Table 3.

Demographic profiles of overall patient population, and study groups stratified by year of index surgery

Demographic	All patients	Surgery before 1990	Surgery in 1990 or later
Number of studies	67	28	9
Total number of patients	2,574	944	395
Total number of hips	3,258	1,209	458
Gender distribution (male:female)	1,564:1,027	437:452	281:114
Weighted mean age (years)	44 (range, 16–86)	45 (range, 16–90)	45 (range, 15–77)
Weighted mean follow-up (years)	8 (range, 0.7–28)	9 (range, 1–28)	6 (range, 1–11)
Fixation (cemented, cementless, hybrid, reverse hybrid)	39%, 53%, 8%, <1%	71%, 28%, 0%, 1%	0%, 89%, 11%, 0%
Revision rate	13% (range, 0–50%)	17% (range, 0–50%)	3% (range, 0–7%)
Revision rate per 100 observed implant years	1.5	1.9	0.5
Years of index surgery	1962–2006	1962–1989	1991–2006