This document discusses avascular necrosis (AVN) of the bone, also known as osteonecrosis. It begins by explaining that AVN results from interrupted blood supply to the bone, which can lead to bone and cell death. The most common sites of AVN are the femoral head, scaphoid, and talus. Non-surgical treatments include limited weight bearing, while surgical options include core decompression, bone grafting, and osteotomies to preserve the joint. More advanced cases may require joint replacement like hip resurfacing or total hip arthroplasty. Risk factors include corticosteroid use, alcoholism, trauma, and various medical conditions.

1. Dr. Anshu Sharma
Assistant Prof.
Dept. of Orthopaedics, GMC&H.

2.  Avascular Necrosis (AVN) of the bone is a
pathological process that results from
interruption of the blood supply to the bone,
either temporary or permanently.

3.  FEMORAL HEAD
 SCAPHOID
 TALUS
 HUMERAL HEAD
 RADIAL HEAD
 HUMERAL CAPITELLUM
 LATERAL FEMORAL CONDYLE

4. Death of the bone & bone cells
from interruption of blood
supply that leads to structural
changes in the
femoral head ,consequent
collapse and secondary
Osteoarthritis
 Also known as Chandler’s
Disease/ Coronary disease
of Hip.
 Young Adults 30-50 years.
 Male : Female--- 4:1
 60% => B/L

5.  M/c site => Anterolateral aspect (Being principal
Wt. bearing portion)
 Incidence increases with Steroid usage,
Alcohol & Trauma.
 AVN only occurs in FATTY MARROW, which
contains a Sparse vascular supply. In contrast
to Hematopoietic marrow which has a rich
blood supply.

6.  Idiopathic
 Trauma
 Alcohol consumption
 Corticosteroid intake
 Cushing disease
 Hemoglobinopathies
(SCD; Polycythemia)
 Caisson disease
(Dysbaric osteonecrosis)
 Cigarette smoking
 Gout and hyperuricemia
 Collagen Vascular dis.
 SLE
 Hypercoagulable states
 Hyperlipidemia
 Organ transplantation
 Pregnancy
 Gaucher disease
 Pancreatitis
 Neoplasms
 CRF
 Hemodialysis
 HIV

7.  Phase 1: at birth
Lateral epiphyseal
Metaphyseal.
 Phase 2: infantile(4 month – 4 years)
Metaphyseal supply goes on decreasing (as the
epiphyseal ossification center becomes enlarged and
prominent)
Lateral epiphyseal artery assumes major role.
 Phase 3: intermediate (4-7 years)
Growth plate becomes completely developed and as a
“firm barrier”
Lateral epiphyseal is the only source of blood supply
 Phase 4: pre-adolescent(9-10 years)
Lateral epiphyseal along with
Artery of Ligamentum Teres(that becomes prominent
now) as ….medial epiphyseal artery

8.  Phase 5: In adolescent and adults
Lateral epiphyseal artery…&
Artery of Ligamentum Teres becomes the
major source of blood supply
 WHY PREDILECTION FOR OCCURRENCE OF AVN
 ENDARTRIOLAR SUPPLY AND LACK OF COLLATERALS
 RETROGADE BLOOD SUPPLY
 SMALL DIAMETER VESSELS AT SUB-CHONDRAL REGION
 MOST OF PART IS COVERED BY ARTICULAR CARTILAGE
VASCULAR SINUSOIDS OF MARROW DON’T HAVE ANY
ADVENTITIAL LAYER SO EASILY COMPRESSED BY
MARROW EDEMA

9.  No distinguishing Clinical Features/ High index of suspicion
 Asymptomatic Pain gradual & insidious in nature
 Range Of Motion (ROM) ; patient may walk with a limp.
 Radiographic findings may appear after a delay of several
months to years following the onset of symptoms.

10.  Focal over the groin / hip or it may radiate to the buttocks,
anteromedial thigh or knee.
 Induced mechanically by standing & walking & may be eased
by rest.
 May be very intense, throbbing, deep & often intermittent.
 Worsened by coughing & at night.
 40% of patients have night pain asso. with morning stiffness.

