The aim of this study was to evaluate the long-term inducible
displacement of cemented tibial components ten years after total
knee arthroplasty (TKA). A total of 15 patients from a previously reported prospective
trial of fixation using radiostereometric analysis (RSA) were examined
at a mean of 11 years (10 to 11) postoperatively. Longitudinal supine
RSA examinations were acquired at one week, one year, and two years
postoperatively and at final follow-up. Weight-bearing RSA examinations
were also undertaken with the operated lower limb in neutral and
in maximum internal rotation positions. Maximum total point motion
(MTPM) was calculated for the longitudinal and inducible displacement examinations
(supine Aims
Patients and Methods
Enhanced micromotions between the implant and surrounding bone can impair osseointegration, resulting in fibrous encapsulation and aseptic loosening of the implant. Since the effect of micromotions on human bone cells is sparsely investigated, an Micromotions ranging from 25 µm to 100 µm were applied as sine or triangle signal with 1 Hz frequency to human osteoblasts seeded on collagen scaffolds. Micromotions were applied for six hours per day over three days. During the micromotions, a static pressure of 527 Pa was exerted on the cells by Ti6Al4V cylinders. Osteoblasts loaded with Ti6Al4V cylinders and unloaded osteoblasts without micromotions served as controls. Subsequently, cell viability, expression of the osteogenic markers collagen type I, alkaline phosphatase, and osteocalcin, as well as gene expression of osteoprotegerin, receptor activator of NF-κB ligand, matrix metalloproteinase-1, and tissue inhibitor of metalloproteinase-1, were investigated.Objectives
Methods
Post-operative migration of cemented acetabular components as
measured by radiostereometric analysis (RSA) has a strong predictive
power for late, aseptic loosening. Also, radiolucent lines predict
late loosening. Migration has been reduced by systemic bisphosphonate
treatment in randomised trials of hip and knee arthroplasty. Used
as a local treatment, a higher local dose of bisphosphonate can
be achieved without systemic exposure. We wished to see if this
principle could be applied usefully in total hip arthroplasty (THA). In this randomised placebo-controlled, double-blinded trial with
60 participants, we compressed gauze soaked in bisphosphonate solution
(ibandronate) or saline against the acetabular bone bed immediately
before cementing the acetabular component. RSA, classification of
radiolucent lines, the Harris Hip Score (HHS) and the Western Ontario McMasters
Universities Osteoarthritis Index (WOMAC) were carried out at three-,
six-, 12-, and 24-month follow-up.Aims
Patients and Methods
Secondary fracture healing is strongly influenced by the stiffness of the bone-fixator system. Biomechanical tests are extensively used to investigate stiffness and strength of fixation devices. The stiffness values reported in the literature for locked plating, however, vary by three orders of magnitude. The aim of this study was to examine the influence that the method of restraint and load application has on the stiffness produced, the strain distribution within the bone, and the stresses in the implant for locking plate constructs. Synthetic composite bones were used to evaluate experimentally the influence of four different methods of loading and restraining specimens, all used in recent previous studies. Two plate types and three screw arrangements were also evaluated for each loading scenario. Computational models were also developed and validated using the experimental tests.Objectives
Methods
The aims of this study were to describe the prevalence of previous
lumbar surgery in patients who undergo total hip arthroplasty (THA)
and to investigate their patient-reported outcomes (PROMs) one year
post-operatively. Data from the Swedish Hip Arthroplasty Register and the Swedish
Spine Register gathered from 2002 to 2013 were merged to identify
a group of patients who had undergone lumbar surgery before THA
(n = 997) and a carefully matched one-to-one control group. We investigated
differences in the one-year post-operative PROMs between the groups.
