FEMUR

 

The femur or the thigh bone is the only bone in thigh. It is the longest, heaviest and the strongest human bone. The name of the bone is derived from the Latin word ‘femur’ meaning ‘thigh’. The proximal end of the femur fits into the socket in the pelvis called as hip joint, and the bottom of the femur connects to the tibia and patella to form the knee joint.

The femur length on an average is 26.74% of an individual height.

The proximal end has a pyramid shaped neck attaches the spherical head at the top and the cylindrical shaft at the bottom. There are two prominent bony protrusions, greater and lesser trochanter which attaches muscles that helps in the motion of both hip and knee joints. The angle between neck of the femur and the shaft is known as the inclination angle which is about 128 degrees in an average adult which decreases with the age. In general population without any severe tibiofemoral deformities, the femoral-tibial angle is almost about 175 degrees.

The head of the femur is directed medially upwards and slightly forwards. The shaft is directed obliquely downwards and medially so that the lower surfaces of the two femoral condyles lie in the same horizontal plane.

The femoral length is associated with a striding gait, strength, weight and muscular forces it is required to withstand. The femur supports all the body weight while standing or doing other activities like running, walking, jumping, etc., stability of the gait and is an essential component of the lower kinetic chain. The weight of the upper body rests on the femoral heads. The degree of the femoral obliquity varies between individuals but is greater in women than in men.

The femur is divided into three parts: Proximal, Shaft and Distal.

PROXIMAL FEMUR

The proximal femur contains head, neck, greater trochanter, lesser trochanter, Intertrochanteric line and intertrochanteric crest.

FEMORAL HEAD

It faces antero-supero-medially to articulate with the acetabulum. The head is of a spheroidal shape. Its smoothness is interrupted posteroinferior to its centre by a small, rough fovea which is an ovoid depression. The fovea is connected through the round ligament to the sides of the acetabular notch known as the ligamentum teres. The head of femur articulates with the acetabulum to form a ball and socket joint known as hip joint. The femoral head is intracapsular and is encircled distal to its middle line by the acetabular labrum. The articular margin is distinct except anteriorly, where the articular surface extends to the femoral neck.

NECK

The femoral head narrows considerably to form a cylindrical neck that connects the head with the shaft with an average angle of 127 degrees also known as angle of inclination or neck-shaft angle. The neck is almost 4-5 cm long. The angle of inclination provides movement at the hip joint, allows the limb to swing and also provides a lever for the action of the muscles at the hip joint. The angle is widest at the birth and diminishes gradually until the age of 10 years and is smaller in the females due to wider pelvis. It is strengthened by a thickening of bone called calcar femorale present along the concavity. The neck is laterally rotated with respect to the angle of anteversion which is almost 10-15° and this varies from person to person. The neck is rounded, upper surface is almost horizontal and slightly concave, while the lower surface is straighter, oblique, directed inferolaterally and backwards to the shaft near the lesser trochanter.

The neck has 2 borders and 2 surfaces. The upper border is concave and horizontal which meets the shaft at the greater trochanter. The lower border is straight and oblique which meets the shaft near the lesser trochanter. The anterior surface is flat and meets the shaft at the intertrochanteric line, which is entirely intracapsular. The posterior surface is convex from above downwards and concave from side to side and meets the shaft at the intertrochanteric crest.

GREATER TROCHANTER

The greater trochanter is large, irregular, box shaped apophysis present laterally and posteriorly and is the most lateral prominent of the femur. The highest point of the greater trochanter is higher than the neck of the femur and it reaches the midpoint of the femur. It can be palpated very easily. It has an upper border with an apex which is inturned posterior part of the posterior border. The greater trochanter also has three surfaces: Anterior, Medial and Lateral. The anterior border is rough in the lateral part. The medial surface has a rough impression above and a deep trochanteric fossa below which presents a tubercle. The lateral surface is crossed by an oblique ridge directed downwards and forwards, it is palpable when muscles are relaxed.

LESSER TROCHANTER

The lesser trochanter is a cone shaped extension of the lowest part of the femoral neck. It is smaller than the greater trochanter. It projects from the postero-medial side of the femur. The lesser trochanter is not palpable.

INTERTROCHANTERIC LINE

The intertrochanteric line is a prominent ridge at the junction of the anterior surface of the neck and shaft which descends medially from a tubercle on the upper part of the anterior aspect of the greater trochanter to a point on the lower border of the neck and anteriorly to the lesser tubercle. Distally this line is known as the pectineal line which serves as the anterior attachment of the hip joint capsule.

INTERTROCHANTERIC CREST

The intertrochanteric crest marks as a junction of the posterior surface of the neck with shaft of femur. It is a smooth rounded ridge, which starts above at the posterosuperior angle of the greater trochanter and ends at the lesser trochanter. The rounded elevation, a little above its middle is called as the quadrate tubercle (linea quadrata) which is almost 5cm in length.

SHAFT

The shaft or the body of the femur is large, thick and almost cylindrical in form. It is little broader above than in the center, widest and somewhat flattened from before backward below. It is slightly arched hence it is convex in anterior side and concave in posterior side, where it is strengthened by a prominent longitudinal ridge known as linea aspera which divides proximally and distal as the medial and lateral ridge.

In the upper 1/3^rd of the shaft, two lips of linea aspera diverge to enclose an additional posterior surface. It has 4 borders: Medial, Lateral, Spiral line and Lateral lip of the gluteal tuberosity. It also has 4 surfaces: Anterior, Medial, Lateral and Posterior. The gluteal tuberosity is a broad roughened ridge on the lateral part of the posterior surface.

