Poor prosthesis survival and function after component exchange of total ankle prostheses

Figures & data

Table 1. Primary diagnoses of patients with revision TAR and status after revision TAR including 95% CI for risk of new failure

Diagnosis	n	Status after revision TAR (n)
		In place	New failure (CI)
Osteoarthritis	14	10	4 (1–8)
Rheumatoid arthritis	16	7	9 (5–13)
Posttraumatic arthritis	38	28	10 (5–16)
Other	1	0	1
Total	69	45	24 (16–32)

Table 2. Types of primary prostheses in 69 patients who underwent revision TAR, and time from primary surgery to revision

Type of primary prosthesis	n	Median time in months (range) from primary surgery to revision
AES	4	36 (4–80)
BP	8	25 (4–89)
CCI	10	22 (8–42)
Hintegra	5	15 (0–67)
Mobility	1	48
Rebalance	2	18 (17–19)
STAR	39	22 (0–101)
Total	69	22 (0–101)

Table 3. Causes of failure of primary TAR and status after revision TAR ^a

Diagnosis	n	Status after revision TAR (n)
		In place	New failure (CI)
Loosening, tibia	22	15	7
Loosening, talus	6	5	1
Loosening, tibia and talus	9	7	2
Technical failure	17	10	7
Infection	2^b	2	0
Other	13	6	7
Total	69	45	24
Total aseptic loosening	37	27	10 (CI 5–16)
Total technical and other failure	30	16	14 (CI 8–20)

^a 95% CI for risk of new failure was calculated for groups “aseptic loosening” and “technical and other failure”.

^b Two patients with deep infection underwent a 2-stage procedure

with a spacer of antibiotic cement for 8 weeks and further implantation of new TARs, which are still in place.

Figure 1. Flow chart of the 69 patients with revision TAR. ^a 4 patients with revision TAR <12 months ago not included in PROM evaluation.

Figure 2. Survival of revision TARs, showing a 5-year survival rate of 76% and a 10-year survival rate of 55%. For comparison, the survival of primary TARs in the Swedish Ankle Registry (Henricson et al. 2011b), modified by excluding meniscus exchange, showed a 5-year survival rate of 84% and a 10-year survival rate of 74%.

Table 4. Mean functional scores and patient satisfaction after revision TAR

Score^a	Mean (95% CI)^b	Patient 1^c	Patient 2^d
SEFAS (not available)	22 (19–26)	26	24
EQ-5D	0.6 (0.5–0.7)	0.7	0.8
EQ-VAS (82)	64 (58–74)	90	80
Very satisfied	(see Table 5)	Yes	Yes
SF-36 physical function (78)	52 (43–61)	65	50
SF-36 bodily pain (66)	50 (40–61)	62	42
SF-36 physical	37 (33–41)	37	36
SF-36 mental	49 (43–55)	65	41

^a Age-specific mean in Swedish population in parenthesis

^b 29 patients with first revision TAR in situ for > 1 year.

^c Patient 1 with re-revision TAR.

^d Patient 2 with re-re-revision TAR.

Table 5. Degree of patient satisfaction after revision TAR related to primary diagnosis. Values are number of patients within each group

Diagnosis	n	S	N	D
Osteoarthritis	5	4	0	1
Rheumatoid arthritis	4	3	1	0
Posttraumatic arthritis	20	8	4	8
Total	29	15	5	9

S: Very satisfied or satisfied

N: Neither satisfied nor dissatisfied

D: Dissatisfied or very dissatisfied

Henricson A, Nilsson JA, Carlsson A. 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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