Linear regression analyses were used to explore the associations
between previous lumbar surgery and these PROMs following THA. The
prevalence of prior lumbar surgery was calculated as the ratio of
patients identified with previous lumbar surgery between 2002 and
2012, and divided by the total number of patients who underwent
a THA in 2012.Aims
Patients and Methods
Few studies have assessed outcomes following non-metal-on-metal hip arthroplasty (non-MoMHA) revision surgery performed for adverse reactions to metal debris (ARMD). We assessed outcomes following non-MoMHA revision surgery performed for ARMD, and identified predictors of re-revision. We performed a retrospective observational study using data from the National Joint Registry for England and Wales. All non-MoMHAs undergoing revision surgery for ARMD between 2008 and 2014 were included (185 hips in 185 patients). Outcome measures following ARMD revision were intra-operative complications, mortality and re-revision surgery. Predictors of re-revision were identified using Cox regression.Objectives
Methods
Static radiostereometric analysis (RSA) using implanted markers is considered the most accurate system for the evaluation of prosthesis migration. By using CT bone models instead of markers, combined with a dynamic RSA system, a non-invasive measurement of joint movement is enabled. This method is more accurate than current 3D skin marker-based tracking systems. The purpose of this study was to evaluate the accuracy of the CT model method for measuring knee joint kinematics in static and dynamic RSA using the marker method as the benchmark. Bone models were created from CT scans, and tantalum beads were implanted into the tibia and femur of eight human cadaver knees. Each specimen was secured in a fixture, static and dynamic stereoradiographs were recorded, and the bone models and marker models were fitted to the stereoradiographs.Objectives
Methods
Advocates of debridement, antibiotics and implant retention (DAIR)
in hip periprosthetic joint infection (PJI) argue that a procedure
not disturbing a sound prosthesis-bone interface is likely to lead
to better survival and functional outcome compared with revision.
This case-control study aims were to compare outcome of DAIRs for
infected primary total hip arthroplasty (THA) with outcomes following
primary THA and two-stage revision of infected primary THAs. We retrospectively reviewed all DAIRs, performed for confirmed
infected primary hip arthropasty (n = 82) at out institution, between
1997 and 2013. Data recorded included full patient information and
type of surgery. Outcome measures included complications, mortality,
implant survivorship and functional outcome. Outcome was compared with
two control groups matched for gender and age; a cohort of primary
THAs (n = 120) and a cohort of two-stage revisions for infection
(n = 66).Aims
Patients and Methods
Nerve palsy is a well-described complication
following total hip arthroplasty, but is highly distressing and
disabling. A nerve palsy may cause difficulty with the post-operative
rehabilitation, and overall mobility of the patient. Nerve palsy
may result from compression and tension to the affected nerve(s)
during the course of the operation via surgical manipulation and
retractor placement, tension from limb lengthening or compression
from post-operative hematoma. In the literature, hip dysplasia,
lengthening of the leg, the use of an uncemented femoral component, and
female gender are associated with a greater risk of nerve palsy.
We examined our experience at a high-volume, tertiary care referral
centre, and found an overall incidence of 0.3% out of 39 056 primary
hip arthroplasties. Risk factors found to be associated with the
incidence of nerve palsy at our institution included the presence
of spinal stenosis or lumbar disc disease, age younger than 50,
and smoking. If a nerve palsy is diagnosed, imaging is mandatory
and surgical evacuation or compressive haematomas may be beneficial.
As palsies are slow to recover, supportive care such as bracing,
therapy, and reassurance are the mainstays of treatment. Cite this article:
Aims. The purpose of the present study was to examine the long-term
fixation of a cemented fixed-bearing polished titanium tibial baseplate
(Genesis ll). . Patients and Methods. Patients enrolled in a previous two-year prospective trial (n
= 35) were recalled at ten years. Available patients (n = 15) underwent
radiostereometric analysis (RSA) imaging in a supine position using
a conventional RSA protocol. Migration of the tibial component in
all planes was compared between initial and ten-year follow-up.