In the middle 1/3^rd shaft has 3 borders: Medial, Lateral and Posterior & 3 surfaces: Anterior, Medial and Lateral. The medial and lateral borders are rounded and ill-defined, but the posterior border is in the roughened ridge as linea aspera. The medial and lateral surfaces are directed more backwards than towards the sides. Its subjacent compact bone is augmented to withstand compressive forces which are concentrated here by the anterior curvature of the shaft. Nutrient foramina, directed proximally, appear in the linea aspera, varying in number and site, one usually near its proximal end, a second usually near its distal end.

In the lower 1/3^rd of the shaft the two lips of linea aspera diverge as supracondylar lines to accommodate popliteal surface. This part of the shaft also has 4 surfaces: Anterior, Medial, Lateral and Popliteal. Anterior surface is smooth and convex for most of the part. The upper portion of this surface has a roughened area called the patellar fossa. Posterior surface also known as popliteal surface is smooth and concave throughout most of its length. The linea aspera extends upwards from the upper two-thirds of the posterior surface and ends just above the condyles. Medial surface is relatively flat and smooth. Contains the adductor tubercle, a roughened area near the upper part of this surface for attachment of the adductor muscles, which pull the thigh towards the midline. The medial condyle, a rounded bony prominence, forms the lower part of the medial surface. Lateral surface is convex and smoother than the medial surface. The lateral condyle, a rounded bony prominence, forms the lower part of the lateral surface.

DISTAL END

The distal end of the femur is cuboid in form and widely expanded as a bearing surface for the transmission of the weight to the tibia. It has 2 condyles, medial and lateral. Anteriorly, the condyles are merging and continues into the shaft. The condyles are slightly prominent and are separated by a smooth shallow articular depression called patellar surface. Posteriorly, the condyles are separated by a deep intercondylar fossa or intercondylar notch and project beyond the plane of the popliteal surface. The distal end articulates with tibia and patella which forms the knee joint. The articular surface for knee joint is a broad area like an inverted U shape and has 2 surfaces, Tibial and Patellar.

PATELLAR SURFACE

The patellar surface extends anteriorly on both the condyles, especially the lateral then medial. It is transversely concave, vertically convex and grooved for the posterior patellar surface. The anterior border is therefore oblique and runs distally and medially, separated from the tibial surfaces by two small grooves that crosses the condyles obliquely. The lateral groove runs laterally and bit forwards from the front of the intercondylar fossa and expands to form a small triangular depression which rests on the anterior edge of the lateral meniscus when the knee is fully extended. The medial groove is restricted to the medial part of the medial condyle and rests on the anterior edge of the medial meniscus in full knee extension.

TIBIAL SURFACE

The tibial surface is divided by the intercondylar fossa but is anteriorly continuous with the patellar surface and is convex in all the directions. The medial part of the tibial surface is a broad strip on the convex infero-posterior surface of the medial condyle and is gently curved with a medial convexity. The lateral part of the tibial surface is broader and passes slightly back. Both the medial and lateral surfaces have dis-similar antero-posterior curvatures.

MEDIAL CONDYLE

The medial condyle is longer and when femur is held with its body perpendicular projects to a lower level. The condyle is convex medially, has a bulging and is easily palpable. Posterosuperior to the epicondyle there is projection known as the adductor tubercle. This tubercle is an important landmark as an epiphyseal line for the lower end of the femur passes through it. The lateral surface of the condyle is the medial wall of the intercondylar fossa. A curved strip which is 1cm wide and adjoining the medial articular margin, is covered by the synovial membrane and is inside the joint capsule.

LATERAL CONDYLE

The lateral condyle is more prominent and is broader both in its antero-posterior and transverse diameters. The condyle is thicker, stronger and flat laterally and is more in the line of the shaft of femur hence it takes greater part in the transmission of the body weight to the tibia. the popliteal grove just below the epicondyle has a deeper anterior part and a shallower posterior part.

INTERCONDYLAR FOSSA OR NOTCH

The intercondylar fossa separates both the condyles distally and behind. The fossa is intracapsular but moreover extracapsular. The distal border of the patellar surface limits the fossa in front and at back intercondylar line limits the fossa separating from the popliteal surface. Its lateral wall, the medial surface of the lateral condyle, bears a flat posterosuperior impression that spreads to the floor of the fossa near the intercondylar line for the proximal attachment of the anterior cruciate ligament. The medial wall of the fossa, i.e. the lateral surface of the medial condyle, bears a similar larger area, but far more anteriorly, for the proximal attachment of the posterior cruciate ligament. Both impressions are smooth and largely devoid of vascular foramina, whereas the rest of the fossa is rough and pitted by vascular foramina. A bursal recess between the ligaments may ascend to the fossa. The capsular ligament and, laterally, the oblique popliteal ligament are attached to the intercondylar line. The infrapatellar synovial fold is attached to the anterior border of the fossa.

