AVN NECK OF FEMUR

1. Avascular Necrosis of Femoral Head
Adult Recon Team: VI/GW
Mod : GW
Supervisor:
dr. Muh. Andry Usman, Ph.D, Sp.OT(K)H&K
Tuesday, December 8th 2020

2. CASE REPORT
• A female patient of 38 years old having complaint of
difficulty & pain during walking, restricted movements of
right hip joint, pain at right hip joint since 5-6 months,
intermittent constipation. There was neither any history of
trauma nor other medical or surgical illness as well as no
any history of specific medications such as steroids etc.
Menstrual history was also normal. Patient had taken
Allopathic treatment but there was only symptomatic
relief. Surgery was advised by her physician but she was not
willing for surgery.
Sawarkar G, Case Study of Avascular Necrosis of Femoral Head, Joinsysmed 2016, vol 4(1), p 46-50.

3. CASE REPORT
• On examination, there was not any external abnormality,
sign of any wasting of muscle, swelling or any kind of injury.
Only limping of leg was found due to which freely internal
rotation of right hip joint was not possible. Patient was
unable to do cycling & swimming. No other systemic
abnormalities were seen except there was frequent
tendency of constipation in spite of taking regular diet.
Bladder habit was observed normal. X-ray pelvis (both Hip
joint) showed acute osteonecrosis in head of Right Femur
may be ruled out clinically. (Fig.1)
Sawarkar G, Case Study of Avascular Necrosis of Femoral Head, Joinsysmed 2016, vol 4(1), p 46-50.

4. CASE REPORT
Sawarkar G, Case Study of Avascular Necrosis of Femoral Head, Joinsysmed 2016, vol 4(1), p 46-50.

5. INTRODUCTION
• Avascular necrosis is a death or necrosis of bone due
to interruption of the blood supply to the femoral
head leading to ischaemia and cellular death.
• AVN hip occurs in 20.000 persons per year in US.
• Male > female
• The mean age at presentation ranges from 30 to 50
years old
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

6. ETIOLOGY
• Causes and risk factors for osteonecrosis can be divided into DIRECT and INDIRECT causes.
• Most commonly  trauma secondary to fracture and/or dislocation of the femoral head.
• Mnemonics : AS IT GRIPS 3Cs
Alcohol Abuse
Steroid
Idiopathic
Trauma
Gaucher Disease/Gout
Radiation/Rheumatoid
Infection/increased lipid/inflammatory arteritis
Pregnancy
Sickle Cell Disease
Caisson Disease/Chemotherapy
In approximately 10-20% of cases no cause can be identified
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

7. PATHOMECHANISM
Process of necrosis can be initiated in 4 different ways:
1. Severance of the local blood supply
2. Venous stasis and retrograde arterial stoppage
3. Intravascular thrombosis
4. Compression of capillaries and sinusoids by marrow
swelling
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

8. Moya Angelar J et al. Current concepts on osteonecrosis of the femoral head. WJO Journal. 2015

9. Traumatic osteonecrosis
Vascular anatomy is
particularly important
Injury of femoral head
blood supply  medial
femoral circumflex artery
20 % of femoral neck
displaced fracture 
Osteonecrosis
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

10. Non Traumatic osteonecrosis
The Mechanism are
complex
Involve 2 pathways :
1. Intravascular stasis or
thrombosis
2. Extravascular Swelling
and capillaries swelling
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

11. Intravascular Thrombosis
 80 % Cases associated with Hi-dose Steroid
drugs or alcohol abuse
- Hiperlipidemia and fatty degeneration of liver.
- Jones : Fat Embolism
 Osteonecrosis and Perthe’s disease (idiopathic)
 Thrombophillia and hypofibrinolysis
Coagulation of the intraosseus: microcirculation 
venous thrombosis  retrograde arterial occlusion 
decreased blood flow to femoral head  collapse and
chondral fracture
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

12. Extravascular marrow swelling
Hi- dose Corticosteroid and alcohol overuse  Fat
cell swelling in the marrow
Increase in the marrow fat in the femoral head
Sinusoidal compression, Venous stasis, and
retrograde ischaemia
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

13. STAGING
• In the literature, there are several classification sytem used to determine the ON stage for prognosis and assist with
treatment decision
• Two most common  Ficat and Arlet Classification or the Steinberg classification
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

14. STAGING
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

15. CLINICAL MANIFESTATION
The Early stage of bone death : Asymptomatic
• Pain : Common, Near a joint
• ‘Click in The Joint’
In the later Stage : Joint become stiff and deformed
• Local tenderness, some swelling
• Articular movement, restricted
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

