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Saudi Journal of Biological Sciences logoLink to Saudi Journal of Biological Sciences
. 2020 Mar 18;27(5):1352–1362. doi: 10.1016/j.sjbs.2020.03.016

The effect of trace elements on BMP-2, BMP-7 and STRO-1+ cells in hip replacement

Xiaodong Fu 1, Weili Wang 1, Xiaomiao Li 1, Yingjian Gao 1, Hao Li 1, Yi Shen 1,⁎
PMCID: PMC7182999  PMID: 32346345

Abstract

To explore the correlation between the trace elements in the proximal femur and BMP-2, BMP-7 and STRO-1+ cells in hip replacement, and analyze the therapeutic effect of prosthesis loosening in clinic. Fifty-one patients undergone the first hip replacement in xxx hospital from August 2016 to August 2019 were selected as the study subjects, including 26 females and 25 males, aged 52–89 years. The bone marrow mesenchymal stem cells (BMSCs) were cultured in vitro for flow cytometry, and the string-1+ in BMSCs was detected and analyzed. After that, the expression of bone morphogenetic protein 2 (BMP-2) and bone morphogenetic protein 7 (BMP-7) in the cells were detected by enzyme-linked immunosorbent assay, the content of trace elements in the supernatant was detected by radioimmunoassay, and the collected data were analyzed statistically. In the analysis of the content of trace elements, it was found that the correlation between trace elements was dependent on the separation area, and all trace elements had no correlation with BMP2. Ca2+, Mg2+ were correlated with the level of BMP7 and Ca2+, VD3 was correlated with the percentage of STOR-1+ cells. Further analysis showed that the correlation between trace elements was dependent on bone mineral density (BMD) area, and there was a positive correlation between vitamin D3 (VD3), parathyroid hormone (PTH), zinc, and BMD in zone 7. To sum up, it is found that trace elements may be related to prosthesis loosening, which provides experimental basis for the treatment of prosthesis loosening later.

Keywords: Hip replacement, Trace elements, Bone morphogenetic protein

1. Introduction

Artificial joint replacement especially hip arthroplasty has become increasingly popular (Berry et al., 2002). Improving the fusion of prosthesis and prolonging the survival rate of prosthesis has become a research hotspot in joint surgery. The current research mainly focuses on prosthesis design, lacking of consideration of the patient's factors. This study discussed the prophylaxis for aseptic loosening of hip prosthesis on the basis of the clinical research of patients.

As a kind of non-hematopoietic stem cells, BMSCs can support hematopoiesis in vitro and in vivo by secreting a variety of growth factors. Because BMSCs are easy to be isolated and cultured and have strong proliferation ability in vitro, they have a broad application prospect in the treatment of bone tissue cells. Stromal cell antigen (STRO-1) is the surface antigen of human bone marrow cells. STRO-1+ stem cells have strong osteogenic differentiation. STRO-1+ bone marrow stem cell cells have strong mesenchymal differentiation, such as fat cells, osteoblasts and chondrocytes (Bidwell et al., 2013). Many factors lead to Stro-1+ cell differences, such as age, gender and other factors (Ganguly et al., 2017, Zheng et al., 2018). Bone morphogenetic proteins (BMPs) belong to the transforming growth factor-β super family and were originally identified to induce ectopic bone growth and cartilage formation as osteoinductive cytokines (Urist, 1965, Wozney et al., 1988). In particular, BMP-2 and BMP-7 have been approved for clinical use in the United States, Europe and Australia (Reddi, 2005). BMP-2 is most extensively studied for its ability to induce bone regeneration in tissue engineering (Carreira et al., 2014). It has been reported that BMP-7 causes the inhibition of the intracellular signaling initiated by TGF-β, through the blockage of Smad 3/4, and diminishes the effects of TGF-β (Pegorier et al., 2010, Lim et al., 2016).

Microelement are essential to maintain normal physiological function and stable internal environment. Microelement also play an important role in bone metabolism. For example, Zinc is an important auxiliary factor of a variety of bone metabolic enzymes like alkaline phosphatase and collagenase, which is closely related with osteogenesis (Qiao et al., 2014, Luo et al., 2014).

From the point of view of the content of trace elements around the prosthesis, the trace elements and bone mineral density (BMD) of 51 patients undergoing hip replacement were investigated, and the relationship between trace elements and BMP-2, BMP-7, STRO-1+ cells was analyzed, thereby providing a reference for the clinical patients after hip replacement to improve the life of the prosthesis.

2. Materials and methods

2.1. Patients

51 cases of patients with the first hip replacement were enrolled from xxx hospital between August 2016 and August 2019. The study was approved by the ethics committee of the hospital. The patients and their families signed the informed consent. The enrolled criteria was list as following: Patients with osteoarthritis and femoral neck fractures; Ages between 50 and 90 years old; With standard pelvic flat and full-length femoral head.

Exclusion criteria: Patients with rheumatoid arthritis and other autoimmune diseases; Patients with non-steroid analgesics, steroid hormones, estrogen replacement therapy, bisphosphonates, and calcium treatment two weeks prior to hip replacement; Complications after hip replacement include infection, leave Implant failure, wound healing and vascular, nerve injury.

2.2. Cell culture

BMSCs were extract from proximal femoral head grooved and discarded bone mass during the hip replacement. Cells were cultured in α-MEM with 20% FBS. And cells were identified by flow cytometric analysis.

