Orthopaedic conditions of hip

Question 1

Describe the bony anatomy of the pelvis

Answer 1

Each hemi-pelvis = fusion of 3 bones (Ischium, Ileum and Pubis). Acetabulum = socket.

Question 2

Describe the bony anatomy of the femur

Answer 2

Long Bone. Head – articulates with acetabulum. Neck – blood supply. Greater trochanter – attachment of abductors and rotators. Lesser trochanter – attachment for Psoas.

Question 3

Describe the anatomy of the acetabulum

Answer 3

Acetabulum – part of the pelvis, cup-shaped socket. Labrum – fibrocartilaginous lining of acetabulum, deepens socket + adds stability.

Question 4

Describe the blood supply of the hip

Answer 4

Profunda femoris – branches medial and lateral circumflex arteries. MFCA (major contributor to femoral head): 2 branches – ascend to head, transverse to form cruciate anastomosis. LFCA – 3 braches – ascending branch to joint capsule, transverse branch to cruciate anastomosis, descending branch.

Question 5

What is the clinical significance of fractured neck of femur to blood supply?

Answer 5

NoF – primary blood supply enters via capsule. Fracture Neck of femur: Intracapsular fracture – blood supply disrupted; extracapsular fracture – blood supply maintained.

Question 6

What are bursae?

Answer 6

Fluid filled sacs that reduce friction between tissues to allow smooth gliding.

Question 7

Define osteoarthritis

Answer 7

Degenerative change of synovial joints: progressive loss of articular cartilage, secondary bony changes. Characterised by worsening pain and stiffness to affected joint – limiting everyday life.

Question 8

What is trochanteric bursitis

Answer 8

Trochanteric bursa – fluid filled sac that sandwiched between hip abductors and ITB. Inflammation of this bursa causing swelling. F>M.

Question 9

What are the causes of trochanteric bursitis?

Answer 9

Trauma. Over-use – athletes, often runners, repetitive movements. Abnormal movements – Distant problem e.g. scoliosis or Local problem – muscle wasting following surgery, total hip replacement, OA.

Question 10

Describe the clinical presentation of trochanteric bursitis

Answer 10

Presents: Lateral hip pain, point tenderness.
Examination: LOOK – scars from previous surgery, muscle wasting (gluteals); FEEL – Tenderness at Greater Tuberosity; MOVE – worst pain in active abduction.

Question 11

What investigations are used for trochanteric bursitis?

Answer 11

X-ray: may be normal, OA, THR, spine abnormalities
MRI – shows soft tissues and fluid
USS – can be therapeutic as well as diagnostic, guided injection.

Question 12

What are the treatment options for trochanteric bursitis?

Answer 12

NSAIDs. Relative rest / activity modification.
Physiotherapy – correct posture, abnormal movements, stretching, strengthen muscles around joint.
Injection – CCS.
Surgery – bursectomy (rarely required)

Question 13

What is avascular necrosis?

Answer 13

Death of bone due to loss of blood supply. M> F, avg. 35-50, 80% bilateral.

Question 14

What are risk factors for avascular necrosis?

Answer 14

Trauma – irradiation, fracture (intracapsular #, femoral head blood supply), dislocation, iatrogenic.
Systemic – idiopathic, hypercoagulable states, steroids, haematological (sickle cell disease, lymphoma, leukaemia), Caisson’s disease, alcoholism.

Question 15

Describe the pathology of idiopathic avascular necrosis

Answer 15

Intravascular coagulation is the final common pathway. Pathoanatomic cascade: coagulation of intraosseous microcirculation –> venous thrombosis –> retrograde arterial occlusion –> intraosseous hypertension –> reduced blood flow to head –> cell death –> chondral fracture and collapse.

Question 16

What is the clinical presentation for avascular necrosis?

Answer 16

Symptoms: insidious onset of groin pain, Pain with stairs, walking uphill and impact activities, limp.
Examination: largely normal, may replicate early arthritis – reduced ROM (partial internal rotation), stiff joint.

Question 17

What investigations can you use for avascular necrosis?

Answer 17

X-ray, MRI, CT, Radionuclide bone scan.

Question 18

What are the non-operative treatment options for avascular necrosis?

Answer 18

Reduce weight-bearing. NSAIDs. Bisphosphonates – early AVN, controversial. Anticoagulants. Physiotherapy – maintain ROM, keep the ball round!

Question 19

What are the surgical treatment options for avascular necrosis?

Answer 19

Restore blood supply – core decompression +/- vascularised graft. Move the lesion away from the weight bearing area – rotational osteotomy. Total hip Replacement.

Question 20

What is Femoroacetabular Impingement (FAI)?

Answer 20

Common cause of hip pathology in younger patient, secondary OA. Anatomical phenomenon: Broadly divided into 2 categories – cam lesion (extra bone on head of femur resulting in bump), pincer (abnormally shaped socket that covers femoral head excessively); results in impingement of femoral neck against the anterior edge of acetabulum.

Question 21

What are associated injuries to FAI?

Answer 21

Labral tear and degeneration. Cartilage damage and flap tear. Secondary hip OA.

Question 22

What is the clinical presentation of FAI?

Answer 22

Groin pain – worse with flexion. Mechanical symptoms – block to movements, pain with certain manoeuvres such as getting out a chair, squatting and lunging.
Examination - reduced flexion and internal rotation. Positive FADIR test – Flexion, Adduction, Internal Rotation.

Question 23

How would you investigate FAI?

Answer 23

X-ray – identify the bony pathology.

MRI – useful for assessing assoc. conditions – labral tears, articular cartilage damage.

Question 24

What is the non-operative treatment for FAI?

Answer 24

Activity modification. NSAIDs. Physiotherapy – correct posture, strengthen muscles around joint.

Question 25

What is the operative treatment for FAI?

Answer 25

Arthroscopy – shave down the defect, deal with labral tears, resect artic cartilage flaps.
Open surgery – resection, periacetabular osteotomy, hip arthroplasty – resurfacing and replacement.

Question 26

What is labral tear and its causes?

Answer 26

Involves labrum (ring of cartilage) that surround outside rim of hip joint, most common anterosuperior tear. All age groups, common in active females. Causes – FAI, trauma, OA, dysplasia, collagen diseases – Ehlers-Danlos.

Question 27

How does a labral tear present?

Answer 27

Groin or hip pain, snapping sensation, jamming or locking. Examination – can be normal, positive FABER test – Flexion, Abduction, External Rotation (Anterior tears).

Question 28

How would you investigate a labral tear?

Answer 28

Ensure adequate imaging so identify any root causes of pathology. X-ray – OA, dysplasia. MRI Arthrogram – 92% sensitive. Diagnostic injection – local anaesthetic.

Question 29

What are the treatment options for a labral tear?

Answer 29

Non-operative – activity modification, NSAIDs, Physiotherapy, steroid injection.
Operative: arthroscopy – repair, resection.