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Sample records for metal-on-metal resurfacing hip

  1. Metal-on-Metal Hip Resurfacing Arthroplasty

    PubMed Central

    Sehatzadeh, S; Kaulback, K; Levin, L

    2012-01-01

    Background Metal-on-metal (MOM) hip resurfacing arthroplasty (HRA) is in clinical use as an appropriate alternative to total hip arthroplasty in young patients. In this technique, a metal cap is placed on the femoral head to cover the damaged surface of the bone and a metal cup is placed in the acetabulum. Objectives The primary objective of this analysis was to compare the revision rates of MOM HRA using different implants with the benchmark set by the National Institute of Clinical Excellence (NICE). The secondary objective of this analysis was to review the literature regarding adverse biological effects associated with implant material. Review Methods A literature search was performed on February 13, 2012, to identify studies published from January 1, 2009, to February 13, 2012. Results The revision rates for MOM HRA using 6 different implants were reviewed. The revision rates for MOM HRA with 3 implants met the NICE criteria, i.e., a revision rate of 10% or less at 10 years. Two implants had short-term follow-ups and MOM HRA with one of the implants failed to meet the NICE criteria. Adverse tissue reactions resulting in failure of the implants have been reported by several studies. With a better understanding of the factors that influence the wear rate of the implants, adverse tissue reactions and subsequent implant failure can be minimized. Many authors have suggested that patient selection and surgical technique affect the wear rate and the risk of tissue reactions. The biological effects of high metal ion levels in the blood and urine of patients with MOM HRA implants are not known. Studies have shown an increase in chromosomal aberrations in patients with MOM articulations, but the clinical implications and long-term consequences of this increase are still unknown. Epidemiological studies have shown that patients with MOM HRA implants did not have an overall increase in mortality or risk of cancer. There is insufficient clinical data to confirm the

  2. Present state of metal-on-metal hybrid hip resurfacing.

    PubMed

    Amstutz, Harlan C

    2008-01-01

    Bone conservation and preservation, joint stability, and low wear of the large metal-on-metal resurfacing bearings have been convincingly demonstrated in the current literature. The clinical results of 600 MM Hybrid Conserve Plus Resurfacing in 519 patients with an average follow-up of 6.9 years (range, 4.0-10.4 years) have been excellent. The average age was 48.9 years, 74% of the patients were male, and the study included all etiologies of the young with arthritis. The complication rates other than dislocation and fracture of the femoral neck are comparable between resurfacing and conventional total hip replacement. The incidence of femoral neck fracture is low (1.2% worldwide) with less than 0.6% in this series and none occurring in the last 5 years due to proper patient selection and improved surgical technique. Component loosening after metal-on-metal resurfacing has been significantly reduced and acetabular component loosening is uncommon and has not happened in this series. Femoral bone preparation and optimal cementing techniques are paramount to prevention of femoral loosening. Clearance between the cylindrically reamed part of the head and the component varies in different designs, and the surgeon must note the need for different cementing strategies for different recommended clearances. The learning curve of a surgeon undertaking resurfacing can be greatly reduced by observation and hands-on training in specialized centers with surgeons experienced in resurfacing.

  3. Metal-on-Metal Total Hip Resurfacing Arthroplasty

    PubMed Central

    2006-01-01

    Executive Summary Objective The objective of this review was to assess the safety and effectiveness of metal on metal (MOM) hip resurfacing arthroplasty for young patients compared with that of total hip replacement (THR) in the same population. Clinical Need Total hip replacement has proved to be very effective for late middle-aged and elderly patients with severe degenerative diseases of the hips. As indications for THR began to include younger patients and those with a more active life style, the longevity of the implant became a concern. Evidence suggests that these patients experience relatively higher rates of early implant failure and the need for revision. The Swedish hip registry, for example, has demonstrated a survival rate in excess of 80% at 20 years for those aged over 65 years, whereas this figure was 33% by 16 years in those aged under 55 years. Hip resurfacing arthroplasty is a bone-conserving alternative to THR that restores normal joint biomechanics and load transfer. The technique has been used around the world for more than 10 years, specifically in the United Kingdom and other European countries. The Technology Metal-on-metal hip resurfacing arthroplasty is an alternative procedure to conventional THR in younger patients. Hip resurfacing arthroplasty is less invasive than THR and addresses the problem of preserving femoral bone stock at the initial operation. This means that future hip revisions are possible with THR if the initial MOM arthroplasty becomes less effective with time in these younger patients. The procedure involves the removal and replacement of the surface of the femoral head with a hollow metal hemisphere, which fits into a metal acetabular cup. Hip resurfacing arthroplasty is a technically more demanding procedure than is conventional THR. In hip resurfacing, the femoral head is retained, which makes it much more difficult to access the acetabular cup. However, hip resurfacing arthroplasty has several advantages over a

  4. Ten-year results of a double-heat-treated metal-on-metal hip resurfacing.

    PubMed

    Daniel, J; Ziaee, H; Kamali, A; Pradhan, C; Band, T; McMinn, D J W

    2010-01-01

    Second-generation metal-on-metal bearings were introduced as a response to the considerable incidence of wear-induced failures associated with conventional replacements, especially in young patients. We present the results at ten years of a consecutive series of patients treated using a metal-on-metal hip resurfacing. A distinct feature of the bearings used in our series was that they had been subjected to double-heat treatments during the post-casting phase of their manufacture. In the past these bearings had not been subjected to thermal treatments, making this a unique metal-on-metal bearing which had not been used before in clinical practice. We report the outcome of 184 consecutive hips (160 patients) treated using a hybrid-fixed metal-on-metal hip resurfacing during 1996. Patients were invited for a clinicoradiological follow-up at a minimum of ten years. The Oxford hip score and anteroposterior and lateral radiographs were obtained. The mean age at operation was 54 years (21 to 75). A series of 107 consecutive hips (99 patients) who received the same prosthesis, but subjected to a single thermal treatment after being cast, between March 1994 and December 1995, were used as a control group for comparison. In the 1994 to 1995 group seven patients (seven hips) died from unrelated causes and there were four revisions (4%) for osteolysis and aseptic loosening. In the 1996 group nine patients died at a mean of 6.9 years after operation because of unrelated causes. There were 30 revisions (16%) at a mean of 7.3 years (1.2 to 10.9), one for infection at 1.2 years and 29 for osteolysis and aseptic loosening. Furthermore, in the latter group there were radiological signs of failure in 27 (24%) of the 111 surviving hips. The magnitude of the problem of osteolysis and aseptic loosening in the 1996 cohort did not become obvious until five years after the operation. Our results indicate that double-heat treatments of metal-on-metal bearings can lead to an increased

  5. ‘Pseudotumour’ invading the proximal femur with normal metal ions following metal on metal hip resurfacing

    PubMed Central

    Krishnan, Harry; Sugand, Kapil; Ali, Ibrahim; Smith, Jay

    2015-01-01

    A 75-year-old woman who had undergone hybrid metal-on-metal hip resurfacing 8 years earlier underwent revision arthroplasty because of hip, groin and lateral thigh pain. The main differential was aseptic loosening; however, serum cobalt and chromium levels were normal. Multiple imaging modalities revealed a periprosthetic, cystic soft tissue mass adjacent to the proximal femur. A large ‘pseudotumour’ with proximal femoral invasion was found at revision arthroplasty. We report the first finding of a ‘pseudotumour’ invading the proximal femur with normal metal ions following metal on metal hip resurfacing. PMID:25670783

  6. Asymptomatic pseudotumours after metal-on-metal hip resurfacing show little change within one year.

    PubMed

    van der Weegen, W; Brakel, K; Horn, R J; Hoekstra, H J; Sijbesma, T; Pilot, P; Nelissen, R G H H

    2013-12-01

    The aim of this study was to establish the natural course of unrevised asymptomatic pseudotumours after metal-on-metal (MoM) hip resurfacing during a six- to 12-month follow-up period. We used repeated metal artefact reduction sequence (MARS)-magnetic resonance imaging (MRI), serum metal ion analysis and clinical examination to study 14 unrevised hips (mean patient age 52.7 years, 46 to 68, 5 female, 7 male) with a pseudotumour and 23 hips (mean patient age 52.8 years, 38 to 69, 7 female, 16 male) without a pseudotumour. The mean post-operative time to the first MARS-MRI scan was 4.3 years (2.2 to 8.3), and mean time between the first and second MARS-MRI scan was eight months (6 to 12). At the second MRI scan, the grade of severity of the pseudotumour had not changed in 35 hips. One new pseudotumour (Anderson C2 score, moderate) was observed, and one pseudotumour was downgraded from C2 (moderate) to C1 (mild). In general, the characteristics of the pseudotumours hardly changed. Repeated MARS-MRI scans within one year in patients with asymptomatic pseudotumours after MoM hip resurfacing showed little or no variation. In 23 patients without pseudotumour, one new asymptomatic pseudotumour was detected. This is the first longitudinal study on the natural history of pseudotumours using MARS-MRI scans in hip resurfacing, and mirrors recent results for 28 mm diameter MoM total hip replacement.

  7. Microseparation, fluid pressure and flow in failures of metal-on-metal hip resurfacing arthroplasties

    PubMed Central

    Wroblewski, B. M.; Siney, P. D.; Fleming, P. A.

    2012-01-01

    Objectives Metal-on-metal (MoM) hip resurfacing was introduced into clinical practice because it was perceived to be a better alternative to conventional total hip replacement for young and active patients. However, an increasing number of reports of complications have arisen focusing on design and orientation of the components, the generation of metallic wear particles and serum levels of metallic ions. The procedure introduced a combination of two elements: large-dimension components and hard abrasive particles of metal wear. The objective of our study was to investigate the theory that microseparation of the articular surfaces draws in a high volume of bursal fluid and its contents into the articulation, and at relocation under load would generate high pressures of fluid ejection, resulting in an abrasive water jet. Methods This theoretical concept using MoM resurfacing components (head diameter 55 mm) was modelled mathematically and confirmed experimentally using a material-testing machine that pushed the head into the cup at a rate of 1000 mm/min until fully engaged. Results The mathematical model showed the pattern but not the force of fluid ejection, the highest pressures were expected when the separation of the components was only a fraction of one millimetre. The experimental work confirmed the results; with the mean peak ejection pressure of 43 763 N/m2 equivalent to 306 mmHg or 5 psi. Conclusions The mechanical effect of the high-pressure abrasive water jet is the likely cause of the spectrum of complications reported with metal-on-metal resurfacing. Investigating serum levels of metallic elements may not be the best method for assessing the local mechanical effects of the abrasive water jet. PMID:23610667

  8. Effect of simplifications of bone and components inclination on the elastohydrodynamic lubrication modeling of metal-on-metal hip resurfacing prosthesis.

    PubMed

    Meng, Qingen; Liu, Feng; Fisher, John; Jin, Zhongmin

    2013-05-01

    It is important to study the lubrication mechanism of metal-on-metal hip resurfacing prosthesis in order to understand its overall tribological performance, thereby minimize the wear particles. Previous elastohydrodynamic lubrication studies of metal-on-metal hip resurfacing prosthesis neglected the effects of the orientations of the cup and head. Simplified pelvic and femoral bone models were also adopted for the previous studies. These simplifications may lead to unrealistic predictions. For the first time, an elastohydrodynamic lubrication model was developed and solved for a full metal-on-metal hip resurfacing arthroplasty. The effects of the orientations of components and the realistic bones on the lubrication performance of metal-on-metal hip resurfacing prosthesis were investigated by comparing the full model with simplified models. It was found that the orientation of the head played a very important role in the prediction of pressure distributions and film profiles of the metal-on-metal hip resurfacing prosthesis. The inclination of the hemispherical cup up to 45° had no appreciable effect on the lubrication performance of the metal-on-metal hip resurfacing prosthesis. Moreover, the combined effect of material properties and structures of bones was negligible. Future studies should focus on higher inclination angles, smaller coverage angle and microseparation related to the occurrences of edge loading.

  9. Surface arthroplasty for osteonecrosis of the hip: hemiresurfacing versus metal-on-metal hybrid resurfacing.

    PubMed

    Beaulé, Paul E; Amstutz, Harlan C; Le Duff, Michel; Dorey, Frederic

    2004-12-01

    Eighty-four hips with Ficat stage III and IV osteonecrosis were treated: 56 with metal-on-metal surface arthroplasty (MMSA) and 28 with hemi-surface arthroplasty (HSA). Average follow-up was 4.9 years. UCLA hip scores were significantly better for MMSA versus HSA for function and activity as well as Harris Hip scores and physical component of the SF-12 scores. In the MMSA group, 2 hips were revised to total hip arthroplasty for femoral loosening, and 5 hips had adverse radiological changes. In the HSA group, 4 hips were revised (1 sepsis and 3 for pain). There was no evidence of any femoral loosening or neck narrowing in the HSA group. Although the functional clinical outcome of MMSA is superior to HSA, long-term follow up of MMSA will determine the reliability of the femoral fixation.

  10. Combined Vascular and Orthopaedic Approach for a Pseudotumor Causing Deep Vein Thrombosis after Metal-on-Metal Hip Resurfacing Arthroplasty.

    PubMed

    Abdel-Hamid, Hossam; Miles, Jonathan; Carrington, Richard W J; Hart, Alister; Loh, Alex; Skinner, John A

    2015-01-01

    Introduction. Metal-on-metal (MoM) hip resurfacings have been associated with a variety of complications resulting from adverse reaction to metal debris. Pseudotumors have rarely been reported to cause deep venous thrombosis (DVT). Study Design. A case report and a review of the literature. Case Presentation. A 75-year-old female who had left metal-on-metal hip resurfacing 6 years ago presented with left groin pain associated with unilateral lower limb edema and swelling. By duplex and MRI studies, our patient had an extensive soft tissue necrosis associated with a large pelvic mass causing extensive DVT of the lower limb secondary to mechanical compression of the left iliac vein. Results. Our case was initially treated for DVT followed by dual surgical approach. The pseudotumor was excised through a separate iliofemoral approach and revision of the hip implant was undertaken through a posterior approach in the same setting. An inferior vena cava (IVC) filter was inserted to minimise the perioperative risks of handling the iliac veins. Conclusion. A combined approach with vascular surgeons is required. Combined resection of the pseudotumor and revision of the metal bearing surfaces is essential, in order to achieve a good surgical outcome in this rare complication.

  11. Influence of the clearance on in-vitro tribology of large diameter metal-on-metal articulations pertaining to resurfacing hip implants.

    PubMed

    Rieker, Claude B; Schön, Rolf; Konrad, Reto; Liebentritt, Gernot; Gnepf, Patric; Shen, Ming; Roberts, Paul; Grigoris, Peter

    2005-04-01

    Large-diameter metal-on-metal articulations may provide an opportunity for wear reduction in total hip implants because earlier studies have shown that the formation of a fluid film that completely separates the bearing surfaces is theoretically possible. In such a lubrication mode and under ideal conditions, there is theoretically no amount of wear. Studies have suggested that the two primary parameters controlling the lubrication mode are the diameter and the clearance of the articulation. The goal of the present study was to experimentally investigate the influence of these two parameters on the wear behavior of large-diameter metal-on-metal articulations pertaining to resurfacing hip implants. The results of this in vitro investigation showed that longer running-in periods and higher amounts of running-in wear were associated with larger clearances.

  12. Which imaging modality is most effective for identifying pseudotumours in metal-on-metal hip resurfacings requiring revision

    PubMed Central

    Matharu, G. S.; Mansour, R.; Dada, O.; Ostlere, S.; Pandit, H. G.; Murray, D. W.

    2016-01-01

    Aims The aims of this study were to compare the diagnostic test characteristics of ultrasound alone, metal artefact reduction sequence MRI (MARS-MRI) alone, and ultrasound combined with MARS-MRI for identifying intra-operative pseudotumours in metal-on-metal hip resurfacing (MoMHR) patients undergoing revision surgery. Methods This retrospective diagnostic accuracy study involved 39 patients (40 MoMHRs). The time between imaging modalities was a mean of 14.6 days (0 to 90), with imaging performed at a mean of 5.3 months (0.06 to 12) before revision. The prevalence of intra-operative pseudotumours was 82.5% (n = 33). Results Agreement with the intra-operative findings was 82.5% (n = 33) for ultrasound alone, 87.5% (n = 35) for MARS-MRI alone, and 92.5% (n = 37) for ultrasound and MARS-MRI combined. The diagnostic characteristics for ultrasound alone and MARS-MRI alone reached similar sensitivities (90.9% vs 93.9%) and positive predictive values (PPVs; 88.2% vs 91.2%), but higher specificities (57.1% vs 42.9%) and negative predictive values (NPVs; 66.7% vs 50.0%) were achieved with MARS-MRI. Ultrasound and MARS-MRI combined produced 100% sensitivity and 100% NPV, whilst maintaining both specificity (57.1%) and PPV (91.7%). For the identification of a pseudotumour, which was confirmed at revision surgery, agreement was substantial for ultrasound and MARS-MRI combined (κ = 0.69), moderate for MARS-MRI alone (κ = 0.54), and fair for ultrasound alone (κ = 0.36). Discussion These findings suggest that ultrasound and/or MARS-MRI have a role when assessing patients with a MoMHR, with the choice dependent on local financial constraints and the availability of ultrasound expertise. However in patients with a MoMHR who require revision, combined imaging was most effective. Take home message: Combined imaging with ultrasound and MARS-MRI always identified intra-operative pseudotumours if present. Furthermore, if neither imaging modality showed a pseudotumour, one was not

  13. The effect of 'running-in' on the tribology and surface morphology of metal-on-metal Birmingham hip resurfacing device in simulator studies.

    PubMed

    Vassiliou, K; Elfick, A P D; Scholes, S C; Unsworth, A

    2006-02-01

    It is well documented that hard bearing combinations show a running-in phenomenon in vitro and there is also some evidence of this from retrieval studies. In order to investigate this phenomenon, five Birmingham hip resurfacing devices were tested in a hip wear simulator. One of these (joint 1) was also tested in a friction simulator before, during, and after the wear test and surface analysis was conducted throughout portions of the testing. The wear showed the classical running in with the wear rate falling from 1.84 mm3 per 10(6) cycles for the first 10(6) cycles of testing to 0.24 mm3 per 10(6) cycles over the final 2 x 10(6) cycles of testing. The friction tests suggested boundary lubrication initially, but at 1 x 10(6) cycles a mixed lubrication regime was evident. By 2 x 10(6) cycles the classical Stribeck curve had formed, indicating a considerable contribution from the fluid film at higher viscosities. This continued to be evident at both 3 x 10(6) and 5 x 10(6) cycles. The surface study complements these findings.

  14. Metal-on-metal hip joint tribology.

    PubMed

    Dowson, D; Jin, Z M

    2006-02-01

    The basic tribological features of metal-on-metal total hip replacements have been reviewed to facilitate an understanding of the engineering science underpinning the renaissance of these hard-on-hard joints. Metal-on-polymer hip replacements operate in the boundary lubrication regime, thus leading to the design guidance to reduce the femoral head diameter as much as is feasible to minimize frictional torque and volumetric wear. This explains why the gold-standard implant of this form from the past half-century had a diameter of only 22.225 mm (7/8 in). Metal-on-metal implants can operate in the mild mixed lubrication regime in which much of the applied load is supported by elastohydrodynamic films. Correct tribological design leads to remarkably low steady state wear rates. Promotion of the most effective elastohydrodynamic films calls for the largest possible head diameters and the smallest clearances that can reasonably be adopted, consistent with fine surface finishes, good sphericity and minimal structural elastic deformation of the cup on its foundations. This guidance, which is opposite in form to that developed for metal-on-polymer joints, is equally valid for solid (monolithic) metallic heads on metallic femoral stems and surface replacement femoral shells. Laboratory measurements of friction and wear in metal-on-metal joints have confirmed their potential to achieve a very mild form of mixed lubrication. The key lies in the generation of effective elastohydrodynamic lubricating films of adequate thickness compared with the composite roughness of the head and cup. The calculation of the film thickness is by no means easy, but the full procedure is outlined and the use of an empirical formula that displays good agreement with calculations based upon the full numerical solutions is explained. The representation of the lambda ratio, lambda, embracing both film thickness and composite roughness, is described.

  15. [Resurfacing arthroplasty of the hip].

    PubMed

    Knecht, A; Witzleb, W-C; Günther, K-P

    2005-01-01

    Currently, an increase in resurfacing arthroplasty in the treatment of hip osteoarthritis--especially in young adults--can be observed. New bearing technologies (mainly metal-on-metal surfaces) show better tribologic results than historical designs (e.g. the Wagner cup). At present, it is unclear whether these modifications and a definitively low dislocation rate--due to the large head diameter--can be supported by further good clinical results. The quantity as well as the quality of the available investigations prevents a definite opinion at the moment. Appropriate clinical studies with documented radiographic follow-up are necessary to compare the outcome of these new implants with standard techniques.

  16. Breast milk metal ion levels in a young and active patient with a metal-on-metal hip prosthesis.

    PubMed

    Nelis, Raymond; de Waal Malefijt, Jan; Gosens, Taco

    2013-01-01

    Metal-on-metal resurfacing arthroplasty of the hip has been used increasingly over the last 10 years in younger active patients. The dissolution of the metal wear particles results in measurable increases in cobalt and chromium ions in the serum and urine of patients with a metal-on-metal bearing. We measured the cobalt, chromium, and molybdenum ion levels in urine; serum; and breast milk in a young and active patient with a metal-on-metal hip prosthesis after a pathologic fracture of the femoral neck. Metal-on-metal hip prosthesis leads to increasing levels of molybdenum in breast milk in the short-term follow-up. There are no increasing levels of chromium and cobalt ions in breast milk. Besides the already known elevated concentrations in serum of chromium and cobalt after implantation of a metal-on-metal hip prosthesis, we found no increasing levels of chromium and cobalt in urine.

  17. Three metal-on-metal hip replacement devices from the same manufacturer--a short- to mid-term survival.

    PubMed

    Kostensalo, Inari; Junnila, Mika; Mokka, Jari; Virolainen, Petri; Vahlberg, Tero; Mäkelä, Keijo T

    2014-06-01

    The aim of this retrospective study was to evaluate short- to mid-term results of three different metal-on-metal hip devices from the same manufacturer. A total of 329 hip operations were performed in a single academic unit between 2004 and 2010 using either Birmingham hip resurfacing or Synergy--Birmingham and Synergy--R3 total hip arthroplasty. The overall survival rate at the end of the follow-up time for Birmingham hip resurfacing was 88%, for Synergy--Birmingham total hip arthroplasty 95%, and for Synergy--R3 total hip arthroplasty 81% (p = 0.036). Five revision operations were performed due to adverse reaction to metal debris. Head sizes > 50 mm had lower revision rates compared to smaller ones. Synergy--R3 had a poor survival already at short-term. The mid-term survival of Birmingham hip resurfacing arthroplasty was inferior compared to previous studies.

  18. Information for Patients Who Have Metal-on-Metal Hip Implants

    MedlinePlus

    ... Metal Hip Implants Information for Patients Who Have Metal-on-Metal Hip Implants Share Tweet Linkedin Pin it More ... How do I know if I have a metal-on-metal hip implant? Patients are usually told ...

  19. The tribology of metal-on-metal total hip replacements.

    PubMed

    Scholes, S C; Unsworth, A

    2006-02-01

    Total hip surgery is an effective way of alleviating the pain and discomfort caused by diseased or damaged joints. However, in the majority of cases, these joints have a finite life. The main reason for failure is osteolysis (bone resorption). It is well documented that an important cause of osteolysis, and therefore the subsequent loosening and failure of conventional metal- or ceramic-on-ultra-high molecular weight polyethylene joints, is the body's immunological response to the polyethylene wear particles. To avoid this, interest has been renewed in metal-on-metal joints. The intention of this paper is to review the studies that have taken place within different laboratories to determine the tribological performance of new-generation metal-on-metal total hip replacements. These types of joint offer a potential solution to enhance the longevity of prosthetic hip systems; however, problems may arise owing to the effects of metal ion release, which are, as yet, not fully understood.

  20. CoCrMo Metal-on-Metal Hip Replacements

    PubMed Central

    Liao, Yifeng; Hoffman, Emily; Wimmer, Markus; Fischer, Alfons; Jacobs, Joshua; Marks, Laurence

    2012-01-01

    After the rapid growth in the use of CoCrMo metal-on-metal hip replacements since the second generation was introduced circa 1990, metal-on-metal hip replacements have experienced a sharp decline in the last two years due to biocompatibility issues related to wear and corrosion products. Despite some excellent clinical results, the release of wear and corrosion debris and the adverse response of local tissues have been of great concern. There are many unknowns regarding how CoCrMo metal bearings interact with the human body. This perspective article is intended to outline some recent progresses in understanding wear and corrosion of metal-on-metal hip replacement both in-vivo and in-vitro. The materials, mechanical deformation, corrosion, wear-assisted corrosion, and wear products will be discussed. Possible adverse health effects caused by wear products will be briefly addressed, as well as some of the many open questions such as the detailed chemistry of corrosion, tribochemical reactions and the formation of graphitic layers. Nowadays we design almost routinely for high performance materials and lubricants for automobiles; humans are at least as important. It is worth remembering that a hip implant is often the difference between walking and leading a relatively normal life, and a wheelchair. PMID:23196425

  1. Graphitic Tribological Layers in Metal-on-Metal Hip Replacements

    NASA Astrophysics Data System (ADS)

    Liao, Y.; Pourzal, R.; Wimmer, M. A.; Jacobs, J. J.; Fischer, A.; Marks, L. D.

    2011-12-01

    Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical role and that there is a tribological layer on the metal surface. We report evidence for graphitic material in the tribological layer in metal-on-metal hip replacements retrieved from patients. As graphite is a solid lubricant, its presence helps to explain why these components exhibit low wear and suggests methods of improving their performance; simultaneously, this raises the issue of the physiological effects of graphitic wear debris.

  2. Muscle atrophy and metal-on-metal hip implants

    PubMed Central

    Berber, Reshid; Khoo, Michael; Cook, Erica; Guppy, Andrew; Hua, Jia; Miles, Jonathan; Carrington, Richard; Skinner, John; Hart, Alister

    2015-01-01

    Background and purpose Muscle atrophy is seen in patients with metal-on-metal (MOM) hip implants, probably because of inflammatory destruction of the musculo-tendon junction. However, like pseudotumors, it is unclear when atrophy occurs and whether it progresses with time. Our objective was to determine whether muscle atrophy associated with MOM hip implants progresses with time. Patients and methods We retrospectively reviewed 74 hips in 56 patients (32 of them women) using serial MRI. Median age was 59 (23–83) years. The median time post-implantation was 83 (35–142) months, and the median interval between scans was 11 months. Hip muscles were scored using the Pfirrmann system. The mean scores for muscle atrophy were compared between the first and second MRI scans. Blood cobalt and chromium concentrations were determined. Results The median blood cobalt was 6.84 (0.24–90) ppb and median chromium level was 4.42 (0.20–45) ppb. The median Oxford hip score was 34 (5–48). The change in the gluteus minimus mean atrophy score between first and second MRI was 0.12 (p = 0.002). Mean change in the gluteus medius posterior portion (unaffected by surgical approach) was 0.08 (p = 0.01) and mean change in the inferior portion was 0.10 (p = 0.05). Mean pseudotumor grade increased by 0.18 (p = 0.02). Interpretation Worsening muscle atrophy and worsening pseudotumor grade occur over a 1-year period in a substantial proportion of patients with MOM hip implants. Serial MRI helps to identify those patients who are at risk of developing worsening soft-tissue pathology. These patients should be considered for revision surgery before irreversible muscle destruction occurs. PMID:25588091

  3. Hip resurfacing arthroplasty complicated by mismatched implant components

    PubMed Central

    Calistri, Alessandro; Campbell, Patricia; Van Der Straeten, Catherine; De Smet, Koen Aimè

    2017-01-01

    Metal-on-metal hip resurfacing has gained popularity as a feasible treatment option for young and active patients with hip osteoarthritis and high functional expectations. This procedure should only be performed by surgeons who have trained specifically in this technique. Preoperative planning is essential for hip resurfacing in order to execute a successful operation and preview any technical problems. The authors present a case of a man who underwent a resurfacing arthroplasty for osteoarthritis of the left hip that was complicated by mismatched implant components that were revised three days afterwards for severe pain and leg length discrepancy. Such mistakes, although rare, can be prevented by educating operating room staff in the size and colour code tables provided by the companies on their prostheses or implant boxes. PMID:28361022

  4. Metal on metal surface replacement of the hip. Experience of the McMinn prothesis.

    PubMed

    McMinn, D; Treacy, R; Lin, K; Pynsent, P

    1996-08-01

    The historical failure of surface replacement has been due to the production of wear debris with subsequent bone resorption, loosening, and failure. To avoid these problems, a surface replacement using a metal on metal bearing allowing thin components and femoral design and instrumentation to avoid varus alignment has been designed. Two hundred thirty-five joints have been resurfaced with this prosthesis in almost 5 years. There have been no femoral neck fractures and no dislocations. There have been 4 designs differing in the method of fixation. In the press fit group, 6 of 70 hips had to be revised for aseptic loosening. In the cemented group, debonding of the cup occurred in 3 of 43 cases. Six patients had hydroxyapatite coated components and have had excellent clinical outcomes. The current design uses a peripherally expanded hydroxyapatite coated cup and a cemented metal head; 116 of this design have been implanted during a 19-month period with excellent outcome. Despite short followup the authors are hopeful that the combination of a polar metal on metal bearing with appropriate fixation will yield a method of preserving bone stock in the younger patient requiring arthroplasty.

  5. Explant analysis of the Biomet Magnum/ReCap metal-on-metal hip joint

    PubMed Central

    Hunt, B. J.; Richardson, V. M.; Langton, D. J.; Smith, E.; Joyce, T. J.

    2017-01-01

    Objectives The high revision rates of the DePuy Articular Surface Replacement (ASR) and the DePuy ASR XL (the total hip arthroplasty (THA) version) have led to questions over the viability of metal-on-metal (MoM) hip joints. Some designs of MoM hip joint do, however, have reasonable mid-term performance when implanted in appropriate patients. Investigations into the reasons for implant failure are important to offer help with the choice of implants and direction for future implant designs. One way to assess the performance of explanted hip prostheses is to measure the wear (in terms of material loss) on the joint surfaces. Methods In this study, a coordinate measuring machine (CMM) was used to measure the wear on five failed cementless Biomet Magnum/ReCap/ Taperloc large head MoM THAs, along with one Biomet ReCap resurfacing joint. Surface roughness measurements were also taken. The reason for revision of these implants was pain and/or adverse reaction to metal debris (ARMD) and/or elevated blood metal ion levels. Results The mean wear rate of the articulating surfaces of the heads and acetabular components of all six joints tested was found to be 6.1 mm3/year (4.1 to 7.6). The mean wear rate of the femoral head tapers of the five THAs was 0.054 mm3/year (0.021 to 0.128) with a mean maximum wear depth of 5.7 µm (4.3 to 8.5). Conclusion Although the taper wear was relatively low, the wear from the articulating surfaces was sufficient to provide concern and was potentially large enough to have been the cause of failure of these joints. The authors believe that patients implanted with the ReCap system, whether the resurfacing prosthesis or the THA, should be closely monitored. Cite this article: S. C. Scholes, B. J. Hunt, V. M. Richardson, D. J. Langton, E. Smith, T. J. Joyce. Explant analysis of the Biomet Magnum/ReCap metal-on-metal hip joint. Bone Joint Res 2017;6:113–122. DOI: 10.1302/2046-3758.62.BJR-2016-0130.R2. PMID:28246095

  6. Lessons learnt from metal-on-metal hip arthroplasties will lead to safer innovation for all medical devices.

    PubMed

    Hart, Alister J; Sabah, Shiraz A; Henckel, Johann; Lloyd, Gwynneth; Skinner, John A

    2015-01-01

    Metal-on-metal bearings were re-popularised in the late 1990s with the introduction of modern hip resurfacing. Large diameter (LD) metal-on-metal (MoM) hips became more prevalent and have been the least successful group of hip implants ever used. They were rapidly adopted from 2004 until the British Hip Society stopped their use in 2012. Well functioning MoM hip results (including the BHR and Metasul) are hidden in the mire of poor results from the group of all MoM bearings.We have reviewed what happened and we make 3 observations. Firstly, collaboration between surgeons and then between surgeons and other disciplines, first identified and then solved the clinical management problems. Secondly, the problems with MoM hips occurred because hip simulation was inadequate at predicting performance in patients. They gave no indications of the biological effects of wear in the human environment. Lastly, retrieval of failed implants was essential to understanding why failure occurred.These lessons must never be forgotten and must form the basis by which new or altered implants are introduced and how they should be monitored. This will enable safer innovation for patients, surgeons and manufacturers. The problems with MoM hips will not have been in vain.

  7. Heart failure after conventional metal-on-metal hip replacements

    PubMed Central

    Gillam, Marianne H; Pratt, Nicole L; Inacio, Maria C S; Roughead, Elizabeth E; Shakib, Sepehr; Nicholls, Stephen J; Graves, Stephen E

    2017-01-01

    Background and purpose — It is unclear whether metal particles and ions produced by mechanical wear and corrosion of hip prostheses with metal-on-metal (MoM) bearings have systemic adverse effects on health. We compared the risk of heart failure in patients with conventional MoM total hip arthroplasty (THA) and in those with metal-on-polyethylene (MoP) THA. Patients and methods — We conducted a retrospective cohort study using data from the Australian Government Department of Veterans’ Affairs health claims database on patients who received conventional THA for osteoarthritis between 2004 and 2012. The MoM THAs were classified into groups: Articular Surface Replacement (ASR) XL Acetabular System, other large-head (LH) (> 32 mm) MoM, and small-head (SH) (≤ 32 mm) MoM. The primary outcome was hospitalization for heart failure after THA. Results — 4,019 patients with no history of heart failure were included (56% women). Men with an ASR XL THA had a higher rate of hospitalization for heart failure than men with MoP THA (hazard ratio (HR) = 3.2, 95% CI: 1.6–6.5). No statistically significant difference in the rate of heart failure was found with the other LH MoM or SH MoM compared to MoP in men. There was no statistically significant difference in heart failure rate between exposure groups in women. Interpretation — An association between ASR XL and hospitalization for heart failure was found in men. While causality between ASR XL and heart failure could not be established in this study, it highlights an urgent need for further studies to investigate the possibility of systemic effects associated with MoM THA. PMID:27759468

  8. Balancing innovation and medical device regulation: the case of modern metal-on-metal hip replacements

    PubMed Central

    Howard, Jason J

    2016-01-01

    Due to problems with wear particle generation and subsequent loosening using conventional metal-on-polyethylene total hip replacements, there has been a shift toward alternative bearing systems, including metal-on-metal (MoM), for younger, more active patients with degenerative joint disease. Based on positive results from early short-term clinical studies, MoM hip replacements were readily adopted by orthopedic surgeons with thousands being implanted worldwide over the past decade. Unacceptably high revision rates reported by two national joint registries called into question the rigorousness of the regulatory approval process for these implants, particularly with respect to premarket data requirements to prove safety, effectiveness, and the appropriateness of the regulatory pathway chosen. The purpose of this review was to investigate the balance between facilitating the introduction of new medical technologies and the need to ensure safety and effectiveness through comprehensive regulatory assessment. The case of MoM hip replacement devices was used to frame the investigation and subsequent discussions. The regulatory approval processes and post-market surveillance requirements associated with three common MoM hip replacements (two resurfacings: the Birmingham and articular surface replacement and the articular surface replacement XL total hip replacement) were investigated. With respect to modern MoM hip replacement devices, the balance between facilitating the introduction of these new medical technologies and the need to ensure safety and effectiveness through comprehensive regulatory assessment was not achieved. The lessons learned from these experiences have application beyond joint replacements to the introduction of new medical technologies in general, particularly for those who have a significant potential for harm. In this regard, a series of recommendations have been developed to contribute to the evolution of the medical device regulatory process

  9. Blood levels of cobalt and chromium are inversely correlated to head size after metal-on-metal resurfacing arthroplasty.

    PubMed

    Parry, Michael C; Eastaugh-Waring, Steve; Bannister, Gordon C; Learmonth, Ian D; Case, Charles Patrick; Blom, Ashley W

    2013-01-01

    Resurfacing arthroplasty has fallen out of favour in recent years due to unfavourable survivorship in joint registries and alarming reports of soft tissue reactions around metal on metal prostheses. Our aim was to assess the effect of head size, implant design and component positioning on metal production by resurfacing arthroplasties. We measured whole blood cobalt and chromium and component position in matched populations implanted with two designs of resurfacing arthroplasty over a two-year period. Both implants resulted in a significant increase in blood metal levels (p<0.001) though the ASR design generated significantly higher metal levels (p = 0.041). A significant inverse correlation was seen between component size and blood cobalt levels (p = 0.032) and blood chromium levels (p<0.001). No correlation was identified between component position and blood metal levels. Small diameter metal resurfacing components result in increased metal generation compared with larger components. As increased metal generation has been correlated to wear and therefore failure, caution must be used on implantation of smaller components and indeed, in those who require smaller components, alternative bearing materials should be considered. These results contrast with recent findings which have demonstrated early failure for larger diameter stemmed metal-on-metal prostheses.

  10. Mechanical failure of metal-polyethylene sandwich liner in metal-on-metal total hip replacement.

    PubMed

    Oshima, Yasushi; Fetto, Joseph F

    2015-01-01

    Metal-on-metal had been proposed as an optimal articulation in THRs, however, many monoblock prostheses have been recalled in the USA because of significant high rates of early failure. Metal-on-metal prostheses had been implanted in our institution, and this is a case history of a single patient, in whom metal-on-metal THRs with different femoral sizes of heads were implanted. A 57-year-old female patient underwent bilateral total hip replacements with metal-on-metal prostheses using metal-polyethylene "sandwich" liners 9 years ago on the right side and 7 years ago on the left side respectively. The only difference in both sides was the femoral head diameter of 28 mm in right and 34 mm in left. Seven years after the left surgery, the acetabular liner was dissociated, however, metallosis was not detected. Although the larger femoral head was thought to increase hip joint stability, it dictated a reduction in polyethylene thickness in this prosthesis design, and it was 4 mm in the left hip. Recently, metal-on-metal articulations are thought not to be optimal for hip joint bearing surface, however, this clinical failure was due to the polyethylene thickness and quality.

  11. Hip resurfacing arthroplasty: mid-term results in 486 cases and current indication in our institution.

    PubMed

    Ribas, Manuel; Cardenas, Carlomagno; Astarita, Emanuele; Moya, Esther; Bellotti, Vittorio

    2014-10-02

    In the previous decade, metal-on-metal hip resurfacing has been considered an attractive option and theoretically advantageous over conventional total hip arthroplasty, especially in young active patients. Different authors have reported favourable mid-term clinical and functional results with acceptable survival rates. Proper indication and planning, as accurate technical execution have been advocated to be crucial elements for success.Concerns regarding serum metal ion levels and possible clinical implications have led in the last years to a decline in the use of metal-on-metal hip resurfacing and metal-on-metal bearings in general.The aim of this study is to present the results of our first 486 cases of hybrid hip resurfacing arthroplasties with a second generation cementing technique, and to describe our current restricted indication of this type of prosthesis, in the light of recent findings in the literature about the possible complications related to metallosis or improper patient selection. Global survivorship of our series was 97.9% at a mean follow-up of 7.2 years.In the second season of our experience the indication is restrictive. The candidate for a resurfacing hip replacement is a young and active male patient, with good bone quality, that has been made aware of the risks and benefits of this type of prosthesis.

  12. Has Metal-On-Metal Resurfacing Been a Cost-Effective Intervention for Health Care Providers?—A Registry Based Study

    PubMed Central

    Pulikottil-Jacob, Ruth; Connock, Martin; Kandala, Ngianga-Bakwin; Mistry, Hema; Grove, Amy; Freeman, Karoline; Costa, Matthew; Sutcliffe, Paul; Clarke, Aileen

    2016-01-01

    Background Total hip replacement for end stage arthritis of the hip is currently the most common elective surgical procedure. In 2007 about 7.5% of UK implants were metal-on-metal joint resurfacing (MoM RS) procedures. Due to poor revision performance and concerns about metal debris, the use of RS had declined by 2012 to about a 1% share of UK hip procedures. This study estimated the lifetime cost-effectiveness of metal-on-metal resurfacing (RS) procedures versus commonly employed total hip replacement (THR) methods. Methodology/Principal Findings We performed a cost-utility analysis using a well-established multi-state semi-Markov model from an NHS and personal and social services perspective. We used individual patient data (IPD) from the National Joint Registry (NJR) for England and Wales on RS and THR surgery for osteoarthritis recorded from April 2003 to December 2012. We used flexible parametric modelling of NJR RS data to guide identification of patient subgroups and RS devices which delivered revision rates within the NICE 5% revision rate benchmark at 10 years. RS procedures overall have an estimated revision rate of 13% at 10 years, compared to <4% for most THR devices. New NICE guidance now recommends a revision rate benchmark of <5% at 10 years. 60% of RS implants in men and 2% in women were predicted to be within the revision benchmark. RS devices satisfying the 5% benchmark were unlikely to be cost-effective compared to THR at a standard UK willingness to pay of £20,000 per quality-adjusted life-year. However, the probability of cost effectiveness was sensitive to small changes in the costs of devices or in quality of life or revision rate estimates. Conclusion/Significance Our results imply that in most cases RS has not been a cost-effective resource and should probably not be adopted by decision makers concerned with the cost effectiveness of hip replacement, or by patients concerned about the likelihood of revision, regardless of patient age or

  13. Transplacental transfer of cobalt and chromium in patients with metal-on-metal hip arthroplasty: a controlled study.

    PubMed

    Ziaee, H; Daniel, J; Datta, A K; Blunt, S; McMinn, D J W

    2007-03-01

    Metal-on-metal bearings are being increasingly used in young patients. The potential adverse effects of systemic metal ion elevation are the subject of ongoing investigation. The purpose of this study was to investigate whether cobalt and chromium ions cross the placenta of pregnant women with a metal-on-metal hip resurfacing and reach the developing fetus. Whole blood levels were estimated using high-resolution inductively-coupled plasma mass spectrometry. Our findings showed that cobalt and chromium are able to cross the placenta in the study patients with metal-on-metal hip resurfacings and in control subjects without any metal implants. In the study group the mean concentrations of cobalt and chromium in the maternal blood were 1.39 microg/l (0.55 to 2.55) and 1.28 microg/l (0.52 to 2.39), respectively. The mean umbilical cord blood concentrations of cobalt and chromium were comparatively lower, at 0.839 microg/l (0.42 to 1.75) and 0.378 microg/l (0.14 to 1.03), respectively, and this difference was significant with respect to chromium (p < 0.05). In the control group, the mean concentrations of cobalt and chromium in the maternal blood were 0.341 microg/l (0.18 to 0.54) and 0.199 microg/l (0.12 to 0.33), and in the umbilical cord blood they were 0.336 microg/l (0.17 to 0.5) and 0.194 microg/l (0.11 to 0.56), respectively. The differences between the maternal and umbilical cord blood levels in the controls were marginal, and not statistically significant (p > 0.05). The mean cord blood level of cobalt in the study patients was significantly greater than that in the control group (p < 0.01). Although the mean umbilical cord blood chromium level was nearly twice as high in the study patients (0.378 microg/l) as in the controls (0.1934 microg/l), this difference was not statistically significant. (p > 0.05) The transplacental transfer rate was in excess of 95% in the controls for both metals, but only 29% for chromium and 60% for cobalt in study patients

  14. Recall of the ASR XL Head and Hip Resurfacing Systems.

    PubMed

    Maurer-Ertl, Werner; Friesenbichler, Joerg; Holzer, Lukas A; Leitner, Lukas; Ogris, Kathrin; Maier, Michael; Leithner, Andreas

    2016-12-19

    At the beginning of the 21st century, use of large-diameter, metal-on-metal devices was a popular procedure for hip replacement in young and physically active patients; however, within a few years, the number of revisions increased, resulting in a worldwide recall for the articular surface replacement (ASR) system. Complication rates for the ASR devices implanted at the authors' department are reported, with revision rates of 32% and 30% in the ASR XL Head and ASR Resurfacing groups, respectively. Reasons for revision surgery were serum metal ion elevation, luxation or subluxation, aseptic loosening, soft tissue compromise (adverse reactions to metal debris [ARMD]), and infection. The calculated implant survival for the ASR XL Head system and the ASR Resurfacing device (DePuy Orthopaedics Inc, Warsaw, Indiana) in the current series was 79% and 90%, respectively, at 60 months. Symptomatic patients with metal-on-metal devices, with or without elevated metal ion concentrations, should undergo cross sectional imaging to exclude ARMD. In cases of increased metal ion concentrations, local pain, or ARMD, revision surgery has to be evaluated. In the future, closer monitoring of new implants is needed to prevent high failure rates, as seen with the ASR design. Furthermore, the withdrawal of the device highlights the importance of national implant registries. [Orthopedics. 201x; xx(x):xx-xx.].

  15. Increased Mortality in Metal-on-Metal versus Non-Metal-on-Metal Primary Total Hip Arthroplasty at 10 Years and Longer Follow-Up: A Systematic Review and Meta-Analysis

    PubMed Central

    Meessen, J. M. T. A.; Fiocco, M.; van der Heide, H. J. L.; Sedrakyan, A.; Nelissen, R. G. H. H.

    2016-01-01

    Importance There are concerns about increased mortality in patients with metal-on-metal bearings in total hip arthroplasty (THA). Objective To determine the mortality and the morbidity in patients with metal-on-metal articulations (MOM THA) compared to patients with non-metal-on-metal articulations (non-MOM THA) after primary total hip arthroplasty. Data Sources Search of PubMed, MEDLINE, EMBASE, Web of Science, Cochrane, CINAHL, AcademicSearchPremier, ScienceDirect, Wiley and clinical trial registers through March 2015, augmented by a hand search of references from the included articles. No language restrictions were applied. Study Selection Two reviewers screened and identified randomised controlled trials and observational studies of primary total hip arthroplasty comparing MOM THA with non-MOM THA. Data Extraction and Synthesis Two reviewers independently extracted study data and assessed risk of bias. Risk differences (RD) were calculated with random effect models. Meta-regression was used to explore modifying factors. Main Outcomes and Measures Difference in mortality and difference in morbidity expressed as revisions and medical complications between patients with MOM THA and non-MOM THA. Results Forty-seven studies were included, comprising 4,000 THA in randomised trials and over 500,000 THA in observational studies. For mortality, random effects analysis revealed a higher pooled RD of 0.7%, 95%, confidence interval (CI) [0.0%, 2.3%], I-square 42%; the heterogeneity was explained by differences in follow-up. When restricted to studies with long term follow-up (i.e. 10 years or more), the RD for mortality was 8.5%, 95%, CI [5.8%, 11.2%]; number needed to treat was 12. Further subgroup analyses and meta-regression random effects models revealed no evidence for other moderator variables (study level covariates, e.g. resurfacing vs. non-resurfacing MOM) than follow-up duration. The quality of the evidence presented in this meta-analysis was characterized as

  16. Lubrication and friction prediction in metal-on-metal hip implants.

    PubMed

    Wang, F C; Brockett, C; Williams, S; Udofia, I; Fisher, J; Jin, Z M

    2008-03-07

    A general methodology of mixed lubrication analysis and friction prediction for a conforming spherical bearing in hip implants was developed, with particular reference to a typical metal-on-metal hip replacement. Experimental measurement of frictional torque for a similar implant was carried out to validate the theoretical prediction. A ball-in-socket configuration was adopted to represent the articulation between the femoral head and the acetabular cup under cyclic operating conditions of representative load and motion. The mixed lubrication model presented in this study was first applied to identify the contact characteristics on the bearing surfaces, consisting of both fluid-film and boundary lubricated regions. The boundary lubricated contact was assumed to occur when the predicted fluid film thickness was less than a typical boundary protein layer absorbed on the bearing surfaces. Subsequently, the friction was predicted from the fluid-film lubricated region with viscous shearing due to both Couette and Poiseuille flows and the boundary protein layer contact region with a constant coefficient of friction. The predicted frictional torque of the typical metal-on-metal hip joint implant was compared with the experimental measurement conducted in a functional hip simulator and a reasonably good agreement was found. The mixed lubrication regime was found to be dominant for the conditions considered. Although the percentage of the boundary lubricated region was quite small, the corresponding contribution to friction was quite large and the resultant friction factor was quite high.

  17. Effect of ion implantation on the tribology of metal-on-metal hip prostheses.

    PubMed

    Bowsher, John G; Hussain, Azad; Williams, Paul; Nevelos, Jim; Shelton, Julia C

    2004-12-01

    Nitrogen ion implantation (which considerably hardens the surface of the bearing) may represent one possible method of reducing the wear of metal-on-metal (MOM) hip bearings. Currently there are no ion-implanted MOM bearings used clinically. Therefore a physiological hip simulator test was undertaken using standard test conditions, and the results compared to previous studies using the same methods. N2-ion implantation of high carbon cast Co-Cr-Mo-on-Co-Cr-Mo hip prostheses increased wear by 2-fold during the aggressive running-in phase compared to untreated bearing surfaces, plus showing no wear reductions during steady-state conditions. Although 2 specimens were considered in the current study, it would appear that ion implantation has no clinical benefit for MOM.

  18. High Re-Operation Rates Using Conserve Metal-On-Metal Total Hip Articulations

    PubMed Central

    Mogensen, S.L.; Jakobsen, T.; Christoffersen, H.; Krarup, N.

    2016-01-01

    Introduction: Metal-on-metal hip articulations have been intensely debated after reports of adverse reactions and high failure rates. The aim of this study was to retrospectively evaluate the implant of a metal-on.metal total hip articulation (MOM THA) from a single manufacture in a two-center study. Materials and Methods: 108 CONSERVE® MOM THA were implanted in 92 patients between November 2005 and December 2010. Patients had at time of retrospective evaluation their journals reviewed for re-operations and adverse reactions. Results: 20 hips were re-operated (18.4%) at a mean follow up of 53 months. 4 pseudotumors were diagnosed at time of follow up but no substantiated link was made between adverse reactions and re-operations. Conclusion: The high re-operation rates found in this study raised concern about the usage of the MOM THA and subsequently lead to the termination of implantation of this MOM THA at the two orthopaedic departments. PMID:27099640

  19. Large diameter metal on metal total hip replacement for femoral neck fractures with neurological conditions

    PubMed Central

    Li, Jia; Zheng, Wei; Zhao, Jinzhu; Liu, Denghui; Xu, Weidong

    2014-01-01

    Background: Patients with Parkinson's disease and poliomyelitis can have a femoral neck fracture; yet, the optimal methods of treatment for these hips remains controversial. Many constrained or semi-constrained prostheses, using constrained liners (CLs) with a locking mechanism to capture the femoral head, were used to treat femoral neck fractures in patients with neurological disorders. We retrospectively studied a group of patients with Parkinson's disease and poliomyelitis who sustained femoral neck fractures and were treated by total hip arthroplasty using an L-MoM prosthesis. Materials and Methods: We retrospectively reviewed 12 hips in 12 patients who underwent large-diameter metal-on-metal (L-MoM) total hip replacement between May 2007 and October 2009. Eight of the 12 patients (8 hips; 66.7%) had Parkinson's disease and 4 patients (4 hips; 33.3%) were affected with poliomyelitis. Results: The followup time was 5.2 years (range 3.6-6.0 years). At the latest followup, all the patients showed satisfactory clinical and radiographic results, with pain relief. No complications, such as dislocation or aseptic loosening occurred. Conclusion: We believe the use of L-MoM can diminish the rate of instability or dislocation, after operation. The L-MoM is an option for patients with Parkinson's disease and poliomyelitis with femoral neck fracture. PMID:25404774

  20. Corrosion on the acetabular liner taper from retrieved modular metal-on-metal total hip replacements.

    PubMed

    Gascoyne, Trevor C; Dyrkacz, Richard M; Turgeon, Thomas R; Burnell, Colin D; Wyss, Urs P; Brandt, Jan-M

    2014-10-01

    Eight retrieved metal-on-metal total hip replacements displayed corrosion damage along the cobalt-chromium alloy liner taper junction with the Ti alloy acetabular shell. Scanning electron microscopy indicated the primary mechanism of corrosion to be grain boundary and associated crevice corrosion, which was likely accelerated through mechanical micromotion and galvanic corrosion resulting from dissimilar alloys. Coordinate measurements revealed up to 4.3mm(3) of the cobalt-chromium alloy taper surface was removed due to corrosion, which is comparable to previous reports of corrosion damage on head-neck tapers. The acetabular liner-shell taper appears to be an additional source of metal corrosion products in modular total hip replacements. Patients with these prostheses should be closely monitored for signs of adverse reaction towards corrosion by-products.

  1. Primary total hip replacement versus hip resurfacing - hospital considerations.

    PubMed

    Ward, William G; Carter, Christina J; Barone, Marisa; Jinnah, Riyaz

    2011-01-01

    Multiple factors regarding surgical procedures and patient selection affect hospital staffing needs as well as hospital revenues. In order to better understand the potential impact on hospitals that hip arthroplasty device selection (standard total hip arthroplasty vs. resurfacing) creates, a review of all primary hip arthroplasties performed at one institution was designed to identify factors that impacted hospital staffing needs and revenue generation. All primary hip arthroplasties undertaken over three fiscal years (2008 to 2010) were reviewed, utilizing only hospital business office data and medical records data that had been previously extracted prior for billing purposes. Analysis confirmed differing demographics for two hip arthroplasty populations, with the resurfacing patients (compared to the conventional total hip arthroplasty population) consisting of younger patients (mean age, 50 vs. 61 years), who were more often male (75% vs. 45%), were more likely to have osteoarthritis as their primary diagnosis (83 vs. 67%) and were more often covered by managed care or commercial insurance (83 vs. 34%). They also had shorter hospital stays (mean length of stay, 2.3 vs. 4.1 days) and consequently provided a more favorable financial revenue stream to the hospital on a per patient basis. Several trends appeared during the study periods. There was a steady increase in all procedures in all groups except for the resurfacings, which decreased 26% in males and 53% in females between 2009 and 2010. Differences were observed in the demographics of patients presenting for resurfacing, compared to those presenting for conventional total hip arthroplasty. In addition to the revenue stream considerations, institutions undertaking a resurfacing program must commit the resources and planning in order to rehabilitate these patients more expeditiously than is usually required with conventional hip arthroplasty patients.

  2. Tribolayer formation in a metal-on-metal (MoM) hip joint: an electrochemical investigation.

    PubMed

    Mathew, M T; Nagelli, C; Pourzal, R; Fischer, A; Laurent, M P; Jacobs, J J; Wimmer, M A

    2014-01-01

    The demand for total hip replacement (THR) surgery is increasing in the younger population due to faster rehabilitation and more complete restoration of function. Up to 2009, metal-on-metal (MoM) hip joint bearings were a popular choice due to their design flexibility, post-operative stability and relatively low wear rates. The main wear mechanisms that occur along the bearing surface of MoM joints are tribochemical reactions that deposit a mixture of wear debris, metal ions and organic matrix of decomposed proteins known as a tribolayer. No in-depth electrochemical studies have been reported on the structure and characteristics of this tribolayer or about the parameters involved in its formation. In this study, we conducted an electrochemical investigation of different surfaces (bulk-like: control, nano-crystalline: new implant and tribolayer surface: retrieved implant) made out of two commonly used hip CoCrMo alloys (high-carbon and low-carbon). As per ASTM standard, cyclic polarization tests and electrochemical impedance spectroscopy tests were conducted. The results obtained from electrochemical parameters for different surfaces clearly indicated a reduction in corrosion for the tribolayer surface (Icorr: 0.76μA/cm(2)). Further, polarization resistance (Rp:2.39±0.60MΩ/cm(2)) and capacitance (Cdl:15.20±0.75μF/cm(2)) indicated variation in corrosion kinetics for the tribolayer surface, that attributed to its structure and stability in a simulated body environment.

  3. Clinical and Wear Analyses of 9 Large Metal-on-Metal Total Hip Prostheses

    PubMed Central

    Mathijssen, N. M. C.; Witt, F.; Morlock, M. M.; Vehmeijer, S. B. W.