Attachments on the Femur

1. Fovea: Attachment for ligamentum teres.
2. Greater Trochanter:
• Piriformis at apex.
• Gluteus minimus on anterior surface.
• Obturator internus and gemelli on medial surface.
• Obturator externus in trochanteric fossa.
• Gluteus medius on lateral surface; trochanteric bursa behind it.
3. Lesser Trochanter:
• Psoas major on apex and anterior surface.
• Iliacus on base and below.
• Bursa covers posterior surface.
4. Intertrochanteric Line:
• Capsular ligament attachment.
• Iliofemoral ligament upper and lower bands.
• Vastus lateralis and medialis origin from ends of the line.
5. Quadrate Tubercle: Quadratus femoris insertion.
6. Shaft:
• Medial head of gastrocnemius on popliteal surface.
• Vastus intermedius from anterior and lateral surfaces.
• Articularis genu below vastus intermedius.
• Suprapatellar bursa related to lower anterior surface.
• Vastus lateralis from greater trochanter and linea aspera.
• Vastus medialis from intertrochanteric line and linea aspera.
• Gluteus maximus, adductors, and pectineus insertions detailed along linea aspera.
7. Lateral Condyle:
• Fibular collateral ligament attachment.
• Popliteus origin in popliteal groove.
8. Medial Condyle:
• Tibial collateral ligament attachment.
• Adductor tubercle receives adductor magnus insertion.
9. Intercondylar Notch:
• Cruciate ligaments attached to condyles.
• Capsular and oblique popliteal ligament attachments.

Nutrient Artery: From second perforating artery, enters via foramen on linea aspera.

This summary maintains the original description’s essence while being more concise for easier reference.

BLOOD SUPPLY

1. Deep Femoral Artery: Supplies blood to the shaft and distal portion of the femur.

2. Medial and Lateral Circumflex Femoral Arteries: Supplies blood to the head and neck of the bone.

3. Obturator Artery: Supplies blood to the femoral head.

4. Foveal Artery: Supplies blood to the femoral head.

 

OSSIFICATION

The femur, the long bone in your thigh, has distinct growth regions at its ends called epiphyses. These epiphyses are capped with cartilage and separated from the main shaft (diaphysis) by growth plates (physes). Understanding these regions is important for various reasons, including bone development, forensic analysis, and proper imaging techniques.

Structure and Fusion:

• Upper end: There are three epiphyses at the top of the femur:
• The head (capital epiphysis) forms the ball-shaped joint with the hip socket.
• The greater trochanter, a large bony prominence for muscle attachment.
• The lesser trochanter, a smaller ridge on the posterior aspect.
• Lower end: A single epiphysis exists at the lower end of the femur.

These fuse with the shaft at different times: * Upper epiphyses (lesser trochanter, greater trochanter, head): Fuse around 18 years old. * Lower epiphysis: Fuses around 20 years old.

Ossification and Forensic Importance:

The presence of an ossification center (bone formation starting point) in the lower femoral epiphysis of a newborn found dead indicates the child was viable, meaning it could have survived independently outside the womb.

Growth and Development:

• The lower end of the femur is the primary growth region during childhood and adolescence.
• The lower epiphyseal line (growth plate) interestingly passes through the adductor tubercle, a bony bump for muscle attachment.
• In contrast, the upper head epiphysis is entirely cartilaginous in infants and not visible on standard X-rays. Ultrasound is preferred for early visualization.
• The growth plate of the head starts ossifying around 10 years old. Initially, it has a horizontal orientation, incorporating the inferomedial part of the articular surface (joint surface) into the neck region.
• Over time, the medial part of the epiphysis grows down, covering this previously neck-related articular surface. This process transforms the head into a hollow cup shape sitting atop the femoral neck.
• Notably, the epiphyseal line of the head generally follows the articular margin, except for a superior non-articular area allowing blood vessel passage into the head.

Fusion Timeline:

• Lesser trochanter: Fuses shortly after puberty.
• Greater trochanter: Fuses after the lesser trochanter.
• Capital epiphysis (head): Fuses around 14 years in females and 17 years in males.
• Distal epiphysis (lower end): Fuses around 16 years in females and 18 years in males.
• Distal epiphyseal plate: Notably, this growth plate runs through the adductor tubercle.

Ossification Process:

The femur has one primary ossification center in the shaft that appears between the 5th and 7th week of fetal development. Secondary ossification centers then emerge at different times:

• Distal end: 9th month of fetal development
• Head: 6th month after birth
• Greater trochanter: 4th year
• Lesser trochanter: 12th to 14th years

 

HAND PHALANGES

The phalanges are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones.

Each proximal phalanx consists of three parts:

• The base, which represents the expanded proximal part. It has a concave, oval-shaped articular facet that articulates with the metacarpal head to form the metacarpophalangeal (MCP) joint. The base also contains nonarticular tubercles for the attachment of various soft tissue structures.
• The body, which continues distally from the base. It tapers distally and has two surfaces: dorsal and palmar. The dorsal surface is round and smooth, appearing convex in the transverse plane. The palmar surface is flat and rough, especially on the sides where the flexor fibrous sheaths of digits attach. The surface appears flat in the transverse plane but concave in the sagittal plane.
• The head, which represents the expanded and rounded distal part. It has a pulley-shaped articular surface that articulates with the base of the middle phalanx to form the proximal interphalangeal (PIP) joint. The heads consist of smooth grooves, especially on the palmar aspects. These grooves represent the attachment points of the collateral interphalangeal ligaments of hand.

Various ligaments attach to the proximal phalanges. The most complex one is the digital fascial complex which attaches the surrounding subcutaneous tissue and neurovasculature to the bony phalanges. The collateral and palmar metacarpophalangeal ligaments attach to the bases of the proximal phalanges. They provide strength to the metacarpophalangeal joints. The collateral interphalangeal ligaments of hand attach to the heads, supporting the PIP joints. The proximal phalanges are also covered by the extensor expansion of hand on the dorsal aspect.

