Hindfoot fusion procedures encompass arthrodesis of subtalar, talonavicular, and calcaneocuboid joints individually or in combination, depending on deformity severity and joint involvement. The triple arthrodesis (Ryerson 1923) fuses all three hindfoot joints and remains a powerful tool for correcting severe rigid hindfoot deformity. Isolated subtalar fusion is preferred when only the subtalar joint is symptomatic or for selective correction. Double arthrodesis (sparing one joint) is increasingly used for adult-acquired flatfoot deformity (AAFD) when calcaneocuboid joint is uninvolved.
Indications for complex hindfoot arthrodesis: severe rigid pes planovalgus (Stage IV AAFD with arthritis, Müller-Weiss disease, neurological flatfoot), severe rigid pes cavovarus (Charcot-Marie-Tooth, residual clubfoot, posttraumatic), tarsal coalition with associated arthritis or deformity, severe posttraumatic hindfoot arthritis, Charcot neuroarthropathy with hindfoot collapse, rheumatoid arthritis with deformity, and salvage of failed prior surgeries. Specific joint involvement guides procedure selection—e.g., isolated subtalar arthritis warrants subtalar fusion alone; combined subtalar and talonavicular involvement warrants double or triple arthrodesis depending on calcaneocuboid status.
Surgical technique: triple arthrodesis can be performed via single lateral incision (modern minimally invasive approach), double incision (medial + lateral), or all-medial approach (cosmetic, allows valgus correction). Cartilage is denuded, deformity corrected to neutral plantigrade alignment, and rigid fixation applied with two large cannulated screws across each joint or screw-and-plate combinations. Bone graft (autograft from iliac crest or local cancellous) supplements gaps in deformity correction. Postoperative protocol: non-weight-bearing 6-8 weeks, then partial weight-bearing in cast/boot, full weight-bearing at 12 weeks. Outcomes: 85-95% fusion rate with modern technique, 80-90% patient satisfaction, significant pain reduction; complications include nonunion (5-15%, higher with smoking, diabetes, neuropathy), malunion, infection, and adjacent joint arthritis (ankle and midfoot, accelerated due to lost motion). Long-term, ankle arthritis develops in 40-60% at 10-15 years follow-up but is often well tolerated; midfoot arthritis may require additional fusion. Salvage options for failure include revision arthrodesis with bone graft and tibiotalocalcaneal nailing for combined ankle-hindfoot involvement.