Sesamoid bones are located in the knee joint, ankle joint, hand and foot. They are small, often break and the tissue around them becomes inflamed.
The knee joint, where the sesamoid bone (the patella) is the largest and most complex joint, bears a lot of load. The knee often suffers from injuries and damage.
In the hand, the sesamoid bones are located on the palmar surface. In traumatology, the most common fractures of the hand are accompanied by pain, swelling, and loss of performance. In the foot, the sesamoid bones play a large role in varying loads on the foot. Often after excessive exercise we experience pain in the foot. This is called sesamoiditis.
Problems can be avoided if you do not overload your joints and give them rest, do exercises for joint health, and wear comfortable and high-quality shoes.
Most of the bones in human body connected to each other through joints. However, there are also bones that do not directly articulate with other bones. Instead, they are located deep within the muscles or tendons. Such bones are called sesamoids. The largest of them is the patella (kneecap). Two others, much smaller (the size of a corn grain), are located on the lower surface of the forefoot at the base of 1 toe, one on the outside, the other on the inside.
Sesamoid bones are intercalary bones that are closely connected to the joint capsule and surrounding muscle tendons. One of their surfaces is covered with hyaline cartilage and faces the joint cavity.
Intercalated bones help reduce the joint cavity and indirectly increase the range of motion in it. They also act as blocks for the tendons of the muscles acting on the joint.
Interesting to know! The largest sesamoid bone is the patella. Small sesamoid bones are often found in the joints of the hand, foot (in the interphalangeal, carpometacarpal joint of the 1st finger, etc.)
Sesamoid bones act as blocks. They form a smooth surface along which the tendon slides, increasing the moment of force developed by the corresponding muscle. The sesamoid bones in the forefoot area are also involved in distributing the load exerted by the body weight when walking and are involved in the movements of 1 toe.
Where are they located?
Sesamoid bones can be located in the area of any joints, including:
- knee joint - patella (in the thickness of the quadriceps tendon);
- hand - two sesamoid bones located in the distal parts of the first metacarpal bone. There is usually also a sesamoid bone in the distal portion of the second metacarpal. The pisiform bone of the wrist is also, in fact, a sesamoid, located in the tendon of the flexor carpi ulnaris.
- foot - two sesamoid bones in the area where the first metatarsal bone joins the first toe (inside the tendon of the flexor hallucis brevis).
All sesamoid bones, as well as all processes of bones, increase the leverage of the muscles that are attached to them.
Diseases of the sesamoid bones
Like other bones, these ossicles can be subject to fractures. In addition, problems here can also arise with the tendon surrounding them. This condition is called sesamoiditis and is considered a type of tendonitis. It can often be found in ballet dancers, runners and baseball players.
General symptoms abnormalities in the bones:
- Pain localized under the first toe on the plantar surface of the foot. With sesamoiditis, pain may develop gradually, while with a fracture, pain occurs immediately after the injury.
- Swelling and hemorrhages, which may not exist.
- You may also experience painful sensations and difficulty bending and straightening 1 finger.
Important! The sesamoid bones of the feet are most often affected by pathologies.
Although these bones are very small in size, they play a big role when walking, jumping, running and other loads on the foot. When the sesamoid bones are involved in one of the pathological processes, they become a source of very severe pain, which significantly worsens the patient’s quality of life.
Diagnosis of pathologies
During a clinical examination, the doctor will specifically examine the sesamoid bones for tenderness in this area. The doctor may also carefully evaluate the movements of 1 finger and ask you to bend and straighten it. When dorsiflexing 1 finger, you may notice increased pain.
To make a diagnosis, your doctor will order an x-ray. For many people, the sesamoid bone located toward the center of the foot (the medial sesamoid bone) consists of two parts. The edges of such fragments of sesamoid bone are usually smooth, whereas the edges of the fragments during a fracture are sharp, jagged, so radiography usually makes it possible to make the correct diagnosis.
To compare bone architecture, your doctor may also order x-rays of your opposite foot. If there are no changes on radiographs, the doctor may prescribe scintigraphy
Sesamoiditis
Sesamoiditis is an inflammation of the area under the first metatarsal head of the big toe joint.
Its reasons may be:
- valgus deformity, “opening” the sesamoid bones;
- activities that place additional pressure on this area;
- injury.
