The risk of revision in total knee arthroplasty is not affected by previous high tibial osteotomy

Figures & data

Figure 1. Example of extra-articular malalignment after high tibial osteotomy (HTO) with opening wedge technique. The red line on the left radiograph (a) indicates the mechanical axis lateral to the knee joint. The radiograph to the right (b) indicates the extra-articular angulation of the tibia in the osteotomy area.

Figure 2. Example of intra-articular malalignment after high tibial osteotomy (WTO) with closing wedge technique. The solid red line indicates that the tibial plateau has been elevated medially and is not perpendicular to the tibial axis.

Figure 3. 31,077 primary total knee arthroplasties and 1,399 total knee arthroplasties after previous high tibial osteotomy (HTO) were selected for inclusion in the study. Total knee arthroplasties with a patellar component, uncemented total knee arthroplasty, knees treated with unicompartmental or revision implants, and uncommon implant brands were excluded.

Table 1. Patient and procedure characteristics for TKA with and without previous HTO from 1994 to 2013 with the diagnosis osteoarthritis

	TKA alone	TKA after HTO	p-value
No. of primary procedures	31,077	1,399
No. of revisions	1,387	83	0.01
Male sex, %	32.4	48.8	0.001
Age, years ^a	71 (28–101)	69 (41–93)	0.001
Surgery time, min ^a	90 (7–950)	103 (40–900)	0.001
Stemmed implants, %	1	1.6
No. of procedures in time period:			0.001
1994–1999	2,648	266
2000–2005	8,540	524
2006–2013	19,889	609

^a Median (range).

Table 3. Reasons for revision

	TKA alone n (%)	TKA after HTO n (%)	p-value
Infection	289 (21)	10 (12)	0.1
Loosening/PE wear	395 (28)	29 (35)	0.2
Dislocation	275 (20)	19 (23)	0.5
Pain only	90 (6)	9 (11)	0.2
Other/progression of OA	338 (25)	16 (19)	0.3
Total	1387 (100)	83 (100)

Table 2. Cox regression analysis adjusted for age, sex, duration of surgery, and time period of surgery

	No. of TKAs	No. of revisions	10-year survival^a (95% CI)	Adjusted RR^b (95% CI)	p-value
TKA alone	31,077	1,387	93.8 (93.4–94.2)	1 (ref)
TKA after HTO	1,399	83	92.6 (91.0–94.2)	0.97 (0.77–1.21)	0.8

^a Kaplan-Meier estimated cumulative survival at 10 years, %.

^b Relative risk

Figure 4. 4,853 high tibial osteotomies with the procedure code NGK59 registered in the Norwegian Patient Register (NPR) from 1999 to 2013, showing the distribution of men and women. The NOMESCO (Nordic Social Statistical Committee) classification of surgical procedures was used.

Figure 5. Cox-adjusted survival curves for TKA with or without previous HTO, with revision for any reason as endpoint. The results of Cox regression analysis were adjusted for age, sex, duration of surgery, and time period.

Figure 6. Adjusted Cox regression curves comparing 3 time periods for TKA with or without previous HTO, with revision for any reason as the endpoint. The results of Cox regression analysis were adjusted for age, sex, and duration of surgery.