Acro-osteolysis in systemic sclerosis is associated with digital ischaemia and severe calcinosis

Objectives. Acro-osteolysis (bony resorption of the terminal digital tufts) is a well-recognized, but under-researched, manifestation of SSc. Our aim was to investigate the hypothesis that acro-osteolysis is associated with (i) the severity of digital ischaemia and (ii) the presence of calcinosis. Methods. This was a retrospective study of 101 patients with SSc in whom hand radiographs taken between 2001 and May 2008 were available for review. These radiographs were graded for severity of acro-osteolysis on a 0-4-point scale for each finger (0 = normal bone structure, 4 = severe pencilling of the terminal phalanges). From these scores, patients were subdivided into the following two groups: normal/minimal acro-osteolysis and moderate/severe acro-osteolysis. The presence or absence of calcinosis (mild, moderate or severe) was also documented. Results. Of the 101 patients, 68 were grouped as normal/minimal acro-osteolysis and 33 as moderate/severe acro-osteolysis. Forty-five had severe digital ischaemia: 25 (76%) of the patients with moderate/severe acro-osteolysis compared with 20 (29%) of those with normal/minimal acro-osteolysis (multifactorial analysis: P < 0.001). Patients with moderate/severe acro-osteolysis were more likely to have severe calcinosis (33% vs 13%), but this was not statistically significant after adjustment for potential confounders. Conclusion. Acro-osteolysis was strongly associated with severe digital ischaemia. The potential association with severe calcinosis merits further study. Prospective studies are required to investigate acro-osteolysis as a marker of digital vascular disease progression and of treatment response.