In proximal humerus fractures in elderly patients, more than 50% have fair or poor results because of screw loosening and pullout from the humeral head.13 Internal fixa-tion of intertroc
Trang 1Osteoporosis is a systemic disease
characterized by decreased bone
mass and deteriorated bone
microar-chitecture In the elderly (≥65 years),
it is a contributing factor in 75% of
fractures caused by low-energy
falls.1 Fractures resulting from
os-teoporosis generally involve the
metaphyseal regions of the skeleton
These regions are affected earlier
and more profoundly during the
de-velopment of osteoporosis because
they are composed mostly of
cancel-lous bone, which has a greater
sur-face area for bone turnover
com-pared with the compact cortical bone
of the diaphysis
In the United States, 1.5 million
fractures are reported annually,
most from low-energy falls,
includ-ing 300,000 proximal femur
frac-tures, 250,000 distal radius fracfrac-tures,
and 300,000 fractures in other bones
affected by osteoporosis Of the 28
million Americans with osteoporo-sis, 80% are women Fifty percent
of women and 18% of men older than 50 years will sustain an osteo-porotic fracture.1 Although $13.8 billion is spent annually to manage these fractures, <50% of hip fracture patients recover fully after treat-ment.2,3 These statistics emphasize the need for skilled fracture care for osteoporotic patients Reasonable return of function in the elderly requires solid internal fixation and rapid initiation of rehabilitation
Conversely, inadequate fixation or prolonged immobilization with nonsurgical care increases the risk
of thromboembolic disease, pul-monary complications, decubitus ulceration, and generalized muscu-loskeletal deterioration from which complete recovery is unlikely
Achieving stable internal fixation for fractures in osteoporotic bone
can be problematic but is central to effective care
Fracture Management in Osteoporotic Patients
The goal of definitive fracture care
in elderly patients is early restora-tion of funcrestora-tion Treatment should
be timely; generally, these patients are in the best condition to undergo surgery within the first 48 hours after injury.4,5 Nevertheless, the presence of concurrent illness re-quires thorough evaluation before surgery Preoperative management
to optimize the patient’s condition
or correct any decompensation resulting from the injury can benefit survival.5 Procedures should be kept as simple as possible to mini-mize surgical time, blood loss, and physiologic stress Early weight bearing is possible only after suc-cessful stable fracture fixation in the lower extremity Although
anatom-ic restoration is important for intra-articular fractures, metaphyseal
Dr Cornell is Associate Attending Ortho-paedic Surgeon, Hospital for Special Surgery, New York, NY.
Reprint requests: Dr Cornell, 535 East 70th Street, New York, NY 10021.
Copyright 2003 by the American Academy of Orthopaedic Surgeons.
Abstract
Because of the decreased holding power of plate-and-screw fixation in osteoporotic
bone fractures, internal fixation can have a high failure rate, ranging from 10% to
25% Screws placed into cortical bone have better resistance to pullout than do
those placed into adjacent trabecular bone Plates should not be used to bridge
unstable regions of bony comminution in osteoporotic patients Fixation stability
is optimized by securing stable bone contact across the fracture site and by
plac-ing screws both as close to and as far from the fracture as possible Intentional
shortening can improve stability and load sharing of the fracture construct.
Structural bone graft or other types of fillers can be used to fill voids when
com-minution prevents stable contact Load-sharing fixation devices such as the
slid-ing hip screw, intramedullary nail, antiglide plate, and tension band constructs
are better alternatives for osteoporotic metaphyseal locations Proper planning is
essential for improved fracture fixation in this high-risk patient group.
