Midfoot arthritis is a painful and debilitating condition for which many patients seek the clinical care of a foot and ankle specialist. Similar to arthritis in other joints, midfoot arthritis can arise from primary, inflammatory, or posttraumatic etiologies. Owing to the different etiologies, midfoot arthritis appears in both younger and older populations. Management of midfoot arthritis usually begins conservatively with activity modification, shoe modification, orthotics, physical therapy, systemic anti-inflammatory medication, and local joint injection. Surgical treatment is considered the “last resort” for progressively worsening deformity, pain, and disability of the midfoot.

The midfoot is the junction region connecting the forefoot (metatarsals) to the hindfoot (talus and calcaneus). Multiple ligaments, tendons, capsules, interconnected joints, and bony configurations contribute to the construction of this vital junction. The midfoot serves as a stable, load-transferring segment in the unique, bipedal locomotion of human beings.

Articulating between the metatarsals, the three navicular facets, and the cuboid, the midfoot has three distinct longitudinal columns: medial, middle, and lateral (Figure 1). The medial column consists of the medial cuneiform-first metatarsal articulation. The middle column includes the middle cuneiform-second metatarsal joint, the lateral cuneiform-third metatarsal joint, and the intercuneiform joints. The lateral column is composed of the cuboid-fourth metatarsal and the cuboid-fifth metatarsal articulations. The “keystone and wedged” arrangement of the bones of the midfoot joint complex resemble a Roman arch, with the apex at the second metatarsal recessed 4 to 8 mm between the medial and lateral cuneiforms.¹

In addition to the bony configuration, the midfoot is composed of a strong and complex network of ligamentous connections. Dorsal, plantar, and intercuneiform ligaments provide increased stability to the midfoot. Intermetatarsal ligaments connect the bases of the second through fifth metatarsals to one another. There is no intermetatarsal ligament between the proximal first and second metatarsals. The Lisfranc ligament is the largest ligament of the midfoot ligamentous complex. It links obliquely between the medial cuneiform and the base of the second metatarsal and is comprised of three components: dorsal, plantar, and interosseous. The plantar component connects the second and third metatarsals with the medial cuneiform and is the strongest ligament
in the Lisfranc complex. Stability of the midfoot is further enhanced by the plantar beam of peroneus longus as well as contributions from the plantar fascia, anterior tibialis, posterior tibialis, and flexor hallucis brevis.²

Motion of the midfoot is variable at each joint due to dynamic relationships between the bones of the midfoot. For instance, although the relative motion between the navicular and cuboid bones at the transverse tarsal (Chopart) joint is minor, it plays a significant role in the phases of the gait cycle. When the axis of the Chopart joint is parallel, the foot is flexible and becomes a shock absorber during midstance. When the axis is not parallel, the Chopart joint becomes rigid and acts as a lever for propulsion during the toe-off.³ The relationship between the Chopart joint and the midfoot complex allows for effective load transfer from the hindfoot and ankle into the midfoot and forefoot.

An in vitro study of midfoot motion has shown that the three columns of the midfoot vary at each joint during dorsiflexion-plantarflexion and supination-pronation, with the lateral column having considerably more motion than the medial and middle columns. In the sagittal plane and during supination-pronation, the cuboid-metatarsal joints have approximately 10° of motion, whereas motion at the medial, middle, and lateral cuneiform-metatarsal joints was 3.5°, 0.6°, and 1.6°, respectively.⁴ In addition, the second and third tarsometatarsal (TMT) joints have been shown to bear most of the force in the midfoot. As such, the rigid middle column construct may contribute to the more often symptomatic nature of second and third metatarsal-cuneiform arthritis.⁵

Similar to arthritis in other joints, midfoot arthritis can arise from primary degeneration, inflammatory processes, or posttraumatic damage. Owing to the different etiologies, the age distribution of midfoot arthritis appears to be bimodal: young patients in their thirties with a history of midfoot trauma and elderly patients older than 50 years with primary arthritis.⁶ The most common cause of midfoot arthritis is posttraumatic, followed by primary degeneration, and lastly, inflammatory or neuropathic changes.

