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Ankle Replacement: How Much Can It Correct?
Beat Hintermann, MD
Orthopaedic Clinic
(Liestal, Switzerland)
Valgus osteoarthritis of the ankle is often associated with extended destabilization of the hindfoot with
collapse of the longitudinal arch, as the case for the PTT dysfunction stage IV. While little bone is
resected, total ankle replacement will function as a spacer to tension the stretched out collateral
ligaments, thereby correcting the valgus position of talus to neutral. In most instances, additional
procedures are mandatory to get a stable and well balanced ankle joint complex, however. Total ankle
replacement in a valgus ankle will fail if not all associated problems are properly addressed. This is
particularly true in the valgus ankle with flatfoot.
Technical Solutions
1. Ankle prosthesis
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Should provide intrinsic stability in the coronal plane
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Must tighten the stretched-out ligaments
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Tools: minimal bone resection, use of an ankle that provides coronal plane stability (e.g. flat and
parallel articulating surface to second interface)
2. Valgus hindfoot misalignment
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Must be corrected to neutral, or better, slightly to varus
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Tool: medial sliding osteotomy of calcaneus
3. Instability of tibiofibular syndesmosis
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Must be stabilized
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Tool: tibiofibular fusion
4. Peritalar instability
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Must be stabilized and resulting deformity must be fully corrected, in particular in the coronal
plane
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Tool: diple fusion (talocalcaneal and talonavicular fusion)
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5. Instability of first ray / break-down of medial arch / forefoot supinatus
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Must be stabilized and fully corrected to achieve a strong medial support
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Tool: naviculo-cuneiform I-III or tarsometatarsal I fusion (depending on location of break-down)
6. Instability of medial ankle ligaments
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The anterior superficial layers should be reconstructed
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Tools: ligament reconstruction
7. Instability of lateral ankle ligaments
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Are often also incompetent; if yes, they should also be reconstructed
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Tool: lateral ligament reconstruction
8. Disorders of peroneal tendons
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Can be contract (e.g. in fixed flatfoot deformities), or incompetent (e.g. in a highly unstable
hindfoot)
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Tool: if contracture, tenotomy; if incompetent/dislocated, reconstruction or tendon transfer
Limitations of Procedure
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Not manageable correction of deformity
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Not manageable stabilization of hindfoot and medial arch
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Gap of >12mm at medial tibiotalar joint (e.g. talar tilt >15°)
Contraindications
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Charcot neuroarthropathy
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Neurologic disorder
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