Native and prosthetic septic arthritis in a university hospital in Saudi Arabia: A retrospective study

Table 1 Distribution of gender, joint type, affected joint, imaging, and Echo results

Variables	Attributes	N	%
Gender	Male	26	50.0
	Female	26	50.0
Joint type	Native	33	63.5
	Prosthetic	19	36.5
Affected joints	Knee	42	80.8
	Hip	4	7.7
	Shoulder	2	3.8
	Ankle	2	3.8
	Elbow	1	1.9
	Sterno-clavicular	1	1.9
Imaging	Joint effusion	18	34.6
	Joint effusion and osteomyelitis	3	5.8
	Joint swelling	1	1.9
	Loosening of prosthesis	1	1.9
	Not done	8	15.4
	Prosthetic joint fluency	1	1.9
	Soft tissue swelling	18	34.6
	Soft tissue swelling and osteomyelitis	2	3.8
Echo	Joint effusion	2	3.8
	Loosening of prosthesis	1	1.9
	No vegetations	20	38.5
	Not done	22	42.3
	Soft tissue swelling	4	7.7
	Vegetations	3	5.8

Table 2 Organisms in native and prosthetic joints

Organism	N	%
Native joints
Bacteroides stercoris	1	3.0
Coagulase-negative staphylococcus	1	3.0
Enterobacter cloacae	1	3.0
Enterococcus faecalis	1	3.0
ESBL E. coli	3	9.1
Lactobacillus	1	3.0
Leuconostoc	1	3.0
MRSA	8	24.2
Polymicrobial	1	3.0
Pseudomonas aeruginosa	6	18.2
Salmonella	1	3.0
Staphylococcus aureus MSSA	5	15.2
Staphylococcus haemolyticus	1	3.0
Streptococcus uberis	1	3.0
Tuberculosis	1	3.0
Prosthetic joints
Brucella spp	4	21.1
Coagulase-negative staphylococcus	2	10.5
E. coli	2	10.5
Enterococcus faecalis	1	5.3
ESBL klebsiella pneumoniae	1	5.3
MRSA	1	5.3
Pseudomonas aeruginosa	2	10.5
Ralstonia	1	5.3
Staphylococcus aureus MSSA	2	10.5
Staphylococcus epidermidis	1	5.3
Staphylococcus lugdunensis	1	5.3
Tuberculosis	1	5.3

ESBL: Extended-spectrum beta-lactamase; E. coli: Escherichia coli; MRSA: Methicillin-resistant Staphylococcus aureus; MSSA: Methicillin-susceptible Staphylococcus aureus.

Table 3 Comparison of clinical features in native vs prosthetic joints

Clinical feature	Presence	Native		Prosthetic		Odds ratio	P value
		N	%	N	%
Joint pain	Yes	31	93.9	16	45.5	0.344	0.252
	No	2	6.1	3	15.8
Fever	Yes	15	45.5	9	47.4	1.080	0.894
	No	18	54.5	10	52.6
Joint swelling	Yes	33	100	17	98.5	2.941	0.057
	No	0	0	2	10.5
Joint limitation	Yes	30	90.9	17	89.5	0.856	0.866
	No	3	9.1	2	10.5

Table 4 Risk factors/comorbidities

Risk factors/comorbidities present	All cases		Native		Prosthetic		Odds ratio	P value
	N	%	N	%	N	%
Complicated by osteomyelitis	11	21.2	9	27.3	2	10.5	0.314	0.154
Associated with necrotizing fasciitis	7	13.5	2	6.1	5	26.3	0.536	0.039
DM	36	69.2	22	66.7	14	73.7	1.400	0.598
HTN	29	55.8	19	57.6	10	52.6	0.819	0.730
Renal impairment	23	44.2	20	60.6	3	15.8	0.122	0.002
Hemodialysis	15	28.8	14	42.4	1	5.3	0.075	0.004
Heart disease	13	25.0	12	36.4	1	5.3	0.097	0.013
CVD	5	9.6	3	9.1	2	10.5	1.176	0.866
CLD	6	11.5	6	18.2	0	0	0.587	0.048
Malignancy	4	7.7	2	6.1	2	10.5	1.824	0.561
Hematological malignancy	1	1.9	1	3.0	0	0	0.627	0.444
Solid organ malignancy	4	7.7	2	6.1	2	10.5	0.339	0.561
Surgery within 90 days before Dx	5	9.6	2	6.1	2	10.5	2.906	0.252
Osteoarthritis	12	23.1	4	12.1	3	15.8	5.273	0.013
Rheumatoid arthritis	2	3.8	0	0.0	2	10.5	0.340	0.057
Psoriasis	1	1.9	1	3.0	0	0	0.627	0.444
Sickler	1	1.9	1	3.0	0	0	0.627	0.444
Other rheumatological disease	1	1.9	1	3.0	0	0	0.627	0.444
Past septic arthritis	1	1.9	0	0	1	3.0	0.353	0.183
Hx of trauma	9	17.3	4	12.1	5	26.3	2.589	0.181

None of the cases had lung disease or immunosuppressive therapy. DM: Diabetes mellitus; HTN: Hypertension; CVD: Cardiovascular disease; CLD: Chronic liver disease; Dx: Discharge; Hx: History.

