Aims. With increasing burden of revision hip arthroplasty (THA), one of the major challenges is the management of proximal femoral bone loss associated with previous multiple surgeries. Proximal femoral arthroplasty (PFA) has already been popularized for tumour surgeries. Our aim was to describe the outcome of using PFA in these demanding non-neoplastic cases. Methods. A retrospective review of 25 patients who underwent PFA for non-neoplastic indications between January 2009 and December 2015 was undertaken. Their clinical and radiological outcome, complication rates, and survival were recorded. All patients had the Stanmore Implant – Modular Endo-prosthetic Tumour System (METS). Results. At mean follow-up of 5.9 years, there were no periprosthetic fractures. Clearance of infection was achieved in 63.6% of cases. One hip was re-revised to pseudo arthroplasty for deep infection. Instability was noted in eight of the hips (32%), of which seven needed further surgery. Out of these eight hips with instability, five had preoperative infection. Deep infection was noted in five of the hips (20%), of which four were primarily revised for infection. One patient had aseptic loosening of the
The first 325 Exeter Universal stems (309 patients) implanted at the originating centre were inserted between March 1988 and February 1990 by a group of surgeons with differing experience. In this report we describe the clinical and radiological results at a mean of 15.7 years (14.7 to 17.3) after operation with no loss to follow-up. There were 97 patients (108 hips) with replacements still in situ and 31 (31 hips) who had undergone a further procedure. With an endpoint of revision for aseptic loosening, the survivorship at 17 years was 100% and 90.4% for the femoral and acetabular component, respectively. The mean Merle D’Aubigné and Postel scores at review were 5.4 (. sd. 0.97) for pain and 4.5 (. sd. 1.72) for function. The mean Oxford score was 38.4 (. sd. 9.8) (0 to 48 worst-to-best scale) and the mean combined Harris pain and function score was 73.2 (. sd. 16.9). Radiological review showed excellent preservation of bone stock in the proximal femur and no failures of the
We carried out a histological study of a proximally hydroxyapatite (HA)-coated
Roentgen stereophotogrammetric analysis was used to measure the migration of 24 cemented
This study explored the relationship between the initial stability of the
We studied 16 femora retrieved at post-mortem from symptomless patients who had a satisfactory cemented total hip arthroplasty from two weeks to 17 years earlier, with the aim of delineating the initial mechanisms involved in loosening. Only one specimen showed radiographic evidence of loosening; the other 15 were stable to mechanical testing at 17.0 Nm of torque. In all 16 specimens, the cement-bone interface was intact with little fibrous tissue formation. By contrast, separation at the cement-prosthesis interface and fractures in the cement mantle were frequent. The most common early feature was debonding of the cement from the metal, seen at the proximal and distal ends of the prosthesis. Specimens which had been in place for longer also showed circumferential fractures in the cement, near the cement-metal interface, and radial fractures extending from this interface into the cement and sometimes to the bony interface. The most extensive cement fractures appeared to have started at or near sharp corners in the metal, or where the cement mantle was thin or incomplete. Fractures were also related to voids in the cement. The time relationship in this series suggested that long-term failure of the fixation of cemented
Mechanical and biomechanical testing of a new bone cement suggests that improved load transfer to the proximal femur could be achieved with the combination of a cement having a lower modulus, a greater ductility and a lower creep resistance than polymethylmethacrylate and a suitably shaped
Aims. The surgical target for optimal implant positioning in robotic-assisted total knee arthroplasty remains the subject of ongoing discussion. One of the proposed targets is to recreate the knee’s functional behaviour as per its pre-diseased state. The aim of this study was to optimize implant positioning, starting from mechanical alignment (MA), toward restoring the pre-diseased status, including ligament strain and kinematic patterns, in a patient population. Methods. We used an active appearance model-based approach to segment the preoperative CT of 21 osteoarthritic patients, which identified the osteophyte-free surfaces and estimated cartilage from the segmented bones; these geometries were used to construct patient-specific musculoskeletal models of the pre-diseased knee. Subsequently, implantations were simulated using the MA