J Am Acad Orthop Surg 2003;11:109-119
Patients With Osteoporosis
Charles N Cornell, MD
Trang 2and diaphyseal fractures are best
managed by attempts to primarily
achieve stability rather than
ana-tomic reduction
Appropriate treatment of
frac-tures secondary to osteoporosis
re-quires understanding the effect of
the disease on the material and
structural properties of bone, as well
as any effect on the process of
frac-ture healing Decline in the capacity
for fracture repair is age related.6
Disturbance of the development of
strength within fracture callus in the
elderly has been shown in
ex-perimental rat models,7but little is
known about the causes of
osteo-porosis and its effect on the fracture
repair process in humans.8
None-theless, impaired fracture healing in
osteoporotic patients is assumed
The principles of biologic fracture
repair should be applied whenever
possible.9 Careful handling of the
surrounding soft tissues and
avoid-ing unnecessary strippavoid-ing of fracture
fragments preserve blood supply to
the fracture site Minimizing
ex-posure of the fracture with
preserva-tion of the fracture hematoma may
speed development of callus
Bone failure, not implant
break-age, is the primary mode of failure
of internal fixation in osteoporotic
bone Because bone mineral density
correlates with the holding power of
screws, osteoporotic bone often
lacks the strength to hold plates and
screws securely.10-12 Furthermore,
comminution can be severe in
osteo-porotic fractures Surgical treatment
of fractures of the proximal humerus,
proximal and distal femur, and
proximal tibia has resulted in an
increased incidence of poor results
in elderly, osteoporotic patients In
proximal humerus fractures in
elderly patients, more than 50%
have fair or poor results because of
screw loosening and pullout from
the humeral head.13 Internal
fixa-tion of intertrochanteric fractures
fails in 10% of cases because of
cutout of the lag screw from the
cancellous bone of the femoral head.14 Although open reduction and internal fixation yields results superior to those of nonsurgical management for supracondylar femur fractures, 25% of patients treated with the angled blade plate have fair to poor results because of loss of reduction caused by loosen-ing of the implant in the osteoporotic bone of the femoral condyles.15,16
Traditional internal fixation tech-niques must be modified to achieve satisfactory results in osteoporotic bone Internal fixation devices that allow load sharing with host bone should be used to minimize stress at the bone-implant interface Sliding nail plate devices, intramedullary nails, antiglide plates, and tension band constructs are better than more rigid techniques to treat osteo-porotic bone fracture
Implant Fixation in Osteoporotic Bone
Screws
Resistance to pullout of a screw placed in bone depends on the length of the screw purchase, thread diameter, and quality of the bone into which it is inserted Recent studies also have indicated that the trabecular orientation within the bone is important Bone is highly anisotropic Screws placed parallel
to the trabecular pattern have greater pullout strength than do those placed across the trabeculae.17 The variable of bone quality becomes the prime determinant of screw holding power in osteoporotic bone.17,18
When bone mineral content falls below 0.4 gm/cm2, the effect of varying thread diameter is lost.18
Therefore, a plan to place screws into osteoporotic bone should be designed to place them as parallel as possible to the cancellous trabeculae
Also, the screws should have the largest thread diameter compatible with the scale of the fracture being
repaired Most importantly, if possi-ble, screws should be placed to secure fixation into cortical bone Cortical bone has greater mineral density and, therefore, greater resis-tance to screw pullout than does the adjacent trabecular bone Thus, in poor quality bone, a smaller diame-ter cortical screw may be betdiame-ter than
a larger diameter cancellous screw that does not secure cortical pur-chase
In cases of severe osteoporosis, screw fixation may be augmented with polymethylmethacrylate (PMMA).16,19,20 Although PMMA has relatively poor adhesion to bone, its intrusion into the cancel-lous structure results in a much stronger composite after the cement polymerizes One screw fixation augmentation technique21 begins with removal of any screws that have inadequate purchase or have stripped with tightening The PMMA powder and liquid should
be cooled to slow polymerization Once the components are mixed, the liquid cement is placed into a 10-mL syringe with the tip widened