For example, if a person with a hallux valgus deformity plays tennis, which involves a lot of running with a sharp start and a sudden stop, and the load on the certain part feet, it irritates the sesamoid bones.
The same can be said for women with a similar deformity who wear high-heeled shoes. The inflammation may appear just under the sesamoid bone or between it and the overlying metatarsal bone. In the latter case, the cartilage between these two bones is injured, and after a few years it wears out to the point that the bones rub against each other.
Important! If you feel significant pain when you palpate the area under your thumb joint, you are an excellent candidate for this diagnosis. Discomfort is explained by capsulitis or synovitis of the metatarsophalangeal joint and is aggravated by wearing uncomfortable shoes, in particular high heels.
The pain begins gradually and becomes unbearable over time. In some cases, numbness is felt due to the proximity of the corresponding nerve, which in turn becomes inflamed due to sesamoiditis.
It is often difficult to determine whether the problem is sesamoiditis or a sesamoid fracture. As a rule, with a fracture, the swelling is more pronounced, and the pain comes suddenly and varies in intensity.
Treatment of sesamoid bone diseases
Treatment of injuries and diseases of the sesamoid bones is usually conservative. However, if this treatment is ineffective, you may be advised to undergo surgery to remove the sesamoid bone.
For sesamoiditis, the following measures are resorted to:
- Stopping those types of activities physical activity, which lead to increased pain syndrome.
- Taking Aspirin or Ibuprofen for pain relief.
- Rest and application of ice to the plantar surface of the foot. Do not apply ice directly to the skin. It is better to use an ice pack or wrap the ice in a towel.
- Wearing shoes with soft soles and low heels. Wearing shoes with hard soles can also be more comfortable.
- Using a soft shock-absorbing pad to relieve the sesamoid bones.
- Return to physical activity should be gradual, while continuing to use shock-absorbing pads made of dense foam rubber.
Important! Activities that place stress on the forefoot should still be avoided.
- Taping 1 finger to give and hold it in a position of some plantar flexion.
- To reduce swelling and inflammation, your doctor may recommend a local injection of glucocorticoid.
- If the symptoms of the disease persist, the doctor may recommend immobilizing the foot with a removable splint, as for a fracture, for a period of 4-6 weeks.
For a fracture of the sesamoid bone:
- Wearing shoes with hard soles or immobilization with a short splint.
- Taping of 1 metatarsophalangeal joint to limit the movements of 1 finger.
- To relieve the sesamoid bones while the fracture heals, you may be advised to wear a special “J” shaped pad.
- You may also be advised to take painkillers such as aspirin or ibuprofen.
- Discomfort after a sesamoid bone fracture can persist for up to several months.
- Often, various shock-absorbing pads and other orthopedic devices are used during the healing period of a fracture.
The most complete answers to questions on the topic: "sesamoid bone knee joint treatment".
Sesamoiditis is one of the most common diseases of dancers and athletes. The essence of the pathology is that in the sesamoid bones, which are located inside the tendons, for one reason or another, an inflammatory process begins to develop.
Most often, this disease affects the sesamoid bones of the first toe, because when walking, dancing, playing sports, especially running, a person relies on them. Therefore, strong and constant physical activity can lead to injury. Even though these dice are no larger than the size of a pea, they play great value in a person's comfortable walking.
Causes
Sesamoiditis of the first toe most often occurs in young people, especially if they prefer to play sports or dance. Therefore, the main cause of the disease can be considered excessive physical stress on the legs without proper rest and alternation of rest modes and sports or dancing.
However, pathology cannot appear overnight. To do this, a certain amount of time must pass and certain conditions must coincide. And the main one is the thinning of the subcutaneous fat layer on the sole of the foot. As soon as this happens, the disease itself gradually begins to develop due to the fact that the sesamoid bones bear an additional heavy load.
However, inflammation is only one half of the problem. If you continue to neglect your health, a fracture of these bones may occur, which almost never heals, and in order to return the legs to their former ease when walking, surgical intervention is necessary.
Sesamoiditis often coexists with another disease - foot valgus deformity of the first toe. This is especially true for women. Therefore, if you have this diagnosis, it is necessary to more carefully monitor the health of your legs and try to get rid of this problem so as not to get inflammation of the sesamoid bones.
More articles: Is it harmful to give injections to the knee joint?
