Treatment strategies in Fractures of the neck of femur

1. Fractures of the Femoral
Neck: State of the Art
Prepared by Dr Madan Mohan
Based on J Orthop Trauma Volume 29, Number 3, March 2015

2. Anatomy
Illustration depicting a left proximal femur with
clock-face reference for description of the
position of the IRA. The IRAs in all specimens
were found within the highlighted area on the
clock face, between 6:30 and 8:00. The lesser
trochanter was typically just posterior to this
position, or less commonly at the same clock-face
position. Proposed fixation using a medial
buttress plate is illustrated

3. Biomechanics
• The mechanical stability of the osteosynthesis of a fractured bone is
composed of the stability of the implant and the stability of the bone
• The overall strength of an osteosynthesis construct at the femoral
head is less than the strength of intact bone, and even after
completion of bone healing, the healed osteosynthesis construct has
not been completely restored to the mechanical strength of intact
bone

4. • The two major forces acting on the hip joint are abductor
muscles and body weight, as defined by the joint reaction
force.
• In men, the normal joint reaction forces can be as much as
four- to sevenfold body weight, and in women, 2.5- to
fourfold body weight
• Stair climbing causes maximum hip forces of up to
sevenfold body weight.
• The use of a bedpan produces forces on the hip
equivalent to walking with the use of external supports

5. Routine Imaging Techniques
• A cross-table lateral view of the involved proximal femur.
• A frog lateral is contraindicated as it may cause displacement of an
impacted or nondisplaced femoral neck fracture.
• A physician-assisted internal rotation view of the injured hip can be
helpful to further clarify the fracture pattern and determine
treatment plans as it eliminates the normal femoral neck anteversion
• Magnetic resonance imaging is currently the imaging study of choice
in delineating nondisplaced or occult fractures that are not apparent
on plain radiographs

6. Management of Undisplaced Fractures
• Operative management of impacted and nondisplaced femoral neck
fractures (Garden I and II) usually involves in situ fixation with either
multiple cancellous lag screws or a sliding hip screw (SHS)

7. • Typically, 3 cannulated cancellous screws (6.5, 7.0, or 7.3 mm) are
placed in a parallel inverted triangle configuration (inferior,
posterosuperior, anterosuperior) with situation of the screws
adjacent to the inferior (calcar) and posterior cortices
• The inferior screw resists inferior displacement of the femoral head,
whereas the posterior screw resists posterior displacement.
• The starting point for the inferior screw should be at or above the
lesser trochanter to avoid generating a stress riser in the
subtrochanteric region

9. • The screw threads should lie sole within the femoral head to
generate a lag effect and end within 5 mm of the
subchondral bone of the femoral head
• In cases with a more significant posterior comminution, the
use of a fourth screw along the posterior cortex may improve
stability.
• In osteoporotic bone, adding a washer can aid in preventing
screw penetration through the lateral cortex and may
increase the maximal insertion torque of the lag screw,
improving screw purchase in the femoral head

10. Is the Cranial and Posterior
Screw of the “Inverted
Triangle” Configuration for
Femoral Neck Fractures Safe?
From J Orthop Trauma Volume 33, Number 7, July 2019

11. • A cranial and posterior screw that appeared radiographically
contained with the femoral neck on anteroposterior and lateral views
frequently violated the cortex in the area where the lateral epiphyseal
vessels enter the femoral head.
• Avascular necrosis of the femoral head after femoral neck fractures
may be multifactorial.
• A potential mechanism is the initial displacement causing
compression or stretching of the terminal branches of the medial
femoral circumflex artery (MFCA), or the lateral epiphyseal vessels, to
the femoral head

12. Screws that appear close to the cortex on AP and lateral
fluoroscopy or plain radiographs may perforate the cortex
because of the anatomy of the femoral neck

14. • Authors suggest that although they may appear
contained on AP and lateral radiographs, the anterior-
caudal and posterior-cranial quadrants were at
highest risk of perforation
• Vascular foramina occur more frequently on the
posterior-cranial aspect of the femoral head and neck
junction with few anteriorly.
• Potential destruction of these vessels or vascular
foramina could occur due to destruction by a extruded
wires, drill, or implants in this anatomical location.
• An extruded and retained implant could also
theoretically interfere with revascularization and
cause avascular necrosis of the femoral head

15. •Maintaining integrity of the posterior-cranial
femoral neck cortex is an important factor in
preventing fracture fixation failure and
avascular necrosis.
•If there is violation of the posterior cortex,
there is significantly lower resistance to axial
loads regardless of anatomical reduction

16. •Patients treated with an SHS have higher rates of
osteonecrosis than multiple cancellous lag screws,
possibly related to the insertion torque generated by
the large-diameter lag screw resulting in rotational
malalignment.
•An antirotation screw or wire can be used to prevent
this complication and then either removed or leave
it in place after the large diameter lag screw has
been inserted

