A case of septic Charcot Neuro-osteoarthropathy
A 57 year old male, type 2 diabetic for 10 years, presented to our diabetic foot clinic on a Tuesday evening.
Treatment at our setting is organized in an interdisciplinary structure including diabetologists, vascular surgeons, interventional radiologists and „wound-surgeons“.
At presentation the patient was afebrile and felt unimpaired. After taking off his shoes, there was clinical evidence of a bilateral deformity consistent with a Charcot foot, together with a chronic lymphedema and toenail mycosis. The right foot appeared unaffected, while the left leg showed painless swelling up to the knee joint with warming and redness.
On the lateral aspect of the foot in projection on the base the 5th Metatarsale, there was a secreting necrosis with a diameter of 3 cm accompanied by an incipient livid discoloration of the fifth toe. In addition there was a apparently superficial lesion located on the Malleolus lateralis, marked callosities in the heel area and a tip necrosis on the first toe. Most impressive was a pronounced midfoot instability and a phlegmonous infec’tion ascending along the tendon of the M. tibialis anterior with subcutaneous fluctuation (fig 1, a-d).
Relevant impairment of the arterial perfusion was excluded using a duplex scan. In the laboratory we found leukocytosis, hyperglycaemia and signs of septicaemia.
As yet in the out-patient clinic we resected the necrosis and explored the wound cavity. All tarsal bones and the Talus were separated from their ligamental structures and located unconnected within the abscess formation. They could be removed via the lateral opening of the wound. Using an additional incision in the frontside of the lower leg, the tendon of the M. tibialis anterior was removed (fig 2, e). Following drainage and rinsing, an open-grained polyurethane foam soaked with Octenidin was inserted (fig 2, f). Immobilisation was ensued in a circular, semirigid cast. No anaethesia was necessary for these surgical procedures due to pronounced polyneuropathy!
Obtained bony material was investigated microbiologically and histologically.
Systemic antibiotic therapy was initiated with Piperacillin/Tazobactam and adapted to Amoxicillin/Clavulanic acid according to the resistogramm (Streptococcus group B, Streptococcus dysgalactiae equisimulans, Staphylococcus haemolyticus in bone biopsy).
Bony structures of the tarsal region and the Talus were completely destroyed (fig 2, g). After 14 days of wound conditioning and repeated renewing of the circular cast, a surgical reconstruction with calcaneo-tibial and metatarso-calceneal fusion was established using a circular external fixation (fig 2, h), which was removed after 5 weeks. For further wound conditioning, NPWT was continued and immobilization ensured by using a rigid TCC (fig 3, i). With nearly complete wound closure, the patient was provided with a bivalved orthosis, which allowed demission form inpatient hospital care after 58 days (fig 3, k). Dressing changes were performed on alternate days by a qualified mobile nursing service. The bivalved orthosis was worn until accommodation with custom made shoes combined with an in-shoe orthosis was established in the 9th month. At that time there was a stable Calcaneo-tibial fusion and a tense pseudarthrosis in the Metatarso-calcaneal transition (fig 3, j) with the foot in plantigrade position (fig 4, l-m).
With this care the patient is capable to work again and also increasingly pursuing his hobby of hunting in uneven terrain.
Management of patients with infected Charcot feet as a distinct complication requires specialized and well coordinated transsectoral and interdisciplinary structures, aiming at early intervention according to the criteria of septic surgery. Despite substantial tissue loss in some cases due to consequent removal of germ loaded structures with the goal of reducing bioburden, very often functional limbs can be preserved.
Gerald Engels, MD
General Surgeon, Wound-Surgeon, Foot and Ankle Surgeon
St. Vinzenz Hospital, Cologne
Private Practice Surgery, Bayenthalgürtel, Cologne, Germany
Stephan Morbach, MD
Diabetologist and Angiologist
Marienkrankenhaus, Soest, Germany