TABLE III.

Distribution of Individuals in Prevalence Pool by Age Group and Time Since Initial Procedure

	Total Hip Replacement*				Total Knee Replacement*
Age Group (yr)	<10 Yr	10-20 Yr	>20 Yr	Total No. Hip Arthroplasty	<10 Yr	10-20 Yr	>20 Yr	Total No. Knee Arthroplasty
<50	136,395	47,721	38,160	222,276	104,308	28,968	40,894	174,170
50-59	280,584	64,084	38,849	383,517	537,467	47,092	39,909	624,468
60-69	450,553	125,750	49,113	625,416	1,117,588	188,681	44,424	1,350,693
70-79	447,920	168,097	65,119	681,136	1,046,717	348,568	68,605	1,463,890
80-89	294,119	165,978	73,951	534,048	547,054	323,444	80,444	950,942
≥90	40,754	43,969	21,699	106,422	50,865	67,476	18,117	136,458
All	1,650,325 (65%)	615,599 (24%)	286,891 (11%)	2,552,815	3,403,999 (72%)	1,004,229 (21%)	292,393 (6%)	4,700,621

^*Values are presented as the number of individuals, with the percentage of the total in parentheses.