Metatarsal & Phalangeal Fractures

Metatarsal and phalangeal fractures are among the most common fractures of the foot, collectively accounting for a significant proportion of emergency department attendances. While many are managed non-operatively, certain fracture patterns — particularly at the base of the 5th metatarsal and the 1st metatarsal/hallux — carry significant morbidity if mismanaged or misdiagnosed.

• Metatarsals 1–5; 1st is the largest and most weight-bearing (bears approximately 40% of forefoot load); 2nd–4th are lesser metatarsals; 5th is the most commonly fractured
• The lesser metatarsals (2nd–4th) are mechanically bound by intermetatarsal ligaments — fractures of these are generally more stable and heal predictably
• The 2nd metatarsal base is recessed into the Lisfranc joint and is the keystone of the transverse arch — stress fractures here are common in ballet dancers and military recruits ("march fracture")
• Phalanges: hallux has two phalanges; lesser toes have three; fractures most common at distal and proximal phalanx of lesser toes and proximal phalanx of hallux
• 5th metatarsal fracture zone anatomy is critical — the correct diagnosis (avulsion vs Jones vs stress) determines management entirely

The 5th metatarsal is divided into three zones. The zone of the fracture is the single most important factor in determining treatment and prognosis.

• Jones fracture (Zone 2): named after Sir Robert Jones (1902); occurs at the metaphyseal-diaphyseal junction where the medullary blood supply is poorest — watershed zone; nonunion rate up to 30% with non-operative treatment
• Zone 1 avulsion fracture: most common; do not confuse with os vesalianum (normal variant — smooth, bilateral, no acute oedema on MRI)
• Zone 3 stress fracture: insidious onset; prodromal pain; seen in overuse athletes; intramedullary sclerosis on X-ray indicates chronicity — ORIF recommended for complete fractures or athletes requiring early return to sport
• ORIF technique for Jones fracture: intramedullary solid or cannulated screw (4.0–5.5 mm); engage distal cortex; screw diameter should fill medullary canal — undersized screw leads to failure; postoperative NWB 6 weeks then progressive weight bearing

• 1st metatarsal carries the greatest weight-bearing load — fractures here have significant functional implications if malreduced
• Shaft fractures: generally stable if undisplaced — short leg cast or walking boot; ORIF for displaced fractures (>3–4 mm displacement or >10° angulation)
• Base fractures: assess carefully for associated Lisfranc injury — medial cuneiform-1st metatarsal joint involvement; weight-bearing AP X-ray mandatory
• Shortening of 1st metatarsal after fracture malunion: transfers load to lesser metatarsals — causes metatarsalgia and transfer lesions under 2nd/3rd metatarsal heads; avoid shortening in operative management
• Plantar plate and sesamoid complex: sesamoid fractures associated with 1st metatarsal injuries; assess separately — bipartite sesamoid (normal variant, bilateral) vs acute fracture (irregular edges, MRI shows oedema)

• Most isolated lesser metatarsal fractures heal with non-operative management — cast or stiff-soled shoe; weight bearing as tolerated
• Acceptable alignment: <10° dorsoplantar angulation, <3–4 mm displacement, <4 mm shortening — beyond these, consider operative management
• Dorsal angulation creates a plantar prominence under the metatarsal head — causes transfer metatarsalgia; must be corrected
• Multiple metatarsal fractures: more unstable; loss of the metatarsal cascade — ORIF more often required to restore forefoot architecture
• 2nd metatarsal base stress fracture (march fracture): insidious onset forefoot pain; radiograph negative initially — MRI or bone scan diagnostic; NWB and activity modification; reassess for Lisfranc instability

• Lesser toe fractures: the vast majority are managed non-operatively — buddy taping to adjacent toe, stiff-soled shoe for 3–4 weeks; weight bearing as tolerated
• ORIF for lesser toe phalangeal fractures only when: open fracture, significant rotational deformity, irreducible intra-articular displacement, or associated dislocation
• Hallux (great toe) fractures: require more careful management — proximal phalanx fractures with >2 mm articular step, >10° angulation, or significant displacement should be reduced and fixed
• Sesamoid fractures: acute fractures treated with off-loading orthosis and padding; stress fractures in athletes may require prolonged rest; sesamoidectomy reserved for failed conservative treatment — risk of hallux valgus or varus deformity after excision
• Turf toe = plantar plate injury at 1st MTP joint; hyperextension mechanism; sprains graded I–III; Grade III (complete plantar plate rupture) may require surgical repair in athletes
• Subungual haematoma associated with distal phalanx fractures — trephination for pain relief; assess nail bed injury

• Jones fracture in elite athletes: primary ORIF with intramedullary screw is now standard of care for high-demand athletes — allows earlier return to sport (8–12 weeks vs 16–20 weeks non-operative); screw diameter must fill medullary canal to avoid failure; use solid screw rather than cannulated where canal size allows — greater fatigue strength
• Refracture after Jones ORIF: occurs in up to 10–15% even after apparent radiographic union — premature return to sport; repeat ORIF with larger screw or bone grafting of medullary canal
• Metatarsal cascade: the parabolic curve of metatarsal heads on AP weight-bearing X-ray — disruption after fracture malunion causes transfer metatarsalgia; restoration of cascade is a key operative goal in multiple metatarsal fractures
• Floating toe deformity: complication of excessive shortening after metatarsal fracture — disrupts plantar plate mechanism; toe floats off ground; very difficult to correct; avoid shortening at time of fixation
• Lisfranc association: any metatarsal base fracture (particularly 2nd) must prompt assessment for Lisfranc injury — weight-bearing AP foot X-ray; if gap >2 mm between 1st and 2nd metatarsal bases or between medial and middle cuneiform, Lisfranc injury confirmed and operative treatment indicated

• Zone 1 = avulsion (benign); Zone 2 = Jones fracture (high nonunion); Zone 3 = stress fracture (high refracture)
• Jones fracture = Zone 2; watershed blood supply; nonunion up to 30% with conservative treatment
• Jones fracture in athlete = primary ORIF with intramedullary screw — fills medullary canal; solid screw preferred
• Os vesalianum = normal variant at 5th metatarsal base; bilateral; smooth — distinguish from Zone 1 avulsion fracture
• 1st metatarsal shortening = transfer metatarsalgia under 2nd/3rd heads — avoid shortening in operative management
• Dorsal angulation of lesser metatarsal = plantar prominence = transfer metatarsalgia — must correct
• Turf toe Grade III = complete plantar plate rupture at 1st MTP — surgical repair in athletes
• March fracture = 2nd metatarsal base stress fracture; negative X-ray early; MRI diagnostic; exclude Lisfranc
• Any 2nd metatarsal base fracture — exclude Lisfranc injury with weight-bearing AP foot X-ray
• Bipartite sesamoid = bilateral, smooth edges; acute sesamoid fracture = irregular, MRI oedema