Hip septic arthritis diagnosed during rehabilitation of a trans-tibial amputation due to a diabetic foot ulcer : a case report
Mr Alexis HOMSa, Prof Arnaud DUPEYRONa
a CHU Nimes Carémeau
A major part of lower limb amputations concerns patients with diabetes, and is related to the appearance of a diabetic foot ulcer, that can cause serious complications if it becomes septic.
A 64 years-old woman with diabetes mellitus, socially isolated, is hospitalized, being in a hyperosmolar coma ; her diabetes was decompensated by a toxic shock due to a necrotic diabetic foot ulcer, requiring right trans-tibial amputation.
Then she was admitted to a rehabilitation unit, where she was suffering from increasing left hip pains (strongly limiting her capacity to walk), in a clinical and biological inflammatory context, that led us to make a MRI.
A liquid collection into left ilio-psoas muscle associated to a rapidly destructive left hip arthritis were diagnosed. PET-scan was in favour of a septic arthritis.
Surgery enabled to make biological samples (finding a Bacteroides fragilis and meticillin-resistant Staphylococcus aureus infection), and a to implant a hip spacer, pending a hip prosthetic replacement.
The most likely etiologic diagnosis - although not certain - seems to be an infected psoas hematoma (the first hip pains she notified were accompanied by a slight hemolysis), that caused septic hip arthritis by spreading by contiguity.
Among anaerobic hip infections, Gram-positive cocci are most frequently found in patients having been treated by surgery (such as arthroplasties), whereas Gram-negative bacterias are more related to debilitated patients who had not had any hip surgical treatment1.
In case of diabetic foot ulcer infection, we should always think about the risk of a systemic infectious complications. Atypical left hip pains can be the only symptom of an infected psoas hematoma in debilitated patients as described in this observation.
1 Fitzgerald RH Jr, Rosenblatt JE, Tenney JH, Bourgault AM. Anaerobic septic arthritis. Clin Orthop Relat Res. 1982 Apr;(164):141-8.
Keywords : infection ; hip ; diabetes ; trans-tibial ; amputation ; psoas hematoma ; hip spacer ; Bacteroides fragilis