The August 2014 Spine Roundup360 looks at: rhBMP complicates cervical spine surgery; posterior longitudinal ligament revisited; thoracolumbar posterior instrumentation without fusion in burst fractures; risk modelling for VTE events in spinal surgery; the consequences of dural tears in microdiscectomy; trends in revision spinal surgery; radiofrequency denervation likely effective in facet joint pain and hooks optimally biomechanically transition posterior instrumentation.
The August 2014 Wrist &
Hand Roundup360 looks at: Trapeziectomy superior to arthrodesis;
We compared the rate of revision for instability
after total hip replacement (THR) when lipped and non-lipped acetabular
liners were used. We hypothesised that the use of a lipped liner
in a modular uncemented acetabular component reduces the risk of
revision for instability after primary THR. Using data from the
New Zealand Joint Registry, we found that the use of a lipped liner
was associated with a significantly decreased rate of revision for instability
and for all other indications. Adjusting for the size of the femoral
head, the surgical approach and the age and gender of the patient,
this difference remained strongly significant (p <
0.001). We conclude that evidence from the New Zealand registry suggests
that the use of lipped liners with modular uncemented acetabular
components is associated with a decreased rate of revision for instability
after primary THR. Cite this article:
The June 2012 Hip &
Pelvis Roundup360 looks at: whether metal-on-metal is really such a disaster; resurfacings with unexplained pain; large heads and high ion levels; hip arthroscopy for FAI; the inaccuracy of clinical tests for impingement; arthroscopic lengthening of iliopsoas; the OA hip; the injured hamstring – football’s most common injury; an algorithm for hip fracture surgery; and sparing piriformis at THR.
Over recent years hip arthroscopic surgery has
evolved into one of the most rapidly expanding fields in orthopaedic surgery.
Complications are largely transient and incidences between 0.5%
and 6.4% have been reported. However, major complications can and
do occur. This article analyses the reported complications and makes recommendations
based on the literature review and personal experience on how to
minimise them.
Aseptic loosening of the femoral component is
an important indication for revision surgery in unicompartmental knee
replacement (UKR). A new design of femoral component with an additional
peg was introduced for the cemented Oxford UKR to increase its stability.
The purpose of this study was to compare the primary stability of
the two designs of component. Medial Oxford UKR was performed in 12 pairs of human cadaver
knees. In each pair, one knee received the single peg and one received
the twin peg design. Three dimensional micromotion and subsidence
of the component in relation to the bone was measured under cyclical
loading at flexion of 40° and 70° using an optical measuring system.
Wilcoxon matched pairs signed-rank test was performed to detect
differences between the two groups. There was no significant difference in the relative micromotion
(p = 0.791 and 0.380, respectively) and subsidence (p = 0.301 and
0.176, respectively) of the component between the two groups at
both angles of flexion. Both designs of component offered good strength
of fixation in this cadaver study. Cite this article:
Periprosthetic fractures are an increasingly
common complication following joint replacement. The principles
which underpin their evaluation and treatment are common across
the musculoskeletal system. The Unified Classification System proposes
a rational approach to treatment, regardless of the bone that is
broken or the joint involved. Cite this article:
Following the recall of modular neck hip stems
in July 2012, research into femoral modularity will intensify over
the next few years. This review aims to provide surgeons with an
up-to-date summary of the clinically relevant evidence. The development
of femoral modularity, and a classification system, is described.
The theoretical rationale for modularity is summarised and the clinical
outcomes are explored. The review also examines the clinically relevant problems
reported following the use of femoral stems with a modular neck. Joint replacement registries in the United Kingdom and Australia
have provided data on the failure rates of modular devices but cannot
identify the mechanism of failure. This information is needed to
determine whether modular neck femoral stems will be used in the
future, and how we should monitor patients who already have them implanted. Cite this article:
Deficiency of the abductor mechanism is a well-recognised
cause of pain and limping after total hip replacement (THR). This
can be found incidentally at the time of surgery, or it may arise
as a result of damage to the superior gluteal nerve intra-operatively,
or after surgery owing to mechanical failure of the abductor muscle
repair or its detachment from the greater trochanter. The incidence
of abductor failure has been reported as high as 20% in some studies.
The management of this condition remains a dilemma for the treating
surgeon. We review the current state of knowledge concerning post-THR
abductor deficiency, including the aetiology, diagnosis and management,
and the outcomes of surgery for this condition. Cite this article:
Nanotechnology is the study, production and controlled
manipulation of materials with a grain size <
100 nm. At this
level, the laws of classical mechanics fall away and those of quantum
mechanics take over, resulting in unique behaviour of matter in
terms of melting point, conductivity and reactivity. Additionally,
and likely more significant, as grain size decreases, the ratio
of surface area to volume drastically increases, allowing for greater interaction
between implants and the surrounding cellular environment. This
favourable increase in surface area plays an important role in mesenchymal
cell differentiation and ultimately bone–implant interactions. Basic science and translational research have revealed important
potential applications for nanotechnology in orthopaedic surgery,
particularly with regard to improving the interaction between implants
and host bone. Nanophase materials more closely match the architecture
of native trabecular bone, thereby greatly improving the osseo-integration
of orthopaedic implants. Nanophase-coated prostheses can also reduce
bacterial adhesion more than conventionally surfaced prostheses.
