Cuboid fractures

Understanding cuboid fracture

The cuboid fracture is a fracture affecting the cuboid bone, one of the bones of the foot located in the tarsal region, which articulates with the calcaneus behind, forming the calcaneo-cuboid joint, and with the 4th and 5th metatarsals in front, forming the so-called lateral Lisfranc joint. The calcaneo-cuboid and cubo-metatarsal joints, along with the bases of the 4th and 5th metatarsals, form the calcaneal foot, or weight-bearing foot.

Concept of the calcaneal foot

The study of muscular activity (electromyography) shows that the foot can support several times the body weight without intervention from its muscular strength. It therefore has passive systems to withstand the load. These are, in "mechanical equivalents," the composite beam, the arch, and the truss or, more precisely, the bow. This involves the coupling of a rigid element capable of enduring compression stresses (the bony chain) with a soft tissue element capable of controlling tension stresses. These soft tissue elements are fibrous (ligament, aponeurosis) and contractile (muscle).

These latter elements are generally arranged around the osteoarticular chain in several layers. The external or lateral part of the foot provides a solid support base on the ground: this is the calcaneal or weight-bearing foot. This edge or external arch, flat and muscular, includes ten bones: the three phalanges of the last two toes, the fourth and fifth metatarsals, the cuboid, and the calcaneus, which fills out the heel.

On the joint level, the calcaneal foot is remarkable for the calcaneo-cuboid joint, which has a saddle shape and the characteristic of reversing movements. This is fundamental because, in support, the inclination of the heel to one side induces the inclination of the forefoot to the other, which changes the step of the helix. The mobility of the calcaneo-cuboid joint is low, around eight degrees.

The calcaneo-cuboid joint is supported by a powerful plantar ligament, including a longitudinal one that extends forward to the bases of the third, fourth, and fifth metatarsals, explaining the difficulties of healing Jones fractures at the metaphyseal-diaphyseal junction of the fifth metatarsal.

The joints between the distal part of the cuboid and the base of the fourth and fifth metatarsals are arthrodial and form the lateral Lisfranc joint. Their main axis is oblique downward toward the sole, allowing for oblique mobility:

• Bringing the fourth and fifth metatarsals together tightly, toward the axis of the second metatarsal during plantar flexion,
• Separating them in dorsal flexion, which is relatively significant, nine degrees for the cubo-M5 and ten to eleven degrees for the cubo-M4. The ligaments are mainly developed on the sole, and the two metatarsals are joined at their base by an interosseous ligament and at their end by the intermetatarsal ligament.

On the muscular level, the calcaneal foot gives direct attachment to two muscles:

• The powerful triceps surae, which comes from the posterior compartment of the leg and is anchored on the posterior tuberosity of the calcaneus, and whose fibers extend onto the large plantar aponeurosis to form the Achilles-calcaneus-plantar supportive and propulsive system.
• The short fibular muscle or short peroneal, which anchors the lateral side of the leg onto the large base of the fifth metatarsal. It is a powerful everter of the foot. When the foot is fixed on the ground, it helps slow the advance of the leg while controlling its medial rotation.
• Sometimes a third muscle, called the third peroneal or accessory fibular, attaches to the fifth metatarsal.

An extremely important functional concept to highlight is that the calcaneal foot allows the redirection of the path of three muscles destined for the astragalar or talar foot, the propulsive foot. These muscles will thus take support on this stable lateral part of the foot to activate the medial propulsive lever. These muscles are:

• The long fibular, or peroneus longus, which passes under the cuboid and may occasionally develop an intratendinous ossicle at this level. This can sometimes be the cause of a painful pathology.
• The long flexor of the hallux, and the long flexor of the toes. The long flexor of the hallux originates from the upper and posterior part of the leg and passes under the sustentaculum tali, a bony protuberance on the medial side of the calcaneus. The contraction of the long flexor of the hallux tends to push the sustentaculum tali upwards and thus tilt the calcaneus outwards (in varus), which results in the twisting of the foot into inversion. This sustentaculum tali also supports the head of the talus, shifted inward due to the deviation of the neck of this bone (declination angle).

