Current Concepts With External Fixation And The Charcot Foot
When Patients Have Isolated Rearfoot And Ankle Deformities
In patients with isolated diabetic Charcot neuroarthropathy rearfoot/ankle deformities, surgeons may perform a single or multiple joint arthrodesis procedures depending on the location, associated soft tissue or osseous infection and severity of deformity. These clinical case scenarios are more complex and early intervention based on their inherent instability might be necessary to prevent further skeletal architecture collapse with subsequent ulceration, infection and/or lower extremity amputation.
Surgical procedures for this category of patients may include and are not limited to isolated ankle, subtalar, triple, tibiotalocalcaneal or pantalar arthrodesis in order to provide solid union across single or multiple joints. In clinical case scenarios with a severe diabetic Charcot neuroarthropathy talus dislocation, a single or staged talectomy with tibiocalcaneal or tibiocalcaneonavicular arthrodesis may be necessary to correct the deformity. As we discussed previously with the diabetic Charcot neuroarthropathy midfoot deformities, rigid internal fixation in the form of screws, locking plating and/or intramedullary fixation plays a crucial role in providing osseous union across the arthrodesis site(s). Careful consideration is necessary for the use of internal fixation in the presence of non-infected wound(s) while external fixation may become ideal in cases of previously resected osteomyelitic joints and eradicated soft tissue infections.
The use of cemented non-biodegradable antibiotic spacers or antibiotic-coated nails is also beneficial for largely resected osseous defects of the diabetic Charcot neuroarthropathy rearfoot/ankle and before the definitive surgical procedure.19,20 Adjunctive therapies and/or procedures for the diabetic Charcot arthropathy midfoot and/or rearfoot/ankle may include the utilization of autogenous or allogenic bone grafting; bone growth stimulation; equinus correction; and/or skeletal stabilization of joints distal and proximal to the arthrodesis site(s).
Essential Considerations With External Fixation
General indications of external fixation use for the foot and ankle include and are not limited to unstable and/or non-braceable Charcot neuroarthropathy deformities; malunions; nonunions; deformities with associated soft tissue and osseous defects; a previous history of osteomyelitis or septic joint; and salvage of failed internal fixation. These clinical scenarios are often associated with poor bone stock, retained and/or broken hardware, severe deformity, residual infection and wound healing complications. In certain cases, surgeons can supplement the use of internal fixation with external fixation to enhance osseous stability and healing. The requirements for combined internal fixation with external fixation are adequate soft tissue coverage, bone quality amenable to fixation and an absence of infection.