Case 25- anatomy

Question 1

The location of the lesser trochanter

Answer 1

Medial aspect of the proximal femur

Question 2

The location of the intertrochanteric crest

Answer 2

Running between the greater and lesser trochanters on the posterior aspect of the proximal thigh

Question 3

The location of the gluteal tuberosity

Answer 3

Inferior to the intertrochanteric crest on the posterior aspect of the proximal femur, attachment of the gluteus maximus

Question 4

The location of the quadrate tuberosity

Answer 4

Approximately half-way along the intertrochanteric crest on the posterior aspect of the proximal femur. Attachment of the quadratus femoris

Question 5

The location of the Pectineal line

Answer 5

Running inferiorly from the lesser trochanter on the postero-medoal aspect of the proximal femur, attachment of the pectineis

Question 6

The location of the intertrochanteric line

Answer 6

Running between the greater and lesser trochanters on the anterior aspect of the proximal femur

Question 7

Intracapsular ligaments of the hip

Answer 7

• Transverse acetabular ligament: Completes the labrum and forms acetabular foramen.
• Ligamentum teres: (ligament of the head of femur): Connects the fovea to the acetabulum. Provides passage for acetabular branch of obturator artery (artery of ligament of head of femur) into the head of the femur.
• The intrinsic hip ligaments restrict extension

Question 8

Intrinsic (Extracapsular) ligaments of the hip

Answer 8

• Ischiofemoral ligament: Supports the posterior aspect of the hip joint. Limits extension and medial rotation. Holds the femoral head in the acetabulum
• Iliofemoral ligament: Supports anterior/superior aspect of hip joint. Limits extension and lateral rotation of the hip. Main role is to prevent extension
• Pubofemoral ligament: Supports anterior/inferior aspect of the hip joint. Limits extension and lateral rotation of the hip. Limits medial rotation

Question 9

What type of joint is the hip joint

Answer 9

The hip joint is a multi-axial ball and socket synovial joint. The shape of the acetabulum and support of ligaments and muscles around the joint increase the stability of the joint but reduce the range of movement (when compared to the shoulder joint).

Question 10

Head of femur

Answer 10

Covered in articular hyaline cartilage except the fovea. Only 50% of the head articulates with the acetabulum at any one time

Question 11

Acetabulum

Answer 11

1) Meaning ‘vinegar cup’. The articular (lunate) surface is covered in hyaline cartilage.
2) Non-articulating acetabular fossa contains a fat pad for joint cushioning.
3) Deepened by a fibrocartilaginous acetabular labrum in an incomplete ring.
4) Remaining inferior portion of the ring is completed by the transverse acetabular ligament.
5) Vessels and nerves to the hip joint enter through the acetabular foramen beneath the transverse acetabular ligament.

Question 12

Ligament of the Head of the Femus

Answer 12

Meaning ‘vinegar cup’. The articular (lunate) surface is covered in hyaline cartilage. Non-articulating acetabular fossa contains a fat pad for joint cushioning. Deepened by a fibrocartilaginous acetabular labrum in incomplete ring. Remaining inferior portion of the ring is completed by the transverse acetabular ligament. Vessels and nerves to the hip joint enter through the acetabular foramen beneath the transverse acetabular ligament.

Question 13

Joint capsule- hip bone

Answer 13

Strong fibrocartilaginous capsule. Non-articular surfaces are lined with synovial membrane. IIiopsoas bursa protects the tendon of iliopsoas from the anterior aspect of the hip joint. Ring of circular fibres of capsule forms orbicular zone. Intrinsic ligaments provide joint stability.

Question 14

Angles of movement- Hip

Answer 14

• Lateral rotation (60 degrees) Limited by iliofemoral and pubofemoral ligaments, and the medial rotators
• Flexion (120 degrees). Limited by soft tissue and tension in hip extensors
• Extension (25 degrees). Limited by the extracapsular ligaments
• Abduction (45 degrees). Limited by the adductor muscles, and pubofemoral and iliofemoral ligament
• Adduction (20-30 degrees). Limited by the abductors, and also soft tissue apposition (the other lower limb).
• Medial rotation (30 degrees) Limited by the ischiofemoral ligament, and lateral rotators

Question 15

External (lateral rotation) of the hip joint

Answer 15

• Piriformis (sacrum to greater trochanter, nerve to piriformis)
• Superior gemellus (ischium to greater trochanter, nerve to obturator internus)
• Obturator internus (obturator membrane to greater trochanter, nerve to obturator internus)
• Gemellus inferior (ischium to greater trochanter, nerve to quadratus femoris)
• Quadratus femoris (ischium to quadrate tubercle, nerve to quadratus femoris)
• Obturator externus (obturator membrane to greater trochanter, obturator nerve)

Question 16

Internal (medial rotation)

Answer 16

• Gluteus medius (ilium to greater trochanter, superior gluteal nerve)
• Gluteus minimus (ilium to greater trochanter, superior gluteal nerve)
• Tensor fasciae latae (ilium to iliotibial tract, superior gluteal nerve)

Question 17

Hip abductors

Answer 17

• Gluteus medius (ilium to greater trochanter, superior gluteal nerve)
• Gluteus minimus (ilium to greater trochanter, superior gluteal nerve)

Question 18

Abductor weakness

Answer 18

Trendelenburg’s sign can indicate abductor muscle weakness or superior gluteal nerve damage. This sign is characterised by a pelvis drop on the non weight bearing side during locomotion.

