Tarsometatarsal vs Metatarsocuneiform Joint: Anatomic Clarification and Clinical Management
Anatomic Relationship
The tarsometatarsal (TMT) joint and metatarsocuneiform joint refer to the same anatomic structure—they are synonymous terms for the articulation between the metatarsal bases and the tarsal bones (cuneiforms and cuboid). 1, 2 This joint complex, also known as the Lisfranc joint, is most commonly affected at the metatarso-cuneiform and naviculo-cuneiform articulations in the midfoot. 3
The first metatarsocuneiform joint specifically describes the articulation between the first metatarsal base and the medial cuneiform, while the second and third metatarsocuneiform joints involve the intermediate and lateral cuneiforms respectively. 4, 5 The articulation between the medial cuneiform and base of the second metatarsal serves as the keystone to midfoot integrity. 6, 7
Diagnostic Approach
Initial Imaging
Weight-bearing radiographs (anteroposterior, oblique, and lateral views) are mandatory as the first-line imaging study, since non-weight-bearing films are unreliable for detecting subtle injuries. 1, 2
An additional anteroposterior view with 20° craniocaudal angulation improves visualization of the Lisfranc joint complex. 1
Bilateral imaging helps detect subtle malalignment when compared to the uninjured contralateral side. 1
Look specifically for diastasis between the first and second metatarsal bases and the "fleck" sign (avulsion fracture fragment). 1
Advanced Imaging When Radiographs Are Negative
CT is the primary imaging technique for acute hyperflexion injuries, high-energy polytrauma, patients unable to bear weight, and when multiple metatarsal and cuneiform fractures are present. 1, 2 In polytrauma patients, approximately 25% of midfoot fractures identified on CT are overlooked on radiographs. 1
MRI is indicated when radiographs are normal but clinical suspicion remains high, particularly for purely ligamentous injuries without diastasis. 1, 2 MRI shows high correlation with intraoperative findings for unstable Lisfranc injuries and is superior with 3-D volumetric acquisitions. 1
MRI is also the imaging modality of choice for investigating osteomyelitis in diabetic foot complications, with sensitivity of 77-100% and specificity of 80-100%. 3
Treatment Algorithm
Non-Operative Management
- First- and second-degree sprains without diastasis may be managed conservatively with immobilization and protected weight-bearing. 8
Operative Management
Third-degree sprains (with diastasis), fractures, and frank dislocations require open reduction and internal fixation for optimal functional outcomes, as nonoperative treatment does not reliably produce good results. 7, 8
Surgical Technique
The medial three rays (first, second, and third TMT joints) should be fixed with screw fixation, while the fourth and fifth TMT joints are stabilized with Kirschner wires. 7
Achieving optimal anatomic reduction and ensuring stability of the tarsometatarsal joints directly impacts outcomes—failure to achieve anatomic reduction leads to post-traumatic arthritis, foot deformities, and significant disability. 2, 6
Prophylactic antibiotics (such as cefazolin) should be administered prior to incision. 2
Postoperative Care
Extremity elevation to minimize swelling and appropriate pain management are essential. 2
Physical therapy should be initiated after K-wire removal, approximately 6-8 weeks post-surgery. 2
Regular radiographic assessment is necessary to monitor reduction and healing, with surveillance for post-traumatic arthritis, which occurs in approximately 25% of cases despite anatomic reduction. 2
Salvage Procedures
First metatarsocuneiform joint arthrodesis is indicated for severe deformity, post-traumatic arthritis, excessive motion at the first metatarsocuneiform joint, or as a salvage procedure in reconstructive forefoot surgery. 6, 4, 5 This procedure has shown very good long-term results for reducing the intermetatarsal angle and limiting abnormal motion, with few complications. 5 Arthroscopic approaches are also described for post-traumatic arthritis. 4
Critical Pitfalls to Avoid
Up to 20% of tarsometatarsal joint complex injuries are missed on initial examination—maintain high clinical suspicion for midfoot pain after even minor forefoot injury. 7
Relying solely on non-weight-bearing radiographs leads to missed diagnoses. 1, 2
Delayed diagnosis and inadequate treatment result in poor functional outcomes, with some patients unable to return to sports and requiring eventual fusion. 8
In diabetic patients with neuropathy, standard clinical tests may be less reliable, and patients may be able to bear weight despite fractures—imaging should be performed more liberally. 1, 9