16. IMAGING
Radiographs
• Recommended views : AP hip; frog lateral of
hip; AP-lateral view of contralateral hip
MRI
• highest sensitivity (99%) and specificity (99%)
• double density appearance :
– T1: dark (low intensity band)
– T2: focal brightness (marrow edema)
– Pathognomonic  “double line sign”
• order when radiographs negative and
osteonecrosis still suspected
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

17. TREATMENT
• Goal Therapy :
To preserve the biological hip joint for as long as
possible taking consideration quality of life issues :
age, mobility, occupation, and life style.
• Non surgical
• surgical
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

18. NON SURGICAL
• Indicated for precollapse AVN (Ficat Stages I-II)
• Physical Therapy  restricting weight-bearing with the use of
assistive devices such as crutches or cane.
• Medications :
a. OAINS
b. Anticoagulants
c. Cholesterol lowering statins
d. Hyperbaric oxygen
e. Bisphosphonate anti resorptive agents : Alendronate (weekly
7.5mg once by mouth for 12 weeks).
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

19. SURGICAL
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

20. Core decompression with or without bone
grafting
• indications
– for early AVN, before subchondral collapse occurs
– reversible etiology
• technique
– traditional method
• drill an 8-10 mm hole through the subchondral necrosis
– alternative method
• pass a 3.2 mm pin into the lesion two to three times for
decompression
– relieves intraosseous hypertension equals less pain
– stimulates a healing response via angiogenesis
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

21. Femoral osteotomy
• indications
– only for small lesions (<15%) in which the lesion can be
rotated away from a weight bearing surface
• technique
– typically performed through intertrochanteric region
– for medial disease
• perform varus rotational osteotomy
– for anterolateral disease
• perform valgus flexion osteotomy
• outcomes
– reported success rate of 60% to 90%, mainly in Japan
– distorts the femoral head making THA more difficult
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

22. Total hip replacement
• indications
– younger patient with crescent sign or more advanced femoral head
collapse, +/- acetabular DJD
– irreversible etiology (chronic steroid use)
– patients >40 with large lesions
• techniques
– cementless cup and stem
– care must be taken while preparing the femur as there are high rates of
femoral canal perforation
• Outcomes
– in young patients with osteonecrosis, there is a higher rate of linear wear
of the polyethylene liner and a higher rate of osteolysis than compared to
older patients who have THA for osteoarthritis
– provides good pain relief and function
A. Baig. Osteonecrosis of the femoral head: Etiology, Investigations, and Management. Article. 2018

23. Q & A

24. A 61-year-old man who reports left hip pain is seen in the emergency
department. Figure A shows a radiograph obtained at that time. Ten months
later, he reports excruciating left hip pain with ambulation. He notes that the
pain has markedly worsened over the past several weeks. Figures B and C show a
current radiograph and a coronal inversion recovery MRI scan of the pelvis. What
is the most likely diagnosis?
1. Infection of the hip
2. Fracture of the hip
3. Osteoarthritis of the hip
4. Osteonecrosis of the hip
5. Rheumatoid arthritis of the hip
1

25. A 61-year-old man who reports left hip pain is seen in the emergency
department. Figure A shows a radiograph obtained at that time. Ten months
later, he reports excruciating left hip pain with ambulation. He notes that the
pain has markedly worsened over the past several weeks. Figures B and C show a
current radiograph and a coronal inversion recovery MRI scan of the pelvis. What
is the most likely diagnosis?
1. Infection of the hip
2. Fracture of the hip
3. Osteoarthritis of the hip
4. Osteonecrosis of the hip
5. Rheumatoid arthritis of the hip
1

26. Preferred answer : 4
• The initial radiograph shows subtle flattening of the left
femoral head, suggestive of osteonecrosis but without
significant subchondral sclerosis. Figure B shows marked
collapse in the left head over the intervening 10 months,
and the MRI scan reveals collapse, significant edema in
the head, and low signal intensity in the superior
segment, all suggestive of osteonecrosis. Note that the
right hip shows MRI changes, suggesting bilateral disease
in this patient.

27. A 45-year-old with a history of sickle cell anemia reports hip pain for
the past 6 months. A radiograph of the affected hip is shown in Figure
A. Which of the following interventions has been shown to have the
best outcomes in this patient population?
1. Observation
2. Bisphosphonates
3. Hemi-arthroplasty
4. Uncemented metal on polyethylene total hip arthroplasty
5. Cemented metal on polyethylene total hip arthroplasty
2

28. A 45-year-old with a history of sickle cell anemia reports hip pain for
the past 6 months. A radiograph of the affected hip is shown in Figure
A. Which of the following interventions has been shown to have the
best outcomes in this patient population?
1. Observation
2. Bisphosphonates
3. Hemi-arthroplasty
4. Uncemented metal on polyethylene total hip arthroplasty
5. Cemented metal on polyethylene total hip arthroplasty
2

