Background. The worldwide withdrawal of the DePuy Articular Surface Replacement (ASR) device in both its resurfacing and total hip replacement (THR) form on 26 August 2010, after 93,000 were implanted worldwide, has had major implications. The 2010 National Joint Registry for England and Wales quoted figures of 12-13% failure at five years; however these figures may be an underestimate. Patients and methods. In 2004 a single surgeon prospective study of the
Hip resurfacing has generally been used in younger patients with early osteoarthritis of the hip. There has been considerable recent interest in this over the past few years. We conducted a prospective randomised trial comparing 2 hip resurfacing implants, Durom and
We present the mid-term results of our consecutive series of 155 hips treated with
The articulating surface replacement (ASR) XL stemmed total hip replacement and
Introduction:. We present the mid-term results of our consecutive series of 155 hips treated with
Introduction. Failure rates of Metal-on-Metal (MoM)
Introduction. While fixation on the acetabular side in resurfacing implants has been uncemented, the femoral component is usually cemented. The most common causes for early revision in hip resurfacing are femoral head and or neck fractures and aseptic loosening of the femoral component. Later failures appear to be more related to adverse soft-tissue reactions due to metal wear. Little is known about the effect of cementing techniques on the clinical outcome in hip resurfacing, since retrieval analysis of failed hip resurfacing show large variations. Two cementing techniques have dominated. The indirect low viscosity (LV) technique as for the Birmingham Hip resurfacing (BHR) system and the direct high viscosity (HV) technique as for the Articular Surface replacement (ASR) system. The
Introduction: Excellent medium term results have been reported with the BHR hip resurfacing implant. A number of modifications have been made to the latest designs in an attempt to preserve acetabular bone stock, improve function and prolong survival. We present the clinical and radiological results from the first independent series of
Aim. We report the results of 60 patients who were assessed using the Oxford Hip Score following surgery for revision of ASL XL and
Background. Previous studies have indicated poor outcomes and high complication rate in patients having revision of metal-on-metal (MoM) hip implants resulting from adverse local tissue reactions. Metal ions released by MoM bearings may potentially increase infection occurrence in patients with failed implants. Questions/purposes. We reviewed all patients at our institution who sustained revision of a failed large-head metal-on-metal hip implant to determine if infection-related complications are associated with the elevation of serum metal ions concentration. Methods. From December 2005 to April 2013, we performed 44 revisions of large-head MoM total hip arthroplasty (THA) and resurfacing in 44 patients. In all revision procedures MoM couplings (ASR XL Acetabular System and DePuy
Introduction: There is a general conception in the orthopaedic community that blood loss/transfusion rate in hip resurfacing procedures is greater than that conventional Total Hip Arthroplasty (THA). The theoretical basis is that uncemented procedures leave large bleeding bone surfaces and that resurfacing arthroplasty needs larger incisions, greater exposure and more extensive soft tissue releases. Although this theory has gained informal. Acceptance in orthopaedic practice, there is little evidence in the literature to support this. Background The purpose of this study was to determine the actual blood loss and transfusion rate (including hidden blood loss) in a consecutive cohort of patients undergoing hip re-surfacing by a single surgeon using the Articular Surface Replacement (ASR – DePuy). Materials and Methods: The cohort consisted of 58 patients who were followed prospectively. All patients underwent a standardized surgical procedure performed by one senior surgeon. Hypotensive anaesthesia was used in all cases and surgery was via a standard posterior approach. Drains were not routinely placed, but if used, were removed within 24 hours. Low Molecular Weight Heparin was given 24 hours post procedure until discharge. Surgical blood loss was calculated in a standard fashion (suction volume plus swab weight). Drain volume (if used) was added after removal at 24 hours. Unseen loss of blood in soft tissues, joint space, as well as loss due to haemolysis, is calculated by the modified formula of Kallos. 1. :. \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \[MABL=\ EBV\ x\ (\underline{Hct\ pt\ -\ Hct\ min})\] \end{document}. Hct pt, Where is. MABL = Maximum allowable blood loss. EBV =Estimated blood volume, 70 ml/kg. Hct pt= Pre operative haematocrit of patient. Hct min=Minimum allowable haematocrit. This was modified to. \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(ABL=\ EBV\ {\times}\ \frac{(Hct\ pre\ op\ {-}\ Hct\ post\ opD2)}{Hct\ pre\ op}\) \end{document}. where is. ABL= Actual blood loss, Unseen loss = ABL – Visible loss (Loss in OT + Drain). Results: 58 Patients undergoing
In 2010, a widely used metal-on-metal hip implant was voluntarily recalled from the market by the manufacturer. Our lab performed detailed retrieval analysis of 548 of the explanted devices and 165 periprosthetic tissue specimens. We reported a high degree of variability in the multiple measurements that we performed on the components, including volumetric wear. Other studies using semi-quantitative tissue grading methods to describe the histology of the periprosthetic tissues from metal-on-metal hips have looked for relationships between component wear and histological features. Grammatopoulos et al found higher ALVAL scores in 45 hip resurfacing patients with pseudotumors compared to 11 without pseudotumors and a moderately positive correlation between wear and the histological rankings for tissue necrosis and lymphocytic response. We examined correlations between the component wear measurements from retrieval analysis and the tissue features in this large group of one metal-on-metal hip design. Tissues were processed routinely into paraffin sections, stained with H&E and characterized with light microscopic semi-quantitative scores for ALVAL features and for the number of macrophages and lymphocytes, extent of metal debris and the estimated percentage of necrosis per slide. Spearman correlation analysis was conducted to evaluate any correlations between retrieval wear measurements and histological findings.Introduction