17. Novel Treatment Options for the
Surgical Management of
Young Femoral Neck Fractures
J Orthop Trauma Volume 33, Number 1 Supplement, January 2019
From the Orthopaedic Trauma Service, Hospital for Special Surgery, New
York, NY;

18. Fixed-Angle Length-Stable Options
• Proximal femoral locking plates (PFLPs) were developed as fixed-angle
length-stable options in an effort to decrease femoral neck shortening
after fixation of femoral neck fractures (which is seen in 30% of
femoral neck fractures treated with multiple cannulated screws
(MCSs)
• Early biomechanical results of PFLPs were promising, showing
increased axial stiffness, increased resistance to shear forces,
decreased toggling, and decreased micromotion of PFLPs compared
with other traditional fixation methods; however, clinical results have
been disappointing

19. Clinical failures occur at the bone–screw
interface or fatigue failure of the plate
and are theorized to be due to the
implant stiffness that prevents
compression and micromotion necessary
for primary bone healing

20. •A new implant with multiple small-diameter sliding
cancellous screws, which lock to a side plate, has
shown promising potential for managing femoral
neck fractures
•This implant is a hybrid between cancellous lag
screws and an SHS, providing rotational stability,
controlled collapse of the femoral neck, and
prevention of screw toggling within the femoral neck

21. • Although historically a shortened and healed femoral neck
fracture was an acceptable clinical result, recent studies focusing
on femoral neck shortening and outcomes have reported a
positive association between increasing amounts of shortening
and lower quality of life measures and higher revision rates.
• Length-stable implants (fully threaded cancellous screws,
divergent cancellous screws, and proximal femoral locking plates)
and augmentation with a locked plate on the anterior–inferior
aspect of the femoral neck have been proposed as solutions for
minimizing the amount of femoral neck shortening to potentially
improve postoperative outcomes

22. Length-stable fixation using nonparallel (divergent)
cancellous lag screw fixation for a displaced femoral
neck fracture in a 30-year-old woman.

23. NOVEL TREATMENT ALTERNATIVES
• “Hybrid” fixation techniques combine the biomechanical
benefits of fixed-angle constructs with the rotational
stability of well-positioned MCSs.
• These options include the addition of a fibular strut graft to
enhance support and fixation in the femoral neck, as well
as novel dynamic compression laterally based locking
plates

24. Clinical example of
MCSs/Pauwels screw
augmented with endosteal
fibula allograft. A forty-two-
year-old man with
displaced transcervical femoral
neck fracture. Injury films (left),
immediate postoperative
radiographs demonstrating
anatomic fracture reduction
and fixation with MCS/Pauwels
screw with fibular allograft
construct (middle), and healed
fracture seen 2 years
postoperatively with
maintained anatomic alignment
(right).

25. • To date, there are few alternative methods to enhance
healing of intracapsular femoral neck fractures.
• Meyers introduced the concept of quadratus femoris
muscle pedicle bone graft to enhance vascularity of
the proximal fracture segment, and several authors
have subsequently reported on results of femoral
neck nonunions treated successfully with this
adjuvant technique

26. • In general, basicervical fractures or Pauwels type III fractures and
comminuted fractures can be considered as mechanically unstable,
requiring a load-bearing implant, such as hip screws, with
antirotational screws or intramedullary nails.
• Subcapital or transcervical fracture patterns and noncomminuted
fractures enable load sharing and can be securely fixed with CS or
solitary hip screw systems without compromising fixation stability.
• However, despite all the biomechanical evidence that is available, the
choice of implants for femoral neck fractures in young adults remains
to be controversial

27. Stress Fractures or Insufficiency Fractures
• Management is dependent on fracture location.
• In general, nondisplaced stress fractures of the femoral neck localized
on the compression side may be treated nonoperatively with
protected weight bearing and close observation for 6–8 weeks
• Nondisplaced fractures on the tension side of the femoral neck are at
increased risk for fracture displacement and require internal fixation.
• Endocrine workup and activity modification should be instituted in
the respective populations, similar to compression-sided fractures

28. Displaced Fractures

29. Closed or Open Reduction and Internal
Fixation
If CRIF or ORIF is selected as the operative
management method, it is paramount for a
surgeon to realize that the accuracy of
anatomic reduction is critical; malreduction is
a strong indicator for fracture healing
complications, lower functional recovery, and
subsequent reoperation

30. •The acceptable reduction criteria for
displaced femoral neck fractures is a neck-
shaft angle between 130 and 150 degrees
and 0 and 15 degrees of anteversion.
•Up to 15 degrees of valgus angulation is
acceptable, as it may increase stability
especially in cases with significant posterior
comminution

31. •Conversely, varus angulation, inferior offset,
and retroversion are not acceptable and must
be corrected, as these factors significantly
increase the potential for nonunion, loss of
reduction, and osteonecrosis
•The threshold for open reduction through an
anterior Smith Peterson or anterolateral
Watson Jones approach should be low

32. • For Pauwel type III, basicervical, and highly
comminuted unstable fracture patterns, an SHS offers
greater mechanical stability to resist the increased
shear forces generated and should be used in place of
cancellous screws.
• Use of an antirotational screw or pin to prevent
malreduction during SHS cephalic screw insertion
should be considered ; one should try to achieve a
tip–apex distance #25 mm to minimize potential lag
screw cutout

33. •The Smith-Peterson approach uses the interval
between the sartorius and tensor fascia latae
muscles; it provides excellent exposure of the
anterior femoral neck including the subcapital region
but requires an additional surgical approach to place
internal fixation.
•The Watson-Jones approach uses the interval
between the tensor fascia latae and gluteus medius
muscles and can be used to insert internal fixation
but provides limited exposure of the subcapital
region. It is best used to open reduce more lateral
femoral neck fractures.

34. Smith Peterson Approach
A radiolucent triangle or towel bump under the knee to flex the
hip can relax the hip flexors and make exposure easier

36. Watson Jones Approach

38. Reduction Techniques for
Young Femoral Neck
Fractures
J Orthop Trauma Volume 33, Number 1 Supplement, January 2019
From the Department of Orthopedic Surgery, Wake Forest Baptist
Medical
Center, Winston-Salem, NC.

39. • Current evidence suggests no benefit to emergent
fixation and no increased rates of complication with
delay in fixation
• These fractures most often result in an apex anterior
deformity, with possible posterior comminution and
varus—something the treating surgeon must take into
consideration when considering reduction.
• Radiographs of the contralateral hip can also be
valuable in determining native version and overall
varus/valgus alignment

40. • Understanding that reduction is a surgeon-controlled
variable directly related to outcome, it is critical to achieve
anatomic reduction in these fractures if possible.
• Both the anterior-posterior (AP) and lateral radiographs are
scrutinized for varus/valgus alignment, femoral neck
shortening, and posterior roll off.
• Should any of these variables not align while on the
fracture table with closed manipulation, conversion to
open reduction should be considered.

41. •When performing open reduction, a significant
amount of displacement under direct visualization
can look quite good on intraoperative fluoroscopy.
•Therefore, direct visualization of the fracture
remains the gold standard if an anatomic reduction
is the ultimate goal

42. • With the use of the fracture table, 2 intraoperative
fluoroscopy machines can be used, with 1 machine
positioned in an AP radiograph and the other in a lateral
radiograph to allow ease of provisional and final hardware
placement and to avoid having to “swing through” back
and forth from AP to lateral views.
• Although this takes more time for set-up, once done, the
benefit intraoperatively can be very satisfying for hardware
placement

43. • Multiple k-wires or guide pins can be placed
to the level of the fracture in preparation for
reduction.
• Once the fracture is reduced, the wires can
be driven across the fracture for ease of
maintenance of reduction and not having to
worry about pin trajectory while holding a
potential tenuous reduction

44. Multiple instruments are at the
disposal of the treating surgeon to
help affect reduction and should be
readily available if undertaking
fracture fixation of a young femoral
neck

45. Use of a
femoral
distractor with
one pin within
the pelvis and
the other in
the distal
femur to allow
for length and
rotational
control

46. 3.5-mm tap within the head
segment to act as a joystick
for reduction. Notice
placement of guide pins to
the level of the fracture. Once
reduced, these can then be
driven into position to hold
the fracture provisionally. If
placed appropriately, they can
be used for cannulated screw
placement.

47. A weber clamp placed across the fracture,
allowing for excellent provisional reduction and
compression at the fracture site

48. Use of a collinear
reduction clamp to affect
reduction and gain
compression. Addition of a
pelvic reduction
clamp was used to help
maintain varus/valgus
alignment

49. Use of a Jungbluth clamp
(as well as a schanz pin)
to gain reduction and
compress a femoral neck
fracture.

50. • Once fracture reduction is achieved, provisional to definitive
stabilization occurs.
• Screw fixation is common and is the preferred method of fixation by
surgeons with evidence supporting increased torsional stability,
minimally invasive insertion, and preservation of blood supply
• Screws should not be placed below the level of the lesser trochanter
to decrease stress riser and minimize risk of iatrogenic
subtrochanteric femur fracture.

51. • In the common inverted triangle configuration, the calcar screw to
help resist shear/varus collapse and the superior-posterior screw to
help augment the common posterior comminution to prevent apex
anterior deformity
• In addition, because many young femoral neck fractures are high
Pauwel angle fractures prone to shear force, the addition of a screw
perpendicular to the fracture can be used ( SEE NEXT SLIDE )

53. • This allows for improved compression at the fracture site
because it is directed perpendicular to the main fracture line
but also helps resist the shear forces and varus collapse of
higher angle femoral neck fractures.
• As such, this is often the first screw to be placed and is
partially threaded to provide a lag screw by design to the
fracture in high Pauwel angle fractures

54. • A fracture which is in slight varus or valgus or with slight gapping may
be able to be pulled into a more anatomic position by placement of a
well-positioned partially threaded screw first as compression occurs
inevitably, pulling the head into a more varus or valgus position
• Fully threaded screws can be used in cases where the surgeon wishes
to prevent the “collapse” and keep reduction length because the
threads on either side of the fracture, in theory, do not allow sliding
and should maintain length

55. • More vertical femoral neck fractures is a fixed angle construct (such
as a sliding hip screw or dynamic blade).
• Maintenance of an anatomic reduction to keep the abductor moment
and hip biomechanics aligned is an important functional factor and
outcome measure.
• Placement of the fixed angle construct necessitates a lateral incision
for introduction of hardware in addition to the anterior reductive
portal.

56. • Optimal position of the sliding hip screw/cephalomedullary device is
centered within the femoral head on both the AP and lateral views,
although it can also be used as a “calcar screw” of an inverted triangle
with the addition of screws above along the anterior superior and
posterior superior femoral neck

57. • When driving the guide pin into the femoral head, it is important to
ensure that the correct angle guide is used based on preoperative
planning to fit the patient’s native varus/valgus orientation and the
guide maintains direct contact onto the femur.
• If this is not done, placement of the final plate will induce either a
varus or valgus deformity and malreduce the fracture as the plate is
brought into contact with the bone

58. • The use of a derotation screw can be placed to help hold the
reduction as, even with multiple k-wires, the power of the screw can
often still cause deformity.
• This screw is often (but not always) a 6.5-mm partially threaded screw
placed directly superior to the sliding hip screw to gain further
compression at the fracture site.
• Care must be taken when placing the sliding hip screw to make sure
there is enough room superiorly, should this derotation screw be
necessary
• The surgeon may consider removal of this screw after insertion
because no further stability in fixation is seen after the sliding hip
screw is seated

59. • Another technique to help avoid rotational deformities with
placement of the screw is the use of a blade device instead of a
screw.
• With this technique, the blade rifles into position via the barrel as
opposed to a rotational/screw moment to rotate the femoral head
• However, as the blade is hammered into position, the surgeon risks
gapping the fracture and distraction on final seating of the implant

60. ADJUNCTIVE REDUCTION TOOLS
• An anterior femoral neck platecan be placed in a buttress fashion
along the calcar at the apex of the fracture.
• This plate can help reduce the fracture via an antiglide effect but also
help minimize and reduce the shear forces so dominant within this
fracture pattern.
• The plate may also be placed along the anterior neck to help reduce
and neutralize the apex anterior deformity of the fracture
• The plate is often placed after provisional reduction is achieved but
before definitive placement of the sliding hip screw.

62. The CONQUEST System
• A new technology and system developed to help solve this difficult
fracture pattern is the Conquest device developed by Smith and
Nephew
• This device attempts to bring much of the theory behind other
fixation constructs/technology together
• The Conquest uses an inverted triangle of partially threaded screws
that are designed as compressible, telescoping/sliding screws,
allowing for controlled collapse at the fracture site while fracture
resorption occurs. In addition, the screws lock into a side plate, which
give an “intact” lateral wall and buttress against collapse, providing
both strength and preventing screw back out as the controlled
fracture collapse occurs

63. The
CONQUEST
System

66. Aesculap Targon system

67. Some Case Pictures

71. Replacement Surgeries

72. •Arthroplasty (HA and total hip replacement) is
the treatment of choice for most older
individuals who sustain a displaced femoral neck
fracture
•Cemented femoral stems remain the standard
of care with good long-term results

73. There is evidence, however, that uncemented
stems are at an elevated risk for intraoperative
and postoperative periprosthetic fracture;
furthermore, some studies report increased pain
and poorer functional outcomes with the use of
uncemented stems compared with cemented
stems for the treatment of femoral neck fractures
in the elderly

74. It is important to recognize that when
compared with HA, total hip replacement
necessitates a more extensive exposure
for implantation with higher blood loss
and increased potential for perioperative
complications

75. •Potential issues with modular neck and head
designs is the possibility of trunnionosis and
component dissociation at the head–neck and
neck–stem interfaces.
•Although these complications are rarely
encountered, they may be considered in cases
with new onset hip pain or dysfunction after
arthroplasty