Patients undergoing shoulder arthroplasty for failed nonoperative treatment of proximal humerus fracture have low implant survival and low patient-reported outcomes: 837 cases from the Danish Shoulder Arthroplasty Registry

Figures & data

Figure 1. Number of hemiarthroplasties (SHA) and reverse shoulder arthroplasties (RTSA) due to failed nonoperative treatment of proximal humerus fracture registered in the Danish Shoulder Arthroplasty Registry, 2006–2015.

Table 1. Demographics of the study population presented by other type of arthroplasties (Others), stemmed hemiarthroplasty (SHA), and reverse shoulder arthroplasty (RTSA). Values are n (%) unless otherwise specified

	Others	SHA	RTSA	Total ^a
Factor	(n = 65)	(n = 644)	(n = 127)	(n = 837)
Sex
Women	44 (68)	462 (72)	89 (70)	595 (71)
Men	21 (32)	182 (28)	38 (30)	242 (29)
Age
< 65	19 (29)	206 (32)	32 (25)	258 (31)
≥ 65	46 (71)	438 (68)	95 (75)	579 (69)
Age, mean (SD)	69 (11)	70 (11)	71 (9.4)	70 (11)
Indication for surgery
Malunion ^b	33 (51)	134 (21)	55 (43)	222 (27)
Nonunion	23 (35)	470 (73)	61 (48)	555 (67)
Caput necrosis	9 (14)	37 (6)	10 (8)	56 (7)
Missing	–	3 (0)	1 (1)	4 (0)
Period of surgery
2006–2010	25 (38)	393 (61)	14 (11)	432 (52)
2011–2015	40 (62)	251 (39)	113 (89)	404 (48)
Revision	9 (14)	48 (7)	14 (11)	71 (8)
WOOS (completed)	37 (66)	347 (61)	70 (66)	454 (62)
WOOS mean (SD)	38 (26)	47.4 (26)	47.5 (26)	46.6 (26)

^aFor 1 shoulder arthroplasty, there was missing information on

the type of arthroplasty with which the patient was treated.

^bMalunion includes fractures reported together with osteoarthritis.

WOOS: Western Ontario Osteoarthritis of the Shoulder index.

Figure 2. Cumulative survival for all types of arthroplasties, 2006–2015

Table 2. Univariate and multivariate Cox regression model for revision of stemmed hemiarthroplasty (SHA), reverse shoulder arthroplasty (RTSA), sex, age, and period of surgery, (n = 771, revisions = 62)

	Univariate	Multivariate
Factor	HR (CI)	p-value	HR (CI)	p-value
Type of arthroplasty
SHA	1		1
RTSA	2.0 (1.1–3.7)	0.02	1.1 (0.4–2.7)	0.8
Sex
Women	1		1
Men	1.4 (0.8–2.4)	0.2	1.0 (0.5–1.9)	1.0
Age
< 65	1		1
≥ 65	0.7 (0.4–1.2)	0.2	0.7 (0.4–1.2)	0.2
Period of surgery
2006–2010	1		1
2011–2015	1.6 (0.9–2.6)	0.1	1.3 (0.7–2.3)	0.4
SHA + women			1
RTSA + men			3.5 (1.0–12)	0.05

HR (CI): Hazard ratio (95% confidence interval).

SHA: stemmed hemiarthroplasty,

RTSA: reverse shoulder arthroplasty.

Table 3. Multivariate Cox regression model for revision of women (n = 551, revisions = 40) and men (n = 220, revisions = 22) adjusted for age and period of surgery

	Women	Men
Type of arthroplasty	HR (CI)	p-value	HR (CI)	p-value
SHA	1		1
RTSA	1.0. (0.4–2.4)	0.9	6.0 (1.9–19)	0.003

For abbreviations, see Table 2.

Table 4. Reasons for revision for all types of arthroplasties (All), other types of arthroplasties (Others), stemmed hemiarthroplasty (SHA), and reverse shoulder arthroplasty (RTSA). Values are n, (percentage of primary arthroplasties), and percentage of revisions

Reasons for revision	All ^a (n = 837)		Others (n = 65)		SHA (n = 644)		RTSA (n = 127)
Dislocation	23 (2.7)	28	3 (5)	27	12 (1.9)	21	8 (6.3)	62
Loosening	3 (0.4)	4	0 (0)	0	2 (0.3)	4	1 (0.8)	8
Glenoid wear	5 (0.6)	6	0 (0)	0	5 (0.8)	9	0 (0)	0
Infection	9 (1.1)	11	2 (3)	18	6 (0.9)	11	1 (0.8)	8
Fracture	5 (0.6)	6	0 (0)	0	5 (0.8)	9	0 (0)	0
Technical failure	8 (1.0)	10	1 (2)	9	7 (1.1)	12	0 (0)	0
Rotator cuff problems	14 (1.7)	17	2 (3)	18	12 (1.9)	21	0 (0)	0
Other reasons ^b	13 (1.6)	16	2 (3)	18	8 (1.2)	14	3 (2.4)	23
Missing	1 (0.1)	1	1 (2)	9	0 (0)	0	0 (0)	0
Total	81 (9.7)	100	11 (17)	100	57 (8.9)	100	13 (10.2)	100

^a For 1 shoulder arthroplasty, there was missing information on the type of arthroplasty with which the patient was treated.

^b Other reasons includes pain with no other reasons reported.

Figure 4. Distribution of WOOS scores at the 1-year follow-up for all patients.

Table 5. Univariate and multivariate linear regression model for mean difference (MD) in Western Ontario Osteoarthritis of the Shoulder score, type of arthroplasty, sex, age, and period of surgery, (n = 417)

	Univariate	Multivariate
Factor	MD (CI)	p-value	MD (CI)	p-value
Type of arthroplasty
SHA	0		0
RTSA	–0.1 (–6.8 to 6.5)	1.0	–1.9 (–9.2 to 5.5)	0.6
Sex
Women	0		0
Men	1.7 (–3.9 to 7.4)	0.6	3.5 (–2.3 to 9.3)	0.2
Age
< 65	0		0
≥ 65	5.8 (0.5 to 11)	0.03	6.6 (1.1 to 12)	0.02
Period of surgery
2006–2010	0		0
2011–2015	2.1 (–3.0 to 7.1)	0.4	2.4 (–3.1 to 8.0)	0.4

Table 6. Comparison of patients responding or not responding to the Western Ontario Osteoarthritis of the Shoulder index (WOOS). Values are n (%) unless otherwise specified

	Responders	Non-responders
Factor	(n = 454)	(n = 278)	p-value
Type of arthroplasty			0.5
SHA	347 (76)	222 (80)
RTSA	70 (15)	36 (13)
Others	37 (8)	19 (7)
Sex			0.7
Women	329 (72)	198 (71)
Men	125 (28)	80 (29)
Age			0.7
< 65	145 (32)	85 (31)
≥ 65	309 (68)	193 (69)
Age mean (SD)	69.4 (11.0)	70.1 (11.4)	0.1
Indication for surgery ^a			0.4
Malunion ^b	128 (28)	66 (24)
Nonunion	293 (65)	191 (69)
Caput necrosis	32 (7)	20 (7)
Period of surgery			0.2
2006–2008	146 (32)	76 (27)
2009–2011	139 (31)	100 (36)
2012–2015	169 (37)	102 (37)

^a Responders, n = 453. Non-responders, n = 277, stemmed hemi-arthroplasty (SHA), and reverse shoulder arthroplasty (RTSA).

^b Malunion includes fractures reported together with osteoarthritis.