Nanophase selenium has shown great promise when used for tumour
reconstructions, as has nanophase silver in the management of traumatic
wounds. Nanophase silver may significantly improve healing of peripheral
nerve injuries, and nanophase gold has powerful anti-inflammatory
effects on tendon inflammation. Considerable advances must be made in our understanding of the
potential health risks of production, implantation and wear patterns
of nanophase devices before they are approved for clinical use.
Their potential, however, is considerable, and is likely to benefit
us all in the future. Cite this article:
The April 2014 Oncology Roundup360 looks at: Eyeball as good as microscope for tumour margins; when is best to stabilise femoral metastases?; fluorine does not cause bone tumours; whether giant cell tumour of the proximal femur ever successfully managed; extraskeletal osteosarcoma; modular lower limb tumour reconstruction; and observational studies the basis for most bone tumour treatment.
We report a case of a male patient presenting
with bilateral painful but apparently well-positioned and -fixed
large-diameter metal-on-metal hip replacements four years post-operatively.
Multiple imaging modes revealed a thick-walled, cystic expansile
mass in communication with the hip joint (a pseudotumour). Implant
retrieval analysis and tissue culture eliminated high bearing wear
or infection as causes for the soft-tissue reaction, but noted marked corrosion
of the modular neck taper adaptor and corrosion products in the
tissues. Therefore, we believe corrosion products from the taper
caused by mismatch of the implant components led to pseudotumour
formation requiring revision.
We investigated the incidence of and risk factors
for venous thromboembolism (VTE) following surgery of the shoulder
and elbow and assessed the role of thromboprophylaxis in upper limb
surgery. All papers describing VTE after shoulder and elbow surgery
published in the English language literature before 31 March 2012
were reviewed. A total of 14 papers were available for analysis,
most of which were retrospective studies and case series. The incidence
of VTE was 0.038% from 92 440 shoulder arthroscopic procedures,
0.52% from 42 261 shoulder replacements, and 0.64% from 4833 procedures
for fractures of the proximal humerus (open reduction and internal fixation
or hemiarthroplasty). The incidence following replacement of the
elbow was 0.26% from 2701 procedures. Diabetes mellitus, rheumatoid
arthritis and ischaemic heart disease were identified as the major
risk factors. The evidence that exists on thromboprophylaxis is based on level
III and IV studies, and we therefore cannot make any recommendations
on prophylaxis based on the current evidence. It seems reasonable
to adopt a multimodal approach that involves all patients receiving
mechanical prophylaxis, with chemical prophylaxis reserved for those
who are at high risk for VTE. Cite this article:
Intravenous tranexamic acid (TXA) has been shown
to be effective in reducing blood loss and the need for transfusion
after joint replacement. Recently, there has been interest in applying
it topically before the closure of surgical wounds. This has the
advantages of ease of application, maximum concentration at the
site of bleeding, minimising its systemic absorption and, consequently,
concerns about possible side-effects. We conducted a systematic review and meta-analysis which included
14 randomised controlled trials (11 in knee replacement, two in
hip replacement and one in both) which investigated the effect of
topical TXA on blood loss and rates of transfusion. Topical TXA
significantly reduced the rate of blood transfusion (total knee
replacement: risk ratio (RR) 4.51; 95% confidence interval (CI):
3.02 to 6.72; p <
0.001 (nine trials, I2 = 0%); total
hip replacement: RR 2.56; 95% CI: 1.32 to 4.97, p = 0.004 (one trial)).
The rate of thromboembolic events with topical TXA were similar
to those found with a placebo. Indirect comparison of placebo-controlled
trials of topical and intravenous TXA indicates that topical administration
is superior to the intravenous route. In conclusion, topical TXA is an effective and safe method of
reducing the need for blood transfusion after total knee and hip
replacement. Further research is required to find its optimum dose
for topical use. Cite this article:
We compared a new fixation system, the Targon
Femoral Neck (TFN) hip screw, with the current standard treatment of
cannulated screw fixation. This was a single-centre, participant-blinded,
randomised controlled trial. Patients aged 65 years and over with
either a displaced or undisplaced intracapsular fracture of the
hip were eligible. The primary outcome was the risk of revision
surgery within one year of fixation. A total of 174 participants were included in the trial. The absolute
reduction in risk of revision was of 4.7% (95% CI 14.2 to 22.5)
in favour of the TFN hip screw (chi-squared test, p = 0.741), which
was less than the pre-specified level of minimum clinically important
difference. There were no significant differences in any of the
secondary outcome measures. We found no evidence of a clinical difference in the risk of
revision surgery between the TFN hip screw and cannulated screw
fixation for patients with an intracapsular fracture of the hip. Cite this article:
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 April 2014 Knee Roundup360 looks at: mobile compression as good as chemical thromboprophylaxis; patellar injury with MIS knee surgery; tibial plateau fracture results not as good as we thought; back and knee pain; metaphyseal sleeves may be the answer in revision knee replacement; oral tranexamic acid; gentamycin alone in antibiotic spacers; and whether the jury is still out on unloader braces.