by drilling it out with a 3.5-mm drill The cement then can be in-jected into the stripped screw holes, and the screws replaced but incom-pletely tightened The screws are fully tightened once the cement has set (Manipulation of the screw while the cement is setting loosens the bond between the cement, bone, and screw, lowering the pullout strength.) Struhl et al19 described an alternative method similar to ce-ment techniques used for fixation of intramedullary prostheses The medullary canal is blocked proxi-mal and/or distal to the fracture site, and the entire medullary cavity
is filled with cement After the frac-ture is reduced and the cement has cured, the screws are inserted by drilling and tapping Screws placed during the curing process are tight-ened once the cement has cured This technique is very useful when
Trang 3poor screw fixation is combined
with significant bone loss
Plates
The strength of plate fixation is
directly affected by the degree of
comminution and the resulting size
of any gap at the fracture site In
addition, the pattern of screw
place-ment influences the strain
experi-enced within the plate and its
screws.22,23 The most important
fac-tor that reduces strain in plated
frac-tures is the degree to which cortical
contact can be achieved at the
frac-ture site Experimental fracfrac-tures
stabilized by plates spanning a gap
had three times the strain of
frac-tures stabilized with secure cortical
contact.23 Additionally, for a given
fracture pattern, the screw spacing
is more important than the number
of screws used for fixation.22 Strain
within a plated construct is least
when screws are placed both as
close to and as far from the fracture
site as possible In two-part
frac-tures or those with solid cortical
contact, the farther the screws are
placed from the fracture, the less the
strain experienced within the plate
Thus, in longer plates with screws
placed as close to and as far as
pos-sible from the fracture site,
interven-ing screws add little to overall
fixa-tion strength In comminuted
frac-tures or those with a gap, the longer
plate retains its advantage, but an
increased number of screws
adja-cent to the fracture site reduces the
strain within the plate Ellis et al23
concluded that three screws should
be placed in the holes adjacent to
either side of the fracture gap as
well as the most distant hole of the
plate, since additional intervening
screws add little to the load
experi-enced by the plate
Longer plates with widely spaced
screws should be used in osteoporotic
bone Cortical contact at the fracture
site is paramount; if moderate areas
of comminution exist, the fracture
should be shortened to achieve
con-tact, especially in the cortex opposite the plate.15,16 Plates should not be used to bridge gaps in osteoporotic bone but should be used as tension bands, which require an intact, load-sharing cortex opposite the plate
When comminution is extensive and prevents stable contact opposite the plate, double-plating should be con-sidered to secure stability In addi-tion, the plates should be placed to act as antiglide plates whenever pos-sible, especially in short oblique or spiral oblique fracture patterns In such situations, the plate can be posi-tioned to create an axilla with the cor-tex at the apex of the oblique tongue
of the fracture (Fig 1) The plate position acts to prevent fracture dis-placement, placing less importance
on screw fixation within the weak,
adjacent metaphyseal bone It also positions the plate for insertion of lag screws, which are important to treat the oblique fracture pattern
Intramedullary Nails
Intramedullary nail fixation is well suited for diaphyseal fractures
in osteoporotic bone and is the treat-ment of choice for diaphyseal frac-tures of the femur and tibia.24 The nails provide broad areas of pur-chase, allow load sharing, and offer sufficiently secure fixation to allow immediate weight bearing in many circumstances.25 The development
of interlocking nails has extended the indications for intramedullary nailing to include metaphyseal frac-tures Intramedullary nails are posi-tioned closer to the mechanical axis
Figure 1 The antiglide fixation method A, Direction of the fracture displacement (arrow).
B, The plate is positioned to create an axilla at the apex of the fracture, and the distal
frag-ment reduces into the axilla The arrows indicate the corrective force exerted by the plate.
C, The plate minimizes the tendency for displacement and achieves compression along the
fracture line (arrows) Strong screw fixation in the diaphysis of the proximal fragment holds the reduction (arrows) and makes the distal screws unnecessary Placement of the plate in the plane of the fracture obliquity makes it easy to place a lag screw through the plate (Adapted with permission from Carr JB, Trafton PG: Malleolar fractures and soft tissue injuries of the ankle, in Browner BB, Jupiter JB, Levine AM, Trafton PG [eds]:
Skeletal Trauma, ed 2 Philadelphia, PA: WB Saunders, 1998, vol 2, pp 2327-2404.)
