Help in mixed models SPSS

#1
Hello!

We are investigating the migration patterns of a surgical prosthesis. We do this by taking X-rays and noting the migration along the 3 orthogonal axes, where T0 is the state immediately after implantation.

Unfortunately we have missing data and I cannot use repeated measures ANOVA. The data set looks something like this, for example the migration on Y-axis (numbers express the migration in mm, negative value means that prosthesis moves down, positive up).

ID | T0 | T1 | T2 | T3 | T4
1 | 0 | -0.2 | -0.3 | x | 0
2 | 0 | 0.1 | 0.2 | 0.2 | 0.3
3 | 0 | 0.3 | 0.4 | x | 0.5
4 | 0 | x | 0.1 | 0.2 | 0.2
5 | 0 | -0.1 | 0 | 0.1 | 0.2

I would like to know when the migration will become significant and if this migration will eventually stabilise. I will probably have to use mixed models for this, but I would like to have tips on which settings to use in SPSS and how this can best be read.

Thank you very much!