2.3. Flow cytometric analysis

Flow cytometric analysis was performed to analyzed the STRO-1+ cells. The specific steps were as follows: (1) recognize and combine different antigens (staining) on cells by antibodies with different fluorescent groups; (2) cell with fluorescence passes through laser one by one; (3) different fluorescent groups have different emission spectra, and the principle of fluorescent dye selection: it must be able to be excited by the laser equipped on the flow cytometer, and the excitation spectrum must be within the proper range that the filter can accept, and the overlap of the fluorescein spectrum should be minimized; (4) the complex fluorescence signal is decomposed by different spectroscopes and filters; (5) the photomultiplier tube (PMT) turns the optical signal into the electrical signal; (6) the analog signal is further transformed into the digital signal that can be processed by the computer through the analog-to-digital converter (ADC).

2.4. Enzyme-linked immunosorbent assay (ELISA)

Human IL-11 ELISA kits (Neobioscience, China) were used in accordance with the manufacturer’s instructions manual to quantify concentrations of the BMP-2 and BMP-7.

2.5. Radio immunofluorescence (RIA)

The level of microelement was measured by radio immunofluorescence assay. According to the principle of antigen antibody reaction, the known antigens or antibodies were labeled with fluorescent groups, and then the fluorescent antibodies (or antigens) were used as probes to check the corresponding antigens (or antibodies) in cells or tissues. The fluorescence microscope can be used to see the cells or tissues where the fluorescence is located, thereby determining the nature and location of antigens or antibodies, and deciding the content by quantitative technology (such as flow cytometry).

2.6. Statistical analyses

SPSS 18.0 software was applied for statistical analysis. Pearson correlation coefficient was used for correlation analysis. r was used to represent the correlation coefficient between variables in the sample, and the size of the correlation. P was used to test whether the two variables have the same correlation in the population from which the sample comes. P < 0.05 indicated that there was correlation between variables.

3. Results

3.1. The concentration of microelement in the culture medium of cell extracted from proximal femur bone

Fig. 1 shows the comparison of the content of trace elements in the body of patients of different genders and ages. To determine the essential role of microelement, we first collected and organized the basic information of enrolled patients. As revealed in Table 1, there are 26 females and 25 males, aged 52–89 years old, with an average age of 68.3. The BMD analysis results were presented in Table 2. Then, we measured the level of five different microelement Ca2+, Mg2+, Zn2+, VD3 and PTH in the culture medium of cell extracted from proximal femur bone. As demonstrated in Table 3, Table 4, Table 5 and Fig. 1, the level of these five microelements were consistent in male and female patients, and the trend not correlate with age.

Fig. 1.

Fig. 1

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Comparison of microelements in patients of different genders and ages.

Table 1.

The baseline information of the patients enrolled in the present study.

Number Gender Age BMP2 (pg/ml) BMP7 (pg/ml) Stro-1 %
1 Female 62 85.577 167.033 6.99
2 Female 83 75.072 167.033 9.54
3 Female 75 85.577 190.020 26.62
4 Male 50 109.213 181.400 8.42
5 Male 71 80.324 198.640 30.27
6 Male 89 101.334 195.766 27.11
7 Male 65 80.324 187.146 8.50
8 Female 75 72.445 227.373 33.00
9 Male 82 88.203 158.413 12.36
10 Male 52 148.607 184.273 22.16
11 Female 65 101.334 169.906 8.85
12 Female 87 80.324 169.906 34.16
13 Female 62 80.324 192.893 12.53
14 Male 55 80.324 175.653 15.52
15 Female 78 75.072 172.780 37.82
16 Female 66 90.829 204.387 19.63
17 Male 54 75.072 181.400 17.29
18 Female 45 75.072 187.146 38.67
19 Female 80 85.577 235.994 23.29
20 Male 89 93.456 190.020 3.59
21 Female 65 101.334 195.766 46.36
22 Female 75 96.082 169.906 21.16
23 Male 82 103.961 184.273 18.89
24 Female 52 80.324 161.286 26.12
25 Male 56 109.084 175.097 23.42
26 Male 67 154.679 140.206 15.71
27 Male 52 66.132 133.228 13.33
28 Male 65 109.084 161.140 6.29
29 Male 63 63.489 129.739 8.65
30 Male 70 81.727 157.651 14.46
31 Female 59 55.251 161.140 7.61
32 Male 56 118.203 175.097 11.09
33 Male 70 99.965 154.162 15.66
34 Female 77 145.560 140.206 29.72
35 Female 56 109.084 133.228 17.75
36 Female 52 81.727 115.782 13.11
37 Female 77 99.965 126.249 11.07
38 Female 87 90.846 178.586 21.44
39 Male 77 99.965 154.162 8.01
40 Male 52 109.084 143.695 11.42
41 Male 52 145.560 199.520 34.83
42 Female 72 136.441 143.695 15.82
43 Female 58 90.846 126.249 8.73
44 Male 63 63.489 112.293 3.07
45 Female 58 191.155 133.228 23.14
46 Female 58 136.441 143.695 21.38
47 Male 86 72.608 185.564 14.88
48 Female 59 127.322 182.075 19.41
49 Male 78 163.798 178.586 20.08
50 Female 79 172.917 230.922 36.99
51 Male 77 118.203 157.651 15.48
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Table 2.

The BMD of the patients enrolled in the present study.

