Comparison of survival and cost‐effectiveness between unicondylar arthroplasty and total knee arthroplasty in patients with primary osteoarthritis: A follow‐up study of 50,493 knee replacements from the Finnish Arthroplasty Register

Figures & data

Table 1.  Survival of UKAs and TKAs implanted during three time periods. Endpoint defined as any revision. 7‐, 10‐, and 15‐year survival rates were obtained from the Kaplan‐Meier analysis

A	B	C	D	E	F	G	H	I	J	K	L
1980–	UKA	95	12	74	91 (85–97)	61	83(75–91)	40	73 (63–84)	1.2(0.8–1.8)	0.5
1987	TKA	1,995	11	1,525	92 (91–93)	1,208	87 (85–88)	700	78 (76–81)	1.0
1988–	UKA	540	8.4	398	81 (77–84)	244	72 (68–77)	15	‐	2.1 (1.8–2.5)	< 0.001
1995	TKA	12,480	8.7	9,810	92 (92–93)	5,539	89 (88–89)	381	78 (76–80)	1.0
1996–	UKA	1251	2.1	23	82 (77–87)	0	‐	0	‐	3.0 (2.4–3.8)	< 0.001
2003	TKA	34,132	3.3	1,201	95 (95–96)	0	‐	0	‐	1.0
A Time cohort							H Percent 10–year survival (95% CI
B Implant concept							I At risk at 15 years
C Number of operations (knees)							J % 15–year survival (95% CI)
D Mean follow‐up (years)							K Adjusted risk ratio from the Cox regression analysis
E At risk at 7 years							(UKAs compared to TKAs; adjustment made for age
F Percent 7–year survival (95% CI)							and sex) for revision (95% CI)
G At risk at 10 years							L P‐value

Figure 1. Average length of hospital stay after UKA and TKA in Finland, 1988–2003.

Figure 2. Cox‐adjusted survival curves for 48,607 TKAs and 1,886 UKAs. The endpoint was defined as revision for any reason. Adjustment was made for age and sex.

Figure 3. Survival curves for Miller‐Galante II / Nexgen TKAs and Miller‐Galante II UKAs from the Cox regression model (adjusted for age and sex). The endpoint was defined as revision for any reason.

Figure 4. Survival curves for Duracon TKAs and Duracon UKAs from the Cox regression model (adjusted for age and sex). The endpoint was defined as revision for any reason.

Figure 5. Survival curves for AGC V2 TKAs and Oxford menisceal bearing UKAs from the Cox regression model (adjusted for age and sex). The endpoint was defined as revision for any reason.

Table 2.  Survival of the three implant pairs. The endpoint was defined as any revision. 7–, 10–, and 15–year survival rates were obtained from the Kaplan‐Meier analysis

B	C	D	E	F	G	H	I	J	K	L
Miller‐Galante II UKA 330		7.1	188	86 (82–90)	82	79 (73–84)	0	2.7	(1.9–3.8)	<0.001
Miller‐Galante II / Nexgen TKA	4,427	3.9	1,035	96 (95–96)	379	93 (91–95)	0	1,0
Duracon UKA	140	6.5	73	81 (75–88)	24	79 (70–87)	0	4.3	(2.9–6.3)	<0.001
Duracon TKA	15,823	4.1	1,326	96 (95–96)	854	94 (93–95)	0	1.0
Oxford meniscal bearing	1,113	2.0	62	90 (86–95)	45	80 (72–89)	0	1.9	(1.4–2.5)	<0.001
AGC V2	10,721	4.7	2,908	95 (94–95)	976	91 (90–93)	66	86(83–89) 1.0
For Legends see Table 1