Osteonecrosis of the foot

What does osteonecrosis of the foot mean?

Osteonecrosis describes the death of bone cells, usually due to insufficient blood supply. In the foot, this can progress gradually or begin after an injury. If left untreated, there is a risk of structural collapse (collapse) of the bone surface, subsequent deformations and painful arthrosis of the affected joints.

• Talus (ankle bone): Risk after ankle fractures or dislocations
• Os naviculare: in adults (Müller-Weiss disease) or in children (Köhler I disease)
• Heads of the metatarsals: v. a. II–III (Freiberg disease/Köhler II)
• Sesamoid bones under the metatarsophalangeal joint of the big toe: rare, v. a. in case of overload

The consequences range from stress-related pain and swelling to changes in gait and restricted mobility. The earlier the diagnosis is made, the better the chances of slowing progression.

Anatomy & Circulation: Why the foot is at risk

The foot supports several times the body weight with every step. At the same time, the blood supply to some bone sections is relatively poor. The talus, for example, is largely covered by cartilage and has only a few vessels - after injuries, care can become critical. The navicular bone also has zones with lower vascular density, which in combination with incorrect statics or overload increases the risk of osteonecrosis.

• Talus: complex, partly endarterial supply; Risk after neck fracture
• Os naviculare: central hypovascular zone; at risk in adults with incorrect statics
• Metatarsal heads: repeated microtrauma and load peaks in the forefoot area

Causes and risk factors

Often several factors work together. A distinction is made between post-traumatic osteonecrosis (after bone fractures or dislocations) and atraumatic forms (without previous trauma).

• Trauma: ankle fractures (especially talar neck), Lisfranc injuries, forefoot fractures
• Medication: long-term or high-dose systemic cortisone therapy (risk assessment by treating physicians)
• Alcohol consumption, smoking/nicotine
• Metabolic and blood diseases: lipid metabolism disorders, sickle cell anemia, coagulation disorders
• Autoimmune diseases (e.g. lupus), organ transplant
• Radiation, chemotherapy, diving sickness (decompression)
• Chronic overload and incorrect statics in the forefoot or rear foot (e.g. hollow foot, forefoot overload)
• Idiopathic (without a clear cause), e.g. B. Müller-Weiss disease of the navicular bone in adults

Typical symptoms

• Stress-dependent pain in the affected bone/joint, later possibly pain at rest
• Tenderness, swelling, occasionally overheating
• Pain location depending on the area: ankle joint (talus), middle of foot (navicular), forefoot/head II–III
• Limited mobility, limping, reduced resilience in everyday life and sports

Warning signs after an accident: increasing, severe pain that does not subside even with rest, new misalignments or massive limping - please seek medical advice as soon as possible.

Diagnostics: This is how we proceed

In our orthopedic practice at Dorotheenstrasse 48, 22301 Hamburg, the evaluation begins with a targeted anamnesis (including previous illnesses, medications, accidents) and a physical examination with functional and stress tests.

• X-ray: initial basic diagnostics; however, early stages may be subtle
• MRI: most sensitive detection of bone marrow edema and impaired vitality; important for early diagnosis
• CT: detailed assessment of bone structure, collapse and surgical planning
• Rarely scintigraphy: functional diagnostics of blood flow if MRI/CT are inconclusive
• Laboratory: depending on the question (e.g. inflammation, coagulation, vitamin D, metabolism)

Differential diagnoses include stress fractures, osteochondral lesions (especially talus), arthrosis, inflammatory rheumatic diseases, infections and, rarely, tumors. Imaging helps to define these safely.

Conservative treatment: Start by being gentle on the joints and bones

Conservative measures are initially in the foreground - especially in early stages without collapse. The aim is to reduce pain, relieve pressure on the affected area and prevent progression.

• Relief/immobilization: temporary partial weight-bearing with forearm crutches, walker splint or stable immobilization according to individual recommendations
• Shoe and insole care: soft insoles, shaft guide, forefoot/rocker soles for pressure redistribution
• Physiotherapy: gait training, measured load build-up, mobilization of adjacent joints, strengthening of the foot and lower leg muscles
• Pain therapy: e.g. B. Paracetamol or NSAIDs in a coordinated dose and duration; Consider stomach/kidney risks
• Address risk factors: smoking cessation, alcohol reduction, optimization of blood sugar and lipids; Only adjust cortisone doses in consultation with the prescribing specialist
• Provision of orthoses/insoles in sports and work for long-term load control

Medical bone-specific therapies such as bisphosphonates are sometimes discussed, but the evidence for osteonecrosis of the foot is limited. Such therapy is only possible – if at all – after careful risk-benefit assessment and interdisciplinary coordination. An adequate supply of vitamin D and calcium is checked and supplemented if necessary.