    2016-01-01

    Background Metal-on-Metal (MoM) total hip arthroplasties (THA) are associated with pseudotumor formation and high revision rates. This prospective study analysed the clinical and wear analyses of 9 large Metal-on-Metal (MoM) total hip arthroplasties (THA) to understand the underlying mechanisms of failure. The MoM bearings were revised for multiple reasons; the main reason was pseudotumor formation. Materials and Methods From 2006 till 2010 the Reinier de Graaf Hospital implanted 160 large head M2a-Magnum™ (Biomet Inc. Warsaw, Indiana, USA) THAs in 150 patients. The first year, 9 bearings were revised and analysed at the Biomechanics Section, Hamburg University of Technology, Germany. We performed clinical (Harris Hip Score, radiographic analysis, blood cobalt and chromium) and wear analysis (implant, tissue and fluid) of the 9 bearings. Since this study did not fall under the scope of the Medical Research Involving Human Subjects Act in The Netherlands, no ethical approval was necessary. In this prospective study all patient details were anonymized by the corresponding author, all other authors were blinded during the research and wear analyses. Patients with bilateral MoM implants were excluded. Results The 9 bearings had a median (IQR) survival of 41.0 (25) months in situ. From these bearings, three showed no noticeable wear. The median (IQR) head wear volume was 3.2 (3.6) mm3 and maximum wear depth 0.02 (0.02) mm. For the cup the median (IQR) wear volume was 0.23 (0.3) mm3 with a maximum wear depth of 0.03 (0.05) mm. Conclusion An early identification of parameters related to failure of the MoM THA, such as pain, decreased range of motion, radiographic changes and high levels of blood cobalt and chromium is of great importance for patient’s quality of life. Especially now patients and surgeons face the long term effects of all these bearings still in situ. This study reports the clinical and wear analyses of 9 MoM THA. In the majority of this group the

  4. The Inflammatory Phenotype in Failed Metal-On-Metal Hip Arthroplasty Correlates with Blood Metal Concentrations

    PubMed Central

    Paukkeri, Erja-Leena; Korhonen, Riku; Hämäläinen, Mari; Pesu, Marko; Eskelinen, Antti; Moilanen, Teemu; Moilanen, Eeva

    2016-01-01

    Introduction Hip arthroplasty is the standard treatment of a painful hip destruction. The use of modern metal-on-metal (MOM) bearing surfaces gained popularity in total hip arthroplasties during the last decade. Recently, worrisome failures due to adverse reaction to metal debris (ARMD), including pseudotumor response, have been widely reported. However, the pathogenesis of this reaction remains poorly understood. The aim of the present study was to investigate the ARMD response by flow cytometry approach. Methods Sixteen patients with a failed Articular Surface Replacement (ASR) hip prosthesis were included in the study. Samples of pseudotumor tissues collected during revision surgery were degraded by enzyme digestion and cells were typed by flow cytometry. Whole blood chromium and cobalt concentrations were analyzed with mass spectrometry before revision surgery. Results Flow cytometry analysis showed that the peri-implant pseudotumor tissue expressed two principal phenotypes, namely macrophage-dominated and T-lymphocyte-dominated response; the average portions being 54% (macrophages) and 25% (T-lymphocytes) in macrophage-dominated inflammation and 20% (macrophages) and 54% (T-lymphocytes) in T-lymphocyte-dominated response. The percentages of B-lymphocytes and granulocytes were lower in both phenotypes. Interestingly, the levels of blood chromium and cobalt were significantly higher in patients with macrophage-dominated response. Conclusions The results suggest that the adverse tissue reactions induced by MOM wear particles contain heterogeneous pathogeneses and that the metal levels are an important factor in the determination of the inflammatory phenotype. The present results support the hypothesis that higher metal levels cause cytotoxicity and tissue injury and macrophages are recruited to clear the necrotic debris. On the other hand, the adverse response developed in association with lower metal levels is T-lymphocyte-dominated and is likely to reflect

  5. Characterisation of wear particles produced by metal on metal and ceramic on metal hip prostheses under standard and microseparation simulation.

    PubMed

    Brown, Christopher; Williams, Sophie; Tipper, Joanne L; Fisher, John; Ingham, Eileen

    2007-05-01

    The failure of metal on polyethylene total hip replacements due to wear particle induced osteolysis and late aseptic loosening has focused interest upon alternative bearings, such as metal on metal implants. A recent advance in this field has been the development of a novel ceramic on metal implant. The characteristics of the wear particles generated in this low-wearing bearing have not been previously determined. The aims of this study were to characterise metal wear particles from metal on metal and ceramic on metal hips under standard and adverse (microseparation) wear conditions. Accurate characterisation of cobalt-chrome wear particles is difficult since the reactive nature of the particles prevents them from being isolated using acids and bases. A method was developed to isolate the metal wear particles using enzymes to digest serum containing lubricants from metal on metal and ceramic on metal hip simulations. High resolution scanning electron microscopy was then used to characterise the wear particles generated by both metal on metal and ceramic on metal implants under standard and microseparation wear conditions. The wear particles isolated from all simulations had a mean size of less than 50 nm with a rounded and irregular morphology. No significant difference was found between the size of wear particles generated under any conditions.

  6. Wear evaluation of cobalt-chromium alloy for use in a metal-on-metal hip prosthesis.

    PubMed

    St John, Kenneth R; Zardiackas, Lyle D; Poggie, Robert A

    2004-01-15

    Wear of the polyethylene in total joint prostheses has been a source of morbidity and early device failure, which has been extensively reported in the last 20 years. Although research continues to attempt to reduce the wear of polyethylene joint-bearing surfaces by modifications in polymer processing, there is a renewed interest in the use of metal-on-metal bearing couples for hip prostheses. Wear testing of total hip replacement systems involving the couple of metal or ceramic heads on polymeric acetabular components has been performed and reported, but, until recently, there has been little data published for pin-on-disk or hip-simulator wear studies involving the combination of a metallic femoral head component with an acetabular cup composed of the same or a dissimilar metal. This study investigated the in vitro wear resistance of two cobalt/chromium/molybdenum alloys, which differed primarily in the carbon content, as potential alloys for use in a metal-on-metal hip-bearing couple. The results of pin-on-disk testing showed that the alloy with the higher (0.25%) carbon content was more wear resistant, and this alloy was therefore chosen for testing in a hip-simulator system, which modeled the loads and motions that might be exerted clinically. Comparison of the results of metal-on-polyethylene samples to metal-on-metal samples showed that the volumetric wear of the metal-on-polyethylene bearing couple after 5,000,000 cycles was 110-180 times that for the metal-bearing couple. Polyethylene and metal particles retrieved from either the lubricant for pin-on-disk testing or hip simulator testing were characterized and compared with particles retrieved from periprosthetic tissues by other researchers, and found to be similar. Based upon the results of this study, metal-on-metal hip prostheses manufactured from the high carbon cobalt/chromium alloy that was investigated hold sufficient promise to justify human clinical trials.

  7. Perfusion MRI in hips with metal-on-metal and metal-on-polyethylene total hip arthroplasty

    PubMed Central

    Anwander, H.; Cron, G. O.; Rakhra, K.

    2016-01-01

    Objectives Hips with metal-on-metal total hip arthroplasty (MoM THA) have a high rate of adverse local tissue reactions (ALTR), often associated with hypersensitivity reactions. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measures tissue perfusion with the parameter Ktrans (volume transfer constant of contrast agent). Our purpose was 1) to evaluate the feasibility of DCE-MRI in patients with THA and 2) to compare DCE-MRI in patients with MoM bearings with metal-on-polyethylene (MoP) bearings, hypothesising that the perfusion index Ktrans in hips with MoM THA is higher than in hips with MoP THA. Methods In this pilot study, 16 patients with primary THA were recruited (eight MoM, eight MoP). DCE-MRI of the hip was performed at 1.5 Tesla (T). For each patient, Ktrans was computed voxel-by-voxel in all tissue lateral to the bladder. The mean Ktrans for all voxels was then calculated. These values were compared with respect to implant type and gender, and further correlated with clinical parameters. Results There was no significant difference between the two bearing types with both genders combined. However, dividing patients by THA bearing and gender, women with MoM bearings had the highest Ktrans values, exceeding those of women with MoP bearings (0.067 min−1 versus 0.053 min−1; p-value < 0.05) and men with MoM bearings (0.067 min−1 versus 0.034 min−1; p-value < 0.001). Considering only the men, patients with MoM bearings had lower Ktrans than those with MoP bearings (0.034 min−1 versus 0.046 min−1; p < 0.05). Conclusion DCE-MRI is feasible to perform in tissues surrounding THA. Females with MoM THA show high Ktrans values in DCE-MRI, suggesting altered tissue perfusion kinematics which may reflect relatively greater inflammation. Cite this article: Dr P. E. Beaule. Perfusion MRI in hips with metal-on-metal and metal-on-polyethylene total hip arthroplasty: A pilot stud. Bone Joint Res 2016;5:73–79. DOI: 10

  8. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint femoral (hemi-hip) metallic resurfacing... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3400 Hip joint femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip joint femoral...

  9. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hip joint femoral (hemi-hip) metallic resurfacing... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3400 Hip joint femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip joint femoral...

  10. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hip joint femoral (hemi-hip) metallic resurfacing... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3400 Hip joint femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip joint femoral...

  11. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hip joint femoral (hemi-hip) metallic resurfacing... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3400 Hip joint femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip joint femoral...

  12. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) metallic resurfacing... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3400 Hip joint femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip joint femoral...

  13. The Tribology of Explanted Hip Resurfacings Following Early Fracture of the Femur.

    PubMed

    Lord, James K; Langton, David J; Nargol, Antoni V F; Meek, R M Dominic; Joyce, Thomas J

    2015-10-15

    A recognized issue related to metal-on-metal hip resurfacings is early fracture of the femur. Most theories regarding the cause of fracture relate to clinical factors but an engineering analysis of failed hip resurfacings has not previously been reported. The objective of this work was to determine the wear volumes and surface roughness values of a cohort of retrieved hip resurfacings which were removed due to early femoral fracture, infection and avascular necrosis (AVN). Nine resurfacing femoral heads were obtained following early fracture of the femur, a further five were retrieved due to infection and AVN. All fourteen were measured for volumetric wear using a co-ordinate measuring machine. Wear rates were then calculated and regions of the articulating surface were divided into "worn" and "unworn". Roughness values in these regions were measured using a non-contacting profilometer. The mean time to fracture was 3.7 months compared with 44.4 months for retrieval due to infection and AVN. Average wear rates in the early fracture heads were 64 times greater than those in the infection and AVN retrievals. Given the high wear rates of the early fracture components, such wear may be linked to an increased risk of femoral neck fracture.

  14. A lexicon for wear of metal-on-metal hip prostheses.

    PubMed

    McKellop, Harry A; Hart, Alister; Park, Sang-Hyun; Hothi, Harry; Campbell, Pat; Skinner, John A

    2014-09-01

    Research on metal-on-metal (MoM) hip bearings has generated an extensive vocabulary to describe the wear processes and resultant surface damage. However, a lack of consistency and some redundancy exist in the current terminology. To facilitate the understanding of MoM tribology and to enhance communication of results among researchers and clinicians, we propose four categories of wear terminology: wear modes refer to the in vivo conditions under which the wear occurred; wear mechanisms refer to fundamental wear processes (adhesion, abrasion, fatigue, and tribochemical reactions); wear damage refers to the resultant changes in the morphology and/or composition of the surfaces; and wear features refer to the specific wear phenomena that are described in terms of the relevant modes, mechanisms, and damage. Clarifying examples are presented, but it is expected that terms will be added to the lexicon as new mechanisms and types of damage are identified. Corrosion refers to electrochemical processes that can remove or add material and thus also generate damage. Corrosion can act alone or may interact with mechanical wear. Examples of corrosion damage are also presented. However, an in-depth discussion of the many types of corrosion and their effects is beyond the scope of the present wear lexicon.

  15. Cross-sectional imaging of metal-on-metal hip arthroplasties

    PubMed Central

    Robinson, Elizabeth; Henckel, Johann; Sabah, Shiraz; Satchithananda, Keshthra; Skinner, John; Hart, Alister

    2014-01-01

    Background and purpose — Metal artifact reduction sequence (MARS) MRI is widely advocated for surveillance of metal-on-metal hip arthroplasties (MOM-HAs). However, its use is limited by susceptibility artifact at the prosthesis-bone interface, local availability, patient compliance, and cost (Hayter et al. 2011a). We wanted to determine whether CT is a suitable substitute for MARS MRI in evaluation of the painful MOM-HA. Patients and methods — 50 MOM-HA patients (30 female) with unexplained painful prostheses underwent MARS MRI and CT imaging. 2 observers who were blind regarding the clinical data objectively reported the following outcomes: soft tissue lesions (pseudotumors), muscle atrophy, and acetabular and femoral osteolysis. Diagnostic test characteristics were calculated. Results — Pseudotumor was diagnosed in 25 of 50 hips by MARS MRI and in 11 of 50 by CT. Pseudotumors were classified as type 1 (n = 2), type 2A (n = 17), type 2B (n = 4), and type 3 (n = 2) by MARS MRI. CT did not permit pseudotumor classification. The sensitivity of CT for diagnosis of pseudotumor was 44% (95% CI: 25–65). CT had “slight” agreement with MARS MRI for quantification of muscle atrophy (κ = 0.23, CI: 0.16–0.29; p < 0.01). Osteolysis was identified in 15 of 50 patients by CT. 4 of these lesions were identified by MARS MRI. Interpretation — CT was found to be superior to MRI for detection of osteolysis adjacent to MOM-HA, and should be incorporated into diagnostic algorithms. CT was unable to classify and failed to detect many pseudotumors, and it was unreliable for assessment of muscle atrophy. Where MARS MRI is contraindicated or unavailable, CT would be an unsuitable substitute and other modalities such as ultrasound should be considered PMID:25267500

  16. Midterm results of 36 mm metal-on-metal total hip arthroplasty

    PubMed Central

    Akrawi, Hawar; Hossain, Fahad S; Niculescu, Stefan; Hashim, Zaid; Ng, Arron Biing; Shetty, Ajit

    2016-01-01

    Background: Despite the many perceived benefits of metal-on-metal (MoM) articulation in total hip arthroplasty (THA), there have been growing concerns about metallosis and adverse reaction to metal debris (ARMD). Analysis of size 36 mm MoM articulation THAs is presented. These patients were evaluated for patient characteristics, relationship between blood metal ions levels and the inclination as well as the version of acetabular component, cumulative survival probability at final followup and functional outcome at final followup. Materials and Methods: 288, size 36 mm MoM THAs implanted in 269 patients at our institution from 2004 to 2010 were included in this retrospective study. These patients were assessed clinically for hip symptoms, perioperative complications and causes of revision arthroplasty were analysed. Biochemically, blood cobalt and chromium metal ions level were recorded and measurements of acetabular inclination and version were examined. Radiological evaluation utilizing Metal Artefact Reduction Sequence (MARS) MRI was undertaken and implant cumulative survivorship was evaluated. Results: The mean followup was 5 years (range 2–7 years), mean age was 73 years and the mean Oxford hip score was 36.9 (range 5–48). Revision arthroplasty was executed in 20 (7.4%) patients, of which 15 patients underwent single-stage revision THA. The causes of revision arthroplasty were: ARMD changes in 6 (2.2%) patients, infection in 5 (1.9%) patients and aseptic loosening in 5 (1.9%) patients. Three (1.1%) patients had their hips revised for instability, 1 (0.3%) for raised blood metal ions levels. The implant cumulative survival rate, with revision for any reason, was 68.9% at 7 years. Conclusions: Although medium-sized MoM THA with a 36 mm head has a marginally better survivorship at midterm followup, compared to larger size head MoM articulating THA, our findings nonetheless are still worryingly poor in comparison to what has been quoted in the literature

  17. The Correlation of Serum Metal Ions with Functional Outcome Scores at Three-to-Six Years following Large Head Metal-on-Metal Hip Arthroplasty

    PubMed Central

    Patange Subbarao, Sheethal Prasad; Malek, Ibrahim A.; Mohanty, Khitish; Thomas, Phillip; John, Alun

    2013-01-01

    Based on success of hip resurfacing, large head Metal on Metal (MoM) hip arthroplasty has gained significant popularity in recent years. There are growing concerns about metal ions related soft tissue abnormalities. The aim of this study was to define a correlation of metal ions with various functional outcome scores following large head MoM hip arthroplasty. Consecutive cohort of 70 patients (76 hips) with large head MoM hip arthroplasty using SL-Plus femoral stem and Cormet acetabular component were prospectively followed up. An independent observer assessed the patients which included serology for metal ion levels and collection of Oxford Hip, Harris hip, WOMAC, SF-36 & modified UCLA scores. Median serum cobalt and chromium levels were 3.10 μg/L (0.35–62.92) and 4.21 μg/L (0.73–69.27) with total of median 7.30 μg/L (2.38–132.19). The median Oxford, Harris, WOMAC, SF-36 and modified UCLA scores were 36 (6–48), 87 (21–100), 36 (24–110), 104 (10–125), and 3 (1–9), respectively. Seventeen patients had elevated serum cobalt and chromium levels ≥7 μg/L. There was no significant correlation between serum metal ion levels with any of these outcome scores. We recommend extreme caution during follow up of these patients with large head MoM arthroplasty. PMID:24959353

  18. Wear behaviour of cobalt-chromium-molybdenum alloys used in metal-on-metal hip implants

    NASA Astrophysics Data System (ADS)

    Varano, Rocco

    The influence of carbon (C) content, microstructure, crystallography and mechanical properties on the wear behaviour of metal-on-metal (MM) hip implants made from commercially available cobalt-chromium-molybdenum (CoCrMo) alloys designated as American Society of Testing and Materials (ASTM) grade F1537, F75 and as-cast were studied in this work. The as-received bars of wrought CoCrMo alloys (ASTM F1537 of either about 0.05% or 0.26% C) were each subjected to various heat treatments to develop different microstructures. Pin and plate specimens were fabricated from each bar and were tested against each other using a linear reciprocating pin-on-plate apparatus in 25% by volume bovine serum solution. The applied normal load was 9.81 N and the reciprocating plate had a sinusoidal velocity with an average speed of 26 mm/s. The wear was measured gravimetrically and it was found to be most strongly affected by alloy C content, irrespective of grain size or carbide morphology. More precisely, the wear behaviour was directly correlated to the dissolved C content of the alloys. Increased C in solid-solution coincided with lower volumetric wear since C helps to stabilize the face-centred cubic (FCC) crystal structure thus limiting the amount of strain induced transformation (SIT) to the hexagonal close-packed crystal structure (HCP). Based on the observed surface twinning in and around the contact zone and the potentially detrimental effect of the HCP phase, it was postulated that the MM wear behaviour of CoCrMo alloys in the present study was controlled by a deformation mechanism, rather than corrosion or tribochemical reactions.

  19. Contact mechanics and elastohydrodynamic lubrication in a novel metal-on-metal hip implant with an aspherical bearing surface.

    PubMed

    Meng, Qingen; Gao, Leiming; Liu, Feng; Yang, Peiran; Fisher, John; Jin, Zhongmin

    2010-03-22

    Diameter and diametral clearance of the bearing surfaces of metal-on-metal hip implants and structural supports have been recognised as key factors to reduce the dry contact and hydrodynamic pressures and improve lubrication performance. On the other hand, application of aspherical bearing surfaces can also significantly affect the contact mechanics and lubrication performance by changing the radius of the curvature of a bearing surface and consequently improving the conformity between the head and the cup. In this study, a novel metal-on-metal hip implant employing a specific aspherical bearing surface, Alpharabola, as the acetabular surface was investigated for both contact mechanics and elastohydrodynamic lubrication under steady-state conditions. When compared with conventional spherical bearing surfaces, a more uniform pressure distribution and a thicker lubricant film thickness within the loaded conjunction were predicted for this novel Alpharabola hip implant. The effects of the geometric parameters of this novel acetabular surface on the pressure distribution and lubricant thickness were investigated. A significant increase in the predicted lubricant film thickness and a significant decrease in the dry contact and hydrodynamic pressures were found with appropriate combinations of these geometric parameters, compared with the spherical bearing surface.

  20. Histologic, serologic, and tribologic findings in failed metal-on-metal total hip arthroplasty: AAOS exhibit selection.

    PubMed

    Pelt, Christopher E; Erickson, Jill; Clarke, Ian; Donaldson, Thomas; Layfield, Lester; Peters, Christopher L

    2013-11-06

    Despite multiple changes in second-generation metal-on-metal hip implants, greater-than-expected revision rates have led to alarm. We hypothesized that the finding of intraoperative metallosis would be associated with a high metal load on histologic analysis and that both would be associated with increased wear, greater serum metal ion levels, and predictable biologic responses in the histologic sections. We evaluated the implant positioning, serum ion levels, intraoperative findings of metallosis, wear characteristics of retrieved implants (tribology), histology, and outcomes in a series of eighteen large-diameter metal-on-metal total hip arthroplasties. The arthroplasties were divided into two groups on the basis of the intraoperative finding of metallosis and into two groups on the basis of the metal load score. Intraoperative metallosis was not associated with a high metal load score (p = 0.15). The finding of intraoperative metallosis was associated with greater serum metal ion levels, greater wear rates, and greater complication rates. Aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) scores were similar between the metallosis and non-metallosis groups (p = 0.49) as well as between the high and low-metal-load groups (p = 0.56).

  1. Understanding the differences between the wear of metal-on-metal and ceramic-on-metal total hip replacements.

    PubMed

    Figueiredo-Pina, C G; Yan, Y; Neville, A; Fisher, J

    2008-04-01

    Hip simulator studies have been carried out extensively to understand and test artificial hip implants in vitro as an efficient alternative to obtaining long-term results in vivo. Recent studies have shown that a ceramic-on-metal material combination lowers the wear by up to 100 times in comparison with a typical metal-on-metal design. The reason for this reduction remains unclear and for this reason this study has undertaken simple tribometer tests to understand the fundamental material loss mechanisms in two material combinations: metal-on-metal and ceramic-on-ceramic. A simple-configuration reciprocating pin-on-plate wear study was performed under open-circuit potential (OCP) and with applied cathodic protection (CP) in a serum solution using two tribological couples: firstly, cobalt-chromium (Co-Cr) pins against Co-Cr plates; secondly, Co-Cr pins against alumina (Al2O3) plates. The pin and plate surfaces prior to and after testing were examined by profilometry and scanning electron microscopy. The results showed a marked reduction in wear when CP was applied, indicating that total material degradation under the OCP condition was attributed to corrosion processes. The substitution of the Co-Cr pin with an Al2O3 plate also resulted in a dramatic reduction in wear, probably due to the reduction in the corrosion-wear interactions between the tribological pair.

  2. Good sensitivity and specificity of ultrasound for detecting pseudotumors in 83 failed metal-on-metal hip replacements

    PubMed Central

    Lainiala, Olli; Elo, Petra; Reito, Aleksi; Pajamäki, Jorma; Puolakka, Timo; Eskelinen, Antti

    2015-01-01

    Background and purpose Ultrasound is used for imaging of pseudotumors associated with metal-on-metal (MoM) hips. Ultrasound has been compared with magnetic resonance imaging, but to date there have been no studies comparing ultrasound findings and revision findings. Methods We evaluated the sensitivity and specificity of preoperative ultrasound for detecting pseudotumors in 82 patients with MoM hip replacement (82 hips). Ultrasound examinations were performed by 1 of 3 musculoskeletal radiologists, and pseudotumors seen by ultrasound were retrospectively classified as fluid-filled, mixed-type, or solid. Findings at revision surgery were retrieved from surgical notes and graded according to the same system as used for ultrasound findings. Results Ultrasound had a sensitivity of 83% (95% CI: 63–93) and a specificity of 92% (CI: 82–96) for detecting trochanteric region pseudotumors, and a sensitivity of 79% (CI: 62–89) and a specificity of 94% (CI: 83–98) for detecting iliopsoas-region pseudotumors. Type misclassification of pseudotumors found at revision occurred in 8 of 23 hips in the trochanteric region and in 19 of 33 hips in the iliopsoas region. Interpretation Despite the discrepancy in type classification between ultrasound and revision findings, the presence of pseudotumors was predicted well with ultrasound in our cohort of failed MoM hip replacements. PMID:25582840

  3. Progressive Cardiomyopathy in a Patient With Elevated Cobalt Ion Levels and Bilateral Metal-on-Metal Hip Arthroplasties.

    PubMed

    Mosier, Brian A; Maynard, Lance; Sotereanos, Nicholas G; Sewecke, Jeffrey J

    2016-01-01

    Systemic cobalt toxicity is a rare complication after metal-on-metal (MOM) total hip arthroplasty. Here we present a case of progressive cardiomyopathy, as evidenced by biopsy and cardiac magnetic resonance imaging (MRI), in a patient with bilateral MOM total hip arthroplasties. To our knowledge, it is one of the first cases in which cardiomyopathy resulting from systemic cobalt disease has been shown on MRI. While there is no guideline to unequivocally diagnose cobalt cardiomyopathy, the constellation of findings, including pathologic, biologic, blood levels, imaging, and surgical, all uniformly indicate a unifying diagnosis. The lack of improvement after removal of the prosthetic device supports a diagnosis of permanent myocardial damage, which is consistent with cardiomyopathy of advanced toxic etiology.

  4. The chemical form of metallic debris in tissues surrounding metal-on-metal hips with unexplained failure.

    PubMed

    Hart, Alister J; Quinn, Paul D; Sampson, Barry; Sandison, Ann; Atkinson, Kirk D; Skinner, John A; Powell, Jonathan J; Mosselmans, J Fred W

    2010-11-01

    Implant-derived material from metal-on-metal (MOM) hip arthroplasties may be responsible for an unexplained tissue inflammatory response. The chemical form of the metal species in the tissues is predominantly chromium (Cr), but the currently used techniques have not been able to determine whether this is Cr(III) phosphate or Cr(III) oxide. The analytical challenge must overcome the fact that the metal in the tissues is at a relatively low concentration and tissue preparation or the microscopy beam used can affect the results. Microfocus X-ray spectroscopy using a synchrotron beam is useful in addressing both these issues. Using this technique we compared tissue from failed MOM hips with: (1) tissue from metal-on-polyethylene (MOP) hips; (2) chemical standards; (3) metal discs cut from MOM hips. The most abundant implant-related species in all MOM hip tissues contained Cr. Comparison with standards revealed the chemical form was Cr(III) phosphate, which did not vary with manufacturer type (four types analysed) or level of blood metal ions. Cobalt (Co) and molybdenum (Mo) were occasionally present in areas of high Cr. Co was normally found in a metallic state in the tissue, while Mo was found in an oxidized state. The variety of metallic species may have arisen from corrosion, wear or a combination of both. No evidence of Cr(VI) was seen in the tissues examined.

  5. Effects of metal-on-metal wear on the host immune system and infection in hip arthroplasty

    PubMed Central

    2010-01-01

    Background and purpose Joint replacement with metal-on-metal (MOM) bearings have gained popularity in the last decades in young and active patients. However, the possible effects of MOM wear debris and its corrosion products are still the subject of debate. Alongside the potential disadvantages such as toxicity, the influences of metal particles and metal ions on infection risk are unclear. Methods We reviewed the available literature on the influence of degradation products of MOM bearings in total hip arthroplasties on infection risk. Results Wear products were found to influence the risk of infection by hampering the immune system, by inhibiting or accelerating bacterial growth, and by a possible antibiotic resistance and heavy metal co-selection mechanism. Interpretation Whether or not the combined effects of MOM wear products make MOM bearings less or more prone to infection requires investigation in the near future. PMID:20860450

  6. Cobalt to Chromium Ratio is Not a Key Marker for Adverse Local Tissue Reaction (ALTR) in Metal on Metal Hips.

    PubMed

    Fehring, Thomas K; Carter, Joshua L; Fehring, Keith A; Odum, Susan M; Griffin, William L

    2015-09-01

    The diagnosis of adverse local tissue reaction (ALTR) after metal-on-metal total hip arthroplasty (MoMTHA) presents a significant challenge. No single biomarker is specific for ALTR. The purpose of this study was to determine if the ratio of cobalt to chromium ions is useful for diagnosing ALTR in MoMTHA. In 89 bearing-related revision THAs, preoperative cobalt and chromium ion levels were compared to an intraoperative soft tissue damage grading scale. The average cobalt to chromium ratio was 2.96 (0-20). There was no correlation between the tissue scale and the cobalt to chromium ratio (R=0.095; P=0.41). Many variables affecting ion production/excretion mitigate the use of the ion ratio. The cobalt to chromium ratio is not a predictive biomarker for ALTR in MoMTHA.

  7. MRI findings following metal on metal hip arthroplasty and their relationship with metal ion levels and acetabular inclination angles.

    PubMed

    Fox, Ciara M; Bergin, Karen M; Kelly, Gabrielle E; McCoy, Gerry F; Ryan, Anthony G; Quinlan, John F

    2014-08-01

    Following the global recall of all ASR metal on metal hip products, our aim was to correlate MRI findings with acetabular inclination angles and metal ion levels in patients with these implants. Both cobalt and chromium levels were significantly higher in the presence of a periprosthetic fluid collection. There was no association between the presence of a periprosthetic mass, bone marrow oedema, trochanteric bursitis or greater levels of abductor muscle destruction for cobalt or chromium. There was no association between the level of periprosthetic tissue reaction and the acetabular inclination angle with any of the pathologies identified on MRI. The relationship between MRI pathology, metal ion levels and acetabular inclination angles in patients with ASR implants remains unclear adding to the complexity of managing patients.

  8. The trochanter slide osteotomy approach for resurfacing hip arthroplasty.

    PubMed

    Pitto, Rocco P

    2009-04-01

    The aim of this prospective study was to assess the safety and efficacy of the greater trochanter slide osteotomy approach for resurfacing hip arthroplasty. Fifty consecutive hips (47 patients) with degenerative joint disease were enrolled in the study. Serial clinical and radiological assessments were performed after the index operation. At 1-year follow-up, the clinical outcome and patient satisfaction were rated excellent or good in all hips. The radiological assessment showed signs of satisfactory implant alignment. Periprosthetic fractures and non-unions of the greater trochanter were not observed. The greater trochanter slide osteotomy approach for resurfacing hip arthroplasty is a safe procedure and provides optimal exposure of the acetabulum and proximal femur, maintaining the soft-tissue integrity of the hip joint. Blood supply of the proximal femur is not violated using this approach.

  9. Serum aluminium and cobalt levels after ceramic-on-ceramic and metal-on-metal total hip replacement.

    PubMed

    Grübl, A; Weissinger, M; Brodner, W; Gleiss, A; Giurea, A; Gruber, M; Pöll, G; Meisinger, V; Gottsauner-Wolf, F; Kotz, R

    2006-08-01

    In a randomised study, 28 patients with a mean age of 62.2 years (32 to 81) with osteoarthritis or avascular necrosis of the hip received either a ceramic-on-ceramic or a metal-on-metal total hip replacement. Apart from the liners the acetabular and femoral components were made of Ti-Al-Nb alloy. The serum aluminium and cobalt levels were measured before, and at one year after surgery. The 15 patients in the ceramic-on-ceramic group had a median pre-operative aluminium level of 1.3 microg/l (0.25 to 8.4) and a cobalt level below the detection limit. At one year the aluminium level was 1.1 microg/l (0.25 to 2.3) and the cobalt level was 0.4 microg/l (0.15 to 0.7). The 13 patients in the metal-on-metal group had a median pre-operative aluminium level of 1.9 microg/l (0.25 to 4.4) and a cobalt level below the detection limit. At one year the median aluminium level was 0.9 microg/l (0.25 to 3.9) whereas the cobalt level was 1.4 microg/l (0.5 to 10.5). This increase in the cobalt level at one year was significant (p < 0.001). Our findings indicate that ceramic-on-ceramic bearings do not cause elevated levels of serum aluminium in the first post-operative year.

  10. Disappointing short-term results with the DePuy ASR XL metal-on-metal total hip arthroplasty.

    PubMed

    Bernthal, Nicholas M; Celestre, Paul C; Stavrakis, Alexandra I; Ludington, John C; Oakes, Daniel A

    2012-04-01

    Outcomes of ultralarge-diameter femoral heads used in metal-on-metal (MOM) total hip arthroplasty (THA) are relatively unknown. This study reports on early failures of the ASR XL (Depuy, Warsaw, Ind) and assesses whether a correlation with cup positioning exists. A retrospective review of 70 consecutive MOM THAs with ultralarge-diameter femoral head and monoblock acetabular component was conducted. Minimum follow-up was 24 months. Of 70 THAs, 12 (17.1%) required revision within 3 years for pain (7), loosening (3), and squeaking (2). Three additional THAs noted squeaking, 2 noted grinding, and 3 additional hips had persistent pain. In total, 20 (28.6%) of 70 demonstrated implant dysfunction. Acetabular components for all symptomatic hips were in acceptable range of cup abduction and anteversion. The failures noted with this design do not correlate to cup placement. The high rate of implant dysfunction at early follow-up suggests serious concerns with the concept of MOM THA with an ultralarge-diameter femoral head paired with a monoblock acetabular cup.

  11. Prevalence of Failure due to Adverse Reaction to Metal Debris in Modern, Medium and Large Diameter Metal-on-Metal Hip Replacements – The Effect of Novel Screening Methods: Systematic Review and Metaregression Analysis

    PubMed Central

    Reito, Aleksi; Lainiala, Olli; Elo, Petra; Eskelinen, Antti

    2016-01-01

    Metal-on-metal (MoM) hip replacements were used for almost a decade before adverse reactions to metal debris (ARMD) were found to be a true clinical problem. Currently, there is a paucity of evidence regarding the usefulness of systematic screening for ARMD. We implemented a systematic review and meta-analysis to establish the prevalence of revision confirmed ARMD stratified by the use of different screening protocols in patients with MoM hip replacements. Five levels of screening were identified: no screening (level 0), targeted blood metal ion measurement and/or cross-sectional imaging (level 1), metal ion measurement without imaging (level 2), metal ion measurement with targeted imaging (level 3) and comprehensive screening (both metal ions and imaging for all; level 4). 122 studies meeting our eligibility criteria were included in analysis. These studies included 144 study arms: 100 study arms with hip resurfacings, 33 study arms with large-diameter MoM total hip replacements (THR), and 11 study arms with medium-diameter MoM THRs. For hip resurfacing, the lowest prevalence of ARMD was seen with level 0 screening (pooled prevalence 0.13%) and the highest with level 4 screening (pooled prevalace 9.49%). Pooled prevalence of ARMD with level 0 screening was 0.29% and with level 4 screening 21.3% in the large-diameter MoM THR group. In metaregression analysis of hip resurfacings, level 4 screening was superior with regard to prevalence of ARMD when compared with other levels. In the large diameter THR group level 4 screening was superior to screening 0,2 and 3. These outcomes were irrespective of follow-up time or study publication year. With hip resurfacings, routine cross-sectional imaging regardless of clinical findings is advisable. It is clear, however, that targeted metal ion measurement and/or imaging is not sufficient in the screening for ARMD in any implant concepts. However, economic aspects should be weighed when choosing the preferred screening level

  12. Does bearing size influence metal ion levels in large-head metal-on-metal total hip arthroplasty? A comparison of three total hip systems

    PubMed Central

    2014-01-01

    Background The purpose of the study was twofold: first, to determine whether there is a statistically significant difference in the metal ion levels among three different large-head metal-on-metal (MOM) total hip systems. The second objective was to assess whether position of the implanted prostheses, patient demographics or factors such as activity levels influence overall blood metal ion levels and whether there is a difference in the functional outcomes between the systems. Methods In a cross-sectional cohort study, three different metal-on-metal total hip systems were assessed: two monoblock heads, the Durom socket (Zimmer, Warsaw, IN, USA) and the Birmingham socket (Smith and Nephew, Memphis, TN, USA), and one modular metal-on-metal total hip system (Pinnacle, Depuy Orthopedics, Warsaw, IN, USA). Fifty-four patients were recruited, with a mean age of 59.7 years and a mean follow-up time of 41 months (12 to 60). Patients were evaluated clinically, radiologically and biochemically. Statistical analysis was performed on all collected data to assess any differences between the three groups in terms of overall blood metal ion levels and also to identify whether there was any other factor within the group demographics and outcomes that could influence the mean levels of Co and Cr. Results Although the functional outcome scores were similar in all three groups, the blood metal ion levels in the larger monoblock large heads (Durom, Birmingham sockets) were significantly raised compared with those of the Pinnacle group. In addition, the metal ion levels were not found to have a statistically significant relationship to the anteversion or abduction angles as measured on the radiographs. Conclusions When considering a MOM THR, the use of a monoblock large-head system leads to higher elevations in whole blood metal ions and offers no advantage over a smaller head modular system. PMID:24472283

  13. Are all metal-on-metal hip revision operations contributing to the National Joint Registry implant survival curves?

    PubMed Central

    Sabah, S. A.; Henckel, J.; Koutsouris, S.; Rajani, R.; Hothi, H.; Skinner, J. A.; Hart, A. J.

    2016-01-01

    Aims The National Joint Registry for England, Wales and Northern Ireland (NJR) has extended its scope to report on hospital, surgeon and implant performance. Data linkage of the NJR to the London Implant Retrieval Centre (LIRC) has previously evaluated data quality for hip primary procedures, but did not assess revision records. Methods We analysed metal-on-metal hip revision procedures performed between 2003 and 2013. A total of 69 929 revision procedures from the NJR and 929 revised pairs of components from the LIRC were included. Results We were able to link 716 (77.1%) revision procedures on the NJR to the LIRC. This meant that 213 (22.9%) revision procedures at the LIRC could not be identified on the NJR. We found that 349 (37.6%) explants at the LIRC completed the full linkage process to both NJR primary and revision databases. Data completion was excellent (> 99.9%) for revision procedures reported to the NJR. Discussion This study has shown that only approximately one third of retrieved components at the LIRC, contributed to survival curves on the NJR. We recommend prospective registry-retrieval linkage as a tool to feedback missing and erroneous data to the NJR and improve data quality. Take home message: Prospective Registry – retrieval linkage is a simple tool to evaluate and improve data quality on the NJR. Cite this article: Bone Joint J 2016;98-B:33–9. PMID:26733513

  14. A comparison of the diagnostic accuracy of MARS MRI and ultrasound of the painful metal-on-metal hip arthroplasty

    PubMed Central

    Siddiqui, Imran A; Sabah, Shiraz A; Satchithananda, Keshthra; Lim, Adrian K; Cro, Suzie; Henckel, Johann; Skinner, John A

    2014-01-01

    Background and purpose Metal artifact reduction sequence (MARS) MRI and ultrasound scanning (USS) can both be used to detect pseudotumors, abductor muscle atrophy, and tendinous pathology in patients with painful metal-on-metal (MOM) hip arthroplasty. We wanted to determine the diagnostic test characteristics of USS using MARS MRI as a reference for detection of pseudotumors and muscle atrophy. Patients and methods We performed a prospective cohort study to compare MARS MRI and USS findings in 19 consecutive patients with unilateral MOM hips. Protocolized USS was performed by consultant musculoskeletal radiologists who were blinded regarding clinical details. Reports were independently compared with MARS MRI, the imaging gold standard, to calculate predictive values. Results The prevalence of pseudotumors on MARS MRI was 68% (95% CI: 43–87) and on USS it was 53% (CI: 29–76). The sensitivity of USS in detecting pseudotumors was 69% (CI 39–91) and the specificity was 83% (CI: 36–97). The sensitivity of detection of abductor muscle atrophy was 47% (CI: 24–71). In addition, joint effusion was detected in 10 cases by USS and none were seen by MARS MRI. Interpretation We found a poor agreement between USS and MARS MRI. USS was inferior to MARS MRI for detection of pseudotumors and muscle atrophy, but it was superior for detection of joint effusion and tendinous pathologies. MARS MRI is more advantageous than USS for practical reasons, including preoperative planning and longitudinal comparison. PMID:24694273

  15. Clinical usefulness of blood metal measurements to assess the failure of metal-on-metal hip implants

    PubMed Central

    Sampson, Barry; Hart, Alister

    2012-01-01

    In April 2010, a Medicines and Healthcare Products Regulatory Agency safety alert concerning all metal-on-metal (MOM) hip replacements recommended measuring chromium and cobalt concentrations when managing patients with painful prostheses. The need for this review is illustrated by the recent surge in requests for these blood tests from orthopaedic surgeons following this alert. The aim is to provide guidance to laboratories in assessing these requests and advising clinicians on interpretation. First, we summarize the basic terminology regarding the types of hip replacements, with emphasis on the MOM type. Second, we describe the clinical concerns over implant-derived wear debris in the local tissues and distant sites. Analytical aspects of the measurement of the relevant metal ions and what factors affect the levels measured are discussed. The application of inductively coupled plasma mass spectrometry techniques to the measurement of these metals is considered in detail. The biological effects of metal wear products are summarized with local toxicity and systemic biological effects considered, including carcinogenicity, genotoxicity and systemic toxicity. Clinical cases are used to illustrate pertinent points. PMID:22155921

  16. Laboratory studies on the tribology of hard bearing hip prostheses: ceramic on ceramic and metal on metal.

    PubMed

    Vassiliou, K; Scholes, S C; Unsworth, A

    2007-01-01

    Total hip replacements offer relief to a great many patients every year around the world. With an expected service life of around 25 years on most devices, and with younger and younger patients undergoing this surgery, it is of great importance to understand the mechanisms of their function. Tribological testing of both conventional and hard bearing joint combinations have been conducted in many centres throughout the world, and, after being initially abandoned owing to premature failures, hard bearing combinations have been revisited as viable options for joint replacements. Improved design, manufacturing procedures, and material compositions have led to improved performance over first-generation designs in both metal-on-metal and ceramic-on-ceramic hip prostheses. This paper offers a review of the work conducted in an attempt to highlight the most important factors affecting joint performance and tribology of hard bearing combinations. The tribological performance of these joints is superior to that of conventional metal- or ceramic-on-polymer designs.

  17. On the matter of synovial fluid lubrication: implications for Metal-on-Metal hip tribology.

    PubMed

    Myant, Connor; Cann, Philippa

    2014-06-01

    Artificial articular joints present an interesting, and difficult, tribological problem. These bearing contacts undergo complex transient loading and multi axes kinematic cycles, over extremely long periods of time (>10 years). Despite extensive research, wear of the bearing surfaces, particularly metal-metal hips, remains a major problem. Comparatively little is known about the prevailing lubrication mechanism in artificial joints which is a serious gap in our knowledge as this determines film formation and hence wear. In this paper we review the accepted lubrication models for artificial hips and present a new concept to explain film formation with synovial fluid. This model, recently proposed by the authors, suggests that interfacial film formation is determined by rheological changes local to the contact and is driven by aggregation of synovial fluid proteins. The implications of this new mechanism for the tribological performance of new implant designs and the effect of patient synovial fluid properties are discussed.

  18. No association between serum metal ions and implant fixation in large-head metal-on-metal total hip arthroplasty

    PubMed Central

    Søballe, Kjeld; Jakobsen, Stig Storgaard; Lorenzen, Nina Dyrberg; Mechlenburg, Inger; Stilling, Maiken

    2014-01-01

    Background The mechanism of failure of metal-on-metal (MoM) total hip arthroplasty (THA) has been related to a high rate of metal wear debris, which is partly generated from the head-trunnion interface. However, it is not known whether implant fixation is affected by metal wear debris. Patients and methods 49 cases of MoM THA in 41 patients (10 women) with a mean age of 52 (28–68) years were followed with stereoradiographs after surgery and at 1, 2, and 5 years to analyze implant migration by radiostereometric analysis (RSA). Patients also participated in a 5- to 7-year follow-up with measurement of serum metal ions, questionnaires (Oxford hip score (OHS) and Harris hip score (HHS)), and measurement of cup and stem positions and systemic bone mineral density. Results At 1–2 years, mean total translation (TT) was 0.04 mm (95% CI: –0.07 to 0.14; p = 0.5) for the stems; at 2–5 years, mean TT was 0.13 mm (95% CI: –0.25 to –0.01; p = 0.03), but within the precision limit of the method. For the cups, there was no statistically significant TT or total rotation (TR) at 1–2 and 2–5 years. At 2–5 years, we found 4 cups and 5 stems with TT migrations exceeding the precision limit of the method. There was an association between cup migration and total OHS < 40 (4 patients, 4 hips; p = 0.04), but there were no statistically significant associations between cup or stem migration and T-scores < –1 (n = 10), cup and stem positions, or elevated serum metal ion levels (> 7µg/L (4 patients, 6 hips)). Interpretation Most cups and stems were well-fixed at 1–5 years. However, at 2–5 years, 4 cups and 5 stems had TT migrations above the precision limits, but these patients had serum metal ion levels similar to those of patients without measurable migrations, and they were pain-free. Patients with serum metal ion levels > 7 µg/L had migrations similar to those in patients with serum metal ion levels < 7 µg/L. Metal wear debris does not appear to influence the

  19. The utility of repeat ultrasound imaging in the follow-up of metal-on-metal hip arthroplasty patients

    PubMed Central

    Matharu, GS; Janardhan, S; Brash, L; Pynsent, PB; Dunlop, DJ; James, SLJ

    2016-01-01

    Introduction We assessed changes in metal-on-metal hip arthroplasties (MoMHAs) after repeat ultrasound examination. Methods This retrospective, single-centre cohort study involved all patients undergoing two ultrasound examinations of the same MoMHA. Between 2010 and 2014, 96 ultrasound examinations were performed in 48 MoMHAs (mean time between scans = 1.1 years). A radiologist assigned each scan to one of four grades and measured volumes of any solid/cystic masses. Changes in grade and lesion volume between scans were analysed. Results Change in grade between scans was significant (p=0.012); 27% (n=13) of MoMHAs increased in grade, 67% (n=32) had no grade change, and 6% (n=3) decreased in grade. The mean increase in lesion volume was 24.2cm3 by the second scan, and was significant (p=0.023). Evidence of progression in findings was observed in 54% (26/48) of MoMHAs. Of patients with normal scans initially, 44% (8/18) developed abnormalities. No factors (including blood metal ion concentrations and cup position) were associated significantly with progression of ultrasound findings. Conclusions Repeat ultrasound in MoMHA patients demonstrated that findings frequently progress in the short-term. Therefore, regular surveillance of MoMHA patients is important, with ultrasound representing an effective investigation for identifying the development and progression of lesions. PMID:26741659

  20. Friction moments of large metal-on-metal hip joint bearings and other modern designs.

    PubMed

    Bishop, N E; Waldow, F; Morlock, M M

    2008-10-01

    Modern hip joint replacements are designed to minimise wear problems. The most popular metal-on-polyethylene components are being updated by harder metal and ceramic combinations. However, this has also been shown to influence the friction moments, which could overload the interface between the implant and the body. In this study custom test apparatus was used to measure the joint moments in various modern bearings under simulated physiological joint conditions. The largest moments in serum were measured for large diameter metal-metal bearings (<8 Nm for standard bearings), followed by metal-polyethylene, and the lowest moments were for small diameter ceramic-ceramic and ceramic-metal combinations. Water as a lubricant was found to double the moments in comparison with serum. In metal-metal bearings moments were reduced by increasing loading frequency. Swing phase load and a rest period between load cycles had little effect. The moment magnitudes are within the turn-out capacity measured for press-fit cups and might become critical with higher joint loads.

  1. Comparison of synovial fluid, urine, and serum ion levels in metal-on-metal total hip arthroplasty at a minimum follow-up of 18 years.

    PubMed

    Lass, Richard; Grübl, Alexander; Kolb, Alexander; Stelzeneder, David; Pilger, Alexander; Kubista, Bernd; Giurea, Alexander; Windhager, Reinhard

    2014-09-01

    Diagnosis of adverse reactions to metal debris in metal-on-metal hip arthroplasty is a multifactorial process. Systemic ion levels are just one factor in the evaluation and should not be relied upon solely to determine the need for revision surgery. Furthermore, the correlation between cobalt or chromium serum, urine, or synovial fluid levels and adverse local tissue reactions is still incompletely understood. The hypothesis was that elevated serum and urine metal-ion concentrations are associated with elevated local metal-ion concentrations in primary total hip arthroplasties (THA) and with failure of metal-on-metal articulations in the long-term. In our present study, we evaluated these concentrations in 105 cementless THA with metal-on-metal articulating surfaces with small head diameter at a minimum of 18 years postoperatively. Spearman correlation showed a high correlation between the joint fluid aspirate concentration of cobalt and chromium with the serum cobalt (r = 0.81) and chromium level (r = 0.77) in patients with the THA as the only source of metal-ions. In these patients serum metal-ion analysis is a valuable method for screening. In patients with more than one source of metal or renal insufficiency additional investigations, like joint aspirations are an important tool for evaluation of wear and adverse tissue reactions in metal-on-metal THA.

  2. Characterization of protein degradation in serum-based lubricants during simulation wear testing of metal-on-metal hip prostheses.

    PubMed

    Maskiewicz, Victoria K; Williams, Paul A; Prates, Sarah J; Bowsher, John G; Clarke, Ian C

    2010-08-01

    A size exclusion high performance liquid chromatography (SEC-HPLC) method has been developed which is capable of separation and quantitation of bovine serum albumin (BSA) and bovine serum globulin (BSG) components of serum-based lubricant (SBL) solutions. This allowed characterization of the stability profiles of these proteins when acting as lubricants during hip wear simulation, and identification of wear-specific mechanisms of degradation. Using cobalt-chromium metal-on-metal (MOM) hip joints, it was observed that BSA remained stable for up to 3 days (215K cycles) of wear testing after which the protein degraded in a fairly linear fashion. BSG on the other hand, began to degrade immediately and in a linear fashion with a rate constant of 5% per day. Loss of both proteins occurred via the formation of high molecular weight aggregates which precipitated out of solution. No fragmentation of the polypeptide backbone of either protein was observed. Data obtained suggest that protein degradation was not due to microbial contamination, denaturation at the air-water interface, or frictional heating of articulating joint surfaces in these studies. We conclude that the primary source of protein degradation during MOM simulation testing occurs via high shear rates experienced by SBL solutions at articulating surfaces, possibly coupled with metal-protein interactions occurring as new and reactive metal surfaces are generated during wear testing. The development of this analytical methodology will allow new studies to clarify the role of SBL solutions in wear simulation studies and the interactions and lubricating properties of serum proteins with prosthetic surfaces other than MOM.

  3. Effect of 3D physiological loading and motion on elastohydrodynamic lubrication of metal-on-metal total hip replacements.

    PubMed

    Gao, Leiming; Wang, Fengcai; Yang, Peiran; Jin, Zhongmin

    2009-07-01

    An elastohydrodynamic lubrication (EHL) simulation of a metal-on-metal (MOM) total hip implant was presented, considering both steady state and transient physiological loading and motion gait cycle in all three directions. The governing equations were solved numerically by the multi-grid method and fast Fourier transform in spherical coordinates, and full numerical solutions were presented included the pressure and film thickness distribution. Despite small variations in the magnitude of 3D resultant load, the horizontal anterior-posterior (AP) and medial-lateral (ML) load components were found to translate the contact area substantially in the corresponding direction and consequently to result in significant squeeze-film actions. For a cup positioned anatomically at 45 degrees , the variation of the resultant load was shown unlikely to cause the edge contact. The contact area was found within the cup dimensions of 70-130 degrees and 90-150 degrees in the AP and ML direction respectively even under the largest translations. Under walking conditions, the horizontal load components had a significant impact on the lubrication film due to the squeeze-film effect. The time-dependent film thickness was increased by the horizontal translation and decreased during the reverse of this translation caused by the multi-direction of the AP load during walking. The minimum film thickness of 12-20 nm was found at 0.4s and around the location at (95, 125) degrees. During the whole walking cycle both the average and centre film thickness were found obviously increased to a range of 40-65 nm, compared with the range of 25-55 nm under one load (vertical) and one motion (flexion-extension) condition, which suggested the lubrication in the current MOM hip implant was improved under 3D physiological loading and motion. This study suggested the lubrication performance especially the film thickness distribution should vary greatly under different operating conditions and the time and

  4. Transient elastohydrodynamic lubrication analysis of a novel metal-on-metal hip prosthesis with a non-spherical femoral bearing surface.

    PubMed

    Meng, Q E; Liu, F; Fisher, J; Jin, Z M

    2011-01-01

    Effective lubrication performance of metal-on-metal hip implants only requires optimum conformity within the main loaded area, while it is advantageous to increase the clearance in the equatorial region. Such a varying clearance can be achieved by using non-spherical bearing surfaces for either acetabular or femoral components. An elastohydrodynamic lubrication model of a novel metal-on-metal hip prosthesis using a non-spherical femoral bearing surface against a spherical cup was solved under loading and motion conditions specified by ISO standard. A full numerical methodology of considering the geometric variation in the rotating non-spherical head in elastohydrodynamic lubrication solution was presented, which is applicable to all non-spherical head designs. The lubrication performance of a hip prosthesis using a specific non-spherical femoral head, Alpharabola, was analysed and compared with those of spherical bearing surfaces and a non-spherical Alpharabola cup investigated in previous studies. The sensitivity of the lubrication performance to the anteversion angle of the Alpharabola head was also investigated. Results showed that the non-spherical head introduced a large squeeze-film action and also led to a large variation in clearance within the loaded area. With the same equatorial clearance, the lubrication performance of the metal-on-metal hip prosthesis using an Alpharabola head was better than that of the conventional spherical bearings but worse than that of the metal-on-metal hip prosthesis using an Alpharabola cup. The reduction in the lubrication performance caused by the initial anteversion angle of the non-spherical head was small, compared with the improvement resulted from the non-spherical geometry.

  5. Fixation of a Periprosthetic Intertrochanteric Hip Fracture below a Birmingham Hip Resurfacing

    PubMed Central

    Macdonald, J.; Robinson, A.; Brown, I.

    2014-01-01

    This case report involves a 56-year-old female (Mrs X) with a traumatic intertrochanteric hip fracture with subtrochanteric extension below a previous Birmingham hip resurfacing. Periprosthetic fractures following hip resurfacing are usually subcapital and treated with a revision or conservative management. We present an unusual surgical problem with an interesting solution stabilising the fracture using a proximal femoral locking compression plate (LCP). Eight months following surgery the patient is able to walk pain free and there is good fixation and stability. PMID:24995142

  6. Revision of Metal-on-metal Hip Arthroplasty with Well Fixed and Positioned Acetabular Component Using a Dual-mobility Head and Review of Literature

    PubMed Central

    Figueras, Guillem; Planell, Ramón Vives; Fernàndez, Ramón Serra; Biayna, Joan Camí

    2016-01-01

    Background: As a consequence of use of metal-on-metal hip arthroplasties some patients have precised revision for pain or metal hipersensivity reactions among other causes. We propose to salvage monoblock acetabular component and femoral component using a dual-mobility head and perform a lower morbidity operation in young patients preserving host bone stock in cases with well fixed and positioned components. Objective: (1) What clinical problems have been reported in patients with Metal-on-metal hip arthroplasties? (2) Could the tribocorrosion potentially cause a fracture of neck femoral component? (3) Can be the dual-mobility head a recourse in metal-on-metal hip revision? Methods: Ten patients were revised for pain or/and raised Cobalt/Chromium levels between August 2012 and December 2015. In three cases femoral neck component was fractured and femoral revision was necessary. In four hips, acetabular and femoral components could be maintained. Age, body index mass, ion levels, acetabular position, size of acetabular component and femoral head, approach, blood transfunsion and time of hospitalization were analized. Results: At a mean follow-up of 25,6 months (6 to 45) the mean postoperative HHS was 92. It was not statistically significant because several patients were low sintomatic before surgery, but had raised Cobalt/Chromium levels in the blood. All patients had near-normal levels of Cobalt/Chromium during the first 6 months after revision surgery. No relevant complications were reported. Conclusion: The use of dual-mobility head can be an acceptable option to revise metal-on-metal arthroplasties correctly oriented with abscence of loosening or infection signs and keeping bone stock in young patients. PMID:27857822

  7. Wear of surface-engineered metal-on-metal bearings for hip prostheses under adverse conditions with the head loading on the rim of the cup.

