Cuboid fault syndrome, dropped cuboid, lateral plantar neuritis, locked cuboid, subluxed cuboid.
What is a Cuboid Syndrome?
The cuboid is a small bone on the outer edge of the foot between the calcaneus (heel bone) and the fifth metatarsal (the long bone on the outside of the foot that connects to the little toe). It gives stability to the side-to-side portion of a foot’s arch by acting as a pulley for a tendon coming from the peroneus longus muscle on the outside part of the leg that passes down the outside of the ankle joint, then under the cuboid where it changes direction and passes to the other side of the foot. Normally, the cuboid glides to increase the leverage of the peroneus longus, which contracts to improve the stability as the sole of the foot turns outward so that the inner edge of the foot bears the weight (pronate).
This makes the cuboid bone crucial for normal foot function, since it has to be very stable when the peroneus longus contracts. Otherwise, the contraction will cause its tendon to move the cuboid bone and strain the joints around it, resulting in a disruption or the cuboid slipping out of position (subluxation), crippling the entire “pulley system” and impairing the foot.
Cuboid syndrome refers to the painful condition when the foot overpronates and makes the peroneus longus overwork, pulling the cuboid (or any of the joints and ligaments in the vicinity) with much more force than usual and possibly out of place. This condition usually causes side-to-side (lateral) or outer-part pain in the foot, sometimes general foot weakness, as the disruption irritates the surrounding soft tissue structures attached to the cuboid. It is known as a “runner’s injury” because the repetitive foot-to-ground impact — like in running — greatly increases the chance of straining the cuboid.
What Causes a Cuboid Syndrome?
A person may develop cuboid syndrome through either a single injury event or repetitive strain over time. Excessive inward turn of an ankle (like an ankle sprain) or overflexing your foot or toes downward when moving is thought to be the most common cause. Repetitive micro-trauma to the ligaments attaching to the cuboid bone, as female ballet dancers are prone to by dancing on their toes, puts a person at risk for developing cuboid syndrome as well. A person’s foot type, such as the tendency to overpronate or underpronate, may also play a factor in the condition.
Who Gets a Cuboid Syndrome?
Cuboid syndrome affects mainly athletes, in particular those whose activities incur a significant amount of pressure on their feet from jumping (ballet, for example) or side-to-side movement (e.g., tennis and basketball). Male ballet dancers are very susceptible to this injury due to repetitive jumps.
Those with certain foot types, such as a flat or pronated foot, are much more likely to encounter this problem, especially when they run regularly and/or wear unsupportive shoes. Someone who abnormally pronantes the foot while pushing it off the ground causes an increase in force that is transferred to the cuboid bone, which leads to instability and a resultant injury.
What are the Symptoms of a Cuboid Syndrome?
A common symptom of cuboid syndrome is an ache on the outside of the foot that gets worse with running or jogging. Some also feel a vague weakness in the foot, especially when trying to push off the ground or landing from a jump.
Whatever the cause, the symptom pattern is very similar:
- Patients typically complain of pain that develops rapidly or in some cases gradually after a considerable period of time following an ankle sprain.
- Pain is usually right over the cuboid bone, but can also travel underneath the foot into the arch.
- You may also experience pain in the surrounding structures, both with weight on and off, though it is more difficult for you to walk, nevertheless.
- The lateral side of the foot will show swelling, may be black and blue (ecchymosis), perhaps with some redness present as well — all signs of inflammation.
- Many patients will significantly overpronate (feet roll in or flatten).
How do You Diagnose a Cuboid Syndrome?
Carefully and slowly stand on your toes or roll the arches of your foot. These motions tend to exercise the foot’s cuboid joints and ligaments. If you feel pain in the outer edge of the foot and specifically the cuboid area, you may have cuboid syndrome.
A doctor will ask you about the symptoms, injury
The diagnosis of cuboid syndrome cannot be definitively confirmed by x-ray or MRI (magnetic resonance imaging) because the subluxation is so minor that imaging studies would be of little value. However, doing so will rule out other conditions, particularly bone fracture.
How do You Treat a Cuboid Syndrome?
Thankfully, cuboid syndrome responds well to conservative treatment. In many instances relief from pain is instantaneous. Treatment aims at “putting the cuboid back in place” with physical manipulation, augmented by physical therapy, strapping and padding. A foot orthotic with a built-in cuboid pad can also be very helpful in maintaining the cuboid.
The most common initial treatment of this condition is to use some type of strapping to stabilize the bone so it can be an effective pulley for the tendon again. Some may need pain relief or anti-inflammatory medication, and ice application if there is a lot of swelling.
