Range of Motion After Ankle Fusion
No, you cannot regain range of motion at the fused ankle joint itself after ankle arthrodesis, as the surgical goal is permanent bone fusion that eliminates joint movement. However, adjacent joints can compensate with increased mobility, and in rare cases, fusion takedown with conversion to total ankle replacement may restore some motion.
Understanding Ankle Fusion
Ankle arthrodesis (fusion) is a surgical procedure that permanently joins two bones to eliminate joint movement, trading mobility for pain relief and stability 1. The fundamental principle is bone-to-bone healing that creates a solid, immobile construct.
Expected Outcomes After Fusion
- Pain reduction occurs in the majority of cases, though residual symptoms may persist 2
- Walking distance typically extends (more subjectively than objectively measured) 2
- Gait pattern changes are usually slight, though walking without aids is rarely achieved 2
- Stair climbing without restrictions is not always possible 2
- Return to work is often feasible 2
Motion at Adjacent Joints
While the fused ankle joint itself has zero dorsiflexion or plantarflexion 3, the hindfoot joints (subtalar and transverse tarsal joints) can provide compensatory motion if they are not included in the fusion 4. This adjacent joint motion helps maintain some functional mobility, though it is not equivalent to normal ankle motion.
Conversion to Total Ankle Replacement
In select cases of painful, malaligned, or nonhealed ankle fusions, takedown and conversion to total ankle replacement can restore significant motion 3:
- Initial postoperative measurements after fusion takedown show average dorsiflexion of 10.9±5.93 degrees and plantarflexion of 14.1±5.22 degrees 3
- At long-term follow-up (average 4.2 years), dorsiflexion improved significantly to 15.5±6.33 degrees 3
- Patient-reported outcomes showed significant improvements in pain (VAS improved from 64.5 to 29.4) and function 3
Important Caveats for Fusion Takedown
This is not a routine procedure and should only be considered in specific circumstances:
- Patients must have ongoing pain after fusion or pain after an initial period of comfort 3
- The procedure is technically challenging due to bone defects left by the previous fusion 4
- Inflammatory joint disease patients have significantly higher nonunion rates (73% vs 96% fusion rate) if re-fusion becomes necessary 5
- Long-term durability of these converted replacements compared to primary replacements remains uncertain 3
Clinical Bottom Line
Once an ankle fusion successfully heals, the joint itself will not regain motion—this is the intended permanent result 1. Functional adaptation occurs through adjacent joint compensation 4. The only way to restore actual ankle joint motion after fusion is through the complex salvage procedure of fusion takedown and conversion to total ankle replacement, which carries significant risks and should be reserved for carefully selected patients with persistent problems 3.