How To Treat Cuboid Syndrome In The Athlete
Consider the following presentations of athletes. A 35-year-old male ballet dancer presents to your office with an antalgic gait. He experienced sudden lateral foot pain in the left foot after making a slightly off-balance landing from a jump. He also complains of left foot weakness and fears that he may not be able to continue to dance ballet. A 14-year-old male basketball player comes in with acute lateral foot pain in his right foot. Currently on crutches, the player says the pain occurred two days ago after he landed on another player’s foot and twisted his ankle. A 22-year-old female ballet dancer complains of lateral foot pain that prevents her from rehearsing or performing regularly. She reports no history of trauma but a gradual onset of this pain, which persisted for two years in spite of treatment with physical therapy, nonsteroidal antiinflammatory medications and cortisone injections. What do all these athletes have in common? They all suffer from the same but poorly recognized condition: cuboid subluxation or cuboid syndrome. What Causes Cuboid Subluxation? While the inversion sprain is one of the most traumatic injuries to the lower extremity, a less recognized condition (and often a sequalae of an inversion stress at the ankle) is injury to the joints and ligaments around the tarsal cuboid, resulting in cuboid subluxation. Cuboid syndrome is a common cause of lateral foot pain in the athletic population and is often misdiagnosed or mistreated. It is usually defined as a minor disruption or subluxation of the structural integrity of the calcaneocuboid portion of the midtarsal joint. There are many synonyms for this condition including: lateral plantar neuritis, cuboid fault syndrome, dropped cuboid, locked cuboid and subluxed cuboid. An athlete with a cuboid subluxation will complain of lateral foot pain and weakness in push-off. The pain often radiates to the plantar aspect of the medial foot, the anterior ankle joint or distally along the fourth ray. This condition is common in ballet dancers and usually occurs acutely in male dancers when they land from jumps. Female dancers develop cuboid subluxation as an overuse syndrome from repetitive pointe work. Moving from foot flat to demi pointe initially creates a dorsiflexion moment on the midfoot, which changes to a plantarflexion moment while the foot moves to pointe. Again, the force reverses to a dorsiflexion moment while the foot returns to a flat position. The repetitive forces gradually decrease the stability of the midfoot and predispose some dancers to cuboid syndrome. The dancer will often complain of his or her inability to “work through the foot” while moving from this position of a flat foot to demi-pointe or a full point position. What One Should Look For In The Physical Exam When examining the affected foot of these patients, one can elicit pain by pressing dorsally on the plantar surface of the cuboid. Clinicians will find the cuboid’s minimal dorsal/plantar joint play is markedly reduced or absent when one compares it to the uninvolved foot. Severely subluxed cuboids can leave a shallow, visible depression on the dorsum of the cuboid and a fullness on the plantar aspect. Be aware that diagnosing cuboid syndrome via radiographs, computerized axial tomography (CT) scans or magnetic resonance imaging (MRI) is difficult because of the normal variations that exist between the cuboid and its surrounding structures, and the minimal amount of subluxation that is usually present. The term “locked cuboid” may more accurately describe this condition. As this term suggests, a small subluxation can markedly reduce the normal motion in the midtarsal joint, thus altering both the normal mechanics and the relationship between the rearfoot and the forefoot. The plantar displacement of the cuboid resulting in cuboid syndrome is most often reported in association with an inversion and plantarflexion stress of the ankle. It has been proposed that the mechanism of injury resulting in this isolated dislocation of the cuboid is due to rotation with associated inversion or eversion of the forefoot. The ligamentous disruption results in displacement of the cuboid. The peroneus longus tendon that travels in the groove on the inferior surface of the cuboid exerts a dorsal and lateral force on the forefoot.