Symptoms
The main symptom of sesamoiditis is pain. Moreover, at the very beginning it is insignificant and few people pay attention to it. However, over time it intensifies and becomes almost unbearable.
The pain intensifies when wearing high-heeled shoes or tight and uncomfortable shoes. However, it is worth remembering that inflammation of these bones and their fracture have similar symptoms. True, with a fracture, more pronounced swelling occurs, and pain occurs suddenly during dancing or playing sports. Moreover, at this moment a person can even be wearing shoes without heels.
In some cases, patients may notice numbness of the first toe. This is very simple to explain. This phenomenon occurs when pathological process the nerve is involved. It begins to become inflamed because it is close to the bone itself.
Diagnostics
Diagnosis of the disease, as a rule, does not have any problems. This is done by examining the first toe and interviewing the patient. Sometimes x-rays or MRIs are performed.
If there is doubt about the diagnosis, a joint puncture is performed. This is necessary in order to distinguish inflammation of the sesamoid bones from pathologies such as gout or arthritis, which have almost the same symptoms.
Conservative treatment
Treatment of sesamoiditis is carried out at home and depends only on what caused the inflammation. If the inflammation appears due to hallux valgus, then wearing an individually selected shoe helps correct the abnormal position of the first toe. orthopedic shoes, and such treatment quickly leads to recovery without the use of medications.
If the cause is a sports injury, then the treatment is to apply ice to the site of inflammation or use ultrasound. In this case, the legs need rest and a certain period of time without sports training. Thanks to this simple treatment The pathology also goes away on its own. But in the future you need to treat your feet more carefully.
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If the disease progresses to chronic stage, then a cortisol injection, which is given directly into the inflamed joint, helps well. However, such injections can only be performed in a hospital setting.
As for the fracture, it is also clearly visible on an x-ray or MRI, however, in 20% of the entire population of the planet, the sesamoid bone is divided into two halves, so this feature is often considered a fracture. This means that only an experienced specialist should diagnose the disease.
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Sesamoid bones(from Latin Sesamum) - bones located in the thickness of tendons and usually lying on the surface of other bones. Sesamoids are noted in areas where tendons pass over joints (eg, wrist, knee, foot). The sesamoid bones provide protection to the tendons and keep the tendons some distance from the center of the joint, increasing the leverage of force.
The sesamoid bones are closely connected to the joint capsule and muscle tendons. One of their surfaces is covered with hyaline cartilage and faces the joint cavity.
In human anatomy
Sesamoid bones can be located in any joint area, including:
- knee joint - patella (in the thickness of the quadriceps tendon)
- hand - two sesamoid bones are located in the distal parts of the first metacarpal bone. There is usually also a sesamoid bone in the distal portion of the second metacarpal. The pisiform bone of the wrist is also, in fact, a sesamoid, located in the tendon of the flexor carpi ulnaris.
- foot - two sesamoid bones in the area where the first metatarsal bone joins the first toe (inside the tendon of the flexor hallucis brevis).
More articles: The joint of the little toe hurts
Diseases of the sesamoid bones
A common foot disease among dancers is sesamoiditis. There are also bifurcated sesamoid bones, which can be either congenital or post-traumatic.
If there is insufficient blood supply to the joint in which the sesamoid bone is located, it can also lead to tissue necrosis.
In addition, arthrosis of the joint is possible, most often observed in people with a high longitudinal arch of the foot. Consequence of this disease is the complete destruction of articular cartilage and sesamoid cartilage.
Notes
- Tim D. White Human Osteology, 2nd edition (San Diego: Academic Press, 2000), 199, 205.
- White, Human Osteology, 2nd edition, 257-261.
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Wed, 08/24/2016 – 02:09
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Hello.
Male, 31 years old, 185 cm, 85 kg. The lifestyle for the last 5 years has been sedentary. I do not smoke.
My left knee has been bothering me for half a year, it started hurting on the first day of a cold in February, and there is severe, tolerable pain when walking up the stairs. If you accidentally hit something with your left patella, it hurts; on the right, under the same conditions, it doesn’t hurt; when you palpate the left knee in a bent position on the front side, it hurts from the patella and below. Photo - without bone changes, ultrasound of the joints showed Becker cysts in the left joint. Rheumatoid factor, s- reactive protein, antistreptolysin O - all negative.
The rheumatologist diagnosed me in May with prearthrosis of the left knee joint.
