Posterior approach and uncemented stems increases the risk of reoperation after hemiarthroplasties in elderly hip fracture patients

Figures & data

Survival analysis of bipolar and unipolar implants in the age group 60–74 years.

Table 1. Crude reoperation rates

	No reoperation		Reoperation		Total
	n	%	n	%	n
Sex
Men	8,793	96.1	353	3.9	9,146
Woman	23,248	96.6	811	3.4	24,059
Age group
< 75 years	3,085	94.7	171	5.3	3,256
75–85 years	15,545	96.4	576	3.6	16,121
> 85 years	13,411	97.0	417	3.0	13,828
Dementia
No	18,978	96.6	668	3.4	19,646
Uncertain	2,895	96.1	117	3.9	3,012
Yes	6,449	96.5	233	3.5	6,682
Missing data	3,719	96.2	146	3.8	3,865
Approach
Posterior	11,522	96.0	477	4.0	11,999
Direct lateral	20,519	96.8	687	3.2	21,206
Stem type
Uncemented	3,037	94.5	178	5.5	3,215
Cemented	29,004	96.7	986	3.3	29,990
Head type
Bipolar	22,138	96.2	878	3.8	23,016
Unipolar	9,903	97.2	286	2.8	10,189
Hospital volume (operations/year)
≤ 100	18,685	96.6	648	3.4	19,333
> 100	13,356	96.3	516	3.7	13,872

Table 2. Risk factors for reoperation of any kind for different age groups. Cox regression analysis with hazard ratios (HR) and 95% confidence intervals (CI). Head design has been omitted for ages 60–74 years due to lack of proportionality

	Age > 85 years(n = 13,828)		Age 75–85 years(n = 16,121)		Age < 75 years(n = 3,256)
	HR (95% CI)	p-value	HR (95% CI)	p-value	HR (95% CI)	p-value
Sex
Men	1.3 (1.0–1.6)	0.02	1.3 (1.1–1.6)	0.001	0.9 (0.6–1.2)	0.4
Women ^a	1		1		1
Stem type
Uncemented	2.2 (1.7–2.8)	< 0.001	1.6 (1.2–2.0)	< 0.001	1.4 (0.9–2.2)	0.09
Cemented ^a	1		1		1
Head type
Bipolar	1.4 (1.2–1.8)	0.002	1.2 (1.0–1.4)	0.1
Unipolar ^a	1		1
Surgical approach
Posterior	1.4 (1.2–1.8)	0.001	1.2 (1.0–1.4)	0.1	1.1 (0.9–1.6)	0.4
Direct lateral ^a, b	1		1		1
Hospital volume (operations/year)
≤ 100	0.8 (0.7–1.1)	0.06	0.9 (0.7–1.0)	0.8	0.8 (0.6–1.0)	0.08
> 100 ^a	1		1		1

^a Reference

^b The Hardinge and Gammer approaches together

Table 3. Risk factors for reoperation due to specific complications for all ages. Cox regression analysis with hazard ratios (HR) and 95% confidence intervals (CI)

	Dislocation (n = 443)		Infection (n = 424)		Fracture (n = 154)		Erosion and other (n = 130)
	HR (95% CI)	p-value	HR (95% CI)	p-value	HR (95% CI)	p-value	HR (95% CI)	p-value
Sex
Men	1.1 (0.9–1.3)	0.5	1.1 (0.9–1.4)	0.2	2.4 (1.7–3.3)	< 0.001	1.2 (0.8–1.7)	0.4
Women ^a	1		1		1		1
Age group
< 75 years	1.4 (1.1–2.0)	0.02	1.5 (1.1–2.0)	0.006	0.9 (0.5–1.5)	0.6	3.6 (2.1–6.2)	< 0.001
75–85 years	1.1 (0.9–1.4)	0.2	0.9 (0.7–1.1)	0.2	0.9 (0.7–1.3)	0.7	2.1 (1.3–3.2)	0.01
> 85 years ^a	1		1		1		1
Stem type
Uncemented	1.1 (0.8–1.6)	0.5	1.5 (1.2–2.0)	0.003	3.6 (2.4–5.3)	< 0.001	3.1 (2.0–4.7)	< 0.001
Cemented ^a	1		1		1		1
Head type
Bipolar	1.0 (0.8–1.3)	0.8	1.6 (1.3–2.1)	< 0.001	2.1 (1.3–3.2)	0.001	0.7 (0.5–1.1)	0.1
Unipolar ^a	1		1		1		1
Surgical approach
Posterior	2.2 (1.8–2.6)	< 0.001	0.8 (0.7–1.0)	0.05	1.5 (1.1–2.0)	0.03	0.5 (0.4–0.8)	0.003
Direct lateral ^a, b	1		1		1		1
Hospital volume (operations/year)
≤ 100	1.1 (0.9–1.4)	0.2	0.9 (0.8–1.1)	0.4	0.2 (0.2–0.3)	< 0.001	1.0 (0.7–1.4)	0.8
> 100 ^a	1		1		1		1

