Keywords:
Extremities, Musculoskeletal bone, Professional issues, Plain radiographic studies, Education, Education and training
Authors:
L. Nelson1, P. Smalley1, J. Harris2; 1Salford/UK, 2Manchester/UK
DOI:
10.1594/essr2017/P-0198
Background
Patients with diabetes mellitus have a high incidence of bone pathology,
particularly when there are cutaneous ulcers present.
In one of the first case series of diabetic foot ulcers,
77% of patients with ulceration of the foot had multiple bone lesions,
even where there was not communication between the bone and the cutaneous ulcer and these lesions were not limited to the area of the ulcer.
1
Osteomyelitis,
an inflammatory process of infectious nature,
is an important complication causing bone lesions in such patients secondary to impaired arterial circulation,
neuropathy and entry of external microbes via the ulcer,
as there is an increased risk of amputation.
The characteristic changes in the bone on X-Ray are osteoporosis,
juxta-articular defects,
osteolysis and destruction of the bone ends,
periosteal reaction and cortical sclerosis.2 These changes are very similar to changes associated with diabetic osteopathy secondary to diabetic neuropathy,
for example irregular destruction of the metatarsal heads and bone thinning with osteoblastic reaction.
It is important to distinguish these two conditions,
as the management is entirely different.
Diabetic osteopathy requires no specific intervention,
whilst osteomyelitis is difficult to treat with antimicrobials and may result in surgical intervention.
Additionally,
it is very important to not under diagnose or over diagnose osteomyelitis.
The condition has significant morbidity and mortality,
whilst a mistaken diagnosis can result in weeks of intravenous antibiotic therapy with the potential for dangerous side effects such as C.difficile infection,
as well as the expense of such treatment. 3
Osteomyelitis is notoriously difficult to diagnose and also controversial.
The Infectious Diseases Society of North America recommends plain radiography due to the ease of acquisition of such imaging and the relative low cost.4 However early changes can be missed as they tend to appear 10-14 days after development of infection,
therefore serial radiographs at 2 weeks and 4 weeks are recommended.5 These changes must be interpreted by an experienced clinician with knowledge of the clinical context of the case.
This is because firstly,
plain radiography alone has a low sensitivity for diagnosing osteomyelitis 6 and secondly,
studies have shown diagnosis to be better when experienced clinicians with knowledge of the clinical context are involved in evaluating such patients.
7
Serial plain radiography reported by a specialist musculoskeletal radiologist as part of a Multidisciplinary Team Work-up (Diabetic Foot Clinic) is therefore currently recommended in our hospital to evaluate potential osteomyelitis development in patients who attend the diabetic foot clinic with active infection.
There are a variety of dressings available used by Tissue Viability Nurses to dress resulting wounds.
Some are infiltrated with silver for example,
which helps wound healing.
It has been noted by our radiologists that some of these dressings can obscure the X-ray appearance of the lower extremity and therefore hinder a reliable evaluation of the bone.
The aim of this poster is to provide a visual education to radiography staff and junior doctors as to which dressing types cause a problem and which do not,
by showing their appearances on X-ray in a poster format.