The proximal phalanges are very mobile at the MCP joints. They are mainly capable of flexion, extension, adduction and abduction. Circumduction and rotation are also possible, especially at the MCP joint of the thumb. These movements are enabled by the action of several muscles:

• Posterior (extensor) forearm muscles, such as extensor digitorum, extensor pollicis brevis, extensor digiti minimi and extensor indicis.
• Metacarpal muscles, such as the lumbricals, palmar interossei and dorsal interossei.
• Thenar muscles, for example flexor pollicis brevis and adductor pollicis.
• Hypothenar muscles like abductor digiti minimi and flexor digiti minimi.

These muscles carry out their functions via their direct attachments to the bases of the proximal phalanges. In addition, many extensors carry out the movements via the extensor expansion of hand which covers the phalanges

Middle phalanges

There are four middle (intermediate) phalanges in each hand because the thumb is missing one. They have a similar structure to the proximal ones, consisting of a base, body and head. The base of each middle phalanx has two concave-shaped articular facets and matches the head of the corresponding proximal phalanx. Their apposition forms the PIP joint. The heads of the middle phalanges have a pulley-like appearance. They articulate with the bases of the distal phalanges to form the distal interphalangeal (DIP) joints of hand.

The middle phalanges are reinforced by the same ligaments supporting the proximal ones, digital fascial complex, collateral interphalangeal ligaments and extensor expansion of hand. The collateral interphalangeal ligaments attach to the base and heads of the middle phalanges to reinforce the PIP and DIP joints.

The middle phalanges are less mobile compared to the proximal phalanges. They are only capable of flexion and extension at the PIP joints. Only the flexor digitorum superficialis muscle attaches directly to the sides of the middle phalanges, flexing them at the PIP joints. The remaining contributions are provided by the action of the previously mentioned muscles; the forearm extensors, metacarpal, thenar and hypothenar muscle groups. Flexion and extension are transferred to the middle phalanges from the direct action of these muscles on the proximal phalanges or via the extensor expansion of hand.

Distal phalanges

Each hand has five distal phalanges, which look shorter and slightly thicker compared to the previous two sets. Each distal phalanx has a base, body and head. The base has a double articular facet which matches the shape of the head of the middle phalanx. The distal phalanges have a smooth and round dorsal surface. In contrast, their palmar surface is wrinkled and irregular. The nonarticular heads contain an irregular, curved shaped distal tuberosity. It serves as an anchor point for the pulps of the digits.

The distal phalanges are stabilized by the digital fascial complex, collateral interphalangeal ligaments and extensor expansion of hand. The collateral interphalangeal ligaments attach to the base of the distal phalanges to reinforce the DIP joints.

The distal phalanges are capable of flexion and extension at the DIP joints. Two forearm extensors and one flexor muscle insert directly into the bases of the distal phalanges, permitting these actions. These include flexor digitorum profundus, flexor pollicis longus and extensor pollicis longus. The previously mentioned muscle groups acting on the proximal and middle phalanges also act indirectly on the distal ones via the extensor expansion of hand.

BLOOD SUPPLY

The hand phalanges are richly supplied with blood, lymphatics, and nerves, and their development involves a precise pattern of ossification. The blood supply to the phalanges comes primarily from the digital arteries, which are branches of the superficial and deep palmar arches derived from the radial and ulnar arteries. These arteries run alongside the phalanges, especially near the lateral aspects, where they give off perforating branches that penetrate the bone through nutrient foramina. Venous drainage mirrors the arterial supply, with the digital veins draining into the superficial and deep venous systems of the hand. The lymphatic drainage follows the venous pathways, with lymphatic vessels accompanying the digital veins. These vessels drain into the epitrochlear and axillary lymph nodes, playing a crucial role in immune surveillance and fluid balance in the hand.

NERVOUS SUPPLY

The nervous supply of the phalanges is derived from the median, ulnar, and radial nerves, which innervate the hand based on their anatomical distribution. The median nerve supplies the palmar side of the first three and a half fingers and their corresponding phalanges, while the ulnar nerve supplies the remaining fingers. The radial nerve provides sensation to the dorsal aspect of the phalanges, primarily for the proximal portions of the first three fingers. These nerves are responsible for transmitting sensory information, including pain, touch, and temperature, and they also play a critical role in motor function by innervating the muscles controlling finger movement.

OSSIFICATION

Ossification of the hand phalanges follows a well-defined sequence. Each phalanx typically ossifies from one primary ossification center, which appears during fetal development, generally between the 8th and 12th weeks of gestation. A secondary ossification center forms at the base of the phalanx during early childhood, usually between 2 and 4 years of age, depending on the specific phalanx and its position in the hand. The fusion of the primary and secondary ossification centers, marking skeletal maturity, occurs by 15–18 years of age. The ossification sequence begins with the proximal phalanges, followed by the middle and distal phalanges. This progression is vital for assessing growth and development in pediatric radiology and clinical evaluations.

SCAPULA

The scapula also known as the shoulder bone, shoulder blade, wing bone or blade bone, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on either side of the body being roughly a mirror image of the other. The name derives from the Classical Latin word for trowel or small shovel, which it was thought to resemble.

The scapula forms the back of the shoulder girdle. In humans, it is a flat and thin bone, roughly triangular in shape, placed on a posterolateral aspect of the thoracic cage.

GENERAL FEATURES

SURFACES: There are two surfaces costal and dorsal.

