Fractures And Dislocations Of The Foot 2

Modern Study Review (AI-Generated)

High-Yield Summary

Fractures and dislocations involving the bases of the metatarsals, particularly the second metatarsal, represent complex midfoot injuries with potential for instability and long-term dysfunction. The second metatarsal base is a keystone for Lisfranc joint stability due to its rigid ligamentous attachments, making accurate diagnosis and management critical to prevent chronic pain and deformity. Modern treatment emphasizes early recognition, precise reduction, and stable fixation to restore foot biomechanics and optimize functional outcomes.

Key Diagnostic Findings

Anatomy

• The second metatarsal base is tightly bound by strong ligamentous structures, including the Lisfranc ligament, creating a stable “keystone” articulation with the medial cuneiform.
• The articulation between the first and second metatarsal bases lacks strong reinforcement, predisposing this area to instability in dislocations.
• Adjacent bones of concern include the navicular, cuboid, and cuneiforms, which contribute to midfoot stability.

Clinical Presentation

• Patients often present with midfoot pain, swelling, and difficulty bearing weight.
• Pain on passive supination/pronation of the foot is a key clinical sign indicating midfoot instability.
• Dislocations may spontaneously reduce, making clinical suspicion essential despite normal-appearing radiographs.

Imaging

• Radiographic landmarks:
• Congruity between the medial border of the 2nd metatarsal and the medial border of the middle cuneiform.
• Congruity between the medial border of the 4th metatarsal and the medial border of the cuboid.
• Look for fractures of the navicular, cuboid, cuneiforms, or metatarsal bases to raise suspicion of complex injury.
• Weight-bearing foot radiographs and advanced imaging (CT or MRI) may be necessary for subtle injuries.

Classification Systems

Note: The Quenu and Kuss classification remains a useful clinical framework but has been supplemented by more detailed Lisfranc injury classifications focusing on ligamentous disruption patterns.

Current Gold Standard Treatment

Non-operative Indications and Treatment

• Non-operative management may be considered only if the joint is anatomically reduced and stable, with no displacement >2 mm or talometatarsal angle >15°.
• Immobilization in a cast or boot with strict non-weight bearing for 6-8 weeks.
• Close clinical and radiographic follow-up is essential due to risk of secondary displacement.

Operative Indications and Treatment

• Open Reduction and Internal Fixation (ORIF) is indicated for:
• Displacement >2 mm.
• Talometatarsal angle >15°.
• Any evidence of instability or incongruity on imaging.
• Surgical approach: dorsal longitudinal incision over the 1st/2nd interspace provides optimal access to the second metatarsal base.
• Be vigilant for entrapment of the anterior tibial tendon, which can block reduction of the second metatarsal.
• Fixation options include:
• Stout Kirschner wires (K-wires, typically 0.062 inch).
• Interfragmentary screws for rigid fixation.
• Early mobilization after stable fixation is encouraged to optimize functional recovery.

Modern Complications & Outcomes

Complications

Outcomes

• Successful anatomic reduction and stable fixation correlate strongly with good pain relief and restoration of foot function.
• Residual displacement or instability often leads to chronic pain, deformity, and impaired gait.
• Early diagnosis and treatment are paramount to optimize long-term outcomes and minimize the risk of secondary arthritis.

Classic Clinical Notes

Fractures and dislocations of the foot 2

• Base of the second metatarsal. Note that there lacks such strong reinforcement between the first and second metatarsal bases, making this an area of instability.
• The key radiographic landmarks are:
• Congruity from the medial border of the 2nd metatarsal and the medial border of the middle cuneiform.
• Congruity from the medial border of the 4th metatarsal and the medial border of the cuboid.

Classification (Quenu, Kuss)

• Homolateral – all five metatarsals going in one direction
• Isolated – one or two metatarsals
• Divergent – usually between the first and second metatarsals

• Needs careful clinical examination: these dislocations may reduce and look okay on xray, so you may overlook the severity of the injury.
• Look for pain on passive supination/pronation of the foot.
• On xray, fractures of the navicular, cuboid, cuneiforms, or of the metatarsal bases (particularly the second metatarsal) should make your suspicion increase.

Treatment

• Some authors have recommended cast treatment if the joint is reduced. Others suggest that the reduction can be lost when the swelling subsides and recommend fixing them.
• It would appear that the most reliable way to treat these is to fix them; certainly, any displacement warrants reduction and stabilization.
• Myerson’s guidelines – ORIF if >2mm displacement or a talometatarsal angle of > 15°.
• ORIF can be done through a dorsal longitudinal incision over the 1st/2nd interspace – this gives access to the 2nd metatarsal head which is usually the tough one to get reduced. Be aware that an entrapped anterior tibial tendon can block the reduction of the 2nd metatarsal.
• Fixation either with stout K-wires (0.062) or interfrag screw.

Last Updated on January 25, 2026 by orthonet