| non-PHO (n = 101) | PHO (n = 73) | P value |
---|---|---|---|
No. of patients, n | 74 | 64 | – |
No. of surgical levels, n | Â | Â | Â |
 Single-level | 59 | 43 | 0.949 |
Level distribution | Â | Â | 0.516 |
 C3/4 | 7 | 3 |  |
 C4/5 | 17 | 18 |  |
 C5/6 | 62 | 44 |  |
 C6/7 | 15 | 8 |  |
Age, years | 43.10 ± 7.94 | 45.23 ± 8.41 | 0.110 |
Sex (M/F) | 47/54 | 38/35 | 0.472 |
BMI | 23.43 ± 2.87 | 23.36 ± 2.39 | 0.884 |
Blood loss, ml | 53.81 ± 28.05 | 53.84 ± 34.27 | 0.647 |
Follow-up, months | 48.43 ± 20.62 | 55.97 ± 28.23 | 0.276 |
Milling angle | 0.89 ± 3.52 | 0.83 ± 4.12 | 0.590 |
Mean depth of prosthesis, mm | 15.31 | 15.42 | 0.686 |
Mean height of prosthesis, mm | 5.61 | 5.63 | 0.980 |
Prosthesis-endplate depth ratio, % | 94.92 ± 3.26 | 92.13 ± 3.75 |  < 0.001* |
Post-operative disc height change, mm | 1.76 ± 0.99 | 2.56 ± 1.04 |  < 0.001* |
Anterior bone loss | 62 | 45 | 0.973 |