I took Nise 2x100 for 14 days, Diaflex for 3 months.
Diagnosis orthopedist-traumatologist in June - periarthritis, suggested - Hi-Flex injections. Didn't give injections.
As a result, today on the left side there is pain when walking up the stairs, pain while standing, pain is tolerable when sitting.
Associated diseases - superficial gastritis, reflux esophagitis, heart problems (post-myocardial cardiosclerosis, ventricular extrasystole EI - 2.7%), neuralgia trigeminal nerve. There were no problems with bones and joints before.
The sesamoid bones in the forefoot area are involved in distributing the load exerted by the body weight when walking and are involved in the movements of 1 toe. Like other bones, these ossicles can be subject to fractures.
Most bones in the human body are connected to each other through joints. However, there are also bones that do not directly articulate with other bones. Instead, they are located deep within the muscles or tendons. Such bones are called sesamoids. The largest of them is the patella (kneecap). Two other, much smaller ones (the size of a corn grain), are located on the lower surface of the forefoot at the base of 1 toe, one on the outside, the other on the inside.
Sesamoid bones act as blocks. They form a smooth surface along which the tendon slides, increasing the moment of force developed by the corresponding muscle. The sesamoid bones in the forefoot area are also involved in distributing the load exerted by the body weight when walking and are involved in the movements of 1 toe. Like other bones, these ossicles can be subject to fractures. In addition, problems here can also arise with the tendon surrounding them. This condition is called sesamoiditis and is considered a type of tendonitis. It can often be found in ballet dancers, runners and baseball players.
- Pain localized under the first toe on the plantar surface of the foot. With sesamoiditis, pain may develop gradually, while with a fracture, pain occurs immediately after the injury.
- Swelling and hemorrhages, which may not exist.
- You may also experience pain and difficulty bending and straightening 1 finger.
During a clinical examination, the doctor will specifically examine the sesamoid bones for tenderness in this area. The doctor may also carefully evaluate the movements of 1 finger and ask you to bend and straighten it. When dorsiflexing 1 finger, you may notice increased pain.
To make a diagnosis, your doctor will order an x-ray. For many people, the sesamoid bone located toward the center of the foot (the medial sesamoid bone) consists of two parts. The edges of such fragments of sesamoid bone are usually smooth, whereas the edges of the fragments during a fracture are sharp, jagged, so radiography usually makes it possible to make the correct diagnosis. To compare bone architecture, your doctor may also order x-rays of your opposite foot. If there are no changes on the radiographs, the doctor may prescribe scintigraphy.
Treatment of injuries and diseases of the sesamoid bones is usually conservative. However, if this treatment is ineffective, you may be advised to undergo surgery to remove the sesamoid bone.
Sesamoiditis
- Stopping those types of physical activity that lead to increased pain
- Taking aspirin or ibuprofen for pain relief
- Rest and application of ice to the plantar surface of the foot. Do not apply ice directly to the skin. It is better to use an ice pack or wrap the ice in a towel.
- Wearing shoes with soft soles and low heels. Wearing shoes with hard soles can also be more comfortable.
- Using a soft shock-absorbing pad to relieve the sesamoid bones.
- Return to physical activity should be gradual and continued use of dense foam rubber pads. Activities that place stress on the forefoot should still be avoided.
- Taping 1 finger to give and hold it in a position of some plantar flexion.
- To reduce swelling and inflammation, your doctor may recommend a local injection of glucocorticoid.
- If the symptoms of the disease persist, the doctor may recommend immobilizing the foot with a removable splint, as for a fracture, for a period of 4-6 weeks.
Sesamoid fracture
- Wearing shoes with hard soles or immobilization with a short splint.
- Taping of 1 metatarsophalangeal joint to limit the movements of 1 finger.
- To relieve the sesamoid bones while the fracture heals, you may be advised to wear a special “J” shaped pad.
- You may also be advised to take painkillers such as aspirin or ibuprofen.
- Discomfort after a sesamoid bone fracture can persist for up to several months.
- Often, various shock-absorbing pads and other orthopedic devices are used during the healing period of a fracture.
- Bone base of the foot
- Ankle joint
- Other joints of the foot and their ligaments
- Foot muscle groups
- Neurovascular formations of the foot area
The foot is the lower anatomical part of the leg. In medical terminology, it is located most distally, that is, away from the center of the body or the place of attachment to the body. The skeleton of the foot is quite complex and ideally matches the function assigned to the human feet. They went through a long evolution to adapt to walking upright.
