Total hip replacement after femoral neck fractures in elderly patients : Results of 8,577 fractures reported to the Norwegian Arthroplasty Register

Figures & data

Table 1.  Descriptive statistics for the different patient groups

	n	Mean age (range)	[SD]	Women	Earlier operation
Acute fracture	487	76 (60–97)	[7.7]	82%	0%
Sequelae after fracture	8,090	77 (60–100)	[7.3]	81%	100%
OA	55,109	74 (60–97)	[6.5]	71%	1.7%

Figure 1. Adjusted prosthesis survival curves for the different diagnoses

Figure 2. Time-dependent relative risks (RRs) of revision, with 95% confidence intervals, for prostheses in patients with sequelae after femoral neck fractures compared to prostheses in OA patients. The horizontal red dotted line indicates overall RR. The horizontal black line represents the risk of revision in OA patients. The x-axis is logarithmic. The curves show an increased overall RR of revision due to any cause during the first year (A), an increased RR of revision due to dislocation during the first 2 weeks (B), and an increased RR of revision due to infection during the first year (C)

Table 2.  Number of revisions after diagnosis. Several reasons may exist for each revision. The table also shows relative risk (RR) of revision for the different diagnoses. RR was adjusted for differences in sex, age, and type of cement in a Cox model

Reason for revision	OA (n 55,109)		Acute fracture (n 487)			Sequelae after fracture (n 8,090)
	n	Reference	n	RR (95%CI)	P-value	n	RR (95%CI)	P-value
All revisions	2,904	1	16	1.6 (1.0–2.6)	0.05	375	1.3 (1.2–1.5)	< 0.001
Loose acetabular component	993	1	0			68	0.72 (0.57–0.93)	0.01
Loose femoral component	1,765	1	7	1.6 (0.76–3.4)	0.2	187	1.2 (1.1–1.5)	0.005
Dislocation	412	1	5	2.0 (0.81–4.7)	0.1	112	2.0 (1.6–2.4)	< 0.001
Deep infection	315	1	4	2.5 (0.93–6.7)	0.07	46	1.3 (0.97–1.8)	0.08
Periprosthetic fracture	127	1	1	2.4 (0.33–17)	0.4	32	2.2 (1.5–3.3)	< 0.001
Pain	162	1	2	4.0 (0.99–10)	0.05	14	0.93 (0.53–1.6)	0.8

Table 3.  Subanalyses of Charnley prostheses. Number of revisions after diagnosis. Several reasons may exist for each revision. The table also shows relative risk (RR) of revision for the different diagnoses. RR was adjusted for differences in sex, age and type of cement in a COX model

Reason for revision	OA (n 26,790)		Acute fracture (n 221)			Sequelae after fracture (n 4,414)
	n	Reference	n	RR (95%CI)	P-value	n	RR (95%CI)	P-value
All revisions	1,916	1	9	1.6 (0.82–3.0)	0.2	242	1.3 (1.1–1.5)	0.001
Loose acetabular component	203	1	0			36	0.76 (0.53–1.1)	0.1
Loose femoral component	1,395	1	4	1.2 (0.45–3.2)	0.7	142	1.2 (0.98–1.4)	0.08
Dislocation	203	1	5	4.5 (1.9–11)	0.001	69	2.2 (1.6–2.9)	< 0.001
Deep infection	199	1	1	1.1 (0.15–7.7)	1.0	30	1.3 (0.87–1.9)	0.2
Periprosthetic fracture	72	1	1	5.3 (0.73–39)	0.1	15	1.9 (1.0–3.3)	< 0.04
Pain	92	1	0			7	0.82 (0.38–1.8)	0.6