Mueller-Weiss Treated With Limited Fusion

Indications

Advanced stage of Mueller-Weiss syndrome ( Fig. 25.1 ) with
- Symptomatic osteoarthritis
- Progressive destabilization of the foot
Secondary peritalar and midfoot pain due to tarsal destabilization
Loss of neutral foot position that cannot be compensated by shoe modifications

Indications Pitfalls

Indications Controversies

Crucial for success, e.g., to obtain a plantigrade and stable foot, are
- Appropriate positioning of the talus on top of the calcaneus, thereby correcting a hindfoot varus position
- Restoring talonavicular alignment in the sagittal and horizontal planes, thereby achieving realignment of the naviculo-cuneiform and tarsometatarsal joints
In most instances, this can be achieved with isolated talonavicular fusion

Careful and thorough assessment of history and complaints, in particular
- Disability in daily activities and sports
- Impairment by pain
- Effect of previous conservative measures
Careful clinical assessment of
- Hindfoot alignment when standing (posterior view; Fig. 25.2A )
- Ankle, midfoot, and forefoot alignment (anterior view; Fig. 25.2B )
- Painful pseudo-exostosis over the dorsolateral Chopart joint
- Ankle and subtalar range of motion with the patient sitting
- Ankle stability with the patient sitting and hanging feet
- Pain using a visual analog scale of 0–10 points
Pain is typically located over the lateral navicular bone (pseudo-exostosis)
Peritalar motion is typically
- Restricted for eversion/pronation
- Preserved for inversion/supination

Bilateral plain weight-bearing radiographs, including anteroposterior views of the foot and ankle, lateral view of the foot, and alignment view, should be used to rule out
- Articular configuration and integrity of the subtalar and talonavicular joints
- Collapse of the lateral navicular and tilt of the navicular toward medial ( Fig. 25.3 )
- Angular deviation of talus in all horizontal planes (e.g., exorotation)
- Presence of arthritic changes at the ankle and subtalar joint
Computed tomography scans, if possible while weight bearing, are initiated to
- Assess articular configuration of the ankle, subtalar, and talonavicular joints
- Assess collapse, osteoarthritic changes, and fragmentation of the lateral talonavicular joint
- Detect other bony abnormalities ( Fig. 25.4 )
Magnetic resonance imaging can be used to
- Determine the activity of avascular necrosis of the lateral navicular, for example, presence and extent of perifocal edema
- Assess surrounding soft tissues
Single-photon emission computed tomography with superimposed bone scan may be used to visualize
- Morphologic pathologies and associated activity process ( Fig. 25.5 )