Materials and Methods
The objective of this study was to analyze the biomechanical effect of an implanted ACL graft by determining the tunnel position according to the aspect ratio (ASR) of the distal femur during flexion-extension motion. To analyze biomechanical characteristics according to the
Objectives. This study aimed to characterise and qualitatively grade the severity of the corrosion particles released into the hip joint following taper corrosion. Methods. The 26 cases examined were CoC/ABG Modular (n = 13) and
Aim. Infected segmental defects are one of the most feared complications of open tibial fractures. This may be due to prolonged treatment time, permanent functional deficits and high reinfection and non-union rates. Distraction osteogenesis techniques such as Ilizarov acute shortening with bifocal relengthening (ASR) and bone transport (BT) are effective surgical treatment options in the tibia. The aim of this study was to compare ASL with bone transport in a consecutive series of complex tibial infected non-unions and osteomyelitis, for the reconstruction of segmental defects created at surgical resection of the infection. Method. In this single centre series, all patients with a segmental defect (>2cm) of the tibia after excision of infected non-union or osteomyelitis were eligible for inclusion. Based on clinical features, bone reconstruction was achieved with either
Background. The failure and subsequent withdrawal of the
Summary. Despite high revision rates, the mean two year migration of the
The spine is one of the most common sites of bony metastasis, with 80% of prostate, lung, and breast cancers metastasizing to the vertebrae resulting in significant morbidity. Current treatment modalities are systemic chemotherapy, such as Doxorubicin (Dox), administered after resection to prevent cancer recurrence, and systemic antiresorptive medication, such as Zolendronate (Zol), to prevent tumor-induced bone destruction. The large systemic doses required to elicit an adequate effect in the spine often leads to significant side-effects by both drugs, limiting their prolonged use and effectiveness. Recently published work by our lab has shown that biocompatible 3D-printed porous polymer scaffolds are an effective way of delivering Dox locally over a sustained period while inhibiting tumor growth in vitro. Our lab has also generated promising results regarding antitumor properties of Zol in vitro. We aim to develop 3D-printed scaffolds to deliver a combination of Zol and Dox that can potentially allow for a synergistic antitumor activity while preventing concurrent bone loss locally at the site of a tumor, avoiding long systemic exposure to these drugs and decreasing side effects in the clinical setting. The PORO Lay polymer filaments are 3D-printed into 5mm diameter disks, washed with deionized water and loaded with Dox or Zol in aqueous buffer over 7 days. Dox or Zol-containing supernatant was collected daily and the drug release was analyzed over time in a fluorescence plate reader. The polymer-drug (Dox or Zol) release was tested in vitro on prostate and lung cancer cell lines and on prostate- or lung-induced bone metastases cells. Alternatively, direct drug treatment was also carried out on the same cells in vitro. Following treatment, all cells were subject to proliferation assay (MTT and alamar blue), viability assay (LIVE/DEAD), migration assay (Boyden chamber) and invasion assay (3D gel matrix). 3D-printed scaffolds loaded with both Dox and Zol will also be tested on cells. We have established an effective dose (EC50) for prostate and lung cancer cell lines and bone metastases cells with direct treatment with Zol or Dox. We have titrated the drug loading of scaffolds to allow for a release amount of Dox at the EC50 dose over 7 days. In ongoing experiments, we are testing the release of Zol. We have shown Dox releasing scaffolds inhibit cancer cell growth in a 2D culture over 7 days using the above cellular assays and testing the scaffolds with Zol is currently being analyzed. 3D-printed porous polymers like the PORO Lay series of products offer a novel and versatile opportunity for delivery of drugs in future clinical settings. They can decrease systemic exposure of drugs while at the same time concentrating the drugs effect at the site of tumors and consequently inhibit tumor proliferation. Their ability to be loaded with multiple drugs can allow for achieving multiple goals while taking advantage of synergistic effects of different drugs. The ability to 3D-print these polymers can allow for production of custom implants that offer better structural support for bone growth.
Hip resurfacing may be a useful surgical procedure when patient selection is correct and only implants with superior performance are used. In order to establish a body of evidence in relation to hip resurfacing, pseudotumour formation and its genetic predisposition, we performed a case-control study investigating the role of HLA genotype in the development of pseudotumour around MoM hip resurfacings. All metal-on-metal (MoM) hip resurfacings performed in the history of the institution were assessed. A total of 392 hip resurfacings were performed by 12 surgeons between February 1st 2005 and October 31st 2007. In all cases, pseudotumour was confirmed in the preoperative setting on Metal Artefact Reduction Sequencing (MARS) MRI. Controls were matched by implant (ASR or BHR) and absence of pseudotumour was confirmed on MRI. Blood samples from all cases and controls underwent genetic analysis using Next Generation Sequencing (NGS) assessing for the following alleles of 11 HLA loci (A, B, C, DRB1, DRB3/4/5, DQA1, DQB1, DPB1, DPA1). Statistical significance was determined using a Fisher's exact test or Chi-Squared test given the small sample size to quantify the clinical association between HLA genotype and the need for revision surgery due to pseudotumour. Both groups were matched for implant type (55%
In our independent centre, from 2002 to 2009, 155 BHRs (mean F/U 60 months) have been implanted as well as 420