Number Follow-up time Zone1 Zone2 Zone3 Zone4 Zone5 Zone6 Zone7
1 1 week 0.88 1.485 1.425 1.491 1.428 1.334 0.877
3 month 0.872 1.288 1.375 1.267 1.149 1.07 0.679
6 month 0.717 1.349 1.355 1.358 1.401 1.18 0.688
12 month 0.783 1.385 1.378 1.34 1.351 0.98 0.696



2 1 week 0.899 1.19 1.499 1.39 1.531 1.308 0.56
3 month 0.705 1.299 1.597 1.431 1.48 1.249 0.39
6 month 0.613 1.22 1.59 1.487 1.399 1.216 0.439
12 month 0.443 1.266 1.45 1.349 1.348 1.231 0.452



3 1 week 0.666 1.404 1.498 1.497 1.618 1.256 1.028
3 month 0.722 1.326 1.509 1.451 1.672 1.378 1.065
6 month 0.688 1.385 1.575 1.519 1.75 1.406 1.124
12 month 0.849 1.411 1.588 1.535 1.731 1.255 1.17



4 1 week 0.908 1.533 1.471 1.539 1.474 1.377 0.905
3 month 0.900 1.329 1.419 1.308 1.186 1.104 0.701
6 month 0.740 1.392 1.398 1.401 1.446 1.218 0.710
12 month 0.808 1.429 1.422 1.383 1.394 1.011 0.718



5 1 week 0.928 1.228 1.547 1.434 1.580 1.350 0.578
3 month 0.728 1.341 1.648 1.477 1.527 1.289 0.402
6 month 0.633 1.259 1.641 1.535 1.444 1.255 0.453
12 month 0.457 1.307 1.496 1.392 1.391 1.270 0.466



6 1 week 0.687 1.449 1.546 1.545 1.670 1.296 1.061
3 month 0.745 1.368 1.557 1.497 1.726 1.422 1.099
6 month 0.710 1.429 1.625 1.568 1.806 1.451 1.160
12 month 0.876 1.456 1.639 1.584 1.786 1.295 1.207



7 1 week 0.719 1.201 1.629 1.597 1.625 1.144 0.486
3 month 0.795 1.374 1.639 1.621 1.657 1.245 0.446
6 month 0.504 1.179 1.735 1.718 1.679 1.368 0.454
12 month 0.535 1.439 1.838 1.818 1.703 1.57 0.383
8 1 week 0.674 1.420 1.515 1.514 1.636 1.270 1.040
3 month 0.730 1.341 1.526 1.467 1.691 1.394 1.077
6 month 0.696 1.401 1.593 1.536 1.770 1.422 1.137
12 month 0.859 1.427 1.606 1.552 1.751 1.269 1.183
9 1 week 0.705 1.177 1.596 1.565 1.593 1.121 0.476
3 month 0.779 1.347 1.606 1.589 1.624 1.220 0.437
6 month 0.494 1.155 1.700 1.684 1.645 1.341 0.445
12 month 0.524 1.410 1.801 1.782 1.669 1.539 0.375



10 1 week 0.861 1.062 1.072 1.285 1.185 1.072 0.833
3 month 0.669 1.026 1.216 1.319 1.243 1.255 0.584
6 month 0.439 1.055 1.137 1.291 1.222 1.200 0.593
12 month 0.593 1.075 1.179 1.329 1.202 1.178 0.600
11 1 week 0.870 1.141 1.455 1.348 1.479 1.283 0.581
3 month 0.683 1.262 1.551 1.390 1.437 1.213 0.370
6 month 0.595 1.187 1.575 1.450 1.371 1.185 0.488
12 month 0.320 1.228 1.403 1.313 1.305 1.191 0.441
12 1 week 0.831 1.454 1.666 1.619 1.543 1.540 1.686
3 month 0.743 1.440 1.591 1.630 1.579 1.565 1.623
6 month 0.809 1.457 1.581 1.610 1.527 1.641 1.643
12 month 0.767 1.371 1.505 1.680 1.545 1.595 1.700
13 1 week 0.550 1.304 1.389 1.273 1.409 1.366 0.938
3 month 0.633 1.341 1.371 1.267 1.355 1.347 0.856
6 month 0.480 1.310 1.392 1.380 1.377 1.360 0.917
12 month 0.392 1.333 1.391 1.358 1.405 1.417 0.947
14 1 week 0.711 1.569 1.524 1.537 1.961 1.78 0.818
3 month 0.68 1.364 1.56 1.604 2.051 1.841 0.781
6 month 0.654 1.629 1.662 1.608 1.951 1.746 0.784
12 month 0.675 1.555 1.678 1.816 1.975 1.642 0.775
15 1 week 0.720 1.588 1.542 1.555 1.985 1.801 0.828
3 month 0.688 1.380 1.579 1.623 2.076 1.863 0.790
6 month 0.662 1.649 1.682 1.627 1.974 1.767 0.793
12 month 0.683 1.574 1.698 1.838 1.999 1.662 0.784
16 1 week 0.739 1.632 1.585 1.598 2.039 1.851 0.851
3 month 0.707 1.419 1.622 1.668 2.133 1.915 0.812
6 month 0.680 1.694 1.728 1.672 2.029 1.816 0.815
12 month 0.702 1.617 1.745 1.889 2.054 1.708 0.806
17 1 week 0.748 1.651 1.604 1.618 2.064 1.873 0.861
3 month 0.716 1.436 1.642 1.688 2.159 1.938 0.822
6 month 0.688 1.714 1.749 1.692 2.053 1.838 0.825
12 month 0.710 1.637 1.766 1.911 2.079 1.728 0.816
18 1 week 0.875 1.201 1.241 1.33 1.66 1.348 1.018
3 month 0.531 1.291 1.429 1.311 1.598 1.239 1.089
6 month 0.87 1.165 1.437 1.371 1.712 1.388 1.031
12 month 0.722 1.235 1.399 1.465 1.752 1.425 1.029