    PubMed

    Leslie, Ian; Williams, Sophie; Isaac, Graham; Hatto, Peter; Ingham, Eileen; Fisher, John

    2013-04-01

    Clinical studies have found high wear rates, elevated ion levels and high revision rates of large-diameter metal-on-metal surface replacement bearings in some patients, which have been associated with edge loading of the head on the rim of the cup. We have simulated increased wear and ion levels in metal-on-metal bearings in vitro by introducing variations in translational and rotational positioning of the components, which reproduces stripe wear on the femoral head, cup rim wear and clinically relevant large as well as small wear particles. There is interest in technologies such as surface engineering, which might reduce metal wear and the release of wear particles and ions. Reduced wear with surface-engineered surface replacements compared to metal-on-metal controls has been reported under standard walking conditions with correctly aligned and concentric components. In this in vitro study, the wear of chromium nitride surface-engineered metal-on-metal bearings under conditions of microseparation associated with translational and rotational malpositioning of the components was investigated and the results were compared with a previously reported study of metal-on-metal bearings under the same conditions. Simulations were conducted using our unique hip simulation microseparation methodologies, which reproduce accelerated wear in metal-on-metal bearings and have previously been clinically validated with ceramic-on-ceramic bearings. Four of the six surface-engineered bearings had evidence of head contact on the rim of the cup, which produced stripe wear on the femoral head. Four of the six surface-engineered bearings (two without stripe and two with stripe wear) had lower wear than the previously reported high wearing metal-on-metal bearings. At 2 million cycles, two of the surface-engineered bearings had substantially increased wear rates, four times higher than the high wear rates previously reported for metal-on-metal bearings under the same conditions. There was

  8. Prediction of contact mechanics in metal-on-metal Total Hip Replacement for parametrically comprehensive designs and loads.

    PubMed

    Donaldson, Finn E; Nyman, Edward; Coburn, James C

    2015-07-16

    Manufacturers and investigators of Total Hip Replacement (THR) bearings require tools to predict the contact mechanics resulting from diverse design and loading parameters. This study provides contact mechanics solutions for metal-on-metal (MoM) bearings that encompass the current design space and could aid pre-clinical design optimization and evaluation. Stochastic finite element (FE) simulation was used to calculate the head-on-cup contact mechanics for five thousand combinations of design and loading parameters. FE results were used to train a Random Forest (RF) surrogate model to rapidly predict the contact patch dimensions, contact area, pressures and plastic deformations for arbitrary designs and loading. In addition to widely observed polar and edge contact, FE results included ring-polar, asymmetric-polar, and transitional categories which have previously received limited attention. Combinations of design and load parameters associated with each contact category were identified. Polar contact pressures were predicted in the range of 0-200 MPa with no permanent deformation. Edge loading (with subluxation) was associated with pressures greater than 500 MPa and induced permanent deformation in 83% of cases. Transitional-edge contact (with little subluxation) was associated with intermediate pressures and permanent deformation in most cases, indicating that, even with ideal anatomical alignment, bearings may face extreme wear challenges. Surrogate models were able to accurately predict contact mechanics 18,000 times faster than FE analyses. The developed surrogate models enable rapid prediction of MoM bearing contact mechanics across the most comprehensive range of loading and designs to date, and may be useful to those performing bearing design optimization or evaluation.

  9. Hip Resurfacing: An Alternative to Conventional Hip Replacement?

    MedlinePlus

    ... bone is reshaped and capped with a metal prosthesis. The hip socket is fitted with a metal ... but higher levels may be problematic. The socket prosthesis for a traditional hip replacement is usually lined ...

  10. Groin pain following hip resurfacing: a case-control study.

    PubMed

    McArthur, John R; Costa, Matthew; Griffin, Damian R; Krikler, Steven J; Parsons, Nicholas; Foguet, Pedro R

    2011-01-01

    We compared 47 patients with groin pain following hip resurfacing to a matched control group. Functional scores and plain radiographs were assessed along with measurement of whole blood cobalt and chromium by inductively coupled mass spectrometry. Symptomatic patients underwent ultrasound scan of the affected hip. Mean functional outcomes were poor in those with pain and good in the control group. Groin pain was associated with valgus stem positioning and lower neck:head ratio (relatively narrow neck) (p=0.03, p=0.04 respectively). We classified patients with groin pain into two groups: biological and mechanical. The biological group had soft tissue abnormalities on USS and higher levels of cobalt and chromium (p=0.04, p=0.05 respectively). The mechanical group had normal USS, lower metal ion levels and more retroverted femoral components (p=0.01).

  11. High incidence of pseudotumours after hip resurfacing even in low risk patients; results from an intensified MRI screening protocol.

    PubMed

    van der Weegen, Walter; Smolders, Jose M H; Sijbesma, Thea; Hoekstra, Henk J; Brakel, Koen; van Susante, Job L C

    2013-01-01

    We intensified our screening protocol for the presence of pseudotumours in a consecutive series of patients with a hip resurfacing arthroplasty (HRA), to establish whether we should be alert to the presence of 'silent' pseudotumours. Patients categorised with high risk (11 hips) and low risk (10 hips) for pseudotumour development and a control group (23 hips) were screened with metal artefact reduction sequence (MARS) magnetic resonance imaging (MRI). The Anderson classification to grade any metal-on-metal (MoM) disease present on MARS-MRI images was used. In 15 out of 44 MRI scans pseudotumours were observed (34.1%), of which six were graded with mild (13.6%), eight with moderate (18.2%) and one with severe MoM disease (2.3%). Twelve pseudotumours were present in asymptomatic patients (27.3%). Metal ion levels were normal in 80% of the MARS-MRI screened patients. As a consequence of our intensified screening protocol, one patient was revised for pseudotumour formation and another patient was scheduled for revision. Silent pseudotumours were observed in all three groups. Before our intensified screening protocol was initiated, no pseudotumours were encountered in our cohort of 289 HRAs. We concluded that clinical outcomes and plain radiographs for screening MoM patients underestimates the presence of pseudotumours in MoM patients. The true clinical relevance of these pseudotumours is still unclear.

  12. N-Acetyl-Cysteine as Effective and Safe Chelating Agent in Metal-on-Metal Hip-Implanted Patients: Two Cases

    PubMed Central

    Lonati, Davide; Ragghianti, Benedetta; Ronchi, Anna; Vecchio, Sarah; Locatelli, Carlo Alessandro

    2016-01-01

    Systemic toxicity associated with cobalt (Co) and chromium (Cr) containing metal hip alloy may result in neuropathy, cardiomyopathy, and hypothyroidism. However clinical management concerning chelating therapy is still debated in literature. Here are described two metal-on-metal hip-implanted patients in which N-acetyl-cysteine decreased elevated blood metal levels. A 67-year-old male who underwent Co/Cr hip implant in September 2009 referred to our Poison Control Centre for persisting elevated Co/Cr blood levels (from March 2012 to November 2014). After receiving oral high-dose N-acetyl-cysteine, Co/Cr blood concentrations dropped by 86% and 87% of the prechelation levels, respectively, and persisted at these latter concentrations during the following 6 months of follow-up. An 81-year-old female who underwent Co/Cr hip implant in January 2007 referred to our Centre for detection of high Co and Cr blood levels in June 2012. No hip revision was indicated. After a therapy with oral high-dose N-acetyl-cysteine Co/Cr blood concentrations decreased of 45% and 24% of the prechelation levels. Chelating agents reported in hip-implanted patients (EDTA, DMPS, and BAL) are described in few cases. N-acetyl-cysteine may provide chelating sites for metals and in our cases reduced Co and Cr blood levels and resulted well tolerable. PMID:27148463

  13. Distributed Analysis of Hip Implants Using Six National and Regional Registries: Comparing Metal-on-Metal with Metal-on-Highly Cross-Linked Polyethylene Bearings in Cementless Total Hip Arthroplasty in Young Patients

    PubMed Central

    Furnes, Ove; Paxton, Elizabeth; Cafri, Guy; Graves, Stephen; Bordini, Barbara; Comfort, Thomas; Rivas, Moises Coll; Banerjee, Samprit; Sedrakyan, Art

    2014-01-01

    Background: The regulation of medical devices has attracted controversy recently because of problems related to metal-on-metal hip implants. There is growing evidence that metal-on-metal implants fail early and cause local and systemic complications. However, the failure associated with metal-on-metal head size is not consistently documented and needs to be communicated to patients and surgeons. The purpose of this study is to compare implant survival of metal on metal with that of metal on highly cross-linked polyethylene. Methods: Using a distributed health data network, primary total hip arthroplasties were identified from six national and regional total joint arthroplasty registries (2001 to 2010). Inclusion criteria were patient age of forty-five to sixty-four years, cementless total hip arthroplasties, primary osteoarthritis diagnosis, and exclusion of the well-known outlier implant ASR (articular surface replacement). The primary outcome was revision for any reason. A meta-analysis of survival probabilities was performed with use of a fixed-effects model. Metal-on-metal implants with a large head size of >36 mm were compared with metal-on-highly cross-linked polyethylene implants. Results: Metal-on-metal implants with a large head size of >36 mm were used in 5172 hips and metal-on-highly cross-linked polyethylene implants were used in 14,372 hips. Metal-on-metal total hip replacements with a large head size of >36 mm had an increased risk of revision compared with metal-on-highly cross-linked polyethylene total hip replacements with more than two years of follow-up, with no difference during the first two years after implantation. The results of the hazard ratios (and 95% confidence intervals) from the multivariable model at various durations of follow-up were 0.95 (0.74 to 1.23) at zero to two years (p = 0.698), 1.42 (1.16 to 1.75) at more than two years to four years (p = 0.001), 1.78 (1.45 to 2.19) at more than four years to six years (p < 0.001), and 2

  14. Hip resurfacing after iliofemoral distraction for type IV developmental dysplasia of the hip a case report.

    PubMed

    Sambri, A; Cadossi, M; Mazzotti, A; Faldini, C; Giannini, S

    2015-01-01

    Osteoarthritis secondary to developmental dysplasia of the hip is a surgical challenge because of the modified anatomy of the acetabulum which is deficient in its shape with poor bone quality, torsional deformities of the femur and the altered morphology of femoral head. Particularly in Crowe type III and IV, additional surgical challenges are present, such as limb-length discrepancy and adductor muscle contractures. This is a bilateral hip dysplasia case where bilateral hip replacement was indicated, on the left side with a resurfacing one and on the other side a two stage procedure using a iliofemoral external fixator to restore equal leg length with a lower risk of complications. This case report shows both the negative clinical outcome of the left and the excellent one of the right hip where the dysplasia was much more severe. Patient selection and implant positioning are crucial in determining long-term results.

  15. Complications Related to Metal-on-Metal Articulation in Trapeziometacarpal Joint Total Joint Arthroplasty

    PubMed Central

    Frølich, Christina; Hansen, Torben Bæk

    2015-01-01

    Adverse reactions to metal-on-metal (MoM) prostheses are well known from total hip joint resurfacing arthroplasty with elevated serum chrome or cobalt, pain and pseudo tumor formation. It may, however, also be seen after total joint replacement of the trapeziometacarpal joint using MoM articulation, and we present two cases of failure of MoM prostheses due to elevated metal-serum levels in one case and pseudo tumor formation in another case. Furthermore, we suggest a diagnostic algorithm for joint pain after MoM trapeziometacarpal joint replacement based on published experiences from MoM hip prostheses and adverse reactions to metal. PMID:26020592

  16. Validation of primary metal-on-metal hip arthroplasties on the National Joint Registry for England, Wales and Northern Ireland using data from the London Implant Retrieval Centre

    PubMed Central

    Sabah, S. A.; Henckel, J.; Cook, E.; Whittaker, R.; Hothi, H.; Pappas, Y.; Blunn, G.; Skinner, J. A.; Hart, A. J.

    2015-01-01

    Arthroplasty registries are important for the surveillance of joint replacements and the evaluation of outcome. Independent validation of registry data ensures high quality. The ability for orthopaedic implant retrieval centres to validate registry data is not known. We analysed data from the National Joint Registry for England, Wales and Northern Ireland (NJR) for primary metal-on-metal hip arthroplasties performed between 2003 and 2013. Records were linked to the London Implant Retrieval Centre (RC) for validation. A total of 67 045 procedures on the NJR and 782 revised pairs of components from the RC were included. We were able to link 476 procedures (60.9%) recorded with the RC to the NJR successfully. However, 306 procedures (39.1%) could not be linked. The outcome recorded by the NJR (as either revised, unrevised or death) for a primary procedure was incorrect in 79 linked cases (16.6%). The rate of registry-retrieval linkage and correct assignment of outcome code improved over time. The rates of error for component reference numbers on the NJR were as follows: femoral head category number 14/229 (5.0%); femoral head batch number 13/232 (5.3%); acetabular component category number 2/293 (0.7%) and acetabular component batch number 24/347 (6.5%). Registry-retrieval linkage provided a novel means for the validation of data, particularly for component fields. This study suggests that NJR reports may underestimate rates of revision for many types of metal-on-metal hip replacement. This is topical given the increasing scope for NJR data. We recommend a system for continuous independent evaluation of the quality and validity of NJR data. Cite this article: Bone Joint J 2015;97-B:10–18. PMID:25568407

  17. Hip resurfacing arthroplasty: A new method to assess and quantify learning phase.

    PubMed

    Aulakh, T S; Jayasekera, N; Singh, R; Patel, A; Kuiper, J H; Richardson, J B

    2014-09-01

    Hip resurfacing had initially gained acceptance and popularity as it helps preserve femoral bone stock. In this study we tried to answer the following questions; 1. Whether there is a learning curve for hip resurfacing? 2. Is it present in surgeons from non-developer centres? 3. Is it present in surgeons from developer centres as well? The Oswestry outcome centre was setup to serve an independent international registry for collecting, analysing and reporting outcomes following hip resurfacing. Over a 10 year period, 4535 patients (5000 hips) were recruited from different countries and within the UK from different centres in this study by 139 surgeons from 37 different countries. Our study has shown that function can be used to assess the level of surgical competence. The results from this multilevel analysis have helped to answer the questions posed in the introduction. Hip resurfacing is a surgical procedure with a learning phase and this learning effect is more pronounced in non-developer surgeons as compared to developer surgeons. Hip scores can be used to assess proficiency and competence of surgeons undertaking hip resurfacing arthroplasty.

  18. Gluteal muscle fatty atrophy is not associated with elevated blood metal ions or pseudotumors in patients with a unilateral metal-on-metal hip replacement

    PubMed Central

    Reito, Aleksi; Elo, Petra; Nieminen, Jyrki; Puolakka, Timo; Eskelinen, Antti

    2016-01-01

    Background and purpose There are no international guidelines to define adverse reaction to metal debris (ARMD). Muscle fatty atrophy has been reported to be common in patients with failing metal-on-metal (MoM) hip replacements. We assessed whether gluteal muscle fatty atrophy is associated with elevated blood metal ion levels and pseudotumors. Patients and methods 263 consecutive patients with unilateral ASR XL total hip replacement using a posterior approach and with an unoperated contralateral hip were included in the study. All patients had undergone a standard screening program at our institution, including MRI and blood metal ion measurement. Muscle fatty atrophy was graded as being absent, mild, moderate, or severe in each of the gluteal muscles. Results The prevalance of moderate-to-severe gluteal muscle atrophy was low (12% for gluteus minimus, 10% for gluteus medius, and 2% for gluteus maximus). Muscle atrophy was neither associated with elevated blood metal ion levels (> 5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI. A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare. Multivariable regression revealed that “preoperative diagnosis other than osteoarthrosis” was the strongest predictor of the presence of fatty atrophy. Interpretation Gluteal muscle atrophy may be a clinically significant finding with influence on hip muscle strength in patients with MoM hip replacement. However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach. PMID:26427902

  19. Clinical Usefulness of SPECT-CT in Patients with an Unexplained Pain in Metal on Metal (MOM) Total Hip Arthroplasty.

    PubMed

    Berber, Reshid; Henckel, Johann; Khoo, Michael; Wan, Simon; Hua, Jia; Skinner, John; Hart, Alister

    2015-04-01

    SPECT-CT is increasingly used to assess painful knee arthroplasties. The aim of this study was to evaluate the clinical usefulness of SPECT-CT in unexplained painful MOM hip arthroplasty. We compared the diagnosis and management plan for 19 prosthetic MOM hips in 15 subjects with unexplained pain before and after SPECT-CT. SPECT-CT changed the management decision in 13 (68%) subjects, Chi-Square=5.49, P=0.24. In 6 subjects (32%) pain remained unexplained however the result reassured the surgeon to continue with non-operative management. SPECT-CT should be reserved as a specialist test to help identify possible causes of pain where conventional investigations have failed. It can help reassure surgeons making management decisions for patients with unexplained pain following MOM hip arthroplasty.

  20. Serial magnetic resonance imaging of metal-on-metal total hip replacements. Follow-up of a cohort of 28 mm Ultima TPS THRs.

    PubMed

    Ebreo, D; Bell, P J; Arshad, H; Donell, S T; Toms, A; Nolan, J F

    2013-08-01

    Metal artefact reduction (MAR) MRI is now widely considered to be the standard for imaging metal-on-metal (MoM) hip implants. The Medicines and Healthcare Products Regulatory Agency (MHRA) has recommended cross-sectional imaging for all patients with symptomatic MoM bearings. This paper describes the natural history of MoM disease in a 28 mm MoM total hip replacement (THR) using MAR MRI. Inclusion criteria were patients with MoM THRs who had not been revised and had at least two serial MAR MRI scans. All examinations were reported by an experienced observer and classified as A (normal), B (infection) or C1-C3 (mild, moderate, severe MoM-related abnormalities). Between 2002 and 2011 a total of 239 MRIs were performed on 80 patients (two to four scans per THR); 63 initial MRIs (61%) were normal. On subsequent MRIs, six initially normal scans (9.5%) showed progression to a disease state; 15 (15%) of 103 THRs with sequential scans demonstrated worsening disease on subsequent imaging. Most patients with a MoM THR who do not undergo early revision have normal MRI scans. Late progression (from normal to abnormal, or from mild to more severe MoM disease) is not common and takes place over several years.

  1. Predictors of femoral neck fracture following hip resurfacing: a cadaveric study.

    PubMed

    Davis, Edward T; Olsen, Michael; Zdero, Rad; Smith, Gemma M; Waddell, James P; Schemitsch, Emil H

    2013-01-01

    We aimed to establish if radiological parameters, dual energy x-ray absorptiometry (DEXA) and quantitative CT (qCT) could predict the risk of sustaining a femoral neck fracture following hip resurfacing. Twenty-one unilateral fresh frozen femurs were used. Each femur had a plain digital anteroposterior radiograph, DEXA scan and qCT scan. Femurs were then prepared for a Birmingham Hip Resurfacing femoral component and loaded to failure. Results demonstrated that gender and qCT measurements showed strong correlation with failure load. QCT could be used as an individual measure to predict risk of post-operative femoral neck fracture. However, when qCT is unavailable; gender, pre-operative DEXA scan and Neck Width measurements can be used together to assess risk of post-operative femoral neck fracture in patients due to undergo hip resurfacing.

  2. Differential distribution of cobalt, chromium, and nickel between whole blood, plasma and urine in patients after metal-on-metal (MoM) hip arthroplasty.

    PubMed

    Newton, Ashley W; Ranganath, Lakshminarayan; Armstrong, Catherine; Peter, Viju; Roberts, Norman B

    2012-10-01

    Evidence shows that raised cobalt (Co), chromium (Cr), and nickel (Ni) whole blood concentrations correlate with poor device outcome in patients following metal-on-metal (MoM) hip arthroplasty. To understand the local and systemic pathological effects of these raised metal concentrations it is important to define their distribution between whole blood, plasma, and urine. The metals were measured by Inductively Coupled Plasma Mass Spectrometry (ICPMS). Two hundred and five plasma, 199 whole blood, and 24 sets of urine samples were analyzed from 202 patients with Co-Cr alloy MoM hip prostheses implanted between 8 months to 12 years (mean 6.0 years) prior to analysis. Plasma Co (median 39.1 nmol/L) showed significantly positive 1:1 correlation with whole blood Co (median 45.9 nmol/L; R(2)  = 0.98, p < 0.001, slope = 1.0). Plasma Cr (median 53.8 nmol/L) and whole blood Cr (median 40.3 nmol/L) were also correlated; however, concentrations were significantly higher in plasma indicating relatively little blood cell uptake (R(2)  = 0.96, p < 0.001, slope = 1.6). Urinary Co was up to threefold higher than Cr (median 334.0 vs. 97.3 nmol/L respectively). Nickel concentrations in whole blood, plasma, and urine were low relative to Co and Cr. The analysis shows fundamental differences in the physiological handling of these metals: Co is distributed approximately equally between blood cells and plasma, whereas Cr is mainly in plasma, despite which, Cr had far less renal excretion than Co.

  3. Effect of head size on wear properties of metal-on-metal bearings of hip prostheses, and comparison with wear properties of metal-on-polyethylene bearings using hip simulator.

    PubMed

    Okazaki, Yoshimitsu

    2014-03-01

    The effects of articular head size on the wear losses of the metal insert and articular head for a metal-on-metal bearing were examined using a hip simulator manufactured to satisfy ISO 14242-1. The wear properties of metal-on-metal and metal-on-polyethylene bearings were also compared under the same conditions. The total wear losses of the metal insert and articular head decreased with increasing diameter of the metal insert in the range from 28 to 44mm. The total wear loss was greater for a diameter of 48mm than for a diameter of 44mm. When the articular metal insert diameter was smaller than 44mm, the wear loss was reduced because the contact surface pressure increased with increasing metal insert diameter. However, the increase in wear loss observed for the 48-mm-diameter insert might have been due to the considerable increase in the rotation moment with increasing insert diameter. The tendency of decreasing contact pressure calculated using the Hertzian contact stress equation nearly conformed to the change in wear loss. On the other hand, the wear loss of an artificial hip joint consisting of a cross-linked ultrahigh-molecular-weight polyethylene insert (UHMWPE) and a Co-Cr-Mo articular head was small.

  4. Lubrication of metal-on-metal hip joints: the effect of protein content and load on film formation and wear.

    PubMed

    Myant, C; Underwood, R; Fan, J; Cann, P M

    2012-02-01

    Lubricant films were measured for a series of bovine serum and protein containing (albumin, globulin) saline solutions for CoCrMo femoral component sliding against a glass disc. Central film thickness was measured by optical interferometry as a function of time (constant mean speed: 0 and 10 mm/s) and variable mean speed (0-50 mm/s). The effect of load (5-20 N) on film thickness was also studied. The development of the wear scar on the CoCrMo surface was monitored by measuring the width of the contact zone during the film thickness tests. The results showed film thickness increased with time for both the static and sliding tests. Films formed in the static, loaded test were typically in the range of 3-40 nm. The globulin containing solutions formed the thickest films. In the sliding tests a wear scar rapidly formed on the implant component for the bovine serum and albumin fluids, negligible wear was observed for the globulin solutions. Film thickness increased with sliding time for all test solutions and was much greater than predicted by isoviscous EHL models. The film increase was found to correlate with increasing wear scar size and thus decreasing contact pressure. A new lubricating mechanism is proposed whereby during sliding the fluid undergoes bulk phase separation rheology, so that an elevated protein phase forms in the inlet zone. This protein phase is a high-viscosity biphasic matrix, which is periodically entrained into the contact forming a thick protective hydro-gel film. One of the main findings of this study is that film thickness was very sensitive to load; to a much greater extent than predicted by EHL models. Thus film formation in MoM hip joints is very susceptible to high contact pressures which might be due to implant misalignment and edge-loading.

  5. CoCr wear particles generated from CoCr alloy metal-on-metal hip replacements, and cobalt ions stimulate apoptosis and expression of general toxicology-related genes in monocyte-like U937 cells

    SciTech Connect

    Posada, Olga M.; Gilmour, Denise; Tate, Rothwelle J.; Grant, M. Helen

    2014-11-15

    Cobalt-chromium (CoCr) particles in the nanometre size range and their concomitant release of Co and Cr ions into the patients' circulation are produced by wear at the articulating surfaces of metal-on-metal (MoM) implants. This process is associated with inflammation, bone loss and implant loosening and led to the withdrawal from the market of the DePuy ASR™ MoM hip replacements in 2010. Ions released from CoCr particles derived from a resurfacing implant in vitro and their subsequent cellular up-take were measured by ICP-MS. Moreover, the ability of such metal debris and Co ions to induce both apoptosis was evaluated with both FACS and immunoblotting. qRT-PCR was used to assess the effects on the expression of lymphotoxin alpha (LTA), BCL2-associated athanogene (BAG1), nitric oxide synthase 2 inducible (NOS2), FBJ murine osteosarcoma viral oncogene homolog (FOS), growth arrest and DNA-damage-inducible alpha (GADD45A). ICP-MS showed that the wear debris released significant (p < 0.05) amounts of Co and Cr ions into the culture medium, and significant (p < 0.05) cellular uptake of both ions. There was also an increase (p < 0.05) in apoptosis after a 48 h exposure to wear debris. Analysis of qRT-PCR results found significant up-regulation (p < 0.05) particularly of NOS2 and BAG1 in Co pre-treated cells which were subsequently exposed to Co ions + debris. Metal debris was more effective as an inducer of apoptosis and gene expression when cells had been pre-treated with Co ions. This suggests that if a patient receives sequential bilateral CoCr implants, the second implant may be more likely to produce adverse effects than the first one. - Highlights: • Effects of CoCr nanoparticles and Co ions on U937 cells were investigated. • Ions released from wear debris play an important role in cellular response, • Toxicity of Co ions could be related to NO metabolic processes and apoptosis. • CoCr particles were a more effective inducer of apoptosis after cell

  6. Effect of femoral head size on the wear of metal on metal bearings in total hip replacements under adverse edge-loading conditions.

    PubMed

    Al-Hajjar, Mazen; Fisher, John; Williams, Sophie; Tipper, Joanne L; Jennings, Louise M

    2013-02-01

    Metal-on-metal (MoM) bearings have shown low-wear rates under standard hip simulator conditions; however, retrieval studies have shown large variations in wear rates and mechanisms. High-wear in vivo has caused catastrophic complications and has been associated with steep cup-inclination angle (rotational malpositioning). However, increasing the cup-inclination angle in vitro has not replicated the increases in wear to the same extent as those observed in retrievals. Clinically relevant wear rates, patterns, and particles were observed in vitro for ceramic-on-ceramic bearings when microseparation (translational malpositioning) conditions were introduced into the gait cycle. In the present study, 28 and 36-mm MoM bearings were investigated under adverse conditions. Increasing the cup angle from 45° to 65° resulted in a significant increase in the wear rate of the 28 mm bearings. However, for the 36 mm bearings, head-rim contact did not occur under the steep cup-angle condition, and the wear rate did not increase. The introduction of microseparation to the gait cycle significantly increased the wear rate of the MoM bearings. Cup angle and head size did not influence the wear rate under microseparation conditions. This study indicated that high-in vivo wear rates were associated with edge loading due to rotational malpositioning such as high-cup-inclination angle and translational malpositioning that could occur due to several surgical factors. Translational malpositioning had a more dominant effect on the wear rate. Preclinical simulation testing should be undertaken with translational and rotational malpositioning conditions as well as standard walking cycle conditions defined by the ISO standard.

  7. Highly cross-linked polyethylene in hip resurfacing arthroplasty: long-term follow-up.

    PubMed

    Amstutz, Harlan C; Takamura, Karren M; Ebramzadeh, Edward; Le Duff, Michel J

    2015-01-01

    Highly cross-linked polyethylene (XLPE) has improved wear properties. This study reports the results of a small series of patients treated over 10 years ago with a metal-on-XLPE hip resurfacing.A total of 21 hips in 20 patients received a hip resurfacing with a cobalt-chromium metal femoral head and metal-backed acetabular cup lined with a XLPE insert and were retrospectively studied. Kaplan-Meier Survivorship was calculated.Five patients who had initial extreme cystic disease in the femoral head failed due to femoral loosening. Survivorship was 95.2% at 5 years and 81.0% at 10 years.We found that XLPE wear was not implicated in these failures, which were primarily attributed to poor bone quality of the femoral head, early bone preparation, cementing technique and excessive head reaming to near the neck diameter, necessitated for the implantation of a thick two-part socket.

  8. 21 CFR 888.3410 - Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hip joint metal/polymer or ceramic/polymer... Devices § 888.3410 Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis. (a) Identification. A hip joint metal/polymer or ceramic/polymer semi-constrained...

  9. 21 CFR 888.3410 - Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hip joint metal/polymer or ceramic/polymer... Devices § 888.3410 Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis. (a) Identification. A hip joint metal/polymer or ceramic/polymer semi-constrained...

  10. 21 CFR 888.3410 - Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hip joint metal/polymer or ceramic/polymer... Devices § 888.3410 Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis. (a) Identification. A hip joint metal/polymer or ceramic/polymer semi-constrained...

  11. 21 CFR 888.3410 - Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/polymer or ceramic/polymer... Devices § 888.3410 Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis. (a) Identification. A hip joint metal/polymer or ceramic/polymer semi-constrained...

  12. 21 CFR 888.3410 - Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint metal/polymer or ceramic/polymer... Devices § 888.3410 Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis. (a) Identification. A hip joint metal/polymer or ceramic/polymer semi-constrained...

  13. Outcomes of hip resurfacing in a professional dancer: a case report.

    PubMed

    Dunleavy, Kim

    2012-02-01

    A new surgical option (hip resurfacing arthroplasty) is now available for younger patients with hip osteoarthritis. A more aggressive rehabilitation program than the typical total hip arthroplasty protocol is needed for active individuals. This case report describes interventions used to maximize function in a 46-year-old professional dancer after hip resurfacing with a progressive therapeutic exercise program. Exercise choices were selected to address dance-specific requirements while respecting healing of the posterior capsular incision. Strengthening focused on hip abduction, extension, and external rotation. Precautions included avoiding gluteal stretching until 6 months. Pelvic alignment and weight-bearing distribution were emphasized. The patient was able to return to rehearsal by 7 months, at which time strength was equivalent to the unaffected leg. Range of motion reached unaffected side values at week 8 for internal rotation, week 11 for extension, week 13 for adduction, and week 28 for flexion. External rotation and abduction were still limited at 1 year, which influenced pelvic alignment with resultant pain on the unaffected side. Functional and impairment outcomes are presented with timelines to provide a basis for postoperative benchmarks for active clients after hip resurfacing. Although this case report presents a dance-specific program, exercise progressions for other active individuals may benefit from similar exercise intensity and sports-specific focus. Future rehabilitation programs should take into account possible flexion and external rotation range limitations and the need for gluteal muscle strengthening along with symmetry and pelvic alignment correction. Long-term studies investigating intensity of rehabilitation are warranted for patients intending to participate in higher level athletic activity.

  14. Partial hemi-resurfacing of the hip joint--a new approach to treat local osteochondral defects?

    PubMed

    Jäger, Marcus; Begg, Malcom J W; Krauspe, Rüdiger

    2006-12-01

    There is currently renewed interest in articular resurfacing for the treatment of damaged hip-joint cartilage. In contrast to these implants, which involve endoprosthetic replacement of both articulating surfaces, we present a new joint-preserving technique that allows treatment of local osteochondral defects of the femoral head by partial hemi-resurfacing. In this study we describe the operative and technical aspects and problems for partial hemi-resurfacing of the hip joint and critically discuss indications for this procedure in one case. To guarantee an adequate view of the situs, we recommend a surgical approach involving trochanter flip osteotomy, followed by surgical dislocation of the hip joint. Besides partial hemi-resurfacing of the osteochondral defect, this approach allows treatment of associated labral tears and cartilage defects of the hip joint at the same time. For adequate implant fixation, good bone quality is required. Furthermore, osteochondral defects of limited extent and excellent patient compliance are essential for clinical success. In particular, prominence of the implant has to be avoided, which can lead to an irregular joint surface and may induce further cartilage destruction. Long-term studies on statistical populations will show if partial articular hemi-resurfacing is a bone-preserving and useful therapeutic alternative to hemi-resurfacing caps in the treatment of osteochondral hip-joint defects, especially in young patients.

  15. Comparison of Whole-Blood Metal Ion Levels Among Four Types of Large-Head, Metal-on-Metal Total Hip Arthroplasty Implants: A Concise Follow-up, at Five Years, of a Previous Report.

    PubMed

    Hutt, Jonathan; Lavigne, Martin; Lungu, Eugen; Belzile, Etienne; Morin, François; Vendittoli, Pascal-André

    2016-02-17

    Few studies of total hip arthroplasty (THA) implants with a large-diameter femoral head and metal-on-metal design have directly compared the progression of metal ion levels over time and the relationship to complications. As we previously reported, 144 patients received one of four types of large-diameter-head, metal-on-metal THA designs (Durom, Birmingham, ASR XL, or Magnum implants). Cobalt, chromium, and titanium ion levels were measured over five years. We compared ion levels and clinical results over time. The Durom group showed the highest levels of cobalt (p ≤ 0.002) and titanium ions (p ≤ 0.03). Both the Durom and Birmingham groups demonstrated significant ongoing cobalt increases up to five years. Eight patients (seven with a Durom implant and one with a Birmingham implant) developed adverse local tissue reaction. Six Durom implants and one Birmingham implant required revision, with one pseudotumor under surveillance at the time of the most recent follow-up. We found that ion generation and related complications varied among designs. More concerning was that, for some designs, ion levels continued to increase. Coupling a cobalt-chromium adapter sleeve to an unmodified titanium femoral trunnion along with a large metal-on-metal bearing may explain the poor performances of two of the designs in the current study.

  16. The clinical implications of elevated blood metal ion concentrations in asymptomatic patients with MoM hip resurfacings: a cohort study

    PubMed Central

    Langton, David J; Sidaginamale, Raghavendra P; Joyce, Thomas J; Natu, Shonali; Blain, Peter; Jefferson, Robert Drysdale; Rushton, Stephen; Nargol, Antoni V F

    2013-01-01

    Objective To determine whether elevated blood cobalt (Co) concentrations are associated with early failure of metal-on-metal (MoM) hip resurfacings secondary to adverse reaction to metal debris (ARMD). Design Cohort study. Setting Single centre orthopaedic unit. Participants Following the identification of complications potentially related to metal wear debris, a blood metal ion screening programme was instigated at our unit in 2007 for all patients with Articular Surface Replacement (ASR) and Birmingham MoM hip resurfacings. Patients were followed annually unless symptoms presented earlier. Symptomatic patients were investigated with ultrasound scan and joint aspiration. The clinical course of all 278 patients with ‘no pain’ or ‘slight/occasional’ pain and a Harris Hip Score greater than or equal to 95 at the time of venesection were documented. A retrospective analysis was subsequently conducted using mixed effect modelling to investigate the temporal pattern of blood Co levels in the patients and survival analysis to investigate the potential role of case demographics and blood Co levels as risk factors for subsequent failure secondary to ARMD. Results Blood Co concentration was a positive and significant risk factor (z=8.44, p=2×10–16) for joint failure, as was the device, where the Birmingham Hip Resurfacing posed a significantly reduced risk for revision by 89% (z=−3.445, p=0.00005 (95% CI on risk 62 to 97)). Analysis using Cox-proportional hazards models indicated that men had a 66% lower risk of joint failure than women (z=−2.29419, p=0.0218, (95% CI on risk reduction 23 to 89)). Conclusions The results suggest that elevated blood metal ion concentrations are associated with early failure of MoM devices secondary to adverse reactions to metal debris. Co concentrations greater than 20 µg/l are frequently associated with metal staining of tissues and the development of osteolysis. Development of soft tissue damage appears to be more complex

  17. The immunobiology of cobalt: demonstration of a potential aetiology for inflammatory pseudotumours after metal-on-metal replacement of the hip.

    PubMed

    Lawrence, H; Deehan, D; Holland, J; Kirby, J; Tyson-Capper, A

    2014-09-01

    Abnormal wear of cobalt-containing metal-on-metal joints is associated with inflammatory pseudotumours. Cobalt ions activate human toll-like receptor 4 (TLR4), which normally responds to bacterial lipopolysaccharide (LPS) in sepsis. Activation of TLR4 by LPS increases the expression of chemokines IL-8 and CXCL10, which recruit leukocytes and activated T-cells, respectively. This study was designed to determine whether cobalt induces a similar inflammatory response to LPS by promoting the expression of IL-8 and CXCL10. A human monocytic cell line, derived from acute monocytic leukaemia, was treated with cobalt ions and expression of IL-8 and CXCL10 measured at mRNA and protein levels. Cobalt-treated macrophages showed a 60-fold increase in IL-8 mRNA, and an eightfold increase in production of the mature chemokine (both p < 0.001); expression of the CXCL10 gene and protein was also significantly increased by cobalt (both p < 0.001). Experiments were also performed in the presence of CLI-095, a TLR4-specific antagonist which abrogated the cobalt-mediated increase in IL-8 and CXCL10 expression. These findings suggest that cobalt ions induce inflammation similar to that observed during sepsis by the simultaneous activation of two TLR4-mediated signalling pathways. These pathways result in increased production of IL-8 and CXCL10, and may be implicated in pseudotumour formation following metal-on-metal replacement.

  18. Periacetabular bone mineral density changes after resurfacing hip arthroplasty versus conventional total hip arthroplasty. A randomized controlled DEXA study.

    PubMed

    Smolders, José M H; Pakvis, Dean F; Hendrickx, Baudewijn W; Verdonschot, Nico; van Susante, Job L C

    2013-08-01

    A randomized controlled trial was performed to evaluate acetabular bone mineral density (BMD) changes after hip resurfacing (RHA) versus an established conventional total hip arthroplasty (THA). A total of 71 patients were allocated randomly to receive either an RHA press-fit cobalt-chromium cup (n=38) or a THA with a threaded titanium cup and polyethylene-metal-inlay insert (n=33). The BMD in five separate periacetabular regions of interest (ROI) was prospectively quantified preoperative until 24 months. We conclude that, in contrast to our hypothesis, periacetabular BMD was better preserved after RHA than after placement of a conventional THA. Long term follow-up studies are necessary to see whether this benefit in bone preservation sustains over longer time periods and whether it is turned into clinical benefits at future revision surgery.

  19. Simple isolation method for the bulk isolation of wear particles from metal on metal bearing surfaces generated in a hip simulator test.

    PubMed

    Lu, Fang; Royle, Matt; Lali, Ferdinand V; Hart, Alister J; Collins, Simon; Housden, Jonathan; Shelton, Julia C

    2012-04-01

    Isolation and characterization of metal-on-metal (MoM) wear particles from simulator lubricants is essential to understand wear behaviour, ion release and associated corrosive activity related to the wear particles. Substantial challenges remain to establish a simple, precise and repeatable protocol for the isolation and analysis of wear particles due to their extremely small size, their tendency to agglomerate and degrade. In this paper, we describe a simple and efficient method for the bulk isolation and characterisation of wear particles from MoM bearings. Freeze drying was used to remove the large volume of water from the serum lubricant, enzymes used to digest the proteins and ultracentrifugation to finally isolate and purify the particles. The present study involved a total of eight steps for the isolation process and a wear particle extraction efficiency of 45% was achieved.

  20. A Two Centre Study to Assess the Long-term Performance of the Pinnacle™ Cup With a Metal-on-Metal Bearing in Primary Total Hip Replacement

    ClinicalTrials.gov

    2016-10-06

    Rheumatoid Arthritis; Osteoarthritis; Post-traumatic Arthritis; Collagen Disorders; Avascular Necrosis; Traumatic Femoral Fractures; Nonunion of Femoral Fractures; Congenital Hip Dysplasia; Slipped Capital Femoral Epiphysis

  1. Toxicology of wear particles of cobalt-chromium alloy metal-on-metal hip implants Part II: Importance of physicochemical properties and dose in animal and in vitro studies as a basis for risk assessment.

    PubMed

    Madl, Amy K; Kovochich, Michael; Liong, Monty; Finley, Brent L; Paustenbach, Dennis J; Oberdörster, Günter

    2015-07-01

    The objective of the Part II analysis was to evaluate animal and in vitro toxicology studies of CoCr particles with respect to their physicochemistry and dose relevance to metal-on-metal (MoM) implant patients as derived from Part I. In the various toxicology studies, physicochemical characteristics were infrequently considered and administered doses were orders of magnitude higher than what occurs in patients. Co was consistently shown to rapidly release from CoCr particles for distribution and elimination from the body. CoCr micron sized particles appear more biopersistent in vivo resulting in inflammatory responses that are not seen with similar mass concentrations of nanoparticles. We conclude, that in an attempt to obtain data for a complete risk assessment, future studies need to focus on physicochemical characteristics of nano and micron sized particles and on doses and dose metrics relevant to those generated in patients or in properly conducted hip simulator studies.

  2. Validation of primary metal-on-metal hip arthroplasties on the National Joint Registry for England, Wales and Northern Ireland using data from the London Implant Retrieval Centre: a study using the NJR dataset.

    PubMed

    Sabah, S A; Henckel, J; Cook, E; Whittaker, R; Hothi, H; Pappas, Y; Blunn, G; Skinner, J A; Hart, A J

    2015-01-01

    Arthroplasty registries are important for the surveillance of joint replacements and the evaluation of outcome. Independent validation of registry data ensures high quality. The ability for orthopaedic implant retrieval centres to validate registry data is not known. We analysed data from the National Joint Registry for England, Wales and Northern Ireland (NJR) for primary metal-on-metal hip arthroplasties performed between 2003 and 2013. Records were linked to the London Implant Retrieval Centre (RC) for validation. A total of 67,045 procedures on the NJR and 782 revised pairs of components from the RC were included. We were able to link 476 procedures (60.9%) recorded with the RC to the NJR successfully. However, 306 procedures (39.1%) could not be linked. The outcome recorded by the NJR (as either revised, unrevised or death) for a primary procedure was incorrect in 79 linked cases (16.6%). The rate of registry-retrieval linkage and correct assignment of outcome code improved over time. The rates of error for component reference numbers on the NJR were as follows: femoral head category number 14/229 (5.0%); femoral head batch number 13/232 (5.3%); acetabular component category number 2/293 (0.7%) and acetabular component batch number 24/347 (6.5%). Registry-retrieval linkage provided a novel means for the validation of data, particularly for component fields. This study suggests that NJR reports may underestimate rates of revision for many types of metal-on-metal hip replacement. This is topical given the increasing scope for NJR data. We recommend a system for continuous independent evaluation of the quality and validity of NJR data.

  3. Return to sporting activity after Birmingham hip resurfacing arthroplasty: Mid term results

    PubMed Central

    Sandiford, Nemandra; Muirhead-Allwood, SK; Skinner, JA

    2015-01-01

    Background: Hip resurfacing arthroplasty (HRA) is primarily indicated for young, active patients with disabling coxarthrosis who wish to remain active and return to sports after surgery. Relatively few prospective studies have assessed return to sporting activity and impact of gender and age on this. Materials and Methods: Seventy-nine consecutive patients treated with HRA were included. Patients were reviewed clinically and radiologically. Function was assessed using the modified University of California Los Angeles (UCLA) activity score. The Oxford, Harris and WOMAC hip scores were calculated. Results: Average age at the time of surgery was 54.9 years (range 34.5–73.6 years). Average preoperative and postoperative UCLA scores were 4 and 7.6 respectively. Patients were involved in 2 (0–4) sporting activities preoperatively and 2 (0–5) postoperatively. Preoperative and postoperative Oxford Hip Scores, Harris Hip Score and WOMAC scores were 40, 46 and 51 and 16, 94 and 3 respectively (P < 0.0001). Patients returned to sports at an average of 3 months postoperatively. Conclusion: Patients were able to return to sports by 3 months and perform the same number of activities at preoperative intensity. Activity levels are maintained up to the medium term with few complications. PMID:26806965

  4. Retrospective cohort study of the performance of the Pinnacle metal on metal (MoM) total hip replacement: a single-centre investigation in combination with the findings of a national retrieval centre

    PubMed Central

    Langton, David John; Sidaginamale, Raghavendra Prasad; Avery, Peter; Waller, Sue; Tank, Ghanshyabhai; Lord, James; Joyce, Thomas; Cooke, Nick; Logishetty, Raj; Nargol, Antoni Viraf Francis

    2016-01-01

    Objectives To determine risk factors for revision in patients implanted with a commonly used metal on metal (MoM) hip replacement. Design Retrospective cohort study in combination with a prospective national retrieval study (Northern Retrieval Registry (NRR)). Setting Combined orthopaedic unit in combination with the NRR. Participants All patients implanted with a DePuy Pinnacle MoM hip prostheses by the 2 senior authors were invited to attend for a review which included clinical examination, blood metal ion measurements, radiographs and targeted imaging. Explanted components underwent wear analysis using validated methodology and these results were compared with those obtained from the NRR. Results 489 MoM Pinnacle hips were implanted into 434 patients (243 females and 191 males). Of these, 352 patients attended the MoM recall clinics. 64 patients had died during the study period. For the purposes of survival analysis, non-attendees were assumed to have well-functioning prostheses. The mean follow-up of the cohort as a whole was 89 months. 71 hips were revised. Prosthetic survival for the whole cohort was 83.6% (79.9–87.3) at 9 years. The majority of explanted devices exhibited signs of taper junction failure. Risk factors for revision were bilateral MoM prostheses, smaller Pinnacle liners, and implantation in 2006 and later years. A significant number of devices were found to be manufactured out of their specifications. This was confirmed with analysis of the wider data set from the NRR. Conclusions This device was found to have an unacceptably high revision rate. Bilateral prostheses, those implanted into female patients and devices implanted in later years were found to be at greater risk. A significant number of explanted components were found to be manufactured with bearing diameters outside of the manufacturer's stated tolerances. Our findings highlight the clinical importance of hitherto unrecognised variations in device production. PMID:27130159

  5. Center of Mass Compensation during Gait in Hip Arthroplasty Patients: Comparison between Large Diameter Head Total Hip Arthroplasty and Hip Resurfacing

    PubMed Central

    Bouffard, Vicky; Nantel, Julie; Therrien, Marc; Vendittoli, Pascal-André; Lavigne, Martin; Prince, François

    2011-01-01

    Objective. To compare center of mass (COM) compensation in the frontal and sagittal plane during gait in patients with large diameter head total hip arthroplasty (LDH-THA) and hip resurfacing (HR). Design. Observational study. Setting. Outpatient biomechanical laboratory. Participants. Two groups of 12 patients with LDH-THA and HR recruited from a larger randomized study and 11 healthy controls. Interventions. Not applicable. Main Outcome Measures. To compare the distance between the hip prosthetic joint center (HPJC) and the COM. The ratio (RHPJC-COM) and the variability (CVHPJC-COM) were compared between groups. Hip flexor, abductor, and adductor muscle strength was also correlated between groups while radiographic measurements were correlated with the outcome measures. Results. In the frontal plane, HR shows less variability than healthy controls at push-off and toe-off and RHPJC-COM is correlated with the muscle strength ratios (FRABD) at heel contact, maximal weight acceptance, and mid stance. In the sagittal plane, LDH-THA has a higher RHPJC-COM than healthy controls at push-off, and CVHPJC-COM is significantly correlated with FRFLEX. Conclusions. One year after surgery, both groups of patients, LDH-THA and HR, demonstrate minor compensations at some specific instant of the gait cycle, in both frontal and sagittal planes. However, their locomotion pattern is similar to the healthy controls. PMID:22110976

  6. Pseudotumour incidence, cobalt levels and clinical outcome after large head metal-on-metal and conventional metal-on-polyethylene total hip arthroplasty: mid-term results of a randomised controlled trial.

    PubMed

    van der Veen, H C; Reininga, I H F; Zijlstra, W P; Boomsma, M F; Bulstra, S K; van Raay, J J A M

    2015-11-01

    We compared the incidence of pseudotumours after large head metal-on-metal (MoM) total hip arthroplasty (THA) with that after conventional metal-on-polyethylene (MoP) THA and assessed the predisposing factors to pseudotumour formation. From a previous randomised controlled trial which compared large head (38 mm to 60 mm) cementless MoM THA with conventional head (28 mm) cementless MoP THA, 93 patients (96 THAs: 41 MoM (21 males, 20 females, mean age of 64 years, standard deviation (sd) 4) and 55 MoP (25 males, 30 females, mean age of 65 years, sd 5) were recruited after a mean follow-up of 50 months (36 to 64). The incidence of pseudotumours, measured using a standardised CT protocol was 22 (53.7%) after MoM THA and 12 (21.8%) after MoP THA. Women with a MoM THA were more likely to develop a pseudotumour than those with a MoP THA (15 vs 7, odds ratio (OR) = 13.4, p < 0.001). There was a similar incidence of pseudotumours in men with MoM THAs and those with MoP THAs (7 vs 5, OR = 2.1, p = 0.30). Elevated cobalt levels (≥ 5 microgram/L) were only associated with pseudotumours in women with a MoM THA. There was no difference in mean Oxford and Harris hip scores between patients with a pseudotumour and those without. Contrary to popular belief, pseudotumours occur frequently around MoP THAs. Women with a MoM THA and an elevated cobalt level are at greatest risk. In this study, pseudotumours had no effect on the functional outcome after either large head MoM or conventional MoP THA.

  7. Revision of failed hip resurfacing to total hip arthroplasty rapidly relieves pain and improves function in the early post operative period

    PubMed Central

    2010-01-01

    We reviewed the results of 25 consecutive patients who underwent revision of a hip resurfacing prosthesis to a total hip replacement. Revisions were performed for recurrent pain and effusion, infection and proximal femoral fractures. Both components were revised in 20 cases. There were 12 male and 13 female patients with average time to revision of 34.4 and 26.4 months respectively. The mean follow up period was 12.7 months (3 to 31). All patients reported relief of pain and excellent satisfaction scores. Two patients experienced stiffness up to three months post operatively. Pre operative Oxford, Harris and WOMAC hip scores were 39.1, 36.4 and 52.2 respectively. Mean post operative scores at last follow up were 17.4, 89.8 and 6.1 respectively (p < 0.001 for each score). These results show that conversion of hip resurfacing to total hip arthroplasty has high satisfaction rates. These results compare favourably with those for revision total hip arthroplasty. PMID:21114835

  8. Lessons from retrievals: Retrievals help understand the reason for revision of coated hip arthroplasties.

    PubMed

    de Villiers, Danielle; Hothi, Harry; Khatkar, Harman; Meswania, Jayantilal; Blunn, Gordon; Skinner, John; Hart, Alister

    2015-11-01

    Coatings have been applied to all surfaces of hip implants with the majority performing well in the laboratory, but there are few reports of their performance in humans. The rationale for coating the metal-on-metal bearing surfaces includes a reduction in metal ion release and risk of adverse reaction to metal debris; yet there are no reports of retrieved coated metal-on-metal hip implants despite the concern that they may delaminate. The aim of this study was to better understand the performance of coated hip implants in humans through findings of three coated metal-on-metal hip resurfacings, retrieved after failure for unexplained pain. Analysis of these implants included quantification of the amount and mechanism of coating loss which was correlated with clinical, imaging and blood data. In all cases, there were large areas of complete coating loss in which the metal substrate was exposed and found to be rougher than the coated areas. The coating loss gave rise to third body abrasive wear of the coating and the exposed metal, the latter of which led to high blood levels of cobalt and chromium. Coating of the bearing surfaces of metal-on-metal hip resurfacings, therefore, do not prevent metal ion release when implanted into humans. This is an example of a need for increased retrieval analysis of newly introduced implants and expansion of laboratory testing regulations to better reflect the clinical environment.

  9. Hip Replacement: MedlinePlus Health Topic

    MedlinePlus

    ... and Drug Administration) Information for Patients Who Have Metal-on-Metal Hip Implants (Food and Drug Administration) Images Hip ... Article: Investigation of Taper Failure in a Contemporary Metal-on-Metal Hip Arthroplasty... Article: Effects of the ...

  10. Wear mechanisms in metal-on-metal bearings: the importance of tribochemical reaction layers.

    PubMed

    Wimmer, Markus A; Fischer, Alfons; Büscher, Robin; Pourzal, Robin; Sprecher, Christoph; Hauert, Roland; Jacobs, Joshua J

    2010-04-01

    Metal-on-metal (MoM) bearings are at the forefront in hip resurfacing arthroplasty. Because of their good wear characteristics and design flexibility, MoM bearings are gaining wider acceptance with market share reaching nearly 10% worldwide. However, concerns remain regarding potential detrimental effects of metal particulates and ion release. Growing evidence is emerging that the local cell response is related to the amount of debris generated by these bearing couples. Thus, an urgent clinical need exists to delineate the mechanisms of debris generation to further reduce wear and its adverse effects. In this study, we investigated the microstructural and chemical composition of the tribochemical reaction layers forming at the contacting surfaces of metallic bearings during sliding motion. Using X-ray photoelectron spectroscopy and transmission electron microscopy with coupled energy dispersive X-ray and electron energy loss spectroscopy, we found that the tribolayers are nanocrystalline in structure, and that they incorporate organic material stemming from the synovial fluid. This process, which has been termed "mechanical mixing," changes the bearing surface of the uppermost 50 to 200 nm from pure metallic to an organic composite material. It hinders direct metal contact (thus preventing adhesion) and limits wear. This novel finding of a mechanically mixed zone of nanocrystalline metal and organic constituents provides the basis for understanding particle release and may help in identifying new strategies to reduce MoM wear.

  11. Assessment of Patients with a DePuy ASR Metal-on-Metal Hip Replacement: Results of Applying the Guidelines of the Spanish Society of Hip Surgery in a Tertiary Referral Hospital.

    PubMed

    Fernández-Valencia, Jenaro; Gallart, Xavier; Bori, Guillem; Ramiro, Sebastián Garcia; Combalía, Andrés; Riba, Josep

    2014-01-01

    The prognosis associated with the DePuy ASR hip cup is poor and varies according to the series. This implant was withdrawn from use in 2010 and all patients needed to be assessed. We present the results of the assessment of our patients treated with this device, according to the Spanish Society of Hip Surgery (SECCA) algorithm published in 2011. This retrospective study evaluates 83 consecutive ASR cups, followed up at a mean of 2.9 years. Serum levels of chromium and cobalt, as well as the acetabular abduction angle, were determined in order to assess their possible correlation with failure, defined as the need for revision surgery. The mean Harris Hip Score was 83.2 (range 42-97). Eight arthroplasties (13.3%) required revision due to persistent pain and/or elevated serum levels of chromium/cobalt. All the cups had a correct abduction angle, and there was no correlation between elevated serum levels of metal ions and implant failure. Since two previous ASR implants were exchanged previously to the recall, the revision rate for ASR cups in our centre is 18.2% at 2.9 years.

  12. Current status of hemi-resurfacing arthroplasty for osteonecrosis of the hip: a 27-year experience.

    PubMed

    Amstutz, Harlan C; Le Duff, Michel J

    2009-04-01

    The purpose of the study discussed in this article is to review the authors' long-term experience with this procedure, compare their clinical results to those of other centers, particularly regarding the difficulty of predicting pain relief, and determine the role of hemi-resurfacing in the future.

  13. Detection of incorrect manufacturer labelling of hip components.

    PubMed

    Durand-Hill, Matthieu; Henckel, Johann; Burwell, Matthew; Skinner, John; Hart, Alister

    2017-01-01

    We describe the case of a 53-year-old man who underwent a left metal-on-metal hip resurfacing in 2015. Component size mismatch (CSM) was suspected because of the patient's immediate post-operative mechanical symptoms and high metal ion levels. Surgical notes indicated the appropriate combinations of implants were used. However, we detected a mismatch using computed tomography. Revision was performed and subsequent measurements of explanted components confirmed the mismatch. To our knowledge, this case is the first report of a CT method being used in a patient to pre-operatively identify CSM.

  14. Hip Implant Systems

    MedlinePlus

    ... Devices Products and Medical Procedures Implants and Prosthetics Metal-on-Metal Hip Implants Hip Implants Share Tweet Linkedin Pin ... devices available with different bearing surfaces. These are: Metal-on-Polyethylene: The ball is made of metal ...

  15. Toxicity of cobalt-chromium nanoparticles released from a resurfacing hip implant and cobalt ions on primary human lymphocytes in vitro.

    PubMed

    Posada, Olga M; Tate, R J; Grant, M H

    2015-06-01

    Adverse tissue responses to prostheses wear particles and released ions are important contributors to hip implant failure. In implant-related adverse reactions T-lymphocytes play a prominent role in sustaining the chronic inflammatory response. To further understand the involvement of lymphocytes in metal-on-metal (MoM) implant failure, primary human lymphocytes were isolated and treated with cobalt-chromium (Co-Cr) wear debris and Co ions, individually, and in combination, for 24, 48 and 120 h. There was a significant increase in cell number where debris was present, as measured by the Neutral Red assay. Interleukin-6 (IL-6), interferon-γ (IFN-γ) and tumour necrosis factor-α (TNF-α) secretion levels significantly decreased in the presence of metal particles, as measured by ELISA. Interleukin-2 (IL-2) secretion levels were significantly decreased by both debris and Co ions. Flow cytometry analysis showed that the metal nanoparticles induced a significant increase in apoptosis after 48-h exposure. This investigation showed that prolonged exposure (120 h) to metal debris induces lymphocyte proliferation, suggesting that activation of resting lymphocytes may have occurred. Although cytokine production was affected mainly by metal debris, cobalt toxicity may also modulate IL-2 secretion, and even Co ion concentrations below the MHRA guideline levels (7 ppb) may contribute to the impairment of immune regulation in vivo in patients with MoM implants.