Outcome scores including the Knee Society Score, Western Ontario
and McMaster Universities Arthritis Index, 12-item Short Form Health
Survey, Forgotten Joint Score, and University of California, Los
Angeles Activity Score were recorded. Results. At ten years, the mean migration of the tibial component was
less than 0.1 mm and 0.1° in all planes relative to the post-operative
RSA exam. Maximum total point movement increased with time (p =
0.002) from 0.23 mm (. sd. 0.18) at six weeks to 0.42 mm (. sd. 0.20)
at ten years. Conclusion. The low level of tibial baseplate migration found in the present
study correlates to the low rate of revision for this implant as
reported in individual studies and in joint replacement registries. Take home message: Overall, the implant was found to be well
fixed at ten years, supporting its continued clinical use and the
predictive power of RSA for determining long-term
Using a systematic review, we investigated whether there is an
increased risk of post-operative infection in patients who have
received an intra-articular corticosteroid injection to the hip
for osteoarthritis prior to total hip arthroplasty (THA). Studies dealing with an intra-articular corticosteroid injection
to the hip and infection following subsequent THA were identified
from databases for the period between 1990 to 2013. Retrieved articles
were independently assessed for their methodological quality.Aims
Methods
To assess the extent of osteointegration in two designs of shoulder
resurfacing implants. Bony integration to the Copeland cylindrical
central stem design and the Epoca RH conical-crown design were compared. Implants retrieved from six patients in each group were pair-matched.
Mean time to revision surgery of Copeland implants was 37 months
(standard deviation (Aims
Patients and Methods
Tapered fluted titanium stems are increasingly
used for femoral revision arthroplasty. They are available in modular and
non-modular forms. Modularity has advantages when the bone loss
is severe, the proximal femur is mis shapen or the surgeon is unfamiliar
with the implant, but it introduces the risk of fracture of the
stem at the junction between it and the proximal body segment. For
that reason, and while awaiting intermediate-term results of more recently
introduced designs of this junction, non-modularity has attracted
attention, at least for straightforward revision cases. We review the risks and causes of fracture of tapered titanium
modular revision stems and present an argument in favour of the
more selective use of modular designs. Cite this article:
The custom triflange is a patient-specific implant
for the treatment of severe bone loss in revision total hip arthroplasty
(THA). Through a process of three-dimensional modelling and prototyping,
a hydroxyapatite-coated component is created for acetabular reconstruction.
There are seven level IV studies describing the clinical results
of triflange components. The most common complications include dislocation
and infection, although the rates of implant removal are low. Clinical
results are promising given the challenging problem. We describe
the design, manufacture and implantation process and review the
clinical results, contrasting them to other methods of acetabular
reconstruction in revision THA. Cite this article:
The primary purpose of this study of metal-on-metal
(MoM) hip resurfacing was to compare the effect of using a cementless
or cemented femoral component on the subsequent bone mineral density
(BMD) of the femoral neck. This was a single-centre, prospective, double-blinded control
trial which randomised 120 patients (105 men and 15 women) with
a mean age of 49.4 years (21 to 68) to receive either a cemented
or cementless femoral component. Follow-up was to two years. Outcome
measures included total and six-point region-of-interest BMD of
the femoral neck, radiological measurements of acetabular inclination,
neck-shaft and stem-shaft angles, and functional outcome scores
including the Harris hip score, the Western Ontario and McMaster
Universities Osteoarthritis Index and the University of California
at Los Angeles activity scale. In total, 17 patients were lost to follow-up leaving 103 patients
at two years. There were no revisions in the cementless group and
three revisions (5%) in the cemented group (two because of hip pain
and one for pseudotumour). The total BMD was significantly higher in the cementless group
at six months (p <
0.001) and one year (p = 0.01) than in the
cemented group, although there was a loss of statistical significance
in the difference at two years (p = 0.155). All patient outcomes improved significantly: there were no significant
differences between the two groups. The results show better preservation of femoral neck BMD with
a cementless femoral component after two years of follow-up. Further
investigation is needed to establish whether this translates into
improved survivorship. Cite this article:
Revision knee arthroplasty presents a number
of challenges, not least of which is obtaining solid primary fixation
of implants into host bone. Three anatomical zones exist within
both femur and tibia which can be used to support revision implants.
These consist of the joint surface or epiphysis, the metaphysis
and the diaphysis. The methods by which fixation in each zone can
be obtained are discussed. The authors suggest that solid fixation
should be obtained in at least two of the three zones and emphasise
the importance of pre-operative planning and implant selection. Cite this article:
