Valgus Stress Radiography as a Criterion for Total Ankle Arthroplasty Without Medial Malleolar Osteotomy: A Report of Three Severe Varus Cases

Total ankle arthroplasty (TAA) is performed for ankle arthritis; however, in cases with severe varus deformity, malalignment of implant positioning, and early loosening can be problematic. Medial malleolar osteotomy is often performed in such cases to facilitate proper implant positioning, but it carries risks including nonunion and delayed rehabilitation. This study reports three cases of TAA for severe varus ankle deformity (preoperative talar tilt >15°) performed without medial malleolar osteotomy, using preoperative valgus stress radiography as the selection criterion. Based on our clinical experience, we hypothesized that in cases where varus deformity can be corrected (talar tilt ≤10°) under valgus stress (a provisional threshold defined empirically), acceptable short-term outcomes might be achieved without osteotomy. Accordingly, three elderly women (aged 73-78 years; one with rheumatoid arthritis, two with osteoarthritis) meeting this criterion underwent TAA and were followed for one year. Standard rehabilitation was initiated in all but one case, requiring a tailored rehabilitation program due to concomitant surgery. Minor complications included two suspected or nondisplaced medial malleolar fractures, both healing without medical intervention or unloading. At final follow-up, all patients achieved pain relief, improved mobility, and satisfactory radiographic alignment without implant loosening. Preoperative valgus stress radiography may assist in identifying selected patients who can undergo TAA without medial malleolar osteotomy. However, the high incidence of medial malleolar fracture in this small cohort indicates that the provisional 10° cutoff should be interpreted with caution and may not be sufficiently conservative. Larger studies are needed to determine a safer and more appropriate threshold for omitting medial malleolar osteotomy.