Occult Infection in Aseptic Joint Loosening and the Diagnostic Role of Implant Sonication

Table 1

Comparison between the study groups (comparison by Chi-square test and ANOVA means comparison).

Factor	Aseptic loosening = 54	Control = 52	value	Odds ratio
Male sex	33 (61%)	21 (40%)	0.033
Mean age at index arthroplasty (yrs)	57.4	60.4	0.274
Mean age at revision arthroplasty (yrs)	72.3	70.7	0.452
Mean number of years since index operation (95% CI)	14.0 (11.2–16.8)	10.3 (8.1–12.5)	0.054
Joint type
Hip	37 (70%)	40 (75%)	0.51
Knee	16 (30%)	13 (25%)
Cemented implants	25 (46%)	22 (42%)	0.073
Smoking history	7 (13%)	1 (2%)	0.007	7.6
Indication for index replacement
Degenerative	45 (83%)	42 (81%)	0.823
Inflammatory arthritis	3 (6%)	3 (6%)
Posttraumatic arthritis	4 (7%)	3 (6%)
Other	2 (4%)	4 (8%)