Table 2: Comparison of patients with and without screw loosening.

Characteristic Screw loosening value
YesNo

Number of patients42 (20.4%)164 (79.6%)
Age (year)64.6 ± 11.660.1 ± 13.10.03
Sex (F : M)0.99
 Male 2392
 Female1972
BMI24.6 ± 3.225.6 ± 3.80.22
DM11/4230/1640.47
HTN16/4275/1640.47
Smoke3/4215/1640.92
Instrumentation0.48
 1 level15/4271/164
 2 levels27/42135/164
Blood loss (mL)822.6 ± 521.6703.6 ± 544.50.22
Number of screws87 (8.2%)977 (91.8%)
Screw distribution
 L20 (0%)12 (100%)
 L316 (8.1%)182 (91.9%)
 L424 (6.4%)352 (93.6%)
 L532 (8.3%)354 (91.7%)
 S115 (16.3%)77 (83.7%)

Values are presented by mean ± SD.
BMI = body mass index; DM = diabetes mellitus; and HTN = hypertension.