Table 3.
Post-operative outcomes in the different BMI groups at different time points.
| BMI group | Significance | ||||
|---|---|---|---|---|---|
| Normal | Overweight | Obese (class 1) | Obese (class 2) | p value | |
| 1-year | |||||
| 1 year OKS |
42.7 (SD 6.1) 45.0 (IQR 6.0) |
42.9 (SD 5.8) 45.0 (IQR 6.0) |
41.4 (SD 6.8) 44.0 (IQR 7.0) |
39.0 (SD 9.5) 42.0 (IQR 12.0) |
< 0.001 |
| 1 year Tegner |
3.1 (SD 1.2) 3.0 (IQR 0.0) |
3.3 (SD 1.2) 3.0 (IQR 1.0) |
3.0 (SD 1.1) 3.0 (IQR 2.0) |
2.6 (SD 1.2) 3.0 (IQR 1.0) |
< 0.001 |
| 1 year AKSS-O |
93.4 (SD 10.3) 95.0 (IQR 7.0) |
93.5 (SD 9.3) 95.0 (IQR 7.0) |
90.2 (SD 11.7) 94.0 (IQR 8.0) |
87.1 (SD 15.7) 94.0 (IQR 14.0) |
< 0.001 |
| 1 year AKSS-F |
87.9 (SD 14.3) 100.0 (IQR 20.0) |
87.9 (SD 14.8) 100.0 (IQR 20.0) |
84.2 (SD 14.3) 80.0 (IQR 17.5) |
77.6 (SD 19.8) 80.0 (IQR 30.0) |
< 0.001 |
| 1 year Charnley score |
28.6% A 42.2% B 29.2% C |
26.6% A 50.0% B 23.4% C |
16.3% A 51.2% B 32.5% C |
16.4% A 40.4% B 43.3% C |
0.003 |
| 1 year max flexion (°) |
132.4 (SD 10.5) 134.5 (IQR 14.0) |
129.3 (SD 9.1) 130.0 (IQR 9.0) |
124.9 (SD 8.4) 125.0 (IQR 11.0) |
119.2 (SD 13.2) 120.0 (IQR 15.0) |
< 0.001 |
| 1 year max extension |
2.6 (SD 3.6) 2.0 (IQR 5.0) |
3.1 (SD 3.9) 3.0 (IQR 5.0) |
4.1 (SD 4.4) 4.0 (IQR 6.0) |
3.3 (SD 4.9) 2.5 (IQR 6.5) |
0.03 |
| 2-year | |||||
| 2 years OKS |
43.1 (SD 6.9) 46.0 (IQR 5.0) |
43.8 (SD 5.2) 46.0 (IQR 5.0) |
43.0 (SD 5.6) 45.0 (IQR 6.0) |
40.7 (SD 8.5) 44.0 (IQR 11.0) |
0.003 |
| 2 years Tegner |
3.1 (SD 1.3) 3.0 (IQR 2.0) |
3.5 (SD 1.3) 3.0 (IQR 1.0) |
3.1 (SD 1.1) 3.0 (IQR 1.0) |
2.7 (SD 1.3) 3.0 (IQR 1.0) |
< 0.001 |
| 2 years AKSS-O |
92.8 (SD 11.9) 95.0 (IQR 6.5) |
94.1 (SD 8.9) 97.0 (IQR 7.0) |
93.8 (SD 8.1) 95.0 (IQR 6.0) |
91.4 (SD 11.1) 95.0 (IQR 7.0) |
0.048 |
| 2 years AKSS-F |
87.6 (SD 14.7) 100.0 (IQR 20.0) |
87.7 (SD 14.6) 90.0 (IQR 20.0) |
84.8 (SD 15.9) 85.0 (IQR 30.0) |
79.0 (SD 20.2) 80.0 (IQR 30.0) |
< 0.001 |
| 2 years Charnley score |
23.1% A 49.2% B 26.7% C |
22.8% A 48.8% B 28.4% C |
11.3% A 50.0% B 38.7% C |
20.4% A 35.7% B 43.9% C |
0.003 |
| 2 years max flexion |
133.2 (SD 9.0) 134.0 (IQR 10.0) |
129.7 (SD 8.6) 130.0 (IQR 11.0) |
127.1 (SD 8.8) 128.0 (IQR 10.0) |
120.0 (SD 12.2) 122.0 (IQR 14.0) |
< 0.001 |
| 2 years max extension |
2.0 (SD 3.7) 0.5 (IQR 3.0) |
2.8 (SD 3.5) 2.0 (IQR 5.0) |
3.5 (SD 3.9) 3.0 (IQR 5.0) |
