Previous studies of failure mechanisms leading
to revision total knee replacement (TKR) performed between 1986 and
2000 determined that many failed early, with a disproportionate
amount accounted for by infection and implant-associated factors
including wear, loosening and instability. Since then, efforts have
been made to improve implant performance and instruct surgeons in
best practice. Recently our centre participated in a multi-centre evaluation
of 844 revision TKRs from 2010 to 2011. The purpose was to report
a detailed analysis of failure mechanisms over time and to see if
failure modes have changed over the past 10 to 15 years. Aseptic
loosening was the predominant mechanism of failure (31.2%), followed
by instability (18.7%), infection (16.2%), polyethylene wear (10.0%),
arthrofibrosis (6.9%) and malalignment (6.6%). The mean time to
failure was 5.9 years (ten days to 31 years), 35.3% of all revisions
occurred at less than two years, and 60.2% in the first five years.
With improvements in implant and polyethylene manufacture, polyethylene
wear is no longer a leading cause of failure. Early mechanisms of
failure are primarily technical errors. In addition to improving
implant longevity, industry and surgeons must work together to decrease
these technical errors. All reports on failure of TKR contain patients
with unexplained pain who not infrequently have unmet expectations.
Surgeons must work to achieve realistic patient expectations pre-operatively,
and therefore, improve patient satisfaction post-operatively. Cite this article:
Over the past 30 years there have been many improvements
in implant fixation, correction of deformity, improved polyethylene
wear, and survival after knee replacement. The work over the last
decade has focused on less invasive surgical techniques, multimodal
pain management protocols, more rapid functional recovery and reduced
length of stay, aiming to minimise the side effects of treatment
while maintaining function and implant durability. When combined
and standardised these pre-, intra- and post-operative factors have
now facilitated outpatient knee replacement procedures for unicompartmental
replacement, patella femoral arthroplasty and total knee replacement
(TKR). We have found liposomal bupivacaine, with potential for longer
therapeutic action, to be a helpful adjunct and describe our current
pain management program. The next step in our multimodal program
is to improve the duration of patient satisfaction and reduce cost
and length of stay after TKR. Cite this article:
Direct anterior approaches to the hip have gained
popularity as a minimally invasive method when performing primary
total hip replacement (THR). A retrospective review of a single
institution joint registry was performed in order to compare patient
outcomes after THR using the Anterior Supine Intermuscular (ASI)
approach Cite this article
The common recommended treatment for infected
total hip replacement is two-staged exchange including removal of
all components. However, removal of well-fixed femoral stems can
result in structural bone damage. We recently reported on an alternative
treatment of partial two-stage exchange used in selected cases,
in which a well-fixed femoral stem was left and only the acetabular
component removed, the joint space was debrided thoroughly, an antibiotic-laden
polymethylmethacrylate spacer was moulded using a bulb-type syringe
and placed in the acetabulum, intravenous antibiotics were administered
during the interval, and delayed re-implantation was performed.
In 19 patients treated with this technique from January 2000 to
January 2011, 89% were free of infection at a mean follow-up of
four years (2 to 11). Since then, disposable silicone moulds have
become available to fabricate spacers in separate femoral and head
units. The head spacer mould, which incorporates various neck taper adapter
options, greatly facilitates the technique of partial two-stage
exchange. We report our early experience using disposable silicone
head spacer moulds for partial two-stage exchange in seven patients
with infected primary hip replacements. Cite this article:
Debate has raged over whether a cruciate retaining
(CR) or a posterior stabilised (PS) total knee replacement (TKR) provides
a better range of movement (ROM) for patients. Various sub-sets
of CR design are frequently lumped together when comparing outcomes.
Additionally, multiple factors have been proven to influence the
rate of manipulation under anaesthetic (MUA) following TKR. The
purpose of this study was to determine whether different CR bearing
insert designs provide better ROM or different MUA rates. All primary
TKRs performed by two surgeons between March 2006 and March 2009
were reviewed and 2449 CR-TKRs were identified. The same CR femoral
component, instrumentation, and tibial base plate were consistently
used. In 1334 TKRs a CR tibial insert with 3° posterior slope and
no posterior lip was used (CR-S). In 803 there was an insert with
no slope and a small posterior lip (CR-L) and in 312 knees the posterior
cruciate ligament (PCL) was either resected or lax and a deep-dish,
anterior stabilised insert was used (CR-AS). More CR-AS inserts
were used in patients with less pre-operative ROM and greater pre-operative
tibiofemoral deformity and flexion contracture (p <
0.05). The
mean improvement in ROM was highest for the CR-AS inserts (5.9°
(-40° to 55°) Cite this article:
Metal-on-metal hip arthroplasty gained significant
favor in the first decade of the millennium. However, the past several
years have seen increasing reports of failure, pseudotumor and other
adverse reactions. This study presents the results of a single center’s
15-year experience with metal-on-metal total hip arthroplasty as
strong evidence that metal-on-metal is going, going, gone.
A moderator and panel of five experts led an
interactive session in discussing five challenging and interesting patient
case presentations involving surgery of the hip. The hip pathologies
reviewed included failed open reduction internal fixation of subcapital
femoral neck fracture, bilateral hip disease, evaluation of pain
after metal-on-metal hip arthroplasty, avascular necrosis, aseptic
loosening secondary to osteolysis and polyethylene wear, and management
of ceramic femoral head fracture.
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.