Treatment of Second, Third, and Fourth Metatarsal Neck Fractures
Most fractures of the second, third, and fourth metatarsal necks with less than 10° of angulation and 3-4 mm of translation can be treated conservatively with protected weight bearing in a cast shoe for 4-6 weeks, while displaced fractures beyond these parameters require surgical fixation, typically with percutaneous K-wire pinning. 1, 2
Initial Assessment
Obtain three-view radiographs (posteroanterior, lateral, and oblique) to assess fracture displacement, angulation, and involvement of adjacent metatarsals, as up to 63% of third metatarsal fractures occur with second or fourth metatarsal involvement. 2
Carefully evaluate for Lisfranc ligament injury if midfoot trauma is present, as this requires specific treatment or referral. 3
Rule out conditions requiring emergent referral: neurovascular compromise, open fractures, or multiple displaced metatarsal fractures. 3
Treatment Algorithm
Non-Displaced Fractures (≤10° angulation, ≤3-4 mm translation)
Apply a soft dressing initially, followed by a firm supportive cast shoe with progressive protected weight bearing for 4-6 weeks. 1, 3
Allow early weight bearing as tolerated in a cast boot, as these fractures are typically stable. 1
No immobilization is required for simple stress fractures of the second through fourth metatarsal shafts; rest alone is usually sufficient. 3
Displaced Fractures (>10° angulation or >3-4 mm translation)
Perform closed reduction under fluoroscopic guidance using digital pressure for percutaneous manipulation. 4
Stabilize with percutaneous K-wire fixation as the primary surgical technique for most displaced lesser metatarsal neck fractures. 1, 4
Consider closed transverse pinning of the metatarsal heads, which is particularly advantageous in patients with osteoporotic bone or narrow medullary canals where antegrade pinning may fail. 4
Use open reduction with plate fixation only for fractures with joint involvement and multiple fragments that cannot be adequately reduced percutaneously. 1
Surgical Technique Considerations
Percutaneous K-wire fixation offers several advantages: relatively short operating time, allows early motion of the metatarsophalangeal joint, and is effective even with osteoporotic bone. 4
Avoid antegrade pre-bent K-wire techniques in osteoporotic patients or those with narrow medullary canals, as the bent distal end may penetrate the plantar cortex and prevent proper canal entry. 4
Adjacent fractures often remain stable within acceptable range due to intermetatarsal ligaments when the most displaced fracture is adequately fixed. 4
Common Pitfalls
Beware of plantar angulation: Displaced metatarsal neck fractures have a propensity for the distal fragment to angulate plantarward due to strong flexor tendons, leading to relative metatarsal shortening and poor outcomes. 4
Multiple metatarsal involvement is common: Up to 63% of third metatarsal fractures occur with adjacent metatarsal fractures, requiring careful inspection of all central metatarsals. 2
Proximal fourth metatarsal injuries heal slowly: These injuries at the shaft-base junction may require 2-8 months to return to activity and often need non-weight-bearing immobilization for 3 weeks followed by 3+ weeks of weight-bearing immobilization. 5
Expected Outcomes
Clinical and functional outcomes vary: Up to 39% of patients with central metatarsal fractures report poor results, particularly influenced by fracture pattern complexity and patient comorbidities. 2
Conservative treatment of non-displaced fractures typically heals well within 4-6 weeks with appropriate protected weight bearing. 1