19 1 week 0.831 1.454 1.666 1.619 1.543 1.540 1.686
3 month 0.743 1.440 1.591 1.630 1.579 1.565 1.623
6 month 0.809 1.457 1.581 1.610 1.527 1.641 1.643
12 month 0.767 1.371 1.505 1.680 1.545 1.595 1.700
20 1 week 0.829 1.262 1.646 1.618 1.644 1.212 0.621
3 month 0.897 1.419 1.654 1.640 1.673 1.303 0.583
6 month 0.635 1.245 1.745 1.729 1.695 1.413 0.590
12 month 0.663 1.478 1.837 1.815 1.711 1.589 0.527
21 1 week 0.661 1.192 1.258 1.244 1.340 1.310 1.067
3 month 0.615 1.185 1.278 1.240 1.402 1.301 1.067
6 month 0.587 1.191 1.365 1.228 1.375 1.262 0.907
12 month 0.552 1.195 1.261 1.237 1.462 1.284 1.003
22 1 week 0.530 1.265 1.418 1.293 1.456 1.448 1.226
3 month 0.594 1.410 1.485 1.360 1.505 1.562 1.244
6 month 0.767 1.318 1.510 1.394 1.526 1.450 1.261
12 month 0.717 1.270 1.584 1.500 1.549 1.461 1.318
23 1 week 0.527 1.109 1.481 1.365 1.670 1.592 1.119
3 month 0.545 1.199 1.511 1.312 1.647 1.601 1.113
6 month 0.542 1.237 1.527 1.420 1.763 1.661 1.137
12 month 0.594 1.301 1.508 1.348 1.721 1.674 1.164
24 1 week 0.984 1.247 1.265 1.266 1.464 1.188 1.262
3 month 0.861 1.265 1.322 1.436 1.522 1.373 1.272
6 month 0.753 1.239 1.482 1.400 1.487 1.319 1.321
12 month 0.753 1.192 1.459 1.487 1.496 1.340 1.360
25 1 week 0.721 1.202 1.629 1.598 1.627 1.147 0.49
3 month 0.797 1.377 1.638 1.622 1.659 1.248 0.448
6 month 0.506 1.183 1.739 1.721 1.683 1.37 0.455
12 month 0.537 1.442 1.841 1.817 1.701 1.566 0.385
26 1 week 0.534 1.124 1.198 1.182 1.289 1.256 0.985
3 month 0.483 1.117 1.22 1.178 1.358 1.245 0.985
6 month 0.452 1.123 1.317 1.164 1.328 1.202 0.808
12 month 0.413 1.128 1.201 1.174 1.424 1.227 0.914
27 1 week 0.389 1.206 1.376 1.237 1.418 1.409 1.162
3 month 0.46 1.367 1.45 1.311 1.472 1.536 1.182
6 month 0.652 1.264 1.478 1.349 1.495 1.411 1.201
12 month 0.597 1.211 1.56 1.467 1.521 1.423 1.264
28 1 week 0.386 1.032 1.445 1.317 1.655 1.569 1.043
3 month 0.405 1.132 1.479 1.258 1.63 1.579 1.037
6 month 0.402 1.174 1.497 1.378 1.759 1.645 1.063
12 month 0.46 1.245 1.476 1.298 1.712 1.66 1.093
29 1 week 0.709 1.567 1.522 1.533 1.955 1.779 0.819
3 month 0.678 1.365 1.556 1.606 2.048 1.838 0.782
6 month 0.656 1.627 1.659 1.6 1.946 1.743 0.785
12 month 0.673 1.553 1.68 1.814 1.977 1.64 0.775



30 1 week 0.768 1.429 1.576 1.771 1.662 1.349 1.049
3 month 0.771 1.436 1.456 1.867 1.728 1.389 1.15
6 month 0.781 1.41 1.567 1.856 1.786 1.396 1.132
12 month 0.765 1.529 1.609 1.887 1.802 1.409 1.12
31 1 week 0.664 1.402 1.494 1.495 1.617 1.252 1.022
3 month 0.723 1.325 1.508 1.449 1.674 1.389 1.063
6 month 0.688 1.381 1.57 1.518 1.748 1.404 1.123
12 month 0.852 1.408 1.587 1.536 1.727 1.257 1.169
32 1 week 0.977 1.65 1.852 2.038 1.628 1.133 1.17
3 month 1.045 1.631 1.866 2.044 1.681 1.084 1.001
6 month 1.08 1.66 2.026 1.997 1.851 1.066 1.115
12 month 0.817 1.621 1.985 1.955 1.802 1.082 1.081
33 1 week 0.893 1.185 1.205 1.207 1.427 1.12 1.202
3 month 0.757 1.205 1.269 1.395 1.491 1.326 1.213
6 month 0.637 1.177 1.447 1.356 1.452 1.265 1.268
12 month 0.637 1.124 1.421 1.452 1.462 1.289 1.311
34 1 week 0.719 1.044 1.338 1.121 1.289 1.31 0.601
3 month 0.795 1.017 1.37 1.139 1.336 1.297 0.692
6 month 0.784 1.185 1.423 1.191 1.35 1.278 0.754
12 month 0.808 1.066 1.369 1.163 1.365 1.301 0.784
35 1 week 0.385 0.938 1.285 1.026 1.106 0.945 1.206
3 month 0.525 0.904 1.353 1.16 1.216 1.073 1.172
6 month 0.531 0.895 1.4 1.252 1.265 1.038 1.165
12 month 0.496 0.869 1.533 1.361 1.276 1.325 1.237
36 1 week 0.839 1.469 1.683 1.635 1.559 1.556 1.703
3 month 0.75 1.455 1.607 1.646 1.595 1.581 1.639
6 month 0.817 1.472 1.597 1.626 1.542 1.658 1.66
12 month 0.775 1.385 1.52 1.697 1.561 1.611 1.717
37 1 week 0.816 1.727 1.702 1.804 1.658 1.321 0.831
3 month 0.784 1.625 1.726 1.716 1.693 1.281 0.896
6 month 0.766 1.628 1.559 1.616 1.54 1.299 0.863
12 month 0.719 1.622 1.577 1.771 1.587 1.279 0.896
38 1 week 0.686 0.966 1.268 1.313 1.542 1.421 0.454
3 month 0.588 0.987 1.374 1.402 1.649 1.542 0.463
6 month 0.496 0.927 1.414 1.262 1.61 1.214 0.413
12 month 0.396 0.893 1.504 1.344 1.636 1.384 0.452
39 1 week 0.542 1.201 1.447 1.351 1.469 1.335 1.044
3 month 0.535 1.169 1.264 1.338 1.257 1.335 1.047
6 month 0.544 1.103 1.404 1.403 1.457 1.323 1.013
12 month 0.563 1.236 1.491 1.463 1.412 1.349 1.002



