Abstract book 6th RMS 16.indd

294
Surgical Treatment of Osteoporotic
Fractures
Peter V. Giannoudis MD, Orthopedic Surgery (UK)
The major technical problem facing the
surgeon when dealing with osteoporotic
fractures is the difficulty in obtaining secure
fixation of an implant to osteoporotic bone.
There is less cortical and cancellous bone
for the screw threads to gain purchase, so
that the pull-out strength of implants is
significantly reduced. Bone mineral density
correlates linearly with the holding power
of screws. The load transmitted at the
bone-implant interface can often exceed
the reduced strain tolerance of osteoporotic
bone. This may result in microfracture,
resorption of the bone, and loosening
of the implant, with secondary failure of
fixation. Consequently, the common mode
of failure of internal fixation in osteoporotic
bone is bone failure rather than implant
breakage. Because of this, the operative
treatment of metaphyseal fractures in the
elderly is associated with an increased rate
of complications; non-union and implant
failure occur in 2% to 10% of fractures,
malunion in 4% to 40% and re-operation
in 3% to 23%.
The general principles of fracture
management in osteoporotic bone require
some changes in surgical technique in
order to decrease the risk of failure at the
bone-implant interface. These include the
use of relative stability techniques such
as intramedullary nails, bone impaction,
buttress fixation, fixed-angle devices, bone
augmentation and joint replacement.
Techniques of internal fixation which aim
to provide absolute stability with lag screws
are usually inappropriate in osteoporotic
bone. Relative stability techniques are the
most efficient at reducing strain at the
bone-implant interface, as the implant is
within the loadbearing axis of the bone.
The treatment of fractures is determined
by three important factors; the soft tissues,
the fracture pattern, and the patient. In the
elderly, each of these factors may present
particular problems. The soft tissues and
skin may be thin because of atrophy or
malnutrition thereby predisposing to
degloving injuries. Arterial disease may
result in ischaemic changes and poor
healing, while venous hypertension
produces oedema, ulcers and chronic
skin changes. Fracture patterns are often
complex because of the altered mechanical
properties of bone, despite the low-energy
nature of the injury. Patient factors are often
complex in the elderly, because the majority
of patients have medical comorbidities
which require careful assessment.
Hall B Session 2
Orthopedic Surgery: Trauma,
Tumor and Complications
295
Treatment of Recalcitrant Long
Bone Non-Unions and Bone Defects:
Application and Clinical Results of
the Diamond Concept
Peter V. Giannoudis MD, Orthopedic Surgery (UK)
Background: Bone defects and long bone
non-unions pose many challenges to the
trauma surgeon. In this study we report
our experience in the treatment of long
bone non-unions and bone defects treated
with the ‘diamond concept’.
Patients and Methods: Between 2008-
2011 patients who were treated in our
institution with bone defect and/or
atrophic long bone non-unions according
to the diamond concept were eligible to
participate. In cases where a long grade
infection was suspected or active infection
was diagnosed, radical debridement and
a two stage procedure with temporarily
stabilisation of the affected limb with
an external fixator was carried out for
eradication of the infection Exclusion
criteria were hypertrophic and pathological
fracture non-unions. Data collected
included demographics, initial fracture
pattern, method of stabilisation, mode of
metal work failure, previous operations,
time to revision of fixation, complications,
time to union, and functional outcome.
For bone defects the ‘induced membrane’
technique was applied. The revision
strategy was based on the ‘diamond
concept’: revision of fixation where
indicated, application of a growth factor
(BMP-7), a scaffold (composite graft (RIA
and orthoss graft)) and concentrated
mesenchymal stem cells harvested from
iliac crest. The minimum follow up was 18
months (12-26).
Results: 30 patients (16 males) met the
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