Radiostereometric analysis of the double-coated STAR total ankle prosthesis

Figures & data

Table 1.  Demographic data and clinical outcome

Case no. ^a	Gender and age	Diagnosis	Side	Follow-up months	AOFAS pain score	AOFAS total score	Range of motion (degrees)
1	F 77	RA	R	60	40	92	40
2	F 56	RA	L	60	40	77	35
3	F 53	RA	L	60	40	82	25
4	M 83	RA	L	48	40	86	30
5	M 61	RA	R	48	40	74	15
6	M 78	OA	R	48	30	85	40
7	M 73	OA	L	36	40	82	35
7	F 58	OA	L	33	40	84	35
9	F 50	OA	R	36	30	69	30
10	F 61	OA	R	36	40	96	30

^aAll patients were satisfied, except case 9 who was somewhat satisfied

Figure 1. A-p and lateral radiographs of the ankle in case no. 1 at 4 years.

Figure 2. Migration of the tibial component along the x-, y- and z-axes.

Figure 3. Rotation of the tibial component around the x-, y- and z-axes.

Table 2.  The levels of smallest significant migration (mm) and rotation (degrees) at 99% confidence limits in the 3 cardinal axes

Direction of migration and rotation		99% CI
Tibial component (n = 10)
X-migration	Medial-lateral migration	0.1 mm
Y-migration	Proximal migration	0.05 mm
Z-migration	Anteroposterior migration	0.1 mm
X-rotation	Forward-backward rotation	0.2 °
Y-rotation	Axial rotation	0.4 °
Z-rotation	Medial-lateral rotation	0.3 °
Talar component (n = 9)
X-migration	Medial-lateral migration	0.1 mm
Y-migration	Distal migration	0.05 mm
Z-migration	Anteroposterior migration	0.1 mm
X-rotation	Forward-backward rotation	1.5 °
Y-rotation	Axial rotation	0.6 °
Z-rotation	Medial-lateral rotation	1.3 °

Figure 4. Migration of the talar component along the x-, y- and z-axes.

Figure 5. Rotation of the talar component around the x-, y- and z-axes.