Better implant survival with modern ankle prosthetic designs: 1,226 total ankle prostheses followed for up to 20 years in the Swedish Ankle Registry

Figures & data

Table 1. Distribution of TARs implanted in Sweden during 1993–2016 by year of implantation and prosthetic design

	Early prosthetic designs				Current prosthetic designs
Year	STAR ^a	BP ^b	AES ^c	Hintegra ^d	Mobility ^e	CCI ^f	Rebalance ^g	TM Ankle ^h	Total
1993	6								6
1994	13								13
1995	11								11
1996	8								8
1997	24								24
1998	34								34
1999	25	1							25
2000	45								46
2001	48	21	3	10					48
2002	39	23	17	14					73
2003	25	29	16	4					79
2004	18	13	23	2	9				67
2005	18	11	21	6	21				65
2006	8	7	18		20				67
2007	1	4	17		32	16			46
2008					31	42			69
2009					41	22			73
2010					44	22	21		63
2011					23	31	27		87
2012					32	12	34		81
2013					15	4	37	5	78
2014					1	2	36	11	61
2015				3			23	21	53
2016				9					53
Total	323	109	115	48	269	151	178	37	1,230

a Scandinavian Total Ankle Replacement (Waldemar LINK GmBH, Hamburg, Germany)

b Buechel–Pappas (Wright Cremascoli, Toulon, France)

c Ankle Evolutive System (Biomet, Valence, France)

d Hintegra (Newdeal SA, Lyon, France)

e Mobility (DePuy International, Leeds, UK)

f CCI–Ceramic Coated Implant (Wright Medical Technology, Arlington)

g Rebalance (Biomet, Bridgend, UK)

h Trabecular Metal Total Ankle (Zimmer inc, Warsaw, Indiana, USA)

Table 2. Data on distribution of diagnoses, sex and age per prosthetic design group

Design group Diagnosis	n (%)	women (%)	Age mean (SD) [range]
All prosthetic designs
Posttraumatic arthritis	443 (36)	53	60 (12) [25–86]
Rheumatoid arthritis	401 (32)	81	56 (14) [18–85]
Osteoarthritis	291 (24)	46	64 (11) [30–88]
Other^a	95 (8)	40	59 (12) [28–76]
All diagnoses	1,230	60	60 (13) [18–88]
Current prosthetic designs
Posttraumatic arthritis	268 (39)	52	62 (12) [30–85]
Rheumatoid arthritis	182 (27)	87	57 (14) [18–83]
Osteoarthritis	155 (23)	45	67 (10) [37–88]
Other^a	78 (11)	37	60 (11) [34–76]
All diagnoses	683	58	62 (12) [18–88]
Early prosthetic designs
Posttraumatic arthritis	175 (32)	54	56 (12) [25–86]
Rheumatoid arthritis	219 (40)	77	56 (14) [21–85]
Osteoarthritis	136 (25)	48	61 (10) [30–84]
Other^a	17 (3)	53	53 (15) [28–74]
All diagnoses	547	62	57 (13) [21–86]

a Including hemophilia, hemochromatosis and psoriatic arthritis

Table 3a. Information on reasons for revision for early prosthetic designs

Reasons for revision	STAR n = 323	BP n = 109	AES n = 115	Total (%)n = 547
Talus and/or tibia
loosening	65	7	16	88 (45)
Technical error	17 ^a	2	19 (10)
Instability	1	3	3	7 (4)
Infection	16	1	4	21 (11)
Intractable pain	10	1	1	12 (6)
PE failure	22	2	2	26 (13)
Painful varus	2	2	2	6 (3)
Painful valgus		1	4	5 (3)
Fracture/dislocation	3	3	2	8 (4)
Other			5	5 (3)
Total number of revisions (%)	136 (42)	22 (20)	39 (34)	197 (36)

Figure 1. Estimated cumulative prosthetic survival for all 1,226 TARs. Number of patients still at risk of experiencing the primary endpoint and prosthetic survival with 95% CI per 5-year period are indicated in the life table

Figure 2. Estimated cumulative prosthetic survival for early and current designs. Number of patients still at risk of experiencing the primary endpoint and prosthetic survival with 95% CI per 5-year period are indicated in the life table

Figure 3. Estimated cumulative prosthetic survival for early designs. Number of patients still at risk of experiencing the primary endpoint and prosthetic survival with 95% CI per 5-year period are indicated in the life table.

Figure 4. Estimated cumulative prosthetic survival for current designs. Number of patients still at risk of experiencing the primary endpoint and prosthetic survival with 95% CI per 5-year period are indicated in the life table.

Table 3b. Information on reasons for revision for current prosthetic designs

Reasons for revision	Hintegra n = 48	Mobility n = 269	CCI n = 151	Rebalance n = 178	TM ankle n = 37	Total (%)n = 683
Talus and/or tibia loosening	4	8	18	5		35 (49)
Technical error	2		1	1		4 (6)
Instability	1	4	1	1		7 (10)
Infection	1	1	1			3 (4)
Intractable pain		6	4	1		11 (15)
PE failure		1				2 (3)
Painful varus		1	2	1		4 (6)
Painful valgus	1	1				2 (3)
Fracture/Lux		1				1 (1)
Other		2	1			2 (3)
Total number of revisions (%)	9 (19)	25 (9)	28 (19)	9 (5)	0 (0)	71 (10)

a The inferior results of the STAR prosthesis is documented in previous reports from the Swedish Ankle Registry (Henricson and Carlsson 2015). The high frequency of “technical errors” may partly be explained by suboptimal instrumentation, limited experience of surgeons, and technical demands (Henricson et al. 2011b).

Henricson A, Carlsson Å. Survival analysis of the single- and double-coated STAR ankle up to 20 years: long-term follow-up of 324 cases from the Swedish Ankle Registry. Foot Ankle Int 2015; 36(10): 1156–60.

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Henricson A, Nilsson J A, Carlsson Å. 10-year survival of total ankle arthroplasties: a report on 780 cases from the Swedish Ankle Register. Acta Orthop 2011b; 82(6): 655–9.

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