DIAGNOSING DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH) BEFORE VERTEBRAL ANKYLOSIS Laura Castells Navarro and Jo Buckberry School of Archaeological Sciences, University of Bradford, Bradford, BD7 1DP ID UT12- 90D UT62- 08D UT34- 06D UT43- 09D UT79- 09D UT10- 12D UT40- 10D UT48- 09D UT115- 08D UT53- 08D UT24- 08D UT18- 10D UT25- 00D UT64- 08D UT08- 10D UT42- 07D UT49- 07D UT79- 06D UT01- 11D UT67- 10D UT28- 08D UT58- 09D UT71- 06D UT50- 09D UT58- 08D Age 52 55 56 56 57 61 61 63 64 65 66 67 68 69 71 71 71 73 75 78 79 81 81 88 89 Ancestry W W W W W W W W W W W W W B W W W W W W W W W W W Extra spinal manifestations Elbow Knee Ankle Iliac crest ID UT72- 08D UT03- 08D UT01- 10D UT89- 08D UT117- 10D UT108- 07D UT30- 06D UT113- 07D UT91- 06D UT74- 10D UT86- 08D UT101- 07D Age 55 61 63 67 68 69 75 75 77 82 84 89 Ancestry W W W W W W W W W W W W Extra spinal manifestations Elbow Knee Ankle Iliac crest SUMMARY 1. Analysis of the vertebrae permitted the identification of isolated bone outgrowths commonly located in the lower thoracic and lumbar sections of the spine, originating from at the central third of the anterior surface of the vertebral body. These are vertically orientated and were unaccompanied by intervertebral disc degeneration, following the features observed in the ankylosed segments and differ from normal osteophytes and syndesmophytes. 2. Statistical analysis evaluating the correlation between the severity of spinal and the extra-spinal manifestations suggests that there is no significant correlation between these features (correlation total number of ankylosed vertebrae and L ulna, R/L patellae and R/L calcanei: p > 0.05. Correlation with R ulna: Pearson Cor. = 0.338; p = 0.41). 3. The distribution of ankyloses shifts from a central location at the higher thoracic vertebrae to the right side at the central thoracic and displaced to the lateral thirds in the lower thoracic and lumbar vertebrae. The areas not affected by the main ankylosis can also show smaller abnormal bone outgrowths which are less prone to form a continuous vertebral ankylosis. 4. Finally, the statistical analysis confirms a positive correlation between the number of ankylosed vertebrae and the age of the individual (Pearson Correlation: 0.366; p= 0.026). INTRODUCTION: Diffuse idiopathic skeletal hyperostosis (DISH) is a progressive spondylarthropathy associated with males over 50 years of age (e.g. Julkunen et al 1971, Maat et al 1995). However all the diagnostic criteria used to issue a positive diagnosis indicate that 3 or 4 vertebrae must be ankylosed (e.g Resnick and Niwayama 1975, Rogers and Waldron 1995) thus not considering earlier development of the lesions. This study aims to identify these earlier stages by analysing the features of the spine at either end of the ankylosed spinal fraction and evaluate the relationship between the spinal and the extra-spinal manifestations of DISH. MATERIALS AND METHODS 37 individuals from the WM Bass Donated Skeletal Collection (Knoxville, TN) that have been previously diagnosed with DISH were evaluated. From each individual, the number of vertebrae affected by DISH outgrowths/ ankyloses as well as the presence and nature of isolated bone outgrowths was noted. The presence of extra-spinal enthesopathies at the elbow, knee, ankle and iliac crest were recorded. Osteophytes and syndesmophytes were excluded. References Julkunen H, Heinonen OP and Pyörälä K (1971) Hyperostosis of the spine in an adult population. Annals of Rheumatic Disease 30:605-612 Maat GJR, Mastwijk RW, Van der Velde E (1995) Skeletal distribution of degenerative changes invertebral osteophytosis, vertebral osteoarthritis and DISH. International Journal of Osteoarchaeology 5:289-298 Resnick D and Niwayama G (1976) Radiologic and pathologic features of spinal involvement in diffuse idiopathic skeletal hyperostosis (DISH). Radiology 119:559-568 Rogers J and Waldron T (1995) A field guide to joint disease in Archaeology. England: John Wiley & Sons Ltd. Acknowledgements The authors thank Dr. Dawnie Steadman for granting access to the WM Bass Donated Skeletal Collection and to the medical history of the individuals selected for the study Extra-spinal manif. Smooth Spicules - 1.99mm 2mm – 9.99mm >10mm Extra spinal manifestations colour code: Isolated Touching Ankylosed Spinal manifestations recording system: M A L E S F E M A L E S CONCLUSIONS Our analysis confirms the relationship between the development of DISH an age. It permitted the identification of isolated DISH-related outgrowths. No relationship has been found between the spinal and the extra-spinal manifestations. This study improved our understanding of the pathogenesis of DISH and the development of the ankylosis, however it must be noted that the early lesions identified probably have no clinical consequences.