Trang 4of the bone and, as a result, are
sub-ject to smaller bending forces than
are plated constructs placed on the
external surface of the bone
Fa-tigue failure is less likely with
intramedullary nails than with plate
constructs Mechanically locked
in-tramedullary nails provide greater
strength in axial loading than do
condylar blade plates but are
mark-edly less stable during bending and
torsion when used in the distal
femur.26,27 Thus, although locked
nails provide less stability than do
condylar blade plates in simple,
metaphyseal fractures, they are
bet-ter suited for fixation of severely
comminuted osteoporotic bone
frac-tures with no reconstructable medial
buttress
The major weakness of locked
intramedullary nails is the security
of the locking screws, which may
loosen in osteoporotic metaphyseal
bone This is particularly likely in
the bone of the distal femur and can
lead to loss of control of the distal
fragment, which often results in
ro-tational and varus/valgus
malalign-ment Locking screw fixation can be
improved by using different planes
of screw orientation (eg,
anteropos-terior and transverse placement),28
by using osteoporotic nuts and
washers on the medial side of the
femur where the locking bolts emerge,
or by using cement to improve
fixa-tion.16
Tension Band Wiring
Tension band wiring is usually
applied to transverse fractures,
which are distracted by the pull of
attached tendons and ligaments
This technique provides strong and
secure fixation, which allows
im-mediate mobilization of involved
joints Fractures of the olecranon and
patella can be successfully treated
with this method The tension band
wire has additional advantages in
osteoporotic bone In metaphyseal
locations, such as the proximal
humerus or medial malleolus,
ten-don and ligament insertions to bone can provide better strength for fixa-tion than does the bone itself In these areas, placement of tension band wires within the soft-tissue attachments can provide excellent anchorage Hawkins et al29
report-ed better clinical results with ten-sion band wiring than with plate-and-screw fixation in proximal humerus fractures A similar tech-nique can be used to secure ex-tremely osteoporotic or comminuted medial malleolar fractures (Fig 2)
The fracture is reduced and
main-tained with small Kirschner wires The tension band wire is passed within the fibers of the deltoid liga-ment and proximally secured to bone by passing it around a screw placed through the tibia The wire is placed in figure-of-8 fashion and can
be tightened by opposing twists Tension band wires also can supple-ment plate-and-screw fixation in fractures that may be subjected to tensile loading After securing the fracture with plate and screws, a tension band wire is passed within adjacent tendinous attachments and beneath the plate to help neutralize tensile forces across the construct (Fig 3)
Augmentation
Bone grafting plays several important roles in the treatment of osteoporotic fractures Cancellous bone graft can be used to augment
or encourage rapid fracture healing Cancellous bone is osteoinductive, osteoconductive, and osteogenic,30
and it can stimulate new bone for-mation periosteally in fracture gaps created by comminution There is
no evidence that osteoporotic bone
is an inferior graft material
Corticocancellous bone graft can
be used in osteoporotic fractures
to replace regions of skeletal loss caused by comminution or crush, thus enhancing fracture construct stability This is especially true for metaphyseal and joint depression fractures, such as split-depression tib-ial plateau fractures, intra-articular fractures of the distal radius, distal humerus fractures, and tibial plafond fractures Surgical repair requires elevation of the articular surface to restore joint congruity with the use
of structural bone graft to fill in the metaphyseal void and provide sup-port to the subchondral region The iliac crest is the most com-mon donor site for autogenous bone graft The morbidity associated with the harvest of autogenous bone is a concern,31especially in the
Figure 2 Tension band wiring Kirschner
wires are placed to hold the medial malleo-lus fracture reduced A figure-of-8 wire is then passed distal to the wires through the substance of the deltoid ligament and anchored to a screw placed proximal to the fracture (Adapted with permission from Carr JB, Trafton PG, Simpson LA:
Fractures and soft tissue injuries of the ankle, in Browner BD, Jupiter JB, Levine
AM, Trafton PG [eds]: Skeletal Trauma, ed
2 Philadelphia, PA: WB Saunders, 1998, vol 2, pp 1871-1957.)
Trang 5elderly In older osteoporotic
indi-viduals, the quantity and quality of
bone available at the iliac crest is
often insufficient, requiring a larger
exposure, which increases the risk
of donor site complications Bone
graft substitutes can provide an
at-tractive alternative to autograft in
osteoporotic patients.32 Bone graft
substitutes include allograft bone,
demineralized allograft bone
prod-ucts, and synthetic osteoconductive
materials, which can be used as
bone void fillers Several of these
products have been shown to be
essentially equivalent to autogenous
graft for treatment of acute
frac-tures.33,34
Replacement of severely
com-minuted areas with PMMA to
re-gain stablility is sometimes required
after severe skeletal loss It has been
used successfully, especially in
supracondylar fractures of the femur16,19and intertrochanteric frac-tures However, PMMA is not an ideal material for this purpose because it is a permanent implant and a foreign body within bone It also generates considerable heat with polymerization, which may be harmful to bone and surrounding soft tissue Cements made from cal-cium phosphate adhere better to bone and have the advantage of being resorbed and replaced by host bone These cements are not used