40 1 week 0.49 1.194 1.323 1.402 1.456 1.319 0.775
3 month 0.439 1.268 1.289 1.367 1.482 1.323 0.563
6 month 0.396 1.271 1.463 1.438 1.509 1.412 0.693
12 month 0.402 1.3 1.546 1.45 1.515 1.466 0.716
41 1 week 0.963 1.971 1.634 1.733 1.515 1.688 0.999
3 month 0.771 1.621 1.611 1.63 1.483 1.42 0.829
6 month 0.852 1.653 1.626 1.734 1.583 1.582 0.868
12 month 0.588 1.578 1.601 1.702 1.517 1.562 0.868
42 1 week 0.873 1.194 1.237 1.319 1.592 1.302 1.007
3 month 0.515 1.281 1.417 1.308 1.588 1.22 1.071
6 month 0.867 1.165 1.42 1.331 1.612 1.328 1.02
12 month 0.702 1.231 1.389 1.412 1.649 1.425 1.013
43 1 week 0.329 1.239 1.499 1.627 1.437 1.217 0.92
3 month 0.537 1.282 1.576 1.558 1.421 1.224 0.914
6 month 0.819 1.298 1.58 1.675 1.473 1.312 0.992
12 month 0.797 1.218 1.467 1.662 1.509 1.348 1.147
44 1 week 0.37 0.987 1.142 1.234 1.233 1.241 0.932
3 month 0.451 1.111 1.174 1.292 1.263 1.07 0.617
6 month 0.656 1.209 1.194 1.238 1.278 1.182 0.784
12 month 0.515 1.227 1.187 1.313 1.412 1.341 0.688
45 1 week 0.879 1.484 1.423 1.488 1.426 1.333 0.874
3 month 0.873 1.287 1.378 1.267 1.156 1.069 0.684
6 month 0.716 1.35 1.356 1.359 1.411 1.2 0.699
12 month 0.784 1.381 1.372 1.342 1.353 0.99 0.699
46 1 week 0.885 1.092 1.102 1.321 1.218 1.102 0.857
3 month 0.688 1.055 1.25 1.356 1.278 1.291 0.601
6 month 0.451 1.085 1.169 1.328 1.257 1.234 0.61
12 month 0.61 1.105 1.212 1.367 1.236 1.211 0.617
47 1 week 0.895 1.173 1.496 1.386 1.521 1.319 0.597
3 month 0.702 1.298 1.595 1.429 1.478 1.247 0.38
6 month 0.612 1.221 1.62 1.491 1.41 1.219 0.502
12 month 0.329 1.263 1.443 1.35 1.342 1.225 0.453
48 1 week 0.519 1.23 1.31 1.201 1.329 1.289 0.885
3 month 0.597 1.265 1.293 1.195 1.278 1.271 0.808
6 month 0.453 1.236 1.313 1.302 1.299 1.283 0.865
12 month 0.37 1.258 1.312 1.281 1.325 1.337 0.893
49 1 week 0.895 1.173 1.496 1.386 1.521 1.319 0.597
3 month 0.702 1.298 1.595 1.429 1.478 1.247 0.38
6 month 0.612 1.221 1.62 1.491 1.41 1.219 0.502
12 month 0.329 1.263 1.443 1.35 1.342 1.225 0.453



50 1 week 0.519 1.23 1.31 1.201 1.329 1.289 0.885
3 month 0.597 1.265 1.293 1.195 1.278 1.271 0.808
6 month 0.453 1.236 1.313 1.302 1.299 1.283 0.865
12 month 0.37 1.258 1.312 1.281 1.325 1.337 0.893
51 1 week 0.57 1.187 1.342 1.434 1.433 1.441 1.132
3 month 0.651 1.311 1.374 1.492 1.463 1.27 0.817
6 month 0.856 1.409 1.394 1.438 1.478 1.382 0.984
12 month 0.715 1.427 1.387 1.513 1.612 1.541 0.888
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Table 3.

The level of microelements in enrolled patients.

Number Gender Age Ca2+ (μM) Mg2+ (μM) Zn (ng/ml) VD3 (nM) PTH (ng/ml)
1 Female 62 2.21 3.23 7.37 28.75 1.90
2 Female 83 2.56 2.87 7.76 34.36 1.95
3 Female 75 2.50 2.87 8.25 36.46 1.99
4 Male 50 2.81 1.54 8.04 35.11 1.96
5 Male 71 2.75 1.18 8.19 36.27 1.99
6 Male 89 2.58 3.34 6.58 25.92 1.65
7 Male 65 2.67 3.16 7.57 29.75 1.91
8 Female 75 2.75 1.73 7.57 30.26 1.95
9 Male 82 2.23 3.42 6.86 27.23 1.82
10 Male 52 2.64 2.92 8.14 35.99 1.99
11 Female 65 2.75 3.22 7.33 31.98 1.85
12 Female 87 2.45 3.37 8.16 36.11 1.97
13 Female 62 2.57 3.03 7.13 30.42 1.84
14 Male 55 2.41 3.21 8.09 35.78 1.98
15 Female 78 2.36 1.89 8.00 35.75 1.93
16 Female 66 2.04 2.41 7.92 34.67 1.96
17 Male 54 2.77 2.75 6.98 25.25 1.68
18 Female 45 3.96 2.85 7.81 34.18 1.95
19 Female 80 3.37 2.50 8.24 36.57 1.98
20 Male 89 3.53 2.65 7.20 29.33 1.84
21 Female 65 2.90 1.98 8.03 35.83 1.96
22 Female 75 2.16 3.18 7.18 29.88 1.84
23 Male 82 3.38 2.71 7.95 34.69 1.94
24 Female 52 2.08 3.24 8.26 36.58 1.99
25 Male 56 2.42 2.15 6.95 27.43 1.77
26 Male 67 2.03 3.02 7.86 34.24 1.90
27 Male 52 2.03 3.35 8.12 36.05 1.98
28 Male 65 2.80 2.47 8.26 36.84 2.00
29 Male 63 2.42 2.93 7.67 31.70 1.93
30 Male 70 1.36 2.59 7.83 30.37 1.88
31 Female 59 2.38 3.29 4.13 21.11 1.23
32 Male 56 2.75 2.44 7.88 34.88 1.94
33 Male 70 1.42 1.51 8.01 35.60 1.95
34 Female 77 2.20 2.31 7.58 34.42 1.89
35 Female 56 1.71 2.97 8.14 35.93 1.98
36 Female 52 2.92 3.25 7.12 26.40 1.86