Self-Care at Home
The application of RICE is common in the treatment of cuboid syndrome. RICE is the acronym standing for rest, ice, compression and elevation:
1. Rest: Rest your foot by not walking on it. The first 24-48 hours after the injury is critical for treatment and you must quit physical activities. Gradually put as much weight on the affected foot as tolerated, and don’t use crutch if/when you can walk with minimal to no pain or limp.
2. Ice: Cover the area with ice or apply cold compresses. For the first 48 hours after the injury, do this to an elevated ankle for about 20 minutes, three or four times a day. The ice pack can be a bag of frozen peas or corn so you can re-use it. Do NOT ice an ankle sprain for more than 20 minutes at a time, as the cold can damage the tissues. Also, if you’re elderly or have poor circulation, remove the ice pack from the injured part for 30 seconds or so every five minutes.
3. Compression: Use dressings, bandages, or ace-wraps to immobilize and support the injured ankle when elevating the sprain in early treatment. Wrap the foot from toes all the way up to the top of the calf muscle, overlapping the elastic wrap by one-half of the wrap’s width. The wrap should be snug, but not cutting off circulation to the foot and ankle. Re-wrap if your foot becomes cold, blue, or numb!
4. Elevate: Keep your foot higher than your heart as often as possible for 48 hours. Sit in a reclining chair or prop your legs up with pillows. Elevate at night by placing books under the foot of your mattresses — just make sure you stand up slowly in the morning.
Additionally, strengthen your foot and ankle through exercises upon doctor’s approval to re-introduce them to the normal function and re-train them to respond properly.
A medical professional can treat the syndrome by realigning (also known as reducing) the cuboid. This form of manual manipulation of the foot should be done by a trained specialist, such as a podiatrist or physical therapist. After the manipulation, the specialist will reassess your condition to determine the effectiveness and functional level. Often, you will experience complete relief of symptoms with a successful reduction.
A common manipulation is known as the “Black snake heel whip,” an original technique described by Newell and Woodle that has since been modified. The specialist interlocks his/her fingers over the sole of the foot while placing the thumbs on the middle surface of the cuboid. With the patient’s knee stretched in 70- to 90-degree angle, the specialist flexes the ankle and turns the sole slightly inward, followed by a thrust with both thumbs directly on the cuboid.
Afterward, the specialist will likely use a cuboid pad, usually made of a quarter-inch-thick felt, placed directly under the cuboid bone in conjunction with a low-dye taping to maintain the cuboid reduction and provide the arch with additional support.
A treatment procedure commonly also includes physical therapy, up to twice a week for six weeks; strapping, twice a week for six weeks; cortisone injection for anti-inflammatory purpose, three times weekly; orthotics; and anti-inflammatory medications.
Because cuboid syndrome is generally quite treatable and most patients return to a normal level of activity once the pain is brought under control, surgery is a rarity used only when conservative treatments fail to work. There are three surgical options, all of which deals with stabilization of the joint.
The first procedure choice is an arthroscopy of the cuboid-calcaneus joint, using an arthroscopic shrinkage device usually used in shoulder stabilization. This procedure is fairly simple to perform. The patient will be in a cast with absolute nonweight-bearing on the foot for two months afterward.
The second option is transplanting a fresh, frozen tendon from a cadaver to the said joint. It is a weave-type procedure in which the surgeon weaves a tendon about the lateral joint so it can serve as ligament-like stabilizer of that joint.
The third and most definitive alternative is a fusion of the cuboid-calcaneus joint. This is not a very difficult procedure and does not cause much stiffness or loss of function of the foot or ankle. A rigid internal or external fusion is essential, however, since the rate of non-union is high in this joint when compared with other rear-foot fusions due to the cuboid’s increased motion.
How to Prevent a Cuboid Syndrome?
As overpronation and underpronation are both major causes, be aware of how your feet move when you walk. Constantly remind yourself to adjust excessive motions in either direction and train yourself to walk properly.
Warm up before doing exercises and vigorous activities.
Wear the right shoes when running. Bad fitting and unsupportive shoes can cause cuboid syndrome and other foot disorders.
Stop any activity that causes pain in the foot immediately. Pain is a sign that something is wrong. Give your foot a break before testing it again. If it still hurts, stop and see a doctor.
Strengthening and endurance exercises for the leg and foot muscles, along with hamstring stretches, for about 5 minutes almost daily can condition the body to the proper workings of the “pulley system,” therefore reducing the chance of disruption.