Paul Johan Høl

Haukeland University Hospital · Orthopedic Clinic

Background: A BHR (Birmingham hip resurfacing) prosthesis was implanted in 445 people in Norway. Adverse reactions can arise as a result of the release of metal ions from metal-on-metal joint surfaces made from cobalt-chromium alloy. The aim of the study was to analyse the release of metal ions during the first five years after surgery in patients...

The cemented Spectron EF stem in combination with the cemented non‐crosslinked Reflection All‐Poly cup showed a high rate of mid‐term aseptic loosening. However, the failure mechanisms are not fully known. We assessed the inflammatory tissue reactions and wear particles in periprosthetic tissues, implant wear and blood metal ion levels in 28 patien...

Polycrystalline diamond has the potential to improve the osseointegration of orthopedic implants compared to conventional materials such as titanium. However, despite the excellent biocompatibility and superior mechanical properties, the major challenge of using diamond for implants, such as those used for hip arthroplasty, is the limitation of mic...

The use of inert head materials such as ceramic heads has been proposed as a method of reducing wear and corrosion products from the articulating surfaces in total hip arthroplasty, as well as from the stem‐head taper connection. The aim of the present study was to compare the blood metal ion levels in patients with Oxinium and CoCrMo modular femor...

Background Cementing technique in total knee arthroplasty (TKA) may influence implant survival. There is limited knowledge about the results with clinically used techniques. The aim of this study was to investigate cementing techniques for TKA in Norwegian hospitals, to compare widely used techniques to recommendations from the literature, and to i...

Polycrystalline diamond has the potential to improve the osseointegration of orthopaedic implants compared to conventional materials such as titanium. However, despite the excellent biocompatibility and superior mechanical properties, the major challenge of using diamond for implants, such as those used for hip arthroplasty, is the limitations of m...

Background and purpose The use of inert head materials such as ceramic heads has been proposed as a method of reducing wear and corrosion products from the articulating surfaces in total hip arthroplasty (THA), as well as from the stem-head taper connection. In the present study, we wanted to evaluate the blood metal ion levels of Oxinium modular f...

Polycrystalline diamond has the potential to improve the osseointegration of orthopaedic implants compared to conventional osteo-implant materials such as titanium. However, despite the excellent biocompatibility and superior mechanical properties, the major challenge of using diamond for implants such as those used for hip arthroplasty is the limi...

Background: A BHR (Birmingham hip resurfacing) prosthesis was implanted in 445 people in Norway. Adverse reactions can arise as a result of the release of metal ions from metal-on-metal joint surfaces made from cobalt-chromium alloy. The aim of the study was to analyse the release of metal ions during the first five years after surgery in patients...

The aim of the study was to compare side-to-side with step-cut repairs to determine how much of the width it is possible to remove and still keep the repair strong enough to start active mobilization. Porcine flexor tendons were used to create side-to-side, one-third step-cut and half step-cut repairs. There were 15 repairs in each group. The tensi...

Background and purpose — The optimal cementing technique for primary total knee arthroplasty (TKA) remains unclear. We therefore performed a scoping review based on available studies regarding cementation technique in primary TKA and unicondylar knee arthroplasty (UKA). Patients and methods — A search in 3 databases identified 1,554 studies. The in...

The aim of the study was to present two new modifications of the Pulvertaft weave, allowing a higher number of weaves without the need for a longer overlap. The mechanical properties were measured and compared with the traditional technique. Forty-five pairs of porcine flexor tendons were randomized to a Pulvertaft repair with three weaves, a Doubl...

Den heller restriktive, men fornuftige holdningen til norske ortopeder har forhindret at dårlige og potensielt farlige produkter settes inn i pasienter, skriver artikkelforfatterne. Leddproteseregisteret viser at registre over klinisk data gir bedre pasientbehandling. Etter vår mening bør registerdata suppleres med mer detaljert undersøkelse av uts...

Intra-arterial stenosis due to atherosclerosis is often treated with endovascular balloon dilatation with a metal stent. Restenosis is common and is frequently treated with a new stent placed inside the existing one or the stents are placed with overlap to cover a larger area of the vessels. Observations of stent fractures, stent compression, accum...

