Metal-on-metal (MoM) articulations in total hip replacement (THR) have become an attractive option for young, active patients. Short-term reports have demonstrated elevated systemic metal ion levels in the blood and urine. Disseminated concentrations of cobalt and chromium have raised concern regarding cellular toxicity, chromosomal damage and adverse local soft tissue reactions. Long-term studies are required to support the increased use of MoM bearings in younger patients given their potential deleterious effects. The purpose of the current study was to report the seven to 13 year clinical, radiographic, and metal ion results in patients following MoM THR. We prospectively followed 165 patients (196 hips) after second-generation MoM THR between July 1997 and November 2003. Functional outcome was measured using the Harris Hip Score (HHS) and the University of California Los Angeles (UCLA) Activity Score. Radiographic analysis was performed using Einzel-Bild-Roentgen-Analyse (EBRA) by two of the authors blinded to the study. Cobalt and chromium metal ions were measured from whole blood and analyzed using inductively coupled plasma-mass spectrometry as previously described.Purpose
Method
The purpose of the study was to determine the rate of conversion from RSA to THR in a number of Canadian centers performing resurfacings Retrospective review was undertaken in 12 Canadian Centers to determine the rate of revision and reason for conversion from RSA to THR. Averages and cross-tabulation with Chi-Squared analysis was performed. kaplan Meier survivorship was calculated.Purpose
Method
Metal-on-metal (MoM) articulations in total hip replacement (THR) have become an attractive option for young, active patients. Short-term reports have demonstrated elevated systemic metal ion levels in the blood and urine. Disseminated concentrations of cobalt and chromium have raised concern regarding cellular toxicity, chromosomal damage and adverse local soft tissue reactions. Long-term studies are required to support the increased use of MoM bearings in younger patients given their potential deleterious effects. The purpose of the current study was to report the 7–13 year clinical, radiographic, and metal ion results in patients following MoM THR. We prospectively followed 165 patients (196 hips) after second-generation MoM THR between July 1997 and November 2003. Functional outcome was measured using the Harris Hip Score (HHS) and the University of California Los Angeles (UCLA) Activity Score. Radiographic analysis was performed using Einzel-Bild-Roentgen-Analyse (EBRA) by two of the authors blinded to the study. Cobalt and chromium metal ions were measured from whole blood and analyzed using inductively coupled plasma-mass spectrometry.Introduction
Methods
A major drawback of current cartilage and intervertebral disc (IVD) tissue engineering is that human mesenchymal stem cells (MSCs) from osteoarthritic (OA) patients express high levels of type X collagen. Type X collagen is a marker of late stage chondrocyte hypertrophy, linked with endochondral ossification, which precedes bone formation. However, it has been shown that a novel plasma-polymer, called nitrogen-rich plasma-polymerized ethylene (PPE:N), is able to inhibit type X collagen expression in committed MSCs. The aim of this study was to determine if the decreased expression of type X collagen, induced by the PPE:N surfaces is maintained when MSCs are removed from the surface and transferred to pellet cultures in the presence of serum and growth factor free chondrogenic media. Human MSCs were obtained from aspirates from the intramedullary canal of donors undergoing total hip replacement for OA. Cells were expanded for 2–3 passages and then cultured on polystyrene dishes and on two different PPE:N surfaces: high (H) and low (L) pressure deposition. Cells were transferred for 7 additional days in chondrogenic serum free media (DMEM high glucose supplemented with 2 mM L-glutamine, 20 mM HEPES, 45 mM NaHCO3, 100 U/ml penicillin, 100 ug/ml streptomycin, 1 mg/ml bovine serum albumin, 5 ug/ml insulin, 50 ug/ml ascorbic acid, 5 ng/ml sodium selenite, 5 ug/ml transferrin) in pellet culture or on PS cell culture dishes. RNA was extracted using a standard TRIzol protocol. RT-PCR was realized using Superscript II (RT) and Taq polymerase (PCR) with primers specific for type I and X collagen. GAPDH was used as a housekeeping gene and served to normalize the results.Purpose
Method
Disc degeneration is known to occur early in adult life, but at present there is no medical treatment to reverse or even retard the problem. Development of medical treatments is complicated by the lack of a validated long term organ culture model in which therapeutic candidates can be studied. The objective of this study was to optimize and validate an organ culture system for intact human intervertebral disc (IVD), which could be used subsequently to determine whether synthetic peptide growth factors can stimulate disc cell metabolism and initiate a repair response. Seventy lumbar IVDs, from 14 individuals, were isolated within 24 h after death. Discs were prepared for organ culture by removing bony endplates but retaining cartilaginous endplates (CEP). Discs were cultured with no external load applied. The effects of glucose and FBS concentrations were evaluated. Dulbeccos Modified Eagle Media (DMEM) was supplemented with glucose, 4.5g/L or 1g/L, referred to as high and low (physiological) glucose, and FBS, 5% or 1%, referred to as high and low FBS, respectively. After a four week culture period, samples were taken across the disc using a 4 mm biopsy punch. Cell viability was analyzed using a live/dead fluorescence assay (Live/Dead, Invitrogen) and visualized by confocal microscopy. CEP discs were also placed in long term culture for four months, and cell viability was assessed. Western bolt analysis for the G1 domain of aggrecan was also performed to assess the effect of nutritional state on disc catabolism.Purpose
Method
Whilst it is known that oxidative stress can cause early degenerative changes observed in experimental osteoarthritis and that a major drawback of current cartilage and intervertebral disc tissue engineering is that human mesenchymal stem cells (MSCs) from osteoarthritis (OA) patients express type X collagen, a marker of late-stage chondrocyte hypertrophy (associated with endochondral ossification), little is known whether the expression of type X collagen in MSCs from OA patients can be related to oxidative stress or inflammatory reactions that occur during this disease. Human MSCs were obtained from aspirates from the intramedullary canal of donors undergoing total hip replacement for OA. Bone marrow aspirates were processed essentially as previously described. Briefly, non-adherent cells were discarded after 72h of culture and the adherent ones were expanded for 2–3 passages. MSCs from normal donor (control) were obtained from Lonza. Cells were then lysed and protein expression was detected by Western blot using specific antibodies directed against type X collagen, as well as the antioxidant enzymes Mn-superoxide dismutase (MnSOD), catalase (CAT) and glutathione peroxidase-1 (GPx-1) and inflammation related proteins cyclooxygenase-1 (COX-1) and intercellular adhesion molecule-1 (ICAM-1). GAPDH was used as a housekeeping gene and served to normalize the results. Correlations between the expressions of the different proteins were realized using the correlation Z test with StatView (SAS Institute).Purpose
Method
Co and Cr concentrations were measured in both the seminal plasma and in the blood of patients by inductively coupled plasma-mass spectroscopy (ICP-MS).
Patients having metal-on-polyethylene THA or resurfacing without pain (Control group), Patients having MOM THA or resurfacing with high levels of metal ions (cobalt and chromium) and having pain Patients having MOM THA or resurfacing with high levels of metal ions but having no pain and Patients having MOM THA or resurfacing with low levels of metal ions and having no pain. Operated hips were evaluated with MRI by one musculoskeletal radiologist who was blinded to the radiographic findings and clinical symptoms. All images were assessed for the presence of a juxtaarticular or periprosthetic abnormalities, including fluid collections, soft tissue masses, osseous abnormalities, and patterns of contrast enhancement of lesions.