Primary (or spontaneous) and secondary osteonecrosis of the knee
can lead to severe joint degeneration, for which either total or
unicompartmental arthroplasty may be considered. However, there
are limited studies analyzing outcomes of unicompartmental knee arthroplasties
(UKAs) for osteonecrosis involving an isolated compartment of the
knee. The aims of this study were to analyze outcomes of UKAs for
osteonecrosis with specific focus on 1) survivorship free of any
revision or reoperation, 2) risk factors for failure, 3) clinical outcomes,
and 4) complications. A total of 45 patients underwent 46 UKAs for knee osteonecrosis
between 2002 and 2014 at our institution (The Mayo Clinic, Rochester,
Minnesota). Twenty patients (44%) were female; the mean age of the
patients was 66 years, and mean body mass index (BMI) was 31 kg/m2. Of
the 46 UKAs, 44 (96%) were medial UKAs, and 35 (76%) were fixed-bearing
design. Mean mechanical axis postoperatively was 1.5° varus (0°
to 5° varus); 41 UKAs (89%) were performed for primary osteonecrosis.
Mean follow-up was five years (2 to 12)Aims
Patients and Methods
To determine whether there is any association between glomerular
filtration rate (GFR) and blood cobalt (Co) and chromium (Cr) levels
in patients with metal-on-metal (MoM) hip arthroplasty. We identified 179 patients with a unilateral 36 mm diameter head
as part of a stemmed Summit-Pinnacle MoM hip arthroplasty. GFR was
calculated using the Modification of Diet in Renal Disease formula.Aims
Patients and Methods
Loss or absence of proximal femoral bone in revision total hip
arthroplasty (THA) remains a significant challenge. While the main
indication for the use of proximal femoral replacements (PFRs) is
in the treatment of malignant disease, they have a valuable role
in revision THA for loosening, fracture and infection in patients
with bone loss. Our aim was to determine the clinical outcomes,
implant survivorship, and complications of PFRs used in revision
THA for indications other than malignancy. A retrospective review of 44 patients who underwent revision
THA using a PFR between 2000 and 2013 was undertaken. Their mean
age was 79 years (53 to 97); 31 (70%) were women. The bone loss
was classified as Paprosky IIIB or IV in all patients. The mean
follow-up was six years (2 to 12), at which time 22 patients had
died and five were lost to follow-up.Aims
Patients and Methods
This multicentre, retrospective study aimed to improve our knowledge
of primary pyogenic spinal infections in children by analyzing a
large consecutive case series. The medical records of children with such an infection, treated
at four tertiary institutions between 2004 and 2014, were analyzed
retrospectively. Epidemiological, clinical, paraclinical, radiological,
and microbiological data were evaluated. There were 103 children,
of whom 79 (76.7%) were aged between six months and four years.Aims
Patients and Methods
In order to address acetabular defects, porous metal revision acetabular components and augments have been developed, which require fixation to each other. The fixation technique that results in the smallest relative movement between the components, as well as its influence on the primary stability with the host bone, have not previously been determined. A total of 18 composite hemipelvises with a Paprosky IIB defect were implanted using a porous titanium 56 mm multihole acetabular component and 1 cm augment. Each acetabular component and augment was affixed to the bone using two screws, while the method of fixation between the acetabular component and augment varied for the three groups of six hemipelvises: group S, screw fixation only; group SC, screw plus cement fixation; group C, cement fixation only. The implanted hemipelvises were cyclically loaded to three different loading maxima (0.5 kN, 0.9 kN, and 1.8 kN).Objectives
Methods
The primary stability of the cementless Oxford Unicompartmental Knee Replacement (OUKR) relies on interference fit (or press fit). Insufficient interference may cause implant loosening, whilst excessive interference could cause bone damage and fracture. The aim of this study was to identify the optimal interference fit by measuring the force required to seat the tibial component of the cementless OUKR (push-in force) and the force required to remove the component (pull-out force). Six cementless OUKR tibial components were implanted in 12 new slots prepared on blocks of solid polyurethane foam (20 pounds per cubic foot (PCF), Sawbones, Malmo, Sweden) with a range of interference of 0.1 mm to 1.9 mm using a Dartec materials testing machine HC10 (Zwick Ltd, Herefordshire, United Kingdom) . The experiment was repeated with cellular polyurethane foam (15 PCF), which is a more porous analogue for trabecular bone.Objectives
Materials and Methods
The pathogenesis of intraneural ganglion cysts is controversial.