to augment screw fixation but to fill voids caused by comminution or severe osteoporosis Calcium phos-phate cements have been useful in intertrochanteric and distal radius fractures.35,36 These new cements can provide enough support to allow earlier load bearing and decrease the dependency on inter-nal fixation devices
PMMA can be used to augment screw purchase in the severely osteoporotic diaphysis, but another useful approach is to place an aug-mentation device into the medullary canal to incorporate as bone or be resorbed Fibular allograft struts are used for this purpose (Fig 4)
The fibular strut improves local bone stock for screw purchase and can be incorporated to provide a span across regions of diaphyseal deficiency Creative strategies such
as these can be extremely successful for treating osteoporotic diaphyseal fracture and nonunion
Fracture Types
Intertrochanteric Fractures
The sliding hip screw (SHS) has markedly advanced the treatment of intertrochanteric fractures.37,38 The success of the SHS is based on its design, and in many ways it is the ideal device for this typically osteo-porotic fracture The SHS has a lag screw that gains broad purchase in the highest quality bone in the
fem-oral head The dynamic slide of the lag screw and side plate allows impaction at the fracture site with load sharing along the plane of the fracture The success of load shar-ing is evident in that the length of the side plate makes little difference
in the stability of an SHS con-struct.39 When the SHS is inserted correctly, in all but the most unsta-ble fractures the failure rate of fixa-tion is <5%, even in extremely os-teoporotic patients.14,40 The most important aspect of SHS insertion is
to ensure that the lag screw is placed in the center of the femoral head (within 10 mm of the femoral head apex in both the anteroposte-rior and lateral radiographic views)
Figure 3 Anteroposterior radiograph of a
tension band wire augmenting plate
fixa-tion in the proximal humerus The wire is
passed in figure-of-8 fashion beneath the
supraspinatus tendon and distally beneath
the plate (arrow) The wire provides a
strong purchase and acts to neutralize the
deforming pull of the rotator cuff.
Figure 4 Anteroposterior radiograph of a
repair of a humeral nonunion with seg-mental bone loss A fibular strut allograft was fashioned into an intramedullary peg.
It spanned the defect and improved the screw purchase proximal and distal to the fracture site The loose distal screw was hidden within soft tissues left from a prior attempt at reconstruction.
Trang 6Additionally, the lag screw must be
able to slide within the side plate
barrel to allow stable impaction at
the fracture site To this end, the
side plate angle should be ≥135°
With a short lag screw, a
short-bar-rel plate should be used to assure
adequate slide Generally, a
short-barrel side plate should be used
when the lag screw is <85 mm The
surgeon should ensure that 10 mm
of slide can occur
Unfortunately, similar success
does not occur with unstable
four-part fractures, reverse obliquity
fractures, or fractures with
sub-trochanteric extension because the
lack of a lateral buttress and the loss
of the posteromedial bone for load
sharing prevents them from
dynam-ically achieving stability.41 As a
result, the SHS allows maximum medial displacement of the shaft, leading to either unacceptable short-ening at the fracture site or cutout of the lag screw from the femoral head because the lag screw threads have come to rest on the barrel of the side plate (Fig 5) In these unstable frac-ture patterns, devices are needed to recreate a lateral buttress or allow vertical, dynamic impaction Fixed-angle devices such as the 95° condy-lar screw can be used.42 This type of device provides a lateral buttress, but because it has a fixed angle, it cannot load-share unless an intact medial buttress can be reconstituted
Failure is almost guaranteed with-out this medial support opposite the plate (Fig 6) Additionally, these devices do not allow weight bearing immediately after surgery
Alternative devices for treating unstable peritrochanteric fracture include the intramedullary hip screw (Gamma nail) and vertically sliding plate The intramedullary SHS provides the advantages of an intramedullary nail combined with a dynamic hip screw that allows impaction of the peritrochanteric fracture.25,43 The intramedullary position decreases the lever-arm on the device and creates its own lateral buttress that prevents excessive lat-eral migration of the proximal frag-ment The strength of the device allows immediate weight bearing
Use of the long intramedullary nail helps avoid fracture of the femoral shaft that can occur when the short Gamma nail is used The insertion
of intramedullary hip screws can be technically demanding because the fracture must be reduced before reaming and nail insertion to avoid comminution of the fracture site and adjacent cortex Open reduction be-fore nailing is recommended unless
a nearly perfect closed reduction can
be achieved
The vertical SHS allows fractures
to impact without excessive lateral displacement (Fig 7) Although
clinical experience with these de-vices is preliminary, initial results are encouraging.44 The primary advantages of this device are the ease with which it can be inserted as well as its use to salvage an SHS that has been complicated by lateral cortex comminution during inser-tion
Supracondylar Fractures
of the Distal Femur
Osteoporosis weakens the supra-condylar region of the distal femur in the elderly, allowing even low-energy injuries to result in complex fractures Intra-articular involvement and minution of the metaphysis is com-mon in this population The
chal-Figure 5 Anteroposterior radiograph of a
reverse obliquity fracture pattern A
slid-ing hip screw was used to stabilize the
frac-ture, which lacks a stable lateral buttress.