  16. Accelerating failure rate of the ASR total hip replacement.

    PubMed

    Langton, D J; Jameson, S S; Joyce, T J; Gandhi, J N; Sidaginamale, R; Mereddy, P; Lord, J; Nargol, A V F

    2011-08-01

    There is widespread concern regarding the incidence of adverse soft-tissue reactions after metal-on-metal (MoM) hip replacement. Recent National Joint Registry data have shown clear differences in the rates of failure of different designs of hip resurfacing. Our aim was to update the failure rates related to metal debris for the Articular Surface Replacement (ASR). A total of 505 of these were implanted. Kaplan-Meier analysis showed a failure rate of 25% at six years for the ASR resurfacing and of 48.8% for the ASR total hip replacement (THR). Of 257 patients with a minimum follow-up of two years, 67 (26.1%) had a serum cobalt concentration which was greater than 7 μg/l. Co-ordinate measuring machine analysis of revised components showed that all patients suffering adverse tissue reactions in the resurfacing group had abnormal wear of the bearing surfaces. Six THR patients had relatively low rates of articular wear, but were found to have considerable damage at the trunion-taper interface. Our results suggest that wear at the modular junction is an important factor in the development of adverse tissue reactions after implantation of a large-diameter MoM THR.

  17. Comparative study of material loss at the taper interface in retrieved metal-on-polyethylene and metal-on-metal femoral components from a single manufacturer.

    PubMed

    Bills, Paul; Racasan, Radu; Bhattacharya, Saugatta; Blunt, Liam; Isaac, Graham

    2017-04-01

    There have been a number of reports on the occurrence of taper corrosion and/or fretting and some have speculated on a link to the occurrence of adverse local tissue reaction specifically in relation to total hip replacement which have a metal-on-metal bearing. As such a study was carried out to compare the magnitude of material loss at the taper in a series of retrieved femoral heads used in metal-on-polyethylene bearings with that in a series of retrieved heads used in metal-on-metal bearings. A total of 36 metal-on-polyethylene and 21 metal-on-metal femoral components were included in the study all of which were received from a customer complaint database. Furthermore, a total of nine as-manufactured femoral components were included to provide a baseline for characterisation. All taper surfaces were assessed using an established corrosion scoring method and measurements were taken of the female taper surface using a contact profilometry. In the case of metal-on-metal components, the bearing wear was also assessed using coordinate metrology to determine whether or not there was a relationship between bearing and taper material loss in these cases. The study found that in this cohort the median value of metal-on-polyethylene taper loss was 1.25 mm(3) with the consequent median value for metal-on-metal taper loss being 1.75 mm(3). This study also suggests that manufacturing form can result in an apparent loss of material from the taper surface determined to have a median value of 0.59 mm(3). Therefore, it is clear that form variability is a significant confounding factor in the measurement of material loss from the tapers of femoral heads retrieved following revision surgery.

  18. Laser resurfacing pearls.

    PubMed

    Shah, Sonia; Alam, Murad

    2012-08-01

    Ablative skin resurfacing using the carbon dioxide laser was long considered the gold standard for treatment of photoaging, acne scars, and rhytids. However, conventional full-face carbon dioxide resurfacing is associated with significant risk of side effects and a prolonged postoperative recovery period. Fractional resurfacing has recently revolutionized laser surgery by offering close to comparable results with minimal side effects and a more rapid recovery. Although fractional devices have grown in popularity, and have essentially replaced traditional resurfacing, fractional resurfacing can still be a challenging modality to control precisely due to hardware variations across comparable devices, the range of settings that can be used, and patient-specific considerations. Certain precautions and rules of thumb can reduce the risk associated with fractional resurfacing, and increase the likelihood of a good outcome.

  19. New insights into hard phases of CoCrMo metal-on-metal hip replacements.

    PubMed

    Liao, Y; Pourzal, R; Stemmer, P; Wimmer, M A; Jacobs, J J; Fischer, A; Marks, L D

    2012-08-01

    The microstructural and mechanical properties of the hard phases in CoCrMo prosthetic alloys in both cast and wrought conditions were examined using transmission electron microscopy and nanoindentation. Besides the known carbides of M(23)C(6)-type (M=Cr, Mo, Co) and M(6)C-type which are formed by either eutectic solidification or precipitation, a new mixed-phase hard constituent has been found in the cast alloys, which is composed of ∼100 nm fine grains. The nanosized grains were identified to be mostly of M(23)C(6) type using nano-beam precession electron diffraction, and the chemical composition varied from grain to grain being either Cr- or Co-rich. In contrast, the carbides within the wrought alloy having the same M(23)C(6) structure were homogeneous, which can be attributed to the repeated heating and deformation steps. Nanoindentation measurements showed that the hardness of the hard phase mixture in the cast specimen was ∼15.7 GPa, while the M(23)C(6) carbides in the wrought alloy were twice as hard (∼30.7 GPa). The origin of the nanostructured hard phase mixture was found to be related to slow cooling during casting. Mixed hard phases were produced at a cooling rate of 0.2 °C/s, whereas single phase carbides were formed at a cooling rate of 50 °C/s. This is consistent with sluggish kinetics and rationalizes different and partly conflicting microstructural results in the literature, and could be a source of variations in the performance of prosthetic devices in-vivo.

  20. Ablative skin resurfacing.

    PubMed

    Agrawal, Nidhi; Smith, Greg; Heffelfinger, Ryan

    2014-02-01

    Ablative laser resurfacing has evolved as a safe and effective treatment for skin rejuvenation. Although traditional lasers were associated with significant thermal damage and lengthy recovery, advances in laser technology have improved safety profiles and reduced social downtime. CO2 lasers remain the gold standard of treatment, and fractional ablative devices capable of achieving remarkable clinical improvement with fewer side effects and shorter recovery times have made it a more practical option for patients. Although ablative resurfacing has become safer, careful patient selection and choice of suitable laser parameters are essential to minimize complications and optimize outcomes. This article describes the current modalities used in ablative laser skin resurfacing and examines their efficacy, indications, and possible side effects.

  1. Ablative skin resurfacing.

    PubMed

    Chwalek, Jennifer; Goldberg, David J

    2011-01-01

    Ablative skin resurfacing has remained the gold standard for treating photodamage and acne scars since the development of the first CO(2) lasers. CO(2) and Er:YAG lasers emit infrared light, which targets water resulting in tissue contraction and collagen formation. The first ablative laser systems created significant thermal damage resulting in unacceptably high rates of scarring and prolonged healing. Newer devices, such as high-energy pulsed lasers and fractional ablative lasers, are capable of achieving significant improvements with fewer side effects and shorter recovery times. While ablative resurfacing has become safer, careful patient selection is still important to avoid post-treatment scarring, dyspigmentation, and infections. Clinicians utilizing ablative devices need to be aware of possible side effects in order to maximize results and patient satisfaction. This chapter reviews the background of ablative lasers including the types of ablative lasers, mechanism of action, indications for ablative resurfacing, and possible side effects.

  2. CO2 laser resurfacing.

    PubMed

    Fitzpatrick, R E

    2001-07-01

    The CO2 Laser offers a variety of unique features in resurfacing facial photodamage and acne scarring. These include hemostasis, efficient removal of the epidermis in a single pass, thermally induced tissue tightening, and safe, predictable tissue interaction. Knowledge of these mechanisms will result in the capability of using the CO2 laser effectively and safely whether the goal is superficial or deep treatment.

  3. Worse health-related quality of life and hip function in female patients with elevated chromium levels.

    PubMed

    Hussey, Daniel K; Madanat, Rami; Donahue, Gabrielle S; Rolfson, Ola; Muratoglu, Orhun K; Malchau, Henrik

    2016-10-01

    Background and purpose - Blood metal ion levels can be an indicator for detecting implant failure in metal-on-metal (MoM) hip arthroplasties. Little is known about the effect of bilateral MoM implants on metal ion levels and patient-reported outcomes. We compared unilateral patients and bilateral patients with either an ASR hip resurfacing (HR) or an ASR XL total hip replacement (THR) and investigated whether cobalt or chromium was associated with a broad spectrum of patient outcomes. Patients and methods - From a registry of 1,328 patients enrolled in a multicenter prospective follow-up of the ASR Hip System, which was recalled in 2010, we analyzed data from 659 patients (311 HR, 348 THR) who met our inclusion criteria. Cobalt and chromium blood metal ion levels were measured and a 21-item patient-reported outcome measures (PROMs) questionnaire was used mean 6 years after index surgery. Results - Using a minimal threshold of ≥7 ppb, elevated chromium ion levels were found to be associated with worse health-related quality of life (HRQoL) (p < 0.05) and hip function (p < 0.05) in women. These associations were not observed in men. Patients with a unilateral ASR HR had lower levels of cobalt ions than bilateral ASR HR patients (p < 0.001) but similar levels of chromium ions (p = 0.09). Unilateral ASR XL THR patients had lower chromium and cobalt ion levels (p < 0.005) than bilateral ASR XL THR patients. Interpretation - Chromium ion levels of ≥7 ppb were associated with reduced functional outcomes in female MoM patients.

  4. Histologic effects of resurfacing lasers.

    PubMed

    Freedman, Joshua R; Greene, Ryan M; Green, Jeremy B

    2014-02-01

    By utilizing resurfacing lasers, physicians can significantly improve the appearance of sun-damaged skin, scars, and more. The carbon dioxide and erbium:yttrium-aluminum-garnet lasers were the first ablative resurfacing lasers to offer impressive results although these earlier treatments were associated with significant downtime. Later, nonablative resurfacing lasers such as the neodymium:yttrium-aluminum-garnet laser proved effective, after a series of treatments with less downtime, but with more modest results. The theory of fractional photothermolysis has revolutionized resurfacing laser technology by increasing the safety profile of the devices while delivering clinical efficacy. A review of the histologic and molecular consequences of the resurfacing laser-tissue interaction allows for a better understanding of the devices and their clinical effects.

  5. Fractional laser skin resurfacing.

    PubMed

    Alexiades-Armenakas, Macrene R; Dover, Jeffrey S; Arndt, Kenneth A

    2012-11-01

    Laser skin resurfacing (LSR) has evolved over the past 2 decades from traditional ablative to fractional nonablative and fractional ablative resurfacing. Traditional ablative LSR was highly effective in reducing rhytides, photoaging, and acne scarring but was associated with significant side effects and complications. In contrast, nonablative LSR was very safe but failed to deliver consistent clinical improvement. Fractional LSR has achieved the middle ground; it combined the efficacy of traditional LSR with the safety of nonablative modalities. The first fractional laser was a nonablative erbium-doped yttrium aluminum garnet (Er:YAG) laser that produced microscopic columns of thermal injury in the epidermis and upper dermis. Heralding an entirely new concept of laser energy delivery, it delivered the laser beam in microarrays. It resulted in microscopic columns of treated tissue and intervening areas of untreated skin, which yielded rapid reepithelialization. Fractional delivery was quickly applied to ablative wavelengths such as carbon dioxide, Er:YAG, and yttrium scandium gallium garnet (2,790 nm), providing more significant clinical outcomes. Adjustable laser parameters, including power, pitch, dwell time, and spot density, allowed for precise determination of percent surface area, affected penetration depth, and clinical recovery time and efficacy. Fractional LSR has been a significant advance to the laser field, striking the balance between safety and efficacy.

  6. Current role of resurfacing lasers.

    PubMed

    Hantash, B M; Gladstone, H B

    2009-06-01

    Resurfacing lasers have been the treatment of choice for diminishing rhytids and tightening skin. The carbon dioxide and erbium lasers have been the gold and silver standards. Despite their effectiveness, these resurfacing lasers have a very high risk profile including scarring, hyperpigmentation and hypopigmentation. Because of these side effects, various practitioners have tried alternative settings for these lasers as well as alternative wavelengths, particularly in the infrared spectrum. These devices have had less downtime, but their effectiveness has been limited to fine wrinkles. As with selective photothemolysis, a major advance in the field has been fractionated resurfacing which incorporates grids of microthermal zones that spares islands of skin. This concept permits less tissue damage and quicker tissue regeneration. Initially, fractionated resurfacing was limited to the nonablative mid-infrared spectrum. These resurfacing lasers is appropriate for those patients with acne scars, uneven skin tone, mild to moderate photodamage, and is somewhat effective for melasma. Importantly, because there is less overall tissue damage and stimulation of melanocytes, these lasers can be used in darker skin types. Downtime is 2-4 days of erythema and scaling. Yet, these nonablative fractionated devices required 5-6 treatments to achieve a moderate effect. Logically, the fractionated resurfacing has now been applied to the CO2 and the Erbium:Yag lasers. These devices can treat deeper wrinkles and tighten skin. Downtime appears to be 5-7 days. The long term effectiveness and the question of whether these fractionated devices will approach the efficacy of the standard resurfacing lasers is still in question. Ultimately either integrated devices which may use fractionated resurfacing, radiofrequency and a sensitizer, or combining different lasers in a single treatment may prove to be the most effective in reducing rhtyides, smoothing the skin topography and tightening the

  7. Formation of molten metal films during metal-on-metal slip under extreme interfacial conditions

    NASA Astrophysics Data System (ADS)

    Liou, Nai-Shang; Okada, Makoto; Prakash, Vikas

    2004-09-01

    The present paper describes results of plate-impact pressure-shear friction experiments conducted to study time-resolved growth of molten metal films during dry metal-on-metal slip under extreme interfacial conditions. By employing tribo-pairs comprising hard tool-steel against relatively low melt-point metals such as 7075-T6 aluminum alloys, interfacial friction stress ranging from 100 to 400 MPa and slip speeds of approximately 100 m/ s have been generated. These relatively high levels of friction stress combined with high slip-speeds generate conditions conducive for interfacial temperatures to approach the melting point of the lower melt point metal (Al alloy) comprising the tribo-pair. A Lagrangian finite element code is developed to understand the evolution of the thermo-mechanical fields and their relationship to the observed slip response. The code accounts for dynamic effects, heat conduction, contact with friction, and full thermo-mechanical coupling. At temperatures below the melting point the material is described as an isotropic thermally softening elastic-viscoplastic solid. For material elements with temperatures in excess of the melt point a purely Newtonian fluid constitutive model is employed. The results of the hybrid experimental-computational study provides new insights into the thermoelastic-plastic interactions during high speed metal-on-metal slip under extreme interfacial conditions. During the early part of frictional slip the coefficient of kinetic friction is observed to decrease with increasing slip velocity. During the later part transition in interfacial slip occurs from dry metal-on-metal sliding to the formation of molten Al films at the tribo-pair interface. Under these conditions the interfacial resistance approaches the shear strength of the molten aluminum alloy under normal pressures of approximately 1- 3 GPa and shear strain rates of ˜10 7 s-1. The results of the study indicate that under these extreme conditions molten

  8. Resurfacing processes on Vesta

    NASA Astrophysics Data System (ADS)

    Krohn, K.; Jaumann, R.; Otto, K.; Elbeshausen, D.; Stephan, K.; Kneissl, T.; Schmedemann, N.; Roatsch, T.; Raymond, C.; Russell, C.

    2014-07-01

    Planetary surfaces are steadily modified by endogenic processes. The most important resurfacing processes on dry airless bodies are: mass-wasting processes, volcanic activity, and tectonics due to impact cratering. Due to the absence of volcanic activity on Vesta [1], mass wasting and impact cratering are the most likely resurfacing processes on Vesta. The high elevation differences on Vesta [2] and the steady bombardment of Vesta's surface by impacts cause seismic shaking which promote material to move downwards. We analyzed different types of mass-wasting features in the South Polar Region, such as slumping blocks at the steep scarp Matronalia Rupes, spur-and-gully morphologies, and landslides in craters [3]. Collapse processes, instability of slopes, and seismic-triggered events cause the landslides, rotational slumping blocks on scarps, as well as spur-and-gully morphologies on crater walls and scarps. Spur-and-gully morphology is known to form on Mars and the Earth normally supported by liquid flow but, on Vesta, these features formed under dry conditions. At Matronalia Rupes, rotational rock slumping blocks are clearly exposed as material slumped down the scarp wall in a stair-stepped pattern, which is interrupted by minor scarps and covers the underlying terrain. This rotational rock slumping is affected by slope instability and gravitationally triggered events, such as seismic shaking mostly produced by impacts elsewhere on Vesta [3]. The sloping surface of Vesta cause not only the formation of mass wasting features, but also the formation of craters on slopes. These craters are in turn influenced by mass wasting and show an asymmetric crater shape with a sharp uphill rim and a smooth downhill rim. The craters show a sharp crater rim uphill and a smooth one downhill as well as ejecta on the downhill rim and only thin ejecta over the uphill rim. Three-dimensional numerical simulations have been performed to study the formation process of the unusual craters

  9. Review of cobalt toxicokinetics following oral dosing: Implications for health risk assessments and metal-on-metal hip implant patients.

    PubMed

    Tvermoes, Brooke E; Paustenbach, Dennis J; Kerger, Brent D; Finley, Brent L; Unice, Kenneth M

    2015-05-01

    Cobalt (Co) can stimulate erythropoietin production in individuals at doses exceeding 25 mg CoCl2/day. Co has also been shown to exert effects on the thyroid gland, heart and nervous system at sufficient doses. The biological activity of Co is dictated by the concentration of free (unbound) ionic Co(2+). Blood concentrations, as well as, urinary excretion rates of Co are reliable biomarkers for systemic Co exposure. A recent series of human volunteer Co-supplement studies simultaneously measured Co blood and urine concentrations, as well as, Co speciation in serum, and a number of biochemical and clinical parameters. It was found in these studies that peak Co whole blood concentration as high as 117 μg/L were not associated with changes in hematological parameters such as increased red blood cell (RBC) count, hemoglobin (Hgb) or hematocrit (Hct) levels, nor with changes in cardiac, neurological or, thyroid function. Using a Co biokinetic model, the estimated Co systemic tissue concentrations (e.g., liver, kidney, and heart) following 90-days of Co-dietary supplementation with ∼1 mg Co/day were found to be similar to estimated tissue concentrations in implant patients after 10 years of exposure at continuous steady state Co blood concentration of ∼10 μg/L. This study is the first to present modeled Co tissue concentrations at various doses following sub-chronic and chronic exposure. The modeled steady state tissue Co concentrations in combination with the data on adverse health effects in humans should help in the characterization of potential hazards associated with increased blood Co concentrations due to exposure to dietary supplements or cobalt-chromium (Co-Cr) containing implants.

  10. The Interchangeability of Plasma and Whole Blood Metal Ion Measurement in the Monitoring of Metal on Metal Hips

    PubMed Central

    Malek, Ibrahim A.; Rogers, Joanne; King, Amanda Christina; Clutton, Juliet; Winson, Daniel; John, Alun

    2015-01-01

    One hundred and twenty six paired samples of plasma and whole blood were measured with inductively coupled plasma mass spectrometry technique for metal ions analysis to determine a relationship between them. There was a significant difference between the mean plasma and whole blood concentrations of both cobalt (Co) and chromium (Cr) (p < 0.0001 for both Co and Cr). The mean ratio between plasma and whole blood Cr and Co was 1.56 (range: 0.39–3.85) and 1.54 (range: 0.64–18.26), respectively, but Bland and Altman analysis illustrated that this relationship was not universal throughout the range of concentrations. There was higher variability at high concentrations for both ions. We conclude that both these concentrations should not be used interchangeably and conversion factors are unreliable due to concentration dependent variability. PMID:26798516

  11. Is Increased Modularity Associated With Increased Fretting and Corrosion Damage in Metal-On-Metal Total Hip Arthroplasty Devices?

    PubMed Central

    Higgs, Genymphas B.; Hanzlik, Josa A.; MacDonald, Daniel W.; Gilbert, Jeremy L.; Rimnac, Clare M.; Kurtz, Steven M.

    2014-01-01

    This retrieval study documents taper damage at modular interfaces in retrieved MOM THA systems and investigates if increased modularity is associated with increased fretting and corrosion. One hundred thirty-four (134) heads and 60 stems (41 modular necks) of 8 different bearing designs (5 manufacturers) were analyzed. Damage at the shell–liner interface of 18 modular CoCr acetabular liners and the corresponding 11 acetabular shells was also evaluated. The results of this study support the hypothesis that fretting and corrosion damage occurs at a variety of modular component interfaces in contemporary MOM THAs. We also found that modularity of the femoral stem was associated with increased damage at the head. An analysis of component and patient variables revealed that dissimilar alloy pairing, larger head sizes, increased medio-lateral offsets and longer neck moment arms were all associated with increased taper damage at the modular interfaces. PMID:23910820

  12. Skin resurfacing procedures: new and emerging options

    PubMed Central

    Loesch, Mathew M; Somani, Ally-Khan; Kingsley, Melanie M; Travers, Jeffrey B; Spandau, Dan F

    2014-01-01

    The demand for skin resurfacing and rejuvenating procedures has progressively increased in the last decade and has sparked several advances within the skin resurfacing field that promote faster healing while minimizing downtime and side effects for patients. Several technological and procedural skin resurfacing developments are being integrated into clinical practices today allowing clinicians to treat a broader range of patients’ skin types and pathologies than in years past, with noteworthy outcomes. This article will discuss some emerging and developing resurfacing therapies and treatments that are present today and soon to be available. PMID:25210469

  13. Skin resurfacing procedures: new and emerging options.

    PubMed

    Loesch, Mathew M; Somani, Ally-Khan; Kingsley, Melanie M; Travers, Jeffrey B; Spandau, Dan F

    2014-01-01

    The demand for skin resurfacing and rejuvenating procedures has progressively increased in the last decade and has sparked several advances within the skin resurfacing field that promote faster healing while minimizing downtime and side effects for patients. Several technological and procedural skin resurfacing developments are being integrated into clinical practices today allowing clinicians to treat a broader range of patients' skin types and pathologies than in years past, with noteworthy outcomes. This article will discuss some emerging and developing resurfacing therapies and treatments that are present today and soon to be available.

  14. [CT and MRI of hip arthroplasty].

    PubMed

    Agten, C A; Sutter, R; Pfirrmann, C W A

    2014-07-01

    Metal-induced artifacts impair image quality of computed tomography (CT) and magnetic resonance imaging (MRI) in patients with hip prostheses. Due to new developments in metal artifact reduction both methods can now be used for evaluation of a painful hip prosthesis. Iterative reconstruction algorithms and dual-energy scans are among the newer CT techniques for artifact reduction, while slice-encoding for metal artifact correction (SEMAC) and multi-acquisition variable-resonance image combination (MAVRIC) have introduced substantial improvements for MRI. Loosening of the hip prosthesis, osteolysis from small wear particles and pseudotumors in metal-on-metal prostheses are specific pathologies in patients with total hip arthroplasty. Other causes of painful hip prostheses are infections, fractures, tendinopathies, tendon ruptures, muscle and nerve alterations and heterotopic ossifications.

  15. Clinical Performance of the ASR and ReCap Resurfacing Implants—7 Years Follow-Up.

    PubMed

    Borgwardt, Arne; Borgwardt, Lotte; Borgwardt, Lise; Zerahn, Bo; Fabricius, Sandra D; Ribel-Madsen, Søren

    2015-06-01

    We perform a non-randomized, consecutive pilot study on the ASR and ReCap resurfacing hip implants and have completed 7 years follow-up. Forty-six non-osteoporotic patients with hip osteoarthritis and anatomical conditions suitable for resurfacing were divided into 2 equal groups and operated sequentially, starting with the ASR implants. Sixteen patients operated with ASR and 19 patients with ReCap have been followed-up. There were no significant differences between the two groups preoperatively as to physical function, pain, or femoral BMD. The serum concentrations of cobalt and chromium were higher in the ASR group from 1/2 to 7 years postoperatively. Five of 16 ASR implants have been revised, and none of the ReCap implants. BMD below the femoral component increased in both groups.

  16. Hip pain

    MedlinePlus

    ... pain involves any pain in or around the hip joint. You may not feel pain from your hip ... 2012:chap 48. Read More Hip fracture surgery Hip joint replacement Patient Instructions Hip fracture - discharge Hip or ...

  17. Automatic assessment of volume asymmetries applied to hip abductor muscles in patients with hip arthroplasty

    NASA Astrophysics Data System (ADS)

    Klemt, Christian; Modat, Marc; Pichat, Jonas; Cardoso, M. J.; Henckel, Joahnn; Hart, Alister; Ourselin, Sebastien

    2015-03-01

    Metal-on-metal (MoM) hip arthroplasties have been utilised over the last 15 years to restore hip function for 1.5 million patients worldwide. Althoug widely used, this hip arthroplasty releases metal wear debris which lead to muscle atrophy. The degree of muscle wastage differs across patients ranging from mild to severe. The longterm outcomes for patients with MoM hip arthroplasty are reduced for increasing degrees of muscle atrophy, highlighting the need to automatically segment pathological muscles. The automated segmentation of pathological soft tissues is challenging as these lack distinct boundaries and morphologically differ across subjects. As a result, there is no method reported in the literature which has been successfully applied to automatically segment pathological muscles. We propose the first automated framework to delineate severely atrophied muscles by applying a novel automated segmentation propagation framework to patients with MoM hip arthroplasty. The proposed algorithm was used to automatically quantify muscle wastage in these patients.

  18. A tectonic resurfacing model for Venus

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.

    1993-01-01

    Two remarkable aspects of the population of impact craters on Venus are that craters at all sizes are indistinguishable from a random population and that the vast majority of craters have not been significantly modified by tectonic strain or by volcanic flows external to the crater rim, despite evidence from Magellan images that volcanic and tectonic features are widespread on Venus. One interpretation of these observations is that most of the surface dates from the end of a catastrophic global resurfacing event that ceased about 500 My ago, and that the small fraction of craters volcanically embayed or modified by deformation indicates that volcanic and tectonic activity subsequent to that time has been at much lower levels. An alternative model, in which resurfacing occurs episodically in patches a few hundred kilometers in extent and there is a wider spectrum of surface ages, also appears to be consistent with the characteristics of impact craters on Venus. A number of potential mechanisms for catastrophic resurfacing of Venus have been proposed, ranging from geologically sudden convective destabilization of the global lithosphere to strongly time-dependent heat flux and melt generation in the underlying mantle. In most of these geophysical models, resurfacing occurs implicitly or explicitly by volcanism. We explore the hypothesis that, at least in the geologically recent history of Venus, the primary resurfacing mechanism has been tectonic deformation rather than volcanism. We show how such a hypothesis provides at least as good an explanation of a wide range of observations as do volcanic resurfacing models. Finally, we explore the implications of tectonic resurfacing hypothesis for the controversy over the recent resurfacing history of the planet.

  19. Laser Resurfacing: Full Field and Fractional.

    PubMed

    Pozner, Jason N; DiBernardo, Barry E

    2016-07-01

    Laser resurfacing is a very popular procedure worldwide. Full field and fractional lasers are used in many aesthetic practices. There have been significant advances in laser resurfacing in the past few years, which make patient treatments more efficacious and with less downtime. Erbium and carbon dioxide and ablative, nonablative, and hybrid fractional lasers are all extremely effective and popular tools that have a place in plastic surgery and dermatology offices.

  20. Selective Patellar Resurfacing: A Literature Review.

    PubMed

    Antholz, Casey R; Cherian, Jeffrey J; Elmallah, Randa K; Jauregui, Julio J; Pierce, Todd P; Mont, Micael A

    2015-05-01

    Whether to resurface the patella during total knee arthroplasty (TKA) remains a controversial topic among orthopaedic surgeons, and we are still no closer to identifying which technique provides the best outcomes. Advocates for patellar resurfacing have adopted this technique in order to avoid the potential for post-operative anterior knee pain that may be associated with the need for future reoperations. However, reports have indicated that patellar resurfacing may be associated with increased complications such as patellar implant loosening, fracture, osteonecrosis, tendon injury, wear, and instability. More recently, studies have highlighted possible patient-specific and surgical factors, such as weight, body mass index, degree of chondromalacia, and patellar alignment, which may influence functional outcomes, and thus surgical decision making. However, currently there are minimal clear guidelines to help surgeons decide whether or not to resurface the patella. Our aim was to assess the current literature and present the evidence for and against patellar resurfacing, as well as to assess factors that may aid in deciding which procedure is more suitable for the specific patient. Ultimately, we believe there is a need for further research to identify the most appropriate candidates for patellar resurfacing.

  1. Histopathology of laser skin resurfacing

    NASA Astrophysics Data System (ADS)

    Thomsen, Sharon L.; Baldwin, Bonnie; Chi, Eric; Ellard, Jeff; Schwartz, Jon A.

    1997-05-01

    Pulsed carbon-dioxide laser skin resurfacing is a purportedly 'non-thermal' procedure enjoying wide application as a cosmetic treatment for skin wrinkles. Treatment success has been based on clinical assessments of skin smoothness. Skin lesions (1 cm2) created by one, two or three superimposed carbon-dioxide laser passes were placed on the backs of 28 'fuzzy' Harlan Sprague Dawley rats. The variable laser irradiation parameters included measured energies ranging from 112 to 387/pulse with pulse widths of 65 and 125 microseconds and a repetition rate of 8 Hz. The square, flat laser beam measured 3 mm2 at the focal point. The lesions were collected from 0 to 10 days after treatment for qualitative and quantitative histopathology. Thermal damage and treatment effect tended to increase in severity and, to a lesser extent, depth with increased delivery parameters. In acute lesions, the vacuolated and fragmented, desiccated and thermally coagulated epidermis was partially removed exposing the underlying thermally coagulated dermal collagen and cells. Epidermal and dermal necrosis and slough occurred between 24 to 72 hours after treatment. Epithelial regeneration originated from the adnexa and the lesion edges. Dermal fibrous scar formation began at 5 days below the regenerated epidermis and became more prominent at 7 and 10 days.

  2. Cementless Total Hip Arthroplasty Involving Trochanteric Osteotomy without Subtrochanteric Shortening for High Hip Dislocation

    PubMed Central

    Lee, Soong Joon; Kim, Hee Joong

    2017-01-01

    Background Total hip arthroplasty with subtrochanteric shortening osteotomy is widely performed for high hip dislocation. However, suboptimal leg length discrepancy correction and nonunion of the osteotomy site remain concerns. Although total hip arthroplasty using trochanteric osteotomy without subtrochanteric osteotomy was introduced, cemented implants have been more commonly used than contemporary cementless implants in this procedure. We evaluated the long-term results of cementless total hip arthroplasty with trochanteric osteotomy without subtrochanteric osteotomy for high hip dislocation. Methods From 1990 to 2002, 27 cementless total hip arthroplasties using trochanteric osteotomy without subtrochanteric osteotomy were performed in 26 patients with Crowe III or IV high hip dislocation and a mean age of 36.4 ± 12.9 years. Seven ceramic-on-ceramic, 8 ceramic-on-polyethylene, 10 metal-on-polyethylene, and 2 metal-on-metal bearings were inserted. Mean follow-up was 15.1 ± 3.7 years. We retrospectively reviewed medical records and radiographic data and evaluated the clinical and radiological results including the Harris hip score, implant survival, correction of leg length discrepancy, and occurrence of complications. Results The mean Harris hip score and leg length discrepancy improved significantly from 73.3 to 94.9 points and from 4.3 cm to 1.0 cm, respectively. With revision for loosening set as the end point, implant survival rates at 10 and 15 years postoperatively were 96.0% and 90.9% for stems and 74.1% and 52.3% for cups. In 8 of 10 hips with the metal-on-polyethylene bearing and 4 of 8 hips with the ceramic-on-polyethylene bearing, revision surgery was performed for aseptic loosening. However, no revision was performed in hips with the ceramic-on-ceramic bearing or the metal-on-metal bearing. Implant survival was significantly different by the type of bearing surface. Two permanent neurologic complications occurred in patients with a limb lengthening

  3. Fractional ablative laser skin resurfacing: a review.

    PubMed

    Tajirian, Ani L; Tarijian, Ani L; Goldberg, David J

    2011-12-01

    Ablative laser technology has been in use for many years now. The large side effect profile however has limited its use. Fractional ablative technology is a newer development which combines a lesser side effect profile along with similar efficacy. In this paper we review fractional ablative laser skin resurfacing.

  4. Erbium laser resurfacing for actinic cheilitis.

    PubMed

    Cohen, Joel L

    2013-11-01

    Actinic cheilitis is a precancerous condition characterized by grayish-whitish area(s) of discoloration on the mucosal lip, often blunting the demarcation between mucosa and cutaneous lip. Actinic cheilitis is considered to be an early part of the spectrum of squamous cell carcinoma. Squamous cell carcinoma specifically of the lip has a high rate of recurrence and metastasis through the oral cavity leading to a poor overall survival. Risk factors for the development of actinic cheilitis include chronic solar irradiation, increasing age, male gender, light skin complexion, immunosuppression, and possibly tobacco and alcohol consumption. Treatment options include topical pharmacotherapy (eg, fluorouracil, imiquimod) or procedural interventions (eg, cryotherapy, electrosurgery, surgical vermillionectomy, laser resurfacing), each with their known advantages and disadvantages. There is little consensus as to which treatment options offer the most clinical utility given the paucity of comparative clinical data. In my practice, laser resurfacing has become an important tool for the treatment of actinic cheilitis owing to its ease of use and overall safety, tolerability, and cosmetic acceptability. Herein the use of erbium laser resurfacing is described for three actinic cheilitis presentations for which I find it particularly useful: clinically prominent actinic cheilitis, biopsy-proven actinic cheilitis, and treatment of the entire lip following complete tumor excision of squamous cell carcinoma. All patients were treated with a 2940-nm erbium laser (Sciton Profile Contour Tunable Resurfacing Laser [TRL], Sciton, Inc., Palo Alto, CA).

  5. Revision of failed humeral head resurfacing arthroplasty

    PubMed Central

    Streubel, Philipp N.; Simone, Juan P.; Cofield, Robert H.; Sperling, John W.

    2016-01-01

    Purpose: The purpose of this study is to assess the outcomes of a consecutive series of patients who underwent revision surgery after humeral head resurfacing (HHR). Our joint registry was queried for all patients who underwent revision arthroplasty for failed HHR at our institution from 2005 to 2010. Eleven consecutive patients (average age 54 years; range 38-69 years) that underwent revision of 11 resurfacing arthroplasties were identified. The primary indication for resurfacing had been osteoarthritis in six, glenoid dysplasia in two, a chondral lesion in two, and postinstability arthropathy in one patient. The indication for revision was pain in 10 and infection in one patient. Seven patients had undergone an average of 1.9 surgeries prior to resurfacing (range 1-3). Materials and Methods: All patients were revised to stemmed arthroplasties, including one hemiarthroplasty, two reverse, and eight anatomic total shoulder arthroplasties at a mean 33 months after primary resurfacing (range 10-131 months). A deltopectoral approach was used in seven patients; four patients required an anteromedial approach due to severe scarring. Subscapularis attenuation was found in four cases, two of which required reverse total shoulder arthroplasty. Bone grafting was required in one glenoid and three humeri. Results: At a mean follow-up of 3.5 years (range 1.6-6.9 years), modified Neer score was rated as satisfactory in five patients and unsatisfactory in six. Abduction and external rotation improved from 73° to 88° (P = 0.32) and from 23° to 32° (P = 0.28) respectively. Reoperation was required in two patients, including one hematoma and one revision for instability. Conclusion: Outcomes of revision of HHR arthroplasty in this cohort did not improve upon those reported for revision of stemmed humeral implants. A comparative study would be required to allow for definitive conclusions to be made. PMID:26980986

  6. Hip Pain

    MedlinePlus

    ... clues about the underlying cause. Problems within the hip joint itself tend to result in pain on the ... tendons and other soft tissues that surround your hip joint. Hip pain can sometimes be caused by diseases ...

  7. Biotribology of artificial hip joints

    PubMed Central

    Di Puccio, Francesca; Mattei, Lorenza

    2015-01-01

    Hip arthroplasty can be considered one of the major successes of orthopedic surgery, with more than 350000 replacements performed every year in the United States with a constantly increasing rate. The main limitations to the lifespan of these devices are due to tribological aspects, in particular the wear of mating surfaces, which implies a loss of matter and modification of surface geometry. However, wear is a complex phenomenon, also involving lubrication and friction. The present paper deals with the tribological performance of hip implants and is organized in to three main sections. Firstly, the basic elements of tribology are presented, from contact mechanics of ball-in-socket joints to ultra high molecular weight polyethylene wear laws. Some fundamental equations are also reported, with the aim of providing the reader with some simple tools for tribological investigations. In the second section, the focus moves to artificial hip joints, defining materials and geometrical properties and discussing their friction, lubrication and wear characteristics. In particular, the features of different couplings, from metal-on-plastic to metal-on-metal and ceramic-on-ceramic, are discussed as well as the role of the head radius and clearance. How friction, lubrication and wear are interconnected and most of all how they are specific for each loading and kinematic condition is highlighted. Thus, the significant differences in patients and their lifestyles account for the high dispersion of clinical data. Furthermore, such consideration has raised a new discussion on the most suitable in vitro tests for hip implants as simplified gait cycles can be too far from effective implant working conditions. In the third section, the trends of hip implants in the years from 2003 to 2012 provided by the National Joint Registry of England, Wales and Northern Ireland are summarized and commented on in a discussion. PMID:25621213

  8. Nonablative skin resurfacing: the role of PDT.

    PubMed

    Ruiz-Rodriguez, Ricardo; López-Rodriguez, Laura

    2006-09-01

    As demand for less invasive, highly effective cosmetic procedures grows, dermatologists must continue to explore and develop new treatment options. Nonablative skin resurfacing techniques offer an effective and noninvasive treatment for photorejuvenation. Several studies have shown improvement of photodamaged skin and increased collagen production after nonablative treatments using vascular lasers, mid-infrared lasers, intense pulsed light, radiofrequency devices, fractional resurfacing, and plasma skin rejuvenation. Among the novel methods for maximizing the efficacy of nonablative treatment is the concurrent use of a photosensitizing agent. The light sources currently most used for photodynamic rejuvenation are intense pulsed light and pulsed dye laser. We present some preliminary results on rejuvenation using Metvix and red light. We are still far from a thorough understanding of the molecular mechanism of rejuvenation with this technique, although a nonspecific immune response could be involved. Understanding the laser-tissue interactions associated with photodynamic therapy is crucial in selecting patients that will most likely benefit.

  9. Activation of noble metals on metal-carbide surfaces: novel catalysts for CO oxidation, desulfurization and hydrogenation reactions.

    PubMed

    Rodriguez, José A; Illas, Francesc

    2012-01-14

    This perspective article focuses on the physical and chemical properties of highly active catalysts for CO oxidation, desulfurization and hydrogenation reactions generated by depositing noble metals on metal-carbide surfaces. To rationalize structure-reactivity relationships for these novel catalysts, well-defined systems are required. High-resolution photoemission, scanning tunneling microscopy (STM) and first-principles periodic density-functional (DF) calculations have been used to study the interaction of metals of Groups 9, 10 and 11 with MC(001) (M = Ti, Zr, V, Mo) surfaces. DF calculations give adsorption energies that range from 2 eV (Cu, Ag, Au) to 6 eV (Co, Rh, Ir). STM images show that Au, Cu, Ni and Pt grow on the carbide substrates forming two-dimensional islands at very low coverage, and three-dimensional islands at medium and large coverages. In many systems, the results of DF calculations point to the preferential formation of admetal-C bonds with significant electronic perturbations in the admetal. TiC(001) and ZrC(001) transfer some electron density to the admetals facilitating bonding of the adatom with electron-acceptor molecules (CO, O(2), C(2)H(4), SO(2), thiophene, etc.). For example, the Cu/TiC(001) and Au/TiC(001) systems are able to cleave both S-O bonds of SO(2) at a temperature as low as 150 K, displaying a reactivity much larger than that of TiC(001) or extended surfaces of bulk copper and gold. At temperatures below 200 K, Au/TiC is able to dissociate O(2) and perform the 2CO + O(2)→ 2CO(2) reaction. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(001) or Au(111), a Au/TiC(001) surface displays an activity for the hydrodesulfurization of thiophene higher than that of conventional Ni/MoS(x) catalysts. In general, the Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces. Thus, metal carbides are excellent supports for enhancing the chemical

  10. Is increased modularity associated with increased fretting and corrosion damage in metal-on-metal total hip arthroplasty devices?: a retrieval study.

    PubMed

    Higgs, Genymphas B; Hanzlik, Josa A; MacDonald, Daniel W; Gilbert, Jeremy L; Rimnac, Clare M; Kurtz, Steven M

    2013-09-01

    This retrieval study documents taper damage at modular interfaces in retrieved MOM THA systems and investigates if increased modularity is associated with increased fretting and corrosion. One hundred thirty-four (134) heads and 60 stems (41 modular necks) of 8 different bearing designs (5 manufacturers) were analyzed. Damage at the shell-liner interface of 18 modular CoCr acetabular liners and the corresponding 11 acetabular shells was also evaluated. The results of this study support the hypothesis that fretting and corrosion damage occurs at a variety of modular component interfaces in contemporary MOM THAs. We also found that modularity of the femoral stem was associated with increased damage at the head. An analysis of component and patient variables revealed that dissimilar alloy pairing, larger head sizes, increased medio-lateral offsets and longer neck moment arms were all associated with increased taper damage at the modular interfaces.

  11. Diagnosis and management of skin resurfacing-related complications.

    PubMed

    Zhang, Alexandra Y; Obagi, Suzan

    2009-02-01

    The field of skin resurfacing is undergoing rapid evolution with many new technologies that have developed, providing more choices for physicians and patients. Knowing the potential adverse effects associated with each skin resurfacing modality is paramount in selecting the appropriate approach for each candidate, thereby minimizing complications and achieving optimal results.

  12. Hip Fracture

    MedlinePlus

    ... make older people more likely to trip and fall — one of the most common causes of hip ... Taking steps to maintain bone density and avoid falls can help prevent hip fracture. Signs and symptoms ...

  13. Hip Replacement

    MedlinePlus

    ... replacement is an operation in which a damaged hip joint is removed and replaced with an artificial joint. ... are many medical conditions that can damage the hip joint. (Watch the video to learn about what goes ...

  14. Hip Ultrasound

    MedlinePlus

    ... Index A-Z Hip Ultrasound Hip ultrasound uses sound waves to produce pictures of muscles, tendons, ligaments, ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  15. Extended travel after hip arthroplasty surgery. Is it safe?

    PubMed

    Ball, Scott T; Pinsorsnak, Piya; Amstutz, Harlan C; Schmalzried, Thomas P

    2007-09-01

    Hip arthroplasty and extended travel are each recognized as risk factors for venous thromboembolism (VTE). The safety of travel after hip arthroplasty is currently unknown. Patients who had traveled more than 200 miles within 6 weeks of a hip arthroplasty or hip resurfacing were identified and contacted. All patients received VTE chemoprophylaxis with enoxaparin, dalteparin, fondaparinox, or warfarin. A total of 608 patients traveled an average of 1377 miles at an average of 6.5 days after surgery. Among these patients, 462 traveled by airplane, 143 by car, and 3 by train. There were no deaths, no symptomatic pulmonary embolisms, and only 5 (0.82%) symptomatic deep venous thromboses. Nine (1.5%) patients experienced bleeding complications. With chemical VTE prophylaxis, extended travel within 6 weeks of hip arthroplasty surgery is associated with a low rate of symptomatic deep venous thrombosis, with no known pulmonary embolisms and no deaths.

  16. Inflammatory pseudotumor of the hip: a complication of arthroplasty to be recognized by the radiologist*

    PubMed Central

    Boas, Raquel de Melo Santos Vilas; Madeira, Ivana Andrade; Lopes, Alexia Abuhid; Paiva, Edson Barreto; Rodrigues, André Soares

    2015-01-01

    Soft tissue complications following hip arthroplasty may occur either in cases of total hip arthroplasty or in hip resurfacing, a technique that has become popular in cases involving young patients. Both orthopedic and radiological literatures are now calling attention to these symptomatic periprosthetic soft tissue masses called inflammatory pseudotumors or aseptic lymphocytic vasculites-associated lesions. Pseudotumors are associated with pain, instability, neuropathy, and premature loosening of prosthetic components, frequently requiring early and difficult reoperation. Magnetic resonance imaging plays a relevant role in the evaluation of soft tissue changes in the painful hip after arthroplasty, ranging from early periprosthetic fluid collections to necrosis and more extensive tissue damage. PMID:26543283

  17. Inflammatory pseudotumor of the hip: a complication of arthroplasty to be recognized by the radiologist.

    PubMed

    Boas, Raquel de Melo Santos Vilas; Madeira, Ivana Andrade; Lopes, Alexia Abuhid; Paiva, Edson Barreto; Rodrigues, André Soares

    2015-01-01

    Soft tissue complications following hip arthroplasty may occur either in cases of total hip arthroplasty or in hip resurfacing, a technique that has become popular in cases involving young patients. Both orthopedic and radiological literatures are now calling attention to these symptomatic periprosthetic soft tissue masses called inflammatory pseudotumors or aseptic lymphocytic vasculites-associated lesions. Pseudotumors are associated with pain, instability, neuropathy, and premature loosening of prosthetic components, frequently requiring early and difficult reoperation. Magnetic resonance imaging plays a relevant role in the evaluation of soft tissue changes in the painful hip after arthroplasty, ranging from early periprosthetic fluid collections to necrosis and more extensive tissue damage.

  18. Current Status of Fractional Laser Resurfacing.

    PubMed

    Carniol, Paul J; Hamilton, Mark M; Carniol, Eric T

    2015-01-01

    Fractional lasers were first developed based on observations of lasers designed for hair transplantation. In 2007, ablative fractional laser resurfacing was introduced. The fractionation allowed deeper tissue penetration, leading to greater tissue contraction, collagen production and tissue remodeling. Since then, fractional erbium:YAG resurfacing lasers have also been introduced. These lasers have yielded excellent results in treating photoaging, acne scarring, and dyschromia. With the adjustment of microspot density, pulse duration, number of passes, and fluence, the surgeon can adjust the treatment effects. These lasers have allowed surgeons to treat patients with higher Fitzpatrick skin types (types IV to VI) and greater individualize treatments to various facial subunits. Immunohistochemical analysis has demonstrated remodeling effects of the tissues for several months, producing longer lasting results. Adjuvant treatments are also under investigation, including concomitant face-lift, product deposition, and platelet-rich plasma. Finally, there is a short recovery time from treatment with these lasers, allowing patients to resume regular activities more quickly. Although there is a relatively high safety profile for ablative fractionated lasers, surgeons should be aware of the limitations of specific treatments and the associated risks and complications.

  19. The Symmetry of Adverse Local Tissue Reactions in Patients with Bilateral Simultaneous and Sequential ASR Hip Replacement.

    PubMed

    Madanat, Rami; Hussey, Daniel K; Donahue, Gabrielle S; Potter, Hollis G; Wallace, Robert; Bragdon, Charles R; Muratoglu, Orhun K; Malchau, Henrik

    2015-10-01

    The purpose of this study was to evaluate whether patients with bilateral metal-on-metal (MoM) hip replacements have symmetric adverse local tissue reactions (ALTRs) at follow-up. An MRI of both hips was performed at a mean time of six years after surgery in 43 patients. The prevalence and severity of ALTRs were found to be similar in simultaneous hips but differences were observed in sequential hips. The order and timing of sequential hip arthroplasties did not affect the severity of ALTRs. Thus, in addition to metal ion exposure from an earlier MoM implant other factors may also play a role in the progression of ALTRs. Bilateral implants should be given special consideration in risk stratification algorithms for management of patients with MoM hip arthroplasty.

  20. Formation of a pseudotumor in total hip arthroplasty using a tribological metal-polyethylene pair.

    PubMed

    Fagotti, Lorenzo; Vicente, José Ricardo Negreiros; Miyahara, Helder Souza; de Oliveira, Pedro Vitoriano; Bernabé, Antônio Carlos; Croci, Alberto Tesconi

    2015-01-01

    The aim here was to report a case of a young adult patient who evolved with tumor formation in the left thigh, 14 years after revision surgery on hip arthroplasty. Davies in 2005 made the first description of this disease in patients undergoing metal-on-metal hip arthroplasty. Over the last decade, however, pseudotumors around metal-on-polyethylene surfaces have become more prevalent. Our patient presented with increased volume of the left thigh 8 years after hip arthroplasty revision surgery. Two years before the arising of the tumor in the thigh, a nodule in the inguinal region was investigated to rule out a malignant neoplastic process, but the results were inconclusive. The main preoperative complaints were pain, functional limitation and marked reduction in the range of motion of the left hip. Plain radiographs showed loosening of acetabular and femoral, and a large mass between the muscle planes was revealed through magnetic resonance imaging of the left thigh. The surgical procedure consisted of resection of the lesion and removal of the components through lateral approach. In respect of total hip arthroplasty, pseudotumors are benign neoplasms in which the bearing surface consists of metal-on-metal, but they can also occur in different tribological pairs, as presented in this case.

  1. Plasma skin resurfacing: personal experience and long-term results.

    PubMed

    Bentkover, Stuart H

    2012-05-01

    This article presents a comprehensive clinical approach to plasma resurfacing for skin regeneration. Plasma technology, preoperative protocols, resurfacing technique, postoperative care, clinical outcomes, evidence-based results, and appropriate candidates for this procedure are discussed. Specific penetration depth and specific laser energy measurements are provided. Nitrogen plasma skin regeneration is a skin-resurfacing technique that offers excellent improvement of mild to moderate skin wrinkles and overall skin rejuvenation. It also provides excellent improvement in uniformity of skin color and texture in patients with hyperpigmentation with Fitzpatrick skin types 1 through 4.

  2. The Emerging Resurfacing History of Europa

    NASA Astrophysics Data System (ADS)

    Figueredo, P.; Greeley, R.

    2002-12-01

    We have completed the geologic mapping and analysis of pole-to-pole transects across the leading and trailing hemispheres of Europa. Our results show that ~50% of the mapped areas has been resurfaced since the period of background ridged plains formation (comprising the last 50-100 Myr.): ~30% by tectonic processes and ~20% by chaotic disruption. Further, the geologic record indicates a transition from tectonic- to cryovolcanic-dominated resurfacing. The style of tectonic processes changed with time, from intensive, closely spaced fracturing and ridge building forming background plains, to infilling of inter-plate gaps forming broad bands, to gradually narrower and farther-spaced ridges and ridge complexes. In both hemispheres, these lineaments rotated with time in senses consistent with nonsynchronous rotation predictions. The lack of lineaments overprinting impact structures (with the exception of Tyre) suggests that the intensity of tectonic resurfacing decreased rapidly after the formation of ridged plains. Units associated with chaotic disruption overprint one another (in areas that broadly match regions where the regional thermal gradient has been raised by tidal dissipation), fragmenting the evidence for early cryovolcanic activity. Old, subdued chaos has been reworked to form younger chaos areas by merging of small patches of disruption; the most recent chaos features appear to be slightly elevated with respect to the surrounding plains. These observations suggest that chaos formed by disruption and emplacement of buoyant material from the subsurface, which became topographically and morphologically subdued with time. One possible interpretation of the mentioned trends and changes is the gradual thickening of Europa's lithosphere throughout the visible geologic history: the degree of fracturing and plate displacements decrease in a thickening shell, while lineaments become narrower and more widely spaced; formation of chaos regions can take place where the

  3. Liquid water and active resurfacing on Europa

    NASA Technical Reports Server (NTRS)

    Squyres, S. W.; Reynolds, R. T.; Cassen, P. M.; Peale, S. J.

    1983-01-01

    Arguments for recent resurfacing of Europa by H2O from a liquid layer are presented, based on new interpretations of recent spacecraft and earth-based observations and revised theoretical calculations. The heat flow in the core and shell due to tidal forces is discussed, and considerations of viscosity and convection in the interior are found to imply water retention in the outer 60 km or so of the silicates, forming a layer of water/ice many tens of km thick. The outer ice crust is considered to be too thin to support heat transport rates sufficient to freeze the underlying water. Observational evidence for the calculations would consist of an insulating layer of frosts derived from water boiling up between cracks in the surface crust. Evidence for the existence of such a frost layer, including the photometric function of Europa and the deposits of sulfur on the trailing hemisphere, is discussed.

  4. Erbium:YAG laser resurfacing using a novel portable device.

    PubMed

    Gordon, James; Khan, Misbah H; Khatri, Khalil A

    2007-05-01

    Laser resurfacing of facial rhytids has become a popular treatment for many patients who have wrinkles, photodamage, and acne scarring. Erbium:YAG laser resurfacing has emerged as one of the safer, more effective methods of facial rejuvenation and its increasing popularity has led to its widespread use for resurfacing. However, size and high initial and maintenance cost are among the problems with currently available laser devices. The LightPod portable Erbium:YAG laser from Aerolase offers a new paradigm for more cost effective means of performing ablative resurfacing with reduced initial and maintenance cost and the ease of portability with significantly reduced size and weight. The objective of this pilot study was to analyze the efficacy of The LightPod Erbium:YAG laser in different skin types for various indications.

  5. Hip arthroscopy.

    PubMed

    de Amorim Cabrita, Henrique Antônio Berwanger; de Castro Trindade, Christiano Augusto; de Campos Gurgel, Henrique Melo; Leal, Rafael Demura; de Souza Marques, Ricardo da Fonseca

    2015-01-01

    Hip arthroscopy is a safe method for treating a variety of pathological conditions that were unknown until a decade ago. Femoroacetabular impingement is the commonest of these pathological conditions and the one with the best results when treated early on. The instruments and surgical technique for hip arthroscopy continue to evolve. New indications for hip arthroscopy has been studied as the ligamentum teres injuries, capsular repair in instabilities, dissection of the sciatic nerve and repair of gluteal muscles tears (injuries to the hip rotator cuff), although still with debatable reproducibility. The complication rate is low, and ever-better results with fewer complications should be expected with the progression of the learning curve.

  6. Bearing surfaces in hip replacement – Evolution and likely future

    PubMed Central

    Kumar, Narinder; Arora, Gen N.C.; Datta, Barun

    2014-01-01

    Total hip arthroplasty has evolved from the first total hip arthroplasty in 1938, through the revolutionization of hip arthroplasty by principles of low friction arthroplasty introduced by Sir John Charnley in 1960s to the present state of the art implants and techniques. The main concern regarding failure of total hip arthroplasty has been the biological response to particulate polyethylene debris generated by conventional metal on polyethylene bearing surfaces leading to osteolysis and aseptic loosening of the prosthesis. Therefore, recent research has been focussing on alternative bearing surfaces to reduce the particulate debris generated. These bearing surfaces include ceramic-polyethylene, metal–metal as well as ceramic–ceramic articulations and have demonstrated lesser friction rates as well as significantly lower wear rates as compared to widely used metal on polyethylene surfaces. Clinical experience until now has shown that metal on metal articulations have significant safety concerns whereas metal-on-highly crosslinked polyethylene, ceramic on ceramic and ceramic on highly crosslinked polyethylene articulations have shown encouraging results to hold promise for wider use in younger and more active patients. This review article discusses positives and drawbacks of various bearing surfaces in current clinical use in total hip arthroplasty as well as briefly explores the newer technologies on the horizon which may even further decrease wear and improve total hip arthroplasty survivorship. PMID:25382913

  7. The influence of resting periods on friction in the artificial hip.

    PubMed

    Nassutt, Roman; Wimmer, Markus A; Schneider, Erich; Morlock, Michael M

    2003-02-01

    Insufficient tribologic performance of total joint components is a major cause of prostheses failure. Wear has been studied intensively using testing machines that apply continuous motions. Human locomotion, however, is not well represented by continuous motions alone. Singular events and resting periods are a substantial part of daily activities. Resting does influence adhesion in the artificial joint with possible effects on friction, wear, and loosening. The current study evaluated the effects of resting on the frictional properties of hip prosthesis components. The activity measurements of 32 patients with artificial hip replacements were analyzed for resting durations of the hip. A pin-on-ball screening device was used to determine friction after characteristic resting periods and during continuous oscillating motion. All common articulation pairings were investigated. Prolonged and frequent resting periods of the hip were found for the patients. Initial friction increased with increasing resting duration for all tested materials (between 41% and 191%). The metal-on-metal articulations showed the highest friction level (0.098 for sliding) and the highest increase (191%) in friction with resting duration (0.285 after resting periods of 60 seconds). A high static frictional moment after resting periods might present a risk for aseptic implant loosening. Therefore, large head diameters of metal-on-metal joints should be used with caution, especially when additional unfavorable risk factors such as obesity, weak bone-implant interface, or high activity level are present.