Question 19

Hip adductors

Answer 19

• Adductor magnus (pubis and ischium to linea aspera and adductor tubercle, obturator nerve)
• Adductor longus (pubis to linea aspera, obturator nerve)
• Adductor brevis (pubis to linea aspera, obturator nerve)
• Gracilis (pubis to pes anserinus of tibia, obturator nerve)
• Pectineus (pectineal line of pubis to pectineal line of femur, femoral and obturator nerve)
• Obturator externus (obturator membrane to greater trochanter, obturator nerve)

Question 20

Hip flexors

Answer 20

• Iliopsoas (ilium and vertebral column to lesser trochanter, femoral nerve)
• Sartorius (anterior superior iliac spine to pes anserinus of the tibia, femoral nerve)
• Rectus femoris (anterior inferior iliac spine to patella tendon, femoral nerve)*
• Tensor fasciae latae, pectineus, adductor longus, adductor brevis and gracilis also contribute to hip flexion.

Question 21

Hip extensors

Answer 21

• Gluteus maximus (ilium to gluteal tuberosity, inferior gluteal nerve)
• Semitendinosus (ischium to pes anserinus of tibia, tibial division of sciatic nerve)
• Semimembranosus (ischium to medial tibia, tibial division of sciatic nerve)
• Biceps femoris (long head ischium and short head linea aspera to fibula, tibial division of sciatic nerve)
• Hamstring part of adductor magnus (ischium to adductor tubercle, tibial division of sciatic nerve)

Question 22

Shenton’s line

Answer 22

An imaginary curved line from the inferomedial aspect of the femoral shaft and femoral neck and the superior border of the obturator foramen, this line should be smooth and continuous. Disruption in this line could be a fractured neck of the femus or developmental dysphasia of the hip.

Question 23

Common hip fractures

Answer 23

Hip fractures include an intertrochanteric fracture, femoral shaft (sub-trochanteric) fracture and a femoral neck fracture.

Question 24

Traumatic hip dislocation

Answer 24

Typically occurs in cases of major trauma. Most commonly its posterior dislocation (i.e. in a road traffic accident). Fractures of the acetabular rim and damage to the posterior thigh structures (including the sciatic nerve) can occur in posterior dislocation. Anterior dislocation can also occur.

Question 25

Development dysphasia of the hip

Answer 25

Congenital hip displacement can occur in neonates when the head of the femur does not articulate with the malformed, shallow acetabulum.

Question 26

Osteoporosis

Answer 26

Reduced bone density and mass Equal loss of mineral and organic matrix Increased risk of fractures

Question 27

Osteoporosis- Pathogenesis

Answer 27

1) Uncoupling of normal balance between bone formation and resorption 2) Bone resorption exceeds bone formation-too much resorption (high turnover), too little formation (low turnover) 3) Bone present is biochemically normal

Question 28

Risk factors for osteoporosis (women)

Answer 28

USA: 1:2 female > 50 years will suffer an osteoporosis-related fracture (male = 1 in 8) Why- females have a lower bone mass and oestrogen is involved Most frequent in postmenopausal women- natural loss with ageing exacerbated. Lack of oestrogen promotes bone resorption (high turnover). Most bone loss in the first ten years after the menopause or oophorectomy

Question 29

Other risk factors for osteoporosis

Answer 29

1) Genetics 2) Ethnicity- northern european and Asian 3) Smoking and alcohol 4) Immobilisation- low physical activity, astronauts 5) Drug induces= corticosteroids inhibit bone formation (low turnover) 6) Testosterone deficiency (males)- hypogonadism

Question 30

Major risk factors for osteoporosis

Answer 30

History of fracture as an adult Fragility fracture in first degree relative Low body weight (< 127 lb)

Question 31

Additional risk factors for osteoporosis

Answer 31

``` Impaired vision Oestrogen deficiency at early age (< 45) Dementia Poor health/frailty Recent falls Low calcium intake (lifelong) ```

Question 32

What conditions increase the risk of osteoporosis

Answer 32

``` COPD Cushing’s syndrome Eating disorders Hyperparathyroidism Hypophosphatasia IBS RA - autoimmune connective tissue disorders Insulin dependent diabetes Multiple sclerosis Multiple myeloma Stroke (CVA) Thyrotoxicosis Vitamin D deficiency Liver diseases ```

Question 33

Postmenopausal osteoporosis- therapy for prevention and treatment (Oral bisphosphonates)

Answer 33

1) First-line choices - alendronic acid, risedronate sodium 2) Anti-fracture efficacy 3) Reduce occurrence of vertebral, non-vertebral and hip fractures 4) Adsorbed onto hydroxyapatite 5) Induce apoptosis of osteoclasts 6) Reduces rate of bone turnover

Question 34

Intravenous bisphosphonates

Answer 34

Ibandronic acid, zoledronic acid, denosumab, raloxifene hydrochloride alternative if intolerant of oral bisphosphonates or contra-indicated.

