Bariatric surgery prior to total knee arthroplasty is not associated with lower risk of revision: a register-based study of 441 patients

Figures & data

Figure 1. Flow-chart of the study.

Table 1. Patient characteristics

	Restricting for BMI before BS		Restricting for BMI prior to TKA
	BS group	noBS group	BS group	noBS group
Factor	n = 441	n = 25,707	n = 441	n = 95,948
Women ^a	336 (76)	16,452 (64)	336 (76)	52,771 (55)
Age ^b	55 (37–74)	65 (39–76)	57 (39–76)	66 (39–76)
BMI ^b	43 (32–63)	35 (32–50)	35 (32–50)	29 (17–50)

^a Count (%)

^b Mean (range)

Table 2. Adjusted hazard ratios (aHR) for the risk of revision for infection and any reasons for revision when using BMI before the BS

	Revision for infection	Revision for any reasons
Variable	aHR (95% CI)	aHR (95% CI)
noBS group	Reference	Reference
BS group	0.9 (0.4–2.0)	1.2 (0.8–2.0)

Table 3. Adjusted hazard ratios (aHR) for the risk of revision for infection and any reason for revision when using BMI before the TKA

	Revision for infection	Revision for any reasons
Variable	aHR (95% CI)	aHR (95% CI)
noBS group	Reference	Reference
BS group	2.2 (1.1–4.7)	1.3 (0.9–2.1)