11.  ROM may be diminished, especially after collapse of the
femoral head.
 ROM may be limited, especially in flexion, abduction &
internal rotation.
 Gait :- Patients may walk with a limp.
 The Trendelenburg sign may be Positive.
 To be diagnosed at an early stage, high index of suspicion,
especially true with U/L involvement because of the high risk
of the dev. of AVN in the C/L Hip

12.  Intravascular
 Extraosseous:
Arterial
 Intraosseous:
Arterial
Venous
 Extravascular
 Extraosseous factor
(Capsular factors)
 Intraosseous factors

13.  Most important
 Femoral Head blood supply is an End-Organ
System with poor collateral development.
 Trauma to the hip may l/t contusion or
mechanical interruption to the Lateral
Retinacular Vessels (main blood supply of the
femoral head & neck).
 Trauma , vasculitis (Raynauds ds), vasospasm
(decompression sickness).

14.  Circulating micro-emboli that block the microcirculation
of the femoral head
 In Conditions like-
1. Fat emboli (hyperlipidemia associated with
alcoholism)
2. Steroid therapy
3. SCD
4. Nitrogen bubbles in decompression sickness

15.  Enlargement of intramedullary fat cells or fat-
loading osteocytes causes the cells to expand;
this may be the most significant factor l/t
obstruction of venous drainage.
 Reducing venous outflow & causing stasis
 Caisson disease & SCD.

16.  Steroid
 Hypertrophy of Fat
cells
 Gaucher cells &
Inflammatory cells
 Encroach on
intraosseous
capillaries
 Intramedullary
circulation
 Compartment
syndrome
 Alcohol & Steroid
 Direct toxic
metabolic effect on
osteogenic cells

17. Trauma, Infection & Arthritis
Effusions within the Hip joint

18.  Normal
 Demineralization, osteopenia & osteoporosis
 Mottling & sclerosis..cystic changes
 Crescent sign ….sub-chondral fractures…..collapse
 Flattening of the femoral head
 Joint space narrowing
 Osteophytes formation with acetabular involvement
 Secondary osteoarthritis of the hip joint

21. Focal increase in the uptake

22.  MRI is most sensitive modality in detection of AVN.
 It is also useful in differentiating AVN from non-AVN
disease of femoral head.
 MRI also effective in assessing joint effusion, marrow
conversion, marrow edema, articular cartilage congruity.
 Classic Findings:- look for focal lesion in the antero-
superior portion of femoral head that is well
demarcated but is inhomogeneous.
 T1 images => low signal intensity.
 T2 images => double line sign => classic sign of AVN,
made up of 2 concentric low and high signal bands.

24. T1 shows hypointense signals
in bilateral femoral heads
(Right>Left)
T2 shows hyperintense ring like areas

25.  1960s –3 stage staging system
 1970s – 4th stage added
 Hungerford and lennox:
– added stage 0
 Most widely used……
PAUL FICAT & ARLET

27.  STAGE 0: NORMAL X-RAY ; NORMAL BONE SCAN ; NORMAL
MRI
 STAGE 1: NORMAL X RAY ; ABNORMAL –BONE SCAN & MRI
A : <15%
B : 15-30%
C :>30%
 STAGE 2: ABNORMAL X-RAY; BONE SCAN & MRI
A : <15%
B : 15-30%
C :>30%
 STAGE 3: SUBCHONDRAL COLLAPSE PRODUCING CRESCENT
SIGN
A : <15%
B : 15-30%
C :>30%

29. Crescent sign(shown
with arrow) is the
earliest indicator of
mechanical failure from
accumulated stress
fractures of non
repaired trabeculae.

30. .

31.  TO KEEP THE JOINT FROM BREAKING
DOWN.
 Preserve rather than Replacing Femoral Head
& Cartilage.
 Early Intervention has favorable impact on
the disease prognosis irrespective of T/t
modality used.

32.  Protect the involved area from excessive stress by using some form of
limited weight bearing.
 Canes or even crutches are frequently prescribed
 Don’t alter the natural course of the disorder
 INDICATIONS:-
Alternative to surgical management
Small, Asymptomatic lesions
Low weight bearing area, such as the medial aspect of the femoral
head
Poor medical condition
Following certain types of surgical procedures, such as core
decompression, grafting, and osteotomies (used as an adjunct)
Most important role :relatively advanced stages of osteonecrosis.
 Cane or Crutches can diminish symptoms and improve function
considerably until such time as a reconstructive procedure is indicated

34.  HBO improves oxygenation, reduces oedema &
induces angioneogenesis, a reduction in intra osseous
pressure & improvement in microcirculation
 Reis et al, 24 involving 16 hips in 12 patients, all
with Steinberg Stage 1 disease, gave each patient 100
consecutive days of HBO, which involved breathing
100% oxygen via a maskat 2-2.4 atmospheres
pressure for 90 minutes
 They reported that 13 of the 16 femoral heads
subsequently appeared normal on MRI after this T/t

35.  Pulsed Electromagnetic Field stimulation, is
reported to be useful for treatment of
osteonecrosis in 4 reports.
 Mechanisms Of Action:-
-Local control of inflammation
-Enhances repair activity & healing process by
stimulating neovascularisation & new bone
formation.

