Navicular Fractures

The tarsal navicular is the keystone of the medial longitudinal arch, and its fractures run from a minor dorsal avulsion to a comminuted body fracture with significant displacement and associated injuries. They are rare, 3-5% of all foot fractures, and they matter out of proportion to their number because of what a shortened medial column or a dead central third costs the foot.

Mechanism and who. Avulsion fractures are low-energy injuries, a capsule or ligament pulling off a fragment, and occur at any age. Body fractures are often the product of high-energy axial loading through the foot, with a male predominance and a peak age of 20-40 years. Tuberosity fractures come from avulsion by the posterior tibial tendon or a direct blow, in older patients or after trauma. Stress fractures belong to the athlete under repetitive load: track and field, basketball and football.

The four types. Frequency, imaging, treatment and prognosis differ enough that each type is handled as its own injury on the rest of this page.

The navicular stress fracture, the insidious, high-risk, slow-healing injury of the running and jumping athlete, is a distinct entity with its own mechanism, imaging threshold and non-weight-bearing-first management, and is covered in depth on the Navicular Stress Fracture page. It appears here alongside the acute traumatic fractures wherever the anatomy and the reasoning are shared.

The bone. Boat-shaped (Latin navicula, a little boat), the navicular articulates with the talus proximally, the three cuneiforms distally and the cuboid laterally. The posterior tibial tendon inserts on its tuberosity and is the major dynamic support of the arch; the spring ligament supports its plantar surface. With the talus it forms the talonavicular joint, part of the Chopart (transverse tarsal) joint and critical for hindfoot motion.

The medial column. Talus, navicular, medial cuneiform and first metatarsal make up the medial column, and the navicular is its cornerstone, maintaining the height of the longitudinal arch. Shorten it and the foot falls into planovalgus, which is why restoring medial column length is the recurring goal of treatment.

The talonavicular joint. It provides 80% of hindfoot inversion and eversion, the movement that lets the foot adapt to uneven ground. Losing that motion significantly affects function.

The blood supply. Dorsal branches of the dorsalis pedis artery and plantar branches of the medial plantar artery enter the bone from its periphery, medially and laterally. Neither reliably reaches the central third of the body, which is left as a watershed zone, relatively avascular: the same tenuous arrangement as the scaphoid in the wrist, and the same susceptibility to AVN.

Why it matters. Because the centre depends on vessels that arrive from the edges:

• Central stress fractures sit in the watershed, which is why they have a high nonunion rate
• A displaced body fracture disrupts the peripheral supply, which is the anatomical reason for the AVN rate given under Complications
• Open reduction should preserve the soft-tissue attachments that carry what supply there is

Radiographs. A standard foot series of AP, lateral and oblique views. Body fractures are usually visible. Stress fractures are negative on the first films in up to 70%, so look for a subtle cortical break or sclerosis.

CT is essential for body fractures and is the study the operation is planned from. It shows the articular displacement and lets the step-off be measured, defines the comminution pattern and the medial column length, identifies adjacent injuries, and confirms the Sangeorzan type.

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MRI is the gold standard for stress fractures, 97% sensitive, showing T2 bone marrow oedema before any cortical break and the soft-tissue injury around it. The fracture line is low signal on T1 and the marrow oedema high signal on T2 and STIR; the line lies in the central third in the sagittal plane, and MRI shows whether it is partial or complete. Both CT and MRI may be needed for a complete evaluation.

Bone scan is the alternative for a stress fracture: highly sensitive because uptake is early, less specific than MRI, since the navicular is "hot" in stress fracture and stress reaction alike.

Early. Wound dehiscence, infection, hardware prominence and neurovascular injury. The late complications are the subject of the rest of this section: AVN, nonunion, malunion with planovalgus, and the post-traumatic arthritis and chronic pain quantified under Outcomes.

