### High-Yield Summary
– The Myerson classification stratifies Lisfranc injuries based on the direction and extent of tarsometatarsal joint displacement, guiding surgical approach and fixation strategy.
– Type A involves total incongruity; Type B involves partial incongruity (medial or lateral); Type C involves divergent displacement.
– Accurate diagnosis requires weight-bearing radiographs and CT imaging to assess subtle displacement and comminution.
– Operative management is indicated for any displacement >2 mm or instability; fixation aims to restore anatomic alignment and joint congruity.
– Surgical approach and implant choice depend on injury pattern: transarticular screws for medial column, bridge plating for lateral columnand combined fixation for divergent injuries.
### Clinical Fundamentals
The Lisfranc joint complex comprises the tarsometatarsal articulations between the first, secondand third metatarsals and the cuneiforms, plus the fourth and fifth metatarsals with the cuboid. The second metatarsal base is the keystone, recessed between the cuneiforms, providing inherent stability. The Lisfranc ligament, spanning from the medial cuneiform to the base of the second metatarsal, is the primary stabilizer preventing lateral displacement.
Biomechanically, the Lisfranc joint transmits axial load and allows limited rotational and translational motion. Disruption leads to instability, altered load distributionand early post-traumatic arthritis. Epidemiologically, Lisfranc injuries are uncommon but frequently missed, especially in low-energy mechanisms, with high-energy trauma more likely to cause complete dislocations.
### Classification & Diagnosis
| Myerson Classification | Description | Clinical Implication |
|———————–|——————————————|———————————————-|
| Type A | Total incongruity: all metatarsals displaced in one direction (medial or lateral) | Requires comprehensive reduction and fixation of all columns |
| Type B1 | Partial incongruity: medial displacement of first metatarsal with intact lateral column | Focused fixation on medial column; lateral column stable |
| Type B2 | Partial incongruity: lateral displacement of lesser metatarsals with intact medial column | Fixation of lateral column; medial column stable |
| Type C1 | Divergent displacement: partial displacement with first metatarsal lateral and lesser metatarsals medial | Complex fixation addressing both columns |
| Type C2 | Divergent displacement: total displacement with first metatarsal lateral and lesser metatarsals medial | Extensive fixation and possible ligamentous repair |
Diagnostic pearls include the necessity of weight-bearing AP, lateraland oblique radiographs to detect subtle diastasis. CT scans are invaluable for delineating fracture patterns and comminution. Common pitfalls include overlooking subtle displacement less than 2 mm and misinterpreting overlapping bones on non-weight-bearing films.
### Decision-Making Algorithm
Non-operative management is reserved for purely ligamentous injuries without displacement (<2 mm) and stable on stress examination. Operative intervention is indicated for:
– Displacement >2 mm on weight-bearing radiographs or CT
– Evidence of joint instability or incongruity
– Associated fractures compromising joint stability
Surgical approach selection depends on injury type:
– Type A injuries require dorsal longitudinal incisions over the first and lesser metatarsals to access all columns.
– Type B injuries allow targeted approaches: medial for B1, lateral for B2.
– Type C injuries necessitate combined medial and lateral approaches for adequate visualization and fixation.
Implant choice is guided by biomechanical demands:
– Transarticular screws provide rigid fixation for medial column injuries.
– Bridge plating is preferred for lateral column to preserve joint motion and avoid articular cartilage violation.
– Divergent injuries require a combination of screws and plates to restore multiplanar stability.
### Surgical Mastery & Pearls
Begin with thorough debridement and exposure of the tarsometatarsal joints. Achieve anatomic reduction by restoring the second metatarsal base alignment with the medial cuneiform, using fluoroscopy to confirm congruity in all planes. Temporarily stabilize with K-wires before definitive fixation.
For Type A injuries, sequential fixation from medial to lateral columns optimizes stability. Use 3.5 mm cortical screws for medial column transarticular fixation, ensuring screw trajectory avoids joint penetration. Bridge plating on the lateral column preserves joint motion and reduces hardware prominence.
In Type B injuries, focus fixation on the displaced column, preserving the stable column to minimize soft tissue dissection. Divergent Type C injuries require careful balancing of fixation to prevent residual instability; consider ligamentous repair or augmentation if instability persists after bony fixation.
Intraoperative red flags include persistent diastasis after fixation, malalignment on fluoroscopyand hardware placement violating articular surfaces. Confirm reduction with intraoperative CT or 3D fluoroscopy if available.
### Evidence-Based Synthesis
Recent literature emphasizes the importance of anatomic reduction and stable fixation to prevent post-traumatic arthritis and improve functional outcomes. Comparative studies demonstrate superior outcomes with open reduction and internal fixation (ORIF) over closed management in displaced injuries. The Myerson classification remains the most clinically relevant system, correlating well with injury severity and guiding surgical strategy.
Controversy persists regarding the optimal fixation method for the lateral column, with some evidence favoring bridge plating to preserve joint motion, while others report equivalent outcomes with transarticular screws. Emerging data suggest that early weight-bearing protocols may be safe in stable fixations, but consensus is lacking.
The role of primary arthrodesis in purely ligamentous Lisfranc injuries with severe instability is evolving, with some trials showing improved long-term outcomes compared to ORIF, though patient selection remains critical.
### Master Class Pro-Tip
Mastery in managing Lisfranc injuries hinges on restoring the second metatarsal-cuneiform relationship as the cornerstone of foot architecture. Prioritize anatomic reduction over rigid fixation; subtle malalignment under 2 mm significantly increases arthritis risk. Utilize intraoperative fluoroscopy judiciously, but do not hesitate to employ intraoperative CT for complex or divergent injuries. When bridging the lateral column, contour plates meticulously to avoid soft tissue irritation and preserve peroneal tendon gliding. Finally, anticipate and address ligamentous insufficiency intraoperatively-augment with suture anchors or grafts when reduction is tenuous despite bony fixation. This nuanced approach elevates outcomes from competent to exceptional.