Bone base of the foot
On the foot, there are areas formed by certain bone groups: the tarsal metatarsus and the phalanges of the fingers.
The tarsus is the section of the foot located immediately below the ankle joint area. From above it is limited by a circular line drawn through the posterior edge of the heel bone along the lower edges of the ankles, which corresponds to upper limit human feet. The tarsus consists of seven spongy bones, which are arranged in two rows:
- The back row is the very part that is the main structure of the heel and consists of two relatively massive bones of a complex “irregular” shape: the talus and the calcaneus.
- The front row is divided into two more sections - the one located with inside the foot (medial) and the one located on the outer edge (lateral). The first includes three wedge-shaped bones and the scaphoid, which occupies an intermediate position between them and the head of the talus. The second is represented by the cuboid alone - it is located between the 4th and 5th metatarsal bones in front and the calcaneus in the back.
The metatarsus occupies an intermediate position among the three regions. Here the variety of sizes, shapes and names stops abruptly. It is built of five bones, which are very similar to those located in the metacarpus of the upper limb. They consist of several parts:
- grounds;
- bodies;
- heads.
The phalanges of the toes are the smallest of all the bones of the foot. Each finger is formed from three such bones, with the exception of the big one - the structure of the human foot is such that it contains only two phalanges. It is also called the first, it is from here that the numbering of the toes begins - from I to V.
In addition to the listed bones, there are also special sesamoid bones, which are small in size and serve to protect the tendons and increase their leverage. They can be located between the phalanges of the big toe, as well as in the area of the articulations of the metatarsus and phalanges.
Ankle joint
The anatomy of the human foot is rich in interosseous joints, which are mostly represented by joints - they are strengthened by ligaments. Before examining each individually, it is necessary to summarize general information about what a joint is. This is a synovial joint capable of participating in a wide variety of movements depending on its structure. It may contain the following articular elements:
- surfaces;
- cartilage;
- cavity;
- capsule;
- discs and menisci;
- lip.
It should be remembered that the joint is at the peak of development among all other interosseous joints; in the structure of the foot, one of them occupies a special position - it is of the largest size and is quite complex in structure. Ankle joint. It is so large and powerful that it has been isolated into a separate anatomical region - the “ankle joint area”. Formed from certain parts:
- The articular surfaces are formed by the tibial and fibula, their lower ends - they form a recess for the block of the talus, covering it from several sides. The block is also involved in the construction of the joint. There are 6 surfaces in total.
- Hyaline cartilage covers the outer parts of the connecting surfaces, preventing them from directly touching. It forms the joint space, defined on x-ray as the distance between the bones.
- The joint capsule is attached just along the edge of the cartilage and in front captures the area of the talus - its neck.
Do not forget about the presence of the ligamentous apparatus, which often accompanies interosseous joints. The ankle joint is strengthened by the medial and lateral auxiliary ligaments. The first resembles the letter delta from the Greek alphabet: it is attached above to the inner malleolus, below - to the navicular, talus and calcaneus. The second one comes from the outer ankle, diverging in three directions, forming ligaments.
This joint is defined as a trochlear joint: it moves around the frontal axis; only when flexed can the human “paw” make sideways movements.
Other joints of the foot and their ligaments
There are many movable joints directly between the bones of the human foot. In the tarsal region alone there are four:
- Subtalar joint. It has a cylindrical shape and limited mobility. The joint is supported by three connective tissue cords. Differs in functional integrity from a clinical point of view.
- The talocaleonavicular joint is considered a ball-and-socket joint, but is only movable in one sagittal plane around its axis.
- The calcaneocuboid joint is involved in motor activity the two above. Together with the previous joint, it is called the “transverse tarsal joint.” It is surrounded by two ligaments, which are a continuation of the so-called bifurcated ligament. It is considered the “key” of the joint, since it must be cut in order to gain full access to it.
- Wedge-navicular joint. It is easy to guess what articular surfaces it consists of - all three sphenoid bones take part in their formation in front. The synovial joint is strengthened by several groups of tarsal ligaments.
