No abstract

Cauterisation with silver nitrate is commonly used to treat overgranulation. Silver nitrate has a high density and a high mass attenuation coefficient, and it is therefore highly radio-opaque. We present a case in which its topical application to an area of overgranulation was interpreted as a bony fragment by the reporting radiologist in a patient with a supracondylar humeral fracture whose radiograph after removal of K-wires showed a large radio-opaque lesion. Although not a new phenomenon, it is one not widely known, and it can lead to confusion and unnecessary further imaging. KEYWORDSSilver nitrate -Radio-opacity -Overgranulation Case HistoryWe report the case of a three-year-old girl who sustained a supracondylar humeral fracture. This was treated with closed reduction and K-wire fixation. The fracture healed well and the K-wires were removed under nitrous oxide and oxygen three weeks following the injury. On removal of the wires, considerable overgranulation tissue was noted on the medial side of the elbow, which was treated with silver nitrate.Plain radiograph of the elbow following the procedure demonstrated a 15mm  10mm radio-opaque lesion on the medial side of the elbow (Fig 1), which was interpreted by the reporting radiologists to be 'a large detached bony fragment lying in the cubital fossa'. This diagnostic misinterpretation was noticed in clinic at a follow-up visit by the treating orthopaedic surgeon and reported back to the radiology department. The history of silver nitrate application had not been documented on the radiograph request form. However, previous films were available for comparison. DiscussionThe formation of granulation tissue is a necessary part of the proliferative phase of wound healing. Dermal fibroblasts increase in number and synthesise a network of protein fibrils. Local tissue hypoxia promotes angiogenesis and this protein framework is infiltrated by capillary buds. In normal wound healing, epidermal keratinocytes proliferate at the margins of the wound before migrating across the newly formed granulation tissue. These keratinocytes form an epithelial membrane and the wound is sealed. Occasionally, the proliferative phase is excessive and granulation tissue is formed well above the height of surrounding healthy tissue. This is described as 'overgranulation'. The cause of this exuberance is not well understood but it may represent an aberrant response to a persistent inflammatory stimulus.When overgranulation occurs it impedes epithelialisation and delays wound healing. Various methods have been described to treat overgranulation including topical steroids, steroid impregnated tape and cauterisation with silver nitrate. Silver nitrate inhibits fibroblast proliferation and usually leads to a rapid resolution of the overgranulation.The mass attenuation coefficient is a standardised measure of attenuation of materials independent of their physical state. This coefficient, however, is dependent on the energy of incident radiation due to K shell effects (assumed to be ...

No abstract

No abstract

No abstract