Ruggero Cadossi

Phalangeal Osteosonogrammetry Study: Age‐Related Changes, Diagnostic Sensitivity, and Discrimination Power

Phalangeal osteosonogrammetry was introduced as a method for bone tissue investigation in 1992. It is based on the measure of the velocity of ultrasound (amplitude‐dependent speed of sound [AD‐SoS]) and on the interpretation of the characteristics of the ultrasound signal. In this study we have collected a database of 10,115 subjects to evaluate the performance of AD‐SoS and to develop a parameter that is able to quantify the signal characteristics: ultrasound bone profile index (UBPI). The database only includes females of which 4.5% had documented vertebral osteoporotic fractures, 16% lumbar spine dual X‐ray absorptiometry (DXA), and 6% hip DXA. The analysis of the ultrasound signal has shown that with aging the UBPI, first wave amplitude (FWA), and signal dynamics (SDy) follow a trend that is different from the one observed for AD‐SoS; that is, there is no increase during childhood. In the whole population, the risk of fracture per SD decrease for AD‐SOS was odds ratio (OR) 1.71 (CI, 1.58‐1.84). The AD‐SoS in fractured subjects was significantly lower than in a group of age‐matched nonfractured subjects (p < 0.0001). In a small cohort of hip‐fractured patients UBPI proved to be lower than in a control age‐matched group (p < 0.0001). When the World Health Organization (WHO) working group criteria were applied to this population to identify the T score value for osteoporosis, for AD‐SoS we found a T score of −3.2 and for UBPI we found a T score of −3.14. Sixty‐six percent of vertebral fractures were below the AD‐SoS −3.2 T score and 62% were below UBPI −3.14. We observed the highest incidence of fractures (63.6%) among subjects with AD‐SoS who had both DXA T score values below the threshold. We conclude from this study that ultrasound investigation at the hand phalanges is a valid methodology for osteoporosis assessment. It has been possible to quantify signal changes by means of UBPI, a parameter that will improve the possibility of investigating bone structure.

Lymphocytes and low-frequency electromagnetic fields.

Human lymphocytes have been used by several researchers to investigate the biological effect of electromagnetic fields (EMF). EMF modulate the response by lymphocytes to lectin stimulation. The size and direction of the effect depends both on the lymphocyte physiology and on the physical parameters characterizing the EMF. Lymphocytes have also been used to investigate the genotoxicity of EMF exposure.— Cadossi, R.; Bersani, F.; Cossarizza, A.; Zucchini, P.; Emilia, G.; Torelli, G.; Franceschi, C. Lymphocytes and low‐frequency electromagnetic fields. FASEB J. 6: 2667‐2674; 1992.

Extremely low frequency pulsed electromagnetic fields increase cell proliferation in lymphocytes from young and aged subjects.

The effect of the in vitro exposure to extremely low frequency pulsed electromagnetic fields (PEMFs) on the proliferation of human lymphocytes from 24 young and 24 old subjects was studied. The exposure to PEMFs during a 3-days culture period or during the first 24 hours was able to increase phytohaemagglutinin-induced lymphocyte proliferation in both groups. Such effect was greater in lymphocytes from old people which showed a markedly reduced proliferative capability and, after PEMF exposure, reached values of 3H-TdR incorporation similar to those of young subjects. The relevance of these data for the understanding and the reversibility of the proliferative defects in cells from aged subjects and for the assessment of risk related to the environmental exposure to PEMFs has to be considered.

Effect of low frequency electromagnetic fields on A2A adenosine receptors in human neutrophils

