Is decreasing mortality in total hip and knee arthroplasty patients dependent on patients’ comorbidity?

Figures & data

Table 1. Number of procedures and characteristics of study population according to comorbidity burden measured with the Charlson comorbidity index (CCI), for total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients. The CCI groups correspond to the following: CCI-none = no comorbid conditions; CCI-low = comorbid conditions equal score 1; CCI-moderate = comorbid conditions equal score 2; and CCI-high = comorbid conditions equal score 3 or higher

	CCI-none	CCI-low	CCI-moderate	CC-high	Total (N)
THA
No. of THAs, n (%)	69,292 (69)	15,022 (15)	10,092 (10)	5,556 (5)	99,962
in 1996–1999	11,511 (77)	1,919 (13)	1,150 (8)	424 (3)	15,004
in 2000–2004	16,988 (71)	3,603 (15)	2,223 (9)	1,129 (5)	23,943
in 2005–2009	21,909 (68)	4,925 (15)	3,316 (10)	1,967 (6)	32,117
in 2010–2013	18,884 (65)	4,575 (16)	3,403 (12)	2,036 (7)	28,898
Female, n (%)	39,281 (57)	8,245 (55)	5,798 (57)	2,890 (52)	56,214
Age at primary
procedure (IQR)	69 (62–75)	72 (65–78)	73 (66–78)	74 (67–79)	70 (63–76)
in 1996–1999	70 (62–76)	73 (66–78)	73 (67–78)	73 (68–78)	71 (63–80)
in 2000–2004	70 (62–76)	72 (65–78)	73 (67–79)	74 (67–79)	70 (63–77)
in 2005–2009	68 (61–75)	71 (64–77)	72 (66–78)	73 (67–79)	69 (62–76)
in 2010–2013)	69 (62–75)	71 (65–77)	72 (67–78)	74 (67–79)	70 (64–76)
LOS (IQR)	6 (3–9)	6 (3–9)	5 (3–9)	6 (3–9)	6 (3–9)
in 1996–1999	11 (9–14)	12 (9–15)	12 (9–14)	13 (10–16)	11 (9–14)
in 2000–2004	7 (9–11)	9 (7–12)	9 (8–12)	10 (8–13)	9 (7–11)
in 2005–2009)	4 (3–6)	5 (4–7)	5 (3–7)	5 (4–8)	5 (3–7)
in 2010–2013	3 (2–3)	3 (2–4)	3 (2–4)	3 (2–5)	3 (2–4)
Fixation, %
cemented	30	33	34	34	31
uncemented	48	45	43	44	47
hybrids	22	22	23	22	22
TKA
No. of TKAs, n (%)	41,013 (64)	11,109 (17)	7,256 (11)	4,340 (7)	63,718
in 1996–1999	2,737 (73)	538 (14)	330 (9)	132 (3)	3,737
in 2000–2004	8,117 (67)	2,114 (17)	1,281 (10)	665 (5)	12,177
in 2005–2009	15,984 (64)	4,331 (17)	2,842 (11)	1,760 (7)	24,917
in 2010–2013	14,175 (62)	4,126 (18)	2,803 (12)	1,783 (8)	22,887
Female (%)	26,782 (65)	6,864 (62)	4,559 (63)	2,436 (56)	40,641
Age at primary
procedure (IQR)	69 (62–76)	71 (64–77)	72 (66–78)	73 (66–78)	70 (63–76)
in 1996–1999	72 (64–77)	72 (66–78)	74 (67–79)	73 (65–78)	72 (65–78)
in 2000–2004	70 (63–77)	71 (64–77)	74 (67–79)	74 (68–79)	71 (64–77)
in 2005–2009	68 (62–75)	71 (64–77)	72 (66–78)	73 (66–79)	76 (63–76)
in 2010–2013	68 (62–75)	70 (64–76)	71 (65–77)	72 (66–77)	69 (63–76)
Median LOS (IQR)	5 (3–8)	5 (3–8)	5 (3–8)	5 (3–8)	5 (3–8)
in 1996–1999	14 (11–16)	14 (11–17)	14 (11–18)	13.5 (10–18)	14 (11–16)
in 2000–2004	10 (8–13)	10 (8–13)	10 (8–13)	11 (8–14)	10 (8–13)
in 2005–2009	5 (3–7)	5 (3–7)	5 (3–7)	6 (4–8)	5 (3–7)
in 2010–2013	3 (2–4)	3 (2–4)	3 (2–4)	3 (3–5)	3 (2–4)
Fixation, %
cemented	76	78	78	77	76
uncemented	8	6	7	6	7
hybrids	16	16	15	17	17

IQR: interquartile range; LOS: length of stay.

Figure 1. The distribution of total hip (left panel) and knee arthroplasty (right panel) procedures according to comorbidity burden.

Figure 2. Development in risk of mortality in total hip (left panel) and knee arthroplasty (right panel) procedures according to comorbidity burden.