1. Costal surface or subscapular fossa is concave and directed medially and forwards. It is marked by 3 longitudinal ridges and one more thick ridge joins the lateral border which is almost rod - like. At the upper part of the fossa is a transverse depression, where the bone appears to be bent on itself along a line at right angles to and passing through the center of the glenoid cavity, forming a considerable angle, called the subscapular angle; this gives greater strength to the body of the bone by its arched form, while the summit of the arch serves to support the spine and acromion.

COSTAL SURFACE

2. Dorsal surface gives attachment to the spine of scapula which divides the surface into smaller supraspinatous fossa and a larger infraspinatous fossa. These two are connected by spinoglenoid notch which lateral to the root of the spine.

DORSAL SURFACE

BORDERS:

1. Superior border is the shortest and thinnest; it is concave and extends from the superior angle to the base of the coracoid process. It is referred to as the cranial border in animals. At its lateral part is a deep, semicircular notch, the scapular notch, formed partly by the base of the coracoid process. This notch is converted into a foramen by the superior transverse scapular ligament and serves for the passage of the suprascapular nerve; sometimes the ligament is ossified. The adjacent part of the superior border affords attachment to the omohyoideus.

Red line is Superior Border

2. Axillary border (or "lateral border") is the thickest of the three. It begins above at the lower margin of the glenoid cavity, and inclines obliquely downward and backward to the inferior angle. At the upper end it presents the infragleniod tubercle. It is referred to as the caudal border in animals.

Lateral Border

3. Medial border (also called the vertebral border or medial margin) is the thinnest and is the longest of the three borders and extends from the superior angle to the inferior angle. In animals it is referred to as the dorsal border.

Medial Border

ANGLES

1. Superior angle of the scapula or Medial angle is covered by the trapezius muscle. This angle is formed by the junction of the superior and medial borders of the scapula. The superior angle is located at the approximate level of the second thoracic vertebra. The superior angle of the scapula is thin, smooth, rounded, and inclined somewhat lateralward, and gives attachment to a few fibers of the levator scapulae muscle.

Superior angle of Scapula

2. Inferior angle of the scapula is the lowest part of the scapula and is covered by the latissimus dorsi muscle. It moves forwards round the chest when the arm is abducted. The inferior angle is formed by the union of the medial and lateral borders of the scapula. It is thick and rough, and its posterior or back surface affords attachment to the teres major and often to a few fibers of the latissimus dorsi. The anatomical plane that passes vertically through the inferior angle is named the scapular line.

Inferior angle of Scapula

3. Lateral angle of the scapula or glenoid angle also known as the head of the scapula is the thickest part of the scapula. It is broad and bears the glenoid cavity on its articular surface which is directed forward, laterally and slightly upwards, and articulates with the head of the humerus. The inferior angle is broader below than above and its vertical diameter is the longest. The surface is covered with cartilage in the fresh state; and its margins, slightly raised, give attachment to a fibrocartilaginous structure, the glenoidal labrum, which deepens the cavity. At its apex is a slight elevation, the supraglenoid tuberosity, to which the long head of the biceps brachii is attached.

Lateral angle of Scapula

PROCESSES

1. Spine or spinous process is a triangular plate of bone with 3 borders and 2 surfaces.   It divides the dorsal surface of the scapula into the supraspinatus and infraspinatus   fossae. Its posterior border is called the crest of the spine. The crest has upper and   lower lips.

2. Acromion has 2 borders, 2 surfaces and a facet.

3. Coracoid process is directed forwards and slightly laterally.

ATTACHMENTS

MUSCLES

• Subscapularis arises from the medial 2/3rds of the subscapular fossa.
• Supraspinatus arises from medial 2/3rds of supraspinous fossa including upper surface of the spine
• Infraspinatus arises from medial 2/3rds of infraspinous fossa, including lower surface of spine.
• Deltoid arises from lower border of the crest of spine and from lateral border acromion.
• Latissimus Dorsi lower fibres originate from inferior angle of scapula.
• Trapezius is inserted into the upper border of the crest of the spine and into medial border of the acromion.
• Serratus anterior is inserted along the medial border of costal surface; 1 digitation from the superior angle to the root of the spine, 2 digitations to the medial border, 5 digitations to the inferior angle.
• The long head of biceps brachii arises from supraglenoid tubercle and the short head from the lateral part of the tip of the coracoid process.
• Coracobrachialis arises from medial part of tip of the coracoids process
• Pectoralis minor is inserted into the medial border and superior surface of coracoid process.
• The long head of triceps arises from infraglenoid tubercle
• Teres minor arises from upper 2/3rds of rough strip on the dorsal surface along the lateral border.
• Teres major arises from lower 1/3rd of rough strip on the dorsal aspect of lateral border
• Levator scapulae is inserted along the dorsal aspect of the medial border, from superior angle up to root of spine
• Rhomboideus minor is inserted into medial border (dorsal aspect) opposite to root of spine
• Rhomboideus major is inserted into the medial border (dorsal aspect) between the root of spine and inferior angle
• Inferior belly of omohyoid arises from upper border near suprascapular notch.
  