Question 35

Postmenopausal osteoporosis- therapy for prevention and treatment (HRT)

Answer 35

Younger postmenopausal females with menopausal symptoms who are at a high risk of fractures. Risk of adverse effects- cardiovascular, cancer in older postmenopausal females and long term HRT therapy

Question 36

Postmenopausal osteoporosis- therapy for prevention and treatment (Teriparatide)

Answer 36

Treatment is limited to 24 months Reserved for postmenopausal females- severe osteoporosis High risk of vertebral fractures

Question 37

Glucocorticoid induced osteoporosis

Answer 37

Glucocorticoid therapy associated with bone loss and increased risk of fractures Bone-protection treatment should be started at the onset of therapy if risk fractures Oral bisphosphonates - First-line treatment

Question 38

Osteoporosis in men

Answer 38

Long-term androgen deprivation therapy for prostate cancer - increased fracture risk Oral bisphosphonates - First-line treatment

Question 39

Useful investigations in diagnosing bone disease

Answer 39

``` X-ray BMD ( DEXA calcaneum) Screening DEXA ( Dual Energy X–Ray Absorptiometry) FRAX Hormone levels Quantitative CT Scan Body Composition Analysis to detect bone loss MRI ```

Question 40

Dual energy x-ray absorptiometry (DEXA)

Answer 40

Diagnose of assess risk of osteoporosis Measure BMD before starting treatment that may have an adverse effect on bone density- se hormone deprivation for treatment for breast or prostate cancer

Question 41

When may they be recommended to measure BMD

Answer 41

1) Have had a broken bone after a minor fall or injury 2) Have arthritis 3) Take oral glucorticoids for three months 4) Early menopause 5) Postmenopausal women- smoke or drink excessively, family history or hip fractures, BMI <21 6) Large gaps between periods (>years)

Question 42

Osteomalacia (Rickets in children)

Answer 42

Inadequate mineralisation of new bone matrix or osteoid | Rickets is defective mineralisation at the epiphyseal growth plates

Question 43

Causes of rickets/osteomalacia- deficient intake or absorption of vitamin D

Answer 43

Inadequate sun exposure Low dietary intake Malabsorption: Coeliac disease, Crohn’s disease, Primary biliary cirrhosis, Gastrectomy

Question 44

Causes of rickets/osteomalacia- Dietary 1-alpha hydroxylation

Answer 44

Chronic kidney disease | Vit D dependent Rickets type I (Lack of 1α-Hydroxylase)

Question 45

Causes of rickets/osteomalacia- Primary renal PO4 wasting

Answer 45

Renal tubular acidosis Fanconi syndrome X-Linked hypophosphatemia

Question 46

Other causes of rickets/osteomalacis

Answer 46

Inhibitors of mineralisation- Fluoride, Aluminium. Metabolic acidosis Defective vitamin D receptors- Vit D dependent Rickets type II

Question 47

Clinical features of rickets- at birth

Answer 47

craniotabes, softened occipital bones, flattened parietal bones can be buckled

Question 48

Clinical features of rickets- Early years

Answer 48

Widened epiphyses (wrists), frontal bossing, squared appearance to the head Presence of Rickety rosary - Beading at costo-chondral joints Groove in the rib cage (Harrison’s sulcus) Pigeon chest

Question 49

Clinical features of rickets in older children

Answer 49

``` Lower limb deformities Myopathy Lumbar lordosis and bowing of the legs Hypocalcemic tetany (severe cases) ```

Question 50

Clinical features of osteomalacis

Answer 50

Usually asymptomatic- identified incidentally in routine investigation Symptomatic= Proximal Muscle weakness Widespread bone pain – tenderness, hydration of the demineralized matrix Dull pain, worse on weight bearing Insufficiency fracture= stress upon weakened bone - bone elastic resistance decreased Abnormal gait

Question 51

Laboratory tests for osteomalacia

Answer 51

``` Serum Calcium (normal in Osteoporosis) Plasma Phosphate Vitamin D status T4, TSH PTH FSH Testosterone Bone Specific Alkaline Phosphatase (Bone ALP / BALP) Type 1 Collagen propeptides Bone resorption and Bone Formation Markers ```