non union femoral neck fractures

1. Nonunion femoral neck fractures
By
Chintamanu rajesh

2. Introduction :
• Nonunion and AVN of the femoral head are
the main complications of fracture of the
femoral neck
• Nonunion of femoral neck fractures are more
common in young than old patients
• In young, extreme force is required to produce
fracture neck femur which explains the
increased incidence of nonunion

3. • Incidence is ranging from 10-35%
• 0-5% in Non-displaced fractures
• 9-35% in Displaced fractures

4. Definition :
• # where reparative process halted ( cave 1958
)
• A particular # not united in the time it
normally unites. ( Cannot be applied uniformly
to all bones)
• FDA Panel definition (1986 )-
minimum 9 months has elapsed after injury &
no progressive sign of healing for 3 months (
cant be applied universally )

5. Anatomy of neck of femur :
• Neck connects head with shaft and is about
3.7cm long
• It makes angle with the shaft 130+/- 7 degree

6. • 2 borders & 2 surfaces
• Upper border- concave and horizontal meets
the shaft at greater trochanter
• Lower border – straight and oblique meet the
shaft at lesser trochanter

7. Vascular anatomy :
• An extracapsular arterial ring located at the
base of femoral neck
• Artery of ligamentum teres
• Epiphyseal blood supply
• Metaphyseal blood supply

8. Extracapsular arterial ring :
• Located at the base of femoral neck
• Formed by medial & lateral circumflex femoral
artery
• Superior & inferior gluteal arteries also
contribute
• Gives ascending cervical branches

9. Artery of ligamentum teres :
Derived from obturator and medial circumflex
femoral artery
Inadequate to supply femoral head with
displaced fractures

10. Ascending cervical branches :
• Can be divided into four groups – anterior,
posterior, medial , lateral.
• Of these lateral group provides most of the
blood supply to neck and head
• These arteries form subsynovial intra articular
arterial ring
• Once branches of these arteries penetrate the
femoral head they are termed as epiphyseal
arteries

13. Classification of femoral neck #:
• Garden (1961)
– Degree of displacement
– Relates to risk of vascular disruption

15. • Poor interobserver reliability
• Modified to:
– Non-displaced
• Garden I (valgus impacted)
• Garden II (non-displaced)
– Displaced
• Garden III and IV

16. • Pauwels (1935)
– Fracture orientation
– Relates to biomechanical stability
– More vertical fracture has more shear force

18. Causes of nonunion :
• Failure to reduce or maintain reduction
• Absence of cambium layer of periosteum
• Cutting of blood supply of head
• Development of shearing force at fracture site
after fracture causing vertical inclination
• Tamponade effect at fracture site due to
intracapsular nature of fracture
• Secretion of inhibitory substances at fracture site

19. Symptoms & signs :
• Usually presents with painful limp
• The pain is generally appears within few months
after fracture, where as pain from AVN generally
presents 1 to 2 years after fracture
• Shortening of affected limb
• Severe external rotation of the lower extremity
• Upward displacement of the trochanter with or
without soft tissue contracture

20. Investigations :
• Plain x-ray
• CT
• MRI
• Bone scan

21. On x-ray- Radiographic signs of nonunion
present at 3 months that indicate femoral neck
fracture nonunion are as follows :
• Change in fracture position by 10mm
• Change in screw position by 5%
• Backout of the screws by 20mm
• Perforation of the screws into hip joint

22. • CT Scan- provides the best assessment of
fracture union
It is useful to see the
 Bony appearance of stippled area
 Bony sclerosis
 Trabecular resorption
 Microfractures
 Subchondral collapse

23. • MRI- mainly useful to assess the viability of
femoral head
• Bone scan- to differentiate between AVN and
nonunion

24. Treatment :
• The factors on which the management depends
are as follows-
• Age of the patient
• Vascularity
• Remaining bone quality
• Status of the articular surface and sphericity of
the femoral head
• Alignment of the neck and shaft
• Potential limb length discrepancy

25. • Treatment modality vary both in elderly and in
young adults

26. • Replacement arthroplasty is the treatment of
choice for elderly pts in nonunion neck of
femur
• In young adults efforts are focused on
preserving the femoral head.
• It is broadly categorised into
- Head salvaging procedures
- Head sacrificing procedures

27. Head salvaging procedures :
• If femoral head is viable and adequate neck is
remaining nonunions can be treated by
- Fixation alone
- Osteotomy +/- fixation
- Muscle pedicle bonegrafting +/- fixation
- Cortical bone grafting +/- fixation
- Cancellous bone grafting +/- fixation
- Combination of osteotomy and bone grafting

28. • Fixation alone-
could be tried within 3weeks of injury which
are undisplaced or reducible

29. Osteotomy +/- fixation :
• An osteotomy is a surgical corrective procedure
used to obtain a correct biomechanical of the
extremity, so as to achieve equivocal load
transmission, performed with or without removal
of a portion of bone
• Principle of osteotomy :
- Increases the contact area
- Restores biomechanical advantage
- Moves normal articular cartilage into weight
bearing zone
- Improves coverage of head

30. • Principles of osteotomy in nonunion fracture
neck of femur-
- Line of weight bearing is shifted medially
- Shearing force at the nonunion is decreased,
because the fracture surface has become
more horizontal

31. • Types of osteotomies:
- Pauwel’s osteotomy
- Dickson’s high geometric osteotomy
- McMurray’s displacement osteotomy
- Schanz angulation osteotomy

32. Pauwel’s valgus osteotomy :
• Mechanical problem rather than biological one
• Convers shearing force into compressive force
• To transfer the center of hip rotation medially from the superior
aspect of the acetabulum to decrease the weight bearing area of
femoral head .
• Normally 15° of correction is required.
INDICATIONS:
– Trendelenburg Limb
– Adduction deformity
– Motion in adduction beyond adduction deformity
– Painful abduction
CONTRAINDICATIONS:
– Flexion of less than 60°
– Knock knees as this will increase the deformity at knee.

