Development of bones of the upper and lower limbs

Shoulder. In the region of the cervical spine at the end of the second month of intrauterine life, a primary ossification point is laid. From this point, the body and the blade of the scapula are ossified.

8 the end of the first year of the child's life, the ossification point is laid in the beak-shaped process, and at the age of 15-18 - in the acromion. The fusion of the coracoid appendage and acromion with the scapula occurs in the 15-19th year. Additional points of ossification appearing in the scapula near its medial edge in 15-19 years, merge with the main ones in 20-21 years.

Clavicle ossifies early. The point of ossification appears in it at the 6th to 7th week of development in the middle of the connective tissue rudiment (endosmal ossification). From this point the body and the acromial end of the clavicle are formed, which in the newborn are already almost completely constructed from bone tissue. At the sternal end of the clavicle, cartilage is formed, in which the nucleus of ossification appears only in the 16-18th year and fuses with the body of the bone to 20-25 years.

Brachial bone. In the proximal epiphysis, three secondary ossification points are formed: in the head - more often in the 1st year of life; in a large tubercle - on the 1-5th year and in a small tubercle - on the 1-5th year. These ossification points are growing up to 3-7 years, and they join the diaphysis in 13-25 years. In the head, the condyle of the humerus (distal epiphysis), the ossification point is laid from the neonatal period to 5 years, in the lateral epicondyle - at 4-6 years, in the medial - at 4-11 years. All parts with a bone diaphyseal are bred to the year 13-21.

Elbow bone. The point of ossification in the proximal epiphysis is laid in 7-14 years. From it arise the ulnar and coronoid processes. In the distal epiphysis the points of ossification appear in 3-14 years. The bony tissue grows and forms a head and a subulate process. With the diaphyseal, the proximal epiphysis fuses in 13-20 years, and the distal epiphysis grows in 15-25 years.

Radius. In the proximal epiphysis, the ossification point is established at 2.5-10 years, and it grows to the diaphysis at 13-21 years. Formed in the distal pituitary in 4-9 years of life, the ossification point merges with the bone diaphysis at 13-25 years.

Bones of the wrist. The ossification of the cartilages, from which the wrist bones develop, begins after birth. In the 1-2-th year of the child's life, the ossification point appears in the head and hooked bones, on the third (6 months - 7.5 years) - in the trihedral, on the 4th (6 months - 9.5 years) - in semilunar, on the 5th (2,5-

9 years) - in navicular, 6-7 (1.5-10 years) - in polygonal and trapezoidal bones and on the 8th (6,5-16,5 years) - in the pea-bones.

Bones of the pastern. The laying of the metacarpal bones occurs much earlier than the wrists. In the diaphysis of the metacarpal bone, the ossification points are laid on the 9-10th week of intrauterine life, except for the first metacarpal bone, in which the ossification point appears on the 10-11th week. Epiphyseal ossification points appear in the metacarpal bones (in their heads) in the period from 10 months to 7 years. The epiphysis (head) with diaphysis of the metacarpal bone is 15-25 years old.

Phalanges of fingers. The point of ossification in the diaphysis of the distal phalanges appears in the middle of the second month of intrauterine life, then in the proximal phalanges - at the beginning of the third month and in the middle - at the end of the third month. At the base of the phalanx, the ossification points are laid at the age of 5 months to 7 years, but grow to the body in 14-21 years. In the sesamoid bones of the first finger of the hand the points of ossification are determined on the 12-15th year.

Hip bone. The cartilaginous insertion of the pelvic bone ossifies from the three primary points of ossification and several additional ones. On the 4th month of intrauterine life, the point of ossification appears in the body of the ischium, on the 5th in the pubic body and on the 6th month in the body of the ilium. Cartilage layers between the bones in the acetabulum are preserved up to 13-16 years. At 13-15 years, secondary ossification points appear in the crest, in the head, in the cartilage near the ear surface, in the sciatic hillock and in the pubic tubercle. With the pelvic bone they fuse to 20-25 years.

Femur. In the distal epiphysis, the ossification point is laid shortly before birth or shortly after birth (up to 3 months). In the 1st year, the ossification point appears in the femoral head (from the period of the newborn to 2 years), at 1.5-9 years - in a large spit, at 6-14 years - in a small spit. The fusion of the diaphysis with the epiphyses and apophyses of the femur occurs in the period from 14 to 22 years.

Patella. Ossified from several points, appearing in 2-6 years after birth and merging into one bone to 7 years of a child's life.

Tibia. In the proximal epiphysis, the ossification point is laid shortly before birth or shortly after birth. In the distal epiphysis, the ossification point appears before 2 years of life. He fused with the diaphyseal in 14-24 years, the proximal epiphysis - at the age of 16 to 25 years.

Fibula. The point of ossification in the distal pituitary is laid before the 3rd year of the child's life, in the proximal one - in the 2-6th year. The distal epiphysis fuses with the diaphysis at 15-25 years, the proximal one at 17-25 years.

The bones of the tarsus. In a newborn in the bones of the tarsus there are already 3 points of ossification: in heel, ram and cube-shaped bones. The points of ossification appear in this order: in the calcaneus - on the 6th month of intrauterine life, in the rammed - on the 7-8th, in the cuboid - on the 9th month. The remaining cartilaginous ossified after birth. In the lateral sphenoid bone, the ossification point is formed in 9 months - 3.5 years, in the medial wedge - in 9 months - 4 years, in the intermediate wedge - in 9 months - 5 years; The scaphoid bone ossifies during the period from 3 months of intrauterine life to 5 years. The additional point of ossification in the heel of the calcaneus is laid in the 5th-12th year and fuses with the calcaneus bone at 12-22 years.

Plusset bones. The ossification points in the epiphyses occur in 1.5-7 years, the epiphyses coalesce with the diaphysis at 13-22 years.

Phalanges of fingers. Diaphyzes begin to ossify at the 3rd month of intrauterine life, the ossification points at the base of the phalanges appear in 1.5-7.5 years, the epiphyses grow to the diaphysis at 11-22 years.

Variants and anomalies in the development of limb bones

Variants and abnormalities of the skeleton of the limbs are numerous.

Shoulder. The depth of the incision of the scapula varies, sometimes its edges grow together and instead of a notch a hole is formed. In rare cases, the point of ossification in the acromion does not grow to the spine of the scapula. As a result, between the acromion and the spine, a cartilaginous layer is retained throughout life.

Collarbone. Its bends can vary. Cone-shaped tubercle and trapezoidal line on the collarbone are not always determined.

Brachial bone. Above the medial epicondyle can be an outgrowth - processus supracondylaris. Sometimes it is very long and, bending, forms a hole.

Elbow and radius bones. The ulnar process does not always coalesce with the radial bone. Radial bone may be absent (rare anomaly).

The bones of the brush. In rare cases, the extra bones of the wrist develop, in particular the central bone (os centrale). Perhaps the development of additional fingers (polydactyly). The additional finger is usually located on the side of the little finger, less often - from the side of the thumb.

Hip bone. In the center of the iliac fossa there may be an orifice. In some cases, the ileal bones are strongly elongated.

Femur. Gluteal tuberosity can be strongly pronounced, in its place a mound is formed - the third spit.

The bones of the lower leg. The shape of the tibia may not be trihedral, but flattened.

Bones of the foot. Perhaps the development of additional tarsus tarsus. Thus, the posterior process of the talus bone turns into an independent triangular bone (os trigonum); the medial sphenoid bone is divided into two separate bones, etc.

The foot, as well as the hand, can have additional fingers.

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