LIGAMENTS

• The margin of glenoid cavity gives attachment to the capsule of shoulder joint and to the glenoid labrum
• The margin of the facet on the medial aspect of the acromion gives attachment to the capsule of the acromioclavicular joint
• The coracoacromial ligament is attached to the lateral border of the coracoids process and to the medial side of the tip of the acromion process
• The coracohumeral ligament is attached to the root of the coracoids process.
• The coracoclavicular ligament is attached to the coracoid process; the trapezoid part on the superior aspect, and the conoid part near the root. The coracoclavicular ligament is made up of 2 bands: the conoid and the trapezoid, both of which provide vertical stability. The coracoacromial ligament connects the coracoid process to the acromion.
• The suprascapular ligament bridges across the suprascapular notch and converts it into a foramen which transmits the suprascapular nerve. The suprascapular ligament lies above the ligament.
• The spinoglenoid ligament bridges the spinoglenoid notch. The suprascapular vessels and nerve pass to it.
• The acromioclavicular ligament connects the distal end of the clavicle to the acromion and provides horizontal stability
  

BURSAE

1. Scapulothoracic Bursa, between the serratus and the thorax, and
2. Subscapularis Bursa, between the subscapularis and the serratus.

OSSIFICATION

The scapula is ossified from 7 or more centers: one for the body, two for the coracoid process, two for the acromion, one for the vertebral border, and one for the inferior angle. Ossification of the body begins about the second month of fetal life, by an irregular quadrilateral plate of bone forming, immediately behind the glenoid cavity. This plate extends to form the chief part of the bone, the scapular spine growing up from its dorsal surface about the third month. Ossification starts as membranous ossification before birth. After birth, the cartilaginous components would undergo endochondral ossification. The larger part of the scapula undergoes membranous ossification. Some of the outer parts of the scapula are cartilaginous at birth and would therefore undergo endochondral ossification.

At birth, a large part of the scapula is osseous, but the glenoid cavity, the coracoid process, the acromion, the vertebral border and the inferior angle are cartilaginous. From the 15th to the 18th month after birth, ossification takes place in the middle of the coracoid process, which as a rule becomes joined with the rest of the bone about the 15th year.

Between the 14th and 20th years, the remaining parts ossify in quick succession, and usually in the following order: first, in the root of the coracoid process, in the form of a broad scale; secondly, near the base of the acromion; thirdly, in the inferior angle and contiguous part of the vertebral border; fourthly, near the outer end of the acromion; fifthly, in the vertebral border. The base of the acromion is formed by an extension from the spine; the two nuclei of the acromion unite and then join with the extension from the spine. The upper third of the glenoid cavity is ossified from a separate center (sub coracoid), which appears between the 10th and 11th years and joins between the 16th and the 18th years. Further, an epiphysial plate appears for the lower part of the glenoid cavity, and the tip of the coracoid process frequently has a separate nucleus. These various epiphyses are joined to the bone by the 25th year.

Failure of bony union between the acromion and spine sometimes occurs (see os acromiale), the junction being affected by fibrous tissue, or by an imperfect articulation; in some cases of supposed fracture of the acromion with ligamentous union, it is probable that the detached segment was never united to the rest of the bone.

Complied & Written by Dr. Palak Shah

CARTILAGE

Cartilage is a connective tissue composed of cells and fibres embedded in a firm, gel-like matrix which is rich in a mucopolysaccharide. it is more elastic than bone.

• Cartilage doesn't have blood supply nor it has lymphatics.it's nutrition diffuses through the matrix.
• It doesn't have nerves hence it is insensitive.
• Cartilage is surrounded by a fibrous membrane known as perichondrium which is similar to the periosteum in both structure and function. The articular cartilage doesn't have perichondrium so it's regeneration after injury is inadequate. 
• When cartilage dies, it forms into a bone like tissue.

TYPES OF CARTILAGE

1. HYALINE CARTILAGE: It is the most common form of cartilage. Hyalos is the Greek word for glass which describes the appearance of the tissue which is translucent, blueish-white and shiny. The cartilage is usually only 2-4mm thick. It is the embryonic form of cartilage. It is found in ribs, joints, nose. layrnx and trachea. Hyaline cartilage collagen fibres are primarily type II, extremely thin, invisible to microscope due to similar refractory properties to the matrix itself.

2. FIBROCARTILAGE: It is found where tendons and ligaments meet the bone, at the Pubic Symphysis, the Sternoclavicular joint and Annulus Fibrosus. The fibrocartilage is a very strong and pliable connective tissue. It is reinforced with collagen fibre bundles that run parallel to each other, allowing a low level stretch. Because of the abundance of collagen fibres, fibrocartilage is white in colour. It lacks a perichondrium and is composed of type II and type I collagen fibres. 

3. ELASTIC CARTILAGE: It is found in the external ear (auricle or pinna), the Eustachian tube and Epiglottis. Elastic's cartilage main role is purely structural, offering flexibility and resilience due to mixture of elastic fibres and type II collagen fibres. It is yellow in appearance without the organized structure of fibrocartilage when viewed under microscope.

COMPOSITION OF CARTILAGE

Cartilage is made up of highly specialized cells called chondrocytes and chondroblasts (chondro refers to cartilage), and other extracellular material which forms the cartilage matrix.

All connective tissue types within the human body are derived from the embryonal mesoderm. Bone, the strongest of the connective tissues, is the last to form and can remain in cartilage form well after birth. Increased cartilage to bone ratio enables a flexible and pliable new-born to exit the birth canal. A new-born has 300 bones, as opposed to the 206 of the normal adult, and all of these originate from cartilage.

