Orthopaedic Surgery - Köhler Disease

Basics

Köhler disease is an osteochondrosis of the tarsal navicular bone, characterized by temporary impairment of its blood supply during childhood.

The disorder produces osteonecrosis followed by sclerosis, flattening, fragmentation, and eventual reossification of the navicular.

The typical patient is a child approximately 3–7 years of age who develops pain over the medial midfoot.

Symptoms usually increase with physical activity and improve with rest.

Despite occasionally striking radiographic abnormalities, the long-term clinical outcome is generally excellent.

Synonyms

Köhler disease may also be described as:

Osteochondrosis, osteonecrosis, or osteochondritis of the tarsal navicular.

Classification

Köhler disease belongs to the group of disorders known as osteochondroses.

These conditions involve temporary vascular disturbance of a developing ossification center.

Other disorders in this general category include:

Legg–Calvé–Perthes disease and Osgood–Schlatter disease, although their specific pathophysiology and anatomic sites differ.

Prevention

No practical preventive strategy has been established.

The disease is uncommon and generally cannot be predicted before symptoms develop.

Epidemiology

Köhler disease occurs predominantly in young children.

Sex

Boys are affected approximately 2–3 times more often than girls.

Incidence

The disease is uncommon.

Risk Factors

Reported associations include:

Male sex, high activity level, and participation in sports involving repeated running or kicking.

However, the condition may also occur in otherwise healthy children without identifiable risk factors.

Genetics

No recognized pattern of genetic transmission has been established.

Köhler disease is generally considered sporadic.

Etiology

The exact cause is not completely established, but the most widely accepted mechanism involves repetitive mechanical compression of the developing navicular with temporary compromise of its blood supply.

Navicular Development

The navicular is one of the last tarsal bones to ossify.

Its ossification center usually becomes visible at approximately 2–3 years of age.

During early development, the bone may initially ossify from several small centers that eventually merge.

Mechanical Compression

The navicular lies at the apex of the medial longitudinal arch and is positioned between the talar head proximally and the cuneiforms distally.

As the child walks, the developing navicular is subjected to substantial compressive forces.

Because the bone is relatively soft and incompletely ossified at this stage, repeated compression may compromise local vascularity.

Osteonecrosis and Healing

Temporary ischemia produces:

Bone necrosis, resorption of dead bone, sclerosis, flattening, and later reossification.

As vascularity returns, the navicular gradually remodels and resumes normal growth.

Associated Conditions

A mild association with Legg–Calvé–Perthes disease has been described in some series.

Both disorders involve temporary osteonecrosis during skeletal development, although they affect different bones.

Diagnosis

Signs and Symptoms

The characteristic presentation is:

Medial midfoot pain in a young child, aggravated by activity and relieved by rest.

Tenderness

There is usually focal tenderness directly over the tarsal navicular.

Limp

Pain during weight bearing may produce an antalgic gait.

Altered Foot Loading

Some children walk preferentially on the lateral border of the foot to reduce pressure through the medial midfoot and navicular.

Physical Examination

Inspection

Look for:

Swelling over the medial midfoot, altered gait, and avoidance of normal medial-foot loading.

Palpation

Focal tenderness over the navicular is a typical finding.

Mild surrounding soft-tissue swelling may also be present.

Gait Examination

The child may demonstrate:

A limp, shortened stance phase on the affected side, or walking along the outer border of the foot.

This compensatory pattern decreases compression through the painful navicular.

Range of Motion

Ankle and subtalar range of motion is usually relatively preserved.

Pain is primarily generated by loading or direct palpation of the navicular rather than by a primary ankle-joint disorder.

Imaging

Plain Radiographs

Plain radiographs are generally sufficient to establish the diagnosis once characteristic changes have developed.

AP, lateral, and oblique views of the foot may be obtained.

Normal Navicular Ossification

The normal navicular begins to ossify at approximately 2–3 years of age.

Multiple early ossification centers may be visible before they coalesce.

Awareness of this normal developmental appearance prevents overdiagnosis.

Radiographic Findings

Characteristic findings in Köhler disease include:

Flattening of the navicular in its anteroposterior dimension, increased sclerosis, irregularity, fragmentation, and apparent collapse.

The navicular may appear unusually dense compared with the surrounding tarsal bones.

Bilateral Disease

Radiographic abnormalities may occasionally be bilateral, although symptoms do not necessarily occur to the same degree on both sides.