method, and a previously developed optimization technique was employed to find the optimal implant position that minimized the root mean square deviation between pre-diseased and postoperative ligament strains and kinematics. Results. There were evident biomechanical differences between the simulated patient models, but also trends that appeared reproducible at the population level. Optimizing the implant position significantly reduced the maximum observed strain root mean square deviations within the cohort from 36.5% to below 5.3% for all but the anterolateral ligament; and concomitantly reduced the kinematic deviations from 3.8 mm (SD 1.7) and 4.7° (SD 1.9°) with MA to 2.7 mm (SD 1.4) and 3.7° (SD 1.9°) relative to the pre-diseased state. To achieve this, the
We describe a case of symptomatic focal femoral osteolysis around a screw hole distal to the hydroxyapatite-coated portion of a cannulated
Several methods of measuring the migration of the
Aims. The objectives of this study were to investigate the patient characteristics and mortality of Vancouver type B periprosthetic femoral fractures (PFF) subgroups divided into two groups according to
Bone mineral density (BMD) around the
Aims. We have previously reported the mid-term outcomes of revision total knee arthroplasty (TKA) for flexion instability. At a mean of four years, there were no re-revisions for instability. The aim of this study was to report the implant survivorship and clinical and radiological outcomes of the same cohort of of patients at a mean follow-up of ten years. Methods. The original publication included 60 revision TKAs in 60 patients which were undertaken between 2000 and 2010. The mean age of the patients at the time of revision TKA was 65 years, and 33 (55%) were female. Since that time, 21 patients died, leaving 39 patients (65%) available for analysis. The cumulative incidence of any re-revision with death as a competing risk was calculated. Knee Society Scores (KSSs) were also recorded, and updated radiographs were reviewed. Results. The cumulative incidence of any re-revision was 13% at a mean of ten years. At the most recent-follow-up, eight TKAs had been re-revised: three for recurrent flexion instability (two fully revised to varus-valgus constrained implants (VVCs), and one posterior-stabilized (PS) implant converted to VVC, one for global instability (PS to VVC), two for aseptic loosening of the
Aims. To investigate the longevity of uncemented fixation of a femoral
component in total hip arthroplasty (THA) in patients with Dorr
type C proximal femoral morphology. Patients and Methods. A total of 350 consecutive uncemented THA in 320 patients were
performed between 1983 and 1987, by a single surgeon using the Taperloc
femoral component. The 63 patients (68 hips) with Dorr type C proximal
femoral morphology were the focus of this review. The mean age of
the patients was 69 years (24 to 88) and mean follow-up was 16.6
years (ten to 29). Survival analysis included eight patients (eight
hips) who died without undergoing revision surgery prior to obtaining
ten years follow-up. All 55 surviving patients (60 hips) were available
for clinical assessment and radiographic review. As a comparator
group, the survival and implant fixation in the remaining 282 THAs
(257 patients) with Dorr type A and B morphology were evaluated.
The mean age of these patients was 52 years (20 to 82). Results. In the Dorr C patient group the mean Harris hip score improved
from 51 points (21 to 69 points) pre-operatively to 89 (74 to 100)
at final follow-up. No
Four cases are described of localised endosteal bone lysis in the femur occurring in association with cemented
We describe our experience with the implantation of 325 Exeter Universal hips. The fate of every implant was known. The procedures were undertaken by surgeons of widely differing experience. At follow-up at 12 years, survivorship with revision of the
We implanted 57 uncemented cobalt-chrome porous-coated collarless
We report the preliminary findings of the use of roentgen stereophotogrammetric analysis to evaluate the early migration of five
We investigated the effect of pre-heating a
Oxidised zirconium was introduced as a material for femoral components
in total knee arthroplasty (TKA) as an attempt to reduce polyethylene
wear. However, the long-term survival of this component is not known. We performed a retrospective review of a prospectively collected
database to assess the ten year survival and clinical and radiological
outcomes of an oxidised zirconium total knee arthroplasty with the
Genesis II prosthesis. The Western Ontario and McMaster Universities Osteoarthritis
Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS)
and a patient satisfaction scale were used to assess outcome.Aims
Methods