Impact of introducing custom-made articulating spacers: A retrospective cohort study on two protocols for two-stage hip revision

Table 1 General patient characteristics, n (%)

Variable	Group A (n = 39)	Group B (n = 59)	P value
Age, mean (SD)	66 (11.5)	64 (14.6)	0.41
Gender male	25 (64)	28 (47)	0.15
BMI, mean (SD)	28 (5.4)	29 (6.3)	0.32
Diabetes	4 (10)	9 (15)	0.56
ASA score			0.53
1	0 (0)	2 (3)
2	22 (56)	34 (58)
3	17 (44)	22 (37)
4	0 (0)	1 (2)
Infected material			0.45
Primary prosthesis	22 (58)	27 (49)
Revision prosthesis	12 (32)	17 (30)
Internal fixation	4 (11)	7 (13)
Septic arthritis	0 (0)	4 (7)
Post-traumatic indication	10 (56)	15 (42)	0.39
Infection duration, days (SD)	468 (498.3)	411 (407.9)	0.57
Earlier infection related surgery	19 (49)	26 (48)	1.00
Earlier two-stage revision	4 (11)	7 (14)	0.75
Mean months of follow-up (SD)	32 (22.0)	19 (10.3)	< 0.001

BMI: Body mass index; ASA: American Society of Anesthesiologists score.

Table 2 Distribution of causative pathogens, n (%)

Pathogen	Group A (n = 39)	Group B (n = 59)
Polymicrobial	8 (21)	7 (12)
S. Aureus	9 (23)	12 (20)
S. epidermidis	4 (10)	11 (19)
Other CoNS	5 (13)	9 (15)
Cutibacterium acnes	0 (0)	5 (6)
Streptococci	5 (13)	3 (5)
E. Coli	1 (3)	3 (5)
Enterococci	3 (8)	2 (3)
P. Aeruginosa	1 (3)	1 (2)
Other	2 (5)	1 (2)
Culture negative	1 (3)	5 (9)

CoNS: Coagulase negative staphylococci.

Table 3 Treatment details, n (%)

Variables	Group A	Group B	P value
First-stage surgery	n = 39	n = 59
ETO	12 (35)	19 (41)	0.38
Gentamicin beads	6 (15)	0 (0)	0.07
Mean surgical time, min (SD)	149 (49.4)	179 (60.0)	0.02
Mean blood loss, mL (SD)	1128 (581.6)	984 (531.5)	0.32
Interval weightbearing allowance1			< 0.001
0%	32 (82)	21 (36)
10%	7 (18)	29 (49)
50%	0 (0)	9 (15)
Mean length of hospital stay, days (SD)	16 (8.3)	9 (6.5)	< 0.001
Discharge destination			0.048
Home	9 (26)	28 (48)
Extended care facility	26 (74)	30 (52)
Second-stage surgery	n = 35	n = 58
Mean interval duration, days (SD)	213 (266.3)	110 (113.9)	0.01
Mean surgical time, min (SD)	157 (40.1)	165 (54.7)	0.51
Mean blood loss, mL (SD)	1042 (710.1)	886 (586.0)	0.36
Postoperative weightbearing allowance1			0.71
0%	0 (0)	2 (4)
10%	3 (9)	5 (9)
50%	14 (40)	23 (41)
100	18 (51)	26 (46)
Mean length of hospital stay, days (SD)	10 (10.9)	8 (5.6)	0.16
Discharge destination			0.83
Home	20 (61)	31 (57)
Extended care facility	13 (39)	23 (43)

¹Percentage of bodyweight as advised by treating surgeon.

ETO: Extended trochanteric osteotomy.

Table 4 Complications, n (%)

Variables	Group A	Group B	P value
During interval	n = 39	n = 59
Any complication	20 (51)	31 (53)	1.00
Anemia	13 (33)	21 (36)	1.00
AKI	4 (10)	4 (7)	0.71
Delirium	3 (8)	1 (2)	0.30
Decubitus	1 (3)	3 (5)	1.00
Pneumonia	1 (3)	0 (0)	0.40
PJI related death	2 (5)	0 (0)	0.16
Cup loosening	0 (0)	1 (2)	1.00
Spacer dislocation	0 (0)	1 (2)	1.00
After second-stage surgery1	n = 35	n = 58
Any complication	17 (49)	34 (59)	0.39
Anemia	9 (26)	17 (29)	0.81
AKI	1 (3)	5 (9)	0.40
Delirium	1 (3)	1 (2)	1.00
Decubitus	0 (0)	0 (0)
Pneumonia	1 (3)	1 (2)	1.00
PJI related death	3 (9)	0 (0)	0.05
Dislocation	3 (8)	6 (10)	1.00
Mean dislocations per patient (SD)	3.0 (1.0)	2.6 (1.6)	0.67
Aseptic loosening	0 (0)	2 (3)	0.53

¹Until the end of follow-up.

AKI: Acute kidney injury; PJI: Prosthetic joint infection.

Table 5 Reoperations, n (%)

Variable	Group A (n = 39)	Group B (n = 59)	P value
Any reoperation	8 (21)	20 (34)	0.27
Mean surgeries per patient (SD)	2.25 (1.5)	1.85 (1.2)	0.47
During interval
Removal of spacer due to infection	0 (0)	1 (2)	1.00
Debridement	1 (3)	0 (0)	0.40
After second-stage surgery
DAIR	5 (14)	16 (27)	0.20
Two-stage revision	4 (11)	5 (9)	0.72
Revision (non-infectious reasons)	2 (6)	3 (5)	1.00
Plate fixation	1 (3)	1 (2)	1.00

DAIR: Debridement, antibiotics, and implant retention.