Table 5: The comparison outcome of total patients and patients over 2-year follow-up.

Number of patientsFollow-up (months)Rate of loosening
per patient (%)
Rate of loosening
per screw (%)
ClinicalRadiological

All patients29146.4 ± 22.732.6 ± 21.221.38.4
Follow-up >2 years206 51.1 ± 20.840.7 ± 19.720.48.2