Bone histomorphology may be unremarkable in diabetes mellitus

Histomorphological studies on bone in human diabetes mellitus are scarce. The aim of this study was to observe the histomorphological appearance of bone in amputation specimens from feet of patients with diabetes mellitus.

Routine histopathology reports on 45 amputation specimens were evaluated, provided the osteotomy was located in unaffected bone tissue. The bone morphology of regions affected with gangrene and/or osteomyelitis was considered, as well as the morphology at the dissection margin at a distance from the affected parts. The specimens were obtained from 43 diabetic patients, most of whom exhibiting the so-called neuroischemic diabetic foot with infection. The patients' age ranged from 50 to 92 years, duration of diabetes from 0 to 52 years; polyneuropathy was present in 36, peripheral ischemic vessel disease (PIVD) in 30, and renal failure in 24 of them, respectively.

There were 22 clinical cases of osteomyelitis, 20 cases of gangrene (including three cases of necrosis without surrounding inflammation), and three cases of pressure ulcer, which were treated by amputation of 24 toes, and resection of 21 metatarsal bones, respectively. Histomorphology showed osteomyelitis (n=29), bone necrosis (n=1), myelofibrosis (n = 8), and normal bone (n=7) at the affected sites, compared to normal bone (n=26), myelofibrosis (n=12), and osteoporosis (n=7) at the osteotomy sites. In cases of clinical gangrene, bones were also affected by osteomyelitis, but less so than in cases of clinical osteomyelitis (8/18 vs. 22/22; p<0.001). Bone tissue at the osteotomy sites was normal--with some myelofibrosis--in both conditions.

This pilot study shows that histomorphology of unaffected foot bone is mostly not abnormal in diabetic patients with neuropathy and PIVD. Further study is necessary to corroborate this preliminary evidence of absence of a "diabetic osteopathy" in the diabetic foot.