From: Ron Hoggan

Nonetheless, there is also a clear relationship between celiac disease and
many cases of seronegative arthritis, as in two of the ten patients
presented in:

Young, et. al. "Celiac Disease and Arthropathy: Case Report and 
Literature Review" _The Guthrie Journal_1993; 62(3):99-104

There is a very recent article implicating gluten intolerance in 
sacroilitis, which my source cannot, at the moment, find.

Then there is the case of seronegative monoarthritis reported here:
Borg, et. al. "Persistent monoarthritis and occult celiac disease" 
_Postgrad Med_ 1994; 70: 51-53.  

Then if we want to look at degenerative bone disease, it is associated 
with celiac disease in myriad studies. To cite a few:

Marsh "Bone Disease and Gluten Sensitivity: Time to Act, to Treat, and to 
prevent" _The American Journal of Gastroenterology_ 1994; 89(12): 2105-7

Sario, et. al. "Osteonecrosis of the femoral head in refractory celiac 
disease" _Journal of Internal Medicine_ 1994; 235: 185-9

There are even a number of reports of defects in teeth, and a high 
incidence of elevated anti-gliadin antibodies in osteoporosis. The faulty 
calcium metabolism associated with celiac disease appears to be the most 
common suggestion for a possible etiology.