36.  There are only 2 papers in Pubmed.
 The only study is by Wang et al who compared
the results of such therapy in 23 patients (29
hips) with the results in a group treated with
non-vascularized fibular grafting.
 At a mean of 25 months, 79% of the shock-wave
group had improved Harris Hip Scores
compared with 29% of the group treated with
non-vascularized fibular grafting.

37.  JOINT PRESERVING PROCEDURES
A) CORE DECOMPRESSION
B ) BONE GRAFTING
C) OSTEOTOMIES
 JOINT REPLACING PROCEDURES
A) HIP RESURFACING PROCEDURE
B ) HIP REPLACEMENT
 OTHERS
A) POROUS TANTALUM ROD
B) ENDOPROSTHESIS
C) RESECTION ARTHROPLASTY
D) ARTHRODESIS

38.  A) AS ISOLATED PROCEDURE
 B) WITH ADJUVENTS
: PEMF
: BMP
: DBM
 C) WITH BONE GRAFTING( Originally by PHEMISTER)
: CANCELLOUS( BY FICAT)
: CORTICAL( cortical strut/ vascularised fibula)
:MPBG
:OSTEOCHONDRAL

39.  Core decompression is effective for symptomatic relief in
nearly all stages in all patients who present with a painful hip
secondary to ON d/t decrease of intramedullary pressure
done by it.
 Transient symptomatic relief in an advanced stage & in
already collapsing or when collapse is impending.
 It is Most Effective in Stage I & II lesions that are size A (15%
of head affected) & B (15%–30% of head affected).
 The larger the lesion, the less likely the patient is to have a
successful outcome.

40.  BIOLOGICAL CHANGES:
1. Decreases intra-ossous pressure
2. Revascularization through channel l
3. Prevention of additional ischaemic events
 MECHANICAL CHANGES:
1. Removal of the necrotic bone & thus
removing obstruction to revascularisation

41.  Ficat & Arlet proposed creating an 8 to 10 mm diameter
core track & this became a “standard” .
 Recently some authors have suggested that the same
effect of standard core can be achieved by producing
Multiple Smaller Core Tracks of 3-mm dia range. This
can be done percutaneously & theoretically # risk &
shortens the operative time & morbidity.
 Steinberg et al proposed making Smaller Angled Core
Tracks into the Necrotic Segment from the Central Core
Canal.

42.  The lateral cortical window produces a stress
riser in the proximal femur So Protect the patient
from unprotected weightbearing for the first 6
weeks.
 Reported incidence of # with core decompression
is <1% & has almost always been associated with
either a fall or failure to use protective devices
(crutches or a walker) in the first 6 week.

43.  Bone grafting procedures are a group of joint
preserving techniques that involve the removal
of the diseased femoral head segment, f/b its
replacement with 1 or more of a variety of bone
graft options.
 Most valuable in treating patients with Stage I
& II disease.

44.  1.Grafting Through Lateral Core Track
 2.Grafting Through Femoral Neck Window
 3.Grafting Through Articular Surface Window

45. PEARLS:
-Simple technique
-Minimal Invasiveness
-Avoidance of surgical
dislocation of the hip.
PITFALLS:
-Inability to directly visualize
the joint surfaces
-Inexact nature of removing
diseased bone & replacing it
with bone graft under
fluoroscopic guidance
-Risk of postoperative #

46. -Watson-Jones or Smith-Peterson approach is used
-A window is created to expose the anterio femoral
neck, at the level of the junction of the femoral
head & neck
-When Combined with a Bone Grafting procedure,
refered as the “light bulb” procedure.
-Advantage is the improved access to the necrotic
femoral head segment & the avoidance of direct
iatrogenic cartilage damage.
-Disadvantage is the creation of a cortical defect in
the femoral neck, which raises the risk of fracture

