Venous thromboembolism (VTE) remains an immediate
threat to patients following total hip and knee replacement. While
there is a strong consensus that steps should be taken to minimise
the risk to patients by utilising some forms of prophylaxis for
the vast majority of patients, the methods utilised have been extremely
variable. Clinical practice guidelines (CPGs) have been published
by various professional organisations for over 25 years to provide recommendations
to standardise VTE prophylaxis. Historically, these recommendations
have varied widely depending in underlying assumptions, goals, and
methodology of the various groups. This effort has previously been
exemplified by the American College of Chest Physicians (ACCP) and
the American Academy of Orthopaedic Surgeons (AAOS). The former
group of medical specialists targeted minimising venographically
proven deep vein thrombosis (DVT) (the vast majority of which are
asymptomatic) as their primary goal prior to 2012. The latter group of
surgeons targeted minimising symptomatic VTE. As a result prior
to 2012, the recommendations of the two groups were widely divergent.
In the past year, both groups have reassessed the current literature
with the principal goals of minimising symptomatic VTE events and
bleeding complications. As a result, for the first time the CPGs
of these two major subspecialty organisations are in close agreement.
Since 1996 more than one million metal-on-metal
articulations have been implanted worldwide. Adverse reactions to
metal debris are escalating. Here we present an algorithmic approach
to patient management. The general approach to all arthroplasty
patients returning for follow-up begins with a detailed history,
querying for pain, discomfort or compromise of function. Symptomatic
patients should be evaluated for intra-articular and extra-articular
causes of pain. In large head MoM arthroplasty, aseptic loosening
may be the source of pain and is frequently difficult to diagnose.
Sepsis should be ruled out as a source of pain. Plain radiographs
are evaluated to rule out loosening and osteolysis, and assess component
position. Laboratory evaluation commences with erythrocyte sedimentation
rate and C-reactive protein, which may be elevated. Serum metal
ions should be assessed by an approved facility. Aspiration, with
manual cell count and culture/sensitivity should be performed, with
cloudy to creamy fluid with predominance of monocytes often indicative
of failure. Imaging should include ultrasound or metal artifact
reduction sequence MRI, specifically evaluating for fluid collections
and/or masses about the hip. If adverse reaction to metal debris
is suspected then revision to metal or ceramic-on-polyethylene is indicated
and can be successful. Delay may be associated with extensive soft-tissue
damage and hence poor clinical outcome.
The advent of computer-assisted knee replacement surgery has focused interest on the alignment of the components. However, there is confusion at times between the alignment of the limb as a whole and that of the components. The interaction between them is discussed in this article. Alignment is expressed relative to some reference axis or plane and measurements will vary depending on what is selected as the reference. The validity of different reference axes is discussed. Varying prosthetic alignment has direct implications for surrounding soft-tissue tension. In this context the interaction between alignment and soft-tissue balance is explored and the current knowledge of the relationship between alignment and outcome is summarised.