  8. Investigation of Wear and Corrosion of a High-Carbon Stellite Alloy for Hip Implants

    NASA Astrophysics Data System (ADS)

    Hu, P. S.; Liu, R.; Liu, J.; McRae, G.

    2014-04-01

    Low-carbon Stellite 21 has been used as hip implant material for a number of decades; however, its limited metal-on-metal bearing has resulted in loosening between the femoral head and the acetabular cup of hip implants. In order to improve the metal-on-metal bearing, it is proposed that a high-carbon alloy, Stellite 720, surface coating be applied on Stellite 21 hip implants to improve mechanical and tribological performance. For this coating to be practical, it must also meet the requirements of corrosion resistance for orthopedic implant materials. In this research, Stellite 720 is investigated with pin-on-disk wear tests, and electrochemical and immersion corrosion tests in simulated human body fluid (Hank's solution; pH 7.4 at temperature of 37°C). The experimental results demonstrate that Stellite 720 exhibits much better wear resistance than Stellite 21, and has the potential for better corrosion resistance as well. The applicability of coating Stellite 21 hip implants with Stellite 720 is discussed.

  9. Fractional carbon dioxide laser and plasmakinetic skin resurfacing.

    PubMed

    Groff, William F; Fitzpatrick, Richard E; Uebelhoer, Nathan S

    2008-12-01

    Photodamage is one of the most common reasons that patients visit a dermatologist's office. Carbon dioxide (CO(2)) laser resurfacing has always been the gold standard for reversing photodamage. Because of the relatively high incidence of side effects and the prolonged downtime associated with CO(2) resurfacing, new technologies have emerged to address photodamage. Portrait skin regeneration (PSR) is a novel device that has been developed to treat photodamage, and this device yields fewer side effects and downtime than traditional CO(2) laser resurfacing. At our center, we have performed more than 500 high-energy PSR treatments and have developed a unique and highly effective treatment protocol. In addition, fractional CO(2) laser resurfacing has emerged as the latest technology developed to combat photoaging. This technology yields impressive results and is much safer and causes less downtime than traditional CO(2) laser resurfacing. In this article, we will review our treatment techniques and protocols as well as address patient selection, preoperative and postoperative care, and anesthesia.

  10. Time series trends of the safety effects of pavement resurfacing.

    PubMed

    Park, Juneyoung; Abdel-Aty, Mohamed; Wang, Jung-Han

    2017-04-01

    This study evaluated the safety performance of pavement resurfacing projects on urban arterials in Florida using the observational before and after approaches. The safety effects of pavement resurfacing were quantified in the crash modification factors (CMFs) and estimated based on different ranges of heavy vehicle traffic volume and time changes for different severity levels. In order to evaluate the variation of CMFs over time, crash modification functions (CMFunctions) were developed using nonlinear regression and time series models. The results showed that pavement resurfacing projects decrease crash frequency and are found to be more safety effective to reduce severe crashes in general. Moreover, the results of the general relationship between the safety effects and time changes indicated that the CMFs increase over time after the resurfacing treatment. It was also found that pavement resurfacing projects for the urban roadways with higher heavy vehicle volume rate are more safety effective than the roadways with lower heavy vehicle volume rate. Based on the exploration and comparison of the developed CMFucntions, the seasonal autoregressive integrated moving average (SARIMA) and exponential functional form of the nonlinear regression models can be utilized to identify the trend of CMFs over time.

  11. Hip arthroscopy

    MedlinePlus

    Johnson D, Weiss WM. Basic arthroscopic principles. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic ... 11. Sanchez VMI, Meza AO. Hip arthroscopy. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic ...

  12. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  13. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  14. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  15. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  16. Nonablative fractional laser resurfacing in Asian skin--a review.

    PubMed

    Sachdeva, Silonie

    2010-12-01

    Skin resurfacing has been a part of cosmetic dermatology for more than two decades now, and most of it has been ablative with traditional aggressive lasers including the CO(2) and erbium. The last few years have seen a revolutionary change with the invention of nonablative lasers for skin tightening. Fractional resurfacing is a new concept of cutaneous remodeling whereby laser-induced zones of microthermal injury are surrounded by normal untreated tissue that helps in quicker healing. The various wavelengths used are 1320, 1440, and 2940 nm with depth of penetration ranging from 25 μ to 1.2 mm. This article reviews the history of nonablative fractional laser resurfacing, its indications, contraindications, and a review of use in Asian skin with Fitzpatrick type III-VI.

  17. Why does carbon dioxide resurfacing work? A review.

    PubMed

    Ross, E V; McKinlay, J R; Anderson, R R

    1999-04-01

    Despite the unquestionable efficacy of carbon dioxide laser skin resurfacing, mechanisms for cosmetic enhancement remain poorly characterized. Histological studies have provided some insight into the cascade of events from initial laser impact to final skin rejuvenation. However, there are few comprehensive studies of gross and microscopic wound healing. Additionally, the literature is fragmented; excellent individual articles appear in journals from widely disparate disciplines. For example, some reports relevant to laser skin resurfacing are "sequestered" in the engineering literature. This article is intended to update the physician on laser skin resurfacing based on the broadest review of the current literature. It proceeds from a discussion of initial laser-tissue interactions, such as collagen denaturation, to examination of long-term biological sequelae. At some cost to scientific rigor, mathematical models describing laser-tissue interactions are not presented.

  18. The Latest Lessons Learned from Retrieval Analyses of Ultra-High Molecular Weight Polyethylene, Metal-on-Metal, and Alternative Bearing Total Disc Replacements.

    PubMed

    Kurtz, Steven M; Toth, Jeffrey M; Siskey, Ryan; Ciccarelli, Lauren; Macdonald, Dan; Isaza, Jorge; Lanman, Todd; Punt, Ilona; Steinbeck, Marla; Goffin, Jan; van Ooij, André

    2012-03-01

    Knowledge regarding the in vivo performance and periposthetic tissue response of cervical and lumbar total disc replacements (TDRs) continues to expand. This review addresses the following four main questions: 1) What are the latest lessons learned from polyethylene in large joints and how are they relevant to current TDRs? 2) What are the latest lessons learned regarding adverse local tissue reactions from metal-on-metal, CoCr bearings in large joints and how are they relevant to current TDRs? 3) What advancements have been made in understanding the in vivo performance of alternative biomaterials, such as stainless steel and polycarbonate urethane, for TDRs in the past five years? 4) How has retrieval analysis of all these various artificial disc bearing technologies advanced the state of the art in preclinical testing of TDRs? The study of explanted artificial discs and their associated tissues can help inform bearing selection as well as the design of future generations of disc arthroplasty. Analyzing retrieved artificial discs is also essential for validating preclinical test methods.

  19. Alternative materials to improve total hip replacement tribology.

    PubMed

    Santavirta, Seppo; Böhler, Max; Harris, William H; Konttinen, Yrjö T; Lappalainen, Reijo; Muratoglu, Orhun; Rieker, Claude; Salzer, Martin

    2003-08-01

    An improvement in tribology of bearing surfaces is an effective means of increasing the longevity of total hip replacement (THR). Currently, 3 approaches are available to achieve this aim: first, use of highly cross-linked UHMWPE; second, aluminum oxide ceramic bearings, and third, metal-on-metal bearings. Cross-linking reduces the wear resistance of UHMWPE markedly without impairment of other significant properties of the material. Simulator studies and some clinical long-term (10-22 years) follow-up surveys suggest an almost immeasurable wear of the highly cross-linked UHMWPE-based acetabular components during an expected clinical life span. Bioinert alumina ceramic (aluminum oxide) was introduced 3 decades ago for THR-bearing surfaces to improve performance and longevity. Alumina ceramic is entirely biostable and bioinert and has good mechanical properties. For correctly positioned alumina-on-alumina bearings, the annual linear wear rate has been reported to be 3.9 microm. Alumina heads have been successfully used in combination with polyethylene sockets, but as regards wear, the best results have been obtained with alumina-on-alumina bearings. In ceramic THR bearings, precise manufacture and contact surface geometry, including optimal clearance, are most important. For the currently available products, the component fracture risk is almost nonexistent (less than 1 per 1000). Metal-on-metal bearings were used in the early stage of THR surgery, although not all old designs were successful. More recent analyses of the early series have shown the advantages of metal-on-metal to be better and have led to a renaissance of this articulation. Initially, stainless steel was used because it was easy to manufacture and polish. Current metal-on-metal bearings are based on cobalt-chromium-molybdenum alloys with varying carbon contents. Such bearings are self-polishing. Linear wear rates remain at the level of a few microm a year. An improvement in technology has increased

  20. The resurfacing history of Venus: Constraints from buffered crater densities

    NASA Astrophysics Data System (ADS)

    Kreslavsky, Mikhail A.; Ivanov, Mikhail A.; Head, James W.

    2015-04-01

    Because of atmospheric shielding and endogenic resurfacing, the population of impact craters on Venus is small (about a thousand) and consists of large craters. This population has been used in numerous studies with the goal of deciphering the geologic and geodynamic history of Venus, but the nearly spatially random nature of the crater population has complicated efforts to understand this history. Here we utilize the recent 1:15 M-scale global geological map of Venus (Ivanov, M.A., Head, J.W. [2011]. Planet. Space Sci. 59, 1559-1600) to help address this problem. The global geological map provides a stratigraphic sequence of units, and known areas where each unit is exposed on the planet. For each crater on Venus we identify the specific geological units predating and postdating the crater. We perform a statistical analysis of this set of observations with a buffered crater density approach, which rigorously and consistently takes into account the large size of craters and the fact that many craters are known to predate and/or postdate more than one unit. In this analysis we consider crater emplacement as random and resurfacing history as determined (although unknown). We obtain formal confidence intervals for the mean ages of geological units and the mean age differences between the pairs of units at the unit boundaries. We find that (1) size-frequency distributions of craters superposed on each unit are consistent with each other; (2) regional plains and stratigraphically older units have similar crater retention ages; (3) stratigraphically younger units have a mean crater retention age significantly younger than the regional plains. These findings are readily and consistently explained by global resurfacing scenarios and are difficult to reconcile with equilibrium resurfacing scenarios. Our analysis also shows that the latest recorded part of intensive resurfacing period lasted on the order of 10% of the mean surface age (tens of millions of years). The

  1. Hip Replacement

    MedlinePlus

    ... cemented and uncemented prostheses are comparable. However, more long-term data are available in the United States for hip replacements with cemented prostheses, because doctors have been using them ... period. Because it takes a long time for the natural bone to grow and ...

  2. Similar patient-reported outcomes and performance after total knee arthroplasty with or without patellar resurfacing

    PubMed Central

    Ali, Abdulemir; Lindstrand, Anders; Nilsdotter, Anna; Sundberg, Martin

    2016-01-01

    Background and purpose Knee pain after total knee arthroplasty (TKA) is not uncommon. Patellar retention in TKA is one cause of postoperative knee pain, and may lead to secondary addition of a patellar component. Patellar resurfacing in TKA is controversial. Its use ranges from 2% to 90% worldwide. In this randomized study, we compared the outcome after patellar resurfacing and after no resurfacing. Patients and methods We performed a prospective, randomized study of 74 patients with primary osteoarthritis who underwent a Triathlon CR TKA. The patients were randomized to either patellar resurfacing or no resurfacing. They filled out the VAS pain score and KOOS questionnaires preoperatively, and VAS pain, KOOS, and patient satisfaction 3, 12, and 72 months postoperatively. Physical performance tests were performed preoperatively and 3 months postoperatively. Results We found similar scores for VAS pain, patient satisfaction, and KOOS 5 subscales at 3, 12, and 72 months postoperatively in the 2 groups. Physical performance tests 3 months postoperatively were also similar in the 2 groups. No secondary resurfacing was performed in the group with no resurfacing during the first 72 months Interpretation Patellar resurfacing in primary Triathlon CR TKA is of no advantage regarding pain, physical performance, KOOS 5 subscales, or patient satisfaction compared to no resurfacing. None of the patients were reoperated with secondary addition of a patellar component within 6 years. According to these results, routine patellar resurfacing in primary Triathlon TKA appears to be unnecessary. PMID:27212102

  3. Ceramic materials as bearing surfaces for total hip arthroplasty.

    PubMed

    D'Antonio, James A; Sutton, Kate

    2009-02-01

    During the past decade, advances in total hip arthroplasty component design have produced implants with reliable clinical results in regard to fixation. The foremost unresolved challenge has been the development of bearing surfaces that can withstand the higher demands of younger and more active patients. New alternative bearings with superior wear characteristics that minimize debris include ceramic-on-ceramic, metal-on-metal, and highly cross-linked polyethylenes in combination with ceramic or metal. Alumina-on-alumina ceramic bearings are extremely hard and scratch resistant and provide superior lubrication and wear resistance compared with other bearing surfaces in clinical use. Survivorship revision for any reason for the alumina ceramic bearings at 10 years was significantly higher compared with metal-on-polyethylene. Bearings currently being studied because of their encouraging wear performance in the laboratory are an alumina matrix (82% alumina, 17% zirconia, 0.3% chromium oxide), zirconium oxide, and ceramic-on-cobalt-chromium.

  4. Pelvic position and movement during hip replacement.

    PubMed

    Grammatopoulos, G; Pandit, H G; da Assunção, R; Taylor, A; McLardy-Smith, P; De Smet, K A; Murray, D W; Gill, H S

    2014-07-01

    The orientation of the acetabular component is influenced not only by the orientation at which the surgeon implants the component, but also the orientation of the pelvis at the time of implantation. Hence, the orientation of the pelvis at set-up and its movement during the operation, are important. During 67 hip replacements, using a validated photogrammetric technique, we measured how three surgeons orientated the patient's pelvis, how much the pelvis moved during surgery, and what effect these had on the final orientation of the acetabular component. Pelvic orientation at set-up, varied widely (mean (± 2, standard deviation (sd))): tilt 8° (2sd ± 32), obliquity -4° (2sd ± 12), rotation -8° (2sd ± 14). Significant differences in pelvic positioning were detected between surgeons (p < 0.001). The mean angular movement of the pelvis between set-up and component implantation was 9° (sd 6). Factors influencing pelvic movement included surgeon, approach (posterior > lateral), procedure (hip resurfacing > total hip replacement) and type of support (p < 0.001). Although, on average, surgeons achieved their desired acetabular component orientation, there was considerable variability (2sd ± 16) in component orientation. We conclude that inconsistency in positioning the patient at set-up and movement of the pelvis during the operation account for much of the variation in acetabular component orientation. Improved methods of positioning and holding the pelvis are required.

  5. Laserpeel: a peeling concept revolution with laser resurfacing protocols

    NASA Astrophysics Data System (ADS)

    Tenenbaum, Alain

    2000-06-01

    The author who is inventor of EasyPeel then Laserpeel wants to introduce new ways to choose the right indications for patients asking for cosmetic surgery. A lifting is as if you take a shirt and want to reduce its size cutting it. A resurfacing is as if you put a shirt and want to iron it. A peeling was as if you changed the color and grain of the shirt. Laserpeel is as if you iron the shirt treated with amidon, transform the second hand shirt as new, up to date on with glance effect sand give it then a stretching disco new wave effect. So, indications of facial lifting decrease at the same speed at the increase of indications of 'LASERPEEL'. Laser CO2 resurfacing should reborn because the post redness appearance decreases in intensity and duration due to LASERPEEL. LASERPEEL should be considered too as a preventive therapy coupled with preventive treatment resulting from longevity tests.

  6. Ablative fractional laser resurfacing helps treat restrictive pediatric scar contractures.

    PubMed

    Krakowski, Andrew C; Goldenberg, Alina; Eichenfield, Lawrence F; Murray, Jill-Peck; Shumaker, Peter R

    2014-12-01

    Conventional management of debilitating pediatric scar contractures, including hand therapy and surgery, may often be beset by delayed treatment, suboptimal results, and additional surgical morbidity. Ablative fractional laser resurfacing is an emerging adjunctive procedural option for scar contractures because of its promising efficacy and safety profile. However, its use to improve function has not been studied in the pediatric population. Herein we report 2 pediatric patients with recalcitrant scar contractures, causing persistent functional deficits, treated with an ablative fractional laser protocol. Both patients experienced rapid and cumulative subjective and objective improvements in range of motion and function as measured by an independent occupational therapist without reported complications. We highlight ablative fractional laser resurfacing as a novel and promising tool in the management of function-limiting scar contractures in children and propose that the technique be incorporated into existing scar treatment paradigms, guided by future research.

  7. Nontuberculous Mycobacterial Infection after Fractionated CO2 Laser Resurfacing

    PubMed Central

    Culton, Donna A.; Miller, Becky A.; Miller, Melissa B.; MacKuen, Courteney; Groben, Pamela; White, Becky; Cox, Gary M.; Stout, Jason E.

    2013-01-01

    Nontuberculous mycobacteria are increasingly associated with cutaneous infections after cosmetic procedures. Fractionated CO2 resurfacing, a widely used technique for photorejuvenation, has been associated with a more favorable side effect profile than alternative procedures. We describe 2 cases of nontuberculous mycobacterial infection after treatment with a fractionated CO2 laser at a private clinic. Densely distributed erythematous papules and pustules developed within the treated area within 2 weeks of the laser procedure. Diagnosis was confirmed by histologic analysis and culture. Both infections responded to a 4-month course of a multidrug regimen. An environmental investigation of the clinic was performed, but no source of infection was found. The case isolates differed from each other and from isolates obtained from the clinic, suggesting that the infection was acquired by postprocedure exposure. Papules and pustules after fractionated CO2 resurfacing should raise the suspicion of nontuberculous mycobacterial infection. PMID:23628077

  8. Monte Carlo modeling of the resurfacing of Venus

    NASA Technical Reports Server (NTRS)

    Bullock, M. A.; Grinspoon, David H.; Head, James W., III

    1992-01-01

    We have developed a three-dimensional model of venusian resurfacing that employs Monte Carlo simulations of both impact cratering and volcanism. The model simulates the production of craters on Venus by using the observed mass distributions of Earth- and Venus-crossing asteroids and comets. Lava flows are modeled by an energy minimization technique to simulate the effects of local topography on the shape and extent of flows. The model is run under a wide range of assumptions regarding the scale and time evolution of volcanism on Venus. Regions of the parameter space that result in impact crater distributions and modifications that are currently observed will be explored to place limits on the possible volcanic resurfacing history of Venus.

  9. Monte Carlo computer simulations of Venus equilibrium and global resurfacing models

    NASA Technical Reports Server (NTRS)

    Dawson, D. D.; Strom, R. G.; Schaber, G. G.

    1992-01-01

    Two models have been proposed for the resurfacing history of Venus: (1) equilibrium resurfacing and (2) global resurfacing. The equilibrium model consists of two cases: in case 1, areas less than or equal to 0.03 percent of the planet are spatially randomly resurfaced at intervals of less than or greater than 150,000 yr to produce the observed spatially random distribution of impact craters and average surface age of about 500 m.y.; and in case 2, areas greater than or equal to 10 percent of the planet are resurfaced at intervals of greater than or equal to 50 m.y. The global resurfacing model proposes that the entire planet was resurfaced about 500 m.y. ago, destroying the preexisting crater population and followed by significantly reduced volcanism and tectonism. The present crater population has accumulated since then with only 4 percent of the observed craters having been embayed by more recent lavas. To test the equilibrium resurfacing model we have run several Monte Carlo computer simulations for the two proposed cases. It is shown that the equilibrium resurfacing model is not a valid model for an explanation of the observed crater population characteristics or Venus' resurfacing history. The global resurfacing model is the most likely explanation for the characteristics of Venus' cratering record. The amount of resurfacing since that event, some 500 m.y. ago, can be estimated by a different type of Monte Carolo simulation. To date, our initial simulation has only considered the easiest case to implement. In this case, the volcanic events are randomly distributed across the entire planet and, therefore, contrary to observation, the flooded craters are also randomly distributed across the planet.

  10. Ablative skin resurfacing with a novel microablative CO2 laser.

    PubMed

    Gotkin, Robert H; Sarnoff, Deborah S; Cannarozzo, Giovanni; Sadick, Neil S; Alexiades-Armenakas, Macrene

    2009-02-01

    Carbon dioxide (CO2) laser skin resurfacing has been a mainstay of facial rejuvenation since its introduction in the mid 1990s. Recently, a new generation of fractional or microablative CO2 lasers has been introduced to the marketplace. According to the concept of fractional photothermolysis, these lasers ablate only a fraction of the epidermal and dermal architecture in the treatment area. An array of microscopic thermal wounds is created that ablates the epidermis and dermis within very tiny zones; adjacent to these areas, the epidermis and dermis are spared. This microablative process of laser skin resurfacing has proven safe and effective not only for facial rejuvenation, but elsewhere on the body as well. It is capable of improving wrinkles, acne scars, and other types of atrophic scars and benign pigmented lesions associated with elastotic, sun-damaged skin. Because of the areas of spared epidermis and dermis inherent in a procedure that employs fractional photothermolysis, healing is more rapid compared to fully ablative CO2 laser skin resurfacing and downtime is proportionately reduced. A series of 32 consecutive patients underwent a single laser resurfacing procedure with the a new microablative CO2 laser. All patients were followed for a minimum of 6 months and were asked to complete patient satisfaction questionnaires; a 6 month postoperative photographic evaluation by an independent physician, not involved in the treatment, was also performed. Both sets of data were graded and reported on a quartile scale. Results demonstrated greater than 50% improvement in almost all patients with those undergoing treatment for wrinkles, epidermal pigment or solar elastosis deriving the greatest change for the better (>75%).

  11. Thermal injuries as a result of CO2 laser resurfacing.

    PubMed

    Grossman, A R; Majidian, A M; Grossman, P H

    1998-09-01

    CO2 laser resurfacing of the face for fine wrinkles has gained great popularity over a short period of time. The use of the CO2 laser has proven to be effective in reducing or eliminating fine wrinkles. This tool in the surgeon's armamentarium has been added to those of dermabrasion and chemical peel. The theoretical advantage of the use of the CO2 laser for resurfacing has been better accuracy and reportedly more control of the depth of penetration. The use of the CO2 laser has been welcomed by many cosmetic surgeons. Until now, there have been few reported cases of complications with the use of the CO2 laser. To many, this would sound too good to be true; unfortunately, that is the case. The CO2 laser is a high-energy machine that can indeed cause thermal injury. This thermal injury can result in deep burns to the skin and hypertrophic scarring. We feel this is more common than is currently being reported, and we share our experience as a burn and wound care referral service. During an 18-month period, 20 consecutive patients were referred to our practice who had received injuries from the CO2 laser resurfacing laser. We present here in this review a summary of those injuries. The CO2 resurfacing laser is a very effective tool for the treatment of fine wrinkles, but it is not without the potential for serious complications. We urge caution with the use of the laser and prompt recognition and treatment of thermal injury to the skin.

  12. In-situ electrochemical study of interaction of tribology and corrosion in artificial hip prosthesis simulators.

    PubMed

    Yan, Yu; Dowson, Duncan; Neville, Anne

    2013-02-01

    The second generation Metal-on-Metal (MoM) hip replacements have been considered as an alternative to commonly used Polyethylene-on-Metal (PoM) joint prostheses due to polyethylene wear debris induced osteolysis. However, the role of corrosion and the biofilm formed under tribological contact are still not fully understood. Enhanced metal ion concentrations have been reported widely from hair, blood and urine samples of patients who received metal hip replacements and in isolated cases when abnormally high levels have caused adverse local tissue reactions. An understanding of the origin of metal ions is really important in order to design alloys for reduced ion release. Reciprocating pin-on-plate wear tester is a standard instrument to assess the interaction of corrosion and wear. However, more realistic hip simulator can provide a better understanding of tribocorrosion process for hip implants. It is very important to instrument the conventional hip simulator to enable electrochemical measurements. In this study, simple reciprocating pin-on-plate wear tests and hip simulator tests were compared. It was found that metal ions originated from two sources: (a) a depassivation of the contacting surfaces due to tribology (rubbing) and (b) corrosion of nano-sized wear particles generated from the contacting surfaces.

  13. Resurfacing Damaged Articular Cartilage to Restore Compressive Properties

    PubMed Central

    Grenier, Stephanie; Donnelly, Patrick E.; Gittens, Jamila; Torzilli, Peter A.

    2014-01-01

    Surface damage to articular cartilage is recognized as the initial underlying process causing the loss of mechanical function in early-stage osteoarthritis. In this study, we developed structure-modifying treatments to potentially prevent, stabilize or reverse the loss in mechanical function. Various polymers (chondroitin sulfate, carboxymethylcellulose, sodium hyaluronate) and photoinitiators (riboflavin, irgacure 2959) were applied to the surface of collagenase-degraded cartilage and crosslinked in situ using UV light irradiation. While matrix permeability and deformation significantly increased following collagenase-induced degradation of the superficial zone, resurfacing using tyramine-substituted sodium hyaluronate and riboflavin decreased both values to a level comparable to that of intact cartilage. Repetitive loading of resurfaced cartilage showed minimal variation in the mechanical response over a 7 day period. Cartilage resurfaced using a low concentration of riboflavin had viable cells in all zones while a higher concentration resulted in a thin layer of cell death in the uppermost superficial zone. Our approach to repair surface damage initiates a new therapeutic advance in the treatment of injured articular cartilage with potential benefits that include enhanced mechanical properties, reduced susceptibility to enzymatic degradation and reduced adhesion of macrophages. PMID:25468298

  14. Group C streptococcal septic arthritis of a prosthetic hip joint following dental treatment.

    PubMed

    Al-Himdani, Sarah; Woodnutt, David

    2015-10-22

    We report a case of a prosthetic joint infection occurring secondary to group C Streptococcus following dental treatment in a 66-year-old woman. This patient presented 11 years following a right hip resurfacing procedure with increasing pain and difficulty mobilising the right hip. An ultrasound and MRI scan identified a collection in the right hip joint, which was subsequently aspirated. Cultures revealed a group C Streptococcus. Extensive washout and surgical debridement of the hip joint was undertaken and the patient was treated with a protracted course of antibiotics. At 1 year follow-up, the patient demonstrated no evidence of recurrent infection. We discuss the evidence underlying prophylactic antibiotic usage regarding dental procedures in the prevention of septic arthritis in patients with prosthetic joints. We also review the spectrum of diseases caused by this organism.

  15. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  16. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  17. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  18. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  19. Total hip arthroplasty.

    PubMed Central

    Siopack, J S; Jergesen, H E

    1995-01-01

    Total hip arthroplasty, or surgical replacement of the hip joint with an artificial prosthesis, is a reconstructive procedure that has improved the management of those diseases of the hip joint that have responded poorly to conventional medical therapy. In this review we briefly summarize the evolution of total hip arthroplasty, the design and development of prosthetic hip components, and the current clinical indications for this procedure. The possible complications of total hip arthroplasty, its clinical performance over time, and future directions in hip replacement surgery are also discussed. Images PMID:7725707

  20. Recontouring, resurfacing, and scar revision in skin cancer reconstruction.

    PubMed

    Brenner, Michael J; Perro, Christopher A

    2009-08-01

    Residual disfigurement is a common problem for patients who have undergone skin cancer reconstruction. Restoring form and function in these patients is an artistic and technical endeavor. The efficacy of surgical scar revision, dermabrasion, chemical peels, and laser resurfacing is predicated upon the skin's innate ability to regenerate over time in response to mechanical, chemical, and thermal or ablative stresses. The patient and surgeon should be accepting of a process that is often gradual and may proceed in stages. Achieving proficiency with the secondary procedures for improving scars and local flaps may allow the motivated surgeon to mold an initially passable surgical result into an excellent one.

  1. Conditioning in laser skin resurfacing - betulin emulsion and skin recovery.

    PubMed

    Metelmann, Hans-Robert; Podmelle, Fred; Waite, Peter D; Müller-Debus, Charlotte Friederieke; Hammes, Stefan; Funk, Wolfgang

    2013-04-01

    Laser skin resurfacing of the face by CO₂-laser ablation is causing superficial wounds that need rapid recovery to reduce the risk of infection, the risk of chronification and as a result the risk of unaesthetic scars. The question being addressed by this study is to demonstrate benefit of betulin emulsion skin care after CO₂-laser wounds. The outcome of this aesthetic comparison between betulin emulsion, moist wound dressing and gauze covering in promoting the recovery process in laser skin ablation is to demonstrate improved aesthetic benefit for the patient.

  2. Clinically insignificant trunnionosis in large-diameter metal-on-polyethylene total hip arthroplasty

    PubMed Central

    Kendoff, D.; Lausmann, C.; Henckel, J.; Gehrke, T.; Skinner, J.; Hart, A.

    2017-01-01

    Objectives Mechanical wear and corrosion at the head-stem junction of total hip arthroplasties (THAs) (trunnionosis) have been implicated in their early revision, most commonly in metal-on-metal (MOM) hips. We can isolate the role of the head-stem junction as the predominant source of metal release by investigating non-MOM hips; this can help to identify clinically significant volumes of material loss and corrosion from these surfaces. Methods In this study we examined a series of 94 retrieved metal-on-polyethylene (MOP) hips for evidence of corrosion and material loss at the taper junction using a well published visual grading method and an established roundness-measuring machine protocol. Hips were retrieved from 74 male and 20 female patients with a median age of 57 years (30 to 76) and a median time to revision of 215 months (2 to 324). The reasons for revision were loosening of both the acetabular component and the stem (n = 29), loosening of the acetabular component (n = 58) and infection (n = 7). No adverse tissue reactions were reported by the revision surgeons. Results Evidence of corrosion was observed in 55% of hips. The median Goldberg taper corrosion score was 2 (1 to 4) and the annual rate of material loss at the taper was 0.084 mm3/year (0 to 0.239). The median trunnion corrosion score was 1 (1 to 3). Conclusions We have reported a level of trunnionosis for MOP hips with large-diameter heads that were revised for reasons other than trunnionosis, and therefore may be clinically insignificant. Cite this article: H. S. Hothi, D. Kendoff, C. Lausmann, J. Henckel, T. Gehrke, J. Skinner, A. Hart. Clinically insignificant trunnionosis in large-diameter metal-on-polyethylene total hip arthroplasty. Bone Joint Res 2017;6:52–56. DOI: 10.1302/2046-3758.61.BJR-2016-0150.R2. PMID:28108481

  3. Thermal measurements of short-duration CO2 laser resurfacing

    NASA Astrophysics Data System (ADS)

    Harris, David M.; Fried, Daniel; Reinisch, Lou; Bell, Thomas; Lyver, Rex

    1997-05-01

    The thermal consequences of a 100 microsecond carbon-dioxide laser used for skin resurfacing were examined with infrared radiometry. Human skin was evaluated in a cosmetic surgery clinic and extirpated rodent skin was measured in a research laboratory. Thermal relaxation following single pulses of in vivo human and ex vivo animal skin were quantitatively similar in the 30 - 1000 msec range. The thermal emission from the area of the irradiated tissue increased monotonically with increasing incident laser fluence. Extremely high peak temperatures during the 100 microsecond pulse are attributed to plume incandescence. Ejecta thermal emission may also contribute to our measurements during the first several msecs. The data are combined into a thermal relaxation model. Given known coefficients, and adjusting tissue absorption to reflect a 50% water content, and thermal conductivity of 2.3 times that of water, the measured (both animal back and human forearm) and calculated values coincide. The high thermal conductance suggests preferential thermal conduction along the protein matrix. The clinical observation of a resurfacing procedure clearly shows thermal overlap and build-up is a result of sequential, adjacent pulses. A decrease of 4 - 6 degrees Celsius in surface temperature at the treatment site that appeared immediately post-Tx and gradually diminished over several days is possibly a sign of dermal convective and/or evaporative cooling.

  4. Total hip arthroplasty in the ankylosed hip.

    PubMed

    Swanson, Megan A; Huo, Michael H

    2011-12-01

    Altered biomechanics secondary to hip ankylosis often result in degeneration of the lumbar spine, ipsilateral knee, and contralateral hip and knee. Symptoms in these joints may be reduced with conversion total hip arthroplasty (THA) of the ankylosed hip. THA in the ankylosed hip is a technically challenging procedure, and the overall clinical outcome is generally less satisfactory than routine THA performed for osteoarthritis and other etiologies. Functional integrity of the hip abductor muscles is the most important predictor of walking ability following conversion THA. Many patients experience persistent limp, and it can take up to 2 years to fully assess final functional outcome. Risk factors cited for increased risk of failed THA include prior surgical ankylosis and age <50 years at the time of conversion THA.

  5. Does patella resurfacing really matter? Pain and function in 972 patients after primary total knee arthroplasty

    PubMed Central

    Espehaug, Birgitte; Havelin, Leif Ivar; Vollset, Stein Emil; Furnes, Ove

    2010-01-01

    Background and purpose Resurfacing of the patella during primary total knee arthroplasty (TKA) is often recommended based on higher revision rates in non-resurfaced knees. As many of these revisions are insertions of a patella component due to pain, and since only patients with a non-resurfaced patella have the option of secondary resurfacing, we do not really know whether these patients have more pain and poorer function. The main purpose of the present paper was therefore to assess pain and function at least 2 years after surgery for unrevised primary non-resurfaced and resurfaced TKA, and secondary among prosthesis brands. Methods Information needed to calculate subscales from the knee injury and osteoarthritis outcome score (KOOS) was collected in a questionnaire given to 972 osteoarthritis patients with intact primary TKAs that had been reported to the Norwegian Arthroplasty Register. Pain and satisfaction on visual analog scales and improvement in EQ-5D index score ΔEQ-5D) were also used as outcomes. Outcomes were measured on a scale from 0 to 100 units (worst to best). To estimate differences in mean scores, we used multiple linear regression with adjustment for possible confounders. Results We did not observe any differences between resurfacing and non-resurfacing in any outcome, with estimated differences of ≤ 1.4 units and p-values of > 0.4. There was, however, a tendency of better results for the NexGen implant as compared to the reference brand AGC for symptoms (difference = 4.9, p = 0.05), pain (VAS) (difference = 8.3, p = 0.004), and satisfaction (VAS) (difference = 7.9, p = 0.02). However, none of these differences reached the stated level of minimal perceptible clinical difference. Interpretation Resurfacing of the patella has no clinical effect on pain and function after TKA. Differences between the brands investigated were small and they were assumed to be of minor importance. PMID:20158405

  6. Hip fracture surgery

    MedlinePlus

    ... neck fracture repair; Trochanteric fracture repair; Hip pinning surgery; Osteoarthritis-hip ... You may receive general anesthesia before this surgery. This means ... spinal anesthesia. With this kind of anesthesia, medicine is ...

  7. Hip replacement - discharge

    MedlinePlus

    ... surgery to replace all or part of your hip joint with an artificial joint called a prosthesis. This ... You're in the Hospital You had a hip joint replacement surgery to replace all or part of ...

  8. Hip joint injection

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007633.htm Hip joint injection To use the sharing features on this ... injection is a shot of medicine into the hip joint. The medicine helps relieve pain and inflammation. It ...

  9. The Hip Restoration Algorithm

    PubMed Central

    Stubbs, Allston Julius; Atilla, Halis Atil

    2016-01-01

    Summary Background Despite the rapid advancement of imaging and arthroscopic techniques about the hip joint, missed diagnoses are still common. As a deep joint and compared to the shoulder and knee joints, localization of hip symptoms is difficult. Hip pathology is not easily isolated and is often related to intra and extra-articular abnormalities. In light of these diagnostic challenges, we recommend an algorithmic approach to effectively diagnoses and treat hip pain. Methods In this review, hip pain is evaluated from diagnosis to treatment in a clear decision model. First we discuss emergency hip situations followed by the differentiation of intra and extra-articular causes of the hip pain. We differentiate the intra-articular hip as arthritic and non-arthritic and extra-articular pain as surrounding or remote tissue generated. Further, extra-articular hip pain is evaluated according to pain location. Finally we summarize the surgical treatment approach with an algorithmic diagram. Conclusion Diagnosis of hip pathology is difficult because the etiologies of pain may be various. An algorithmic approach to hip restoration from diagnosis to rehabilitation is crucial to successfully identify and manage hip pathologies. Level of evidence: V. PMID:28066734

  10. Hip Injuries and Disorders

    MedlinePlus

    ... problems. Osteoarthritis can cause pain and limited motion. Osteoporosis of the hip causes weak bones that break easily. Both of these are common in older people. Treatment for hip disorders may include rest, medicines, physical therapy, or surgery, including hip replacement.

  11. Hip Labral Tear

    MedlinePlus

    ... the outside rim of the socket of your hip joint. In addition to cushioning the hip joint, the labrum acts like a rubber seal or gasket to help hold the ball at the top of your thighbone securely within your hip socket. Athletes who participate in such sports as ...

  12. Ages of fracturing and resurfacing in the Amenthes region, Mars

    NASA Technical Reports Server (NTRS)

    Maxwell, Ted A.; Mcgill, George E.

    1988-01-01

    An attempt is made to determine whether there is any tectonic evidence in the relatively recent history of the boundary zone that will place contraints on the origin of the Martian dichotomy. It is found that the timing of resurfacing events and structural modification of outlier plateaus and mesas in the Martian eastern hemisphere provides a contraint on the history of tectonic events along the cratered terrain-northern plains boundary. The circumferential grabens surrounding the Isidis basin ceased forming before the final emplacement of ridged plains on the adjacent northern lowlands. The cratered plateau east of the Isidis basin includes two crater populations; stripping of the rims of craters was complete before downfalling of the transition zone between the cratered terrain and the northern plains, and a young population of craters on the plateau records the same age as the ridged plains units north of the boundary.

  13. MOLECULAR RESURFACING OF CARTILAGE WITH PROTEOGLYCAN 4 (PRG4)

    PubMed Central

    Chawla, Kanika; Ham, Hyun Ok; Nguyen, Trung; Messersmith, Phillip B.

    2010-01-01

    Early loss of proteoglycan 4 (PRG4), a lubricating glycoprotein implicated in boundary lubrication, from the cartilage surface has been associated with degeneration of cartilage and early onset of osteoarthritis. Viscosupplementation with hyaluronic acid and other macromolecules has been proposed as a treatment of osteoarthritis, however efficacy of viscosupplementation is variable and may be influenced by the short residence time of lubricant in the knee joint after injection. Recent studies have demonstrated the use of aldehyde (CHO) modified extracellular matrix proteins for targeted adherence to a biological tissue surface. We hypothesized that CHO could be exploited to enhance binding of lubricating proteoglycans to the surface of PRG4 depleted cartilage. The objective of this study was to determine the feasibility of molecular resurfacing of cartilage with aldehyde modified PRG4. PRG4 was chemically functionalized with aldehyde (PRG4-CHO), and aldehyde plus Oregon Green (OG) fluorophore (PRG4-OG-CHO) to allow for differentiation of endogenous and exogenous PRG4. Cartilage disks depleted of native PRG4 were then treated with solutions of PRG4, PRG4-CHO, or PRG4-OG-CHO and then assayed for the presence of PRG4 by immunohistochemistry, ELISA, and fluorescence imaging. Repletion of cartilage surfaces was significantly enhanced with the inclusion of CHO compared to repletion with unmodified PRG4. These findings suggest a generalized approach that may be used for molecular resurfacing of tissue surfaces with PRG4 and other lubricating biomolecules, perhaps leading in the future to a convenient method for overcoming loss of lubrication during the early stages of osteoarthritis. PMID:20338268

  14. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Classification. Class II. ...) translation in one or more planes. It has no linkage across-the-joint. This prosthesis is made of alloys, such as cobalt-chromium-molybdenum, and is intended to resurface one tibial condyle. The generic type...

  15. Fractionated laser resurfacing corrects the inappropriate UVB response in geriatric skin.

    PubMed

    Spandau, Dan F; Lewis, Davina A; Somani, Ally-Khan; Travers, Jeffrey B

    2012-06-01

    Non-melanoma skin cancer is a disease primarily afflicting geriatric patients as evidenced by the fact that 80% of all non-melanoma skin cancers are diagnosed in patients over the age of 60 years. As such, geriatric skin responds to cancer-inducing UVB irradiation in a manner that allows the establishment of tumor cells. Currently, the only effective treatment for non-melanoma skin cancer is the removal of the tumors after they appear, indicating the need for a more cost-effective prophylactic therapy. Geriatric volunteers were treated with fractionated laser resurfacing therapy on either sun-protected (upper buttocks) or chronically sun-exposed (dorsal forearm) skin. Fractionated laser resurfacing therapy was shown to decrease the occurrence of senescent fibroblasts in geriatric dermis, increase the dermal expression of IGF-1, and correct the inappropriate UVB response observed in untreated geriatric skin. These responses to fractionated laser resurfacing were equal to the effects seen previously using the more aggressive wounding following dermabrasion. Furthermore, fractionated laser resurfacing was equally effective in both sun-protected and sun-exposed skin. The ability of fractionated laser resurfacing treatment to protect against the occurrence of UVB-damaged proliferating keratinocytes indicates the potential of fractionated laser resurfacing to reduce or prevent aging-associated non-melanoma skin cancer.

  16. Evolution and future of surface replacement of the hip.

    PubMed

    Amstutz, H C; Grigoris, P; Dorey, F J

    1998-01-01

    Surface replacement is a bone-conserving alternative to total hip arthroplasty and is a significant development in the evolution of hip arthroplasty. Surface replacement with polyethylene bearings was largely abandoned, primarily because of component aseptic loosening caused by tissue reaction to high-volumetric polyethylene wear. For patients with osteonecrosis and collapse of the femoral head but with preservation of some acetabular articular cartilage, precision fit, hemisurface replacement of the femoral head only has emerged as the treatment of choice. The survivorship of our series of patients, performed in the 1981-84 era (average age, 32 years), has been 85% at 5 years, 67% at 10 years, and 42% at 16 years. In the absence of polyethylene, there has been no loosening. Revisions were for cartilage wear. The procedure is now much improved with instrumentation for non-trochanteric osteotomy approaches and off-the-shelf components in 1-mm increments. For arthritic hips, a new era of surface replacement has emerged. With metal-on-metal bearings, the volumetric wear has been reduced 20-100 times from those with polyethylene, and there is no penalty for the large ball size. The devices are now conservative on the acetabular as well as femoral side. Hybrid or all-cementless fixation is superior to earlier all-cemented devices. In those patients, the results with up to 4 years have been complication-free, with an absence of pain and a return to high functional levels, including participation in sports. Forty patients have received a Conserve Plus with interference fitting of the acetabular component with sintered beads to obtain fixation. Although the follow-up is short, surface replacement with the large ball size is extremely stable, and dislocation is rare.

  17. Implication of femoral stem on performance of articular surface replacement (ASR) XL total hip arthroplasty.

    PubMed

    Cip, Johannes; von Strempel, Archibald; Bach, Christian; Luegmair, Matthias; Benesch, Thomas; Martin, Arno

    2014-11-01

    Taper junctions of large diameter metal-on-metal femoral heads and femoral stems were described as metal ion generator due to accelerated wear and corrosion. However, literature about the Articular Surface Replacement (ASR) total hip arthroplasty (THA) invariably deals with stems manufactured by DePuy Orthopedics (Warsaw, IN, USA). Nothing is known whether different stems with common 12/14 mm tapers affect failure rate or ion release. 99 ASR THA (88 patients) implanted with CoxaFit or ARGE Geradschaft stems (K-Implant, Hannover, Germany) were retrospectively analyzed. After a mean follow-up of 3.5 years revision rate was 24.5%, mostly due to adverse reaction to metal debris (ARMD). CT scan revealed component loosening in 10.3% and pseudotumoral lesions in 12.6%. Elevated ion concentrations (>7 μg/l) were found in 38.6%.

  18. Molecular and immune toxicity of CoCr nanoparticles in MoM hip arthroplasty.

    PubMed

    Gill, Harinderjit S; Grammatopoulos, George; Adshead, Stephen; Tsialogiannis, Evagellos; Tsiridis, Eleftherios

    2012-03-01

    Theoretical, desirable features of second-generation metal-on-metal (MoM) hip prostheses have led to their widespread use. However, the bearing surfaces, consisting of complex cobalt-chromium alloys, are subject to wear and the release of cobalt and chromium (CoCr) nanoparticles. These nanoparticles can reduce cellular viability, induce DNA damage, lead to chromosomal aberrations, and possibly stimulate increased metal hypersensitivity. Clinically, the effects can be both local (soft-tissue reactions) and systemic (arthroprosthetic cobaltism). This review assesses the literature concerning the in vitro and in vivo cytotoxic, genotoxic, and immunotoxic effects of CoCr wear particles, which is increasingly important in view of the large number of MoM arthroplasties performed.

  19. Mixing and matching in ceramic-on-metal hip arthroplasty: an in-vitro hip simulator study.

    PubMed

    Affatato, Saverio; Spinelli, Michele; Squarzoni, Stefano; Traina, Francesco; Toni, Aldo

    2009-11-13

    The clinical success of second-generation metal-on-metal hip replacement and the good tribological performance of alumina ceramic revived an interest in hip articulation as a solution to reduce wear. This study was aimed at characterizing the wear behaviour of new hybrid ceramic-on-metal bearings. In particular, this study investigated the wear behaviour of ceramic-on-metal hip components (three different diameters configurations: 28, 32 and 36 mm), not specifically proposed to be coupled, in order to compare them with ceramic-on-ceramic, which is considered to be the gold standard for wear resistance. For this purpose, the weight loss over a standard wear simulation was monitored. Moreover, scanning electronic microscope observations were used to verify if any carbides removal, for the metallic components, triggered wears debris production promoting abrasive third-body wear. After five million cycles, our results showed significantly greater wear-in ceramic-on-metal compared with ceramic-on-ceramic, and significant greater wear for the 32-mm diameter compared with the 36-mm one. Our findings showed an increase in wear for the proposed hybrid specimens with respect to that of the ceramic-on-ceramic ones confirming that even in the case of ceramic-on-metal bearings, mixing and matching could not prove effective wear behaviour, not even comparable with that of the ceramic-on-ceramic gold standard. Wear patterns and roundness tolerances certainly discourage the coupling of components not specifically intended to be coupled. Unsuitable geometrical conformity could, in fact, result in a poor dynamic behaviour and lead to clinical failure.

  20. History of plains resurfacing in the Scandia region of Mars

    USGS Publications Warehouse

    Tanaka, Kenneth L.; Fortezzo, Corey M.; Hayward, Rosalyn K.; Rodriguez, J. Alexis P.; Skinner, James A.

    2011-01-01

    We present a preliminary photogeologic map of the Scandia region of Mars with the objective of reconstructing its resurfacing history. The Scandia region includes the lower section of the regional lowland slope of Vastitas Borealis extending about 500–1800 km away from Alba Mons into the Scandia sub-basin below −4800 m elevation. Twenty mapped geologic units express the diverse stratigraphy of the region. We particularly focus on the materials making up the Vastitas Borealis plains and its Scandia sub-region, where erosional processes have obscured stratigraphic relations and made the reconstruction of the resurfacing history particularly challenging. Geologic mapping implicates the deposition, erosion, and deformation/degradation of geologic units predominantly during Late Hesperian and Early Amazonian time (~3.6–3.3 Ga). During this time, Alba Mons was active, outflow channels were debouching sediments into the northern plains, and basal ice layers of the north polar plateau were accumulating. We identify zones of regional tectonic contraction and extension as well as gradation and mantling. Depressions and scarps within these zones indicate collapse and gradation of Scandia outcrops and surfaces at scales of meters to hundreds of meters. We find that Scandia Tholi display concentric ridges, rugged peaks, irregular depressions, and moats that suggest uplift and tilting of layered plains material by diapirs and extrusion, erosion, and deflation of viscous, sedimentary slurries as previously suggested. These appear to be long-lived features that both pre-date and post-date impact craters. Mesa-forming features may have similar origins and occur along the southern margin of the Scandia region, including near the Phoenix Mars Lander site. Distinctive lobate materials associated with local impact craters suggest impact-induced mobilization of surface materials. We suggest that the formation of the Scandia region features potentially resulted from crustal heating

  1. Volcanic eruptions on Io: Heat flow, resurfacing, and lava composition

    NASA Technical Reports Server (NTRS)

    Blaney, Diana L.; Johnson, Torrence V.; Matson, Dennis L.; Veeder, Glenn J.

    1995-01-01

    We model an infrared outburst on Io as being due to a large, erupting lava flow which increased its area at a rate of 1.5 x 10(exp 5)/sq m and cooled from 1225 to 555 K over the 2.583-hr period of observation. The inferred effusion rate of 3 x 10(exp 5) cu m/sec for this eruption is very high, but is not unprece- dented on the Earth and is similar to the high eruption rates suggested for early lunar volcanism. Eruptions occur approxi- mately 6% of the time on Io. These eruptions provide ample resurfacing to explain Io's lack of impact craters. We suggest that the large total radiometric heat flow, 10(exp 14) W, and the size and temperature distribution of the thermal anomalies (McEwen et al. 1992; Veeder et al. 1994) can be accounted for by a series of silicate lava flows in various stages of cooling. We propose that the whole suite of Io's currently observed thermal anomalies was produced by multiple, high-eruptive-rate silicate flows within the past century.

  2. Late Nontraumatic Dissociation of the Femoral Head and Trunnion in a Total Hip Arthroplasty

    PubMed Central

    Parker, Simon J. M.; Khan, Wasim; Mellor, Simon

    2015-01-01

    Background. Modular total hip arthroplasties are increasingly popular because customisation allows optimal restoration of patient biomechanics. However, the introduction of component interfaces provides greater opportunities for failure. We present a case of late nontraumatic dissociation of the head-neck interface, more than 10 years after insertion. Case Description. A 58-year-old woman had a left metal-on-metal total hip arthroplasty in 2002 for hip dysplasia. Following an uneventful 10-year period, she presented to hospital in severe pain after standing from a seated position, and radiographs demonstrated complete dissociation of the modular femoral head from the stem, with the femoral head remaining in its cup. There was no prior trauma or infection. Mild wear and metallosis were present on the articulating surface between the femoral head and trunnion. Soft tissues were unaffected. Discussion and Conclusions. This is the latest occurrence reported to date for nontraumatic component failure in such an implant by more than 7 years. The majority of cases occur in the context of dislocation and attempted closed reduction. We analyse and discuss possible mechanisms for failure, aiming to raise awareness of this potential complication and encouraging utmost care in component handling and insertion, as well as the long term follow-up of such patients. PMID:26078899

  3. Microscopical analysis of synovial fluid wear debris from failing CoCr hip prostheses

    NASA Astrophysics Data System (ADS)

    Ward, M. B.; Brown, A. P.; Cox, A.; Curry, A.; Denton, J.

    2010-07-01

    Metal on metal hip joint prostheses are now commonly implanted in patients with hip problems. Although hip replacements largely go ahead problem free, some complications can arise such as infection immediately after surgery and aseptic necrosis caused by vascular complications due to surgery. A recent observation that has been made at Manchester is that some Cobalt Chromium (CoCr) implants are causing chronic pain, with the source being as yet unidentified. This form of replacement failure is independent of surgeon or hospital and so some underlying body/implant interface process is thought to be the problem. When the synovial fluid from a failed joint is examined particles of metal (wear debris) can be found. Transmission Electron Microscopy (TEM) has been used to look at fixed and sectioned samples of the synovial fluid and this has identified fine (< 100 nm) metal and metal oxide particles within the fluid. TEM EDX and Electron Energy Loss Spectroscopy (EELS) have been employed to examine the composition of the particles, showing them to be chromium rich. This gives rise to concern that the failure mechanism may be associated with the debris.

  4. Hip Fractures among Older Adults

    MedlinePlus

    ... training for health care providers. Learn More Hip Fractures Among Older Adults Recommend on Facebook Tweet Share ... older. What You Can Do to Prevent Hip Fractures You can prevent hip fractures by taking steps ...

  5. Transient Synovitis of the Hip

    MedlinePlus

    ... inflammation and swelling of the tissues around the hip joint. Usually only one hip is affected. This condition ... to reduce the swelling and inflammation around the hip joint.Your child's doctor will probably ask you to ...

  6. Safety and efficacy of 2,790-nm laser resurfacing for chest photoaging.

    PubMed

    Grunebaum, Lisa D; Murdock, Jennifer; Cofnas, Paul; Kaufman, Joely

    2015-01-01

    Chest photodamage is a common cosmetic complaint. Laser treatment of the chest may be higher risk than other areas. The objective of this study was to assess the safety and efficacy of 2,790-nm chest resurfacing for photodamage. Twelve patients with Fitzpatrick skin types I-III were enrolled in this university IRB-approved study. Photo documentation was obtained at baseline and each visit. A test spot with the 2,790-nm resurfacing laser was performed on the chest. Patients who did not have adverse effects from the test spot went on to have a full chest resurfacing procedure. Patients were instructed on standardized aftercare, including sunscreen. A 5-point healing and photodamage improvement scale was used to rate improvement by both investigators and the patients and was obtained at 2 weeks, 1 month, 2 months, and 3 months. One pass chest treatment with the 2,790-nm resurfacing laser at fluences greater than or equal to 3.0 mJ with 10% overlap leads to unacceptable rates of hyperpigmentation. Double pass chest treatment at fluences less than or equal to 2.5 mJ with 10% overlap leads to mild improvement in chest photodamage parameters without significant or persistent adverse effects. Laser treatment of aging/photodamaged chest skin remains a challenge due to the delicacy of chest skin. Mild improvement may be obtained with double pass resurfacing with the 2,790-nm wavelength.

  7. Formed HIP Can Processing

    SciTech Connect

    Clarke, Kester Diederik

    2015-07-27

    The intent of this report is to document a procedure used at LANL for HIP bonding aluminum cladding to U-10Mo fuel foils using a formed HIP can for the Domestic Reactor Conversion program in the NNSA Office of Material, Management and Minimization, and provide some details that may not have been published elsewhere. The HIP process is based on the procedures that have been used to develop the formed HIP can process, including the baseline process developed at Idaho National Laboratory (INL). The HIP bonding cladding process development is summarized in the listed references. Further iterations with Babcock & Wilcox (B&W) to refine the process to meet production and facility requirements is expected.

  8. Clinical applications of CO2 laser resurfacing in the treatment of various pathologic skin disorders

    NASA Astrophysics Data System (ADS)

    Giler, Shamai

    1997-12-01

    CO2 laser skin resurfacing devices are widely used in cosmetic surgery for the treatment of facial rhytides, acne scars and aging skin. This technique is also useful in the treatment of various benign and premalignant or multiple pathological skin conditions and disorders originating in the epidermal, dermal and skin appendages, vascular lesions, epidermal nevi, infected wounds and ulcers, and keloids. Various surgical techniques have been developed in our clinic using laser resurfacing in the treatment of more than 2,000 patients with various skin pathologic disorders. We describe our experience with the various techniques used. The precise depth control and ablation properties combined with the hemostatic and sterilizing effects of the CO2 laser beam, reduction of the possibility of bleeding, infection and damage to healthy tissues, make the CO2 laser resurfacing techniques the treatment of choice for cosmetic surgery and treatment of benign, premalignant and multiple pathologic skin conditions.

  9. Re-epithelialization of the skin following CO2 laser resurfacing.

    PubMed

    Collawn, S S

    2001-09-01

    Wound healing following CO(2) laser resurfacing of the face is a complex process which must involve a rapid replacement of the ablated epidermis to protect the underlying structures in the skin from desiccation and deeper injury. The majority of cells that regenerate the epidermis come from the hair follicles, and cell movement out of the follicles is monitored using immunofluorescence with antibodies to keratin 17, an intermediate filament protein expressed in the migrating front of cells. This migration is enhanced with occlusive dressings used immediately after the resurfacing procedure. Skin biopsies have been examined at multiple time points following resurfacing, and re-epithelialization begins by 48 h in skin that has been occluded. Skin that has been left open with no treatment forms an eschar and has no keratinocyte migration at 48 h, thus displaying delayed wound healing.

