Cost is a factor in the choice of prosthetic components in joint replacement. For a given performance, the least expensive components are the most cost-effective. When evaluating a new prosthesis with an unknown outcome, the use of an economic model allows estimation of potential cost-effectiveness. We used published data for the survival of cemented total hip replacements from Sweden, and cost and demographic information from New South Wales, Australia, in such a model. In young active total hip recipients a new prosthetic design which offered a 90% improvement in survivorship over 15 years and a 15% reduction in the cost of
The primary aim of this study was to determine the surgical team’s
learning curve for introducing robotic-arm assisted unicompartmental
knee arthroplasty (UKA) into routine surgical practice. The secondary
objective was to compare accuracy of implant positioning in conventional
jig-based UKA versus robotic-arm assisted UKA. This prospective single-surgeon cohort study included 60 consecutive
conventional jig-based UKAs compared with 60 consecutive robotic-arm
assisted UKAs for medial compartment knee osteoarthritis. Patients
undergoing conventional UKA and robotic-arm assisted UKA were well-matched
for baseline characteristics including a mean age of 65.5 years
(Aims
Patients and Methods
The aim of this study was to examine the results of the acetabular
distraction technique in achieving implantation of a stable construct,
obtaining biological fixation, and producing healing of chronic
pelvic discontinuity at revision total hip arthroplasty. We identified 32 patients treated between 2006 and 2013 who underwent
acetabular revision for a chronic pelvic discontinuity using acetabular
distraction, and who were radiographically evaluated at a mean of
62 months (25 to 160). Of these patients, 28 (87.5%) were female.
The mean age at the time of revision was 67 years (44 to 86). The patients
represented a continuous series drawn from two institutions that
adhered to an identical operative technique.Aims
Patients and Methods
The aim of this study was to compare the rate of perioperative
complications following aseptic revision total hip arthroplasty
(THA) in patients aged ≥ 80 years with that in those aged <
80
years, and to identify risk factors for the incidence of serious
adverse events in those aged ≥ 80 years using a large validated
national database. Patients who underwent aseptic revision THA were identified in
the 2005 to 2015 National Surgical Quality Improvement Program (NSQIP)
database and stratified into two age groups: those aged <
80
years and those aged ≥ 80 years. Preoperative and procedural characteristics
were compared. Multivariate regression analysis was used to compare
the risk of postoperative complications and readmission. Risk factors
for the development of a serious adverse event in those aged ≥ 80
years were characterized.Aims
Patients and Methods
This study compared multiple sclerosis (MS) patients who underwent
primary total hip arthroplasty (THA) with a matched cohort. Specifically,
we evaluated: 1) implant survivorship; 2) functional outcomes (modified
Harris Hip Scores (mHHS), Hip Disability and Osteoarthritis Outcome
Score, Joint Replacement (HOOS JR), and modified Multiple Sclerosis
Impact Scale (mMSIS) scores (with the MS cohort also evaluated based
on the disease phenotype)); 3) physical therapy duration and return
to function; 4) radiographic outcomes; and 5) complications. We reviewed our institution’s database to identify MS patients
who underwent THA between January 2008 and June 2016. A total of
34 MS patients (41 hips) were matched in a 1:2 ratio to a cohort
of THA patients who did not have MS, based on age, body mass index
(BMI), and Charlson/Deyo score. Patient records were reviewed for complications,
and their functional outcomes and radiographs were reviewed at their
most recent follow-up.Aims
Patients and Methods
The advent of trabecular metal (TM) augments has revolutionized
the management of severe bone defects during acetabular reconstruction.
The purpose of this study was to evaluate patients undergoing revision
total hip arthroplasty (THA) with the use of TM augments for reconstruction
of Paprosky IIIA and IIIB defects. A retrospective study was conducted at four centres between August
2008 and January 2015. Patients treated with TM augments and TM
shell for a Paprosky grade IIIA or IIIB defect, in the absence of
pelvic discontinuity, and who underwent revision hip arthroplasty
with the use of TM augments were included in the study. A total
of 41 patients with minimum follow-up of two years were included
and evaluated using intention-to-treat analysis.Aims
Patients and Methods
The primary aim of this study was to evaluate the performance
and safety of magnetically controlled growth rods in the treatment
of early onset scoliosis. Secondary aims were to evaluate the clinical
outcome, the rate of further surgery, the rate of complications,
and the durability of correction. We undertook an observational prospective cohort study of children
with early onset scoliosis, who were recruited over a one-year period
and followed up for a minimum of two years. Magnetically controlled
rods were introduced in a standardized manner with distractions
performed three-monthly thereafter. Adverse events which were both related
and unrelated to the device were recorded. Ten children, for whom
relevant key data points (such as demographic information, growth
parameters, Cobb angles, and functional outcomes) were available,
were recruited and followed up over the period of the study. There
were five boys and five girls. Their mean age was 6.2 years (2.5
to 10).Aims
Patients and Methods
The aim of this study was to determine whether there is a difference
in the rate of wear between acetabular components positioned within
and outside the ‘safe zones’ of anteversion and inclination angle. We reviewed 100 hips in 94 patients who had undergone primary