Recent reports in the literature described medial plantar intraneural
ganglion cysts (mIGC) with articular branches to subtalar joints.
The aim of the current study was to provide further support for
the principles underlying the articular theory, and to explain the
successes and failures of treatment of mICGs. Between 2006 and 2017, five patients with five mICGs were retrospectively
reviewed. There were five men with a mean age of 50.2 years (33
to 68) and a mean follow-up of 3.8 years (0.8 to 6). Case history,
physical examination, imaging, and intraoperative findings were
reviewed. The outcomes of interest were ultrasound and/or MRI features
of mICG, as well as the clinical outcomes.Aims
Patients and Methods
We assessed the long-term (more than ten-year) outcomes of the
Kudo type-5 elbow prosthesis in patients with rheumatoid arthritis
(RA). We reviewed 41 elbows (Larsen Grade IV, n = 21; Grade V, n =
20) in 31 patients with RA who had undergone a Kudo type-5 total
elbow arthroplasty (TEA) between 1994 and 2003, and had been followed
up for more than ten years. The humeral component was cementless
and the all-polyethylene ulnar component cemented in every patient. Clinical
outcome was assessed using the Mayo elbow performance score. We
calculated the revision rate and evaluated potential risk factors
for revision. The duration of follow-up was a mean 141 months (120
to 203).Aims
Materials and Methods
The aim of the study was to compare measures of the quality of
life (QOL) after resection of a chordoma of the mobile spine with
the national averages in the United States and to assess which factors
influenced the QOL, symptoms of anxiety and depression, and coping
with pain post-operatively in these patients. A total of 48 consecutive patients who underwent resection of
a primary or recurrent chordoma of the mobile spine between 2000
and 2015 were included. A total of 34 patients completed a survey
at least 12 months post-operatively. The primary outcome was the
EuroQol-5 Dimensions (EQ-5D-3L) questionnaire. Secondary outcomes were
the Patient-Reported Outcome Measurement Information System (PROMIS)
anxiety, depression and pain interference questionnaires. Data which
were recorded included the indication for surgery, the region of
the tumour, the number of levels resected, the status of the surgical
margins, re-operations, complications, neurological deficit, length
of stay in hospital and rate of re-admission.Aims
Patients and Methods
The aim of this study was to determine whether the rates of revision
for metal-on-metal (MoM) total hip arthroplasties (THAs) with Pinnacle
components varied according to the year of the initial operation,
and compare these with the rates of revision for other designs of
MoM THA. Data from the National Joint Registry for England and Wales included
36 mm MoM THAs with Pinnacle acetabular components which were undertaken
between 2003 and 2012 with follow-up for at least five years (n
= 10 776) and a control group of other MoM THAs (n = 13 817). The
effect of the year of the primary operation on all-cause rates of revision
was assessed using Cox regression and interrupted time-series analysis.Aims
Patients and 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
We report the incidence of radiolucent lines (RLLs) using two
flanged acetabular components at total hip arthroplasty (THA) and
the effect of the Rim Cutter. We performed a retrospective review of 300 hips in 292 patients
who underwent primary cemented THA. A contemporary flanged acetabular
component was used with (group 1) and without (group 2) the use
of the Rim Cutter and the Rimfit acetabular component was used with
the Rim Cutter (group 3). RLLs and clinical outcomes were evaluated
immediately post-operatively and at five years post-operatively.Aims
Patients and Methods