29. Preferred answer : 4
• Based on the radiographs and current literature, the best intervention is an uncemented metal on
polyethylene total hip arthroplasty.
Avascular necrosis of the hip may be idiopathic in nature or associated with alcoholism, steroid use, or as in
this case, sickle cell anemia. The Ficat staging system is used to classify avascular necrosis of the hip. Changes
in treatment are driven by development of symptoms as well as the development of subchondral bone
collapse (Ficat Stage 3). In those with with femoral head flattening (Ficat Stage 4) and acetabular
degenerative changes (Ficat Stage 5), total hip replacement has good to excellent outcomes.
Mont et al. review surgical options for avascular necrosis of the hip. Head preserving procedures are
generally reserved for those patients where the femoral head has not collapsed. Collapse and associated
arthritis warrant utilization of arthroplasty procedures.
Mont et al. conducted a systematic review to better delineate the symptomatic progression of asymptomatic
avascular necrosis of the hip. They found that patients with sickle cell disease have the highest rate of
progression to collapse. Medium sized, laterally located lesions were associated with a higher frequency of
collapse and joint preserving procedures are recommended for these.
Figure A shows radiograph of a patient with avascular necrosis; note the femoral head flattening, narrowing
of the joint space and acetabular sclerosis.

30. A 40-year-old man complains of increasing groin pain. Radiographs
show femoral head avascular necrosis with subchondral lucency but
without femoral head collapse. Which of the following medical
treatments have been shown to decrease the risk of subsequent
femoral head collapse?
1. Cyclic parathyroid hormone therapy
2. Bisphosphonate therapy
3. RANK ligand therapy
4. RANK therapy
5. Selective estrogen receptor modulator therapy
3

31. A 40-year-old man complains of increasing groin pain. Radiographs
show femoral head avascular necrosis with subchondral lucency but
without femoral head collapse. Which of the following medical
treatments have been shown to decrease the risk of subsequent
femoral head collapse?
1. Cyclic parathyroid hormone therapy
2. Bisphosphonate therapy
3. RANK ligand therapy
4. RANK therapy
5. Selective estrogen receptor modulator therapy
3

32. Preferred answer :2
• Bisphosphonate therapy is a proven method of preventing femoral head collapse in patients with
avascular necrosis and subchondral lucency.
Lai et al evaluated the effect of alendronate on patients with Steinberg stage-II or III osteonecrosis
of the femoral head. They found that alendronate prevented early collapse of the femoral head at
twenty-four months.
Agarwala et al evaluated the effect of bisphosphonate therapy on patient reported and radiographic
outcomes in femoral head avascular necrosis. They found alendronate reduces pain, improves
function and may prevent disease progression at 5 year followup.
Nishii et al evaluated the effect of alendronate on 20 hips with osteonecrosis of the femoral head
without collapse. They found a lower frequency of collapse and less patient reported pain in
patients treated with bisphosphonate therapy compared to controls at 12 month follow up.
•

33. A 41-year-old male has steroid-induced avascular necrosis of
the hip and decides to undergo metal on polyethylene total
hip arthroplasty. His 80-year-old, sedentary father had a total
hip replacement 5 years ago. With comparison to his father,
the patient should be informed of the following risk?
1. Increased risk of sciatic nerve palsy
2. Increased longevity of prothesis
3. Increased risk for polyethylene wear and osteolysis
4. Reduced range of motion
5. Lower likelihood of revision surgery
4

34. A 41-year-old male has steroid-induced avascular necrosis of
the hip and decides to undergo metal on polyethylene total
hip arthroplasty. His 80-year-old, sedentary father had a total
hip replacement 5 years ago. With comparison to his father,
the patient should be informed of the following risk?
1. Increased risk of sciatic nerve palsy
2. Increased longevity of prothesis
3. Increased risk for polyethylene wear and osteolysis
4. Reduced range of motion
5. Lower likelihood of revision surgery
4

35. Preferred answer : 3
• A younger, active patient will sustain more polyethylene wear
and osteolysis due to greater activity levels and more years of
use.
Kim et al prospectively studied 98 consecutive patients with
osteonecrosis of the femoral head with an average follow-up
was 9.3 years. Although there was no aseptic loosening of the
components, they reported a high rate of linear wear of the
polyethylene liner and a high rate of osteolysis in these high-
risk young patients (16% in cemented femoral stems, 24% in
uncemented stems).

36. THANK YOU

38. PROGNOSTIC (KERBOUL-ANGLE)
• It is the sum of the angle of the necrotic segment as
measured on both the anteroposterior and frog-lateral
radiographs.
• calculated by adding the arc of the femoral head
necrosis on a mid-sagittal and mid-coronal MR image
Low-risk group = combined necrotic angle less than
190°
• Moderate-risk group = combined necrotic
angle between 190° and 240°
• High-risk group = combined necrotic angle of more than
240°
•