Good function after shoulder arthroplasty

Figures & data

Table 1. Characteristics of non-responders and responders

	Non-responders n = 662	Respondersn = 1203 ^b	p-value ^c
Mean age, years ^a	71	67	< 0.001
Sex, % women	79	74	0.003
5-year prosthesis survival, %	91	93	0.5
Diagnosis
Rheumatoid arthritis	159	253	< 0.001
Fracture sequelae	141	218
Acute fracture	200	248
Osteoarthritis	162	388
Prosthesis type
Hemiprosthesis	493	683	< 0.001
Total prosthesis	25	98
Resurfaced hemiprosthesis	60	209
Reversed total prosthesis	84	213

^a Age at the time of primary operation.

^b n includes all responders with all diagnoses.

^c p-value derived from Chi-square test for sex, diagnosis, and prosthesis type. For age, the Student t-test was used for comparison of groups.

Table 2. Characteristics of patients with the four major diagnoses

	n	Sex, % women	Age at primary operation ^a	Age at follow-up ^a	Follow-up time ^b	Hemi-prosthesis	Total prosthesis n (%) ^c	Resurfaced hemiprosthesis n (%) ^c	Reversed total prosthesis n (%) ^c
Rheumatoid arthritis	253	79	59 (14)	67 (13)	7.6 (4.4)	122 (48)	7	52 (21)	72 (29)
Fracture sequelae	218	79	67 (10)	72 (10)	5.1 (7.7)	142 (65)	11	19 (9)	46 (21)
Acute fracture	248	85	71 (10)	76 (10)	5.3 (3.3)	238 (96)	1	0	9
Osteoarthritis	388	63	69 (9)	74 (9)	4.6 (3.0)	144 (37)	68 (18)	124 (32)	52 (13)

^a mean (SD)

^b Mean time (SD) since primary operation, years.

^d Number and percentage with each prosthesis type in the diagnostic group.

Table 3. Crude mean (SD) preoperative and current OSS and EQ-5D, and mean change in OSS and EQ-5D, according to diagnosis

	Mean (SD) preoperatively	Mean (SD) currently	Mean (SD) change	p-value ^a
OSS total score
Rheumatoid arthritis (n = 253)	16 (8)	31 (12)	15 (12)	< 0.001
Fracture sequela (n = 218)	18 (12)	28 (13)	10 (16)	< 0.001
Acute fracture (n = 248)	40 (15)	30 (12)	–11 (18)	< 0.001
Osteoarthritis (n = 388)	18 (9)	33 (12)	15 (14)	< 0.001
EQ-5D
Rheumatoid arthritis (n = 253)	0.36 (0.20)	0.60 (0.24)	0.25 (0.29)	< 0.001
Fracture sequela (n = 218)	0.45 (0.29)	0.60 (0.25)	0.16 (0.36)	< 0.001
Acute fracture (n = 248)	0.81 (0.29)	0.60 (0.25)	–0.20 (0.34)	< 0.001
Osteoarthritis (n = 388)	0.38 (0.20)	0.65 (0.25)	0.27 (0.30)	< 0.001
EQ-5D VAS
Rheumatoid arthritis (n = 253)	42 (19)	62 (23)	21 (30)	< 0.001
Fracture sequela (n = 218)	52 (27)	62 (27)	10 (34)	< 0.001
Acute fracture (n = 248)	78 (25)	62 (24)	–16 (30)	< 0.001
Osteoarthritis (n = 388)	45 (23)	67 (26)	22 (32)	< 0.001

^a p-value for the difference between preoperative and postoperative values was calculated using paired-samples t-test.

Table 4. Difference in change from preoperative Oxford shoulder score (OSS) to postoperative OSS by diagnosis and prosthesis type, adjusted for sex, age, and revision status

	n ^b	Mean change ^c	Adjusted difference (95% CI) ^d		p-value
Diagnosis ^a
Rheumatoid arthritis	235	16.0	Ref.
Fracture sequelae	191	11.6	–4.4	(–7.0 to –1.8)	0.001
Osteoarthritis	336	15.9	–0.05	(–2.6 to 2.5)	1.0
Prosthesis type
Hemiprosthesis	354	10.9	Ref.
Total prosthesis	78	18.2	7.3	(3.8 to 11)	< 0.001
Resurfaced	177	12.8	1.9	(–0.6 to 4.4)	0.1
Reversed	153	16.1	5.2	(2.6 to 7.8)	< 0.001
Sex
Male	214	12.3	Ref.
Female	548	14.0	2.0	(–0.3 to 4.2)	0.09
Age in years
< 60	220	13.4	Ref.
60–70	250	14.5	0.8	(–1.7 to 3.4)	0.5
> 70	292	12.7	–1.6	(–4.2 to 1.0)	0.2
Undergone revision
No	703	14.1	Ref.
Yes	59	7.0	–7.3	(–11 to –3.7)	< 0.001

^a The patients who were operated due to acute fractures were excluded from the analysis.

^b n = 762 because 97 patients had missing values for at least one of the included variables.

^c For diagnosis and prosthesis type, the mean changes were adjusted for sex, age, and revision status while unadjusted mean change is given for sex, age group, and revision status.

^d The difference in change compared to the reference group, with corresponding p-values, calculated using linear regression analysis with adjustment for the other variables.

Table 5. Preoperative OSS, current OSS, and change in OSS, divided into pain and function scores, for patients with the four major diagnoses

		Mean (SD)	Mean (SD)	Mean	Adjusted	p-value
Diagnosis ^a	preoperatively	currently	change ^b	difference ^c
OSS pain
Rheumatoid arthritis	3.6 (2.2)	9.8 (4.5)	6.7	Ref.
Fracture sequelae	4.6 (4.1)	8.4 (4.3)	4.4	–2.4	< 0.001
Acute fracture	13 (5.2)	9.6 (4.1)	–3.7	–	–
Osteoarthritis	3.6 (2.3)	9.5 (4.7)	6.4	–0.3	0.5
OSS function
Rheumatoid arthritis	12 (6)	20 (8)	9.2	Ref.
Fracture sequelae	13 (9)	19 (9)	7.0	–2.2	0.02
Acute fracture	27 (10)	20 (9)	–7.0	–	–
Osteoarthritis	14 (7)	23 (8)	9.5	0.4	0.7

^a The patients who were operated due to acute fractures were excluded from the regression analysis.

^b For RA, FS, and OA, the mean changes were adjusted for sex, age, and revision status while unadjusted mean change is given for acute fractures since they were not included in the analyses.

^c The difference in change compared to the reference group, with corresponding p-values, calculated using linear regression analysis with adjustment for age, sex, and prosthesis type.

Figure. Distribution of preoperative OSS (A), current OSS (B), and change in OSS (C) in patients with rheumatoid arthritis (RA), fracture sequelae (FS), acute fracture (AF), and osteoarthritis (OA). The number of patients with a preoperative OSS of 48 (the best possible score) in the AF group was 140 and the number with a current OSS of 48 in the OA group was 40.