Measures that promote regeneration (e.g. shock wave therapy or orthobiological injections) are considered in individual cases. To date, only limited data are available for osteonecrosis of the foot; Information about benefits, limits and alternatives is mandatory.

Interventional and surgical procedures: indication with a sense of proportion

If symptoms persist despite consistent conservative therapy, imaging shows progression or there is already a threat of structural collapse, joint-preserving or stabilizing interventions may make sense. The choice of procedure depends on the bone, stage and accompanying factors.

• Core decompression/retrograde drilling: relief and stimulation of bone healing in early stages; sometimes combined with spongiosaplasty
• Bone filling/grafting: non-vascularized or microvascularized bone transfers for defects
• Corrective osteotomies: Axis/load shift to reduce pressure on the necrotic area (selected cases)
• Arthroscopic measures: debridement, smoothing of unstable cartilage-bone zones in suitable locations
• Arthrodeses (joint stiffening): in advanced destruction and osteoarthritis to reduce pain and restore stability (e.g. naviculocuneiform, subtalar, ankle joint)
• Prosthetic treatment: should be examined with caution in the case of the ankle after osteonecrosis; strict indications

Orthobiological supplements such as bone marrow concentrate (BMAC) or PRP are used in combination with drilling/cancellous bone grafting in some centers. The data situation is heterogeneous. Individual information about potential benefits, missing long-term data and alternatives is essential.

After operations, phase-adapted follow-up treatment, protective loads and close follow-up checks are crucial for the result.

Special forms of osteonecrosis of the foot

• Talus osteonecrosis (ankle bone): often after fractures/dislocations. Early stages conservative/relieving, possibly retrograde drilling; in the event of collapse, solutions close to the arthrodesis.
• Müller-Weiss disease (navicular bone, adult): metatarsal pain, incorrect statics. Therapy from insoles and shoe modification to joint-preserving/arthrodesis procedures.
• Köhler's disease I (navicular, child): usually self-limiting. Protection, relief, deposits; Prognosis is often good over time.
• Freiberg disease/Köhler II (metatarsal head II–III, adolescents/young adults): Forefoot pain, load-dependent. Start conservatively; in advanced stages, surgical procedures (debridement, osteotomy, cartilage-bone reconstruction).
• Sesamoid osteonecrosis: rare; Therapy from relief, tape, insoles to targeted drilling up to sesamoidectomy in exceptional cases.

Course and prognosis

The course depends heavily on the location, stage, cause and the consequence of the relief. Lesions that are detected early and do not collapse may settle or stabilize. Collapse can result in permanent deformities and joint wear, which often require structural measures.

• Timeline: weeks to months of relief; Complete healing varies from person to person
• Sport and work: gradual return with load control; High-impact sport only after approval
• Risk of relapse/progression: increased if risk factors persist (nicotine, overload, metabolic factors)

Prevention and self-help

• Check and – if possible – reduce risk factors (smoking, alcohol, metabolic control)
• Medications such as systemic cortisone only after strict indications and medical supervision
• Optimize foot statics: supply insoles, suitable shoes (sufficient space, cushioning, rocker sole if necessary)
• Dose the load: increase the load slowly and plan regeneration times
• Maintain strength and mobility: foot and leg axis-friendly training, calf and foot muscles

When to see a doctor? Take warning signs seriously

• Persistent foot/ankle pain for several weeks despite rest
• After an accident: increasing pain, pain at rest, swelling, inability to bear weight
• Newly occurring misalignments, palpable crepitations or a feeling of instability
• Previous illnesses/medications with increased risk (e.g. long-term cortisone) and new foot pain

If you experience severe pain, overheating or fever, please seek medical advice immediately to rule out infections.

Your treatment in Hamburg

In our orthopedic practice at Dorotheenstrasse 48, 22301 Hamburg, we offer a differentiated diagnosis and a step-by-step, evidence-oriented treatment of osteonecrosis of the foot - conservatively and, if appropriate, with joint-preserving or stabilizing procedures in cooperation with specialized centers. The goal is a solution that is suitable for everyday use and sports without unnecessary risks.