Diabetic Osteopathy

Abstract

Radiographically detectable abnormalities in the feet of diabetic patients are more common than is generally recognized. These changes are often characteristic enough to indicate a diabetic cause of the “foot trouble.” The purpose of this report is to analyze these changes and to present the roentgen features which may lead to a diagnosis of a “diabetic foot.” Our observations on this subject derive from a clinical and radiological survey of 242 patients from the Diabetic Clinic, Ben Taub General Hospital, Houston, Texas. These included approximately 50 per cent of all outpatients seen in the Clinic from October through December 1964, selected at random. In addition, we have studied the films of the feet of over 20 selected diabetic patients hospitalized because of “foot trouble.” The radiographic examinations consisted of postero-anterior and oblique views of the feet. No specialized technics, such as magnification or arteriography, were used. Twenty-seven per cent of these ambulatory patients had radiographically detectable foot changes related to diabetes (TABLE I), and 6.8 per cent had bone abnormalities classified as “diabetic osteopathy.” Osteoporosis of the bones of the feet may be diffuse or localized and occurs independently of disuse (Fig. 1). It may be the only bone manifestation of the osteopathy. Juxta-artieular cortical bone defects, usually 1 to 5 mm in diameter and sharply outlined, occur principally in the phalanges (often in the big toe) and sometimes in the heads of the metatarsals (Fig. 2). These changes are not always easy to recognize; radiographs in more than one projection may be needed for demonstration of the defects. Magnification technic has been advised for demonstration of these small changes (1). The small cortical defects may remain unchanged for a long time or may progress to osteolysis. Two patients showed no change in this type of osteopathy over a one-year follow-up. One patient with juxta-articular defects in phalanges had rapid, extensive destruction of all phalanges and metatarsals within seven weeks of the initial examination (Fig. 3). Osteolysis of the ends of bones is most common in the distal metatarsals and the proximal phalanges. Typically, it starts at the metaphysis as an ill-defined loss of cortex (Fig. 4, A & B), extends through the subarticular bone, and eventually destroys the entire bone end but spares the central part of the diaphysis (Fig. 4, C). The end of the shaft is at first ragged; eventually it becomes tapered and increased in density, resulting in pencil-like or candlestick deformity (Fig. 4, D). These terms are accurately descriptive. The surface of the remaining bone is sclerotic and either smoothly tapered like a pencil or uneven like the end of a candle in which the wax has remained high around part of the edge as it burned.