MRI

MRI is usually unnecessary when plain radiographs demonstrate characteristic changes.

It may be useful when:

Clinical suspicion remains high despite normal or equivocal radiographs or when another diagnosis needs to be excluded.

MRI can demonstrate:

Abnormal bone marrow signal, edema, and changes compatible with impaired navicular perfusion.

Healing on Imaging

As the disorder resolves, radiographs show:

Progressive reossification, restoration of bone density, remodeling, and gradual recovery of navicular shape and growth.

Radiographic recovery may take considerably longer than symptomatic improvement.

Pathological Findings

Biopsy is not routinely performed and is unnecessary for diagnosis.

Historical pathologic specimens demonstrate typical features of healing osteonecrosis, including:

Areas of necrotic bone, resorption of dead trabeculae, and subsequent formation of new bone.

Differential Diagnosis

Important alternative causes of medial midfoot pain include:

Navicular fracture, accessory navicular, ankle or foot sprain, soft-tissue infection, and other occult fractures.

Navicular Fracture

A traumatic navicular fracture should be considered when there is:

A clear injury, acute severe pain, marked swelling, or a fracture line inconsistent with developmental osteochondrosis.

Accessory Navicular

An accessory navicular may also cause medial midfoot prominence and pain.

It usually occurs near the insertion of the posterior tibial tendon and has a different radiographic appearance.

Soft-Tissue Infection

Infection should be considered when pain is associated with:

Erythema, significant warmth, fever, systemic illness, or abnormal inflammatory markers.

These findings are not typical of Köhler disease.

Treatment

General Principles

Treatment is primarily symptomatic because Köhler disease is a self-limited condition.

Management depends on symptom severity.

Options include:

Rest, activity modification, arch support, analgesia, and temporary immobilization.

Mild Symptoms

Children with minimal discomfort may need only:

Reduction of strenuous activity and use of a supportive shoe or medial arch support.

Moderate to Severe Symptoms

More symptomatic children may benefit from a:

Below-knee walking cast with appropriate arch molding for approximately 4–8 weeks.

Immobilization can substantially reduce pain and may shorten the symptomatic period.

Weight Bearing

Most children can bear weight according to comfort.

If symptoms are particularly severe, temporary non-weight bearing or protected weight bearing may be appropriate.

After Cast Removal

Once tenderness has largely resolved, treatment can transition to:

Arch support, supportive footwear, and gradual return to normal activities.

Return should be guided by the clinical examination rather than persistent radiographic abnormalities.

Activity Modification

Activities that reproduce pain should temporarily be avoided.

These commonly include:

Running, jumping, kicking, and high-impact sports.

Return to Sport

After pain and focal tenderness resolve, activity can be increased gradually.

An arch support may be used during the transition back to sports.

Physical Therapy

Formal physical therapy is generally unnecessary.

Activity can usually be advanced by the parents according to the child’s symptoms and physician guidance.

Medication

Analgesics may be used when required.

Appropriate options include:

Acetaminophen or NSAIDs.

Medication is used for symptom relief rather than to alter the natural history of the disorder.

Surgery

Surgery is almost never necessary in childhood.

Because spontaneous healing and remodeling are expected, operative treatment should not be performed simply because the navicular appears abnormal on radiographs.

Persistent Adult Symptoms

Very rarely, residual painful degeneration persists after skeletal maturity.

In severe refractory cases, a salvage procedure such as talonavicular fusion has historically been used.

Follow-Up

Prognosis

The prognosis is excellent.

Symptoms typically resolve as the navicular revascularizes and remodels.

Radiographic Recovery

Within approximately 2–3 years, the navicular usually regains a near-normal radiographic appearance.

Clinical symptoms typically resolve considerably earlier.

Complications

Complications are uncommon.

Rarely, patients may continue to have:

Residual aching, medial midfoot tenderness, or activity-related discomfort.

These symptoms are usually treated conservatively with:

Activity modification, rest, supportive footwear, or arch support.

Patient Monitoring

Follow-up should be guided mainly by the child’s clinical recovery rather than serial radiographic appearance.

Important findings to monitor include:

Navicular tenderness, limp, activity-related pain, and ability to resume normal walking and sports.

Repeated radiographs are usually unnecessary once the diagnosis is established and the child is improving clinically.

Persistent pain, worsening symptoms, or failure to follow the expected benign course should prompt reconsideration of alternative diagnoses such as fracture, accessory navicular, infection, or another structural foot disorder.