From the 7th week of embryonic life, the process of ossification or osteogenesis slowly replaces cartilage with bone. This process continues into early childhood. Cartilage grows in two ways. In interstitial growth, chondrocytes proliferate and divide, producing more matrix inside existing cartilage throughout childhood and adolescence. In appositional growth, fresh layers of matrix are added to existing matrix surface by chondroblasts in the perichondrium. The perichondrium is a dense layer of connective tissue which surrounds most cartilage sites. Its outer layer contains collagen-producing fibroblasts, while the inner layer houses large numbers of differentiated fibroblasts called chondroblasts.

Chondroblasts: As long as they are free to move, chondroblasts produce the elements of the extracellular matrix (ECM). This cell type first forms a matrix of hyaluronic acid, chondroitin sulphate, collagen fibers, and water during embryonal development. Chondroblasts eventually become immobile after becoming surrounded by the matrix, and are then referred to as chondrocytes.

Chondrocytes: They are the immobile form of chondroblasts. They are surrounded by the matrix and contained within allotted spaces called lacunae. A single lacuna can contain one or more chondrocytes. Chondrocytes have varying roles according to the type of cartilage they are found in. In articular cartilage, found in the joints, chondrocytes increase joint articulation. At growth plates, chondrocytes regulate epiphyseal plate growth. While chondroblasts are ECM manufacturers, chondrocytes maintain the existing ECM and are a less active form of the same cell.

Fibroblasts: It is found in all types of connective tissue. In cartilage, these cells produce type I collagen. In certain situations, fibroblasts transform into chondrocytes.

Extracellular Matrix: There is significantly more matrix than cells in cartilage structure, as the low oxygen environment and lack of vasculature do not allow for larger numbers. Because of this, there is little metabolic activity, and little to no new growth in cartilage tissue – one of the reasons the elderly commonly suffer from degenerative joint pain. Cartilage does continue to grow slowly, however. This can be seen in the larger ears and noses of older individuals.

The ECM of cartilage contains three characteristic elements:

• Collagen

A protein-based collagen matrix gives form and strength to cartilage tissue through a mesh-like structure of fibrils. Although there are many different forms of collagen in the human body, the collagen found in cartilage is primarily type II, with an attached FACIT (short for fibril-associated collagen with interrupted triple helix) XIV collagen which determines the diameter of these fibers.

• Proteoglycans

Proteoglycans are large molecules that bind with water, providing flexibility and cushioning qualities. Proteoglycan monomers bond to hyaluronic acid by way of link proteins, as is the case with the large proteoglycan Aggrecan (chondroitin sulphate proteoglycan 

• Collagen and aggrecan in hyaline cartilage

The high numbers of negative charges such constructions provide, together with a large surface area, make it possible for proteoglycans to bind to large amounts of water. This creates high osmotic pressure, increases load-bearing, and constitutes the gel-like consistency of the ECM.

• Noncollagenous Proteins

Noncollagenous elements of the ECM are small in number and supposed to play a role in maintenance and organization of the cartilage structure on a macromolecular level.

Complied and written by Dr. Palak Shah

Human Skeleton

As described in the previous blog, how our ancestors discovered Human Body, the first and foremost thing to study was the Human Skeleton.

Skeleton includes bones and cartilages which forms the main supporting framework of the bodyand which is primarily designed for a more effective production of movements by the attached muscles.

The number of bones when a child is born are 270 which fuses when he/she becomes an adult to 206 bones. 

There are mainly two divisions of human skeleton:

1. Axial skeleton which mainly consists of vertebral column, ribcage and skull. It mainly consists of 80 bones. It mainly forms the framework and protection of a human being. 

2. Appendicular Skeleton which is mainly consisting of shoulder girdle, upper limb, pelvic girdle and lower limb. It consists of total 126 bones in total. Its main role is to provide fine and gross motor movements. 

The below picture shows clear demarcation of axial and appendicular skeleton. 

There are 5 main functions of the Skeleton:

1. Support - It provides framework to which the whole body supports and it also maintains the shape.

2. Movement - There is movement between 2 bones qhich allows the movement. It is powered by the skeletal muscles which are attached to the bones.

3. Protection - It protects our vital organs like brain, spinal cord, lungs, heart, viscera, etc.

4. Blood Cells Production - The long bones in an adult human is a site of haematopoiesis i. e. development of blood cells in the bone marrow.

5. Endocrine Regulation - The bone cells release a hormone named as Osteocalcin which mainly helps in regulating blood sugar and fat metabolism.

THE TOTAL 206 BONES OF AN ADULT SKELETON

Human Body (206)
Axial Skeleton (80)		Appendicular Skeleton (126)
Skull (28)	Torso (52)	Upper Extremity (32 x 2 = 64)	Lower Extremity (31 x 2 = 62)
Paired Bones (11 x 2 = 22) Nasal Lacrimal Inferior Nasal Concha Maxiallary Zygomatic Temporal Palatine Parietal Malleus Incus Stapes	Paired Bones (12 x 2 = 24) Rib 1 Rib 2 Rib 3 Rib 4 Rib 5 Rib 6 Rib 7 Rib 8 (False) Rib 9 (False) Rib 10 (False) Rib 11 (Floating) Rib 12 (Floating)	Scapula Clavicle Humerus Radius Ulna Scaphoid Lunate Triquetrum Pisiform Hamate Capitate Trapezoid Trapezium Metacarpal 1 Proximal Phalange 1 Distal Phalange 1 Metacarpal 2 Proximal Phalange 2 Middle Phalange 2 Distal Phalange 2 Metacarpal 3 Proximal Phalange 3 Middle Phalange 3 Distal Phalange 3 Metacarpal 4 Proximal Phalange 4 Middle Phalange 4 Distal Phalange 4 Metacarpal 5 Proximal Phalange 5 Middle Phalange 5 Distal Phalange 5	Hip (Ilium, Ischium, Pubis) Femur Patella Tibia Fibula Talus Calcaneus Navicular Medial Cuneiform Middle Cuneiform Lateral Cuneiform Cuboid Metatarsal 1 Proximal Phalange 1 Distal Phalange 1 Metatarsal 2 Proximal Phalange 2 Middle Phalange 2 Distal Phalange 2 Metatarsal 3 Proximal Phalange 3 Middle Phalange 3 Distal Phalange 3 Metatarsal 4 Proximal Phalange 4 Middle Phalange 4 Distal Phalange 4 Metatarsal 5 Proximal Phalange 5 Middle Phalange 5 Distal Phalange 5
Frontal Ethmoid Vomer Sphenoid Mandible Occipital	Hyoid Sternum Cervical Vertebrae 1 (atlas) C2 (axis) C3 C4 C5 C6 C7 Thoracic Vertebrae 1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 Lumbar Vertebrae 1 L2 L3 L4 L5 Sacrum Coccyx