Table 5 Distribution of numerical variables

Variables	Mean	Median	SD
BMI	28.63	27.00	6.61
Age	59.31	64.00	17.53
CRP	7535.66	148.50	35267.86
Cell count from aspiration	102998.04	49375.00	139227.01
RBC	90367.48	10583.00	366693.04
Neutrophil	76.21	84.00	27.52
Lymphocyte	4.96	4.00	3.59
Monocyte	10.14	10.00	8.63
Charlson index	2.79	2.00	2.28
Duration of antimicrobials in days	69.86	42.00	100.61

BMI: Body mass index; CRP: C-reactive protein; RBC: Red blood cell.

Table 6 Tuberculosis acid-fast bacilli, tuberculosis polymerase chain reaction, tuberculosis culture, histopathology

Test	Status	N	%
TB AFB	Negative	18	34.6
	Not sent	33	63.5
	Positive	1	1.9
TB PCR	Positive	2	3.8
	Negative	12	23.1
	Not sent	38	73.1
TB culture	Negative	15	28.8
	Not sent	35	67.3
	Positive	2	3.8
Histopathology	Exudate and granulation tissue	1	1.9
	Features of septic joint	2	3.8
	Features of synovitis	1	1.9
	Inflamed granulation tissue	2	3.8
	Inflammatory changes	2	3.8
	Noncaseating granuloma	1	1.9
	Not sent	43	82.7

TB AFB: Tuberculosis acid-fast bacilli; TB PCR: Tuberculosis polymerase chain reaction.

Table 7 Antibiotics used to treat

	Specifics	N	%
Antibiotics	Vancomycin	14	26.9
	Ceftriaxone	6	11.5
	Meropenem	5	9.6
	Cloxacillin	4	7.7
	Ceftazidime	3	5.8
	Antituberculous drugs	2	3.8
	Cefazolin	2	3.8
	Ceftriaxone + rifampin	2	3.8
	Ciprofloxacin	2	3.8
	Imipenem	2	3.8
	Piperacillin tazobactam	2	3.8
	Streptomycin + rifampin + doxycycline	2	3.8
	Ampicillin	1	1.9
	Cefepime	1	1.9
	Gentamicin + rifampin + doxycycline	1	1.9
	Piperacillin tazobactam, vancomycin, clindamycin	1	1.9
	Streptomycin + rifampin	1	1.9
	Teicoplanin	1	1.9

Table 8 Antibiotic prior aspiration, treatment, surgery

Variables	Attributes	N	%
Antibiotics prior aspiration	Yes	30	57.7
	No	22	42.3
Appropriateness of treatment	Appropriate	45	86.5
	Inappropriate	7	13.5
Surgical treatment	Arthrotomy	17	32.7
	Joint preservation	7	13.5
	Arthroscopic irrigation	6	11.5
	Two-stage exchange	6	11.5
	Debridement, antibiotics, and implant retention	4	7.7
	Above knee amputation	1	1.9
	None	11	21.2

Table 9 Correlation between numerical variables

		BMI	AGE	CRP	Cell count	RBC	Neutrophil	Lymphocyte	Monocyte	Creatinine	Charlson
AGE	r value	0.372b
	P value	0.007
CRP	r value	0.025	0.048
	P value	0.861	0.739
Cell count	r value	-0.049	-0.180	0.213
	P value	0.731	0.201	0.137
RBC	r value	-0.042	0.017	-0.331a	0.279a
	P value	0.769	0.906	0.019	0.045
Neutrophil	r value	-0.310	-0.192	0.097	0.082	0.177
	P value	0.140	0.368	0.659	0.702	0.407
Lymphocyte	r value	0.124	0.265	-0.148	-0.349	-0.050	-0.406
	P value	0.565	0.211	0.500	0.094	0.818	0.055
Monocyte	r value	0.379	0.430	-0.543a	-0.311	0.134	-0.816b	0.191
	P value	0.091	0.052	0.013	0.170	0.564	0.000	0.421
Creatinine	r value	-0.100	0.171	0.258	0.240	0.074	0.186	-0.357	-0.170
	P value	0.514	0.260	0.095	0.113	0.631	0.419	0.122	0.461
Charlson	r value	-0.184	-0.041	-0.070	0.331a	0.272	0.268	-0.391	-0.112	0.762b
	P value	0.192	0.771	0.630	0.016	0.051	0.205	0.059	0.629	0.000
Duration of antimicrobials in days	r value	0.109	0.253	0.058	-0.470b	-0.308a	0.121	-0.003	0.298	-0.325a	-0.458b
	P value	0.480	0.098	0.715	0.001	0.042	0.612	0.990	0.202	0.031	0.002

^aP < 0.05, correlation is significant at the 0.05 level (2-tailed).

^bP < 0.05, correlation is significant at the 0.01 level (2-tailed).

BMI: Body mass index; CRP: C-reactive protein; RBC: Red blood cell.

Table 10 Association between variables of interest

Association between	Odds ratio	P value
Joint type and mortality	0.587	0.048
Mortality and appropriateness of treatment	0.848	0.304
Platelet count and mortality	-	0.273
WBC count and mortality	-	0.382

WBC: White blood cell.

Table 11 Relationship between Charlson comorbidity index and mortality

	Charlson comorbidity index
Alive, mean ± SD	2.39 ± 2.02
Dead, mean ± SD	5.83 ± 5.50
P value	0.001