Obesity and total ankle arthroplasty: Contraindication or consideration

Table 1 Characteristics of the included studies

Ref.	Design	Level of evidence	Patients (n)	Age (years), mean	Gender (n of males)	Obese patients (n)	Mean follow-up
Bakaes et al[10], 2024	NSQIP database	III	2026	NR	NR	26	30 days
Barg et al[19], 2011	Single institution	IV	118	59.8 ± 11.6	61	118	67.7 ± 27.0 months
Best et al[17], 2022	NSQIP database	III	294	64 ± 12	132	133	30 days
Bouchard et al[21], 2015	Single institution	III	87	62.44 ± 8.42	39	39	3.92 years
Cottom et al[13], 2019	Single institution	III	97	66.4	43	44	26.3 months
Cunningham et al[16], 2018	Single institution	IV	1024	63 ± 10.5	528	278	90 days
Sy et al[15], 2025	NSQIP database	III	1704	52.2 ± 9.5	937	899	30 days
Gross et al[20], 2016	Single institution	III	455	62.5 ± 8.2	204	189	3.7 years
Jennison et al[11], 2023	National registry (United Kingdom)	III	5562	67.8 ± 10.1	3308	1497	5.0 years
Kim et al[6], 2023	Single institution	III	1093	63.7 ± 8.52	558	478	5.6 years
Kwon et al[18], 2023	NSQIP database	III	1333	63.3 ± 11.2	707	NR	30 days
Sambandam et al[14], 2023	NIS database	III	5087	65.1 ± 10.3	2748	1033	Inpatient
Schipper et al[5], 2016	Single institution	III	97	58.2 ± 9.1	52	49	8.2 ± 2.0 years
Werner et al[12], 2015	PearlDiver database	III	5361	NR	2593	1115	7.0 years (revision), 90 days (complications)

Values are presented as reported in the original studies. Continuous variables are expressed as mean ± SD. NR: Not reported; NSQIP: National Surgical Quality Improvement Program; NIS: National Inpatient Sample.

Table 2 Complication rates in total ankle replacement related to obesity

Ref.	Overall rate			Infection/wound complications			90-day readmission			ARF
	Obese	Non-obese	P value	Obese	Non-obese	P value	Obese	Non-obese	P value	Obese	Non-obese	P value
Gross et al[20], 2016	11%	16.5%	0.196	0.5%	2.26%	0.431	NR	NR	NR	NR	NR	NR
Bouchard et al[21], 2015	Similar	Similar	0.48	0%	2.1%	NS	NR	NR	NR	NR	NR	NR
Cunningham et al[16], 2018	NR	NR	NR	1.82%	3.85%	0.28	1.32%	4.1%	0.99	NR	NR	NR
Cottom et al[13], 2019	11.4%	18.9%	0.308	NR	NR	NS	NR	NR	NR	NR	NR	NR
Kim et al[6], 2023	21.8%	27%	0.126	0.4%	1.3%	0.274	NR	NR	NR	NR	NR	NR
Best et al[17], 2022	3.8%	2.5%	0.5301	NR	NR	NR	NR	NR	NR	NR	NR	NR
Kwon et al[18], 2023	Non-associated with BMI		NR	0.6%		Non-associated with BMI	1.4%		Non-associated with BMI2	NR	NR	NR
Bakaes et al[10], 2024	2.6%	12%	0.436	7.8%	15.7%	NS	NR	NR	NR	0%	0%	> 0.05
Werner et al[12], 2015	Significantly increased risk for obese patients		< 0.001	4.7%	2.2%	< 0.001	NR	NR	NR	NR	NR	NR
Sambandam et al[14], 2023	NR	NR	NR	NR	NR	NR	NR	NR	NR	15	22	0.0023
Sy et al[15], 2025	NR	NR	NR	NR	NR	NR	BMI > 30 is associated with non-home dischargea,4		< 0.01	NR	NR	NR

^aP < 0.01.

¹Odds ratio = 1.5, 95% confidence interval: 0.40-5.8.

²Odds ratio = 0.95, 95% confidence interval: 0.87-1.03.

³Odds ratio = 2.70, 95% confidence interval: 1.4-5.22.

⁴Odds ratio = 1.93, 95% confidence interval: 1.29-2.89.

NR: Non-reported; NS: Non-significant; ARF: Acute renal failure; BMI: Body mass index.

Table 3 Revision rates and implant survival in patients undergoing total ankle replacement

Ref.	Revision rate			Survivorship
	Obese	Non-obese	P value	Obese	Non-obese	P value
Schipper et al[5], 2016	42.9%	31.3%	0.041	NS2	NS2	0.3
Barg et al[19], 2011	19.5%	-	NR	93%3	-	NR
Gross et al[20], 2016	4.1%	3.0%	0.861	NR	NR	NR
Bouchard et al[21], 2015	17.9%	8.4%	0.48	4.5 years4	4.6 years4	0.47
Cottom et al[13], 2019	0%	0%	-	NR	NR	NR
Kim et al[6], 2023	No association of BMI and implant failure		0.896	NR	NR	NR
Werner et al[12], 2015	Significantly increased risk for obese patients		0.0045	NR	NR	NR
Jennison et al[11], 2023	NR	NR	-	88.9%	94.0%	0.026

¹Adjusted odds ratio = 2.8, 95% confidence interval: 1.04-7.53.