37 Female 77 1.56 2.48 8.03 34.76 1.96
38 Female 87 2.42 3.34 8.13 36.08 1.94
39 Male 77 2.01 2.38 7.89 34.64 1.93
40 Male 52 3.50 2.62 7.17 29.30 1.81
41 Male 52 2.05 3.21 8.23 36.55 1.96
42 Female 72 2.39 2.12 6.92 27.40 1.74
43 Female 58 2.77 2.44 8.23 36.81 1.97
44 Male 63 1.33 2.56 7.80 30.34 1.85
45 Female 58 2.35 3.26 4.10 21.08 1.20
46 Female 58 1.39 1.48 7.98 35.57 1.92
47 Male 86 2.17 2.28 7.55 34.39 1.86
48 Female 59 2.18 3.20 7.34 28.72 1.87
49 Male 78 2.47 2.84 8.22 36.43 1.96
50 Female 79 2.64 3.13 7.54 29.72 1.88
51 Male 77 2.20 3.39 6.83 27.20 1.79
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Table 4.

The level of microelements in enrolled Female patients.

Number Gender Age Ca2+ (μM) Mg2+ (μM) Zn (ng/ml) VD3 (nM) PTH (ng/ml)
1 Female 62 2.21 3.23 7.37 28.75 1.90
2 Female 83 2.56 2.87 7.76 34.36 1.95
3 Female 75 2.50 2.87 8.25 36.46 1.99
8 Female 75 2.75 1.73 7.57 30.26 1.95
11 Female 65 2.75 3.22 7.33 31.98 1.85
12 Female 87 2.45 3.37 8.16 36.11 1.97
13 Female 62 2.57 3.03 7.13 30.42 1.84
15 Female 78 2.36 1.89 8.00 35.75 1.93
16 Female 66 2.04 2.41 7.92 34.67 1.96
18 Female 45 3.96 2.85 7.81 34.18 1.95
19 Female 80 3.37 2.50 8.24 36.57 1.98
21 Female 65 2.90 1.98 8.03 35.83 1.96
22 Female 75 2.16 3.18 7.18 29.88 1.84
24 Female 52 2.08 3.24 8.26 36.58 1.99
31 Female 59 2.38 3.29 4.13 21.11 1.23
34 Female 77 2.20 2.31 7.58 34.42 1.89
35 Female 56 1.71 2.97 8.14 35.93 1.98
36 Female 52 2.92 3.25 7.12 26.40 1.86
37 Female 77 1.56 2.48 8.03 34.76 1.96
38 Female 87 2.42 3.34 8.13 36.08 1.94
42 Female 72 2.39 2.12 6.92 27.40 1.74
43 Female 58 2.77 2.44 8.23 36.81 1.97
45 Female 58 2.35 3.26 4.10 21.08 1.20
46 Female 58 1.39 1.48 7.98 35.57 1.92
48 Female 59 2.18 3.20 7.34 28.72 1.87
50 Female 79 2.64 3.13 7.54 29.72 1.88
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Table 5.

The level of microelements in enrolled male patients.

Number Gender Age Ca2+ (μM) Mg2+ (μM) Zn (ng/ml) VD3 (nM) PTH (ng/ml)
4 Male 50 2.81 1.54 8.04 35.11 1.96
5 Male 71 2.75 1.18 8.19 36.27 1.99
6 Male 89 2.58 3.34 6.58 25.92 1.65
7 Male 65 2.67 3.16 7.57 29.75 1.91
9 Male 82 2.23 3.42 6.86 27.23 1.82
10 Male 52 2.64 2.92 8.14 35.99 1.99
14 Male 55 2.41 3.21 8.09 35.78 1.98
17 Male 54 2.77 2.75 6.98 25.25 1.68
20 Male 89 3.53 2.65 7.20 29.33 1.84
23 Male 82 3.38 2.71 7.95 34.69 1.94
25 Male 56 2.42 2.15 6.95 27.43 1.77
26 Male 67 2.03 3.02 7.86 34.24 1.90
27 Male 52 2.03 3.35 8.12 36.05 1.98
28 Male 65 2.80 2.47 8.26 36.84 2.00
29 Male 63 2.42 2.93 7.67 31.70 1.93
30 Male 70 1.36 2.59 7.83 30.37 1.88
32 Male 56 2.75 2.44 7.88 34.88 1.94
33 Male 70 1.42 1.51 8.01 35.60 1.95
39 Male 77 2.01 2.38 7.89 34.64 1.93
40 Male 52 3.50 2.62 7.17 29.30 1.81
41 Male 52 2.05 3.21 8.23 36.55 1.96
44 Male 63 1.33 2.56 7.80 30.34 1.85
47 Male 86 2.17 2.28 7.55 34.39 1.86
49 Male 78 2.47 2.84 8.22 36.43 1.96
51 Male 77 2.20 3.39 6.83 27.20 1.79
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3.2. The level of BMP2, BMP7 and the percent of STRO-1+ cells

Next, we evaluated the expression level of BMP2 and BMP7 in the culture medium of extracted cell by using ELISA. And we also sorting the STRO-1+ cells by applying flow cytometric analysis. All the data are presented in Table 1.