Injury-related cartilage damage can lead to arthrosis of the midfoot joint complex. Of the various types of midfoot injuries, the incidence rate for midfoot fracture-dislocation is about 0.2%.⁷ However, there is
a 20% rate of missing a fracture-dislocation injury of the midfoot.⁸ Thus, it is possible that the incidence of midfoot fracture-dislocation is higher than reported. Furthermore, the development of symptomatic, degenerative arthritis following TMT fracture-dislocation is reported to range from 0% to 58%.⁹

Development of midfoot arthritis is also related to individual anatomic and biomechanical factors. Long-standing pes planus, first ray instability, short first metatarsal, and long second metatarsal may predispose to deformity and arthritis of the midfoot.¹⁰ The classic deformities of midfoot arthritis include forefoot abduction, collapse of the longitudinal arch, and valgus heel alignment. Collapse of the longitudinal arch results in increased plantar tension and compromises the midfoot lever function during the gait cycle. In addition, sagittal and coronal deformities such as rocker bottom foot and hallux valgus may be present.⁶ Patients with painful midfoot arthritis also demonstrate significantly less first metatarsal plantarflexion excursion during walking and significant calcaneus eversion on step descent when compared with matched controls.¹¹ The degenerative process can also result in formation of dorsal and plantar osteophytes which make shoe wear difficult and may cause callus or ulceration. Injury, inflammation, degeneration, and deformity can cause progressive articular cartilage damage and loss of bony and soft-tissue integrity that result in the painful and debilitating symptoms of midfoot arthritis.

Pain with loading of the midtarsal region is the most commonly reported symptom of midfoot arthritis. Pain of the midfoot severely restricts a patient’s ability to walk and perform daily activities.¹² Pain usually increases with weight bearing, especially with forced plantarflexion, such as walking up stairs. Patients also often report a deep aching pain that is present at rest. Palpable, bony prominences may appear dorsally and/or plantarly and are associated with swelling and pain that is worse with wearing closed shoes. Pain due to irritation of the deep peroneal nerve can also occur due to osteophytes and ganglion cysts developing from capsular rents at the anterior tarsal tunnel. A detailed history of midfoot trauma and inflammatory or neuropathic disease needs to be assessed during the clinical encounter.

Physical examination in standing, seated, and dynamic (ie, walking) positions are routinely performed. Special attention should be taken during the standing examination to observe midfoot alignment and deformities in the sagittal and coronal planes. Palpation of the maximum pain region occurs during the seated examination. Arthritis-associated pain can be reproduced with the piano key sign or an abduction-pronation stress test of the midtarsal joint.¹³ The Coleman block test and the Silfverskiold test should be performed when there is any misalignment observed and can assist in future surgical decision-making. Routine neurovascular examination should always be performed, especially when a neuroarthropathic etiology is suspected.

Standing AP, lateral, and oblique radiographs of the affected foot or feet are performed as part of the initial evaluation to identify the location and extent of the disease as well as to detect any deformity. A radiograph of primary midfoot arthritis may show a lower medial cuneiform height and a negative talo-first metatarsal angle (Meary angle) compared with those of traumatic midfoot arthritis. On radiograph, recognition of the apex of any collapse of the midfoot in the coronal and sagittal planes helps surgical decision-making and planning for future reconstruction.⁶ CT may be useful when there is symptomatic disease that is not easily revealed by plain radiographs. CT is usually done non-weight bearing and provides a three-dimensional reconstruction to show the extent of arthritis and deformities in the specific, symptomatic joints. In the past 10 years, Cone Beam CT technology has made weight-bearing CT imaging more readily available in the foot and ankle clinical setting.¹⁴ However, standardization and validation of measurement are still needed for future adoption of Cone Beam CT as a standard diagnostic approach.

When physical examination and imaging studies produce inconclusive information for further management guidance, selective joint injection of local anesthetics under ultrasonography or fluoroscopic guidance can be done. Selective local anesthetic injection can be very helpful when coupled with use of a pain diary to assist in identifying the diseased joints and ultimately allows for prediction of a future response to arthrodesis.