Cnull, control group-surgery only (no spinal attachment units placed);
Csau, control group-spinal attachment units placed during surgery;
CFG, combined fixation group;
ASD, articular surface degeneration;
P values from paired
t test or Wilcoxon matched-pairs signed-rank test. Paired
t test used for nominal data that was Gaussian in distribution; Wilcoxon test used
for ordinal data (0–3 scale) or when nominal data was not Gaussian in distribution.
§Number of Z joints with osteophytes/animal (degeneration occurrence parameter).