47.  With this method, the hip is surgically dislocated using a technique aimed at
preserving the blood supply to the femoral head & neck.
 Once exposed, a “trapdoor” window is made in the femoral head cartilage to
access the diseased subchondral bone.
 When combined with a bone grafting procedure, refered as the “Trapdoor”
Procedure.
 Advantage : Exposure allows a direct evaluation of the cartilage surface &
underlying diseased femoral head segment & allows for precise bone graft
placement.
 Disadvantage : Demanding technique,
Iatrogenic cartilage damage & osteonecrosis
Surgical dislocation

50.  Nonvascularized cortical
bone grafts are typically
prepared as several
struts that provide
structural support under
the articular surface
within the evacuated
segment
 This construct is often
augmented with
cancellous bone graft in
an effort to improve its
osteoconductive and/or
osteoinductive
properties

51. 1.Local pedicled grafts, which do not
require microvascular
reanastomosis.
Eg:Muscle Pedicle Bone Grafts
Vascularized Pedicle Bone Grafts
2. Free vascularized grafts, which
require a microvascular
reanastomosis.
Eg: Free Vascularized Fibula Graft

52.  The main rationale proposed for the efficacy of osteotomies is the biomechanical
effect of moving the collapsed/necrotic segment of the femoral head from the
principal weight-bearing area of the hip to an area that bears less/no direct
weight and to allow weight-bearing contact to now happen in an area of
relatively normal bone and cartilage.
Categories:-
 VALGUS or VARUS osteotomies usually combined with FLEXION or
EXTENSION.
 Trans-trochanteric rotational osteotomies– ANTERIOR or
POSTERIOR.

53.  When the necrotic segment
is located in the
anterosuperior part of the
femoral head with less than
20% posterior involvement.
 Optimal patient population
would be those that are less
than 45 years of age and
are not on steroids or
chemotherapy.

54. 1. CURVED:
(Merle D’ Aubigne
type)
2. MEDIAL
DISPLACEMENT:
( Mc Murray type)
3. ANGULATION
( Pauwel’s ‘1’ type)

55. Transposition of the necrotic focus to the ant. &
inf. part of the femoral head away from the
weight-bearing area as a result of the ant.
rotation of the head.
-PREVENTS PROGRESSIVE COLLAPSE OF
ARTICULAR SURFACE
-TO IMPROVE CONGRUITY OF JOINT
REPOSITION THE NECROTIC ANT,SUP
PART OF HEAD TO ANON- WT BEARING
AREA
-HEAD AND NECK SEGMENT ROTATED
ANT.LY AROUND ITS LONG AXIS
WT BEARING IS TRANSMITTED TO THE
POST ARTICULAR SURFACE.

57. Resurfacing Arthroplasty
Unipolar and Bipolar Arthroplasty
Total hip replacement

58.  Femoral & Acetabular
Surface Replacement &
Hemi-Surface Replacement
for Osteonecrosis of the Hip.
 > 30% femoral head
involvement
 Little Bone sacrifice

59.  For advanced osteonecrosis
of the hip.
 Excellent pain relief &
functional improvements.

60.  A novel approach in T/t
of stage I & II Precollapse
osteonecrosis.
 This rod functions
analogously to a Cortical
Strut Graft allowing
structural &
osteoconductive
properties.

61.  Debriding the necrotic zone then elevating &
supporting the collapsed segment by the injection of
cement.
 Wood and coworkers reported on very preliminary
results 21 of 20 cases.
 All patients realized immediate pain relief with
improved hip scores, with 3 patients undergoing early
conversion to total hip arthroplasty.
 Relatively invasive but may have the advantage of
maintaining femoral head congruity.
 Long-term results with perhaps a randomized
controlled series will be necessary if this is a viable
alternative to reconstructive surgery.

62.  Mostly a salvage procedure in contemporary
orthopedics.
 In the patient with significant pain & disability &
in whom nonsurgical T/t has failed with
contraindication to prosthetic replacement.
 Clinical success can be achieved as it may relieve
hip pain.
 The recommended position is 0° to 5° of adduction,
25° to 30° of flexion & 0° to 15° of external rotation.

63.  T/t of last resort
 Provides pain free mobile but unstable hip.
 Complete resection of the head & neck of the femur
 Can achieve a good range of pain-free motion & will be
able to function reasonably well for most activities of daily
living.
 The use of a shoe lift is generally necessary as a result of
the shortening of the extremity, which averages
approximately 1.5 inches.
 There will be a noticeable abductor lurch & patients will
require some form of assistive device for ambulation.
 Indication:- patient with severe pain and disability who is
not a suitable candidate for reconstruction.

64. .