Navicular & Cuboid Fractures

Navicular and cuboid fractures are uncommon but clinically significant injuries of the midfoot. They can occur in isolation or as part of complex midfoot fracture-dislocation patterns. Misdiagnosis is common, and missed or malreduced injuries lead to chronic midfoot pain, collapse of the medial longitudinal arch, and significant functional impairment.

• Navicular: keystone of the medial longitudinal arch; articulates with talus proximally (talonavicular joint — most mobile midfoot joint), three cuneiforms distally, and cuboid laterally; blood supply enters peripherally — central third is relatively avascular (watershed zone) — risk of AVN with body fractures
• Cuboid: lateral column of the foot; articulates with calcaneus proximally, 4th and 5th metatarsal bases distally, and navicular / lateral cuneiform medially; peroneus longus groove runs inferiorly
• Navicular fractures: most common types are cortical avulsion fractures (most common overall), tuberosity fractures, and body fractures (most serious)
• Cuboid fractures: avulsion (most common), body fractures, and the clinically important nutcracker fracture (compression fracture between calcaneus and 4th/5th metatarsal bases)
• Both injuries are commonly associated with Lisfranc injury, calcaneal fractures, and polytrauma — assess midfoot systematically

The Sangeorzan classification (1989) is standard for navicular body fractures and guides operative planning.

• Cortical avulsion fractures: most common navicular fracture; dorsal capsular avulsion from talonavicular joint; treated with cast and weight bearing as tolerated; small fragments need no specific fixation
• Tuberosity fractures: avulsion of posterior tibial tendon insertion; distinguish from os naviculare (smooth edges, bilateral on X-ray) — os naviculare is a normal variant; do not confuse with acute fracture; acute tuberosity fractures treated with cast; large displaced fragments or PTT dysfunction may require fixation or reattachment
• Stress fractures of navicular: occur in athletes; insidious onset dorsal midfoot pain; often missed on plain X-ray — MRI or CT required; located in central third (watershed zone); non-weight bearing cast 6–8 weeks for incomplete fractures; ORIF for complete fractures or failed conservative treatment
• AVN of navicular: risk with displaced body fractures, stress fractures, and Kohler disease (paediatric AVN) — monitor with serial MRI
• ORIF principles: dorsal approach; restore navicular height and length to prevent medial column shortening and arch collapse; screws parallel to talonavicular joint; bone graft for comminuted defects; spanning bridge plate or external fixator if reconstruction not possible

• Avulsion fractures: most common type; peroneus brevis or plantar ligament avulsion; treated with cast or walking boot for 4–6 weeks
• Body fractures: direct trauma or high-energy mechanism; treat based on displacement and articular involvement
• Nutcracker fracture (cuboid compression fracture): lateral forefoot forced into abduction driving 4th/5th metatarsal bases into cuboid — lateral column shortening; associated with Lisfranc injury medially; requires ORIF to restore lateral column length
• Nutcracker fracture management: open reduction, bone graft to restore height, bridging plate from calcaneus to 4th/5th metatarsal bases; do not leave lateral column shortened — leads to lateral forefoot pain and progressive midfoot instability
• Peroneus longus groove: runs in plantar groove of cuboid — displaced cuboid fractures can impinge on or displace the peroneus longus tendon; assess tendon function in all cuboid injuries

• Plain radiographs (weight-bearing AP, lateral, oblique foot): first-line; may miss stress fractures and undisplaced body fractures; assess Cyma line (normal S-shaped alignment of talonavicular and calcaneocuboid joints on lateral)
• Disruption of the Cyma line = midtarsal (Chopart) joint instability — do not miss this on lateral foot X-ray
• CT scan: mandatory for body fractures, suspected nutcracker injury, and preoperative planning — defines comminution, articular involvement, and column alignment
• MRI: gold standard for navicular stress fractures; also identifies bone oedema, ligamentous injury, and AVN
• Bone scan: sensitive but non-specific; useful for detecting occult stress fractures when MRI unavailable
• Always assess for associated Lisfranc injury — obtain weight-bearing AP foot radiograph; look for widening between 1st and 2nd metatarsal bases and between medial and middle cuneiforms

• Post-traumatic arthritis: talonavicular joint most commonly affected after navicular body fractures; calcaneocuboid joint after cuboid fractures; incidence correlates with articular comminution and quality of reduction
• AVN of navicular: follows displaced body fractures; MRI surveillance recommended; may require navicular excision and bone graft reconstruction or talonavicular fusion in severe cases
• Medial column shortening: after missed or malreduced navicular fractures — planovalgus deformity, arch collapse, chronic pain; difficult to reconstruct late
• Lateral column shortening: after missed cuboid nutcracker — lateral forefoot pain, peroneus longus dysfunction, progressive midfoot instability
• Navicular stress fracture: non-union and refracture risk significant — strict non-weight bearing essential; premature return to sport leads to complete fracture and AVN
• Salvage options for failed midfoot: talonavicular fusion (navicular pathology), calcaneocuboid fusion (cuboid pathology), triple arthrodesis for global midfoot collapse

• Navicular stress fractures in athletes: high index of suspicion in any athlete with dorsal midfoot pain — plain X-rays negative in up to 80% early; MRI is investigation of choice; complete fractures or athletes who fail 6 weeks non-weight bearing should undergo ORIF with compression screw and strict return-to-sport protocol
• Talonavicular joint: most important joint for hindfoot motion — fusion of TN joint eliminates approximately 90% of subtalar and transverse tarsal motion; preserve where possible; fuse only when articular destruction is irreparable
• Column length restoration: the concept of medial and lateral column length is paramount in midfoot surgery — shortening of either column leads to predictable deformity and dysfunction; use spanning bridge plates and bone graft liberally rather than accept shortening
• Chopart (midtarsal) joint injuries: navicular and cuboid fractures may be part of a Chopart fracture-dislocation — high-energy injury; often associated with talar head fracture and calcaneal fracture; requires systematic reduction of both columns; outcomes generally poor
• Kohler disease: paediatric AVN of navicular; self-limiting in children; treat with arch support and activity modification; almost universally resolves with reconstitution of navicular in children under 7 years

• Central third of navicular is avascular — watershed zone; site of stress fractures and AVN
• Sangeorzan Type III = most comminuted navicular body fracture = worst prognosis
• Os naviculare = normal variant; bilateral; smooth edges — distinguish from acute tuberosity fracture
• Navicular stress fracture: negative plain X-ray in 80% — MRI required; non-weight bearing cast 6–8 weeks for incomplete fracture
• Nutcracker fracture = cuboid compression = lateral column shortening — ORIF with bone graft and bridging plate mandatory
• Cyma line disruption on lateral X-ray = Chopart (midtarsal) instability
• Talonavicular joint fusion = eliminates 90% of subtalar and transverse tarsal motion — only fuse when articular destruction is irreparable
• Peroneus longus runs in cuboid groove — assess tendon function in all displaced cuboid fractures
• Always exclude associated Lisfranc injury in midfoot fractures — weight-bearing AP foot X-ray essential
• Kohler disease = paediatric navicular AVN — self-limiting; conservative management in children under 7