  10. Venus resurfacing rates: Constraints provided by 3-D Monte Carlo simulations

    NASA Technical Reports Server (NTRS)

    Bullock, M. A.; Grinspoon, D. H.; Head, J. W.

    1993-01-01

    A 3-D Monte Carlo model that simulates the evolving surface of Venus under the influence of a flux of impacting objects and a variety of styles of volcanic resurfacing was implemented. For given rates of impact events and resurfacing, the model predicts the size-frequency and areal distributions of surviving impact craters as a function of time. The number of craters partially modified by volcanic events is also calculated as the surface evolves. It was found that a constant, global resurfacing rate of approximately 0.4 km(sup 3)/yr is required to explain the observed distributions of both the entire crater population, and the population of craters partially modified by volcanic processes.

  11. Liquid water and resurfacing of Enceladus' south polar terrain

    NASA Astrophysics Data System (ADS)

    Tobie, G.; Besserer, J.; Cadek, O.; Choblet, G.; Sotin, C.

    2008-09-01

    Enceladus are the only solid objects in the Solar System to be sufficiently geologically active for their internal heat to be detected by remote sensing. Interestingly, the endogenic activity on Enceladus is only located on a specific region at the south pole, from which jets of water vapor and ice particles have been observed ([1], [2]). The current polar location of the thermal anomaly can possibly be explained by diapirinduced reorientation of the satellite [3], but the triggering of the thermal anomaly and the heat power required to sustain it over geologic timescales remain problematic. Using a three-dimensional viscoelastic numerical model simulating the response of Enceladus to tidal forcing, we have demonstrated in a previous recent study [4] that only interior models with a liquid water layer at depth can explain the observed magnitude of dissipation and its particular location at the south pole (Fig. 1). Moreover, as tidally-induced heat must be generated over a relatively broad region in the southern hemisphere to explain the observed thermal emission, we proposed that this heat is then transferred toward the south polar terrain where it could be episodically released during relatively short resurfacing events. In the present study, we investigate the thermal stability of localized liquid water reservoir at the rock-ice interface by performing simulations of thermal convection in three-dimensional spherical geometry with the numerical tool OEDIPUS ([5],[6]) and by computing the corresponding dissipation pattern using the method developped in [4]. Where liquid water is present, a constant temperature equal to the melting temperature of water ice is prescribed at the base of the ice shell. Outside this region, a constant heat flux owing to the radiogenic power coming out of the silicate core is prescribed. Figure 2 illustrates the temperature field obtained for varying size of the liquid reservoir (ranging from 60o to 120o). These preliminary results

  12. Facial resurfacing with split-thickness skin grafts in xeroderma pigmentosum variant.

    PubMed

    Tayeb, Talel; Laure, Boris; Sury, Florent; Lorette, Gérard; Goga, Dominique

    2011-10-01

    Xeroderma Pigmentosum (XP) is a rare systemic disease which is transmitted through an incomplete sex-linked recessive gene. As a result of this, exposure to the ultraviolet (UV) rays of the sun causes malignant skin lesions. One of the most effective treatment options for the malignant lesions is full-face resurfacing with skin grafts. These grafts should be harvested from areas that have not been affected by UV exposure or have at least been minimally affected. The authors present a patient with XP whose face was resurfaced by split-thickness skin grafts taken from the buttocks.

  13. Safe and effective carbon dioxide laser skin resurfacing of the neck.

    PubMed

    Kilmer, Suzanne L; Chotzen, Vera A; Silva, Susan K; McClaren, Marla L

    2006-08-01

    CO2 laser skin resurfacing remains the gold standard for treatment of photoaged facial skin. It can be used onto the neck to further blend in the treated area with non-treated, adjacent photodamaged skin as well as improve the superficial textural quality of the neck skin. This article provides an overview of laser skin resurfacing of the neck, including pre-operative evaluation, patient education and selection, laser settings and technique used, post-operative care, and identification and treatment of possible complications.

  14. The resurfacing controversy for Venus: An overview and a mechanistic perspective

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.

    1993-01-01

    Two remarkable aspects of the population of impact craters on Venus are that craters at all sizes are indistinguishable from a random population and that most craters have not been significantly modified by tectonic strain or by volcanic flows external to the crater rim, despite evidence from Magellan images that volcanic and tectonic features are widespread on Venus. One interpretation of these observations is that most of the surface dates from the end of a catastrophic global resurfacing event that ceased about 500 My ago, and that a small fraction of craters volcaniclly embayed or modified by deformation indicate that volcanic and tectonic activity subsequent to that time has been at much lower levels. A competing scenario, in which resurfacing occurs episodically in patches a few hundred kilometers in extent and there is a wider spectrum of surface ages, also appears to be consistent with the characteristics of impact craters on Venus. While geological and statistical studies of the crater population on Venus offer some promise for distinguishing between these two hypotheses, consideration of the possible mechanisms of catastrophic episodic resurfacing provides an independent perspective. Potential mechanisms for catastrophic resurfacing of Venus range from geologically sudden convective destabilization of the global lithosphere to strongly time-dependent heat flux and melt generation in the underlying mantle. For most of these mechanisms, resurfacing occurs implicitly or explicitly by volcanism. An alternative hypothesis is that, at least in the geologically recent history of Venus, the primary resurfacing mechanism has been tectonic deformation rather than volcanism. Because the rate of surface strain should be controlled by the temperature-dependent strength of the lower crust, a geologically rapid transition in surface strain rates should be the natural result of planetary cooling. This transition would occur at comparable times for areas of similar

  15. Prevention of hip fractures.

    PubMed

    Meunier, P J

    1993-11-30

    For a 50-year old Caucasian woman today, the risk of a hip fracture over her remaining life-time is about 17%. Tomorrow the situation will clearly be worse because the continuous increase in life expectancy will cause a three-fold increase in worldwide fracture incidence over the next 60 years. Through diagnostic bone mass measurements at the hip and assessment of biochemical parameters, a great deal has been learned in recent years about reduction of hip fracture risk. Preventive strategies are based on prevention of falls, use of hip protectors, and prevention of bone fragility. The latter includes the optimization of peak bone mass during childhood, postmenopausal estrogen replacement therapy, and also late prevention consisting in reversing senile secondary hyperparathyroidism, which plays an important role in the decrease of skeletal strength. This secondary hyperparathyroidism, which results from both vitamin D insufficiency and low calcium intake, is preventable with vitamin D3 and calcium supplements. They have recently been shown capable of providing effective prevention of hip fractures in elderly women living in nursing homes, with a reduction of about 25% in the number of hip fractures noted in a 3-year controlled study in 3,270 women (intention-to-treat analysis). In conclusion, it is never too early to reduce the risk of osteoporosis and never too late to prevent hip fractures.

  16. Total Hip Replacement

    MedlinePlus

    ... ankle pump exercises, and early mobilization. Leg-length Inequality Sometimes after a hip replacement, one leg may ... Surgeons (AAOS). To learn more about your orthopaedic health, please visit orthoinfo.org. Page ( 12 ) AAOS does ...

  17. Ultrasound: Infant Hip

    MedlinePlus

    ... hip area, and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  18. HIP osteoarthritis and work.

    PubMed

    Harris, E Clare; Coggon, David

    2015-06-01

    Epidemiological evidence points strongly to a hazard of hip osteoarthritis from heavy manual work. Harmful exposures may be reduced by the elimination or redesign of processes and the use of mechanical aids. Reducing obesity might help to protect workers whose need to perform heavy lifting cannot be eliminated. Particularly high relative risks have been reported in farmers, and hip osteoarthritis is a prescribed occupational disease in the UK for long-term employees in agriculture. Even where it is not attributable to employment, hip osteoarthritis impacts importantly on the capacity to work. Factors that may influence work participation include the severity of disease, the physical demands of the job, age and the size of the employer. Published research does not provide a strong guide to the timing of return to work following hip arthroplasty for osteoarthritis, and it is unclear whether patients should avoid heavy manual tasks in their future employment.

  19. [Epidemiology of hip fracture].

    PubMed

    Hagino, Hiroshi

    2006-12-01

    Age- and gender-specific numbers of patients with hip fracture increase with age and peaked at the age 80-84; however, age- and gender-specific incidences increase exponentially with age. According to the recent nation-wide survey, the most common cause of hip fractures was a simple fall, 68.8% sustained fractures in-doors, and the incidences were higher in the winter than the summer period. More than 90% of patients with hip fracture were treated surgically and about 3/4 of patients with femoral neck fractures were treated with hemi-arthroplasty. Hip fractures for Asian people including Japanese are lower than those for Caucasians living in Northern Europe and North America; however, recent reports from the Asian area indicated an increase in the incidence with time.

  20. HIP OSTEOARTHRITIS AND WORK

    PubMed Central

    Harris, E Clare; Coggon, David

    2016-01-01

    Epidemiological evidence points strongly to a hazard of hip osteoarthritis from heavy manual work. Harmful exposures may be reduced by elimination or redesign of processes and use of mechanical aids. Reducing obesity might help to protect workers whose need to perform heavy lifting cannot be eliminated. Particularly high relative risks have been reported in farmers, and hip osteoarthritis is a prescribed occupational disease in the UK for long-term employees in agriculture. Even where it is not attributable to employment, hip osteoarthritis impacts importantly on capacity to work. Factors that may influence work participation include the severity of disease, the physical demands of the job, age, and the size of the employer. Published research does not provide a strong guide to the timing of return to work following hip arthroplasty for osteoarthritis, and it is unclear whether patients should avoid heavy manual tasks in their future employment. PMID:26612242

  1. Hip joint replacement

    MedlinePlus

    ... A socket, which is usually made of strong metal. A liner, which fits inside the socket. It ... are now trying other materials, like ceramic or metal. The liner allows the hip to move smoothly. ...

  2. Hip replacement in femoral head osteonecrosis: current concepts

    PubMed Central

    Scaglione, Michelangelo; Fabbri, Luca; Celli, Fabio; Casella, Francesco; Guido, Giulio

    2015-01-01

    Summary Osteonecrosis of the femoral head is a destructive disease that usually affects young adults with high functional demands and can have devastating effects on hip joint. The treatment depends on extent and location of the necrosis lesion and on patient’s factors, that suggest disease progression, collapse probability and also implants survival. Non-idiopathic osteonecrosis patients had the worst outcome. There is not a gold standard treatment and frequently it is necessary a multidisciplinary approach. Preservation procedures of the femoral head are the first choice and can be attempted in younger patients without head collapse. Replacement procedure remains the main treatment after failure of preserving procedures and in the late-stage ONFH, involving collapse of the femoral head and degenerative changes to the acetabulum. Resurfacing procedure still has good results but the patient selection is a critical factor. Total hip arthroplasties had historically poor results in patients with osteonecrosis. More recently, reports have shown excellent results, but implant longevity and following revisions are still outstanding problems. PMID:27134633

  3. The increase in cobalt release in metal-on-polyethylene hip bearings in tests with third body abrasives.

    PubMed

    de Villiers, Danielle; Traynor, Alison; Collins, Simon N; Shelton, Julia C

    2015-09-01

    Hypersensitivity reactions in patients receiving metal-on-metal hip replacements have been attributed to corrosion products as observed by elevated cobalt and chromium ions in the blood. Although the majority of cases are reported in metal-on-metal, incidences of these reactions have been reported in the metal-on-polyethylene patient population. To date, no in vitro study has considered cobalt release for this bearing combination. This study considered four 28 mm and seven 52 mm diameter metal-on-polyethylene bearings tested following ISO standard hip simulator conditions as well as under established abrasive conditions. These tests showed measurable cobalt in all bearings under standard conditions. Cobalt release, as well as polyethylene wear, increased with diameter, increasing from 52 to 255 ppb. The introduction of bone cement particles into the articulation doubled polyethylene wear and cobalt release while alumina particles produced significant damage on the heads demonstrated by cobalt levels of 70,700 ppb and an increased polyethylene wear from a mean value of 9-160 mm(3)/mc. Cobalt release was indicative of head damage and correlated with polyethylene wear at the next gravimetric interval. The removal of third body particles resulted in continued elevated cobalt levels in the 52 mm diameter bearings tested with alumina compared to standard conditions but the bearings tested with bone cement particles returned to standard levels. The polyethylene wear in the bone cement tested bearings also recovered to standard levels, although the alumina tested bearings continued to wear at a higher rate of 475 mm(3)/mc. Cobalt release was shown to occur in metal-on-polyethylene bearings indicating damage to the metal head resulting in increased polyethylene wear. While large diameter metal-on-polyethylene bearings may provide an increased range of motion and a reduced dislocation risk, increased levels of cobalt are likely to be released and this needs to be fully

  4. HIP ARTHROSCOPY IN ATHLETES

    PubMed Central

    Polesello, Giancarlo Cavalli; Keiske Ono, Nelson; Bellan, Davi Gabriel; Honda, Emerson Kiyoshi; Guimarães, Rodrigo Pereira; Junior, Walter Riccioli; Do Val Sella, Guilherme

    2015-01-01

    To confirm the therapeutic importance of hip arthroplasty in athletes whose pain precludes sportive function of the hip joint, being able to minimize it to the extent of helping on the return of sports practice at satisfactory levels. Methods: 49 athlete patients (51 hips) submitted to hip arthroscopy complaining of pain and inability to practice sports were assessed. Follow-up time ranged from 12 to 74 months (mean: 39.0 months). Preoperatively, pain site, severity according to Facial Expression Scale (FES) and the degree of disability using the modified Harris Hip Score (HHS) were assessed. Different diagnoses were provided, which led to the indication of arthroscopy, such as femoralacetabular impact, acetabular lip injury not secondary to femoral-acetabular impact, etc. Postoperatively, the patients were assessed by using the same methods as used at baseline and by the subjective analysis of return to sports activities. Results: Based on pre-and postoperative HHS and FES, the statistical analysis showed significance between values. We found some improvement in all cases and return to sports activities at a satisfactory level in most of the cases. Conclusion: As a result of our study, we confirm that arthroscopy in athletes with local hip injuries is an effective technique, able to promote the return to sports practice in most of the cases, without pain, and with an effective joint function, provided well indicated. PMID:26998449

  5. Ultrasonography of the hip.

    PubMed

    Nestorova, Rodina; Vlad, Violeta; Petranova, Tzvetanka; Porta, Francesco; Radunovic, Goran; Micu, Mihaela C; Iagnocco, Annamaria

    2012-09-01

    A complete physical examination of the hip is often difficult due to its size and deep position. During the last two decades, ultrasonography (US) of the hip has been widely accepted as a useful diagnostic tool in patients with hip pain and /or limited range of motion. It is commonly used in both adults and children. This technique allows evaluation of different anatomical structures and their pathological changes, such as joint recess (joint effusion, synovial hypertrophy), changes within the bursae (bursitis), tendons and muscles (tendinopathy, ruptures, calcifications), as well as changes in the bony profile of the joint surfaces, ischial tuberosity, and greater trochanter (erosions, osteophytes, calcific deposits). US is very useful for guided procedures in hip joint and periarticular soft tissues under direct visualization. The needle aspiration of synovial fluid and steroid injections are commonly-applied activities in daily rheumatology practice. The relatively limited acoustic windows available to the US beam are the principal limitations to hip US. Therefore, conducting a detailed examination of some important structures together with the interpretation of Doppler signal (sometimes undetectable) is not easy, requiring good knowledge of the modality. The aim of this review is to analyze the current literature about US of the hip and to describe the most frequently-observed normal and pathological findings.

  6. Multiple-digit resurfacing using a thin latissimus dorsi perforator flap.

    PubMed

    Kim, Sang Wha; Lee, Ho Jun; Kim, Jeong Tae; Kim, Youn Hwan

    2014-01-01

    Traumatic digit defects of high complexity and with inadequate local tissue represent challenging surgical problems. Recently, perforator flaps have been proposed for reconstructing large defects of the hand because of their thinness and pliability and minimal donor site morbidity. Here, we illustrate the use of thin latissimus dorsi perforator flaps for resurfacing multiple defects of distal digits. We describe the cases of seven patients with large defects, including digits, circumferential defects and multiple-digit defects, who underwent reconstruction with thin latissimus dorsi perforator flaps between January 2008 and March 2012. Single-digit resurfacing procedures were excluded. The mean age was 56.3 years and the mean flap size was 160.4 cm(2). All the flaps survived completely. Two patients had minor complications including partial flap loss and scar contracture. The mean follow-up period was 11.7 months. The ideal flap for digit resurfacing should be thin and amenable to moulding, have a long pedicle for microanastomosis and have minimal donor site morbidity. Thin flaps can be harvested by excluding the deep adipose layer, and their high pliability enables resurfacing without multiple debulking procedures. The latissimus dorsi perforator flap may be the best flap for reconstructing complex defects of the digits, such as large, multiple-digit or circumferential defects, which require complete wrapping of volar and dorsal surfaces.

  7. The significance of orbital anatomy and periocular wrinkling when performing laser skin resurfacing.

    PubMed

    Trelles, M A; Pardo, L; Benedetto, A V; García-Solana, L; Torrens, J

    2000-03-01

    Knowledge of orbital anatomy and the interaction of muscle contractions, gravitational forces and photoagingis fundamental in understanding the limitations of carbon dioxide (CO2) laser skin resurfacing when rejuvenating the skin of the periocular area. Laser resurfacing does not change the mimetic behavior of the facial muscles nor does it influence gravitational forces. When resurfacing periocular tissue, the creation of scleral show and ectropion are a potential consequence when there is an over zealous attempt at improving the sagging malar fat pad and eyelid laxity by performing an excess amount of laser passes at the lateral portion of the lower eyelid. This results in an inadvertent widening of the palpebral fissure due to the lateral pull of the Orbicularis oculi. Retrospectively, 85 patients were studied, who had undergone periorbital resurfacing with a CO2 laser using anew treatment approach. The Sharplan 40C CO2 Feather Touchlaser was programmed with a circular scanning pattern and used just for the shoulders of the wrinkles. A final laser pass was performed with the same program over the entire lower eyelid skin surface, excluding the outer lateral portion (e.g. a truncated triangle-like area),corresponding to the lateral canthus. Only a single laser pass was delivered to the lateral canthal triangle to avoid widening the lateral opening of the eyelid, which might lead to the potential complications of scleral show and ectropion. When the area of the crows' feet is to be treated, three passes on the skin of this entire lateral orbital surface are completed by moving laterally and upward toward the hairline. Patients examined on days 1, 7, 15, 30, 60, and one year after laser resurfacing showed good results. At two months after treatment, the clinical improvement was rated by the patient and physician as being "very good" in 81 of the 85 patients reviewed. These patients underwent laser resurfacing without complications. The proposed technique of

  8. [Surgical treatment of hip osteoarthritis: hpdete on hip arthroscopy].

    PubMed

    Ilizaliturri Sánchez, Víctor M; Camacho Galindo, Javier

    2007-10-01

    Arthroscopic surgery of the hip is a routine procedure in an increasing number of institutions around the world. Indications for this procedure increase as more experience is developed. Thanks to hip arthroscopy some intraarticular lesions like labral or ligamentum teres tears and cartilage lesions have been recognized. All of these have the potential to develop hip osteoarthritis. Open techniques for the treatment of femoroacetabular impingement have been transformed to arthroscopic techniques. Femoroacetabular impingement has the potential to cause hip osteoarthritis. The role of hip arthroscopy in the treatment of formally established hip osteoarthritis is limited and has better results in young patients with early degenerative changes.

  9. Precaution, governance and the failure of medical implants: the ASR((TM)) hip in the UK.

    PubMed

    Wienroth, Matthias; McCormack, Pauline; Joyce, Thomas J

    2014-01-01

    Hip implants have provided life-changing treatment, reducing pain and improving the mobility and independence of patients. Success has encouraged manufacturers to innovate and amend designs, engendering patient hopes in these devices. However, failures of medical implants do occur. The failure rate of the Articular Surface Replacement metal-on-metal hip system, implanted almost 100,000 times world-wide, has re-opened debate about appropriate and timely implant governance. As commercial interests, patient hopes, and devices' governance converge in a socio-technical crisis, we analyse the responses of relevant governance stakeholders in the United Kingdom between 2007 and 2014. We argue that there has been a systemic failure of the governance system entrusted with the safety of patients fitted with medical implants. Commercial considerations of medical implants and the status quo of medical implant governance have been given priority over patient safety despite the availability of significant failure data in an example of uncertainty about what constitutes appropriate precautionary action.

  10. Coupling of dynamics and contact mechanics of artificial hip joints in a pendulum model.

    PubMed

    Liu, H; Ellison, P J; Xu, H; Jin, Z

    2010-01-01

    To date, fully coupled dynamics and contact mechanics analysis is still limited by expensive computational cost and long computing time and has not been addressed comprehensively, particularly in the hip joint. To understand the influence of different parameters on the biomechanics of the total hip replacement (THR) and improve its design, two numerical approaches were developed and implemented in finite element models to investigate the coupling between the dynamics response and the contact mechanics for three different THR configurations, metal-on-polyethylene (MOP), metal-on-metal (MOM), and ceramic-on-ceramic (COC). The dynamic force and the contact pressure distribution at the bearing surfaces from the two methods were predicted and compared. The influences of various parameters (motion angle, load applied in the pendulum, friction coefficient, geometry, and material properties) were subsequently investigated. From the comparisons, the decoupled method, based on the rigid-body dynamics and the quasi-static elastic contact mechanics, was adequate to predict the performance of the THRs efficiently. The load had the greatest influence on the dynamics/contact mechanics among other factors.

  11. Hard-on-hard lubrication in the artificial hip under dynamic loading conditions.

    PubMed

    Sonntag, Robert; Reinders, Jörn; Rieger, Johannes S; Heitzmann, Daniel W W; Kretzer, J Philippe

    2013-01-01

    The tribological performance of an artificial hip joint has a particularly strong influence on its success. The principle causes for failure are adverse short- and long-term reactions to wear debris and high frictional torque in the case of poor lubrication that may cause loosening of the implant. Therefore, using experimental and theoretical approaches models have been developed to evaluate lubrication under standardized conditions. A steady-state numerical model has been extended with dynamic experimental data for hard-on-hard bearings used in total hip replacements to verify the tribological relevance of the ISO 14242-1 gait cycle in comparison to experimental data from the Orthoload database and instrumented gait analysis for three additional loading conditions: normal walking, climbing stairs and descending stairs. Ceramic-on-ceramic bearing partners show superior lubrication potential compared to hard-on-hard bearings that work with at least one articulating metal component. Lubrication regimes during the investigated activities are shown to strongly depend on the kinematics and loading conditions. The outcome from the ISO gait is not fully confirmed by the normal walking data and more challenging conditions show evidence of inferior lubrication. These findings may help to explain the differences between the in vitro predictions using the ISO gait cycle and the clinical outcome of some hard-on-hard bearings, e.g., using metal-on-metal.

  12. Wear performance of large-diameter differential-hardness hip bearings.

    PubMed

    Barnes, C Lowry; DeBoer, David; Corpe, R Scott; Nambu, Satya; Carroll, Michael; Timmerman, Irina

    2008-09-01

    We hypothesized that differential-hardness hard-on-hard bearings would generate less wear debris compared with like-hardness metal-on-metal (M-o-M) bearings. We conducted wear testing on 3 types of large-diameter hard hip bearings: (1) contemporary cast-on-cast ("like" hardness) M-o-M; (2) differential-hardness M-o-M; and (3) differential-hardness ceramic-on-metal. A simulated gait profile ranging from 200 to 2000 N was applied to the bearings at a frequency of 1 Hz for 5 Mc. All bearings were tested in an anatomically inverted position in 90% alpha calf serum. Both differential-hardness bearing systems produced lower run-in wear rates (90%-97%), steady-state wear rate (45%-84%), and total metal wear (68%-88%) compared with the like-hardness bearing system. The ceramic-on-metal bearings exhibited the least wear followed by differential-hardness M-o-M bearings; like-hardness M-o-M bearings exhibited the greatest amount of wear. These findings support our hypothesis that differential-hardness hip bearing systems produce less metallic wear debris than those with like hardness and may result in lower metal ion release in vivo.

  13. Epidemiology of hip fractures.

    PubMed

    Kannus, P; Parkkari, J; Sievänen, H; Heinonen, A; Vuori, I; Järvinen, M

    1996-01-01

    There were an estimated 1.66 million hip fractures world-wide in 1990. According to the epidemiologic projections, this worldwide annual number will rise to 6.26 million by the year 2050. This rise will be in great part due to the huge increase in the elderly population of the world. However, the age-specific incidence rates of hip fractures have also increased during the recent decades and in many countries this rise has not leveled off. In the districts where this increase has either showed or leveled off, the change seems to especially concern women's cervical fractures. In men, the increase has continued unabated almost everywhere. Reasons for the age-specific increase are not known: increase in the age-adjusted incidence of falls of the elderly individuals with accompanying deterioration in the age-adjusted bone quality (strength, mineral density) may partially explain the phenomenon. The growth of the elderly population will be more marked in Asia, Latin America, the Middle East, and Africa than in Europe and North America, and it is in the former regions that the greatest increments in hip fracture are projected so that these regions will account for over 70% of the 6.26 million hip fractures in the year 2050. The incidence rates of hip fractures vary considerably from population to population and race to race but increase exponentially with age in every group. Highest incidences have been described in the whites of Northern Europe (Scandinavia) and North America. In Finland, for example, the 1991 incidence of hip fractures was 1.1% for women and 0.7% for men over 70 years of age. Among elderly nursing home residents, the figures can be as high as 6.2% and 4.9%. The lifetime risk of a hip fracture is 16%-18% in white women and 5%-6% in white men. At the age of 80 years, every fifth woman and at the age of 90 years almost every second woman has suffered a hip fracture. Since populations are aging worldwide, the mean age of the hip fracture patients are

  14. Complications in Hip Arthroscopy

    PubMed Central

    Nakano, Naoki; Khanduja, Vikas

    2016-01-01

    Summary Background Recent developments in hip arthroscopic techniques and technology have made it possible in many cases to avoid open surgical dislocation for treating a variety of pathology in the hip. Although early reports suggest favourable results’ using hip arthroscopy and it has been shown to be a relatively safe procedure, complications do exist and can sometimes lead to significant morbidity. Methods This is a review article. The aim of this manuscript is to present the most frequent and/or serious complications that could occur at or following hip arthroscopy and some guidelines to avoid these complications. Conclusion Most complications of hip arthroscopy are minor or transient but serious complications can occur as well. A lot of complication e.g. acetabular labral puncture go unreported. Appropriate education and training, precise and meticulous surgical technique with correct instrumentation, the right indication in the right patient and adherence to advice from mentors and experienced colleagues are all essential factors for a successful outcome. Level of evidence: V. PMID:28066747

  15. The Hyperflexible Hip

    PubMed Central

    Weber, Alexander E.; Bedi, Asheesh; Tibor, Lisa M.; Zaltz, Ira; Larson, Christopher M.

    2015-01-01

    Context: Dance, gymnastics, figure skating, and competitive cheerleading require a high degree of hip range of motion. Athletes who participate in these sports use their hips in a mechanically complex manner. Evidence Acquisition: A search of the entire PubMed database (through December 2013) and additional searches of the reference lists of pertinent articles. Study Design: Systematic review. Level of Evidence: Level 3. Results: Whether innate or acquired, dancers and gymnasts have some hypermobility that allows their hips to be placed in potentially impinging or unstable positions required for their given activity. Such extremes of motion can result in both intra-articular and extra-articular impingement as well as compensatory osseous and muscular pathology. In addition, dancers and gymnasts are susceptible to impingement-induced instability. Dancers with innate generalized hyperlaxity are at increased risk of injury because of their activities and may require longer recovery times to return to play. Both nonoperative and operative treatments (arthroscopic and open) have an important role in returning flexibility athletes to their preoperative levels of sport and dance. Conclusion: Because of the extreme hip motion required and the compensatory soft tissue laxity in dancers and gymnasts, these athletes may develop instability, impingement, or combinations of both. This frequently occurs in the setting of subtle pathoanatomy or in patients with normal bony anatomy. With appropriate surgical indications and the correct operative technique, the treating surgeon can anticipate high levels of return to play for the gymnast and dancer with hip pain. PMID:26137181

  16. Resurfacing History of Vastitas Borealis, Mars: Early Amazonian Climate Implications

    NASA Astrophysics Data System (ADS)

    Tanaka, K. L.

    2001-12-01

    Geologic mapping of the north polar plains of Mars (>60° N.), aka Vastitas Borealis, based on Mars Orbiter Laser Altimeter (MOLA) topography, reveals new insights into resurfacing events in the polar region during the Amazonian Period. Deposits making up the Vastitas Borealis Formation (VBF) were emplaced at the end of the Hesperian Period and covered this entire region except for lavas of northernmost Alba Patera. No evidence for a Hesperian polar plateau has been found, although Planum Boreum could bury such evidence. A plains deposit, the Scandia unit, ranges from 20 to 200 m thick and overlies the VBF between Alba Patera and Olympia Planitia. This unit is apparently friable, because it is preserved only as eroded remnants forming knobs and mesas, including those of Scandia Colles. The VBF and Scandia units both appear to be deformed by radial tilting and concentric folding of Alba Patera. Another deposit, the Boreum unit, forms the base of Planum Boreum and possibly high-standing knobs and mesas south of Chasma Boreale and underlies the evenly bedded polar layered deposits. MOC images and MOLA data reveal that this unit has irregular bedding, locally steep scarps, and a dark color and is interpreted by S. Byrne and B. Murray (personal commun.) as a frozen sand sea. The unit may be up to a kilometer thick along the margins of Chasma Boreale and thins out away from there, possibly underlying the northern, southward-sloping ejecta of a 24 km crater at 79° N., 299° W. Potentially, the Scandia and Boreum units could be remnants of a single deposit. Within Chasma Boreale, the chasma unit forms a tongue-shaped plateau as much as 350 m thick. This unit could be a lower section of the Boreum unit, but a lack of relict knobs or mesas on its surface suggests that the unit embays the Boreum unit instead. South of Olympia Planitia, the Scandia unit becomes difficult to trace, and volcanic-like forms possibly related to eruption of material and subsequent collapse and

  17. Topographic and Morphologic Evidence for Flooding of Ganymede's Resurfaced Terrains by Low-Viscosity Water-Ice Lavas

    NASA Technical Reports Server (NTRS)

    McKinnon, W. B.; Schenk, P. M.; Moore, J. M.

    2001-01-01

    Topographic mapping in at least three distinct regions of Ganymede reveals that smooth terrains are flat and are topographically depressed. This and embayment relationships are consistent with volcanic resurfacing. Additional information is contained in the original extended abstract.

  18. Hip impingement: beyond femoroacetabular

    PubMed Central

    Bardakos, Nikolaos V.

    2015-01-01

    In the last 20 years, femoroacetabular impingement has been at the forefront of clinical practice as a cause of hip pain in young adults. As arthroscopic techniques for the hip continue to evolve, the possible presence of a new group of conditions creating mechanical conflict in and around the hip joint (ischiofemoral, subspine and iliopsoas impingement) has recently been elucidated whilst interest in already known ‘impingement’ syndromes (pelvic-trochanteric and pectineofoveal impingement) is now revived. This article attempts to increase awareness of these relatively uncommon clinical entities by describing their pathomorphology, contact mechanics, treatment and published results available to present. It is hoped that such knowledge will diversify therapeutic options for the clinician, thereby improving outcomes in a small but not negligible portion of patients with previously unexplained persistent symptoms. PMID:27011843

  19. What Is a Hip Replacement?

    MedlinePlus

    ... Replacement PDF Version Size: 123 KB Audio Version Time: 10:01 Size: 9.4 MB November 2014 What Is a Hip Replacement? Fast Facts: An Easy-to-Read Series of Publications for the Public Hip replacement surgery ...

  20. Hip joint replacement - series (image)

    MedlinePlus

    ... hip socket. The socket is usually made of metal. A liner that fits inside the socket. It ... usually plastic, but some surgeons use ceramic and metal. The liner allows the hip to move smoothly. ...

  1. X-Ray Exam: Hip

    MedlinePlus

    ... amount of radiation to make images of the hip joints (where the legs attach to the pelvis). During ... beam of radiation through the pelvic bones and hip joints, and an image is recorded on a computer ...

  2. Extra-articular hip endoscopy

    PubMed Central

    Verhelst, L.; Guevara, V.; De Schepper, J.; Van Melkebeek, J.; Pattyn, C.; Audenaert, E. A.

    2012-01-01

    The aim of this review is to evaluate the current available literature evidencing on peri-articular hip endoscopy (the third compartment). A comprehensive approach has been set on reports dealing with endoscopic surgery for recalcitrant trochanteric bursitis, snapping hip (or coxa-saltans; external and internal), gluteus medius and minimus tears and endoscopy (or arthroscopy) after total hip arthroplasty. This information can be used to trigger further research, innovation and education in extra-articular hip endoscopy. PMID:23610664

  3. X-Ray Exam: Hip

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip A A A What's in this ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that uses ...

  4. Developmental Dysplasia of the Hip

    MedlinePlus

    ... to 2-Year-Old Developmental Dysplasia of the Hip KidsHealth > For Parents > Developmental Dysplasia of the Hip A A A What's in this article? What ... Symptoms Diagnosis Treatment Outlook Developmental dysplasia of the hip (DDH) is a problem with the way a ...

  5. Hip Morphology Characterization

    PubMed Central

    Barrientos, Cristián; Diaz, Jorge; Brañes, Julian; Chaparro, Felipe; Barahona, Maximiliano; Salazar, Alfonso; Hinzpeter, Jaime

    2014-01-01

    Background: Femoroacetabular impingement (FAI) is the result of a mechanical conflict in the hip joint, and its diagnosis is based on clinical and radiological parameters. To our knowledge, there are no published studies describing the radiologic characteristics of FAI in Latin American populations. Purpose: To describe the radiological features associated with FAI in an asymptomatic Chilean population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We prospectively recruited asymptomatic patients with no history or symptoms of hip pathology who underwent abdomen-pelvis computed tomography (CT) for a nonorthopaedic indication. The acetabular and femoral parameters related to FAI were measured. Results: We studied 101 subjects (202 hips) with a mean age of 36.8 ± 14.4 years. The mean center-edge angle was 39.4° ± 7.2°. The crossover sign was present in 34 cases (33.7%). The mean alpha angle was 49.7° ± 8.3°. Depending on the cut points chosen for FAI-related parameters, between 39.6% and 69.3% of an asymptomatic Chilean population were found to have morphological features related to FAI. Conclusion: Our findings suggest that the proposed pathological threshold values in the literature cannot be extrapolated to a Chilean population, and this must be taken into consideration when evaluating Latin American patients with hip pain. PMID:26535273

  6. COMPLICATIONS IN HIP ARTHROSCOPY

    PubMed Central

    Contreras, Marcos Emílio Kuschnaroff; Hoffmann, Rafael Barreiros; de Araújo, Lúcio Cappelli Toledo; Dani, William Sotau; José Berral, Francisco

    2015-01-01

    Objectives: To determine the prevalence of complications in a series of consecutive cases of hip arthroscopy; to assess the progression of the sample through a learning curve; and to recognize the causes of complications in arthroscopic hip operations. Method: 150 consecutive cases that underwent hip arthroscopy between May 2004 and December 2008 were evaluated. The complications encountered were classified in three ways: organic system affected, severity and groups of 50 consecutive cases. The data were analyzed by means of descriptive statistics and Fisher's exact test. Results: We observed 15 complications in this study (10%): ten were neurological, two were osteoarticular, one was vascular-ischemic and two were cutaneous. In the classification of severity, three were classified as major, 12 as intermediate and none as minor. The incidence of complications over the course of the learning curve did not present any statistically significant difference (p = 0.16). Conclusions: Hip arthroscopy is a surgical procedure that involves low morbidity, but which presents complications in some cases. These complications are frequently neurological and transitory, and mainly occur because of joint traction. The complication rate did not decrease with progression of our sample. PMID:27022521

  7. INL HIP Plate Fabrication

    SciTech Connect

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  8. "Active" and "Passive" Lava Resurfacing Processes on Io: A Comparative Study of Loki Patera and Prometheus

    NASA Technical Reports Server (NTRS)

    Davies, A. G.; Matson, D. L.; Leone, G.; Wilson, L.; Keszthelyi, L. P.

    2004-01-01

    Studies of Galileo Near Infrared Mapping Spectrometer (NIMS) data and ground based data of volcanism at Prometheus and Loki Patera on Io reveal very different mechanisms of lava emplacement at these two volcanoes. Data analyses show that the periodic nature of Loki Patera s volcanism from 1990 to 2001 is strong evidence that Loki s resurfacing over this period resulted from the foundering of a crust on a lava lake. This process is designated passive , as there is no reliance on sub-surface processes: the foundering of the crust is inevitable. Prometheus, on the other hand, displays an episodicity in its activity which we designate active . Like Kilauea, a close analog, Prometheus s effusive volcanism is dominated by pulses of magma through the nearsurface plumbing system. Each system affords views of lava resurfacing processes through modelling.

  9. Digital reconstruction and donor site resurfacing: a two-flap technique.

    PubMed

    Kang, Qing-Lin; Chai, Yi-Ming; Chen, Weijia; Zeng, Bing-Fang

    2007-01-01

    Use of a great toe pulp flap is one of the methods to repair partial soft-tissue defect of the thumb or other digits. However, the conventional application of free skin grafts to close the donor site may bring donor-site morbidity. The authors present a two-flap technique that a reverse first dorsal metatarsal artery (FDMA) flap resurfaces the defect of the free great toe pulp flap. Six patients with soft-tissue defects of the thumbs or fingers were treated with this technique. Both the pulp and reverse flaps survived uneventfully after reconstruction of the thumbs and fingers. The reverse flap to resurface the donor site on the great toe was sensate and durable. Satisfactory appearance and function were gained in all patients. Results revealed that this technique can be accepted as an alternative method when treating soft tissue defect of the thumb or finger.

  10. Implant Optimisation for Primary Hip Replacement in Patients over 60 Years with Osteoarthritis: A Cohort Study of Clinical Outcomes and Implant Costs Using Data from England and Wales

    PubMed Central

    Jameson, Simon S.; Mason, James; Baker, Paul N.; Gregg, Paul J.; Deehan, David J.; Reed, Mike R.

    2015-01-01

    Background Hip replacement is one of the most commonly performed surgical procedures worldwide; hundreds of implant configurations provide options for femoral head size, joint surface material and fixation method with dramatically varying costs. Robust comparative evidence to inform the choice of implant is needed. This retrospective cohort study uses linked national databases from England and Wales to determine the optimal type of replacement for patients over 60 years undergoing hip replacement for osteoarthritis. Methods and Findings Implants included were the commonest brand from each of the four types of replacement (cemented, cementless, hybrid and resurfacing); the reference prosthesis was the cemented hip procedure. Patient reported outcome scores (PROMs), costs and risk of repeat (revision) surgery were examined. Multivariable analyses included analysis of covariance to assess improvement in PROMs (Oxford hip score, OHS, and EQ5D index) (9159 linked episodes) and competing risks modelling of implant survival (79,775 procedures). Cost of implants and ancillary equipment were obtained from National Health Service procurement data. Results EQ5D score improvements (at 6 months) were similar for all hip replacement types. In females, revision risk was significantly higher in cementless hip prostheses (hazard ratio, HR = 2.22, p<0.001), when compared to the reference hip. Although improvement in OHS was statistically higher (22.1 versus 20.5, p<0.001) for cementless implants, this small difference is unlikely to be clinically important. In males, revision risk was significantly higher in cementless (HR = 1.95, p = 0.003) and resurfacing implants, HR = 3.46, p<0.001), with no differences in OHS. Material costs were lowest with the reference implant (cemented, range £1103 to £1524) and highest with cementless implants (£1928 to £4285). Limitations include the design of the study, which is intrinsically vulnerable to omitted variables, a paucity of long

  11. Hip Arthroscopy in The Athlete

    PubMed Central

    2007-01-01

    Sports related injuries to the hip have received relatively little attention, in the part because the clinical assessment, imaging studies, and surgical techniques are less sophisticated. The evolution of hip arthroscopy has offered a less invasive technique that allows for recognition and treatment of hip pathologies that previously went unrecognized. The success of hip arthoscopy is dependent on proper patient selection based on the patient's history and diagnosis. The purpose of this clinical commentary is to outline mechanisms of injury and specific lesions that can be addresses using hip arthoscopy. PMID:21509141

  12. Hip Arthroscopy: A Brief History.

    PubMed

    Kandil, Abdurrahman; Safran, Marc R

    2016-07-01

    Hip arthroscopy is a fast-growing and evolving field. Like knee and shoulder arthroscopy, hip arthroscopy began as a diagnostic procedure and then progressed to biopsy and resection of abnormalities. Subsequently, it has evolved to repair of various tissues and treatment of underlying causes. As the understanding of the hip joint and its associated pathophysiology grows, indications will continue to expand for this diagnostic and therapeutic modality. This article outlines the historic developments of hip arthroscopy, including advancements in instrumentation and techniques from the days of the first hip arthroscopies to the present day.

  13. Early Attempts at Hip Arthroplasty

    PubMed Central

    Gomez, Pablo F; Morcuende, Jose A

    2005-01-01

    Over the last three centuries, treatment of hip arthritides has evolved from rudimentary surgery to modern total hip arthroplasty (THA), which is considered one of the most successful surgical interventions ever developed. We here review the history of the early hip arthroplasty procedures for hip arthritis that preceded Charley total hip arthroplasty. An evaluation of such past enterprises is relevant, and reminds us of the ephemeral nature of human industriousness, and how medical research and procedures are not isolated developments, but correlate to the social, economical, and cultural framework of their time. PMID:16089067

  14. Molecular effects of fractional carbon dioxide laser resurfacing on photodamaged human skin.

    PubMed

    Reilly, Michael J; Cohen, Marc; Hokugo, Akishige; Keller, Gregory S

    2010-01-01

    Objective To elucidate the sequential changes in protein expression that play a role in the clinically beneficial results seen with fractional carbon dioxide (CO(2)) laser resurfacing of the face and neck. Methods Nine healthy volunteers were recruited for participation from the senior author's facial plastic surgery practice. After informed consent was obtained, each volunteer underwent a 2-mm punch biopsy from a discrete area of infra-auricular neck skin prior to laser treatment. Patients then immediately underwent laser resurfacing of photodamaged face and neck skin at a minimal dose (30 W for 0.1 second) with the Pixel Perfect fractional CO(2) laser. On completion of the treatment, another biopsy specimen was taken adjacent to the first site. Additional biopsy specimens were subsequently taken from adjacent skin at 2 of 3 time points (day 7, day 14, or day 21). RNA was extracted from the specimens, and reverse transcriptase-polymerase chain reaction and protein microarray analysis were performed. Comparisons were then made between time points using pairwise comparison testing. Results We found statistically significant changes in the gene expression of several matrix metalloproteinases (MMPs). The data demonstrate a consistent up-regulation of MMPs 1, 3, 9, and 13, all of which have been previously reported for fully ablative CO(2) laser resurfacing. There was also a statistically significant increase in MMP-10 and MMP-11 levels in this data set. Conclusion This study suggests that the molecular mechanisms of action are similar for both fractional and fully ablative CO(2) laser resurfacing.

  15. The Outerbridge Classification Predicts the Need for Patellar Resurfacing in TKA

    PubMed Central

    Gómez-Cardero, Primitivo

    2009-01-01

    Patellar resurfacing (PR) in total knee arthroplasty (TKA) is controversial. The Outerbridge classification of cartilage defects in the patella is commonly used in the literature. The purpose of this study was to determine if the Outerbridge classification can predict the need for PR as part of total knee arthroplasty. Between 1995 and 2000, we performed a prospective, randomized study of 500 TKAs. We carried out PR depending on the Outerbridge classification of the patella at the time of surgery. Patients with Outerbridge Grades I, II, and III formed Group A, whereas patients with Grade IV formed Group B. Within each group, resurfacing was completed on half of the patients. Group A had 328 patients (164 with PR, 164 without PR). In Group B, there were 172 patients (86 with PR, 86 without PR). An identical prosthetic design was used for both groups. The minimum followup was 5 years (average, 7.8 years) for both Group A and Group B. At the end of followup, we assessed the number of patients in each group that required secondary resurfacing as a result of patellofemoral pain. Patients in Group A required fewer revisions for PF pain. In Group A, only one patient required a secondary PR (0.6% rate), whereas in Group B, 10 patients needed PR (11.6% rate). In Group B, the risk of need of a patellar resurfacing was 21.5 times greater than in Group A. On the basis of these findings, we recommend PR in Outerbridge Grade IV patellae, but not in Grades I, II, and III. Level of Evidence: Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. PMID:19844770

  16. Temperature, age and crust thickness distributions of Loki Patera on Io: implications for resurfacing mechanism

    NASA Technical Reports Server (NTRS)

    Davies, A. G.

    2003-01-01

    A high-spatial-resolution, multi-wavelength observation by the Galileo NIMS instrument has been analysed to determine the temperature and area distribution of a large portion of the ionian volcano Loki Patera. The temperatures of the cooler components from a two-temperature fit to the data can be used to determine ages of the surface. The age of the floor along a profile across the floor of the caldera ranges from 10 to 80 days. This puts the start of the resurfacing in July/early August 2001, yielding a resurfacing rate of approximately 1 km/day, with the new lava spreading from the SW corner of the caldera in a NE direction. This rate is consistent with resurfacing by foundering of the crust on a lava lake. However,the temperature distribution may also result from the emplacement of flows. Implied crust thicknesses (derived using a lava cooling model) range from 2.6 to 0.9 m.

  17. Resurfacing of the Martian Highlands in the Amenthes and Tyrrhena region

    SciTech Connect

    Craddock, R.A.; Maxwell, T.A. )

    1990-08-30

    The southern cratered highlands of Mars contain a large population of flat-floored, rimless craters which have previously been interpreted to have formed by aeolian mantling or flood volcanism. Neither of these geologic processes accurately explains the observed morphology or the crater statistics. Geologic mapping in the Amenthes and Tyrrhena region indicates that craters with this morphology occur on undulating intercrater materials near the dichotomy boundary and on more rugged materials farther into the highlands containing numerous ancient valley networks. Cumulative size-frequency distribution curves indicate ages of N(5) = 790 (early to middle Noachian) and N(5) = 540 (middle Noachian) for the cratered plateau and cratered highland materials, respectively, opposite the observed stratigraphic relations. For crater diameters >16 km the population of impact craters is consistent with stratigraphy, but the population of smaller craters in the region indicates the importance of resurfacing. Superposed, fresh craters indicate a resurfacing event that ceased at N(5) = 200-250 (late Noachian to early Hesperian). Crater counts divided into 5{degree} latitudinal bins show an increase in the number of craters between the 8- and 50-km-diameter range with increasing northerly latitudes, suggesting that the resurfacing was not a single event. Statistical modelling of an erosive event capable of removing the continuous ejecta deposits from the craters, eroding them to reduce the apparent diameter, and simultaneously burying smaller eroded craters explains both the morphology of the flat-floored, rimless craters, and their population distribution.

  18. Surface Ages and Resurfacing Rates of the Polar Layered Deposits on Mars

    USGS Publications Warehouse

    Herkenhoff, K. E.; Plaut, J.J.

    2000-01-01

    Interpretation of the polar stratigraphy of Mars in terms of global climate changes is complicated by the significant difference in surface ages between the north and south polar layered terrains inferred from crater statistics. We have reassessed the cratering record in both polar regions using Viking Orbiter and Mariner 9 images. No craters have been found in the north polar layered terrain, but the surface of most of the south polar layered deposits appears to have been stable for many of the orbital/axial cycles that are thought to have induced global climate changes on Mars. The inferred surface age of the south polar layered deposits (about 10 Ma) is two orders of magnitude greater than the surface age of the north polar layered deposits and residual cap (at most 100 ka). Similarly, modeled resurfacing rates are at least 20 times greater in the north than in the south. These results are consistent with the hypotheses that polar layered deposit resurfacing rates are highest in areas covered by perennial ice and that the differences in polar resurfacing rates result from the 6.4 km difference in elevation between the polar regions. Deposition on the portion of the south polar layered deposits that is not covered by the perennial ice cap may have ceased about 5 million years ago when the obliquity of Mars no longer exceeded 40??. ?? 2000 Academic Press.

  19. Mixing of components from different manufacturers in total hip arthroplasty: prevalence and comparative outcomes

    PubMed Central

    Tucker, Keith; Pickford, Martin; Newell, Claire; Howard, Peter; Hunt, Linda P; Blom, Ashley W

    2015-01-01

    Background and purpose — There have recently been highly publicized examples of suboptimal outcomes with some newer implant designs used for total hip replacement. This has led to calls for tighter regulation. However, surgeons do not always adhere to the regulations already in place and often use implants from different manufacturers together to replace a hip, which is against the recommendations of the Medicines and Healthcare Products Regulatory Agency (MHRA) and the directions of the manufacturers. Patients and methods — We used data from the National Joint Registry of England and Wales (NJR) to investigate this practice. Results — Mixing of components was common, and we identified over 90,000 cases recorded between 2003 and 2013. In the majority of these cases (48,156), stems and heads from one manufacturer were mixed with polyethylene cemented cups from another manufacturer. When using a cemented stem and a polyethylene cup, mixing of stems from one manufacturer with cups from another was associated with a lower revision rate. At 8 years, the cumulative percentage of revisions was 1.9% (95% CI: 1.7–2.1) in the mixed group as compared to 2.4% (2.3–2.5) in the matched group (p = 0.001). Mixing of heads from one manufacturer with stems from another was associated with a higher revision rate (p < 0.001). In hip replacements with ceramic-on-ceramic or metal-on-metal bearings, mixing of stems, heads, and cups from different manufacturers was associated with similar revision rates (p > 0.05). Interpretation — Mixing of components from different manufacturers is a common practice, despite the fact that it goes against regulatory guidance. However, it is not associated with increased revision rates unless heads and stems from different manufacturers are used together. PMID:26201845

  20. State of the art in hard-on-hard bearings: how did we get here and what have we achieved?

    PubMed

    Zywiel, Michael G; Sayeed, Siraj A; Johnson, Aaron J; Schmalzried, Thomas P; Mont, Michael A

    2011-03-01

    Total hip arthroplasty has shown excellent results in decreasing pain and improving function in patients with degenerative disease of the hip. Improvements in prosthetic materials, designs and implant fixation have now resulted in wear of the bearing surface being the limitation of this technology, and a number of hard-on-hard couples have been introduced to address this concern. The purpose of this article is to review the origins, development, survival rates and potential advantages and disadvantages of the following hard-on-hard bearings for total hip arthroplasty: metal-on-metal standard total hip arthroplasty; metal-on-metal hip resurfacing arthroplasty, ceramic-on-ceramic total hip arthroplasty; and ceramic-on-metal bearings. Improvements in the manufacturing of metal-on-metal bearings over the past 50 years have resulted in implants that provide low wear rates and allow for the use of large femoral heads. However, concerns remain regarding elevated serum metal ion levels, potential teratogenic effects and potentially devastating adverse local tissue reactions, whose incidence and pathogenesis remains unclear. Modern total hip resurfacing has shown excellent outcomes over 10 years in the hands of experienced surgeons. Current ceramic-on-ceramic bearings have demonstrated excellent survival with exceptionally low wear rates and virtually no local adverse effects. Concerns remain for insertional chipping, in vivo fracture and the variable incidence of squeaking. Contemporary ceramic-on-metal interfaces are in the early stages of clinical use, with little data reported to date. Hard-on-hard bearings for total hip arthroplasty have improved dramatically over the past 50 years. As bearing designs continue to improve with new and modified materials and improved manufacturing techniques, it is likely that the use of hard-on-hard bearings will continue to increase, especially in young and active patients.

  1. Conus hip prosthesis.

    PubMed

    Wagner, H; Wagner, M

    2001-01-01

    50 years ago, prosthetic replacement of the hip joint ushered in a new epoch in orthopaedics. Total hip replacement made it possible to remove a severely diseased, painful hip and restore normal function and a normal quality of life to the afflicted patient. The early results of total hip replacement are almost all spectacular and hip replacement has become the most successful type of orthopaedic surgery. These good results using an approach that was technically relatively simple resulted in a temptation to implant prosthetic hip joints with ever increasing frequency in ever younger patients. This led to the emergence of new problems, which were not so clearly recognised at the outset: it emerged that the stability of prosthetic hip joints was of limited duration. This had the following consequence: If a total hip prosthesis is implanted in an elderly person whose remaining life-expectancy is shorter than the longevity of the prosthesis, hip replacement is a life-long solution. We can therefore say that, for a patient who has only 10 to 15 years left to live, their hip problem is solved by total hip replacement. For young people, who still have a long life expectancy in front of them, it is different. They will experience failure of the artificial joint and require further surgery. The commonest and most important type of failure in total hip prostheses is aseptic loosening, which is associated with resorption of bone at the site of the prosthesis. The cause of this phenomenon has only gradually been recognised in the course of the years. Initially, the unanimous opinion was that the methacrylate cement, used to fix the components of the prosthesis in the bone, was the definitive cause of aseptic loosening because fissures and fractures of the cement were almost always found during surgical revision of loosened joints. There was talk of "cement disease" and great efforts were made to improve the quality of the cement and the cementing technique. Moreover, even

  2. Total hip replacement in young adults with hip dysplasia

    PubMed Central

    2011-01-01

    Background and purpose Dysplasia of the hip increases the risk of secondary degenerative change and subsequent total hip replacement. Here we report on age at diagnosis of dysplasia, previous treatment, and quality of life for patients born after 1967 and registered with a total hip replacement due to dysplasia in the Norwegian Arthroplasty Register. We also used the medical records to validate the diagnosis reported by the orthopedic surgeon to the register. Methods Subjects born after January 1, 1967 and registered with a primary total hip replacement in the Norwegian Arthroplasty Register during the period 1987–2007 (n = 713) were included in the study. Data on hip symptoms and quality of life (EQ-5D) were collected through questionnaires. Elaborating information was retrieved from the medical records. Results 540 of 713 patients (76%) (corresponding to 634 hips) returned the questionnaires and consented for additional information to be retrieved from their medical records. Hip dysplasia accounted for 163 of 634 hip replacements (26%), 134 of which were in females (82%). Median age at time of diagnosis was 7.8 (0–39) years: 4.4 years for females and 22 years for males. After reviewing accessible medical records, the diagnosis of hip dysplasia was confirmed in 132 of 150 hips (88%). Interpretation One quarter of hip replacements performed in patients aged 40 or younger were due to an underlying hip dysplasia, which, in most cases, was diagnosed during late childhood. The dysplasia diagnosis reported to the register was correct for 88% of the hips. PMID:21434808

  3. Is the hip capsule thicker in diseased hips?

    PubMed Central

    Bonura, A. A.; Nairn, R.; Schweitzer, M. E.; Kolanko, N. M.; Beaule, P. E.

    2016-01-01

    Objectives The purpose of this study was to compare the thickness of the hip capsule in patients with surgical hip disease, either with cam-femoroacetabular impingement (FAI) or non-FAI hip pathology, with that of asymptomatic control hips. Methods A total of 56 hips in 55 patients underwent a 3Tesla MRI of the hip. These included 40 patients with 41 hips with arthroscopically proven hip disease (16 with cam-FAI; nine men, seven women; mean age 39 years, 22 to 58) and 25 with non-FAI chondrolabral pathology (four men, 21 women; mean age 40 years, 18 to 63) as well as 15 asymptomatic volunteers, whose hips served as controls (ten men, five women; mean age 62 years, 33 to 77). The maximal capsule thickness was measured anteriorly and superiorly, and compared within and between the three groups with a gender subanalysis using student’s t-test. The correlation between alpha angle and capsule thickness was determined using Pearson’s correlation coefficient. Results Superiorly, the hip capsule was significantly greater in cam- (p = 0.028) and non-FAI (p = 0.048) surgical groups compared with the asymptomatic group. Within groups, the superior capsule thickness was significantly greater than the anterior in cam- (p < 0.001) and non-FAI (p < 0.001) surgical groups, but not in the control group. There was no significant correlation between the alpha angle and capsule thickness. There were no gender differences identified in the thickness of the hip capsule. Conclusion The thickness of the capsule does not differ between cam- and non-FAI diseased hips, and thus may not be specific for a particular aetiology of hip disease. The capsule is, however, thicker in diseased surgical hips compared with asymptomatic control hips. Cite this article: K. S. Rakhra, A. A. Bonura, R. Nairn, M. E. Schweitzer, N. M. Kolanko, P. E. Beaule. Is the hip capsule thicker in diseased hips? Bone Joint Res 2016;5:586–593. DOI: 10.1302/2046-3758.511.2000495. PMID:27903506

  4. Clinical Results and Serum Metal Ion Concentrations following Ceramic-on-Metal Total Hip Arthroplasty at a Mean Follow-Up of 60 Months

    PubMed Central

    Maurer-Ertl, W.; Pranckh-Matzke, D.; Bratschitsch, G.; Maier, M.

