Osteological evidence for spinal tuberculosis in medieval skeletal series from Croatia
Željka Bedić, Department of archaeology, Croatian Academy of Sciences and Arts, Zagreb, Croatia
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis that is most often transmitted through the respiratory system. The primary infection usually starts in the lungs, after which it disseminates by the blood stream to other parts of the body – the kidneys, brain and bones. The spine is the most common (in approximately 40% of cases) affected bone element (Aufderheide & Rodriguez-Martin, 1998). In most cases of spinal tuberculosis an abscess erodes the anterior part of the vertebral body and the intervertebral disc, ultimately resulting in destruction of the vertebral body and the development of the characteristic gibbus of Pott’s disease. In pre-antibiotic times this deformity was present in nearly 60% of cases involving spinal tuberculosis (Reinhart, 1932). This report presents four unambiguous cases of spinal tuberculosis recovered from four medieval sites in Croatia.
Salvage excavations conducted in 1978 at the Stari Jankovci site in continental Croatia revealed the presence of 95 Avaro – Slavic graves dated to the period between the 7th and 8th centuries (Šmalcelj, 1981). One individual, a female aged between 20 to 30 years recovered from grave 37, exhibits clear osteological signs of tuberculosis in the thoracic, and lumbar parts of the spine. Six thoracic vertebrae (T5-T10) collapsed resulting in ankylosis and a sharply angled kyphosis (gibbus). The first lumbar vertebra is also destroyed and fused with T12 and L2. The vertebra immediately below (L3) exhibits increased height (it is 31 mm high compared to the 28 mm recorded in L4) that was most likely caused by compensatory growth suggesting that the changes caused by tuberculosis in this part of the spine occurred in childhood (Ortner, 2003).
The cemetery of Velim near Benkovac in the hinterland of the Adriatic coast was excavated from 2004 – 2009 and revealed 121 graves. According to recovered archaeological artefacts use of the cemetery was dated to the 8th and 9th centuries (Jurić, 2004). The skeleton of a female aged between 50-60 years exhibits evidence of spinal tuberculosis. The 8th thoracic vertebra collapsed resulting in ankylosis and gibbus with T9 and T10. Another ankylosis is present in T6 and T7.
The third case is from the St. Anselmo cemetery in Nin on the eastern Adriatic coast whose use was dated to the period between the 12th and 15th centuries (Kolega, 2001). The skeleton of an adult female aged between 30-40 years recovered from grave 17 exhibits pathological changes characteristic for tuberculosis. The T7, T8 and T9 collapsed and fused resulting in a clear gibbus. This block is fused with one superior (T6) and three inferior vertebrae (T10-12) giving a total of 7 fused vertebrae.
In 2002 and 2003 archaeological excavations in Stari grad on the island Pag recovered 116 skeletons from 14 communal tombs. On the basis of a variety of finds that include earrings, belt-straps, a razor, rings, pendants, and a knife, the use of this cemetery is dated to the period between 12th-14th century. The skeleton of a 30-40 years old female also has changes typical for spinal tuberculosis. Thoracic vertebrae T4-T10 are completely destroyed resulting in a sharply angular kyphosis. In this case 11 thoracic vertebrae are fused together.
All of the described cases exhibited one or more collapsed vertebrae resulting in both ankylosis and sharply angular kyphosis (gibbus) of the thoracic spine. In all four cases the vertebral arches, including the joints and spinous processes are intact with secondary bony ankylosis between them.
Differential diagnosis excluded osteomyelitis, vertebral compression fracture, rheumatoid and septic arthritis, and other diseases that affect the spine. Osteomyelitis of the spine usually manifests as a destructive lesion of just one vertebra and does not end with ankylosis and kyphosis. In vertebral compression fractures with angular deformity usually only one vertebra is involved, and the vertebral body is generally destroyed to a lesser degree. If rheumatoid arthritis affects the spine then the most marked changes occur in the diarthrodial joints of the cervical spine. Although septic arthritis often terminates in bony ankylosis and is very similar to tuberculosis arthritis, bone destruction is not that severe as in tuberculosis.
References:
Aufderheid AC., Rodrigez-Martin C. (1998). The Cambridge Encyclopedia of Human Paleopathology. Cambridge: Cambridge University Press, pp. 121.
Reinhart M. (1932). Die Fälle von Spondylitis Tuberculosa in der Aargauischen Heilstätte Barmelweid aus den Jahren 1912-1930. Beitrage zur Klinik der Tuberkulose, 79: pp. 745-749.
Šmalcelj M. (1981). Stari Jankovci – Gatina (općina Vinkovci) – avaroslavenska nekropola. Arheološki pregled, 22: pp. 142-143.
Ortner D. (2003). Identification of pathological conditions in human skeletal remains. San Diego: Academic press.
Jurić R. (2004). Ranosrednjovjekovno groblje u Velimu kod Benkovca. Obavijesti Hrvatskog arheološkog društva, 2: pp. 20.
Kolega M. (2001). Nin – arheološka istraživanja u sklopu župne crkve Sv. Asela (Anselma). Obavijesti Hrvatskog arheološkog društva, 2: pp. 83-90.