3.3. The correlation between microelements and BMD

We analysis the correlation between those microelements and BMD. As demonstrated in Table 6, in Zone 1 when followed up for six months, the level of VD3 (r = 0.326, P = 0.019), PTH (r = 0.325, P = 0.020) and Zinc (r = 0.346, P = 0.013) was positively correlated with BMD; in Zone 2, no significantly relationship between those microelements and BMD; in Zone 3, the level of Mg2+ and Zinc was positively correlated with BMD when followed up for three months (r = 0.294, P = 0.036; r = 0.285, P = 0.043, respectively) and six months (r = 0.292, P = 0.038; r = 0.284, P = 0.050, respectively); in Zone 4, only the level of Zinc at the follow-up time of three month was positively correlated with BMD (r = 0.317, P = 0.023); in Zone 5, only the level of Zine at the follow-up time of three and twelve months was positively correlated with BMD (r = 0.305, P = 0.029; r = 0.288, P = 0.040, respectively); in Zone 6, the level of Ca2+ at the follow-up time of six and twelve months was positively correlated with BMD (r = 0.290, P = 0.039; r = 0.279, P = 0.048, respectively) and the level of PTH and Zinc at the follow-up time of twelve months was positively correlated with the level of BMD (r = 0.280, P = 0.022; r = 0.321, P = 0.022, respectively); and in Zone 7, the level of VD3, PTH, Zinc was positively correlated with BMD at the follow-up time of one (r = 0.571, P = 0.025; r = 0.280, P = 0.047; r = 0.456, P = 0.001, respectively), three (r = 0.557, P = 0.001; r = 0.370, P = 0.008; r = 0.447, P = 0.001, respectively), six (r = 0.551, P = 0.001; r = 0.352, P = 0.011; r = 0.437, P = 0.001, respectively) and twelve months (r = 0.541, P = 0.001; r = 0.343, P = 0.014; r = 0.420, P = 0.002, respectively).

Table 6.

The correlation between microelements and BMD.

Microelements Zone1
1 W 3 M 6 M 12 M
Calcium (μM) r 0.06861 −0.013 0.040 0.031
P 0.6324 0.930 0.780 0.829
Magnesium (μM) r −0.19171 −0.070 −0.001 −0.053
P 0.1778 0.627 0.994 0.712
VD3 (nM) r 0.241 0.166 0.229 0.326
P 0.089 0.244 0.107 0.019
PTH (ng/mL) r 0.107 0.170 0.211 0.325
P 0.898 0.287 0.697 0.020
Zinc (ng/mL) r 0.121 0.150 0.217 0.346
P 0.399 0.294 0.127 0.013
Microelements Zone 2
1 W 3 M 6 M 12 M
Calcium (μM) r 0.013 0.149 0.042 0.115
P 0.928 0.298 0.768 0.422
Magnesium (μM) r 0.040 0.088 0.028 0.017
P 0.778 0.541 0.847 0.905
VD3 (nM) r −0.111 −0.180 −0.115 −0.291
P 0.437 0.205 0.422 0.038
PTH (ng/mL) r −0.109 −0.069 −0.079 −0.167
P 0.447 0.630 0.582 0.241
Zinc (ng/mL) r −0.098 −0.096 −0.068 −0.184
P 0.493 0.501 0.636 0.195
Microelements Zone 3
1 W 3 M 6 M 12 M
Calcium (μM) r 0.237 0.294 0.292 0.248
P 0.094 0.036 0.038 0.079
Magnesium (μM) r 0.067 0.007 −0.002 0.066
P 0.638 0.963 0.989 0.644
VD3 (nM) r −0.104 −0.009 −0.036 −0.151
P 0.466 0.952 0.804 0.289
PTH (ng/mL) r −0.030 0.269 0.251 −0.042
P 0.833 0.050 0.076 0.767
Zinc (ng/mL) r −0.059 0.285 0.274 −0.074
P 0.680 0.043 0.050 0.607
Microelements Zone 4
1 W 3 M 6 M 12 M
Calcium (μM) r 0.149 0.030 0.144 0.041
P 0.297 0.837 0.314 0.777
Magnesium (μM) r −0.016 −0.020 −0.003 0.039
P 0.914 0.890 0.981 0.784
VD3 (nM) r −0.132 −0.026 −0.102 −0.129
P 0.356 0.854 0.478 0.367
PTH (ng/mL) r −0.074 0.057 −0.001 0.005
P 0.608 0.692 0.994 0.972
Zinc (ng/mL) r −0.071 0.317 0.255 0.236
P 0.621 0.023 0.070 0.096
Microelements Zone 5
1 W 3 M 6 M 12 M
Calcium (μM) r 0.246 0.155 0.236 0.196
P 0.082 0.276 0.096 0.167
Magnesium (μM) r −0.036 −0.012 0.005 0.032
P 0.804 0.936 0.971 0.821
VD3 (nM) r −0.102 −0.029 −0.134 −0.157
P 0.477 0.840 0.350 0.271
PTH (ng/mL) r −0.045 0.255 −0.079 −0.066
P 0.752 0.070 0.580 0.645
Zinc (ng/mL) r 0.219 0.305 0.258 0.288
P 0.122 0.029 0.067 0.040
Microelements Zone 6
1 W 3 M 6 M 12 M
Calcium (μM) r 0.168 0.105 0.290 0.279
P 0.240 0.463 0.039 0.048
Magnesium (μM) r 0.088 0.071 0.091 0.147
P 0.539 0.621 0.524 0.302
VD3 (nM) r 0.050 0.246 −0.039 0.241
P 0.726 0.081 0.786 0.088
PTH (ng/mL) r 0.056 0.125 0.038 0.280
P 0.694 0.381 0.789 0.046
Zinc (ng/mL) r 0.192 0.238 0.045 0.321
P 0.176 0.093 0.754 0.022
Microelements Zone 7
1 W 3 M 6 M 12 M
Calcium (μM) r 0.019 0.029 0.026 0.034
P 0.895 0.839 0.857 0.815
Magnesium (μM) r 0.116 0.112 0.129 0.116
P 0.416 0.435 0.367 0.418
VD3 (nM) r 0.571 0.557 0.551 0.541
P 0.025 0.001 0.001 0.001
PTH (ng/mL) r 0.280 0.370 0.352 0.343
P 0.047 0.008 0.011 0.014
Zinc (ng/mL) r 0.456 0.447 0.437 0.420
P 0.001 0.001 0.001 0.002
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3.4. The correlation between microelements and BMP2, BMP7 and STRO-1+ cells

