Bones of the Lower Limb

Bones of the Lower Limb

• The Lower Limb starts from the Sacroiliac Joint

Lower Limb Regions

• Gluteal Region: Posterior Part of the Pelvis and extends between the Iliac Crest and the lower border of the Gluteus Maximus Muscle
• Femoral Region (thigh): the region between the Hip and Knee Joints
• Leg (cruris): the region between the Knee and Ankle Joints
• Foot (Pedis): region distal to the Ankle Joint

Bones of the Gluteal Region

• Hip Bones (Coxae) are the bones of the gluteal region: Coxa is formed by the union of 3 bones
  • Iliac Bone
  • Ischial Bone
  • Pubic Bone
• The depression on the lateral aspect of the Hip Bone is called the Acetabulum

Coxa Articulation

• Each Coxa posteriorly articulates with the Sacrum to form the Sacroiliac Joints
• Coxae on both sides anteriorly articulate and form the Pubic Symphysis

Bony Pelvis

• Bony Pelvis is formed of 4 bones: 2 Hip Bones, Sacrum, and Coccyx
• Hip Bones (Coxa) is formed by the fusion of the Ilium, Ischium, and Pubis, which unites at the Acetabulum
• Hip Bones join with the Sacrum posteriorly at the Sacroiliac Joint, and with each other anteriorly at the Pubic Symphysis
• Pelvic Bones are connected to each other through firm Ligaments

Ilium Details

• Ala of the Ilium
• Anterior Superior Iliac Spine (ASIS)
• Anterior Inferior Iliac Spine
• Posterior Superior Iliac Spine
• Posterior Inferior Iliac Spine
• Iliac Crest
• Arcuate Line

Ischium Details

• Body
• Ramus unites with rami of pubis to form the obturator foramen
• Ischial tuberosity
• Ischial Spine
  • Lesser Sciatic Notch is between the Ischial Spine and Ischial Tuberosity
  • Greater Sciatic Notch is superior to the Ischial Spine

Pubis Details

• Body
• Superior Ramus
• Inferior Ramus
• Pubic Tubercle
• Pubic Crest is the superior rough surface of the body
• Pecten Pubis is the ridge extending laterally from the pubic tubercle
• Obturator Foramen is formed between the rami of the Pubis and Ramus of Ischium

Bony Pelvis Division

• The Bony Pelvis is divided into 2 parts by a line passing through the Terminal Line (Pectineal Line, Arcuate Line, and Sacral Promontory)
• Terminal Line determines the border of the Pelvic Inlet (line of passage from greater Pelvis to Lesser Pelvis)

False vs True Pelvis

• Greater (False) Pelvis
  • Lies Superior to the Pelvic Inlet
  • Anteriorly bounded by the Abdominal Wall
  • Some of the abdominal Viscerais situated here
• Lesser (True) Pelvis, Lies inferior to the Pelvic Inlet
  • Lies between the Pelvic Inlet and Pelvic outlet
  • Inferiorly bounded by the Pelvic Diaphragm
  • Pelvic Viscera such as the Urinary Bladder, Uterus, Ovaries, and Part of the Rectum are situated here

Pelvic Inlet

• Bordered by the Terminal Line
• The rim of the Pelvic Inlet is called the Pelvic Brim

Pelvic Outlet

• Bordered by the Inferior Margin of Pubic Symphysis, the Inferior Rami of the Pubis, Ischial Tuberosities, Sacrotuberous Ligaments, and the Tip of the Coccyx

Pelvis: Anatomical Transverse Diameter

• 13cm

Pelvic: Oblique Diameter

• 12cm

Pelvic: Sacrotyloid Diameter

• 9.5cm

Pelvic Inlet Diameter: Diameter Conjugata

• Narrowest of the pelvic inlet diameters
• Called conjugata vera, or obstetric conjugate
• Extends between the promontorium and the most posterior part of the pubic symphysis
• About 11.2 cm in an adult female
• Smaller diameters may cause delivery difficulty

Pelvic Diameter: Anatomical Conjugate

• Extends between promontorium and Upper Border of pubic symphysis
• About 12.5cm in Adult Female

Pelvic Diameter: Diagonal Conjugate

• Extends between the promontorium and Lower Border of pubic symphysis
• About 13.5cm in Adult Female
• Measured by vaginal examination

Pelvic Diameter: Transverse Diameter

• The Widest Diameter of the Inlet
• Extends between the Widest Points of the Right and Left Side of the Terminal Line
• About ma 13.5 cm or more in ADult Female

Pelvic Diameter: Diameter Obliqua

• Extends from the Sacroiliac Joint of side to Iliopubic Eminence of the Opposite Side
• Diameter from Right Sacroilic Joint to Left Iliopubic Eminence is about 13cm, other side is 12.5cm in Adult Female

Anatomical Outlet

• Anteroposterior diameter - from the lower border of pubis symphysis to the tip of coccyx, measuring at 13 cm in the 2nd stage of labor.
• Transverse diameter - between two Ischial Tuberosities, measuring at 11cm

