The significance of the vitamin D metabolism in the development of periprosthetic infections after THA and TKA: a prospective matched-pair analysis of 240 patients

Figures & data

Figure 1 Schematic representation of vitamin D metabolism and its influence on infections.

Table 1 Comparison of the examination groups (SG, CG I [primary arthroplasty], CG II [aseptic revision]) with respect to the number of subjects, median age [min–max], number [absolute, %] of male subjects, THA or TKA and known osteoporosis

	SG	CG I	CG II
Number of subjects	80	80	80
Median age in years (min–max)	74 (35–92)	71 (39–87)	70 (40–85)
Number of male patients (%)	39 (48.8)	39 (48.8)	35 (43.8)
Number of THA (%)	38 (47.5)	38 (47.5)	43 (53.8)
Number of TKA (%)	42 (52.5)	42 (52.5)	37 (46.3)
Number of known osteoporosis (%)	21 (26.3)	15 (18.8)	19 (23.8)

Abbreviations: CG, control group; max, maximum; min, minimum; SG, study group; THA, total hip arthroplasty; TKA, total knee arthroplasty.

Table 2 Comparison of the examination groups (SG, CG I [primary arthroplasty], CG II [aseptic revision]) with regard to laboratory evaluations including inflammatory, osteological and protein parameters and questionnaire evaluation

	SG	CG I	P-value (SG vs CG I)	CG II	P-value (SG vs CG II)
Laboratory test
Hemoglobin in mmol/L (7.2–10.0)	6.3±1.30	8.7±0.72	<0.001	8.3±0.80	<0.001
Leukocytes in exp9/L (3.5–9.8)	7.80±2.50	7.25±1.25	0.293	7.10±1.61	0.969
C-reactive protein in mg/L (<5)	61.5±76.0	2.5±3.8	<0.001	6.2±11.8	<0.001
Calcium in mmol/L (2.19–2.54)	2.20±0.15	2.35±0.10	<0.001	2.37±0.10	<0.001
Patients with lowered Ca values in %	39.0%	4.0%	<0.001	6.3%	<0.001
Alkaline phosphatase in µg/L (5.7–32.9)	1.59±0.61	1.38±0.33	0.027	1.37±0.36	<0.001
25 OH vitamin D3 in ng/mL (20.0–47.9)	17.9±8.93	16.8±6.90	0.846	19.7±7.90	0.771
Patients with 25 OH vitamin D3 deficiency <20 ng/mL in %	46.0%	57.0%	0.342	47.5%	0.654
Patients with 25 OH vitamin D3 insufficiency: 20–29 ng/mL in %	37.7%	31.0%	0.492	35.0%	0.720
Patients with normal 25 OH vitamin D3 >30 ng/mL in %	16.3%	12.0%	0.765	17.5%	0.832
Parathyroid hormone in pmol/L (1.6–6.9)	3.85±2.3	4.72±2.5	0.166	4.08±1.8	0.004
Albumin in g/L (35–52)	36.0±6.1	45.0±2.6	<0.001	43.9±2.9	<0.001
Patients with lowered albumin values in %	42.0%	1.0%	<0.001	2.5%	<0.001
Serum protein in g/L (63–83)	68.2±7.2	70.1±3.7	0.116	71.6±3.8	0.004
Patients with lowered serum protein values in %	30.0%	5.0%	<0.001	2.5%	<0.001
Creatinine in µmol/L (45–84)	76.0±25.5	77.0±29.7	0.904	73.0±15.5	0.143
Alanine aminotransferase in µkat/L (0.17–0.58)	0.33±0.13	0.35±0.17	0.007	0.30±0.14	0.675
Questionnaire
Taking osteoporosis medication in %	26.3% (21/80)	17.5% (14/80)	0.041	11.3% (9/80)	<0.001
Taking cortisone preparations in %	3.8% (3/80)	5.0% (4/80)	0.797	2.5% (2/80)	0.566
Taking psychotropic drugs in %	2.5% (2/80)	1.3% (1/80)	0.630	2.5% (2/80)
Time spending outdoors in hours	1.0±0.89	2.0±1.30	0.007	2.0±1.25	0.03
Time in motion (shopping, housework) in hours per day	1.0±1.15	4.0±2.91	<0.001	5.0±2.43	<0.001
Sports activities in %	13.8% (11/80)	43.8% (35/80)	0.089	32.5% (26/80)	0.139
Sports activities in hours per week	3.5±2.24	3.0±2.79	0.876	3.0±1.94	0.921
Osteoporotic fractures in history in %	23.8% (19/80)	5.0% (4/80)	<0.001	12.5% (10/80)	0.004
Feeling of having lost size in %	15.0% (12/80)	40.0% (32/80)	0.014	46.3% (37/80)	<0.001

Notes: Pathological values are highlighted in italics. Statistically significant values are highlighted in bold. The values are expressed as median (±mean deviation) or as percentage (share/total). The standard values or the physiological range are given in brackets.

Abbreviations: CG, control group; max, maximum; min, minimum; SG, study group.

Table 3 Comparison of the examination groups with differentiation between acute and chronic infections according to laboratory evaluations including inflammatory, osteological and protein parameters

	Acute infection	Chronic infection	P-value
Number of subjects (excluded antiosteoporotic-treated patients)	25.4% (15/59)	74.6% (44/59)
Hemoglobin in mmol/L (7.2–10.0)	5.3±1.53	6.5±1.34	0.015
Leukocytes in exp9/L (3.5–9.8)	11.4±4.3	7.6±1.4	<0.001
C-reactive protein in mg/L (<5)	176.3±64	27.3±54	<0.001
Calcium in mmol/L (2.19–2.54)	2.13±0.18	2.23±0.14	0.010
Patients with lowered Ca values in %	73.3% (11/15)	38.6% (17/44)	<0.001
Alkaline phosphatase in µg/L (5.7–32.9)	1.59±0.53	1.59±0.65	0.880
25 OH vitamin D3 in ng/mL (20.0–47.9)	8.3±5.98	21.6±8.40	0.002
Patients with 25 OH vitamin D3 deficiency <20 ng/mL in %	86.7% (13/15)	45.5% (20/44)	<0.001
Patients with 25 OH vitamin D3 insufficiency: 20–29 ng/mL in %	13.3% (2/15)	50% (22/44)	<0.001
Patients with normal 25 OH vitamin D3 >30 ng/mL in %	0	4.5% (2/44)
Parathyroid hormone in pmol/L (1.6–6.9)	3.99±1.3	3.80±2.6	0.541
Albumin in g/L (35–52)	28.0±7.1	37.7±5.5	0.030
Patients with lowered albumin-values in %	80.0% (12/15)	36.4% (16/44)	<0.001
Serum protein in g/L (63–83)	59±7.12	69.3±6.32	0.040
Patients with lowered serum protein values in %	86.7% (13/15)	22.7% (10/44)	<0.001
Creatinine in µmol/L (45–84)	75±36.1	77±21.9	0.390
Alanine aminotransferase in µkat/L (0.17–0.58)	0.33±0.13	0.32±0.13	0.700
Time spending outdoors in hours	1±0.83	1±0.94	0.340

Notes: Pathological values are highlighted in italics. The values are expressed as median (±mean deviation) or as percentage (share/total). The standard values or the physiological range are given in brackets.