The calcaneal foot is also characterized by a fleshy muscular part represented by the intrinsic muscles, three in total, located on the plantar side.

The lower part of the posterior tuberosity of the calcaneus gives attachment to the thick plantar aponeurosis, which links it to the bases of the proximal phalanges of the toes. This aponeurotic band is hardly stretchable and corresponds to the tie beam of a truss or the string of a bow, which prevents its two points of attachment from moving apart. It is put under tension by dorsiflexion of the toes. The upper or dorsal surface of this aponeurosis provides attachment to the fleshy fibers of the intrinsic short flexor of the toes. Just before, the small muscle known as the quadratus plantae (Sylvius’ square muscle) attaches, joining the posterior aspect of the long flexor tendon of the toes to align the pull force with the axis of the foot. Part of the short flexor of the toes also attaches to the calcaneus below the quadratus plantae. The abductor hallucis attaches to the medial part of the posterior tuberosity. On the upper part of the anterior tuberosity of the calcaneus attaches the short extensor of the toes or pedious muscle, except for the fifth toe, which does not have one.

Finally, on the floor of the tarsal sinus attach the slings of the retinacular system, which anchor and control the extensor tendons.

This explains the role of the muscles in the composite bone-muscle beam system as well as in the osteoarticular-muscle chain. This foot, with a low arch, can thus withstand permanent loads during standing and walking. These intrinsic muscles mainly act as joint "lockers" and as stiffeners of the lever arms.

It is remarkable that the calcaneal foot, whose arch is not very pronounced, has no articular connection with the leg, but it does provide attachment to the powerful fibulo-calcaneal bundle, which forms the posterior part of the lateral collateral ligament, commonly called the external lateral ankle ligament.

This part of the foot thus only has a ligamentous connection with the fibula, but this fibula is very important for the functioning of the foot and has been called the "true bone of the foot" by the anatomist and surgeon Destot. Repair of bone and ligament injuries must always be careful and precise.

Causes and risk factors

The causes of cuboid fracture can be varied, but here are the most common:

• Direct trauma: Falls, blows, or sports accidents can cause a fracture.
• Twisting movements: Twisting motions, such as foot inversion, can be the origin of this type of injury.
• Repetitive stress: Activities that produce repeated impacts on the foot, like running or certain sports, can weaken the bone and lead to a stress fracture, also called an insufficiency fracture.

The risk factors associated with this fracture include:

• History of trauma: If you have a history of ankle sprain or foot sprain with associated laxity and proprioception issues, you may be more at risk for this type of fracture.
• Osteopenia or osteoporosis: Low bone mineralization can increase the risk of fractures.
• Inappropriate footwear: Wearing poorly fitting or inappropriate shoes for certain activities can also contribute to this problem.

Recognizing these potential risks and taking a few precautions can really help reduce the risk of cuboid fracture.

Symptoms to recognize

If you are suffering from a cuboid fracture, the first sign you may feel is intenseand exquisite pain when pressing on the cuboid. This pain is often accompanied by swelling and bruising that makes it difficult to wear shoes or even walk. Here are some common symptoms to watch for:

• Sharp pain when you press on your foot.
• A sensation of warmth or discomfort in the injured area.
• Swelling that can spread to other parts of your foot.
• Bruising of the foot is typical in case of a cuboid fracture.

Movement difficulties

Another symptom to be aware of is difficulty moving the foot or ankle. This limitation is usually caused by pain and instability related to the fracture. You may notice:

• An inability to put weight on the injured foot.
• Restrictions in your flexion and extension movements.
• Pain that increases with uneven ground.

These symptoms deserve your full attention, as identifying them quickly allows for appropriate management. Do not hesitate to consult promptly in case of functional impairment with foot bruising after a trauma, even if the trauma does not seem spectacular to you. Cuboid fractures can be diagnosed late or at the sequelae stage if there is no early consultation.

Diagnosis of cuboid fracture

The diagnosis of cuboid fracture often begins with a thorough physical examination. At this stage, the healthcare professional will :

• Assess the pain by palpating the cuboid.
• Look for any swelling or bruising around the ankle.
• Test foot mobility to identify possible movement limitations.
• Gather the patient's medical history, paying special attention to recent injuries.