The evaluation of the biological effects of endoprosthetic wear particles on cells in vitro relies on a variety of test assays. However, most of these methods are susceptible to particle-induced interferences; therefore, label-free testing approaches emerge as more reliable alternatives. In this study, impedance-based real-time monitoring of cellul...

Titanium is used in a wide variety of materials ranging from medical devices to materials used in everyday life. Adverse biological reactions that could occur in patients, consumers, and workers should be monitored and prevented. There is a lack of available agents to test and predict titanium-related hypersensitivity. The aim of this study was to...

Patient specific forecasting tools are an area of active research and very much seen as a necessary tool for future improvements in healthcare. In order to succeed with decision making tools, fine-grained data are required to build models relevant and valid at an individual level. Location and assemble of data to build such tools is not trivial. Ev...

Background and purpose Registry-based studies have reported an increased risk of aseptic tibial loosening for the cemented Low Contact Stress (LCS) total knee replacement compared with other cemented designs; however, the reasons for this have not been established. We made a retrieval analysis with the aim of identifying the failure mechanism. Pat...

Osteolysis in the periprosthetic tissue can be caused by metallic wear particles and ions that can originate from implant surface corrosion. These products influence cellular behavior and stimulate the expression of proinflammatory cytokines. The purpose of this study was to evaluate the impact of CoCr29Mo6 ions on cell survival, differentiation, a...

Pregnant women and infants are at risk for selenium deficiency, which is known to have negative effects on immune and brain function. We have investigated selenium levels in 158 healthy never-pregnant women and in 114 pregnant and lactating women and their infants at age 6 months and related this to clinical outcomes during the first 6 months of li...

Protein adsorption onto nanoparticles (NPs) in biological fluids has emerged as an important factor when testing biological responses to NPs, as this may influence both uptake and subsequent toxicity. The aim of the present study was to quantify the adsorption of proteins onto TiO2 NPs and to test the influence on cellular uptake. The surface compo...

Objective: The LCS Complete mobile-bearing implant (LCS) is a widely used total knee replacement (TKR). Recently Norwegian (Gøthesen 2013) and American (Namba 2013) registry data has detected a lower survivorship of the LCS compared to other TKR. Specifically the relative risk for aseptic tibial loosening was 7.7 higher for the LCS when compared to...

Wear debris-induced inflammation is considered to be the main cause for periprosthetic osteolysis in total hip replacements (THR). The objective of this retrieval study was to examine the tissue reactions and exposure to metal ions and wear particles in periprosthetic tissues and blood samples from patients with titanium (Ti)-based hip prostheses t...

Introduction: Many factors have been suggested to contribute to restenosis in intra arterial stents. Observations of stent fractures, stent compression, accumulation of immune competent cells around stents have led to an interest in stent surface design and the possibility of immunologic reactions to the stents. Stents are often placed inside stent...

Summary Particulate wear debris with different chemical composition induced similar periprosthetic tissue reactions in patients with loosened uncemented and cemented titanium hip implants, which suggests that osteolysis can develop independent of particle composition. Introduction Periprosthetic osteolysis is a serious long-term complication in to...

The relative risk of revision of the Titan(®) femoral stem due to aseptic loosening increased after 2000; however, the reasons for this have not been established. A retrieval analysis was initiated with the aim of delineating the failure mechanism. We asked whether aseptic loosening in stems after 2000 was associated with (1) appearance of osteolyt...

The relation between the physico-chemical properties of nanoparticles (NPs) and the degree of cellular uptake is incompletely elucidated. In this study, we investigated the influence on the cellular uptake of a wide range of fully characterized TiO(2) NPs. L929 fibroblasts were exposed for 24h to clinically relevant concentrations of nano-TiO(2) an...

Despite the fact that there have been some reports on poor performance, titanium femoral stems intended for cemented fixation are still used at some centers in Europe. In this population-based registry study, we examined the results of the most frequently used cemented titanium stem in Norway. 11,876 cases implanted with the cemented Titan stem wer...

J Oral Pathol Med (2011) 40: 412–420 The present study examines the quantity, size, element signatures and distribution of titanium particles in normal oral mucosal tissue and in oral mucosa exposed to a titanium implant. Tissue samples from six healthy patients were obtained by a full thickness biopsy taken from the edge of the oral mucosa when in...

