Ankle deformity and arthritis Case for small group discussion AOTrauma—Foot & Ankle Module 7: Ankle arthritis Christina Kabbash, US

Case description 46-year-old man Right rigid cavus ankle deformity, no trauma, history of Lyme disease with arthralgia and spine involvement Builds submarines

Case description Ankle ROM: 5° Subtalar ROM: 0° No hindfoot pain after ankle injection with local anesthetic No neuropathy Nonsmoker; no diabetes Next step: infection workup

Preoperative AP/mortise x-ray Need to restore the mechanical axis with the calcaneus under the knee (lateralization) Need to correct the heel varus Need to bone graft the cysts

Preoperative lateral x-ray Need to restore the mechanical axis with the calcaneus under the knee (lateralization) Need to correct the heel varus Need to bone graft the cysts Cultures at time of surgery!!!

Infection work-up Erythrocyte sedimentation rate (ESR), C-Reactive Protein Test (CRP), Bone scan 99Tc, and 111Indium negative for osteomyelitis CT-guided bone biopsy negative for osteomyelitis CT showed bony cysts at the tibiotalar joint and moderate arthritis at the subtalar joint

Rheumatology work-up Lyme titer 1.3 (3.3 prior to IV treatment for spine involvement) Immunoglobulin (IgG and IgM) positive No contraindications for surgery

Treatment options? Bracing Fusion Total ankle replacement Bracing: rigid deformity—unable to restore mechanical axis Total ankle: significant loss of bone stock with cysts; significant varus deformity

Fusion options External fixation Screws Plates and screws Hindfoot arthrodesis nail (TTC fusion) Arthroscopic Considerations: good soft-tissue envelope present, need to be able to correct severe deformity and bone graft cysts External fixation and TCC: overkill Arthroscopic : not powerful enough

ORIF approaches Anterior Transfibular Posterior Considerations: good soft-tissue envelope present, need to be able to correct severe deformity and bone graft cysts External fixation and TCC: overkill Arthroscopic: not powerful enough

2 weeks postoperative Did not fully correct varus since the hindfoot was rigid Fibula bone graft used for cysts and for vascularized strut Hindfoot was rigid but no painful, so not fused

8 months postoperative

Preoperative 8 months postoperative Left ankle

Preoperative 8 months postoperative Left ankle

Take-home messages Always rule out infection Choose the proper surgical approach for the case considering soft-tissue envelope, bone stock, and fixation technique Advantages of transfibular approach: Excellent exposure for debridement of talar dome and even posterior subtalar joint Fibula provides morselized and live bone graft