The anthropological analysis of Paccherotti’s remains underlined the presence of many characteristics related to castration: high stature, open epiphyseal lines in the hips, lower cortical bone density related to vertebral fractures. That “castrati” were particularly tall has been known since antiquity22, even Aristotle observed that “all animals, if operated on when young, become bigger than their unmutilated fellows”23. At the beginning of the XX century, the Skoptzy, a Christian sect practicing male castration, were measured and they appeared to be taller than their peers24. The persistence of the epiphyseal lines was also found in the iliac crest of another castrato singer, Farinelli5 and can be considered as a typical marker in young age castrati (Fig. 3). Tandler and Grosz at the beginning of the XX century described the failure of closure of the epiphyses in the skeleton of eunuchs25,26. Sex hormones preserve bones, at least in part, by regulating the development and death (apoptosis) of osteoclasts and osteoblasts; this adjustment is permitted by the modification of cytokine production and of the sensitivity of bone marrow progenitor cells to cytokines themselves. For example, the production of interleukin-6 (IL-6) by the osteoblasts is inhibited by estrogen and androgen. After menopause or following castration in men, bone loss increases by 10 times, largely due to overproduction of IL-6. The estrogen deficiency seems to delay osteoclasts apoptosis, while promoting the osteoblast: it follows an imbalance between reabsorption and bone formation. In addition, the delay of osteoclasts apoptosis could be responsible for an increase in the depth of the cavities of resorption, and, consequently, of the trabecular perforation resulting from estrogen deficiency27. It is known the existence of a hormonal crosstalk between bone and testis; it includes testosterone and vitamin D that, released by the testes, affect bone remodeling and the bone-derived hormone osteocalcin that may control testosterone production28.

Characteristics of castration’s bone loss are vertebral fractures, as revealed with the CT scan (L1 and L2), but also the micro-CT found a decrease in cortical bone density, especially in long bones as tibiae and humeri (Fig. 8). The CT scan demonstrates a diffuse osteoporosis affecting both the cortical and the cancellous bone. This is different from senile osteoporosis, where remnants of a normal bone would be seen as microfractures as well as repairs. In fact, X-ray’s results are remarkable because of the relative absence of osteoporotic microfractures. This suggests a long-standing adaptation.

Figure 8 Tibia with a decrease of cortical bone density. Full size image

Bone mineral density progressively decreases after castration, particularly in the first few years, causing osteoporosis29. As in Pacchierotti, a study by Stepan et al., found a progressive loss of the lumbar bone density after orchiectomy29. Kock, studying the men of Skoptzy sect with X-ray, found that kyphosis was common because of osteoporosis30. The same kyphosis was observed by Wagenseil in 20 out of the 31 Chinese eunuchs31.

Osteoporosis is clearly proved also in experimental rats. One-year-old castrated rats developed pronounced femoral osteoporosis 4 months after castration32. Finally, orchiectomy for prostate cancer is frequently followed by severe osteoporosis33.

In the study of Farinelli5, it was found, in a fragment of the frontal bone, a severe hyperostosis frontalis interna (HFI) that the authors related to the castration of the singer, but there were no signs of this pathology in the skull of Pacchierotti. Since the HFI can have different aetiologies34, we can assume that HFI is not always correlated with castration. Moreover, Kock, in the already mentionedstudy on Skoptzy, reported that in all of them was evident the thinning of the bones of the skull30.

Pacchierotti’s activity as singer determined some changes in his body and bones. We discovered modifications in the insertion of three important respiratory muscles: scalenus posterior, serratus anterior and serratus posterior superior. Pettersen in different studies found equivalent modifications of scalenus and serratus in professional opera singers by measuring the electromyographic activity35,36.

Pacchierotti’s cervical vertebrae were all strongly eroded, as demonstrated by the osteophytic lipping revealed from the CT scan. According to Miller et al.37, who measured by Magnetic resonance imaging (MRI) pitch-related adjustments in ten healthy volunteers, high note humming was accompanied by increased craniocervical angles. In singing, the position of the atlas with respect to the true vertical (P < 0.001), the axis (P < 0.001) and the C4 vertebra both with respect to the horizontal (P < 0.001) and the axis with respect to the cranium (P < 0.001), were all significantly different to those at rest38. This prolonged condition in Pacchierotti, combined with his osteoporosis, can account for the eroded states of his cervical vertebrae. Di Carlo carried out a systematic X-ray study of cervical spine of three populations of subjects (professional singers, beginning singers and non-singers), which showed deformations of cervical spine after many years of intensive singing39.

According to research in phoniatrics40,41, the ideal posture of the neck in a singer is with the back of the neck elongated compared with the position of the shoulders, so that the rotation of the neck-head is not limited. This technique also permits to avoid passive tilting, lifting or stretching of the laryngeal box, allowing that freedom of management of the glottal-upper glottal system that promotes a greater ease of development of harmonics. An incorrect posture at this level has an influence not only on the stamp, but also on the respiratory dynamics. A correct postural attitude requires the cervical spine to be maintained in an erect position, in nuchal elongation, avoiding the lordosis, the extension and lifting of the jaw. This particular posture determined the progressive erosion of Pacchiarotti cervical vertebrae. A correct postural alignment of the head and neck, in fact, is a necessary element in the optimization of voice production38. Finally, the great bodily size of Pacchiarotti, in particular of his chest, was positively associated with the power of his voice, described as an “extensive soprano”41.

In conclusion, this research describes, for the first time, the occupational markers and the hormonal effect of castration on a whole skeleton of a castrato singer integrating the knowledge about castration in men and animals and its effects on the skeleton. It provides also an enlightening description of the occupational markers of professional singers.

“Today we can but guess what the great singers of the past can have sounded like; but one might hazard a guess that of all the castrati, could we hear them, Pacchierotti would please us most”42.