The anatomy of the foot is complex and diverse. In addition to the above joints of the lower part of the human leg, there are five tarsometatarsal, metatarsophalangeal and interphalangeal joints. The latter does not necessarily have to be present in the area of the fifth finger, since the middle and distal phalanx of this finger can be fused. There are also intermetatarsal joints, strengthened by the dorsal, interosseous and plantar ligaments of the metatarsus. The ligamentous and articular apparatus of the foot must be protected, since each of its elements performs a specific function that ensures the most comfortable movement in this area.
Foot muscle groups
The structure of the foot, as is known, is not limited to the skeleton. The muscular composition of the human foot area, like the articular one, is very diverse.
The table shows the muscles and their groups that descend from the lower leg to the foot.
| Group | Muscle name | Function (for foot movement) |
| Front | Extensor pollicis longus | Extension of the big toe, as well as the foot as a whole, while raising its inner edge |
| Extensor digitorum longus | Participates in extension, elevation of the outer edge, abduction to the side | |
| Anterior tibial | Extension, raises the inner edge | |
| Lateral | Long fibula | Pronation, abduction, flexion |
| Short fibular | ||
| Rear | ||
| Surface layer | Forms the Achilles tendon | Motor activity of the ankle joint |
| Deep layer | Flexor digitorum longus | Supination and flexion |
| Posterior tibial | Adduction and flexion | |
| Flexor hallucis longus | Can bend not only the first finger, but also play a role in bending others |
Considering the serious functional role of the foot, it is easy to assume that in addition to the above-mentioned tendons attached to its bones, there are short muscles by analogy with upper limbs. The structure of the human foot suggests the presence of certain groups:
- lateral;
- average;
- dorsal muscles;
- plantar muscles.
It is important to remember that anatomical terminology is structured in such a way that often the very name of the muscle contains its function. Often movements are carried out by several of them at once. If one muscle is damaged, its role can be partially compensated by another that performs a similar function.
Neurovascular formations of the foot area
In humans, the body is structured in such a way that often blood vessels and nerves extend throughout the body, accompanying each other. Such relationships came to be called neurovascular bundles. They are located in almost every region.
Thus, the tibial bundle in front is represented by the following formations:
- anterior tibial artery;
- two anterior tibial veins;
- deep peroneal nerve.
When they move to the foot, their names change: dorsal artery of the foot, dorsal veins of the foot, and two dorsal digital nerves, respectively. Arterial vessel branches into many branches, supplying blood to different areas of the foot. The nerve is responsible only for the movement of the extensor digitorum brevis and the sensitivity of the skin of the sides of the fingers facing each other in the area of the first interdigital space. The skin of the remaining areas of the phalanges from the rear is innervated by the branches of the superficial peroneal nerve, coming from the side of the lateral muscles of the leg.
The posterior, so-called tibial bundle consists of certain components:
- posterior tibial artery;
- two veins of the same name;
- tibial nerve.
In the lower part of the leg, the artery gives off two branches: internal (medial) and external (lateral) plantar, which form two arterial arches. The tibial nerve gives off its branches to various areas of the sole, also directing one to the lateral side of the dorsum of the foot.
The complex structure of the human foot is accompanied by an equally intricate course of nerves.
Knowledge of the anatomy of the foot is necessary for a correct understanding of almost any pathology, one way or another, related to this area lower limb.
Tags: Bones, Treatment of joints
The talus bone consists of a head, neck and body. The head has an articular scaphoid surface (facies articularis navicularis) for articulation with the scaphoid bone. The upper surface of the body is represented by a block (trochlea) for articulation with the bones of the lower leg. On both sides of the block there are articular platforms - places of articulation with the medial and lateral ankles (facies articulares medialis et lateralis). On the lower surface of the body there is a deep groove (sulcus tali); in front and behind it there are articular platforms for articulation with the calcaneus (facies articulates calcaneae anterior, media et posterior) (Fig. 97).
97. Talus.
A - bottom view; B - rear view: 1 - trochlea tali; 2 - facies maleolaris lateralis; 3 - processus lateralis tali; 4 - processus posterior tali; 5 - facies articularis calcanea posterior; 6 - facies articularis calcanea media; 7 - facies malleolaris medialis; 8 - facies articularis calcanea anterior
Calcaneus
The calcaneus (calcaneus) on the upper surface contains three platforms (facies articulares talares anterior, media et posterior) for connection with the talus. The last two are separated by a groove (sulcus calcaneus). Together, when the groove of the calcaneus combines with the groove of the talus, the sinus tarsi (sinus tarsi) is formed, where there is an interosseous ligament. At the back, the bone passes into the calcaneal tuber (tuber calcanei), and in the anterior part of the bone there is a saddle-shaped articular surface (facies articularis cuboidea) for connection with the cuboid bone. On the medial side of the bone there is a protrusion - the support of the talus (sustentaculum tali) (Fig. 98).