Written and complied by: Dr. Palak Shah 

Evolution of Human Anatomy

The human anatomy studies to explore it began from B.C. and it still continues to explore and discover more and more...

Over the years many inventions, discoveries where seen and studied but when all these started no proper tools, machines where there but yet we humans still did!

Let us being with whom and when the exploration begin...:

1. Greek Period (B.C.)

    a. Hippocrates of Cos (circa 400 B.C.), the 'Father of Medicine', is regarded as one of the founders of anatomy. 

He had two theories in his ancient school of Greek Medicine, first was Knidian which was also known as School of Medicine which mainly focused on diagnosis. The other was Koan that mainly applied general diagnosis and passive treatment, also it focused on patient care, prognosis and not on the diagnosis. 

    b. Herophilus of Chalcedon (circa 300 B.C.), is called 'Father of Anatomy'. He was a Greek physician and was one of the first to dissect the Human Body. He distinguished cerebrum from cerebellum, nerves from tendons, arteries from veins, motor from sensory nerves, described various parts of eye, meninges, torcular Herophili, fourth ventricle with calamus scriptorius, hyoid bone, duodenum, prostrate gland, etc. He was a successful teacher and wrote a book on anatomy, A special treatise of the eyes. 

2. Roman Period (A.D.)

Galen of Pergamum (Circa 130-200 A.D.) was also known as 'The Prince of Physicians', practised medicine at Rome. He wrote on many medical subjects like anatomy, physiology, pathology, symptomalogy and treatment. He wrote on anatomy "De anatomicis-administrationibus", his teachings were followed nearly 15 centuries 

3. Fourteenth Century:

Mundinus or Mondino d'Luzzi (1276-1326) alao known as the "restorer of anatomy", was an Italian anatomistand professor at University of Bologna. He wrote a book named as Anathomia, after his death, Mondino was regarded as a "divine master" to such an extent that anything differing from the descriptions in his book was regarded as anomalous or even monstrous.

4. Fifteenth Century:

Leonardo di Vinci of Italy (1452-1519) had originated the cross sectional anatomy, also was one of the greatest geniuses the world has ever known. He made the observations that humours were not located in cerebral spaces or ventricles. He documented that the humours were not contained in the heart or the liver, and that it was the heart that defined the circulatory system. He was the first to define atherosclerosis and liver cirrhosis. He created models of the cerebral ventricles with the use of melted wax and constructed a glass aorta to observe the circulation of blood through the aortic valve by using water and grass seed to watch flow patterns. The drawing of his where created by his observation on dissection named as Treatise on painting.

5. Sixteenth Century:

Vesalius (1514-1564), also known as 'Reformer of Anatomy', was a professor at Padua. He challenged traditional anatomy by applying empirical methods of cadaveric dissection to the study of the human body by Galen thus reviving anatomy after a deadlock of about 15 centuries. His anatomical treatise De Febricia Humani Corporis, written in 7 volumes, revolutionized the anatomy which remained for 2 centuries. 

6. Seventeenth Century:
William Harvey (1578-1657) was an English physician who discovered the blood circulation. His has wrote and published it as Anatomical Exercise on the Motion of the Heart and Blood in Animals, The Works of William Harvey & The Circulation of the Blood and other writings. 

7. Eighteenth Century: 

William Hunter (1718-1783) was a London anatomist and obstetrician. His greatest work was Anatomia uteri umani gravidi. He and his brother founded Hunterian Museum. 

8. Nineteenth Century:

Dissection was mandatory for medical students. Formalin was used as a fixative in 1890s.

Roentgen discovered X-rays in 1895.

Various types of Endoscopes were devised between 1819 and 1899.

Few remarkable anatomists during this century were Ashley Cooper (British Surgeon), Cuvier (French Naturalist), Meckel (German Anatomist) and Henry Gray (wrote Gray's Anatomy).

9. Twentieth Century:

Electron Microscope was invented and also its various modificationsof itswere also devised like transmission EM & SEM, etc.

Ultrasonography & echocardiography were discovered. 

CT - Scan and MRI were devised.

Tissue culture was developed. 

Infertility was discovered, which gave hopes to families Gamete Intrafallopian Transfer (GIFT) was started. 

10. Twenty First Century:

Foetal medicine and 'in-utero' treatments are emerging.

Many vaccines are researched for various diseases including COVID 19.

by Dr. Palak Shah