The physicochemical characterization of nanoparticles in suspension is a prerequisite for the adequate assessment of their potential biological effect. Little is known to date about the colloidal stability of TiO2 nanoparticles in cell culture medium. This study investigates the effect of particle concentration, ionic strength, pH, and the presence...

The cellular responses to degradation products from titanium (Ti) implants are important indicators for the biocompatibility of these widely used implantable medical devices. The potential toxicity of nanoparticulate matter released from implants has been scarcely studied. The aim of this study was to investigate the potential of TiO2 nanoparticles...

It is recommended that one should not combine different metals in orthopaedic devices. The least noble metal in such a galvanic coupling is more likely to corrode. However, some studies have failed to show increased corrosion when titanium and stainless steel are combined. The aim of this study was to determine the fretting corrosion of the contact...

Degradation products of titanium implants include free ions, organo-metallic complexes, and particles, ranging from nano to macro sizes. The biological effects, especially of nanoparticles, is yet unknown. The main objective of this study was to develop Ti-protein antigens in physiological solutions that can be used in testing of cellular responses...

Hip fractures are disabling accidents in the elderly. The purpose of this prospective study was to investigate systemic exposure to metals from hip implants used for fracture fixation. Serum levels of Cr, Ni and Mo in patients with compression hip screws (n = 22) or cervical fracture screws (n = 23) were measured by inductively coupled plasma mass...

At the outset of a clinical research project involving metal analyses on patients receiving metal devices in conjunction with hip fractures, unexpected high concentrations of nickel were discovered in serum samples taken before surgery. The median nickel concentration in 30 patients was 4.6 microg/l (highest 19.5 microg/l), while reference values i...

Results are reported from a study on the in vitro separation and identification of leachables from three different polymer-based dental filling materials by using a combined method of gas chromatography and mass spectrometry. The median number of separable organic leachables in these materials was between 14 and 22. Of these organic leachables the...

The use of DMPS as a diagnostic tool in patients with symptoms allegedly caused by mercury from dental amalgam fillings is disputed. We have previously shown that the mercury concentrations in urine cannot be used in such a way. In the present study, we wished to evaluate the effect on blood mercury levels (B-Hg) following intravenously injected DM...

This study investigated the effects of a single dose of intravenously administered sodium 2,3-dimercaptopropane-1-sulfonate (DMPS) on the essential elements copper, zinc, and selenium in human blood and urine. The possible role of dental amalgam was also addressed. Eighty individuals, divided in four groups according to the presence or absence of d...

Selenium may have a protective effect against mercury toxicity. The aim of the present study was to investigate if selenium excretion in urine was affected in persons with dental amalgam fillings. The reason for this study is that dental amalgam is the most important source of inorganic mercury exposure in the general population, although the poten...

It has been suggested that selenium (Se) exhibits protective effects against mercury (Hg) toxicity in humans due to formation of a Hg-Se complex bound to selenoprotein P in blood. The aim of the present study was to investigate Se concentrations in persons who had been examined with respect to general health problems associated with dental amalgam...

The chelating agent 2,3 dimercaptopropane-1-sulfonate (DMPS) has been used in a mercury mobilization test for diagnoses in illnesses allegedly associated with the presence of amalgam restorations. DMPS is an accepted antidote to heavy metal poisoning. The aim of the present study was to evaluate the diagnostic value of DMPS in patients with symptom...

The amount of mercury released into saliva from dental amalgam fillings is currently being debated. Mercury enters saliva as vapor, ions and particles of amalgam. The aim of the present study was to determine mercury and silver concentrations in saliva of persons with amalgam fillings. Moreover, it was the aim to investigate whether amalgam particl...

Results are reported from a study on the in vitro separation and identification of leachables from three different polymer-based dental filling materials by using a combined method of gas chromatography and mass spectrometry. The median number of separable organic leachables in these materials was between 14 and 22. Of these organic leachables the...

Rhododendron leaves were collected from 10 sites in Bergen, Norway and analyzed for lead and cadmium by graphite furnace atomic absorption spectrometry. The data were subjected to multivariate analysis to examine the relationship between measured metal concentrations and variables including relative traffic density, distance from the roadside, and...