    2017-01-01

    Background. Increased metal ion levels following total hip arthroplasty (THA) with metal-on-metal bearings are a highly debated topic. Local soft tissue reactions with chronic pain and systemic side effects such as neuropathy are described. The aim of the current study was to determine the serum metal ion concentrations of Cobalt (Co) and Chrome (Cr) after THA with a ceramic-on-metal (CoM) bearing. Patients and Methods. Between 2008 and 2010, 20 patients underwent THA using a CoM bearing. Clinical function was evaluated by standardized scores systems (Harris Hip Score and WOMAC Score) and radiological examination included X-rays. Patient's blood samples were obtained for metal ion analysis and correlation analysis was done between these results and implant position. Results. Overall, 13 patients with 14 CoM devices were available for the current series. The mean age at time of surgery was 61 years (range, 41 to 85). The postoperative follow-up ranged from 49 to 68 months (mean, 58). Metal ion determination showed mean concentrations of 3,1 µg/L (range, 0,3–15,2 µg/L) for Co and 1,6 µg/L (range, 0,1–5,5 µg/L) for Cr, respectively. A correlation between cup anteversion and Co and Cr concentrations was shown. Conclusion. The current series showed increments for Co and Cr following CoM THA. However, these levels are lower compared to metal ion concentrations in patients with metal-on-metal bearings and the international accepted threshold for revision of MoM devices. We recommend routine follow-up including at least one obligatory evaluation of serum metal ion concentrations and an MRI once to exclude local soft tissue reactions. PMID:28373980

  5. Constraints on the history of open-basin lakes on Mars from the timing of volcanic resurfacing

    NASA Astrophysics Data System (ADS)

    Goudge, T. A.; Mustard, J. F.; Head, J. W.; Fassett, C. I.

    2011-12-01

    A catalogue of 30 open-basin lakes on Mars [1] have been identified as volcanically resurfaced based on distinct morphology and mineralogy. Associated morphologies include: (1) smooth floor deposits with lobate margins; (2) high crater retention, especially at small crater sizes; (3) wrinkle ridges on the smooth floor deposits; (4) embayment of basin perimeters and older, stratigraphically underlying deposits; (5) "moat" structures surrounding the edge of the basin, suggesting subsidence of the volcanic fill [2]; (6) high thermal inertia based on THEMIS nighttime IR data [3]; and (7) roughness signatures characteristic of smooth, volcanic material [4]. In addition to studying the morphology of the open-basin lakes, the mineralogies of the floor deposits have been analyzed using orbital spectroscopy data returned from the CRISM and OMEGA instruments. This analysis reveals that these resurfaced basins contain strong mafic mineral signatures isolated to their interiors when clear spectroscopic signatures are visible. An analysis of the CRISM and OMEGA spectra reveal the presence of both olivine and pyroxene, based on distinct mineral absorptions at 1 and 2 μm, in many resurfaced basins; however, olivine appears to be the dominant mafic mineral in the majority of these units. These mineral signatures provide further evidence for the volcanic resurfacing of the studied open-basin lakes. Additionally, the studied open-basin lakes lack any evidence for mineralogical and morphologic features that would be expected for lava-water interaction. This indicates that these open-basin lakes were completely devoid of surficial water at the time of volcanic resurfacing. Ages for the resurfacing events have been determined through crater size-frequency distributions and indicate that the process of volcanic resurfacing occurred throughout the Hesperian and into the Amazonian, with the majority of basins being resurfaced in the earliest parts of the Hesperian, near the Noachian

  6. Heterotopic ossification after hip arthroscopy.

    PubMed

    Amar, Eyal; Sharfman, Zachary T; Rath, Ehud

    2015-12-01

    Heterotopic ossification (HO) after hip arthroscopy is the abnormal formation of mature lamellar bone within extra skeletal soft tissues. HO may lead to pain, impaired range of motion and possibly revision surgery. There has been a substantial amount of recent research on the pathophysiology, prophylaxis and treatment of HO associated with open and arthroscopic hip surgery. This article reviews the literature on the aforementioned topics with a focus on their application in hip arthroscopy.

  7. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint (hemi-hip) acetabular metal cemented... (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device intended to be implanted to replace a portion of the hip...

  8. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint (hemi-hip) acetabular metal cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3370 Hip joint (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip)...

  9. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hip joint (hemi-hip) acetabular metal cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3370 Hip joint (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip)...

  10. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hip joint (hemi-hip) acetabular metal cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3370 Hip joint (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip)...

  11. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hip joint (hemi-hip) acetabular metal cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3370 Hip joint (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip)...

  12. Effect of head contact on the rim of the cup on the offset loading and torque in hip joint replacement.

    PubMed

    Liu, Feng; Williams, Sophie; Jin, Zhongmin; Fisher, John

    2013-11-01

    Head contact on the rim of the cup causes stress concentration and consequently increased wear. The head contact on the rim of the cup may in addition cause an offset load and torque on the cup. The head-rim contact resulting from microseparation or subluxation has been investigated. An analytical model has been developed to calculate the offset loading and resultant torque on the cup as a function of the translational displacement of the head under simplified loading condition of the hip joint at heel strike during a walking cycle. The magnitude of the torque on the cup was found to increase with the increasing translational displacement, larger diameter heads, eccentric cups, and the coefficient of friction of the contact. The effects of cup inclination, cup rim radius, and cup coverage angle on the magnitude of the torque were found to be relatively small with a maximum variation in the torque magnitude being lower than 20%. This study has shown an increased torque due to the head loading on the rim of the cup, and this may contribute to the incidence of cup loosening. Particularly, metal-on-metal hip joints with larger head diameters may produce the highest offset loading torque.

  13. The case for ceramic-on-polyethylene as the preferred bearing for a young adult hip replacement.

    PubMed

    Cash, David J W; Khanduja, Vikas

    2014-01-01

    The optimum choice of bearing surfaces in total hip arthroplasty, particularly in the younger and more active patient, remains controversial. Despite several studies demonstrating good long-term results for the metal-on-polyethylene articulation, there has been a recent vogue towards the utilisation of hard-on-hard bearings for younger patients due, in part, to concerns regarding polyethylene induced osteolysis. However, well-documented complications concerning metal-on-metal bearings and the risk of fracture in ceramic-on-ceramic bearings have raised concerns regarding the principle of the hard-on-hard bearing in the active patient. With recent technological advancements in the manufacture of both polyethylene and alumina ceramics, the in vitro properties of each material with regards to strength and toughness have been significantly improved. In addition, ceramic femoral heads have consistently been shown to produce less in vivo polyethylene wear than similar sized metal heads. This paper aims to critically review the biomechanical, in vivo and clinical studies related to the use of the ceramic on polyethylene bearing, and highlights its potential use as the preferred bearing for a young adult hip replacement.

  14. Do different types of bearings and noise from total hip arthroplasty influence hip-related pain, function, and quality of life postoperatively?

    PubMed Central

    Varnum, Claus; Pedersen, Alma B; Kjærsgaard-Andersen, Per; Overgaard, Søren

    2016-01-01

    Background and purpose — Patient-reported outcome (PRO) is recognized as an important tool for evaluating the outcome and satisfaction after total hip arthroplasty (THA). We wanted to compare patient-reported outcome measure (PROM) scores from patients with ceramic-on-ceramic (CoC) THAs and those with metal-on-metal (MoM) THAs to scores from patients with metal-on-polyethylene (MoP) THAs, and to determine the influence of THA-related noise on PROM scores. Patients and methods — We conducted a nationwide cross-sectional questionnaire survey in a cohort of patients identified from the Danish Hip Arthroplasty Registry. The PROMs included were: hip dysfunction and osteoarthritis and outcome score (HOOS), EQ-5D-3L, EQ VAS, UCLA activity score, and questions about noise from the THA. The response rate was 85% and the number of responders was 3,089. Of these, 45% had CoC THAs, 17% had MoM THAs, and 38% had MoP THAs, with a mean length of follow-up of 7, 5, and 7 years, respectively. Results — Compared to MoP THAs, the mean PROM scores for CoC and MoM THAs were similar, except that CoC THAs had a lower mean score for HOOS Symptoms than did MoP THA. 27% of patients with CoC THAs, 29% with MoM THAs, and 12% with MoP THAs reported noise from their hip. For the 3 types of bearings, PROM scores from patients with a noisy THA were statistically significantly worse than those from patients with a silent MoP THA. The exception was noisy CoC and MoM THAs, which had the same mean UCLA activity score as silent MoP THAs. Interpretation — A high proportion of patients reported noise from the THA, and these patients had worse PROM scores than patients with silent MoP THAs. PMID:27615443

  15. Developmental Dislocation (Dysplasia) of the Hip (DDH)

    MedlinePlus

    ... developmental dysplasia (dislocation) of the hip (DDH), the hip joint has not formed normally. The ball is loose ... be taken to provide detailed pictures of the hip joint. Treatment When DDH is detected at birth, it ...

  16. Trochanteric osteotomy in total hip replacement for congenital hip disease.

    PubMed

    Hartofilakidis, G; Babis, G C; Georgiades, G; Kourlaba, G

    2011-05-01

    We studied the effect of trochanteric osteotomy in 192 total hip replacements in 140 patients with congenital hip disease. There was bony union in 158 hips (82%), fibrous union in 29 (15%) and nonunion in five (3%). The rate of union had a statistically significant relationship with the position of reattachment of the trochanter, which depended greatly on the pre-operative diagnosis. The pre-operative Trendelenburg gait substantially improved in all three disease types (dysplasia, low and high dislocation) and all four categories of reattachment position. A persistent Trendelenburg gait post-operatively was noticed mostly in patients with defective union (fibrous or nonunion). Acetabular and femoral loosening had a statistically significant relationship with defective union and the position of reattachment of the trochanter. These results suggest that the complications of trochanteric osteotomy in total hip replacement for patients with congenital hip disease are less important than the benefits of this surgical approach.

  17. An alternative method for facial resurfacing: supraclavicular skin prefabrication by perforator fascia flap.

    PubMed

    Hocaoğlu, Emre

    2014-01-01

    Prefabrication of supraclavicular skin provides a useful source for flaps congruent with the face skin. Among various vascular sources that have been used for this purpose, anterolateral thigh fascia seems to represent a greater value because of having a long and strong vascular pedicle and negligible donor-site morbidity. In this regard, we present a technical report on using the lateral circumflex femoral artery perforator flap harvest technique in preparing an anterolateral thigh fascia flap for the prefabrication of the supraclavicular skin. The technique proved successful in resurfacing the facial skin of a young female patient with a giant congenital melanocytic hairy nevus on the left side of her face.

  18. Impact crater densities on volcanoes and coronae on venus: implications for volcanic resurfacing.

    PubMed

    Namiki, N; Solomon, S C

    1994-08-12

    The density of impact craters on large volcanoes on Venus is half the average crater density for the planet. The crater density on some classes of coronae is not significantly different from the global average density, but coronae with extensive associated volcanic deposits have lower crater densities. These results are inconsistent with both single-age and steady-state models for global resurfacing and suggest that volcanoes and coronae with associated volcanism have been active on Venus over the last 500 million years.

  19. The use of a pyrocarbon capitate resurfacing implant in chronic wrist disorders.

    PubMed

    Marcuzzi, A; Ozben, H; Russomando, A

    2014-07-01

    The present study describes the technique and results of proximal row carpectomy with resection of the head of the capitate and replacement with a pyrocarbon capitate resurfacing implant. The major indication for surgical treatment was arthritic changes on the head of the capitate. Patients were assessed by range of motion, grip strength, pain and functional scoring, and radiographic studies. In most patients, wrist function was improved and pain relief was obtained. This surgical procedure may represent a good alternative to total and partial wrist arthrodesis.

  20. Facial resurfacing with a monoblock full-thickness skin graft after multiple malignant melanomas excision in xeroderma pigmentosum.

    PubMed

    Ozmen, Selahattin; Uygur, Safak; Eryilmaz, Tolga; Ak, Betul

    2012-09-01

    Xeroderma pigmentosum is an autosomal recessive disease, characterized by vulnerability of the skin to solar radiation. Increase in sunlight-induced cancer is a direct consequence of an increase in mutated cells of the skin of patients with xeroderma pigmentosum. There is no specific technique for facial resurfacing in patients with xeroderma pigmentosum. In this article, a patient with xeroderma pigmentosum with multiple malignant melanomas on her face and radical excision of total facial skin followed by facial resurfacing with monoblock full-thickness skin graft from the abdomen is presented.

  1. Use of 1540nm fractionated erbium:glass laser for split skin graft resurfacing: a case study.

    PubMed

    Narinesingh, S; Lewis, S; Nayak, B S

    2013-09-01

    The field of laser skin resurfacing has evolved rapidly over the past two decades from ablative lasers, to nonablative systems using near-infrared, intense-pulsed light and radio-frequency systems, and most recently fractional laser resurfacing. Although fractional thermolysis is still in its infancy, its efficacy in in the treatment of skin disorders have been clearly demonstrated. Here we present a case report on the safety and efficacy of a 1540nm erbium:glass laser in the treatment of the waffle pattern of a meshed skin graft in a 38-year-old patient with type V skin in the Caribbean.

  2. Hip-Hop Education Resources

    ERIC Educational Resources Information Center

    Hall, Marcella Runell

    2009-01-01

    Hip-hop music and culture are often cited as being public pedagogy, meaning the music itself has intrinsic educational value. Non-profit organizations and individual educators have graciously taken the lead in utilizing hip-hop to educate. As the academy continues to debate its effectiveness, teachers and community organizers are moving forward.…

  3. A Case-Control Study of Elective Hip Surgery among HIV-Infected Patients: Exposure to Systemic Glucocorticoids Significantly Increases the Risk

    PubMed Central

    Kerr, Elizabeth; Middleton, Annie; Churchill, Duncan; Walker-Bone, Karen

    2017-01-01

    Objectives This was a cross-sectional case-control study amongst a cohort of HIV-infected adults aiming to explore the prevalence of and risk factors for elective hip surgery (total hip arthroplasty and resurfacing). Methods Cases were identified from the outpatient database of HIV-infected adults attending one tertiary hospital service. For each case, 5 controls matched by age, gender and ethnicity were identified. From the case notes, information about demographic factors, HIV factors and risk factors for hip surgery due to osteoarthritis or avascular necrosis (body mass index, lipids, alcohol, comorbidities and treatment with oral glucocorticoids) were extracted. Results Amongst the cohort of 1900 HIV-infected outpatients, 13 cases (12 male) who had undergone hip surgery (0.7%) were identified, median age 47 years.11/13 (85%) were Caucasian and 7/13 were in stage 3 of HIV. Significantly more of the control subjects (46% vs. 16%, p=0.04) were in the asymptomatic stage of infection. Ever use of oral glucocorticoids was highly significantly associated with elective hip surgery (92% vs. 11%, P<0.001). Conclusions Amongst this young cohort, the prevalence of elective hip surgery was 0.7% with median age at surgery (47 years) considerably younger than that amongst the general population. Ever exposure to systemic glucocorticoids was highly significantly associated with elective hip surgery, suggesting that the principal mechanism underlying the need for surgery was avascular necrosis. There may be an increased need for elective hip surgery associated with HIV. PMID:24025108

  4. Ceramic-on-metal for total hip replacement: mixing and matching can lead to high wear.

    PubMed

    Affatato, Saverio; Spinelli, Michele; Zavalloni, Mara; Traina, Francesco; Carmignato, Simone; Toni, Aldo

    2010-04-01

    Ceramic-on-ceramic and metal-on-metal bearing surfaces are often employed for total hip replacement because of their resistance to wear. However, they have some limits: brittleness is a major concern for ceramic, and ion release is a drawback for metal. To reduce the effect of these limitations, a hybrid coupling of ceramic-on-metal has been proposed. The theoretical advantage of this new coupling might lead orthopedic surgeons to use it indiscriminately. We asked whether the wear rate of this innovative solution was comparable with that of ceramic-on-ceramic, which is considered to be the gold standard for wear resistance. In a hip simulator study, we tested the wear pattern of a hybrid ceramic-on-metal coupling supplied by the same distributor; in particular, three different configurations were tested for 5 million cycles: 36-mm ceramic-on-ceramic, 32-mm and 36-mm ceramic-on-metal. These combinations were gravimetrically and geometrically evaluated. After 5 million cycles, the volumetric loss for the metal acetabular cups (Phi 36-mm) was 20-fold greater than that of the ceramic cups of the same size (Phi 36-mm); a volumetric loss of 4.35 mm(3) and 0.26 mm(3) was observed, respectively, for ceramic-on-metal and ceramic-on-ceramic combinations. Significant statistical differences were observed between all 36-mm different combinations (P < 0.0001). The increased diameter of the 36-mm ceramic-on-metal configuration resulted in a lower volumetric loss compared with that of the 32-mm ceramic-on-metal configuration. Our findings showed an increase in wear for the proposed hybrid specimens with respect to that of the ceramic-on-ceramic ones. This confirms that even in the case of ceramic-on-metal bearings, mixing and matching could not prove effective wear behavior, not even comparable with that of the ceramic-on-ceramic gold standard.

  5. Feasibility of asymmetric flow field-flow fractionation coupled to ICP-MS for the characterization of wear metal particles and metalloproteins in biofluids from hip replacement patients.

    PubMed

    Loeschner, Katrin; Harrington, Chris F; Kearney, Jacque-Lucca; Langton, David J; Larsen, Erik H

    2015-06-01

    Hip replacements are used to improve the quality of life of people with orthopaedic conditions, but the use of metal-on-metal (MoM) arthroplasty has led to poor outcomes for some patients. These problems are related to the generation of micro- to nanosized metal wear particles containing Cr, Co or other elements, but the current analytical methods used to investigate the processes involved do not provide sufficient information to understand the size or composition of the wear particles generated in vivo. In this qualitative feasibility study, asymmetric flow field-flow fractionation (AF(4)) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was used to investigate metal protein binding and the size and composition of wear metal particles present in serum and hip aspirates from MoM hip replacement patients. A well-established HPLC anion exchange chromatography (AEC) separation system coupled to ICP-MS was used to confirm the metal-protein associations in the serum samples. Off-line single particle ICP-MS (spICP-MS) analysis was used to confirm the approximate size distribution indicated by AF(4) of the wear particles in hip aspirates. In the serum samples, AF(4) -ICP-MS suggested that Cr was associated with transferrin (Tf) and Co with albumin (Alb) and an unidentified species; AEC-ICP-MS confirmed these associations and also indicated an association of Cr with Alb. In the hip aspirate sample, AF(4)-ICP-MS suggested that Cr was associated with Alb and Tf and that Co was associated with Alb and two unidentified compounds; AEC analysis confirmed the Cr results and the association of Co with Alb and a second compound. Enzymatic digestion of the hip aspirate sample, followed by separation using AF(4) with detection by UV absorption (280 nm), multi-angle light scattering and ICP-MS, suggested that the sizes of the Cr-, Co- and Mo-containing wear particles in a hip aspirate sample were in the range 40-150 nm. Off-line spICP-MS was used to confirm these

  6. Economically and environmentally informed policy for road resurfacing: tradeoffs between costs and greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Reger, Darren; Madanat, Samer; Horvath, Arpad

    2014-10-01

    As road conditions worsen, users experience an increase in fuel consumption and vehicle wear and tear. This increases the costs incurred by the drivers, and also increases the amount of greenhouse gases (GHGs) that vehicles emit. Pavement condition can be improved through rehabilitation activities (resurfacing) to reduce the effects on users, but these activities also have significant cost and GHG emission impacts. The objective of pavement management is to minimize total societal (user and agency) costs. However, the environmental impacts associated with the cost-minimizing policy are not currently accounted for. We show that there exists a range of potentially optimal decisions, known as the Pareto frontier, in which it is not possible to decrease total emissions without increasing total costs and vice versa. This research explores these tradeoffs for a system of pavement segments. For a case study, a network was created from a subset of California’s highways using available traffic data. It was shown that the current resurfacing strategy used by the state’s transportation agency, Caltrans, does not fall on the Pareto frontier, meaning that significant savings in both total costs and total emissions can be achieved by switching to one of the optimal policies. The methods presented in this paper also allow the decision maker to evaluate the impact of other policies, such as reduced vehicle kilometers traveled or better construction standards.

  7. Random fractional ultrapulsed CO2 resurfacing of photodamaged facial skin: long-term evaluation.

    PubMed

    Tretti Clementoni, Matteo; Galimberti, Michela; Tourlaki, Athanasia; Catenacci, Maximilian; Lavagno, Rosalia; Bencini, Pier Luca

    2013-02-01

    Although numerous papers have recently been published on ablative fractional resurfacing, there is a lack of information in literature on very long-term results. The aim of this retrospective study is to evaluate the efficacy, adverse side effects, and long-term results of a random fractional ultrapulsed CO2 laser on a large population with photodamaged facial skin. Three hundred twelve patients with facial photodamaged skin were enrolled and underwent a single full-face treatment. Six aspects of photodamaged skin were recorded using a 5 point scale at 3, 6, and 24 months after the treatment. The results were compared with a non-parametric statistical test, the Wilcoxon's exact test. Three hundred one patients completed the study. All analyzed features showed a significant statistical improvement 3 months after the procedure. Three months later all features, except for pigmentations, once again showed a significant statistical improvement. Results after 24 months were similar to those assessed 18 months before. No long-term or other serious complications were observed. From the significant number of patients analyzed, long-term results demonstrate not only how fractional ultrapulsed CO2 resurfacing can achieve good results on photodamaged facial skin but also how these results can be considered stable 2 years after the procedure.

  8. Implications of the Utopia Gravity Anomaly for the Resurfacing of the Northern Plains of Mars

    NASA Technical Reports Server (NTRS)

    Banerdt, W. B.

    2004-01-01

    Whereas the surface units of the northern plain of Mars generally exhibit ages ranging from late Hesperian to Amazonian, interpretation of precise topographic measurements indicate that the age of the underlying "basement" is early Noachian, or almost as old as the southern highlands. This suggests that widespread but relatively superficial resurfacing has occurred throughout the northern plains since the end of early heavy bombardment. In this abstract I examine some of the possible implications of the subsurface structure inferred for the Utopia basin from gravity data on the nature of this resurfacing. The large, shallow, circular depression in Utopia Planitia has been identified as a huge impact basin, based on both geological evidence and detailed analysis of MOLA topography. Its diameter (approx. 3000 km) is equivalent to that of the Hellas basin, as is its inferred age (early Noachian). However, whereas Hellas is extremely deep with rough terrain and large slopes, the Utopia basin is a smooth, shallow, almost imperceptible bowl. Conversely, Utopia displays one of the largest (non-Tharsis-related) positive geoid anomalies on Mars, in contrast to a much more subdued negative anomaly over Hellas.

  9. The tribological behaviour of different clearance MOM hip joints with lubricants of physiological viscosities.

    PubMed

    Hu, X Q; Wood, R J K; Taylor, A; Tuke, M A

    2011-11-01

    Clearance is one of the most influential parameters on the tribological performance of metal-on-metal (MOM) hip joints and its selection is a subject of considerable debate. The objective of this paper is to study the lubrication behaviour of different clearances for MOM hip joints within the range of human physiological and pathological fluid viscosities. The frictional torques developed by MOM hip joints with a 50 mm diameter were measured for both virgin surfaces and during a wear simulator test. Joints were manufactured with three different diametral clearances: 20, 100, and 200 microm. The fluid used for the friction measurements which contained different ratios of 25 percent newborn calf serum and carboxymethyl cellulose (CMC) with the obtained viscosities values ranging from 0.001 to 0.71 Pa s. The obtained results indicate that the frictional torque for the 20 microm clearance joint remains high over the whole range of the viscosity values. The frictional torque of the 100 microm clearance joint was low for the very low viscosity (0.001 Pa s) lubricant, but increased with increasing viscosity value. The frictional torque of the 200 microm clearance joint was high at very low viscosity levels, however, it reduced with increasing viscosity. It is concluded that a smaller clearance level can enhance the formation of an elastohydrodynamic lubrication (EHL) film, but this is at the cost of preventing fluid recovery between the bearing surfaces during the unloaded phase of walking. Larger clearance bearings allow a better recovery of lubricant during the unloaded phase, which is necessary for higher viscosity lubricants. The selection of the clearance value should therefore consider both the formation of the EHL film and the fluid recovery as a function of the physiological viscosity in order to get an optimal tribological performance for MOM hip joints. The application of either 25 per cent bovine serum or water in existing in vitro tribological study should

  10. Total hip replacement for hip fracture: Surgical techniques and concepts.

    PubMed

    Coomber, Ross; Porteous, Matthew; Hubble, Matthew J W; Parker, Martyn J

    2016-10-01

    When treating a hip fracture with a total hip replacement (THR) the surgical technique may differ in a number of aspects in comparison to elective arthroplasty. The hip fracture patient is more likely to have poor bone stock secondary to osteoporosis, be older, have a greater number of co-morbidities, and have had limited peri-operative work-up. These factors lead to a higher risk of complications, morbidity and perioperative mortality. Consideration should be made to performing the THR in a laminar flow theatre, by a surgeon experienced in total hip arthroplasty, using an anterolateral approach, cementing the implant in place, using a large head size and with repair of the joint capsule. Combined Ortho-geriatric care is recommended with similar post-operative rehabilitation to elective THR patients but with less expectation of short length of stay and consideration for fracture prevention measures.

  11. Comment on 'The Global Resurfacing of Venus' by R. G. Strom, G.G. Schaber, and D.D. Dawson

    NASA Technical Reports Server (NTRS)

    Herrick, Robert R.; Izenberg, Noam; Phillips, Roger J.

    1995-01-01

    The distribution of impact craters on Venus has been the subject of a great deal of analysis since the return of Magellan data. Phillips el al. (1992) performed Monte Carlo two-dimensional (2-D) modeling of the areal distribution of craters, and the results of that exercise allowed a restricted, but still quite large, range of possible planetary resurfacing histories, including the possibility that the crater, were emplaced on a geologically inactive planet. However, the nonrandom distribution of embayed and deformed craters (Phillips el al., 1992), the hypsometric distribution of craters (Herrick and Phillips, 1994), the varied degradation states of craters (Izenberg et al., 1994), their nonrandom distribution with different geologic terrain types (Namiki and Solomon, 1994; Price et al, 1994), and three-dimensional resurfacing modeling (Bullock el al., 1993) all seem to argue against that particular possibility. In contrast, Strom el al. (1994) have collected a refined and more comprehensive data set of impact features, and they input these data into more sophisticated 2-D Monte Carlo modeling and statistical analyses of the areal distribution of craters, the hypsometric distribution of craters, and the number of embayed craters. They concluded that 'Venus experienced a global resurfacing event about 300 m.y. ago followed by a dramatic reduction of volcanism and tectonism. This global resurfacing event ended abruptly (less than 10 m.y.). The present crater population has accumulated since then and remains largely intact . . . only about 4%-6% of the planet has been volcanically resurfaced since the global event . . .' If these conclusions are well-founded, this work certainly represents a significant advancement in restricting tile number of plausible resurfacing histories for the planet. If Strom et al. (1994) are correct, it would also mean that all of the other aforementioned works are in error to various degrees, or at least represent overzealous

  12. Comment on 'The Global Resurfacing of Venus' by R. G. Strom, G.G. Schaber, and D.D. Dawson

    NASA Astrophysics Data System (ADS)

    Herrick, Robert R.; Izenberg, Noam; Phillips, Roger J.

    1995-11-01

    The distribution of impact craters on Venus has been the subject of a great deal of analysis since the return of Magellan data. Phillips el al. (1992) performed Monte Carlo two-dimensional (2-D) modeling of the areal distribution of craters, and the results of that exercise allowed a restricted, but still quite large, range of possible planetary resurfacing histories, including the possibility that the crater, were emplaced on a geologically inactive planet. However, the nonrandom distribution of embayed and deformed craters (Phillips el al., 1992), the hypsometric distribution of craters (Herrick and Phillips, 1994), the varied degradation states of craters (Izenberg et al., 1994), their nonrandom distribution with different geologic terrain types (Namiki and Solomon, 1994; Price et al, 1994), and three-dimensional resurfacing modeling (Bullock el al., 1993) all seem to argue against that particular possibility. In contrast, Strom el al. (1994) have collected a refined and more comprehensive data set of impact features, and they input these data into more sophisticated 2-D Monte Carlo modeling and statistical analyses of the areal distribution of craters, the hypsometric distribution of craters, and the number of embayed craters. They concluded that 'Venus experienced a global resurfacing event about 300 m.y. ago followed by a dramatic reduction of volcanism and tectonism. This global resurfacing event ended abruptly (less than 10 m.y.). The present crater population has accumulated since then and remains largely intact . . . only about 4%-6% of the planet has been volcanically resurfaced since the global event . . .' If these conclusions are well-founded, this work certainly represents a significant advancement in restricting tile number of plausible resurfacing histories for the planet. If Strom et al. (1994) are correct, it would also mean that all of the other aforementioned works are in error to various degrees, or at least represent overzealous

  13. Arthroscopic treatment of unstable total hip replacement.

    PubMed

    Cuéllar, Ricardo; Aguinaga, Iñaki; Corcuera, Irene; Ponte, Juan; Usabiaga, Jaime

    2010-06-01

    Hip arthroscopy may be useful in the diagnosis and treatment of apparently well-implanted but unstable total hip replacement prostheses. We present 2 cases of arthroscopically assisted capsular tightening in unstable total hip replacements. Both cases had significant capsular laxity. Case 2 had impingement of the lower part of the acetabulum with the lesser trochanter that caused hip dislocation. Early revision surgery can be avoided with the use of this technique in selected cases of unstable total hip replacements.

  14. Fracture After Total Hip Replacement

    MedlinePlus

    ... er Total Hip Replacement cont. • Dislocation • Limb length inequality • Poor fracture healing • Repeat fracture • Lack of in- ... Surgeons (AAOS). To learn more about your orthopaedic health, please visit orthoinfo.org. Page ( 5 ) AAOS does ...

  15. Monoarticular Hip Involvement in Pseudogout

    PubMed Central

    Kocyigit, Figen; Kuyucu, Ersin; Kocyigit, Ali

    2015-01-01

    Pseudogout is the acutest form of arthritis in the elderly. Although clinical manifestations vary widely, polyarticular involvement is typical mimicking osteoarthritis or rheumatoid arthritis. Monoarticular involvement is relatively rare and is generally provoked by another medical condition. There are reported cases of hip involvement by pseudogout in monoarticular form. However, all of the cases were presented as septic arthritis. In this report, we present a case of monoarticular hip involvement mimicking soft tissue abscess. We confirmed the pseudogout diagnosis after ultrasonographic evaluation of the involved hip joint and pathological and biochemical analysis of synovial fluid analysis. Diagnosis is important to avoid unnecessary medical and surgical treatment in cases of the bizarre involvement of hip in pseudogout. PMID:25838961

  16. An arthroscopic hip documentation form.

    PubMed

    Gokhale, Satesh; Khan, Munir; Kuiper, Jan-Herman; Richardson, James B; Davies, Jonathan P

    2008-07-01

    Hip arthroscopy is becoming increasingly popular. A simple, precise, and practical means of recording arthroscopic findings will be useful for diagnostic, research, and audit purposes. Basic principles of cartography exist to produce two-dimensional paper representations of our spherical planet. We used the same principles to produce a two-dimensional map of the acetabulum and femoral head. The resulting hip diagram shows the acetabulum as viewed from the side and the femoral head as viewed from above. The ligamentum teres is attached to the medial margin of the head. The head-neck junction and part of the femoral neck is shown at the opposite margin of the ligamentum teres. The hip documentation form is simple, precise, and accurate. We use it to record our findings at hip arthroscopy, which we have used to assist us in our practice.

  17. [Hip replacement in military personnel].

    PubMed

    Maksimov, I B; Paniushin, K A; Brizhan', L K; Buriachenko, B P; Varfolomeev, D I; Mimanchev, O V

    2014-01-01

    Hip joint diseases and injuries are common for orthopedic pathology among military personnel. Hip replacement is one of the most frequent operations. Authors evaluated hip replacement in 136 servicemen treated at the center of traumatology and orthopedics of Burdenko General Military Clinical Hospital of the Ministry of Defense of Russia in 2010-2013. On the basis of the conducted analysis the main disease groups were revealed, peculiarities of pathology among this category of patients. Authors proposed surgical doctrine for the treatment of this contingent. Effective surgical treatment, in particular, hip replacement surgery, conducted with the use of the proposed principles, as a rule, fully functionally cured patients and contributes to return them in the system that contributes to the strengthening of defensibility of the country.

  18. Association of hip pain with radiographic evidence of hip osteoarthritis: diagnostic test study

    PubMed Central

    Nevitt, Michael C; Niu, Jingbo; Clancy, Mary M; Lane, Nancy E; Link, Thomas M; Vlad, Steven; Tolstykh, Irina; Jungmann, Pia M.; Felson, David T; Guermazi, Ali

    2015-01-01

    Study question Is there concordance between hip pain and radiographic hip osteoarthritis? Methods In this diagnostic test study, pelvic radiographs were assessed for hip osteoarthritis in two cohorts: the Framingham Osteoarthritis Study (community of Framingham, Massachusetts) and the Osteoarthritis Initiative (a multicenter longitudinal cohort study of osteoarthritis in the United States). Using visual representation of the hip joint, participants reported whether they had hip pain on most days and the location of the pain: anterior, groin, lateral, buttocks, or low back. In the Framingham study, participants with hip pain were also examined for hip pain with internal rotation. The authors analysed the agreement between radiographic hip osteoarthritis and hip pain, and for those with hip pain suggestive of hip osteoarthritis they calculated the sensitivity, specificity, positive predictive value, and negative predictive value of radiographs as the diagnostic test. Study answer and limitations In the Framingham study (n=946), only 15.6% of hips in patients with frequent hip pain showed radiographic evidence of hip osteoarthritis, and 20.7% of hips with radiographic hip osteoarthritis were frequently painful. The sensitivity of radiographic hip osteoarthritis for hip pain localised to the groin was 36.7%, specificity 90.5%, positive predictive value 6.0%, and negative predictive value 98.9%. Results did not differ much for hip pain at other locations or for painful internal rotation. In the Osteoarthritis Initiative study (n=4366), only 9.1% of hips in patients with frequent pain showed radiographic hip osteoarthritis, and 23.8% of hips with radiographic hip osteoarthritis were frequently painful. The sensitivity of definite radiographic hip osteoarthritis for hip pain localised to the groin was 16.5%, specificity 94.0%, positive predictive value 7.1%, and negative predictive value 97.6%. Results also did not differ much for hip pain at other locations. What this

  19. Current possibilities for hip arthroplasty.

    PubMed

    Polesello, Giancarlo Cavalli; Pereira Guimarães, Rodrigo; Ricioli Júnior, Walter; Keiske Ono, Nelson; Kiyoshi Honda, Emerson; Cavalheiro de Queiroz, Marcelo

    2014-01-01

    Hip arthroscopy has been popularized over the last decade and, with technical advances regarding imaging diagnostics, understanding of the physiopathology or surgical techniques, several applications have been described. Both arthroscopy for intra-articular conditions and endoscopy for extra-articular procedures can be used in diagnosing or treating different conditions. This updated article has the objective of presenting the various current possibilities for hip arthroscopy.

  20. DYSPLASIA OF HIP DEVELOPMENT: UPDATE

    PubMed Central

    Guarniero, Roberto

    2015-01-01

    The term “developmental dysplasia of the hip” (DDH) includes a wide spectrum of abnormalities that affect the hip during its growth, ranging from dysplasia to joint dislocation and going through different degrees of coxofemoral subluxation. The incidence of DDH is variable, and depends on a number of factors, including geographical location. Approximately one in 1,000 newborn infants may present hip dislocation and around 10 in 1,000 present hip instability. Brazil has an incidence of five per 1,000 in terms of findings of a positive Ortolani sign, which is the early clinical sign for detecting the disorder. The risk factors for DDH include: female sex, white skin color, primiparity, young mother, breech presentation at birth, family history, oligohydramnios, newborns with greater weight and height, and deformities of the feet or spine. Hip examinations should be routine for newborns, and should be emphasized in maternity units. Among newborns and infants, the diagnosis of DDH is preeminently clinical and is made using the Ortolani and Barlow maneuvers. Conventional radiography is of limited value for confirming the diagnosis of DDH among newborns, and ultrasound of the hip is the ideal examination. The treatment of DDH is challenging, both for pediatric orthopedists and for general practitioners. The objectives of the treatment include diagnosis as early as possible, joint reduction and stabilization of the hip in a secure position. Classically, treatment options are divided according to different age groups, at the time of diagnosis. PMID:27022528

  1. Extensive risk analysis of mechanical failure for an epiphyseal hip prothesis: a combined numerical-experimental approach.

    PubMed

    Martelli, S; Taddei, F; Cristofolini, L; Gill, H S; Viceconti, M

    2011-02-01

    There has been recent renewed interest in proximal femur epiphyseal replacement as an alternative to conventional total hip replacement. In many branches of engineering, risk analysis has proved to be an efficient tool for avoiding premature failures of innovative devices. An extensive risk analysis procedure has been developed for epiphyseal hip prostheses and the predictions of this method have been compared to the known clinical outcomes of a well-established contemporary design, namely hip resurfacing devices. Clinical scenarios leading to revision (i.e. loosening, neck fracture and failure of the prosthetic component) were associated with potential failure modes (i.e. overload, fatigue, wear, fibrotic tissue differentiation and bone remodelling). Driving parameters of the corresponding failure mode were identified together with their safe thresholds. For each failure mode, a failure criterion was identified and studied under the most relevant physiological loading conditions. All failure modes were investigated with the most suitable investigation tool, either numerical or experimental. Results showed a low risk for each failure scenario either in the immediate postoperative period or in the long term. These findings are in agreement with those reported by the majority of clinical studies for correctly implanted devices. Although further work is needed to confirm the predictions of this method, it was concluded that the proposed risk analysis procedure has the potential to increase the efficacy of preclinical validation protocols for new epiphyseal replacement devices.

  2. Review on squeaking hips

    PubMed Central

    Levy, Yadin David; Munir, Selin; Donohoo, Shane; Walter, William Lindsay

    2015-01-01

    Squeaking is a well-recognized complication for hard-on-hard bearings. The nature of squeaking is not yet completely understood however it is considered a multifactorial phenomenon. Patient, implant, and surgical factors play a role in squeaking. It is believed that mechanisms damaging the fluid film lubrication in which these bearings function optimally have a critical role. Such mechanisms include edge loading, stripe wear, impingement, third body particles and ceramic fracture. The resonance of metallic parts can produce noise in the human audible range hence the implant metallurgic composition and design may play a role. Implant positioning can facilitate impingement and edge loading enhancing the occurrence of squeaking. The recent introduction of large heads (> 36 mm) 4th generation ceramic-on-ceramic bearing may accentuate the conditions facilitating noise formation; however the current literature is insufficient. Clinically, squeaking may manifest in extreme hip positions or during normal gait cycle however it is rarely associated with pain. Evaluations of patients with squeaking include clinical and radiographic assessments. Computer tomography is recommended as it can better reveal ceramic breakage and implant malposition. The treatments for most squeaking patients include reassurance and activity modification. However for some, noise can be a problem, requiring further surgical intervention. In the occurrence of ceramic fracture, implant failure, extreme components malposition, instability and impingement, surgery should be advised. This review will aim to discuss the current literature regarding squeaking. PMID:26601063

  3. Skin resurfacing in a circumferential full thickness burn to the penis: lessons learnt.

    PubMed

    Jabir, Shehab; Frew, Quentin; Thompson, Richard; Dziewulski, Peter

    2013-08-13

    A circumferential full-thickness burn to the penis is a rarely encountered injury. However, when it does occur, it proves a management challenge to the plastic and burns surgeon in terms of reconstruction. This is due to the need of not only regaining adequate function of the organ, but also because of the need for a pleasing aesthetic outcome. Split-skin grafts have been utilised successfully to resurface full thickness burns of the penis and have given good results. Yet the success of split-skin grafts, especially those applied to an anatomically challenging region of the body such as the penis, depends on a number of carefully thought-out steps. We discuss the case of a circumferential full-thickness burn to the penis which was treated with split-skin grafting and highlight important pitfalls that the plastic and burns surgeon need to be aware of to ensure a successful outcome.

  4. Skin resurfacing in a circumferential full thickness burn to the penis: lessons learnt

    PubMed Central

    Jabir, Shehab; Frew, Quentin; Thompson, Richard; Dziewulski, Peter

    2013-01-01

    A circumferential full-thickness burn to the penis is a rarely encountered injury. However, when it does occur, it proves a management challenge to the plastic and burns surgeon in terms of reconstruction. This is due to the need of not only regaining adequate function of the organ, but also because of the need for a pleasing aesthetic outcome. Split-skin grafts have been utilised successfully to resurface full thickness burns of the penis and have given good results. Yet the success of split-skin grafts, especially those applied to an anatomically challenging region of the body such as the penis, depends on a number of carefully thought-out steps. We discuss the case of a circumferential full-thickness burn to the penis which was treated with split-skin grafting and highlight important pitfalls that the plastic and burns surgeon need to be aware of to ensure a successful outcome. PMID:23946511

  5. Secondary Patellar Resurfacing after Primary Bicondylar Knee Arthroplasty did Not Meet Patients’ Expectations

    PubMed Central

    Correia, João; Sieder, Marc; Kendoff, Daniel; Citak, Mustafa; Gehrke, Thorsten; Klauser, Wolfgang; Haasper, Carl

    2012-01-01

    Secondary patella resurfacing is a controversial procedure which is applied in patients with anterior knee pain after a bicondylar knee arthroplasty (with unresurfaced patella). A group of 46 patients were submitted to this procedure and their satisfaction, range of motion and pain improvement was evaluated. 52.2% of the patients were satisfied with the procedure, with an improvement in pain (Visual Analogue Scale) of 65% and an improvement in range of motion in 56,5%, with roundabout half of the patients having no resolution to their complaints. Whilst an improvement was not achieved in all patients, as it was initially hypothesised, this procedure should be considered when a revision knee arthroplasty is performed with an unresurfaced patella. PMID:23002412

  6. Secondary Patellar Resurfacing after Primary Bicondylar Knee Arthroplasty did Not Meet Patients' Expectations.

    PubMed

    Correia, João; Sieder, Marc; Kendoff, Daniel; Citak, Mustafa; Gehrke, Thorsten; Klauser, Wolfgang; Haasper, Carl

    2012-01-01

    Secondary patella resurfacing is a controversial procedure which is applied in patients with anterior knee pain after a bicondylar knee arthroplasty (with unresurfaced patella). A group of 46 patients were submitted to this procedure and their satisfaction, range of motion and pain improvement was evaluated. 52.2% of the patients were satisfied with the procedure, with an improvement in pain (Visual Analogue Scale) of 65% and an improvement in range of motion in 56,5%, with roundabout half of the patients having no resolution to their complaints. Whilst an improvement was not achieved in all patients, as it was initially hypothesised, this procedure should be considered when a revision knee arthroplasty is performed with an unresurfaced patella.

  7. Evidence for Recent Resurfacing of the Binary Kuiper Belt Object 1997 CS29

    NASA Astrophysics Data System (ADS)

    Rabinowitz, David L.; Schaefer, B.; Schaefer, M.; Tourtellotte, S.

    2009-09-01

    At solar phase angles less than 0.1 deg, some icy bodies exhibit an extraordinary opposition surge, suddenly brightening by 50% at near zero phase. Verbiscer et al [1] observed this phenomena for the icy Galilean satellites Mimas, Enceladus, Tethys, Dione, and Rhea and suggest the surge results from the light-scattering properties of freshly resurfaced icy regoliths. Buratti et al [2] and Earle et al [3] observed a similarly sharp opposition surge on Neptune's icy satellite Triton, which is known to have active cryovolcanoes. Here we examine the solar phase curves of 9 Trans-Neptunian Objects that we have measured at phase angles smaller than 0.1 deg (Rabinowitz et al [4], Schaefer et al [5]), including previously unpublished observations 1997 CS29 and 2005 UJ438. This sample includes hot and cold classical Kuiper-Belt objects, Plutinos, Centaurs, and three binary TNOs. Of all these targets, only 1997 CS29 has a sharp surge at near zero phase, and a nearly flat phase curve at large angles. Since this target is also a binary with an unusually large and close companion [6], we suggest that both 1997 CS29 and its companion have been resurfaced by each other's impact ejecta via the mechanism proposed by Stern [7], with fresh surface material producing the opposition spike. [1] Verbiscer, A., et al. 2007, Science, 315, 815; [2] Buratti, B. et al. 2007, Workshop on Ices, Oceans, and Fire: Satellites of the Outer Solar System, Boulder Colorado; [3] Earle, D., et al. 2008, BAAS, 40, 480; [4] Rabinowitz, D. et al. 2007, AJ, 133, 26; [5] Schaefer, B., et al. 2009, AJ, 137, 129; [6] Stephens, D. & Knoll, K. 2006, AJ, 131,1142;[7] Stern, S. A. 2009, Icarus, 199, 571.

  8. Ablative fractional resurfacing for the treatment of traumatic scars and contractures.

    PubMed

    Uebelhoer, Nathan S; Ross, E Victor; Shumaker, Peter R

    2012-06-01

    After a decade of military conflict, thousands of wounded warriors have suffered debilitating and cosmetically disfiguring scars and scar contractures. Clearly, there is a need for effective scar treatment regimens to assist in the functional and cosmetic rehabilitation of these patients. Traditional treatments, including aggressive physical and occupational therapy and dedicated wound care, are essential. Adjunctive treatments with established laser technologies, such as vascular lasers and full-field ablative lasers, have had a somewhat limited role in scar contractures due to modest efficacy and/or an unacceptable side effect profile in compromised skin. Refractory scar contractures often require surgical revision, which can be effective, but is associated with additional surgical morbidity and a significant risk of recurrence. Furthermore, current scar treatment paradigms often dictate scar maturation for approximately a year to allow for spontaneous improvement before surgical intervention. Since 2009, the Dermatology Clinic at the Naval Medical Center San Diego has been treating scars and scar contractures in wounded warriors and others using ablative fractionated laser technology. Although traditionally associated with the rejuvenation of aged and photo-damaged skin, our clinical experience and a handful of early reports indicate that laser ablative fractional resurfacing demonstrates promising efficacy and an excellent side effect profile when applied to the functional and cosmetic enhancement of traumatic scars and contractures. This article discusses our clinical experience with ablative fractional resurfacing and its potential prominent role in rehabilitation from traumatic injuries, including a possible shift in scar treatment paradigms toward earlier procedural intervention. Potential benefits include the optimization of scar trajectory and higher levels of full or adapted function in a more favorable time course.

  9. Radiographically undetectable periprosthetic osteolysis with ASR implants: the implication of blood metal ions.

    PubMed

    Randelli, Filippo; Banci, Lorenzo; Favilla, Sara; Maglione, Daniela; Aliprandi, Alberto

    2013-09-01

    Patients with ASR implants (resurfacing and large-diameter (XL) metal-on-metal (MoM) total hip arthroplasty), even if asymptomatic and with a stable prosthesis, may present extremely high blood metal ion levels. We report on a consecutive series of fourteen ASR revisions, focusing on osteolysis and their radiographic correspondence and their correlation with blood metal ion levels. At revision, seven hips revealed severe periacetabular osteolysis which was radiographically undetectable in six and asymptomatic in five. Seven hips with no acetabular osteolysis had significantly lower serum Cr and Co ion concentrations (respectively 25.2, 41.1 μg/l) compared to the seven hips with severe acetabular bone loss (respectively 70.1, 147.0 μg/l). Elevated blood metal ion levels should be considered as a warning of undetectable and ongoing periprosthetic osteolysis in asymptomatic patients with ASR prosthesis.

  10. The digital global geologic map of Mars: chronostratigraphic ages, topographic and crater morphologic characteristics, and updated resurfacing history

    USGS Publications Warehouse

    Tanaka, K.L.; Robbins, S.J.; Fortezzo, C.M.; Skinner, J.A.; Hare, T.M.

    2014-01-01

    A new global geologic map of Mars has been completed in a digital, geographic information system (GIS) format using geospatially controlled altimetry and image data sets. The map reconstructs the geologic history of Mars, which includes many new findings collated in the quarter century since the previous, Viking-based global maps were published, as well as other discoveries that were made during the course of the mapping using new data sets. The technical approach enabled consistent and regulated mapping that is appropriate not only for the map's 1:20,000,000 scale but also for its widespread use by diverse audiences. Each geologic unit outcrop includes basic attributes regarding identity, location, area, crater densities, and chronostratigraphic age. In turn, units are grouped by geographic and lithologic types, which provide synoptic global views of material ages and resurfacing character for the Noachian, Hesperian, and Amazonian periods. As a consequence of more precise and better quality topographic and morphologic data and more complete crater-density dating, our statistical comparisons identify significant refinements for how Martian geologic terrains are characterized. Unit groups show trends in mean elevation and slope that relate to geographic occurrence and geologic origin. In comparison with the previous global geologic map series based on Viking data, the new mapping consists of half the number of units due to simpler, more conservative and globally based approaches to discriminating units. In particular, Noachian highland surfaces overall have high percentages of their areas now dated as an epoch older than in the Viking mapping. Minimally eroded (i.e., pristine) impact craters ≥3 km in diameter occur in greater proportion on Hesperian surfaces. This observation contrasts with a deficit of similarly sized craters on heavily cratered and otherwise degraded Noachian terrain as well as on young Amazonian surfaces. We interpret these as reflecting the

  11. The digital global geologic map of Mars: Chronostratigraphic ages, topographic and crater morphologic characteristics, and updated resurfacing history

    NASA Astrophysics Data System (ADS)

    Tanaka, K. L.; Robbins, S. J.; Fortezzo, C. M.; Skinner, J. A.; Hare, T. M.

    2014-05-01

    A new global geologic map of Mars has been completed in a digital, geographic information system (GIS) format using geospatially controlled altimetry and image data sets. The map reconstructs the geologic history of Mars, which includes many new findings collated in the quarter century since the previous, Viking-based global maps were published, as well as other discoveries that were made during the course of the mapping using new data sets. The technical approach enabled consistent and regulated mapping that is appropriate not only for the map's 1:20,000,000 scale but also for its widespread use by diverse audiences. Each geologic unit outcrop includes basic attributes regarding identity, location, area, crater densities, and chronostratigraphic age. In turn, units are grouped by geographic and lithologic types, which provide synoptic global views of material ages and resurfacing character for the Noachian, Hesperian, and Amazonian periods. As a consequence of more precise and better quality topographic and morphologic data and more complete crater-density dating, our statistical comparisons identify significant refinements for how Martian geologic terrains are characterized. Unit groups show trends in mean elevation and slope that relate to geographic occurrence and geologic origin. In comparison with the previous global geologic map series based on Viking data, the new mapping consists of half the number of units due to simpler, more conservative and globally based approaches to discriminating units. In particular, Noachian highland surfaces overall have high percentages of their areas now dated as an epoch older than in the Viking mapping. Minimally eroded (i.e., pristine) impact craters ≥3 km in diameter occur in greater proportion on Hesperian surfaces. This observation contrasts with a deficit of similarly sized craters on heavily cratered and otherwise degraded Noachian terrain as well as on young Amazonian surfaces. We interpret these as reflecting the

  12. [Surgical treatment of hip osteoarthritis: update in total hip arthroplasty].

    PubMed

    Ilizaliturri Sánchez, Víctor M; Mangino Pariente, Gerardo; Camacho Galindo, Javier

    2007-10-01

    Total hip replacement is one of the most successful procedures in orthopaedic surgery. There are two different technologies for implant fixation in total hip replacement: cemented and cementless, both can be combined, which is called Hybrid arthroplasty. Long term implant stability results in long term function. The most important factor that limits longevity of well-fixed implants is the wear of the articular surfaces. Wear of the polyethylene from the acetabulum generates particles that access the implant bone or the implant-cement-bone interface. This produces an inflammatory reaction, osteolysis and implant loosening. Polyethylene of higher resistance to wear and prosthetic articulations without polyethylene (hard on hard bearings), have been introduced to improve wear particle generation. Minimally invasive surgical techniques minimize surgical trauma to sort tissue around the hip joint, facilitating a better and more rapid recovery.

  13. Transient osteoporosis of the hip.

    PubMed

    Vernon, L F; Dooley, J C; Neidorf, D L

    1997-06-01

    Transient osteoporosis of the hip is an uncommon but probably underdiagnosed condition. There appears to be a predisposition for the condition in middle-aged males and in women in their third trimester of pregnancy. The etiology remains unclear, with theories that include vascular and neurologic disturbances. Clinical signs are usually pain in the hip area with functional disability of the affected limb. Plane film radiographs may be completely normal or show only minimal osteopenia. This report describes a 40-year-old male in whom transient osteoporosis of the hip was diagnosed. The patient's symptoms were initially interpreted as being due to sciatica; however, careful evaluation, further diagnostic work-up in the form of magnetic resonance imaging, and the clinical course of the disease ultimately led to the correct diagnosis. Resolution occurred gradually with non-steroidal anti-inflammatory drug therapy and rest. This case demonstrates the need for further evaluation of patients with hip-area pain who may have negative x-rays of the hip joint but continue to be symptomatic.

  14. Cementless Hydroxyapatite Coated Hip Prostheses

    PubMed Central

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  15. Combined fractional resurfacing (10600 nm/1540 nm): Tridimensional imaging evaluation of a new device for skin rejuvenation.

    PubMed

    Mezzana, Paolo; Valeriani, Maurizio; Valeriani, Roberto

    2016-11-01

    In this study were described the results, by tridimensional imaging evaluation, of the new "Combined Fractional Resurfacing" technique with the first fractional laser that overtakes the limits of traditional ablative, nonablative fractional resurfacing by combining CO2 ablative and GaAs nonablative lasers. These two wavelengths can work separately or in a mixed modality to give the best treatment choice to all the patients. In this study, it is demonstrated that the simultaneous combination of the CO2 wavelength (10600 nm) and GaAs wavelength (1540 nm) reduced the downtime, reduced pain during the treatment, and produced better results on fine wrinkles reduction and almost the same results on pigmentation as seen with 3D analysis by Antera (Miravex).

  16. Side Effects of CO2-(Er:YAG) Laser Resurfacing and Dermatography as a Treatment. A 15-Year Review

    NASA Astrophysics Data System (ADS)

    van der Velden, E. M.; Suyker-Hessels, J.; Drost, B.; Defrancq, J.; IJsselmuiden, O. E.; van Suylen, R. J.; Baruchin, A. M.

    2010-05-01

    Dermatography is the application of medical tattooing techniques. In the past, similar techniques were tried but none led to reproducible results. This study deals with the negative effects of CO2-(Er:YAG) laser treatment used for cosmetic facial resurfacing. These effects can be subdivided into two categories: the sequelae of poor (post-)operative techniques, and the inadequacy of postoperative treatment modalities. Dermatography has been applied to treat the adverse effects successfully.

  17. Gonococcal septic arthritis of the hip.

    PubMed

    Lee, A H; Chin, A E; Ramanujam, T; Thadhani, R I; Callegari, P E; Freundlich, B

    1991-12-01

    We describe a patient with a Neisseria gonorrhoeae monoarthritis of the hip. Treatment with intravenous ceftriaxone, oral doxycycline, and repeated fluoroscopic needle aspirations resulted in a complete recovery of function without residual deficit. Gonococcal monoarthritis of the hip is rare. Gonococcal hip infections appear to respond well to antibiotics and drainage by arthrocentesis. This differs from hip infections caused by other bacteria where joint damage is common and where the recommended initial treatment is open surgical drainage.

  18. Ultrasonography of the hip and lower extremity.

    PubMed

    Malanga, Gerard A; Dentico, Richard; Halperin, Jonathan S

    2010-08-01

    Musculoskeletal ultrasonographic evaluation of the proximal lower limb includes the evaluation of the soft tissue structures, including tendons, ligaments, or muscles, and the bony structures of this region, include the hip, pubic symphysis, and sacroiliac joints. The evaluation of the hip or proximal lower limb region can be performed in an efficient and systematic manner. Ultrasonography of the lateral hip, intra-articular hip, medial thigh, and posterior thigh are discussed in the article.