34. Dickson’s high geometric osteotomy :
• the line of osteotomy is changed from vertical shearing force
to a horizontal (impacting force).
• In this distal fragment is abducted to 60° after making
osteotomy just below the grater trochanter & fixed with plate.
• High rate of union
• Lengthens limb
• Improves abductor strength
• Easy to perform
• Immediate stability can be provided

36. McMurray’s dispacement osteotomy :
Pre operative planning :
Determination of the size of the bone wedge to
be removed, the position of the seating chisel
which will determine the size and angle of the
blade plate to be used.

37. • Oblique osteotomy made in the shaft of the
femur -
• Its lower border on the outer margin being
slightly below the level of lesser trochanter
• Terminates on the inner side b/w lesser
trochanter and neck
• Shaft of femur is displaced inwards by abduction
of the limb & digital pressure on the upper and
outer aspect of lower fragment – complete
inward displacement

39. • Shortens the lever arm between trochanter
and the hip leading to OA changes
• Make future arthroplasty difficult
• Not practiced and no longer popular

40. Schanz angulation osteotomy :
• To turn the shaft from the adducted to abducted
position, so that the shearing stress of weight
bearing and muscle retraction becomes an impaction
force.

41. • The femur is cut transversely at ischial tuberosity
level & the proximal fragment is adducted until it
rests against the side wall of the pelvis.
• This lengthens the distance of the gluteus medius
and provides a fulcrum so that adequate leverage of
the muscle is obtained.
• A plate is prepared and angulated sufficiently
• At operation, the bone is sectioned and the plate is
attached to proximal fragment.
• Then, the distal fragment is abducted, extended and
approximated to the distal half of the plate, which is
then attached.

43. Muscle pedicle bone grafting +/-
fixation :
• By meyer et al
• Useful in delayed presenters as well as
nonunion
• Quadratus femoris muscle insertion to the
femur is mobilised with femoral cortex and is
fixed across the fracture site posteriorly

45. Muscle pedicle bone grafting +/- bone
grafting
• By Bakshi
- Used gluteus minimus with attached bone
block fixed anteriorly
- Used in proven nonunions with absorbed
necks

46. Head sacrificing procedures :
• Unipolar arthroplasty
• Bipolar arthroplasty
• Total hip arthroplasty
• Girdlestone arthroplasty

47. • THR- is the treatment of choice in cooperative,
independent individual with normal life span
• Hemiarthroplasty- done in pt with much less
demand and leading a sedentary lifestyle

48. Decision making :
• Late presenters
- Irrespective of vascularity of head, good reduction
achieved and neck-shaft angle maintained &
If presented within 3 wks – Fix it
If presented 3wks- 3months- fixation+ BG
- MPBG
If presented after 3months with shortening and
varus of the head- Osteotomy +/- BG
If there is segmental collapse-
Replacement arthroplasty
Arthrodesis

49. Confirmed nonunion :
• Young adults ( 20-40 )
-neck is not absorbed and head is viable
fixation alone will not work
augment it with BG or osteotomy or MPBG
preserve the head as far as possible
- If neck is absorbed and head is not viable
Arthrodesis
Girdlestone arthroplasty
Bipolar- if acetabular cartilage good
THR – if articular cartilage is of poor quality

50. • Middle age group ( 40-60 ) :
If head is viable & neck is not resorbed
Fixation+BG
Osteotomy if leg is short
If there is segmental collapse
Bipolar or THR
If nosegmental collapse but evidence of AVN
osteotomy & MPBG

51. Sandhu classification :( 16-55 yrs )
• Classified nonunion of femoral neck fractures
into 3 stages taking consideration of
foolowing-
• Fracture surfaces,
• Size of proximal fragment,
• Gap between the fragments,
• Viability of the femoral head

52. • Stage 1 :
A. Fracture surfaces are still irregular ( fresh )
B. The size of proximal fragment is 2.5cm or
more
C. Gap between the fragment is 1cm or less
D. Head of the femur is viable; there is no sign
of AVN on xray,CT or MRI

53. • Stage 2 :
A. Fracture surfaces are smoothened out
B. The size of proximal fragment is 2.5cm or
more
C. The gap between fragments is >1 but <2.5cm
D. Head of the femur is viable

54. • Stage 3 :
A. Fracture surfaces are smoothened out
B. The size of the proximal fragment is <2.5cm
C. The gap between fragments is >2.5cm
D. The head of the femur show signs of AVN
If any of the feature b ,c or d is present, the
fracture is allocated to stage 3

55. • Treatment options for stage 1 :
• Closed reduction & internal fixation
• Closed reduction & internal fixation with one
screw and double fibular graft or two screws and
one fibular graft
• CR or OR and bone muscle pedicle graft based on
quadratus femoris or sartorius or tensor fascia
• Abuction osteotomy and osteosynthesis with DHS
or 135degree anle blade plate or 120 degree
double angle plate

56. • Stage 2 :
• OR, freshening of fracture surfaces and IF two
screws and one free fibular graft
• ORIF with multiple screws and muscle pedicle
bone graft
• Valgus osteotomy

57. • Stage 3 :
• Total hip arthroplasty
• Hemiarthroplasty
• Valgus osteotomy