²5 years of survivorship.

³At 6 years (95% confidence interval: 87.2%-94.3%).

⁴Mean operation-free survival time.

⁵Odds ratio =1.6, 95% confidence interval: 1.2-2.2.

⁶Hazard ratio = 1.76, 95% confidence interval: 1.09-2.85.

Values of follow-up are reported as percentages, years or months according to the original study. NR: Non-reported; NS: Non-significant; BMI: Body mass index.

Table 4 Functional outcomes in obese and non-obese patients undergoing total ankle arthroplasty

Ref.	Functional measure	Preoperative		Statistical significance of difference (P value)	Postoperative		Main finding	Statistical significance of difference (P value)
		Obese	Non-obese		Obese	Non-obese
Gross et al[20], 2016	SMFA function	88.0 ± 17.4	81.9 ± 18.2	0.002	61.7 ± 19.9	54.9 ± 20.0	Obese patients had lower absolute functional scores compared with non-obese patients at final follow-up	0.009
	FADI	61.2 ± 7.7	54.5 ± 14.1	0.014	24.5 ± 17.3	16.2 ± 15.7		0.003
	FAOS pain	42.0 ± 18.4	46.3 ± 17.2	0.795	77.6 ± 18.5	84.8 ± 17.3		0.038
	SF-36 total	44.7 ± 17.5	49.5 ± 17.9	0.03	63.6 ± 20.3	73.7 ± 20.8		< 0.001
Kim et al[6], 2023	FADI, mean	58.17 ± 8.35	52.62 ± 14.32	0.008	21.65 ± 16.26	17.71 ± 16.61	Obese patients reported worse preoperative and postoperative PROMs overall	0.041
	SMFA, mean	37.92 ±13.13	33.18 ± 13.60	0.001	20.13 ± 13.69	15.36 ± 14.12		< 0.001
	SF-36, mean	47.10 ± 16.37	52.93 ± 18.07	0.002	64.78 ± 19.96	73.44 ± 19.92		< 0.001
	AOFAS hindfoot, mean	39.38 ± 15.73	42.33 ± 17.15	0.213	73.94 ± 15.8	77.74 ± 15.38		0.039
	FAOS pain, mean	35.70 ± 16.98	46.85 ± 18.42	< 0.001	76.28 ± 19.88	81.84 ± 18.85		0.006
Bouchard et al[21], 2015	AOS pain	55.88 ± 18.00	52.92 ± 19.41	0.47	19.59 ± 18.50	19.00 ± 16.80	Ankle arthroplasty significantly and similarly improved pain and disability scores in both obese and non-obese groups	0.93
	AOS disability	68.64 ± 14.09	59.79 ± 19.57	NS	28.21 ± 21.51	27.20 ± 19.33		0.82
	SF-36-PCS	29.54 ± 6.92	34.48 ± 9.05	0.01	39.21 ± 10.30	40.30 ± 9.84		0.62
	SF-36-MCS	50.86 ± 12.72	53.70 ± 11.24	0.32	50.51 ± 13.37	54.05 ± 9.27		0.30

Values of outcomes are reported as mean ± SD according to the original study. FADI: Foot and Ankle Disability Index; FAOS: Foot and Ankle Outcome Score; SF-36: 36-Item Short Form Health Survey; SMFA: Short Musculoskeletal Function Assessment; AOFAS: American Orthopaedic Foot and Ankle Society score; AOS: Ankle Osteoarthritis Scale; SF-36-PCS: 36-Item Short Form Health Survey Physical Component Summary; SF-36-MCS: 36-Item Short Form Health Survey Mental Component Summary; NS: Non-significant.

Table 5 Newcastle-Ottawa Scale for included studies

Ref.	Selection (0-4)	Comparability (0-2)	Outcome (0-3)	Total NOS	Risk of bias
Bakaes et al[10], 2024	4	1	3	8/9	Low
Barg et al[19], 2011	3	0	3	6/9	Moderate
Best et al[17], 2022	4	2	3	9/9	Low
Bouchard et al[21], 2015	4	1	3	8/9	Low
Cottom et al[13], 2019	4	0	3	7/9	Moderate
Cunningham et al[16], 2018	4	2	3	9/9	Low
Sy et al[15], 2025	4	2	2	8/9	Low
Gross et al[20], 2016	4	0	3	7/9	Moderate
Jennison et al[11], 2023	4	2	2	8/9	Low
Kim et al[6], 2023	4	1	2	7/9	Moderate
Kwon et al[18], 2023	4	2	2	8/9	Low
Sambandam et al[14], 2023	4	0	2	6/9	Moderate
Schipper et al[5], 2016	4	2	2.5	8/9	Low
Werner et al[12], 2015	3.5	0	2.5	6/9	Moderate

NOS: Newcastle-Ottawa Scale.