Male vs. Female Pelvis

• Male
  • Thick and Heavy
  • Deep Greater Pelvis
  • Narrow + Deep Tapering Lesser Pelvis
  • Heartshaped and Narrow Pelvic Inlet
  • Comparatively Small Pelvic Outlet
  • Narrow (<70°) pubic arch
  • Round Obturator Foramen
  • Large Acetabulum
  • Narrow (~70°); Inverted V Greater Sciatic Notch
• Female
  • Thin and Light
  • Shallow Greater Pelvis
  • Wide + Shallow Cylindrical Lesser Pelvis
  • Oval and Rounded Pelvic Inlet
  • Comparatively large Pelvic Outlet
  • Wide (>80°) pubic arch
  • Oval Obturator Foramen
  • Small Acetabulum
  • Almost 90° Greater Sciatic Notch
• The pelvis of any individual may have some features of the opposite sex
  • Types A and C is common in males
  • Types B and A is common in white females
  • Types B and C is common in black females
  • Type D is uncommon in both sexes

Pelvis: Pelvic Fractures

• Fractures commonly occur in the weakening areas of the Pelvis: Pubic Rami, Acetabulum, Region of Sacroiliac Joint, and Ala of Ilium

Pelvis: Pelvic Joints and Ligaments

• Lumbosacral Joints
• Sacrococcygeal Joint
• Sacroiliac Joints
• Pubic Symphysis

Pelvis: Lumbosacral Joint Details

• Anterior Intervertebral Joint between L5 and S1
• 2 Posterior Zygoapophysial Joints between the Articular Processes
• Supported by the Iliolumbar Ligament

Pelvis: Sacrococcygeal Joint Details

• Has an Intervertebral Disk
• Anterior and Posterior Sacrococcygeal Ligaments that provide support

Pelvis: Sacroiliac Joint Details

• Synovial Joints having little Movement ability: The Sacrum is suspended between 2 Iliac Bones
• Supported by the Interosseous and Sacroiliac Ligaments
• Superior movement of the Sacrum is further limited by 2 Ligaments
  • Sacrotuberous Ligament extends from the Posterior Inferior Iliac Spine, Sacrum, and Coccyx to the Ischial Tuberosity: It forms the Greater Sciatic Foramen together with the Sacrospinous Ligament; Priformis Muscle further divides this Foramen into Suprapriform and Infrapriform Foramens
  • Sacrospinous Ligament extends from the Anterior Surface of the Sacrum and Coccyx to the Ischial Spine: It forms the Lesser Sciatic Foramen together with the Sacrotuberous Ligament

Pelvis: Pubic Symphysis Joint Details

• Formed by the Union of the bodies of the Pubic Bones in the Median Plane
• Interpubic Disk is located between the Articulating Surfaces
• Superior and Inferior Pubic Ligaments supports the Joint

Pelvis: Relaxin

• Relaxation of the Pelvic Ligaments and Joints during pregnancy, due to the hormonal changes when Relaxin is present.
• A small increase results in Pelvic Diameters, which Facilitates the Passage of Fetus through the Pelvic Canal.

Bones of the Thigh and Leg

• Bones are the Femur, Patella, Tibia, and Fibula

Clinical Note: Fracture of the Femur

• Commonly occurs in the femoral neck
• Mostly occurs in the elderly that suffer from osteoporosis and commonly related to falls
• Avascular nacrosis of the femoral head is a common side effect , caused by the disruption of arteries supplying the femoral head
• Risk of suffering a fat embolism is relativel high when bones suffer a shaft break

Clinical Note: Fracture of the tibia and fibula

-Fractures of these bones are common

• Fracture of the tibia commonly occurs at its lower 1/3 where it gets thinner
• Fractures of the fibula most commonly occurs at 3-5 centimeters above the lateral malleolus -Fractures involving both the medial and lateral malleoli is labeled as Pott's Fracture

Osteoarthritis

• The process of joint deterioration, caused by overuse, leading to cartlidge to break down, leaving bones rubbing against another

Clinical Note: Factures of the calcaneus

-Most fractures on the calcaneus are due to falls on the foot from a height.

• Flattening and widening of the heel, and the collapse of the arch is observed as well as the (traumatic flat foot)
• Another type of fracture is the avulsion fracture of the calcaneus occuring due to the sudden pull of the calcaneal tendon
• The point where calcaneal tendon attaches detaches from the bone.

Clinical Note: Metatarsal Fractures

• Stress fractures most commonly involve the 2nd and 3rd metatarsal bones
  • Stress Fractures fatigue fractures are the general term for fractures as a result of prolonged periods of excessive exercise
  • Common effect on the bone of the lower limbs, and most commonly on footbones

Clinical Note: Joints of the Lower Limbs

• Hip Joint
  • Knee Joint
  • Proximal and Distal Tibiofibular Joints
  • Ankle Joint
  • Intertarsal Joints
  • Metatarsophalangeal Joints
  • Interphalangeal Joints

The Hip Joint

• It occurs between the Acetabulum and the head of the Femur

The Hip Joints Components

• Joint Capsule
• Iliofemoral Ligament
• Ischiofemoral Ligament
• Pubofemoral Ligament
• Orbicular Zone
• Ligament of the head of Femur (Ligamentum teres) attaches at the fovea of the head of the femur, and passes to the acetabular branch, and the posterior branch of the obturator
• Transverse the acetabular attach to the sides of the acetabulum
• This turns foramen through which vessels and nerves of the joint pass