98. Right calcaneus.
1 - facies articularis talaris posterior;
2 - tuber calcanei;
3 - sustentaculum tali;
4 - facies articularis talaris media;
5 - facies articularis talaris anterior;
6 - facies articularis cuboidea.
Scaphoid
The navicular bone (os naviculare) is located in the area of the inner edge of the foot, has a concave articular surface for the head of the talus and a convex one for connection with sphenoid bones. On its lower surface there is a pronounced tuberosity (tuberositas ossis navicularis)
Sphenoid bones
Three wedge-shaped bones (ossa cuneiformia) are arranged in a row, starting from the medial edge of the foot: os cuneiforme mediale, intermedium et laterale (Fig. 99).
Cuboid
The cuboid bone (os cuboideum) is located on the lateral edge of the foot. On its lower surface there is a tuberosity (tuberositas ossis cuboidei) and a notch (sulcus tendineus musculi peronei longi) from the pressure of the peroneus longus tendon (Fig. 99).
99. Bones of the right foot.
1 - calcaneus;
2 - talus;
3 - os cuboideum;
4 - os naviculare;
5 - os cuneiforme laterale;
6 - os cuneiforme intermedium;
7 - os cuneiforme mediale;
8 - os metatarsale 1;
9 - phalanx proximalis;
10 - phalanx media;
11 - phalanx distalis.
Metatarsus
The metatarsus consists of five metatarsal bones (ossa metatarsalia I-V). Its parts are distinguished: base (basis), body (corpus) and on distal end head. In the area of the base and head there are articular platforms. On the lower surface of the base of the first metatarsal bone and on the lateral surface of the base of the fifth bone there are tuberosities (tuberositas ossis matatarsalis I et V) (Fig. 99).
One sesamoid bone is adjacent to the lower lateral and medial surfaces of the heads of the first and fifth metatarsal bones.
Toe bones
The toes (digitorum pedis) consist of three phalanges (phalanges proximalis, media et distalis), which are much shorter than the phalanges of the fingers. Thumb the feet have two phalanges (phalanges proximalis et distalis), the rest have three. Each phalanx has a body and two ends: proximal - the base and distal - the head. At the distal end distal phalanx there is a tubercle (tuberositas phalangis distalis).
Ossification. All bones of the foot go through webbed, cartilaginous and bony stages of development. Ossification nuclei appear in the calcaneus at VI months, in the talus at VI-VII months, in the cuboid bone at IX months intrauterine development, in the medial sphenoid - in the 2nd year of life, in the sphenoid - in the 3rd year, in the sphenoid (lateral) - in the 1st year, in the scaphoid - in the 4th year. At the 3rd - 7th year of life, 1-2 independent ossification nuclei appear in the calcaneal tubercle, which in girls merge with the body of the calcaneus by 11-12 years, in boys - by 15 years.
In the phalanges of the toes, bone points are formed in the diaphysis of the phalanges in the 10-13th week of intrauterine development, in the proximal epiphysis in the 1st - 3rd year, and in the head of the metatarsal bones - in the 1st year.
Sesamoid bones
Sesamoid bones include those bones that are located in muscle tendons. The largest is the patella.
Sesamoid bones in the area of location of the 1st and 5th metatarsophalangeal joints occur in girls between 8-12 years, in boys - between 11-13 years. Similar bones also appear on the hand, most often in the first carpometacarpal joint.
Anomalies. Anomalies of the bones of the lower extremity include accessory, unstable bones of the foot. As a rule, there are about nine such bones: 1) bones between the medial and intermediate sphenoid bones; 2, 3) bones between the I and II metatarsal bones; 4) the bone located above the scaphoid; 5) the bone lying above the talus; 6) bone at the site where the tibialis tendon bends through the cuboid bone; 7) bone representing the unconnected point of the tubercle of the scaphoid; 8) an independent bony point of the posterior process of the talus; 9) an independent bony point of the medial malleolus.