total hip arthroplasty (THA) at least ten years previously. Patients
all had the same type of acetabular component with a bearing couple
which consisted of a 28Â mm cobalt-chromium head on a highly crosslinked
polyethylene (HXLPE) liner. A supine radiostereometric analysis
(RSA) examination was carried out which acquired anteroposterior
(AP) and lateral paired images. Acetabular component anteversion
and inclination angles were measured as well as total femoral head
penetration, which was divided by the length of implantation to
determine the rate of polyethylene wear.Aims
Patients and Methods
The use of impacted, morsellised bone grafts has become popular in revision total hip arthroplasty (THA). The initial stability of the reconstruction and the effectiveness of any subsequent process of revitalisation and incorporation will depend on the mechanical integrity of the graft. Our aim in this study was to document the time-dependent mechanical properties of the morsellised graft. This information is useful in clinical application of the graft, in studies of migration of the implant and in the design of the joint. We used 16 specimens of impacted, morsellised cancellous bone from the sternum of goats to assess the mechanical properties by confined compression creep tests. Consideration of the graft material as a porous, permeable solid, filled with fluid, allowed determination of the compressive modulus of the matrix, and its permeability to fluid flow. In all specimens the compression tests showed large, irreversible deformations, caused by flow-independent creep behaviour as a result of rolling and sliding of the bone chips. The mean permeability was 8.82 *10. −12. m. 4. /Ns (SD 43%), and the compressive modulus was 38.7 MPa (SD 34%). No correlation was found between the apparent density and the permeability or between the apparent density and the compressive modulus. The irreversible deformations in the graft could be captured by a creep law, for which the parameters were quantified. We conclude that in clinical use the graft is bound to be subject to permanent deformation after operation. The permeability of the material is relatively high compared with, for example, human cartilage. The confined compression modulus is relatively low compared with cancellous bone of the same apparent density. Designs of prostheses used in
This study aimed to compare the change in health-related quality
of life of patients receiving a traditional cemented monoblock Thompson
hemiarthroplasty compared with a modern cemented modular polished-taper
stemmed hemiarthroplasty for displaced intracapsular hip fractures. This was a pragmatic, multicentre, multisurgeon, two-arm, parallel
group, randomized standard-of-care controlled trial. It was embedded
within the WHiTE Comprehensive Cohort Study. The sample size was
964 patients. The setting was five National Health Service Trauma
Hospitals in England. A total of 964 patients over 60 years of age who
required hemiarthroplasty of the hip between February 2015 and March
2016 were included. A standardized measure of health outcome, the
EuroQol (EQ-5D-5L) questionnaire, was carried out on admission and
at four months following the operation.Aims
Patients and Methods
The primary aim of this retrospective study was to identify the
incidence of heterotopic ossification (HO) following elective and
trauma elbow arthroplasty. The secondary aim was to determine clinical
outcomes with respect to the formation of heterotopic ossification. A total of 55 total elbow arthroplasties (TEAs) (52 patients)
performed between June 2007 and December 2015 were eligible for
inclusion in the study (29 TEAs for primary elective arthroplasty
and 26 TEAs for trauma). At review, 15 patients (17 total elbow
arthroplasties) had died from unrelated causes. There were 14 men
and 38 women with a mean age of 70 years (42 to 90). The median
clinical follow-up was 3.6 years (1.2 to 6) and the median radiological follow-up
was 3.1 years (0.5 to 7.5).Aim
Patients and Methods
The reasons for failure of a hemirthroplasty (HA) when used to
treat a proximal humeral fracture include displaced or necrotic
tuberosities, insufficient metaphyseal bone-stock, and rotator cuff
tears. Reverse total shoulder arthroplasty (rTSA) is often the only
remaining form of treatment in these patients. The aim of this study
was to evaluate the clinical outcome after conversions from a failed
HA to rTSA. A total of 35 patients, in whom a HA, as treatment for a fracture
of the proximal humerus, had failed, underwent conversion to a rTSA.
A total of 28 were available for follow-up at a mean of 61 months
(37 to 91), having been initially reviewed at a mean of 20 months
(12 to 36) postoperatively. Having a convertible design, the humeral
stem could be preserved in nine patients. The stem was removed in
the other 19 patients and a conventional rTSA was implanted. At
final follow-up, patients were assessed using the American Shoulder
and Elbow Surgeons (ASES) score, the Constant Score, and plain radiographs.Aims
Material and Methods
Plating displaced proximal humeral fractures is associated with a high rate of screw perforation. Dynamization of the proximal screws might prevent these complications. The aim of this study was to develop and evaluate a new gliding screw concept for plating proximal humeral fractures biomechanically. Eight pairs of three-part humeral fractures were randomly assigned for pairwise instrumentation using either a prototype gliding plate or a standard PHILOS plate, and four pairs were fixed using the gliding plate with bone cement augmentation of its proximal screws. The specimens were cyclically tested under progressively increasing loading until perforation of a screw. Telescoping of a screw, varus tilting and screw migration were recorded using optical motion tracking.Aims
Methods