Congenital Hip Dysplasia (Dislocation)

• Head of the femur is not secured in the acetabulum
• Limitation of the abduction as well as the shortness of the relating limgis observed in newborn

Traumatic Hip Dislocation

• Traffic accidents mostly occurs in the anterior direction, forcing the femur to turn posteriorly resulting in a posterior dislocation of its head
• Avascular necrosis of the head of the femur can develop if the ligament of the head of the femur is ruptured
• Sciatic nerve might be damage due to posterior dislocations of the femur

Knee Joint Anatomy

• Between the Femur and the Tibia
• Two Menisci between the condyles of the Femur and Tibia
  • Medial Meniscus
  • Lateral Meniscus

Knee Joint Components

• The Medial (Tibial) Collateral Ligament
  • Lateral (Fibular) Collateral Ligament
  • Anterior Cruciate Ligament
  • Posterior Cruciate Ligament
• Classified into intrisinc and extratorcapsular ligments to provide joint stability

Intrinsic Knee Joint Ligaments

• Anterior Cruciate Ligament that extends from the Anterior Intercondylar and Lateral Condyle on the Femur
• Posterior Cruciate Ligament that extends between the Posterior Intercondylar and the Medial Condyle of the Femur
• Transverse Genicular Ligament that extends between anterior parts of medial and lateral menisci
• Anterior Meniscofemoral Ligament extends between the Posterior end of Lateral Meniscus and Medial Femoral Condy

Extrinsic Knee Joint Ligaments

• Patellar Ligament extends tendon ofRectus Femoris
• It Partially covers the Patella, and it Passes Anterior to it before Attaches to it and the Tibial Tuberosity
• Medial (Tibial) Collateral Ligament
• The Lateral (Fibular) Collateral Ligament
• Medial Patellar Retinaculum is a continuation of the tendon is vastus medialis
• Lateral Patellar Retinaculum is a continuation of vastus Lateralis Tendon muscle Belly
• Oblique Popliteal Ligament extension of semimembranosus Muscular Tendons
• At one end Arcuate popliteal ligament attaches to the Fibular Head. The other end is cut into both attached Tibia, and femor

Clinical Note: Injuries to the Joint

• Sports injuries of the knee joint are relatively common
  • The most commonly damaged Ligament is the Tibial Collateral Ligament
  • This will results when forces from it lateralAspect

Knee injuries

• The Tibal Collateral Ligament has attachment to the Medial Meniscus
  • Excessive movement will lead to damage to the medial Meniscus
• Rupture of the tibial Collateral is associated with tear of the medial and also an anterior Curate Ligament
  • Excessive rotation is also a major cause, especially when the knees is flexed. May also cause tears of the medial Meniscus
• Injuries to the lateral meniscus are considered are, this is because its usually looser attached to other parts

Proximal and Distal Tibiofibular Joints

• Proximal Tibio-Fibular Joint
• Distal Tibio-Fibular Joint

The Ankle Joint (Talocrural Joint) Anatomy

• Located between the Tibia, Fibula, and Talus

Ankle Ligaments

• Joint Capsule
  • Medial Collateral Ligament referred to as the deltoid ligament is composed for for ligaments
  • The ankle joint is capable of producing plantar flexion or dorsal extension

Lateral Collateral Ligament has 3 parts:

 - The Anterior Talofibular Ligament
 - The Posterior Talofibular Ligament
 - The Calcaneofibular Ligament

Art. Subtalaris (Talocalcanea)

• This Joint can make some amount of sliding movement

Art. Talocalcaneonavicularis

• This joint must be considered as the anterior part of of subtalar joint and talonavicular joint Can make inversion and eversion movements besides some sliding

Traumatic Injuries to the Ankle Joint

- This is a Common Injury
  -Mostly occurs when the ankle sprains

• Sprains are commonly on the Inversion Type
• Usually effects the Lateral Ligament Complex such as the Posterior/Anterior/Calcaneofibular ligaments/

Note: Gout

-Gout is a metabolic disease Increase production of excretion of uric acids Crystals accumulate in the joints that lead to joint inflammation

• Signs of Inflammation can be pains welling, redness and heat around the foot
• Is most effective with the first Metatarsophalangeal Joint -The Crystal in Cartilage which are crystals with forming stones

Joint types of the Lower Limb

• Joints include; Hip Joint, Knee Joint, Proximal Joint, Distal, Talocrural Join, (Subtalar),
• The Type; Spheriod, , Hinge, plain, syndesmosis, talocalcaneonavicular

Joints of the Foot

• Intertarsal Joints
• Tarsometatarsal Joints
• Metatarsophalangeal Joints
• Interphalangeal Joints

Overview of the bones in the lower limb, which starts from the Sacroiliac Joint. It covers the Gluteal region, Femoral region, Leg, and Foot. It also describes the bones of the Gluteal Region, Coxa articulation and Bony Pelvis