The present study describes the effect of low frequency, low energy, pulsing electromagnetic fields (PEMFs) on A2A adenosine receptors in human neutrophils. Saturation experiments performed using a high affinity adenosine antagonist [3H]‐ZM 241385 revealed a single class of binding sites in control and in PEMF‐treated human neutrophils with similar affinity (KD=1.05±0.10 and 1.08±0.12 nM, respectively). Furthermore, after 1 h of exposure to PEMFs the receptor density was statistically increased (P<0.01) (Bmax =126±10 and 215±15 fmol mg−1 protein, respectively). The effect of PEMFs was specific to the A2A adenosine receptors. This effect was also intensity, time and temperature dependent. In the adenylyl cyclase assays the A2A receptor agonists, HE‐NECA and NECA, increased cyclic AMP accumulation in untreated human neutrophils with an EC50 value of 43 (40 – 47) and 255 (228 – 284) nM, respectively. The capability of HE‐NECA and NECA to stimulate cyclic AMP levels in human neutrophils was increased (P<0.01) after exposure to PEMFs with an EC50 value of 10(8 – 13) and 61(52 – 71) nM, respectively. In the superoxide anion (O2−) production assays HE‐NECA and NECA inhibited the generation of O2− in untreated human neutrophils, with an EC50 value of 3.6(3.1 – 4.2) and of 23(20 – 27) nM, respectively. Moreover, in PEMF‐treated human neutrophils, the same compounds show an EC50 value of 1.6(1.2 – 2.1) and of 6.0(4.7 – 7.5) nM respectively. These results indicate the presence of significant alterations in the expression and in the functionality of adenosine A2A receptors in human neutrophils treated with PEMFs.

Bone quality assessment by quantitative ultrasound of proximal phalanxes of the hand in healthy subjects aged 3-21 years

Bone quality by quantitative ultrasound was assessed in 1083 (587 males) healthy white subjects aged 3–21 y. Amplitude-dependent speed of sound (AD-SoS) through the distal end of the first phalanx diaphysis of the last four fingers of the hand was measured by an ultrasound device (DBM Sonic 1200, IGEA, Carpi, Italy). Mean AD-SoS values increased progressively from 3 to 21 y (males, 1845.9–2119.1 m/s, p < 0.0001; females, 1842.3–2098.8 m/s, p < 0.0001). They did not differ (p = NS) between sexes up to age 11, but females showed higher (p < 0.05 –p < 0.0001) AD-SoS values than males in age groups 12, 13, and 14 y. There was no difference (p = NS) of AD-SoS values between sexes in pubertal stages 1, 2, and 5, but females had higher mean AD-SoS values than males in stages 3 (p < 0.01) and 4 (p < 0.001). Independent predictors of AD-SoS were weight, body mass index, pubertal stage, and mean width of fingers in males, and age, pubertal stage, and mean width of fingers in females (p < 0.01 –p < 0.0001). However, 7.8% in males and 3.6% in females of the increment of AD-SoS values can be related to the finger anatomy alone. AD-SoS values probably reflect the architectural organization of growing bone or changes in bone elasticity. Increased bone density and size may be additional factors influencing AD-SoS. Measurement of AD-SoS at the hand phalanxes may be a simple, noninvasive, and radiation-free technique to assess bone quality in children.

Three-year longitudinal study with quantitative ultrasound at the hand phalanx in a female population

A longitudinal study was conducted to assess the value of quantitative ultrasound (QUS) measurement in predicting the risk of fracture and to evaluate how QUS parameters change with ageing and the climacteric. A group of 211 female subjects underwent assessment by QUS at the distal metaphysis of the first phalanx of the last four fingers of the hand on two occasions 3 years apart. The subjects were selected from outpatients attending the orthopaedic clinic, provided they were not affected by metabolic disease or under treatment with drugs known to interfere with bone metabolism. In vivo the coefficient of variation and the standardized coefficient of variation of the QUS device were respectively 0.5% and 3.5%. The correlation between the values of the amplitude-dependent speed of sound (AD-SoS) in the two measurements wasr=0.92. In 77.3% of the subjects during the observation period we recorded a reduction in AD-SoS. During the study 22 fractures were observed in peripheral sites, 8 of which were associated with ‘low-energy trauma’. By multiple logistic regression analysis we found that the relative risk of fracture for a 1 SD reduction in AD-SoS was 1.5 (95% CI 1.1–1.7) (p<0.03). The percentage of low-energy fractures significantly increased among those subjects with an AD-SoS value lower than 1850 m/s (T-score <−3.5) at the first examination (p<0.0001). QUS investigation proved to be especially sensitive to hormonal changes associated with the climacteric: we observed a mean decrease of 56 m/s in the AD-SoS for women who entered the menopause between the first and the second QUS test (average time since menopause 2 years), as against 10 m/s in subjects remaining premenopausal. In a group of 146 subjects with ‘normal’ AD-SoS at the first examination, we observed a significant reduction in AD-SoS only after 40 years of age. This study demonstrates that measurement of the AD-SoS at the phalanx is reproducible, can be employed to assess the risk of fracture, and is able to detect age-related alterations in bone tissue.

Assessment of bone quality by quantitative ultrasound of proximal phalanges of the hand and fracture rate in children and adolescents with bone and mineral disorders

Bone quality by quantitative ultrasound and fracture rate were assessed in 135 (64 males) children and adolescents aged 3-21 y with bone and mineral disorders such as chronic anticonvulsants or glucocorticoids treatment, juvenile rheumatoid arthritis, celiac disease, paucity of intrahepatic bile ducts, autoimmune hepatitis, genetic diseases, idiopathic juvenile osteoporosis, disuse osteoporosis, β-thalassemia major, survivors of acute lymphoblastic leukemia, liver transplantation, calcium deficiency, and nutritional or X-linked hypophosphatemic rickets. Amplitude-dependent speed of sound through the distal end of the first phalangeal diaphysis of the last four fingers of the hand was measured by an ultrasound device. In the majority of patients cortical area to total area ratio by metacarpal radiogrammetry (n=120) and lumbar bone mineral density (BMD) by dual-energy x-ray absorptiometry (n=99) were also assessed. In patients with X-linked hypophosphatemic rickets radial BMD by single-photon absorptiometry instead of lumbar BMD was measured. Mean values of amplitude-dependent speed of sound, cortical area to total area ratio, lumbar BMDarea, or lumbar BMD corrected for bone sizes estimated by a mathematical model (BMDvolume), as well as mean values of radial BMD in patients with X-linked hypophosphatemic rickets, expressed as z score, were significantly reduced (p < 0.0001) in comparison with their reference values (−1.7 ± 1.0, −2.0 ± 0.9, −3.0 ± 1.3, −1.9 ± 1.0, −2.7 ± 0.7, respectively). A positive relationship was found between amplitudedependent speed of sound and cortical area to total area ratio (r = 0.90, p < 0.0001), lumbar BMDarea (r = 0.62, p < 0.0001), or lumbar BMDvolume (r = 0.66, p < 0.0001). Fifty-two patients (38.5%) had suffered fractures in the 6 mo preceding the bone measurements, the radial distal metaphysis being the most frequent fracture site (28.8%). Mean values of amplitude-dependent speed of sound, cortical area to total area ratio, lumbar BMDarea, or lumbar BMDvolume, expressed as z score, of fractured patients were significantly lower (p < 0.0001) than those of fracture-free patients (−2.2 ± 1.0 and −1.4 ± 0.8, −2.6 ± 0.9 and −1.7 ± 0.7, −3.5 ± 1.2 and −2.5 ± 1.0, −2.5 ± 1.0 and −1.3 ± 0.7, respectively). Phalangeal quantitative ultrasound may be a useful method to assess bone quality and fracture risk in children and adolescents with bone and mineral disorders.

Effects of pulsed electromagnetic fields on human chondrocytes: an in vitro study.

Abstract.3H-thymidine incorporation was studied in cultured human nasal and articular chondrocytes exposed to low-energy, low-frequency pulsed electromagnetic fields (PEMFs) (75 Hz, 2.3 mT). The reverse transcriptase polymerase chain reaction (RT-PCR) analysis shows that human secondary chondrocytes derived from both nasal and articular cartilage express collagen type II mRNA, which is a specific marker of the chondrocyte phenotype. In a preliminary series of experiments, cells were exposed to PEMF for different time periods ranging from 6 to 30 hours (time-course), in medium supplemented with 10% or 0.5% fetal calf serum (FCS) and in serum-free medium. The ratios between the 3H-thymidine incorporation in PEMFs and control cultures show an increase of the cell proliferation in cultures exposed to PEMFs when serum is present in the culture medium, whereas no effect was observed in serum-free conditions. The increase in DNA synthesis, induced by PEMFs, was then evaluated only at the times of maximum induction and the results were analyzed by the three-factor analysis of variance (ANOVA).The data presented in this study show that even if 3H-thymidine incorporation is higher in nasal than in articular chondrocytes, PEMF induce an increase in the proliferation of both cell types. Moreover, the concentration of FCS in the culture medium greatly influences the proliferative response of human chondrocytes to the PEMF exposure. Though normal human osteoblast cells increase their proliferation when exposed to PEMFs if only 10% FCS is present in the medium, human chondrocytes are able to increase their cell proliferation when exposed to PEMFs in the presence of both 0.5% and 10% of FCS in the medium. The results obtained may help to explain the basic mechanisms of PEMF stimulation of fracture healing.

