Time trends and risk factors for perioperative complications in total ankle arthroplasty: retrospective analysis using a national database in Japan

Table 3 Comparison of perioperative outcomes between ankle arthrodesis and total ankle arthroplasty groups (A), and adjusted coefficient of determination and odds ratio of major outcomes in total ankle arthroplasty group using ankle arthrodesis group as a control (B)

A.
	Total (n = 2775)	Ankle arthrodesis (n = 2310)	Total ankle arthroplasty (n = 465)	P-value
Length of stay (days), mean ± SD	41.8 ± 28.2	42.8 ± 29.1	36.9 ± 23.6	< 0.001 ^a
Hospitalization costs (dollars), mean ± SD	16111 ± 8002	15123 ± 8085	21019 ± 7595	< 0.001 ^a
Costs of operation (dollars), mean ± SD	6196 ± 2635	5063 ± 2576	11827 ± 2927	< 0.001 ^a
Additional procedure during hospitalization	90 (3.2 %)	76 (3.3 %)	14 (3.0 %)	0.756
Wound treatment	68 (2.5 %)	54 (2.3 %)	14 (3.0 %)	0.392
Skin graft or flap	18 (0.6 %)	16 (0.7 %)	2 (0.4 %)	0.520
Limb amputation	1 (0.04 %)	1 (0.04 %)	0 (0.00 %)	0.654
Negative pressure wound therapy	8 (0.3 %)	6 (0.3 %)	2 (0.4 %)	0.525
Blood transfusion (number of patients)	85 (3.1 %)	61 (2.6 %)	24 (5.2 %)	0.004 ^a
In-hospital death	2 (0.07 %)	2 (0.09 %)	0 (0.00 %)	0.999
B.
	Coefficient	95 % CI	P-value
Length of stay (days)	−6.9	−10.0 to -3.7	< 0.001 ^b
Hospitalization costs (dollars)	5531	4647–6417	< 0.001 ^b
Costs of operation (dollars)	6577	6274–6881	< 0.001 ^b
	Odds ratio	95 % CI	P-value
Additional procedure during hospitalization	0.85	0.43–1.68	0.634
Blood transfusion (number of patients)	1.40	0.77–2.53	0.270

^aThe values in bold indicate significant differences at the 0.005 (=0.05/10) significance level
^bThe values in bold indicate significant differences at the 0.05 significance level

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