47: Recalcitrant Ankle Arthrodesis Nonunion with Infection Treated with Antibiotic Cement-Coated Rod

Fig. 1

Pre-operative anteroposterior (a) and lateral (b) view radiographs. Note the proximal antegrade tibial rod and that the talus is eroded (Copyright 2014, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore)

Fig. 2

Pre-operative Saltzman view radiograph. Note the valgus heel and the medial ankle hypodensity in the soft tissue where the open draining wound is located (Copyright 2014, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore)

3 Preoperative Problem List

Ulcer measuring 3 cm by 4 cm that had a depth of greater than 5 cm and was able to be probed to the bone and joint
Infected ankle nonunion
Retained hardware
Deformity with excessive hindfoot valgus
Type B host: Reiter syndrome and immunosuppressive therapy

4 Treatment Strategy

The strategy was to first remove the tibial nail and foot hardware. Then the nonunion was resected through a medial transverse incision for ease of closure and to assist in correcting the ankle valgus. The transverse incision is not conventional but has healed well in our hands in these complex cases because there was no tension on the skin envelope at the time of closure. The hindfoot was stabilized using an antibiotic cement-coated intramedullary nail. We typically use PMMA bone cement with vancomycin and tobramycin powder added. The wet cement is pumped into a tube and the nail is slid in. The tubing is removed once the cement hardens. A short leg, non-weight-bearing cast was applied until radiographic evidence of bony fusion was observed.

5 Basic Principles

Septic nonunions require thorough débridement to remove all necrotic tissue. All hardware that is in close proximity to infection needs to be removed to minimize persistent infection. A local antibiotic depot and intravenous antibiotics are essential to eradicate infection. Antibiotics for systemic use can be selected based on the sensitivity pattern of the target organism. Local antibiotics must be broad spectrum unless the organism is known pre-operatively.