Patient characteristics

Knee » Patient characteristics » By type of knee prosthesis

TABLE Patient characteristics of all patients with a registered primary knee arthroplasty by type of knee arthroplasty in the Netherlands in 2019

TKA UKA PFA Total¹
N (n=25,859) (n=4,888) (n=175) (n=30,968)
Mean age (years) (SD) 69.1 (8.8) 64.8 (8.5) 55.0 (10.2) 68.3 (9.0)
Age (years) (%)
  <50 2 3 27 2
  50-59 13 26 45 15
  60-69 34 40 18 35
  70-79 40 27 9 38
  ≥80 11 4 1 10
Gender (%)
  Men 37 45 26 38
  Women 63 55 74 62
ASA score (%)
  I 11 18 29 12
  II 64 67 63 65
  III-IV 25 15 8 23
Type of hospital (%)
  General 84 76 83 83
  UMC 2 1 1 2
  Private 14 23 16 15
Diagnosis (%)
  Osteoarthritis 97 98 96 97
  Post-traumatic 2 0 4 1
  Rheumatoid arthritis 1 0 0 1
  Osteonecrosis 0 1 0 1
  Other 0 0 0 0
Charnley-score (%)
  A One knee joint affected 38 51 59 40
  B1 Both knee joints affected 35 31 28 34
  B2 Contralateral knee joint with a total knee prosthesis 23 17 12 22
  C Multiple joints affected or chronic disease that affects quality of life 4 1 1 4
Mean Body Mass Index (kg/m²) (SD) 29.7 (5.4) 29.1 (5.8) 28.4 (5.0) 29.6 (5.5)
Body Mass Index (kg/m²) (%)
  Underweight (≤18,5) 0 0 0 0
  Normal weight (>18,5-25) 17 18 23 17
  Overweight (>25-30) 41 45 45 42
  Obesity (>30-40) 39 35 30 38
  Morbid obesity (>40) 3 2 2 3
Smoking (%)
  No 92 90 89 92
  Yes 8 10 11 8

¹ Also contains 26 (0.08%) primary knee arthroplasties that were registered as other and 20 (0.06%) primary knee arthroplasties of which the type of prosthesis had not been registered.
TKA: total knee arthroplasty; UKA: unicondylar knee arthropalsty; PFA: patellofemoral knee arthroplasty; General: general hospital; UMC: university medical centre; Private: private hospital; SD: standard deviation.

© LROI 2020

Knee » Patient characteristics » By diagnosis

TABLE Patient characteristics of all patients with a registered primary knee arthroplasty by type of diagnosis in the Netherlands in 2019

Osteoarthritis Post-traumatic Rheumatoid arthritis Osteonecrosis Total
N (n=29,862) (n=413) (n=314) (n=161) (n=30,968)
Mean age (years) (SD) 68.5 (8.8) 63.0 (10.2) 65.6 (11.0) 68.5 (10.7) 68.3 (9.0)
Age (years) (%)
  <50 2 9 6 3 2
  50-59 15 27 21 17 15
  60-69 35 37 33 29 35
  70-79 38 22 31 38 38
  ≥80 10 5 9 13 10
Gender (%)
  Men 38 41 24 33 38
  Women 62 59 76 67 62
ASA score (%)
  I 12 18 2 12 12
  II 65 65 60 65 65
  III-IV 23 17 38 23 23
Type of hospital (%)
  General 83 78 88 86 83
  UMC 2 9 6 2 2
  Private 15 13 6 12 15
Charnley-score (%)
  A One knee joint affected 40 76 23 71 40
  B1 Both knee joints affected 35 12 36 16 34
  B2 Contralateral knee joint with a total knee prosthesis 22 8 20 8 22
  C Multiple joints affected or chronic disease that affects quality of life 3 4 21 5 4
Mean Body Mass Index (kg/m²) (SD) 29.6 (5.5) 28.4 (5.0) 28.7 (5.3) 28.7 (4.3) 29.6 (5.5)
Body Mass Index (kg/m²) (%)
  Underweight (≤18,5) 0 0 1 0 0
  Normal weight (>18,5-25) 17 27 25 20 17
  Overweight (>25-30) 42 40 36 46 42
  Obesity (>30-40) 38 29 35 33 38
  Morbid obesity (>40) 3 4 3 1 3
Smoking (%)
  No 92 83 91 87 92
  Yes 8 17 9 13 8

Please note: In 2019, 126 (0.4%) patients had a primary knee arthroplasty after a diagnosis that is not listed in the table. Of 92 (0.3%) primary knee arthroplasties the diagnosis was not registered.
General: general hospital; UMC: university medical centre; Private: private hospital; SD: standard deviation.

© LROI 2020

Knee » Patient characteristics » Age category 2010-2019

FIGURE Trend (proportion [%] per year) in age category in primary total knee arthroplasties in the Netherlands in 2010-2019

Year

Age category (%)

<50
2.63
2.89
2.79
2.64
2.38
2.41
2.01
2.20
1.77
1.50
2.28
2.28

50-59
14.92
14.82
15.57
15.06
14.75
14.89
14.39
14.37
13.98
13.15
14.55
14.55

60-69
34.49
34.61
35.86
36.68
37.10
36.07
36.51
35.07
34.14
34.19
35.48
35.48

70-79
34.33
34.53
33.65
33.99
34.14
35.06
35.86
36.72
38.33
39.69
35.77
35.77

>80
13.63
13.15
12.13
11.63
11.63
11.58
11.23
11.65
11.78
11.46
11.91
11.91

Total (n):
232,474
18,484
19,483
21,673
22,269
24,214
24,236
24,865
25,553
25,842
25,855

TKA: total knee arthroplasty.

© LROI 2020

Knee » Patient characteristics » Previous surgery 2014-2019

TABLE Trend (proportion [%] per year) in previous surgeries to the same joint in patients who underwent a primary knee arthoplasty in the Netherlands in 2014-2019

Year 2014 2015 2016 2017 2018 2019 Total
Primary knee arthroplasty (n) 26,033 26,477 27,806 29,297 28,258 27,982 165,853
Previous surgery to the relevant knee (total)
Proportion¹ (%) 		 35.7 34.5 33.4 28.0 25.2 24.5 30.1
Meniscectomy 28.4 27.3 26.6 22.3 20.6 19.9 24.1
Arthroscopy 17.7 18.9 19.3 17.1 15.6 15.3 17.3
Osteotomy 3.0 3.0 2.8 2.9 2.8 2.5 2.8
Osteosynthesis 1.7 1.7 1.4 1.5 1.5 1.6 1.6
ACL reconstruction 1.3 1.5 1.5 1.5 1.4 1.5 1.5
Synovectomy 1.2 1.2 1.0 0.8 0.6 0.6 0.9
Other 3.3 2.9 3.1 3.0 3.0 3.4 3.1

¹ A patient may have undergone multiple previous surgeries to the same joint. As such, the total proportion is more than the total proportion of patiens with one or more previous surgeries to the same joint.

© LROI 2020