2.9 (SD 5.5) 1.0 (IQR 7.0) |
0.08 |
| 5-year | |||||
| 5 years OKS |
43.1 (SD 6.6) 46.0 (IQR 6.0) |
43.9 (SD 5.9) 46.0 (IQR 5.0) |
41.0 (SD 7.8) 44.0 (IQR 9.0) |
40.5 (SD 8.0) 44.0 (IQR 11.0) |
< 0.001 |
| 5 years Tegner |
3.1 (SD 1.4) 3.0 (IQR 2.0) |
3.3 (SD 1.4) 3.0 (IQR 1.0) |
2.8 (SD 1.3) 3.0 (IQR 1.0) |
2.6 (SD 1.4) 3.0 (IQR 1.0) |
< 0.001 |
| 5 years AKSS-O |
93.6 (SD 8.3) 95.0 (IQR 7.0) |
94.8 (SD 8.2) 98.0 (IQR 7.0) |
91.2 (SD 11.8) 95.0 (IQR 7.5) |
92.4 (SD 9.9) 95.0 (IQR 9.0) |
0.01 |
| 5 years AKSS-F |
84.3 (SD 17.0) 90.0 (IQR 20.0) |
88.0 (SD 15.4) 100.0 (IQR 20.0) |
80.1 (SD 16.3) 80.0 (IQR 30.0) |
74.3 (SD 22.6) 80.0 (IQR 20.0) |
< 0.001 |
| 5 years Charnley score |
19.4% A 41.8% B 38.8% C |
11.4% A 49.6% B 39.0% C |
11.7% A 43.2% B 45.1% C |
18.8% A 34.4% B 46.9% C |
0.44 |
| 5 years max flexion |
132.7 (SD 10.5) 134.5 (IQR 14.0) |
129.4 (SD 8.1) 130.0 (IQR 10.0) |
125.1 (SD 9.5) 125.0 (IQR 15.0) |
121.8 (SD 10.5) 122.5 (IQR 13.0) |
< 0.001 |
| 5 years max extension |
2.5 (SD 4.2) 2.0 (IQR 5.0) |
2.0 (SD 4.1) 1.0 (IQR 5.0) |
2.2 (SD 3.8) 2.0 (IQR 5.0) |
2.9 (SD 4.7) 0.0 (IQR 5.0) |
0.56 |
| 10-year | |||||
| 10 years OKS |
42.0 (SD 5.6) 43.0 (IQR 11.0) |
44.3 (SD 4.9) 46.0 (IQR 6.0) |
40.1 (SD 9.7) 44.0 (IQR 9.0) |
36.4 (SD 11.4) 38.0 (IQR 10.0) |
0.04 |
| 10 years Tegner |
2.5 (SD 1.1) 3.0 (IQR 1.0) |
3.3 (SD 1.0) 3.0 (IQR 1.0) |
2.3 (SD 1.3) 2.5 (IQR 2.0) |
2.6 (SD 1.5) 3.0 (IQR 1.0) |
0.08 |
| 10 years AKSS-O |
90.5 (SD 12.1) 94.0 (IQR 10.0) |
95.6 (SD 4.8) 96.5 (IQR 7.0) |
87.5 (SD 17.5) 97.5 (IQR 29.0) |
83.1 (SD 16.4) 93.0 (IQR 27.0) |
0.09 |
| 10 years AKSS-F |
80.9 (SD 16.0) 80.0 (IQR 30.0) |
86.0 (SD 13.9) 90.0 (IQR 20.0) |
67.9 (SD 11.8) 70.0 (IQR 12.5) |
70 (SD 27.1) 75.0 (IQR 30.0) |
0.007 |
| 10 years Charnley score |
12.5% A 31.3% B 56.3% C |
8.6% A 42.8% B 48.6% C |
0.0% A 8.3% B 91.7% C |
0.0% A 11.1% B 88.9% C |
0.24 |
| 10 years max flexion |
133.9 (SD 10.8) 133.0 (IQR 14.0) |
128.5 (SD 9.7) 130.0 (IQR 17.0) |
126.4 (SD 5.0) 125.0 (IQR 8.0) |
125.6 (SD 9.1) 129.0 (IQR 10.0) |
0.12 |
| 10 years max extension |
2.9 (SD 4.9) 1.0 (IQR 7.0) |
3.0 (SD 4.3) 3.0 (IQR 5.0) |
2.6 (SD 3.1) 1.5 (IQR 5.0) |
3.2 (SD 6.2) 5.0 (IQR 8.0) |
0.99 |
PROMs were compared with the Kruskal–Wallis test, Charnley scores with the Chi-squared proportional test and flexion/extension with one-way ANOVA test