German Pediatric Reference Data for Quantitative Transverse Transmission Ultrasound of Finger Phalanges

Abstract: Quantitative ultrasound (QUS) of the finger phalanges is a useful tool in the assessment of disease- or age-related deterioration of bone. For studying the impact of juvenile diseases or growth disorders affecting the skeleton, a reference database for QUS parameters is needed. The aim of this study was to establish a calibrated reference database of parameters of transverse ultrasound transmission through juvenile finger phalanges. A total of 1328 children (650 females, 678 males; ages 3–17 years) were measured in Heidelberg and Kiel in order to establish a German reference database. Highly significant gender-specific correlations (p<0.0001) were found between the QUS parameters amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) versus age, body height and body mass index (BMI). For AD-SoS the correlation coefficients were R2= 0.64 against age in males and R2= 0.73 in females, R2= 0.60 against body height in males and R2= 0.68 in females, and R2= 0.19 against BMI in males and R2= 0.23 in females. For BTT the correlation coefficients were R2= 0.74 against age in males and R2= 0.79 in females, R2= 0.75 against body height in males and R2= 0.77 in females, and R2= 0.32 against BMI in males and R2= 0.35 in females. Age and height were the strongest determinants of QUS results. Gender-specific differences were observed in AD-SoS (significant for ages 11–14 years and for 150–170 cm body height) and in BTT (significant for ages 7 and 11–17 years and for 160–170 cm body height). Tables of QUS parameters versus age and height can serve as a basis for the evaluation of the impact of skeletal diseases or growth disorders on phalangeal QUS. Depending on the type of disease or growth disorder, measurement results can be compared with age- or height- specific reference data. In this way a simple and radiation-free assessment of juvenile skeletal disorders using quantitative ultrasound might be possible in the future.

Biophysical stimulation with pulsed electromagnetic fields in osteonecrosis of the femoral head

BACKGROUND Osteonecrosis of the femoral head is the end point of a disease process that results in bone necrosis, joint edema, and cartilage damage. It leads to joint arthritis that necessitates total hip arthroplasty in many patients. Because of its positive effects on osteogenesis and its chondroprotective effect of articular cartilage, pulsed electromagnetic field stimulation has been proposed as a method to prevent or delay the progression of osteonecrosis. METHODS A retrospective analysis of the results of treatment with pulsed electromagnetic field stimulation of seventy-six hips in sixty-six patients with osteonecrosis of the femoral head was performed. Patients with Ficat stage I, II, or III osteonecrosis of the femoral head were treated with pulsed electromagnetic field stimulation for eight hours per day for an average of five months. Clinical and diagnostic imaging information was collected at the start of the treatment and at the time of follow-up. The primary end point analyzed was the avoidance of hip surgery, and the secondary end point was limiting the radiographic progression (according to Ficat stage) of osteonecrosis of the femoral head. RESULTS Fifteen hips required a total hip arthroplasty; twelve of these hips were in patients with Ficat stage-III disease. The need for total hip arthroplasty was significantly higher in patients with Ficat stage-III disease than in patients with Ficat stage-I (p < 0.0001) or II (p < 0.01) disease at the beginning of treatment. Pulsed electromagnetic fields preserved 94% of Ficat stage-I or II hips. Furthermore, radiographic progression (according to Ficat stage) occurred in twenty hips (26%). Pain, present in all patients at the start of the treatment, disappeared after sixty days of stimulation in thirty-five patients (53%) and was of moderate intensity in seventeen patients (26%). CONCLUSIONS The results of this study confirm that pulsed electromagnetic field treatment may be indicated in the early stages of osteonecrosis of the femoral head (Ficat stages I and II). Pulsed electromagnetic field stimulation may be able to either preserve the hip or delay the time until surgery. The authors hypothesize that the short-term effect of pulsed electromagnetic field stimulation may be to protect the articular cartilage from the catabolic effect of inflammation and subchondral bone-marrow edema. The long-term effect of pulsed electromagnetic field stimulation may be to promote osteogenic activity at the necrotic area and prevent trabecular fracture and subchondral bone collapse. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.