Table 5 The collapse rate of femoral head within 5 years based on the matrix model
|  | One point (n = 25) | Two point (n = 62) | Four point (n = 85) | Eight point (n = 30) | Statistical value | P value |
|---|---|---|---|---|---|---|
n/% | n/% | n/% | n/% | |||
1-year collapse | 1/4.0 | 15/24.2 | 31/36.5 | 12/40.0 | χ2 = 12.295 | 0.006** |
3-year collapse | 1/4.0 | 18/29.0 | 46/54.1 | 19/63.3 | χ2 = 29.897 | 0.000*** |
5-year collapse | 1/4.0 | 20/32.3 | 50/58.8 | 27/90.0 | χ2 = 50.680 | 0.000*** |