^a Reference

^b The Hardinge and Gammer approaches together

Table 4. Risk factors for reoperation due to specific complications for patients in 3 age groups (A–C). Cox regression analysis with hazard ratios (HR) and 95% confidence intervals (CI). Head design has been omitted for ages 60–74 years due to lack of proportionality

	Dislocation		Infection		Fracture
	HR (95% CI)	p-value	HR (95% CI)	p-value	HR (95% CI)	p-value
A. Patients > 85 years	(n = 157)		(n = 169)		(n = 60)
Sex
Men	1.1 (0.8–1.6)	0.6	1.3 (1.0–1.9)	0.1	1.8 (1.1–3.1)	0.03
Women ^a	1		1		1
Stem type
Uncemented	2.3 (1.3–3.2)	0.002	1.6 (1.1–2.5)	0.02	3.9 (2.1–7.3)	< 0.001
Cemented ^a	1		1		1
Head type
Bipolar	1.0 (0.7–1.4)	1.0	1.8 (1.2–2.6)	0.003	1.7 (0.9–3.3)	0.09
Unipolar ^b	1		1		1
Surgical approach
Posterior	2.5 (1.8–3.4)	< 0.001	1.0 (0.7–1.3)	0.8	2.0 (1.2–3.3)	0.01
Direct lateral ^a, b	1		1		1
Hospital volume (operations/year)
≤ 100	1.2 (0.9–1.7)	0.3	0.9 (0.7–1.3)	0.6	0.2 (0.1–0.4)	< 0.001
> 100 ^a	1		1		1
B. Patients 75–85 years	(n = 228)		(n = 187)		(n = 78)
Sex
Men	1.2 (0.9–1.5)	0.3	1.1 (0.8–1.5)	0.6	3.0 (1.9–4.7)	< 0.001
Women ^a	1		1		1
Stem type
Uncemented	0.7 (0.4–1.2)	0.2	1.3 (0.9–2.0)	0.2	3.6 (2.1–6.1)	< 0.001
Cemented ^a	1		1		1
Head type
Bipolar	1.0 (0.8–1.3)	1.0	1.6 (1.1–2.3)	0.01	2.3 (1.2–4.5)	0.01
Unipolar ^a	1		1		1
Surgical approach
Posterior	2.0 (1.5–2.6)	< 0.001	0.8 (0.6–1.0)	0.07	1.1 (0.7–1.8)	0.6
Direct lateral ^a, b	1		1		1
Hospital volume (operations/year)
≤ 100	1.2 (0.9–1.6)	0.1	0.9 (0.7–1.2)	0.5	0.3 (0.2–0.4)	< 0.001
> 100	1		1		1
C. Patients 60–74 years	(n = 58)		(n = 68)		(n = 16)
Sex
Men	0.8 (0.4–1.4)	0.3	0.9 (0.5–1.5)	0.7	2.0 (0.8–5.5)	0.2
Women ^a	1		1		1
Stem type
Uncemented	0.8 (0.3–2.0)	0.7	1.8 (1.0–3.4)	0.05	2.9 (0.8–10.6)	0.1
Cemented ^a	1		1		1
Surgical approach
Posterior	2.4 (1.4–4.0)	0.001	0.7 (0.4–1.1)	0.1	1.6 (0.6–4.3)	0.4
Direct lateral ^a, b	1		1		1
Hospital volume (operations/year)
≤ 100	0.7 (0.4–1.2)	0.2	0.9 (0.6–1.5)	0.6	0.2 (0.1–0.6)	0.005
> 100 ^a	1		1		1

^a Reference

^b The Hardinge and Gammer approaches together