Avascular necrosis. AVN follows about 25% of body fractures (reported range 16-25%), the direct consequence of the watershed supply. The risk rises with:

• Sangeorzan Type 2 and 3 fractures
• Delayed treatment
• Open reduction with extensive soft-tissue stripping
• Associated injuries that disrupt the blood supply

It presents as persistent pain despite apparent healing, then progressive collapse on imaging, sclerosis followed by fragmentation. It develops within the first 2 years of injury and may revascularise in 30% of cases, but progresses to collapse in 50-70% when severe and often ends in a salvage fusion. Early AVN is managed with protected weight-bearing, which may allow revascularisation. Established AVN with collapse needs bone grafting, vascularised or non-vascularised, talonavicular fusion, or a triple arthrodesis in severe cases.

Nonunion. The risk factors are central stress fractures in the watershed zone, inadequate immobilisation, smoking, delayed diagnosis and poor blood supply. Treatment runs from a bone stimulator, electrical or ultrasound, through surgical fixation with bone grafting, to a vascularised bone graft for resistant cases.

Malunion. A short medial column malunites into the planovalgus deformity described under Anatomy, with talonavicular arthritis, altered gait mechanics and chronic midfoot pain. Osteotomy and bone grafting are rarely successful; malunion typically requires talonavicular fusion, and severe deformity may need a triple arthrodesis.

0-2 weeks. In hospital: posterior splint, strict elevation above the heart, non-weight-bearing with crutches, ice and analgesia, neurovascular checks, and DVT prophylaxis if high risk. The patient goes home to maintain non-weight-bearing, keep the splint dry and clean, elevate as much as possible, and watch for excessive pain, swelling or numbness.

2-6 weeks. At 2 weeks the wound is checked and the sutures removed, the splint converted to a short leg cast or CAM boot, non-weight-bearing continues strictly, and ankle pumps and toe exercises begin. At 4 weeks, X-rays assess alignment and, if stable, gentle ankle range of motion in the boot may start. At 6 weeks, X-rays assess early healing, with CT if healing is questionable, and non-weight-bearing continues until bridging callus is seen.

6-12 weeks. At 8 weeks, if healing is progressing, progressive weight-bearing begins, as tolerated in the boot, with physiotherapy for range of motion and proprioception and pool therapy if available. From 10-12 weeks the patient transitions to a supportive shoe, continues progressive weight-bearing, advances strengthening and has any gait abnormality addressed.

3-6 months. Months 3-4 bring full weight-bearing in supportive footwear and the start of sport-specific rehabilitation, with impact activities still avoided. Months 4-6 bring a gradual return to running for the athlete, sport-specific drills, and full return to sport once pain-free with a full range of motion; hardware is removed if prominent, which is rarely needed.

Return to sport. Clearance requires all of the following:

• Pain-free weight-bearing and walking
• Full or near-full range of motion compared with the contralateral side
• Radiographic union, bridging callus on CT
• Successful completion of sport-specific drills
• Single-leg hop test equal to the contralateral side
• Psychological readiness

Global Epidemiology

Navicular fractures are uncommon. Across published series the navicular accounts for only a small fraction of foot fractures, with body fractures usually following high-energy axial loading and stress fractures clustering in running and jumping athletes. There is no dedicated international registry for navicular fractures (unlike arthroplasty), so the evidence base is built from case series and a single meta-analysis rather than registry data.

Guideline & Society Positions

No single national body publishes a stand-alone navicular-fracture guideline; recommendations are drawn from foot-and-ankle society consensus, AO principles and the sports-medicine literature. The table below summarises the practical position of the major bodies.

Registry & Practice Variation

• No arthroplasty-style registry captures navicular fractures, so practice variation is large and outcome data come from single-centre series.
• Stress-fracture management has converged internationally on strict non-weight-bearing immobilisation following Khan 1992 and the Torg 2010 meta-analysis; however, real-world audits (e.g. Burne 2005, PMID 16157855) show many patients still do not receive guideline non-weight-bearing treatment, and only about half of those return to their previous sporting level.
• Body-fracture fixation varies between independent lag screws and minifragment/bridge plating depending on comminution and surgeon preference; both achieve high union when medial column length is restored.
• Return-to-running and bone health are integral to stress-fracture care worldwide: once imaging confirms union, athletes progress through structured, graded load-progression (return-to-running) protocols, and recurrent stress fractures prompt systematic bone-health screening (energy availability, vitamin D and menstrual function) to correct underlying risk factors before return to full loading.

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