Without a lateral buttress, the dynamic
slide of the plate could not achieve stability.
The proximal fragment displaced until no
further slide could occur, so the dynamic
hip screw became a fixed-angle,
load-bear-ing device As a result, the lag screw cut
out of the femoral head.
Figure 6 Anteroposterior radiograph of a
subtrochanteric fracture treated with a 95° dynamic condylar screw plate A defect in the medial cortex persisted after recon-struction The plate acted as a bridge plate rather than a tension band, which resulted
in loosening of the screws of the side plate, with loss of reduction of the fracture.
Trang 7lenge of treating these fractures led
to the development of closed
treat-ment methods using traction and
cast bracing, but those techniques
resulted in loss of range of motion
The development of internal
fixa-tion methods for these fractures has
allowed restoration of anatomy and
early knee rehabilitation
Many features make the 95°
blade plate designed for
supra-condylar fractures ideal for fixation
in osteoporotic bone Retrograde
intramedullary nails do not provide
the same stability as do the 95°
devices26,27,45 and should be
re-served for fractures around total
knee replacements,46those with
se-vere comminution into the
diaphy-sis, or those with severe skin
com-promise around the knee The 95°
condylar screw was designed to make insertion of the device easier compared with the blade plate
However, it sacrifices more bone from the distal femur with insertion and cannot be as easily revised It is also slightly larger and can impinge
on the lateral soft tissues of the knee In contrast, the blade plate is low profile and requires very little bone sacrifice; also, the position of the blade can be revised without compromising fixation However, the blade plate is more technically demanding to insert
Although the blade plate can be used successfully as a bridging plate
in younger individuals with good bone stock, it should be used only
as a tension band in the elderly
This requires reconstitution of a load-sharing medial femoral cortex opposite the blade plate For many fractures, this can be accomplished
by shortening the fracture into a position of stability by impacting the fracture surfaces Shortening of
as much as 1 to 2 cm can be done without notable loss of function.15
Healing is usually rapid after short-ening because the comminuted medial bone functions as bone graft.16 In severely comminuted fractures in which sufficient stability cannot be accomplished by shorten-ing, the surgeon can resort to dou-ble plating the distal femur47or replacing the region of bone loss with cement
Lateral Tibial Plateau Fractures
The split-depression or Schatzker type II (AO classifications B2 and B3) is the most common lateral tibial plateau fracture in the osteoporotic patient Fractures with <5 mm of joint surface depression in a patient with a knee that is stable to varus/
valgus stress can be managed non-surgically Surgical reconstruction
is required if the degree of joint depression is >5 mm and if there is
>5° of varus/valgus instability The
surgical technique for repair of the split-depression lateral tibial pla-teau fracture has been reported extensively.47,48 Benirschke et al49
suggested modifications of this technique that call for use of a small fragment plate specifically designed for the lateral tibial plateau The small fragment plate is low profile and allows placement of proximal screws very close to the subchon-dral plate of the reduced tibial pla-teau As many as four screws can
be inserted, providing extensive support of the reduced joint surface The small screws can be placed into opposing cortex to secure cortical purchase without the risk of soft-tis-sue irritation associated with pro-truding large fragment cancellous screws Because the screws placed under the subchondral bone are reminiscent of rafters supporting a roof or a floor, this has been referred
to as the rafter plate technique (Fig 8) This modification of the stan-dard technique is useful for the os-teoporotic patient.49
Insertion of a bone graft to fill the metaphyseal defect created after elevation of the joint surface is stan-dard, but substitution of other osteo-conductive materials, such as calcium phosphate cements and
hydroxy-Figure 7 Anteroposterior radiograph of a
sliding hip screw with vertical slide
capa-bility This plate was chosen after
attempt-ed insertion of a standard side plate
result-ed in comminution of the lateral cortex
around the lag screw insertion site The
vertical slide allows axial settling in this
unstable fracture pattern Stable bone
con-tact is achieved without excessive lateral
displacement of the head and neck.
