrolled in the study. Unilateral TKR surgery was performed on 47 patients, whereas 28 patients received bilateral TKR, including 12 simultaneous TKR and 16 staged TKR in two consecutive admissions (Table 1).
Table 1
The prevalence of total knee replacement procedures in hemophiliacs in Taiwan (1997–2011)
| Total (n = 996) | Hemophilia A (n = 830) | Hemophilia B (n = 166) |
Total No. of patient who received TKR | 75 (7.5%) | 63 | 12 |
Total No. of TKR | 103 | 86 | 17 |
Unilateral TKR | 47 | 40 | 7 |
Bilateral TKR | 28 | 23 | 5 |
Simultaneous | 12 | 10 | 2 |
Staged | 16 | 13 | 3 |
Failure | 8 (7.8%) | 8 (9.3%) | 0 (0%) |
Aseptic loosening | 4 (3.8%) | 4 (4.7%) | 0 (0%) |
Deep Infection | 4 (3.8%) | 4 (4.7%) | 0 (0%) |
The mean age of the patients was 32.3 years (range, 17.3–55.7 years) at the time of index surgery, and the mean follow-up duration was 77.9 months (range, 2.3–176.8 months). The mean hospital stay was 14 days (range, 6–36 days). Among the 103 TKR implants, 8 (8.5%) were revised, removed, or converted to a knee arthrodesis at a mean duration of 32.8 months (range, 2.3–95 months) after surgeries. Four cases were derived from aseptic loosening, and 4 were caused by infections. The 10-year prosthesis survivorship was 88.6% (Fig. 2).
We further analyzed the amount of coagulation factors used before and after TKR. Table 3 demonstrates that the mean daily consumption of coagulation factor was 235.7 units (range: 0–2884.3) before the surgery in all hemophilic patients, which increased significantly during the first 6 months after TKR (364.9 units, P = 0.002) but later decreased to 202.1 units after 18 months of surgery (P = 0.633). No significant difference in the daily factor consumption was noted in hemophilic patients before and 18 months after the TKR. Regarding the difference between the two types of hemophilia, less amount of coagulation factor was postoperatively prescribed for patients with hemophilia B than that in hemophilia A in 18 months after TKR (205.9 U/day vs.178.4 U/day, respectively) (Table 3).
To evaluate the cost-effectiveness of TKR surgeries performed on hemophilic patients, the direct costs of factor supplement, total admission costs, length of hospital stay, and PRBC transfusion for the surgeries of simultaneous-bilateral TKR were compared with that of unilateral TKR and staged-bilateral TKR surgeries (Table 2; Fig. 3). For patients receiving unilateral TKR surgery, the mean length of hospital stay was 15 days (range, 7–32 days) and the mean cost of factor supplement was USD 43,543. An average of four packed RBC units was transfused (range: 0–38 U), and the mean total admission cost was USD 48,326 (range, USD 4,165–USD 262,619).
Table 2
Comparisons between unilateral TKR, staged bilateral TKR, and simultaneous bilateral TKR
| Unilateral (n = 46*) | Staged (n = 16) | | | Simultaneous (n = 11*) | P1 | P2 |
| | 1st | 2nd | Total | | | |
Hemophilia A | 39 (84.8) | | | 13 (81.3) | 9 (81.8) | 0.919 | |
Age | | | | | | | |
Median | 32.1 (17.3–55.7) | 32.9 (23.7–49.8) | 37.3 (26.5–54.9) | | 30.0 (24.5–49.7) | | |
< = 30 | 18 (39.1) | 8 (50) | 6 (37.5) | | 6 (54.5) | 0.711 | |
> 30 | 28 (60.9) | 8 (50) | 10 (62.5) | | 5 (45.5) | | |
Era | | | | | | 0.202 | |
Before 2004 | 23 (50.0) | 11 (68.8) | 6 (37.5) | | 6 (54.5) | | |
After 2004 | 23 (50.0) | 5 (31.2) | 10 (62.5) | | 5 (45.5) | | |
Hospitalization days | 15 (7–32) | 12.5 (6–30) | 11 (7–36) | 23.5 (14–53) | 15 (9–20) | 0.703 | 0.001 |
Factor usage (USD) | 43543 (93–258785) | 41805 (7245–86816) | 47912 (17131–255125) | 93878 (34250–328633) | 54737 (18008–126482) | 0.091 | 0.044 |
Transfusion amount | 4 (0–38) | 2 (0–12) | 2 (0–14) | 3 (0–26) | 8 (2–16) | 0.287 | 0.183 |
Admission cost (USD) | 48326 (4165–262619) | 46427 (11515–96956) | 52574 (21636–262011) | 101932 (43067–345933) | 61587 (26159–134497) | 0.096 | 0.023 |
Failure | 7 (15.2) | | | 1 (6.3) | 0 (0) | 0.188 | 1.000 |
P1: Simultaneous vs. Unilateral vs. Staged 1st vs. Staged 2nd |
P2: Simultaneous vs. staged 1st + 2nd, *One patient with inhibitor was excluded from this analysis in both the single and bilateral TKR groups. |
Table 3
Comparison of mean daily factor usage before and after surgery
| Preoperative* | | Postoperative | P value |
Mean | Interval (month) | Mean |
All (n = 75) | 235.7 (0-2884.3) | | 1 | 280.8 (0-3973.6) | 0.067 |
| | | 6 | 364.9 (0-4584.9) | 0.002 |
| | | 18 | 202.1 (0-1671.9) | 0.633 |
Haemophilia A (n = 63) | 235.6 (0-2884.3) | | 1 | 277.9 (0-3973.6) | 0.162 |
| | | 6 | 363.2 (0-4584.9) | 0.007 |
| | | 18 | 205.9 (0-1671.9)) | 0.806 |
Haemophilia B (n = 12) | 413.5 (17.3-615.4) | | 1 | 323.5 (0-2313.0) | 0.155 |
| | | 6 | 410.9 (22.5-1278.3) | 0.064 |
| | | 18 | 178.4 (0-710.1) | 0.323 |
*Mean daily factor usage of 12 months before surgery |
Regarding the bilateral TKRs, the mean length of hospital stay was 15 days (range, 9–20 days) in patients receiving simultaneous-bilateral TKR, and the cumulative hospital stay was 23.5 days (range, 14–53 days) for subjects receiving staged-bilateral TKR surgery (P = 0.001). In addition, the mean expenses of factor supplement cost were USD 54,737 (range, USD 18,008–USD 126,482) and USD 93,878 (range, USD 34,250–USD 328,633) for simultaneous and staged TKRs, respectively (P = 0.044). In comparison with staged-bilateral TKRs, simultaneous procedures exhibited significantly reduced mean total admission cost by a difference of USD 40336 (USD 101,923 versus USD 61,587, P = 0.023) (Fig. 3).