We analyzed the correlation between microelements and BMP2. As demonstrated in Table 7, none of the microelements was correlated with BMP2. Then we analyzed the correlation between microelements and BMP7. We found that the level of Ca2+ was positively correlated with the level of BMP7 (r = 0.32448, p = 0.0202); the level of Mg2+ was negatively correlated with the level of BMP7 (r = -0.30196, p = 0.0313); while the level of Zinc, VD3 and PTH showed no significant correlation with BMP7. Additionally, we also analyzed the correlation between those microelements with STRO-1+ cells. We revealed that the level of Ca2+ was positively correlated with the percent of STRO-1+ cells (r = 0.28654, p = 0.0415); and the level of VD3 was positively correlated with the percent of STRO-1+ cells (r = 0.2683, p = 0.050); while the level of Mg2+, Zinc and PTH exerted no significantly correlation with STRO-1+ cells. All the data were present in Table 7.

Table 7.

The correlation between microelements and BMP2, BMP7 and STRO-1+ cells.

Ca2+ (μM) Mg2+ (μM) Zn2+ (ng/mL) VD3 (nM) PTH (ng/ml)
BMP2 r −0.1816 −0.03489 −0.04287 0.09361 −0.09286
P 0.2022 0.808 0.7652 0.5135 0.5169
BMP7 r 0.32448 −0.30196 0.16096 0.24256 0.11778
P 0.0202 0.0313 0.2592 0.0864 0.4104
Stro-1(%) r 0.28654 −0.13449 0.19462 0.2683 0.1763
P 0.0415 0.3467 0.1711 0.05 0.2158
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4. Discussion

Hip replacement is one of the most commonly used adult joint reconstruction surgery, which has been widely used for the treatment of severe arthritis, rheumatoid arthritis, aseptic necrosis of femoral head. With the improvement of surgical technique and the normalization of perioperative treatment, the incidence of early complications like infection, hip dislocation and sciatic nerve injury has been decreased significantly. However, due to many factors such as the fabrication process, biomechanics and the ability of individual bone reconstruction, long-term complications such as prosthesis loosening still have a high incidence (Chen et al., 2017, Hoskins et al., 2017, Bovonratwet et al., 2018, Lovelock and Broughton, 2018, Makela et al., 2014). At present, the research mechanism for aseptic loosening after the hip replacement surgery is mainly summarized into mechanistic and biological factors. In terms of the mechanistic factors, fretting wear, prosthetic wear, stress shielding and the size, materials, properties and surface features of the prosthesis may cause osteolysis. Among the biological factors, the generation and diffusion of wear debris, the histogenesis of interfacial film, osteoclast activation and osteolysis as well as certain cytokines are key inducers. In brief, all of the researches above are mainly focused on prosthesis design, fixation techniques and wear debris. Nevertheless, patients themselves are not included. This study discussed the prophylaxis for aseptic loosening of hip prosthesis on the basis of the basic and clinical research of patients.

In our study, we determined the BMD and measured the level of microelements in all 51 enrolled patients and also the level of BMP2, BMP7 and the percent of STOR-1+ cells. Based on our data, we found that not all the microelements were correlated with BMD. The correlation between microelements were dependent on the Zone. In Zone 7, the level of VD3, PTH, Zinc was positively correlated with BMD. And in our study, we found that the level of all the detected microelements was not correlated with BMP2 but some microelements like Ca2+ and Mg2+was correlated with the level of BMP7 and Ca2+ and VD3 was correlated with the percent of STOR-1+ cells. It was found that active VD3 maintained the stability of serum calcium and phosphorus concentration. When serum calcium concentration was low, PTH secretion was induced and released to kidney and bone cells. Calcium, as the raw material of osteogenesis, is closely related to osteogenesis. Vitamin D promotes the absorption of calcium and phosphorus, mobilizes calcium and phosphorus from bone, makes the plasma calcium and phosphorus reach the normal value, and promotes bone mineralization and constantly renews.

In general, our study revealed that microelements might be associated with the prosthesis loosening and we hope our study will be useful for exploring novel therapy method for clinical treatment of prosthesis loosening.

Declaration of Competing Interest

There is no conflicts of interest.

Acknowledgement

This work was supported by National natural breeding project of Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine (2017PYM08).

Footnotes

Peer review under responsibility of King Saud University.

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