This clinical information plays an important role in making a preliminary diagnosis and guiding further examinations.

Medical imaging

To confirm the diagnosis and guide the therapeutic strategy, it is necessary to use medical imaging techniques. The most commonly used methods include :

• Weight-bearing X-rays if possible : These are the first step for visualizing fractures and bone avulsions, including those of the cuboid.
• MRI : Magnetic resonance imaging helps detect more subtle injuries, such as stress fractures, also known as fatigue fractures or insufficiency fractures.
• CT scan : The CT scan allows for detailed analysis of the bone structure and gives specifics about the fracture : displacement, comminution, articular splits, and analysis of joint congruence.

Using these techniques helps doctors make a precise diagnosis and determine the best approach for treating the patient.

Available treatments

When treating a cuboid fracture, the conservative, non-surgical option can be suggested, especially if the fracture is stable and the joint congruence is preserved. These approaches aim to relieve pain and promote bone healing without having to undergo surgery. Here are some of the most common methods:

• Immobilization: Casts or walking boots are used to keep the foot at rest and well stabilized.
• Rest: It is important to avoid activities that could put too much pressure on the injured foot.
• Ice application: Applying ice to the affected area helps reduce swelling and soothe the pain.
• Anti-inflammatory medication: These medications may be prescribed to relieve pain and decrease inflammation.
• Painkillers: Pain management is essential, as it helps reduce the risk of algodystrophy.
• Anticoagulant treatment: Any injury or immobilization that prevents the patient from bearing weight on the injured side and walking normally requires the initiation of anticoagulant treatment to prevent the risk of thrombophlebitis.

Surgical treatment

In the case of a displaced fracture, surgical intervention may be necessary. The orthopedic surgeon plays a key role here, as they assess the situation and suggest the best treatment options. Surgical treatment of cuboid fractures is performed using the traditional open surgical technique. Several surgical procedures may be carried out:

• Open reduction and internal fixation: This procedure consists of reducing the fracture, restoring articular congruence, and stabilizing the fixation with surgical hardware, such as plates or screws.
• Bone graft: In the case of comminuted fractures or fractures with crushing of the spongy bone, a bone graft can be used to promote bone healing by restoring the length of the cuboid and joint congruence.
• Calcaneo-cuboid arthrodesis: In cases of major comminution, or associated calcaneus fracture, a calcaneo-cuboid fusion can be performed as a first-line treatment. The aim is to achieve fusion between the calcaneus and cuboid.
• Cuboid-metatarsal arthroplasties: In cases of cuboid fracture sequelae with cuboid-metatarsal joint injury, spherical pyrocarbon arthroplasty helps preserve adaptive mobility at the level of the lateral Lisfranc joints.

Do not hesitate to discuss with your doctor the risks and benefits associated with these surgical options. The decision to proceed with an operation depends on several factors, such as the severity of the fracture and your overall health status. By being well informed, you will be able to make enlightened decisions about your treatment.

Rehabilitation and recovery

Rehabilitation after a cuboid fracture is a key moment for regaining proper foot function and avoiding possible complications, especially joint stiffness. By following a well-designed rehabilitation program, you will be able to:

• Regain good mobility and stability in your foot.
• Strengthen the stabilizing muscles of your foot and ankle.
• Avoid joint stiffness.
• Optimize your functional recovery.

It is important to start rehabilitation as soon as your doctor gives you the green light. Taking a proactive approach can truly make a difference in your recovery journey.

Recommended exercises

To support your recovery after a cuboid fracture, specific exercises are essential. Here are some activities you could include:

• Posterior muscle chain stretching: These exercises help maintain your flexibility and limit joint strain on the ankle and foot.
• Muscle strengthening: Using resistance bands is an excellent way to work the muscles of your foot and ankle.
• Single-leg balance: This exercise is perfect for improving your stability and coordination.
• Progressive return to sports: Start with short distances and gradually increase. This will allow your foot to adapt smoothly.
• Proprioception exercises: Working on an unstable cushion or uneven surface strengthens your stabilizing muscles and enhances your balance.

Don't hesitate to consult a healthcare professional before starting any exercise program to ensure the chosen activities are suitable for your situation.