A 58-year-old female patient with a history of chronic right midfoot and hindfoot pain. Swelling and tenderness over dorso-medial aspect of the midfoot and hindfoot varus with a low medial longitudinal arch.
Paradoxical pes planus varus with prominent calcaneus posterior.
No history of trauma or history suggestive of inflammatory arthritis.
The dorsoplantar weight-bearing shows the talar heads pointing towards the second and third metatarsals instead of the first metatarsal, with compression of the lateral half of the navicular. The navicular turns into a comma-shaped bone with an internal rotation of the medial half of the bone, with degenerative perinavicular changes.
The lateral weight-bearing shows the loss of divergency between talus and calcaneus with a tendency of both to end up parallel, leaving a wider sinus tarsi. The subtalar joint projects orthogonally indicating the underlying subtalar varus (paradoxical pes planovarus). The lateral half of the navicular is compressed, with fragmentation and dorsal extrusion in the right foot. Similar findings, although less severe, in the left foot.
CT allows more adequate visualization of joints and the comma shape of the navicular and the degenerative changes at talonavicular and naviculocuneiform joints.
MRI allows the identification of oedema, chondral defects and involvement of Lisfranc and calcaneocuboid joints.
Müller-Weiss Disease (MWD) is a complex idiopathic foot condition, presenting as a chronic mid and hind foot pain and with deformity of the tarsal navicular in adults. To this date, aetiology of the MWD has remained controversial. [1]
MWD is not a condition commonly encountered neither by orthopedic surgeons nor radiologists, so it is frequently under- or misdiagnosed and un- or maltreated.
Most patients developed insidious pain in the fourth or fifth decade. Women are more commonly affected than men.
Usually both feet are affected with asymmetrical distribution.
Maceira [1] divides radiographic changes in MWD into 5 stages according to the degree of deformity of the navicular bone as referred to the Meary-Tomeno (M-T) angle (crossing of the talar axis and the first metatarsal axis) in the lateral weight-bearing view of the foot.
Progression among the 5 stages begins in childhood and ends up with the end of the ossification process. Later in life, arthritic changes can worsen the radiographic appearance of the navicular bone.
Stage 1: Minimal or no changes on radiographs. MRI show intra-osseous oedema. There may be a subtle subtalar varus deformity.
Stage 2: Dorsal angulation of M-T line. The talar head appears dorsally subluxed.
Stage 3: Compression or splitting of talonavicular, low longitudinal arch, reduction of space between the talar head and the cuneiforms. Hindfoot varus. M-T alignment is neutral.
Stage 4: Rearfoot equines, paradoxical planovarus foot. M-T line intersect on the plantar side.
Stage 5: Formation of talocuneiform articulation, complete extrusion of navicular. The use of foot orthosis may effectively decrease pain and improve function. Physical therapy can also reduce the need for medication.
Surgical treatment may be indicated when severe pain dysfunction persists in spite of the correct orthotic and rehabilitation treatment, rather than severity of the deformity. [1, 2]
There is not "gold standard" procedure. Multiple surgical techniques have been used: pinning of the navicular, excision of the dorsal extruded fragment, talonavicular arthrodesis, naviculocuneiform arthrodesis, talonaviculocuneiform fusion, etc. [3]
On the basis of the current available knowledge, in advanced stages (stages 3 and 4 of Maceira classification) talonavicular cuneiform arthrodesis, with or without hindfoot correction is a better surgical option. [4]
Müller-Weiss syndrome
1. The patient’s right foot X-ray, CT, and MRI sequences show:
- Deformity of the navicular bone at the talonavicular joint, presenting a certain degree of collapse or irregular shape, accompanied by a notably lowered longitudinal arch and hindfoot varus deformity (“paradoxical” flatfoot with varus).
- CT 3D reconstruction reveals a protruding medial border of the navicular bone, partial wear or asymmetry of the articular surfaces, and narrowing of adjacent joint spaces.
- MRI demonstrates local signal changes within the navicular bone, suggesting possible osseous stress changes or ischemic alterations.
- Prominent posterior calcaneus on the hindfoot.
- No obvious soft tissue swelling, but chronic inflammatory changes can be seen in the medial midfoot and hindfoot.
Based on the above radiological features and the patient’s history of chronic foot pain, the following differential diagnoses can be considered:
Taking into account the patient’s age, gender (MWD is more common in females), chronic pain symptoms, and the radiological findings (navicular collapse, lowered foot arch, hindfoot varus deformity, etc.), the most likely diagnosis is:
Müller-Weiss Disease (MWD).
If there is still uncertainty, other diagnostic tools (e.g., advanced MRI sequences or triple-phase bone scans) may be used to exclude other pathologies, but current evidence strongly supports this diagnosis.
Given the chronic course and structural changes of this condition, the treatment objectives are to relieve pain, stabilize the joints, and correct or slow the progression of deformities. Both conservative and surgical approaches are available.
Rehabilitation and Exercise Prescription (FITT-VP principle):
Throughout the rehabilitation process, close attention should be paid to changes in foot pain and ankle range of motion. In cases of osteoporosis or other comorbidities, training should be performed under professional guidance, gradually progressed for safety and effectiveness.
This report is based on the current radiologic and clinical information available and is for reference only. It does not replace an in-person consultation or professional doctor’s diagnosis and treatment recommendations. Specific treatment plans must be decided by a specialist, considering the patient’s circumstances and other medical examination results.
Müller-Weiss syndrome
