The aims of this study were to determine the indications and
frequency of ordering a CT pulmonary angiography (CTPA) following
primary arthroplasty of the hip and knee, and to determine the number
of positive scans in these patients, the location of emboli and
the outcome for patients undergoing CTPA. We analyzed the use of CTPA, as an inpatient and up to 90 days
as an outpatient, in a cohort of patients and reviewed the medical
records and imaging for each patient undergoing CTPA.Aims
Patients and Methods
Tranexamic acid (TXA) is proven to reduce blood loss following total knee arthroplasty (TKA), but there are limited data on the impact of similar dosing regimens in revision TKA. The purpose of this multicentre randomized clinical trial was to determine the optimal regimen to maximize the blood-sparing properties of TXA in revision TKA. From six-centres, 233 revision TKAs were randomized to one of four regimens: 1 g of intravenous (IV) TXA given prior to the skin incision, a double-dose regimen of 1 g IV TXA given both prior to skin incision and at time of wound closure, a combination of 1 g IV TXA given prior to skin incision and 1 g of intraoperative topical TXA, or three doses of 1950 mg oral TXA given two hours preoperatively, six hours postoperatively, and on the morning of postoperative day one. Randomization was performed based on the type of revision procedure to ensure equivalent distribution among groups. Power analysis determined that 40 patients per group were necessary to identify a 1 g/dl difference in the reduction of haemoglobin postoperatively between groups with an alpha of 0.05 and power of 0.80. Per-protocol analysis involved regression analysis and two one-sided Aims
Patients and Methods
While medial unicompartmental knee arthroplasty (UKA) is indicated
for patients with full-thickness cartilage loss, it is occasionally
used to treat those with partial-thickness loss. The aim of this
study was to investigate the five-year outcomes in a consecutive
series of UKAs used in patients with partial thickness cartilage
loss in the medial compartment of the knee. Between 2002 and 2014, 94 consecutive UKAs were undertaken in
90 patients with partial thickness cartilage loss and followed up
independently for a mean of six years (1 to 13). These patients
had partial thickness cartilage loss either on both femur and tibia
(13 knees), or on either the femur or the tibia, with full thickness
loss on the other surface of the joint (18 and 63 knees respectively).
Using propensity score analysis, these patients were matched 1:2 based
on age, gender and pre-operative Oxford Knee Score (OKS) with knees
with full thickness loss on both the femur and tibia. The functional
outcomes, implant survival and incidence of re-operations were assessed
at one, two and five years post-operatively. A subgroup of 36 knees
in 36 patients with partial thickness cartilage loss, who had pre-operative
MRI scans, was assessed to identify whether there were any factors
identified on MRI that predicted the outcome.Aims
Patients and Methods
Up to 40% of unicompartmental knee arthroplasty (UKA) revisions are performed for unexplained pain which may be caused by elevated proximal tibial bone strain. This study investigates the effect of tibial component metal backing and polyethylene thickness on bone strain in a cemented fixed-bearing medial UKA using a finite element model (FEM) validated experimentally by digital image correlation (DIC) and acoustic emission (AE). A total of ten composite tibias implanted with all-polyethylene (AP) and metal-backed (MB) tibial components were loaded to 2500 N. Cortical strain was measured using DIC and cancellous microdamage using AE. FEMs were created and validated and polyethylene thickness varied from 6 mm to 10 mm. The volume of cancellous bone exposed to < -3000 µε (pathological loading) and < -7000 µε (yield point) minimum principal (compressive) microstrain and > 3000 µε and > 7000 µε maximum principal (tensile) microstrain was computed.Objectives
Materials and Methods
The primary aim of this independent prospective randomised trial
was to compare serum metal ion levels for ceramic-on-metal (CoM)
and metal-on-metal (MoM) bearing surfaces in total hip arthroplasty
(THA). Our one-year results demonstrated elevation in metal ion
levels above baseline with no significant difference between the
CoM and MoM groups. This paper reviews the five-year data. The implants used in each patient differed only in respect to
the type of femoral head (ceramic or metal). At five-year follow-up
of the 83 enrolled patients, data from 67 (36 CoM, 31 MoM) was available
for comparison.Aims
Patients and Methods
Total knee arthroplasty (TKA) is a cost effective
and extremely successful operation. As longevity increases, the demand
for primary TKA will continue to rise. The success and survivorship
of TKAs are dependent on the demographics of the patient, surgical
technique and implant-related factors. Currently the risk of failure of a TKA requiring revision surgery
ten years post-operatively is 5%. The most common indications for revision include aseptic loosening
(29.8%), infection (14.8%), and pain (9.5%). Revision surgery poses
considerable clinical burdens on patients and financial burdens
on healthcare systems. We present a current concepts review on the epidemiology of failed
TKAs using data from worldwide National Joint Registries. Cite this article:
This study reports on the first 150 consecutive
Oxford cementless unicompartmental knee arthroplasties (UKA) performed
in an independent centre (126 patients). All eligible patients had
functional scores (Oxford knee score and high activity arthroplasty
score) recorded pre-operatively and at two- and five-years of follow-up. Fluoroscopically
aligned radiographs were taken at five years and analysed for any
evidence of radiolucent lines (RLLs), subsidence or loosening. The
mean age of the cohort was 63.6 years (39 to 86) with 81 (53.1%)
males. Excellent functional scores were maintained at five years
and there were no progressive RLLs demonstrated on radiographs.
Two patients underwent revision to a total knee arthroplasty giving
a revision rate of 0.23/100 (95% confidence interval 0.03 to 0.84)
component years with overall component survivorship of 98.7% at
five years. There were a further four patients who underwent further
surgery on the same knee, two underwent bearing exchanges for dislocation
and two underwent lateral UKAs for disease progression. This was
a marked improvement from other UKAs reported in New Zealand Joint
Registry data and supports the designing centre’s early results. Cite this article:
The use of robotics in arthroplasty surgery is expanding rapidly as improvements in the technology evolve. This article examines current evidence to justify the usage of robotics, as well as the future potential in this emerging field.
The June 2015 Knee Roundup360 looks at: Cruciate substituting
Because there have been no standard methods to determine pre-operatively
the thickness of resection of the proximal tibia in unicompartmental
knee arthroplasty (UKA), information about the relationship between
the change of limb alignment and the joint line elevation would
be useful for pre-operative planning. The purpose of this study
was to clarify the correlation between the change of limb alignment
and the change of joint line height at the medial compartment after
UKA. A consecutive series of 42 medial UKAs was reviewed retrospectively.
These patients were assessed radiographically both pre- and post-operatively
with standing anteroposterior radiographs. The thickness of bone
resection at the proximal tibia and the distal femur was measured
radiographically. The relationship between the change of femorotibial
angle (δFTA) and the change of joint line height, was analysed.Objectives
Methods