Figure 8 The rafter plate technique Four
3.5-mm screws are inserted through a cus-tom plate and placed close to the subchon-dral plate, providing a broad area of sup-port (Adapted with permission from Benirschke SK, Swiontkowski MF: Knee,
in Hansen ST Jr, Swiontkowski MF [eds]:
Orthopaedic Trauma Protocols New York,
NY: Raven Press, 1993, pp 291-329.)
Trang 8apatite implants, has proved to be
successful.33
Ankle Fractures and
the Distal Fibula
Ankle and foot fractures are
among the most common fractures
sustained by women, and most ankle
fractures occur in women aged 75 to
84 years The prognosis for ankle
fractures is worse in the elderly than
in younger individuals, but the
treat-ment principles are identical.50 Even
small amounts of residual
displace-ment in the mortise markedly alter
the load-bearing distribution on the
talus, leading to poor clinical
out-comes.51,52 As in younger patients,
ankle fractures must be treated with
anatomic reduction until healing
Isolated fractures of the lateral
malleolus without injury to the
medial malleolus or deltoid
liga-ment can be treated nonsurgically,
whereas unstable ankle fractures
require open reduction and internal
fixation Surgical fixation of the
ankle in the elderly can be made
more difficult by poor skin
integ-rity, swelling, diabetes, and vascular
disease In addition, bone loss from
an osteoporotic lateral malleolus
can compromise the ability to
se-cure internal fixation of the lateral
aspect of the ankle Most lateral
malleolar fractures are short oblique
or spiral oblique patterns, with the
apex of the fracture posterior and
proximal The most accepted
fixa-tion technique is placement of a
plate on the lateral surface of the
malleolus through a lateral incision
Modifying this technique by placing
the plate on the posterior surface of
the fibula puts it in the antiglide
position, which results in superior
biomechanical performance53(Fig 9)
Additionally, with the plate placed
posteriorly, the skin incision can be
more posterior, allowing for better
coverage of the fibula if
wound-healing problems occur The best
advantage of the antiglide position
is that the purchase of the distal
screws is relatively unimportant; the important screw fixation is in the more proximal cortical region of the fibula The antiglide principle can
be applied to any oblique fracture, especially medial tibial metaphyseal fractures and spiral oblique fractures
of the distal tibial metaphysis
Proximal Humerus Fractures
Proximal humerus fractures com-monly occur in elderly women; for-tunately, 80% of these fractures are impacted or minimally displaced and heal with a brief period of im-mobilization Unstable fractures displace because of the pull of the musculature attached to the upper humerus If not reduced, they will result in malunion, with loss of range of motion, strength, and func-tion of the shoulder girdle Loss of shoulder motion can diminish the ability to dress and attend to per-sonal hygiene Poor functional out-come after a proximal humerus frac-ture in the elderly can markedly reduce social independence Open reduction and internal fixation of unstable two- and three- part frac-tures of the humerus leading to im-proved functional outcome is ad-vantageous in the elderly
Repair of proximal humerus frac-tures is extremely challenging, and results are often disappointing even with experienced surgeons Pros-thetic replacement of the humeral head is indicated in three- or four-part fractures in which the head is only a deficient shell of subchondral bone However, functional results
of two- and three-part fractures are better if open reduction and preser-vation of the humeral head can be done.29 Plating of the proximal hu-merus is often unsatisfactory be-cause of poor screw purchase and acromial impingement caused by the bulkiness of the hardware.13,54
Hawkins et al29 first described the advantage of tension band fixation for such fractures after recognizing that the tendinous attachment of the rotator cuff to the tuberosities pro-vides excellent purchase for figure-of-8 wires The tendon provides better anchorage than does the soft bone of the humeral head, and the reduced bulkiness of wire con-structs makes tension band fixation ideal for this region Excellent clini-cal results are possible with modifi-cations of Hawkins’ original tech-nique, which involves exposure of the fracture site through an
extend-ed deltopectoral approach.54-56 The fracture is mobilized and the head and shaft are impacted to achieve stability along the fracture site Intramedullary nails or a simple lag screw can be placed to provide ini-tial stability while the tension band wires are positioned One is placed under the rotator cuff tendons, and
a second can be used to wire the tuberosities together The wires are attached to the shaft through a drill hole placed lateral through the shaft (Fig 10) The stability of this con-struct allows immediate shoulder rehabilitation, thereby optimizing outcome
Extensive metaphyseal com-minution, which would lead to excessive shortening with impaction
at the fracture site, precludes use of
Figure 9 Lateral radiograph of a lateral malleolar fracture stabilized with a plate placed in the posterior or antiglide position.
Trang 9this technique alone Such
shorten-ing can cause subluxation of the
shoulder because of laxity in the
deltoid muscle In these cases, a
plate should be used to restore and
maintain proper height A modified
cloverleaf plate works well because
it is small, can be used to place
mul-tiple screws into the head, and can
be supplemented with a tension
band wire for added support
Re-cently, interlocking proximal
hu-meral nails and blade plates have
been advocated for these fractures
Proximal humeral plates with
fixed-angle screws also have been
intro-duced Although these devices are
promising, clinical experience has
yet to be reported
Postoperative Care
Postoperative care of patients with
osteoporotic fracture should include
both physical rehabilitation and
psy-chosocial treatment Many elderly patients have marked preinjury functional compromise, and the additional disability associated with recovery makes short-term rehabili-tation necessary for most before eventual return home Depression and hopelessness are common in the elderly after injury and must be addressed by the health care team
These patients are best treated by a multidisciplinary service in which their medical, psychological, and social concerns are addressed Many elderly patients enter the hospital in
a malnourished state and therefore have a high mortality rate Malnu-trition results in immunocompro-mise and is associated with higher complication rates for fracture sur-gery.57 Clinical evaluation of nutri-tional status can easily be done by assessing the patient’s dietary habits and measuring the serum albumin
A serum albumin <3.5 mg/dL indi-cates chronic protein malnutrition
Elderly patients may have diffi-culty complying with restricted weight bearing after surgery on the lower extremity and should be allowed to bear weight as tolerated with a walker Because load sharing
is the most important principle of osteoporotic fracture surgery, weight bearing as tolerated is not contraindi-cated postoperatively Most elderly patients will not adhere to partial weight-bearing protocols; therefore,
no weight bearing is recommended
if there is uncertainty about the sta-bility of the fracture construct Finally, it should be assumed that any patient past middle age with a low-energy metaphyseal fracture has osteoporosis These patients should undergo bone mineral den-sity testing and be placed on a regi-men to combat further bone loss They should be encouraged to take calcium 1,000 to 1,500 mg/d with a multivitamin to ensure adequate vi-tamin D intake Elderly fracture
Figure 10 Anterior (A) and lateral (B) views and anteroposterior radiograph (C) of the tension band technique used to treat proximal
humerus fractures A preliminary lag screw impacts the fracture and maintains reduction, then two tension band wires are placed The first wire is passed beneath the supraspinatus tendon, and the second through the tuberosities The figure-of-8 wires are passed through a drill hole in the shaft This construct takes advantage of the strong rotator cuff tendinous insertion and permits immediate postoperative rehabilitation of the shoulder.
Wire 1
Wire 1 Wire 2
Wire 2
B
Trang 10tients also should be encouraged to
start bisphosphonate therapy
be-cause alendronate has been proved
to reduce the risk of additional
frac-tures after hip fracture.58 Treatment
of the underlying osteoporosis is
part of the fracture treatment
Summary
Fracture care techniques often
require modification to be useful to
treat osteoporotic bone Screws
should be placed into the
best-quali-ty-bone available, which is usually
an opposing cortex Screw fixation
can be augmented by using PMMA
With plate fixation, stable bone con-tact at the fracture site is the most important factor for reducing strain
in the plate Shortening of the af-fected bone can achieve this contact
in comminuted fractures Plates should not be used to bridge areas of comminution in osteoporotic bone and should be as long as possible, with screws placed close to and far from the fracture site Locked intramedullary nails can be used for diaphyseal fractures or fractures with metaphyseal-diaphyseal comminu-tion Angled blade plates are very applicable to osteoporotic
metaph-yseal fractures but should be used as tension band plates that require sta-ble, load-sharing contact opposite the plate Antiglide plating and use
of tension band wires also are effec-tive strategies for osteoporotic frac-tures Use of bone graft substitutes is particularly applicable to reduce the morbidity of bone graft harvest and ensure adequate volumes of graft in the elderly Patients with evidence
of osteoporosis should be started on
a medical regimen that includes cal-cium supplementation with a pre-scription for bisphosphonates or other antiresorptive regimes to com-bat further bone loss
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