  19. Hip Squeaking after Ceramic-on-ceramic Total Hip Arthroplasty

    PubMed Central

    Wu, Guo-Liang; Zhu, Wei; Zhao, Yan; Ma, Qi; Weng, Xi-Sheng

    2016-01-01

    Objective: The present study aimed to review the characteristics and influencing factors of squeaking after ceramic-on-ceramic (CoC) total hip arthroplasty (THA) and to analyze the possible mechanisms of the audible noise. Data Sources: The data analyzed in this review were based on articles from PubMed and Web of Science. Study Selection: The articles selected for review were original articles and reviews found based on the following search terms: “total hip arthroplasty”, “ceramic-on-ceramic”, “hip squeaking”, and “hip noise.” Results: The mechanism of the squeaking remains unknown. The possible explanations included stripe wear, edge loading, a third body, fracture of the ceramic liner, and resonance of the prosthesis components. Squeaking occurrence is influenced by patient, surgical, and implant factors. Conclusions: Most studies indicated that squeaking after CoC THA was the consequence of increasing wear or impingement, caused by prosthesis design, patient characteristics, or surgical factors. However, as conflicts exist among different articles, the major reasons for the squeaking remain to be identified. PMID:27453238

  20. The use of hip arthroscopy in the management of the pediatric hip

    PubMed Central

    Roy, Dennis R.

    2016-01-01

    Arthroscopy of the pediatric hip began in 1977 with a publication by Gross. Interest was relatively slow to develop in the 1980s and 1990s. Coupled with the success of hip arthroscopy in the adult, interest heightened in applying the procedure to a variety of pediatric hip disorders, given that the alternative was an open surgical hip dislocation. The success of this initial group of pediatric hip arthroscopist’s has further expanded the application of hip arthroscopy as the primary or adjunct procedure for the management of intra-articular problems of the pediatric hip. PMID:27583144

  1. Subject-specific hip geometry and hip joint centre location affects calculated contact forces at the hip during gait.

    PubMed

    Lenaerts, G; Bartels, W; Gelaude, F; Mulier, M; Spaepen, A; Van der Perre, G; Jonkers, I

    2009-06-19

    Hip loading affects the development of hip osteoarthritis, bone remodelling and osseointegration of implants. In this study, we analyzed the effect of subject-specific modelling of hip geometry and hip joint centre (HJC) location on the quantification of hip joint moments, muscle moments and hip contact forces during gait, using musculoskeletal modelling, inverse dynamic analysis and static optimization. For 10 subjects, hip joint moments, muscle moments and hip loading in terms of magnitude and orientation were quantified using three different model types, each including a different amount of subject-specific detail: (1) a generic scaled musculoskeletal model, (2) a generic scaled musculoskeletal model with subject-specific hip geometry (femoral anteversion, neck-length and neck-shaft angle) and (3) a generic scaled musculoskeletal model with subject-specific hip geometry including HJC location. Subject-specific geometry and HJC location were derived from CT. Significant differences were found between the three model types in HJC location, hip flexion-extension moment and inclination angle of the total contact force in the frontal plane. No model agreement was found between the three model types for the calculation of contact forces in terms of magnitude and orientations, and muscle moments. Therefore, we suggest that personalized models with individualized hip joint geometry and HJC location should be used for the quantification of hip loading. For biomechanical analyses aiming to understand modified hip joint loading, and planning hip surgery in patients with osteoarthritis, the amount of subject-specific detail, related to bone geometry and joint centre location in the musculoskeletal models used, needs to be considered.

  2. Hip-Hop and the Academic Canon

    ERIC Educational Resources Information Center

    Abe, Daudi

    2009-01-01

    Over the last 30 years, the hip-hop movement has risen from the margins to become the preeminent force in US popular culture. In more recent times academics have begun to harness the power of hip-hop culture and use it as a means of infusing transformative knowledge into the mainstream academic discourse. On many college campuses, hip-hop's…

  3. Hip Replacement - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Hip Replacement (Arabic) العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) Total Hip Replacement Potpuna zamjena kuka - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Total Hip Replacement 全髋关节置换 - 简体中文 ( ...

  4. Adverse reaction to metal debris is more common in patients following MoM total hip replacement with a 36 mm femoral head than previously thought: results from a modern MoM follow-up programme.

    PubMed

    Lainiala, O; Eskelinen, A; Elo, P; Puolakka, T; Korhonen, J; Moilanen, T

    2014-12-01

    We conducted a retrospective study to assess the prevalence of adverse reactions to metal debris (ARMD) in patients operated on at our institution with metal-on-metal (MoM) total hip replacements with 36 mm heads using a Pinnacle acetabular shell. A total of 326 patients (150 males, 175 hips; 176 females, 203 hips) with a mean age of 62.7 years (28 to 85) and mean follow-up of 7.5 years (0.1 to 10.8) participating in our in-depth modern MoM follow-up programme were included in the study, which involved recording whole blood cobalt and chromium ion measurements, Oxford hip scores (OHS) and plain radiographs of the hip and targeted cross-sectional imaging. Elevated blood metal ion levels (> 5 parts per billion) were seen in 32 (16.1%) of the 199 patients who underwent unilateral replacement. At 23 months after the start of our modern MoM follow-up programme, 29 new cases of ARMD had been revealed. Hence, the nine-year survival of this cohort declined from 96% (95% CI 95 to 98) with the old surveillance routine to 86% (95% CI 82 to 90) following the new protocol. Although ARMD may not be as common in 36 mm MoM THRs as in those with larger heads, these results support the Medicines and Healthcare Products Regulatory Agency guidelines on regular reviews and further investigations, and emphasise the need for specific a follow-up programme for patients with MoM THRs.

  5. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) trunnion-bearing... Devices § 888.3380 Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis is a...

  6. 21 CFR 888.3380 - Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint femoral (hemi-hip) trunnion-bearing... Devices § 888.3380 Hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) trunnion-bearing metal/polyacetal cemented prosthesis is a...

  7. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) metal/polymer... § 888.3390 Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis is a...

  8. 21 CFR 888.3390 - Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint femoral (hemi-hip) metal/polymer... § 888.3390 Hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis is a...

  9. Hip-Hop Pop Art

    ERIC Educational Resources Information Center

    Talley, Clarence, Sr.

    2011-01-01

    Art has a way of helping students better understand and appreciate the world around them, particularly the things that are most important to them. Hip hop is one of those generational genres that capture the attention of young students like few other things do. Drawing on this genre to get students to create art is an excellent way to demonstrate…

  10. Developmental Dysplasia of the Hip

    MedlinePlus

    ... Lessons? Visit KidsHealth in the Classroom What Other Parents Are Reading Your Child's Development (Birth to 3 Years) Feeding Your 1- to 3-Month-Old Feeding Your 4- to 7-Month-Old Feeding Your 8- to 12-Month-Old Feeding Your 1- to 2-Year-Old ... > For Parents > Developmental Dysplasia of the Hip Print A A ...

  11. Comprehensive Review of Advancements in Hip Arthroscopy

    PubMed Central

    Noh, Chang-Kyun

    2017-01-01

    Hip arthroscopy is currently being leveraged in the diagnosis and treatment of a wide range of hip joint problems. In fact, great advancements in hip arthroscopy have resulted in an ever-expanding number of indications to which it is being applied. Minimally invasive hip arthroscopy allows for quicker initiation of rehabilitation and has attracted much attention as the field becomes increasingly focused on surgeries designed to preserve joints. This review aims to summarize the recent advances, applications, and impact of hip arthroscopy. PMID:28316958

  12. Psoas impingement syndrome in hip osteoarthritis.

    PubMed

    Di Lorenzo, Luigi; Jennifer, Yanow; Pappagallo, Marco

    2009-01-01

    The degenerative processes underlying osteoarthritis of the hip produce both anatomical and biomechanical changes in and around the involved joint. A good understanding of hip anatomy and the forces crossing the hip joint is essential to understand both hip pathology and current treatment techniques. Total hip arthroplasty (THA) has become a mainstay of treatment for advanced osteoarthritis of the hip. Several factors contribute to post-operative hip pain in THA patients. Iliopsoas impingement on the prosthetic cup after total hip replacement is one of the causes of pain following hip surgery, often due to an anterior overlap of the implant with respect to the acetabulum. The anatomic shape of the anterior acetabular ridge, which may be straight or curved, influences this overlap. In this paper we present a case illustrating a psoas impingement-like syndrome in a patient with severe hip osteoarthritis who has not undergone hip replacement surgery. We discuss the compensatory strategies employed by the patient to reduce pain and prevent falls, and show CT scan images depicting the underlying anatomic pathology.

  13. Techniques and Results for Open Hip Preservation

    PubMed Central

    Levy, David M.; Hellman, Michael D.; Haughom, Bryan; Stover, Michael D.; Nho, Shane J.

    2015-01-01

    While hip arthroscopy grows in popularity, there are still many circumstances under which open hip preservation is the most appropriately indicated. This article specifically reviews open hip preservation procedures for a variety of hip conditions. Femoral acetabular impingement may be corrected using an open surgical hip dislocation. Acetabular dysplasia may be corrected using a periacetabular osteotomy. Acetabular protrusio may require surgical hip dislocation with rim trimming and a possible valgus intertrochanteric osteotomy. Legg–Calve–Perthes disease produces complex deformities that may be better served with osteotomies of the proximal femur and/or acetabulum. Chronic slipped capital femoral epiphysis may also benefit from a surgical hip dislocation and/or proximal femoral osteotomy. PMID:26649292

  14. Hip Imaging in Athletes: Sports Imaging Series.

    PubMed

    Agten, Christoph A; Sutter, Reto; Buck, Florian M; Pfirrmann, Christian W A

    2016-08-01

    Hip or groin pain in athletes is common and clinical presentation is often nonspecific. Imaging is a very important diagnostic step in the work-up of athletes with hip pain. This review article provides an overview on hip biomechanics and discusses strategies for hip imaging modalities such as radiography, ultrasonography, computed tomography, and magnetic resonance (MR) imaging (MR arthrography and traction MR arthrography). The authors explain current concepts of femoroacetabular impingement and the problem of high prevalence of cam- and pincer-type morphology in asymptomatic persons. With the main focus on MR imaging, the authors present abnormalities of the hip joint and the surrounding soft tissues that can occur in athletes: intraarticular and extraarticular hip impingement syndromes, labral and cartilage disease, microinstability of the hip, myotendinous injuries, and athletic pubalgia. (©) RSNA, 2016.

  15. Imaging lesions of the lateral hip.

    PubMed

    Pan, Judong; Bredella, Miriam A

    2013-07-01

    The lateral aspect of the hip is composed of a complex array of osseous and soft tissue structures. Both common and uncommon clinical entities are encountered in the lateral hip. This article briefly introduces fundamental imaging anatomy and the functional roles of different osseous and soft tissue structures in the lateral aspect of the hip, followed by a discussion of relevant imaging findings of lateral hip pathology. Greater trochanteric pain syndrome is frequently encountered in patients with lateral hip pain and encompasses a spectrum of soft tissue abnormalities including trochanteric and subgluteal bursitis, and tendinopathy or tears of the gluteal tendons. In addition, different types of injuries to the gluteal myotendinous unit and injuries to the indirect head of the rectus femoris, proximal iliotibial band, and the lateral joint capsular ligaments can present with lateral hip pain. Some of the less common soft tissue abnormalities of the lateral hip include Morel-Lavallée lesion and meralgia paresthetica.

  16. Evidence and considerations in the application of chemical peels in skin disorders and aesthetic resurfacing.

    PubMed

    Rendon, Marta I; Berson, Diane S; Cohen, Joel L; Roberts, Wendy E; Starker, Isaac; Wang, Beatrice

    2010-07-01

    Chemical peeling is a popular, relatively inexpensive, and generally safe method for treatment of some skin disorders and to refresh and rejuvenate skin. This article focuses on chemical peels and their use in routine clinical practice. Chemical peels are classified by the depth of action into superficial, medium, and deep peels. The depth of the peel is correlated with clinical changes, with the greatest change achieved by deep peels. However, the depth is also associated with longer healing times and the potential for complications. A wide variety of peels are available, utilizing various topical agents and concentrations, including a recent salicylic acid derivative, beta-lipohydroxy acid, which has properties that may expand the clinical use of peels. Superficial peels, penetrating only the epidermis, can be used to enhance treatment for a variety of conditions, including acne, melasma, dyschromias, photodamage, and actinic keratoses. Medium-depth peels, penetrating to the papillary dermis, may be used for dyschromia, multiple solar keratoses, superficial scars, and pigmentary disorders. Deep peels, affecting reticular dermis, may be used for severe photoaging, deep wrinkles, or scars. Peels can be combined with other in-office facial resurfacing techniques to optimize outcomes and enhance patient satisfaction and allow clinicians to tailor the treatment to individual patient needs. Successful outcomes are based on a careful patient selection as well as appropriate use of specific peeling agents. Used properly, the chemical peel has the potential to fill an important therapeutic need in the dermatologist's and plastic surgeon's armamentarium.

  17. Tsunami waves extensively resurfaced the shorelines of an early Martian ocean

    NASA Astrophysics Data System (ADS)

    Rodriguez, J. Alexis P.; Fairén, Alberto G.; Tanaka, Kenneth L.; Zarroca, Mario; Linares, Rogelio; Platz, Thomas; Komatsu, Goro; Miyamoto, Hideaki; Kargel, Jeffrey S.; Yan, Jianguo; Gulick, Virginia; Higuchi, Kana; Baker, Victor R.; Glines, Natalie

    2016-05-01

    It has been proposed that ~3.4 billion years ago an ocean fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on early Mars, tsunamis played a major role in generating and resurfacing coastal terrains.

  18. Tsunami waves extensively resurfaced the shorelines of an early Martian ocean

    PubMed Central

    Rodriguez, J. Alexis P.; Fairén, Alberto G.; Tanaka, Kenneth L.; Zarroca, Mario; Linares, Rogelio; Platz, Thomas; Komatsu, Goro; Miyamoto, Hideaki; Kargel, Jeffrey S.; Yan, Jianguo; Gulick, Virginia; Higuchi, Kana; Baker, Victor R.; Glines, Natalie

    2016-01-01

    It has been proposed that ~3.4 billion years ago an ocean fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on early Mars, tsunamis played a major role in generating and resurfacing coastal terrains. PMID:27196957

  19. Immunohistochemical evaluation of the heat shock response to nonablative fractional resurfacing

    NASA Astrophysics Data System (ADS)

    Hantash, Basil M.; Bedi, Vikramaditya P.; Struck, Steven K.; Chan, Kin F.

    2010-11-01

    Despite the emergence of nonablative fractional resurfacing (NFR) as a new therapeutic modality for skin photoaging, little is known about the molecular events that underlie the heat shock response to different treatment parameters. Human subjects are treated with a scanned 1550-nm fractional laser at pulse energies spanning 6 to 40 mJ and a 140-μm spot size. The heat shock response is assessed immunohistochemically immediately through 7 days posttreatment. At the immediately posttreatment time point, we observe subepidermal clefting in most sections. The basal epidermis and dermal zones of sparing are both found to express HSP47, but not HSP72. By day 1, expression of HSP72 is detected throughout the epidermis, while that of HSP47 remains restricted to the basal layer. Both proteins are detected surrounding the dermal portion of the microscopic treatment zone (MTZ). This pattern of expression persists through day 7 post-NFR, although neither protein is found within the MTZ. Immediately posttreatment, the mean collagen denaturation zone width is 50 μm at 6 mJ, increasing to 202 μm at 40 mJ. The zone of cell death exceeds the denaturation zone by 19 to 55% over this pulse energy range. The two zones converge by day 7 posttreatment.

  20. Dust levitation as a major resurfacing process on the surface of a saturnian icy satellite, Atlas

    NASA Astrophysics Data System (ADS)

    Hirata, Naoyuki; Miyamoto, Hideaki

    2012-07-01

    A small inner satellite of Saturn, Atlas, has an enigmatic saucer-like shape explained by an accumulation of particles from A-ring of Saturn. However, its unusual smooth surface remains unexplained. Gardening through continuous particle impact events cannot be a unique explanation for the smoothness, because Prometheus does not exhibit a similar surface, though it too would have experienced a similar bombardment. Here, a detailed investigation using close-up images of Atlas reveals the surface to be (1) covered by fine particles (i.e., probably as small as several tens of micrometers); (2) mostly void of impact craters (i.e., only one has been thus far identified); and (3) continuously smooth, even between the equatorial ridge and the undulating polar region. These findings imply that some sort of crater-erasing process has been active on the surface of Atlas. From electro-static analyses, we propose that the upper-most layer of the fine particles can become electro-statically unstable and migrate as a result of dust levitation, which resulted in erasing craters on the surface of Atlas. If true, Atlas would represent the first recognized body where resurfacing is dominated by dust levitation.

  1. Partial humeral head resurfacing and Latarjet coracoid transfer for treatment of recurrent anterior glenohumeral instability.

    PubMed

    Moros, Chris; Ahmad, Christopher S

    2009-08-01

    Bone deficiencies of either the humeral head or glenoid fossa may cause recurrent shoulder instability following soft tissue stabilization procedures. The engaging Hill-Sachs lesion, a major risk factor for instability, has been identified in a majority of patients with recurrent anterior instability. Guidance for surgical management of large humeral head deficiency presents few available options, with even fewer clinical data to support any one technique. Anteroinferior glenoid deficiency has also been a well-documented source of recurrent instability. The Latarjet coracoid transfer procedure corrects the glenoid defect by restoring the architecture of the inferior rim. Although coracoid transfer addresses containment on the glenoid, a concomitant large humeral head defect is at risk for engagement on the corrected glenoid. This article describes a case of a 50-year-old man presenting with recurrent right shoulder dislocations status post-open stabilization procedure 10 years prior. Radiologic evaluation demonstrated a large Hill-Sachs lesion with adjacent chondral derangement and a nonunion bony Bankart lesion. The Arthrosurface HemiCap humeral head resurfacing prosthesis (Arthrosurface Inc, Franklin, Massachusetts) was used to address the Hill-Sachs lesion with a Latarjet coracoid transfer procedure. We were unable to identify examples in the literature of the HemiCap used in the correction of a Hill-Sachs lesion for recurrent anterior instability. The HemiCap prosthesis has the benefit of correcting the Hill-Sachs lesion and adjacent chondral defect while preserving uninvolved articular surface. The combination of surgical interventions produced a successful result.

  2. Tsunami waves extensively resurfaced the shorelines of an early Martian ocean.

    PubMed

    Rodriguez, J Alexis P; Fairén, Alberto G; Tanaka, Kenneth L; Zarroca, Mario; Linares, Rogelio; Platz, Thomas; Komatsu, Goro; Miyamoto, Hideaki; Kargel, Jeffrey S; Yan, Jianguo; Gulick, Virginia; Higuchi, Kana; Baker, Victor R; Glines, Natalie

    2016-05-19

    It has been proposed that ~3.4 billion years ago an ocean fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on early Mars, tsunamis played a major role in generating and resurfacing coastal terrains.

  3. Evidence and Considerations in the Application of Chemical Peels in Skin Disorders and Aesthetic Resurfacing

    PubMed Central

    Berson, Diane S.; Cohen, Joel L.; Roberts, Wendy E.; Starker, Isaac; Wang, Beatrice

    2010-01-01

    Chemical peeling is a popular, relatively inexpensive, and generally safe method for treatment of some skin disorders and to refresh and rejuvenate skin. This article focuses on chemical peels and their use in routine clinical practice. Chemical peels are classified by the depth of action into superficial, medium, and deep peels. The depth of the peel is correlated with clinical changes, with the greatest change achieved by deep peels. However, the depth is also associated with longer healing times and the potential for complications. A wide variety of peels are available, utilizing various topical agents and concentrations, including a recent salicylic acid derivative, β-lipohydroxy acid, which has properties that may expand the clinical use of peels. Superficial peels, penetrating only the epidermis, can be used to enhance treatment for a variety of conditions, including acne, melasma, dyschromias, photodamage, and actinic keratoses. Medium-depth peels, penetrating to the papillary dermis, may be used for dyschromia, multiple solar keratoses, superficial scars, and pigmentary disorders. Deep peels, affecting reticular dermis, may be used for severe photoaging, deep wrinkles, or scars. Peels can be combined with other in-office facial resurfacing techniques to optimize outcomes and enhance patient satisfaction and allow clinicians to tailor the treatment to individual patient needs. Successful outcomes are based on a careful patient selection as well as appropriate use of specific peeling agents. Used properly, the chemical peel has the potential to fill an important therapeutic need in the dermatologist's and plastic surgeon's armamentarium. PMID:20725555

  4. Reproduction of Hip Offset and Leg Length in Navigated Total Hip Arthroplasty: How Accurate Are We?

    PubMed

    Ellapparadja, Pregash; Mahajan, Vivek; Deakin, Angela H; Deep, Kamal

    2015-06-01

    This study assesses how accurately we can restore hip offset and leg length in navigated total hip arthroplasty (THA). 152 consecutive patients with navigated THA formed the study group. The contra-lateral hip formed control for measuring hip offset and leg length. All radiological measurements were made using Orthoview digital software. In the normal hip offset group, the mean is 75.73 (SD- 8.61). In the reconstructed hip offset group, the mean is 75.35 (SD - 7.48). 95.39% had hip offset within 6 mm of opposite side while 96.04% had leg length restored within 6 mm of contra-lateral side. Equivalence test revealed that the two groups of hip offsets were essentially the same. We conclude that computer navigation can successfully reproduce hip offset and leg length accurately.

  5. Minimally invasive dynamic hip screw for fixation of hip fractures

    PubMed Central

    Ho, Michael; Garau, Giorgio; Walley, Gayle; Oliva, Francesco; Panni, Alfredo Schiavone; Longo, Umile Giuseppe

    2008-01-01

    We compared a minimally invasive surgical technique to the conventional (open approach) surgical technique used in fixation of hip fractures with the dynamic hip screw (DHS) device. Using a case-control design (44 cases and 44 controls), we tested the null hypothesis that there is no difference between the two techniques in the following outcome measures: duration of surgery, time to mobilisation and weight bearing postoperatively, length of hospital stay, mean difference of pre- and postoperative haemoglobin levels, position of the lag screw of the DHS device in the femoral head, and the tip–apex distance. The minimally invasive DHS technique had significantly shorter duration of surgery and length of hospital stay. There was also less blood loss in the minimally invasive DHS technique. The minimally invasive DHS technique produces better outcome measures in the operating time, length of hospital stay, and blood loss compared to the conventional approach while maintaining equal fixation stability. PMID:18478227

  6. Frontal plane kinematics of the hip during running: Are they related to hip anatomy and strength?

    PubMed

    Baggaley, Michael; Noehren, Brian; Clasey, Jody L; Shapiro, Robert; Pohl, Michael B

    2015-10-01

    Excessive hip adduction has been associated with a number of lower extremity overuse running injuries. The excessive motion has been suggested to be the result of reduced strength of the hip abductor musculature. Hip anatomical alignment has been postulated to influence hip abduction (HABD) strength and thus may impact hip adduction during running. The purpose of this study was to investigate the relationship between hip anatomy, HABD strength, and frontal plane kinematics during running. Peak isometric HABD strength, 3D lower extremity kinematics during running, femoral neck-shaft angle (NSA), and pelvis width-femur length (PW-FL) ratio were recorded for 25 female subjects. Pearson correlations (p<0.05) were performed between variables. A fair relationship was observed between femoral NSA and HABD strength (r=-0.47, p=0.02) where an increased NSA was associated with reduced HABD strength. No relationship was observed between HABD strength and hip adduction during running. None of the anatomical measurements, NSA or PW-FL, were associated with hip adduction during running. Deviations in the femoral NSA have a limited ability to influence peak isometric hip abduction strength or frontal plane hip kinematics during running. Hip abduction strength does also not appear to be linked with changes in hip kinematics. These findings in healthy individuals question whether excessive hip adduction typically seen in female runners with overuse injuries is caused by deviations in hip abduction strength or anatomical structure.

  7. Subject-specific hip geometry affects predicted hip joint contact forces during gait.

    PubMed

    Lenaerts, G; De Groote, F; Demeulenaere, B; Mulier, M; Van der Perre, G; Spaepen, A; Jonkers, I

    2008-01-01

    Hip loading affects bone remodeling and implant fixation. In this study, we have analyzed the effect of subject-specific modeling of hip geometry on muscle activation patterns and hip contact forces during gait, using musculoskeletal modeling, inverse dynamic analysis and static optimization. We first used sensitivity analysis to analyze the effect of isolated changes in femoral neck-length (NL) and neck-shaft angle (NSA) on calculated muscle activations and hip contact force during the stance phase of gait. A deformable generic musculoskeletal model was adjusted incrementally to adopt a physiological range of NL and NSA. In a second similar analysis, we adjusted hip geometry to the measurements from digitized radiographs of 20 subjects with primary hip osteoarthrosis. Finally, we studied the effect of hip abductor weakness on muscle activation patterns and hip contact force. This analysis showed that differences in NL (41-74 mm) and NSA (113-140 degrees ) affect the muscle activation of the hip abductors during stance phase and hence hip contact force by up to three times body weight. In conclusion, the results from both the sensitivity and subject-specific analysis showed that at the moment of peak contact force, altered NSA has only a minor effect on the loading configuration of the hip. Increased NL, however, results in an increase of the three hip contact-force components and a reduced vertical loading. The results of these analyses are essential to understand modified hip joint loading, and for planning hip surgery for patients with osteoarthrosis.

  8. Staged total hip arthroplasty in a patient with hip dysplasia and a large pertrochanteric bone cyst.

    PubMed

    Langston, Joseph R; DeHaan, Alexander M; Huff, Thomas W

    2016-06-01

    Hip arthroplasty in young patients requires thoughtful preoperative planning. Patients with proximal femoral bone loss complicate this planning and may require a staged procedure to optimize implant insertion. We report on a case of a 26-year-old woman with secondary hip arthritis from developmental dysplasia of the hip and a large pertrochanteric bone cyst that was treated with staged total hip arthroplasty. The cyst was decompressed and filled with an osteoconductive and osteoinductive bone graft substitute called EquivaBone. One year later, the patient underwent a successful primary total hip arthroplasty. Fifteen-month follow-up after her hip replacement revealed resolution of postoperative pain and significant functional improvement.

  9. Pathogenesis of osteoporotic hip fractures.

    PubMed

    McClung, Michael R

    2003-01-01

    Osteoporosis is characterized late in the course of the disease by an increased risk of fracture, particularly in the elderly. It occurs in both sexes, affecting approximately 8 million women and 2 million men aged > or = 50 years (1). While low bone density is a predictor of fractures, it is not the only determinant of fracture risk. Other factors include advanced age, altered bone quality, a personal or family history of falls, frailty, poor eyesight, debilitating diseases, and high bone turnover. A diet with sufficient calcium and vitamin D is important to minimize bone loss and, along with regular exercise, to maintain muscle strength. Bisphosphonates have been shown to reduce the risk of hip fracture. For elderly patients, the use of hip protectors may be used as a treatment of last resort. Regardless of the age of the patient, individual patient risk factors must be considered to target appropriate treatment and prevent fracture.

  10. Internal snapping hip syndrome in dynamic ultrasonography

    PubMed Central

    Maczuch, Jarosław; Skupiński, Jarosław; Kukawska-Sysio, Karolina; Wawrzynek, Wojciech

    2016-01-01

    Snapping hip syndrome is an audible or palpable snap in a hip joint during movement which may be accompanied by pain or locking. It is typically seen in young athletes performing activities requiring repeated extreme movements of the hip. It may also follow a physical trauma, intramuscular injections or surgeries. There are two main forms of snapping hip: extra- or intra-articular. Extra-articular snapping hip is elicited by an abnormal movement of specific tendons and is divided into two forms: internal and external. The internal form of snapping hip syndrome is attributed to an abrupt movement of an iliopsoas tendon against an iliopectineal eminence. Radiograph results in patients with this form of snapping tend to be normal. Dynamic ultrasound is the gold standard diagnostic technique in both forms of extra-articular snapping hip syndrome. The objective of the following text is to describe a step-by-step dynamic ultrasonography examination in internal extra-articular snapping hip syndrome in accordance to the proposed checklist protocol. To evaluate abrupt movement of an involved tendon, the patient needs to perform specific provocation tests during the examination. With its real-time imaging capabilities, dynamic ultrasonography detects the exact mechanism of the abnormal tendon friction during hip movement in a noninvasive way. It also allows for a diagnosis of additional hip tissue changes which may be causing the pain. PMID:27679733

  11. [Arthrography in congenital hip dislocation].

    PubMed

    Sipukhin, Ia M; Bazlova, E S; Cheberiak, N V

    1992-01-01

    The paper is concerned with the results of contrast arthrography in 73 children with hip joint dysplasia, among which true dislocations prevailed (70 patients). In addition to bone alterations, arthrography revealed various soft tissue changes like hypertrophy and deformity of limbus, soft tissue interposition, separation of the articular sac with the presence of an isthmus, disintegration of articular cartilages. These findings are used to define indications for surgical intervention as well as for planning the area of operation.

  12. Measurement outcomes from hip simulators.

    PubMed

    de Villiers, Danielle; Shelton, Julia C

    2016-05-01

    Simulation of wear in total hip replacements has been recognised as an important factor in determining the likelihood of clinical success. However, accurate measurement of wear can be problematic with factors such as number and morphology of wear particles produced as well as ion release proving more important in the biological response to hip replacements than wear volume or wear rate alone. In this study, hard-on-hard (CoCr alloy, AgCrN coating) and hard-on-soft (CoCr alloy and CrN coating on vitamin E blended highly cross-linked polyethylene) bearing combinations were tested in an orbital hip simulator under standard and some adverse conditions. Gravimetric wear rates were determined for all bearings, with cobalt and where applicable, silver release determined throughout testing. Isolation of wear particles from the lubricating fluid was used to determine the influence of different bearing combinations and wear conditions on particle morphology. It was found that cobalt and silver could be measured in the lubricating fluid even when volumetric wear was not detectable. In hard-on-hard bearings, Pearson's correlation of 0.98 was established between metal release into the lubricating fluid and wear volume. In hard-on-soft bearings, coating the head did not influence the polyethylene wear rates measured under standard conditions but did influence the cobalt release; the diameter influenced both polyethylene wear and cobalt release, and the introduction of adverse testing generated smaller polyethylene particles. While hip simulators can be useful to assess the wear performance of a new material or design, measurement of other outcomes may yield greater insight into the clinical behaviour of the bearings in vivo.

  13. Total hip replacement in dancers.

    PubMed

    Buyls, Inge R A E; Rietveld, A B M Boni; Ourila, Tiia; Emerton, Mark E; Bird, H A

    2013-04-01

    A case report of a professional contemporary dancer who successfully returned to the stage after bilateral total hip replacements (THR) for osteoarthritis is presented, together with her own commentary and a retrospective cohort study of total hip replacements in dancers. In the presented cohort, there were no post-operative dislocations or infections, the original pain had been relieved, rehabilitation was objectively normal and all resumed their dance (teaching) activities. Nevertheless, they were disappointed about the prolonged rehabilitation. Due to their high demands as professional dancers, post-operative expectations were too optimistic in view of the usual quick and favourable results of THR in the older and less physically active, general population. In all dancers with unilateral osteoarthritis, the left hip was involved, which may reflect the tendency to use the left leg as standing leg and be suggestive that strenuous physical activity may lead to osteoarthritis. Better rehabilitation guidelines are needed for dancer patients undergoing THR, especially drawing their attention to realistic post-operative expectations.

  14. A Hip Implant Energy Harvester

    NASA Astrophysics Data System (ADS)

    Pancharoen, K.; Zhu, D.; Beeby, S. P.

    2014-11-01

    This paper presents a kinetic energy harvester designed to be embedded in a hip implant which aims to operate at a low frequency associated with body motion of patients. The prototype is designed based on the constrained volume available in a hip prosthesis and the challenge is to harvest energy from low frequency movements (< 1 Hz) which is an average frequency during free walking of a patient. The concept of magnetic-force-driven energy harvesting is applied to this prototype considering the hip movements during routine activities of patients. The magnetic field within the harvester was simulated using COMSOL. The simulated resonant frequency was around 30 Hz and the voltage induced in a coil was predicted to be 47.8 mV. A prototype of the energy harvester was fabricated and tested. A maximum open circuit voltage of 39.43 mV was obtained and the resonant frequency of 28 Hz was observed. Moreover, the power output of 0.96 μW was achieved with an optimum resistive load of 250Ω.

  15. Making A Noble-Metal-On-Metal-Oxide Catalyst

    NASA Technical Reports Server (NTRS)

    Miller, Irvin M.; Davis, Patricia P.; Upchurch, Billy T.

    1989-01-01

    Catalyst exhibits superior performance in oxidation of CO in CO2 lasers. Two-step process developed for preparing platinum- or palladium-on-tin-oxide catalyst for recombination of CO and O2, decomposition products that occur in high-voltage discharge region of closed-cycle CO2 laser. Process also applicable to other noble-metal/metal-oxide combinations.

  16. Metal-On-Metal Bonding and Rebonding Revisited

    SciTech Connect

    Bogicevic, A.

    1999-02-23

    Density-functional calculations for a wide variety of metals show that, contrary to the rebonding view of adsorbate bonding, addimers do not have notably longer surface bonds than adatoms, do not reside farther above the surface, and do not meet the rebonding arguments for augmented mobility. Rebonding concepts are found to have some utility in explaining addimer stability.

  17. Resurfacing glabrous skin defects in the hand: the thenar base donor site.

    PubMed

    Milner, Chris S; Thirkannad, Sunil M

    2014-06-01

    Defects of the glabrous skin surfaces of the palm and fingers result from numerous causes including larger fingertip injuries, unhealed burns, and after surgery for diverse pathologies. The qualities of glabrous skin are specifically tailored to the functional requirements of high-shear strength and robustness. Despite these unique properties, graft reconstruction of defects in the glabrous regions of the hand is frequently achieved with skin from nonglabrous donor sites such as the medial forearm. Nonglabrous skin has a poor color and texture match for such applications and is frequently associated with tender and unsightly donor scars. We describe our experiences of harvesting full-thickness grafts from the glabrous skin centered over the proximal flexion crease at the level of the metacarpophalangeal joint of the thumb. We have utilized this site to harvest skin grafts of up to 2 cm in width for the resurfacing of small-sized to medium-sized defects on the palmar surfaces of the hands and fingers in 28 patients under both traumatic and elective circumstances. The skin has an excellent type-match to the defect and is quick and easy to harvest due to its adjacent location to the defect. The donor scar matures quickly, and as it lies along the thumb base crease, it runs along one of the least used contact surfaces, thereby limiting the potential discomfort associated with FTSG harvest sites from other areas. Patient satisfaction with the procedure has been high, and it represents a useful alternative to traditional nonglabrous skin graft donor sites for small-sized to medium-sized defects.

  18. Histological evaluation of vertical laser channels from ablative fractional resurfacing: an ex vivo pig skin model.

    PubMed

    Skovbølling Haak, Christina; Illes, Monica; Paasch, Uwe; Hædersdal, Merete

    2011-07-01

    Ablative fractional resurfacing (AFR) represents a new treatment potential for various skin conditions and new laser devices are being introduced. It is important to gain information about the impact of laser settings on the dimensions of the created laser channels for obtaining a safe and efficient treatment outcome. The aim of this study was to establish a standard model to document the histological tissue damage profiles after AFR and to test a new laser device at diverse settings. Ex vivo abdominal pig skin was treated with a MedArt 620, prototype fractional carbon dioxide (CO(2)) laser (Medart, Hvidovre, Denmark) delivering single microbeams (MB) with a spot size of 165 μm. By using a constant pulse duration of 2 ms, intensities of 1-18 W, single and 2-4 stacked pulses, energies were delivered in a range from 2-144 mJ/MB. Histological evaluations included 3-4 high-quality histological measurements for each laser setting (n = 28). AFR created cone-shaped laser channels. Ablation depths varied from reaching the superficial dermis (2 mJ, median 41 μm) to approaching the subcutaneous fat (144 mJ, median 1,943 μm) and correlated to the applied energy levels in an approximate linear relation (r(2) = 0.84, p < 0.001). The dermal ablation width increased slightly within the energy range of 4-144 mJ (median 163 μm). The thickness of the coagulation zone reached a plateau around 65 μm at energies levels above 16 mJ. The calculated volumes of ablated tissue increased with increasing energies. We suggest this ex vivo pig skin model to characterize AFR laser channels histologically.

  19. Anatomically shaped tissue-engineered cartilage with tunable and inducible anticytokine delivery for biological joint resurfacing

    PubMed Central

    Moutos, Franklin T.; Glass, Katherine A.; Compton, Sarah A.; Ross, Alison K.; Gersbach, Charles A.; Estes, Bradley T.

    2016-01-01

    Biological resurfacing of entire articular surfaces represents an important but challenging strategy for treatment of cartilage degeneration that occurs in osteoarthritis. Not only does this approach require anatomically sized and functional engineered cartilage, but the inflammatory environment within an arthritic joint may also inhibit chondrogenesis and induce degradation of native and engineered cartilage. The goal of this study was to use adult stem cells to engineer anatomically shaped, functional cartilage constructs capable of tunable and inducible expression of antiinflammatory molecules, specifically IL-1 receptor antagonist (IL-1Ra). Large (22-mm-diameter) hemispherical scaffolds were fabricated from 3D woven poly(ε-caprolactone) (PCL) fibers into two different configurations and seeded with human adipose-derived stem cells (ASCs). Doxycycline (dox)-inducible lentiviral vectors containing eGFP or IL-1Ra transgenes were immobilized to the PCL to transduce ASCs upon seeding, and constructs were cultured in chondrogenic conditions for 28 d. Constructs showed biomimetic cartilage properties and uniform tissue growth while maintaining their anatomic shape throughout culture. IL-1Ra–expressing constructs produced nearly 1 µg/mL of IL-1Ra upon controlled induction with dox. Treatment with IL-1 significantly increased matrix metalloprotease activity in the conditioned media of eGFP-expressing constructs but not in IL-1Ra–expressing constructs. Our findings show that advanced textile manufacturing combined with scaffold-mediated gene delivery can be used to tissue engineer large anatomically shaped cartilage constructs that possess controlled delivery of anticytokine therapy. Importantly, these cartilage constructs have the potential to provide mechanical functionality immediately upon implantation, as they will need to replace a majority, if not the entire joint surface to restore function. PMID:27432980

  20. Dorsal foot resurfacing using free anterolateral thigh (ALT) flap in children.

    PubMed

    El-Gammal, Tarek A; El-Sayed, Amr; Kotb, Mohamed M; Saleh, Waleed Riad; Ragheb, Yasser Farouk; El-Refai, Omar; El Fahar, Mohammed Hassan Ali

    2013-05-01

    Very limited literature described the use of the free anterolateral thigh (ALT) among other flaps for pediatric lower limb reconstruction. The aim of this study is to present our experience using the free ALT flap for reconstruction of soft tissue defects over the dorsum of the foot and ankle in children. The study included 42 children aged 2.5-13 years with a mean of 6.18 years. Three children had crush injuries while the rest were victims of run over car accidents. All of the flaps were vascularized by at least two perforators; 88.23% were musculocutaneous and 11.77 were septocutaneous perforators. All flaps were raised in a subfascial plane. Initial thinning was performed in five flaps and 35% required subsequent debulking. Mean Flap surface area was 117.11 cm(2). The recipient arteries were the anterior tibial artery in 38 cases and posterior tibial artery in four cases. Venous anastomosis was performed to one vena commitant and in nine cases the long saphenous vein was additionally used. Mean ischemia time of the flap was 2 hours while total operative time averaged 6.3 hours. About 41% of donor sites were closed primarily while 59% required skin grafting. Primary flap survival rate was 92.8% (39/42 cases). Three flaps showed venous congestion. After venous reanastomosis, two flaps showed partial loss and one flap was lost completely. Post-operative hospital stay averaged 7.5 days. The free ALT flap could be as safe, reliable, and aesthetically appealing option for foot/ankle resurfacing in children after traumatic soft tissue loss.

  1. Implantation of scaffold-free engineered cartilage constructs in a rabbit model for chondral resurfacing.

    PubMed

    Brenner, Jillian M; Ventura, Nicole M; Tse, M Yat; Winterborn, Andrew; Bardana, Davide D; Pang, Stephen C; Hurtig, Mark B; Waldman, Stephen D

    2014-02-01

    Joint resurfacing techniques offer an attractive treatment for damaged or diseased cartilage, as this tissue characteristically displays a limited capacity for self-repair. While tissue-engineered cartilage constructs have shown efficacy in repairing focal cartilage defects in animal models, a substantial number of cells are required to generate sufficient quantities of tissue for the repair of larger defects. In a previous study, we developed a novel approach to generate large, scaffold-free cartilaginous constructs from a small number of donor cells (20 000 cells to generate a 3-cm(2) tissue construct). As comparable thicknesses to native cartilage could be achieved, the purpose of the present study was to assess the ability of these constructs to survive implantation as well as their potential for the repair of critical-sized chondral defects in a rabbit model. Evaluated up to 6 months post-implantation, allogenic constructs survived weight bearing without a loss of implant fixation. Implanted constructs appeared to integrate near-seamlessly with the surrounding native cartilage and also to extensively remodel with increasing time in vivo. By 6 months post-implantation, constructs appeared to adopt both a stratified (zonal) appearance and a biochemical composition similar to native articular cartilage. In addition, constructs that expressed superficial zone markers displayed higher histological scores, suggesting that transcriptional prescreening of constructs prior to implantation may serve as an approach to achieve superior and/or more consistent reparative outcomes. As the results of this initial animal study were encouraging, future studies will be directed toward the repair of chondral defects in more mechanically demanding anatomical locations.

  2. Posterior Hip Pain in an Athletic Population

    PubMed Central

    Frank, Rachel M.; Slabaugh, Mark A.; Grumet, Robert C.; Virkus, Walter W.; Bush-Joseph, Charles A.; Nho, Shane J.

    2010-01-01

    Context: Posterior hip pain is a relatively uncommon but increasingly recognized complaint in the orthopaedic community. Patient complaints and presentations are often vague or nonspecific, making diagnosis and subsequent treatment decisions difficult. The purposes of this article are to review the anatomy and pathophysiology related to posterior hip pain in the athletic patient population. Evidence Acquisition: Data were collected through a thorough review of the literature via a MEDLINE search of all relevant articles between 1980 and 2010. Results: Many patients who complain of posterior hip pain actually have pain referred from another part of the body—notably, the lumbar spine or sacroiliac joint. Treatment options for posterior hip pain are typically nonoperative; however, surgery is warranted in some cases. Conclusions: Recent advancements in the understanding of hip anatomy, pathophysiology, and treatment options have enabled physicians to better diagnosis athletic hip injuries and select patients for appropriate treatment. PMID:23015944

  3. RSA wear measurements with or without markers in total hip arthroplasty.

    PubMed

    Börlin, Niclas; Röhrl, Stephan M; Bragdon, Charles R

    2006-01-01

    Novel algorithms for radiostereometric (RSA) measurements of the femoral head and metal-backed, hemi-spherical cups of a total hip replacement are presented and evaluated on phantom images and clinical double examinations of 20 patients. The materials were analysed with classical RSA and three novel algorithms: (1) a dual-projection head algorithm using the outline of the femoral head together with markers in the cup; (2) a marker-less algorithm based on measurements of the outline of the femoral head, the cup shell and opening circle of the cup; and (3) a combination of both methods. The novel algorithms improve current, marker-based, RSA measurements, as well as allows studies without marked cups. This opens the possibility of performing wear measurements on larger group of patients, in clinical follow-ups, even retrospective studies. The novel algorithms may help to save patient data in current RSA studies lost due to insufficiently marked cups. Finally, the novel algorithms simplify the RSA procedure and allow new studies without markers, saving time, money, and reducing safety concerns. Other potential uses include migration measurements of re-surfacing heads and measuring spherical sections as implant landmarks instead of markers.

  4. [Treatment of infected total hip endoprostheses].

    PubMed

    Zilkens, K W; Forst, R; Casser, H R

    1989-07-01

    In total hip arthroplasty the most serious complication besides aseptic loosening is infection. The results observed in 42 cases of infected hip arthroplasties are presented. In contrast to early superficial infection, deep infection following total hip replacement is difficult to treat. Depending on the general condition of the patient, a well-defined, adequate treatment is required. In patients at vital risk the provocation of a permanent fistula can be recommended as an alternative method in preference to revision arthroplasty.

  5. Effects of hip posture on the frontal impact tolerance of the human hip joint.

    PubMed

    Rupp, Jonathan D; Reed, Matthew P; Jeffreys, Thomas A; Schneider, Lawrence W

    2003-10-01

    The pattern of left- and right-side hip injuries to front-seat occupants involved in offset and angled frontal crashes suggests that hip posture (i.e., the orientation of the femur relative to the pelvis) affects the fracture/dislocation tolerance of the hip joint to forces transmitted along the femur during knee-to-knee-bolster loading in frontal impacts. To investigate this hypothesis, dynamic hip tolerance tests were conducted on the left and right hips of 22 unembalmed cadavers. In these tests, the knee was dynamically loaded in the direction of the long axis of the femur and the pelvis was fixed to minimize inertial effects. Thirty-five successful hip tolerance tests were conducted. Twenty-five of these tests were performed with the hip oriented in a typical posture for a seated driver, or neutral posture, to provide a baseline measure of hip tolerance. The effects of hip posture on hip tolerance were quantified using a paired-comparison experimental design. In six pairs of tests, one side of each cadaver was tested with the hip joint oriented in the neutral posture and the contralateral hip from the same cadaver was tested with the hip joint adducted 10 degrees from the neutral posture. In four pairs of tests, the hip was tested in neutral and 30 degrees flexed postures. The average fracture tolerance of the hip in the neutral posture was 6.1-/+1.5 kN. Hip tolerance decreased by an average of 34-/+4% with 30 degrees of flexion from the neutral posture (p<0.0001) and by 18-/+8% with 10 degrees of adduction from the neutral posture (p=0.008).

  6. The necessity to restore the anatomic hip centre in congenital hip disease

    PubMed Central

    Lepetsos, Panagiotis; Anastasopoulos, Panagiotis P.; Galanakos, Spyridon P.

    2016-01-01

    Total hip replacement (THR) is the treatment of choice for the patient suffering from end-stage hip osteoarthritis. In the presence of deformities due to congenital hip disease (CHD), THR is, in most of the cases, a difficult task, since the technique of performing such an operation is demanding and the results could vary. We present our experience and preferred strategies focusing on challenges and surgical techniques associated with reconstructing the dysplastic hip. PMID:28090526

  7. Influence of hip position and gender on active hip internal and external rotation.

    PubMed

    Simoneau, G G; Hoenig, K J; Lepley, J E; Papanek, P E

    1998-09-01

    A general lack of descriptive details exists for measurements of hip rotation range of motion. This study was designed to establish the influence of gender and hip flexion position on active range of motion of the hip in external and internal rotation. Sixty (39 females and 21 males) healthy college-age (21.8 +/- 1.7 years) subjects were studied. Hip rotation of the dominant leg of each subject was measured in the prone (hip near 0 degree of flexion) and seated (hip near 90 degrees of flexion) positions using a standard goniometer. Data were analyzed using an analysis of variance model. Pearson's r statistics were used to determine the degree of association between measurements of hip rotation made seated vs. prone. A statistically significant difference (p < 0.05) was found between mean hip external rotation (ER) measured seated (36 +/- 7 degrees) and mean hip ER measured prone (45 +/- 10 degrees). Conversely, mean hip internal rotation (IR) measured seated (33 +/- 7 degrees) was not statistically different than mean hip IR measured prone (36 +/- 9 degrees). Females had statistically more active hip internal and external rotation than males (p < 0.05). A moderate degree of association existed between measurements of hip ER taken in the prone vs. seated position (r = 0.57, p < 0.05). For IR, the degree of association between the two measurement positions was slightly higher (r = 0.72, p < 0.05). Unlike the amount of active hip internal rotation which showed little difference between measurements made prone vs. seated, our data indicate that measurement position had a significant effect on the amount of active range of motion of the hip in ER. These findings are clinically significant for they stress the importance of documenting measurement position. They also stress the need for representative norms to be established for each hip position and gender.

  8. Management of hip involvement in ankylosing spondylitis.

    PubMed

    Guan, Mingqiang; Wang, Jian; Zhao, Liang; Xiao, Jun; Li, Zhihan; Shi, Zhanjun

    2013-08-01

    Ankylosing spondylitis (AS) is an inflammatory rheumatologic disease characterized by inflammation and progressive structural damage of the affected joints. Hip involvement often results in severe deformities and significant impairment on function. Although, tremendous progress has been made in conservative management for AS, effective prevention strategies for hip involvement and long-term need for total hip arthroplasty (THA) remain indefinite. When hip involvement has progressed to intractable pain and disability, THA is still the most effective treatment strategy to relieve pain and restore function. However, certain AS-specific problems regarding "preoperative preparation," "intraoperative difficulties," "perioperative pharmacological management," "postoperative physiotherapy," "operation benefits," and "operation complications" need more concern and further discussion.

  9. Hip Capsular Reconstruction Using Dermal Allograft.

    PubMed

    Chahla, Jorge; Dean, Chase S; Soares, Eduardo; Mook, William R; Philippon, Marc J

    2016-04-01

    Because hip arthroscopic procedures are increasing in number, complications related to the operation itself are starting to emerge. Whereas the capsule has been recognized as an important static stabilizer for the hip, it has not been until recently that surgeons have realized the importance of its preservation and restoration. Disruption of the capsule during arthroscopic procedures is a potential contributor to postoperative iatrogenic hip instability. In cases of a symptomatic deficient capsule, a capsular reconstruction is mandatory because instability may lead to detrimental chondral and labral changes. The purpose of this report was to describe our technique for arthroscopic hip capsular reconstruction using dermal allograft.

  10. International variation in hip replacement rates

    PubMed Central

    Merx, H; Dreinhofer, K; Schrader, P; Sturmer, T; Puhl, W; Gunther, K; Brenner, H

    2003-01-01

    Objectives: To summarise epidemiological data on the frequency of hip replacements in the countries of the developed world, especially in countries of the Organisation for Economic Cooperation and Development (OECD), and to investigate whether missing consensus criteria for the indication for total hip replacement (THR) result in different replacement rates. Methods: Country-specific hip replacement rates were collected using the available literature, different data sources of national authorities, and estimates of leading hip replacement manufacturers. Results: According to administrative and literature data sources the reported crude primary THR rate varied between 50 and 130 procedures/100 000 inhabitants in OECD countries in the 1990s. The crude overall hip implantation rate, summarising THR, partial hip replacement, and hip revision procedures, was reported to range from 60 to 200 procedures/100 000 inhabitants in the late 1990s. Moreover, large national differences were seen in the relationship between total and partial hip replacement procedures. Conclusion: The reported differences in hip replacement rates in OECD countries are substantial. They may be due to various causes, including different coding systems, country-specific differences in the healthcare system, in total expenditure on health per capita, in the population age structure, and in different indication criteria for THR. PMID:12594106

  11. Capsular Suspension Technique for Hip Arthroscopy

    PubMed Central

    Federer, Andrew E.; Karas, Vasili; Nho, Shane; Coleman, Struan H.; Mather, Richard C.

    2015-01-01

    Hip arthroscopy has recently become a common procedure to treat central and peripheral hip pathology. Capsulotomies are necessary in these procedures, and negotiating adequate visualization, as well as capsular preservation, is a challenge. We describe a capsular suspension technique that allows for adequate visualization of the central and peripheral compartments while facilitating preservation of the native hip capsule. This technique eliminates the need for additional personnel for retraction, potentially decreases iatrogenic hip injury, eliminates the need for excessive capsular debridement, and allows for capsular closure under minimal tension. PMID:26759769

  12. Life Estimation of Hip Joint Prosthesis

    NASA Astrophysics Data System (ADS)

    Desai, C.; Hirani, H.; Chawla, A.

    2014-11-01

    Hip joint is one of the largest weight-bearing structures in the human body. In the event of a failure of the natural hip joint, it is replaced with an artificial hip joint, known as hip joint prosthesis. The design of hip joint prosthesis must be such so as to resist fatigue failure of hip joint stem as well as bone cement, and minimize wear caused by sliding present between its head and socket. In the present paper an attempt is made to consider both fatigue and wear effects simultaneously in estimating functional-life of the hip joint prosthesis. The finite element modeling of hip joint prosthesis using HyperMesh™ (version 9) has been reported. The static analysis (load due to the dead weight of the body) and dynamic analysis (load due to walking cycle) have been described. Fatigue life is estimated by using the S-N curve of individual materials. To account for progressive wear of hip joint prosthesis, Archard's wear law, modifications in socket geometry and dynamic analysis have been used in a sequential manner. Using such sequential programming reduction in peak stress has been observed with increase in wear. Finally life is estimated on the basis of socket wear.

  13. Hip or knee replacement - before - what to ask your doctor

    MedlinePlus

    ... PA: Elsevier Mosby; 2012:chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain ... joint replacement - discharge Taking care of your new hip joint Review Date 3/5/2015 Updated by: C. ...

  14. Hip or knee replacement - after - what to ask your doctor

    MedlinePlus

    ... PA: Elsevier Mosby; 2012:chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain ... joint replacement - discharge Taking care of your new hip joint Review Date 3/5/2015 Updated by: C. ...

  15. Total hip arthroplasty after lower extremity amputation.

    PubMed

    Amanatullah, Derek F; Trousdale, Robert T; Sierra, Rafael J

    2015-05-01

    There are approximately 1.6 million lower extremity amputees in the United States. Lower extremity amputees are subject to increased physical demands proportional to their level of amputation. Lower extremity amputees have a 6-fold higher risk of developing radiographic osteoarthritis in the ipsilateral hip and a 2-fold risk of developing radiographic osteoarthritis in contralateral hip when compared with the non-amputee population. Additionally, there is a 3-fold increased risk of developing radiographic osteoarthritis in the ipsilateral hip after an above knee amputation when compared with a below knee amputation. The authors retrospectively reviewed 35 total hip arthroplasties after lower extremity amputation. The mean clinical follow-up was 5.3±4.0 years. The mean time from lower extremity amputation to total hip arthroplasty was 12.2±12.8 years after a contralateral amputation and 5.4±6.0 years after an ipsilateral amputation (P=.050). The mean time to total hip arthroplasty was 15.6±15.4 years after an above knee amputation and 6.4±6.1 years after a below knee amputation (P=.021). There was a statistically significant improvement in the mean Harris Hip Score from 35.9±21.8 to 76.8±12.8 with total hip arthroplasty after a contralateral amputation (P<.001). There also was a statistically significant improvement in the mean Harris Hip Score from 25.4±21.7 to 78.6±17.1 with total hip arthroplasty after an ispilateral amputation (P<.001). Three (17.7%) total hip arthroplasties after a contralateral amputation and 2 (11.1%) total hip arthroplasties after an ipsilateral amputation required revision total hip arthroplasty. Patients with an ipsilateral amputation or a below knee amputation progress to total hip arthroplasty faster than those with a contralateral amputation or an above knee amputation, respectively. Lower extremity amputees experience clinically significant improvements with total hip arthroplasty after lower extremity amputation.

  16. Hip disorders in the adolescent.

    PubMed

    Hotchkiss, Brian L; Engels, James A; Forness, Michael

    2007-05-01

    This article deals with common hip problems in the adolescent age group. Some of these problems, such as slipped capital femoral epiphysis, require urgent surgical treatment. Early detection is essential. Other problems, such as many of the athletic injuries, are less urgent but important to patients who desire rapid return to full athletic capacity. The emphasis here is on understanding the conditions and diagnosis. Surgical options are mentioned but not detailed. Office management, where appropriate, is discussed against the background of the natural history of the conditions. The intended audience is primary care physicians and orthopedic surgeons who may have limited exposure to some of these conditions.

  17. HIP Joining of Cemented Carbides

    SciTech Connect

    Derby, B.; Miodownik, M.

    1999-04-01

    Hot Isostatic Pressing (HIP) is investigated as a technique for joining the cermet WC-15% Co to itself. Encapsulation of the specimens prior to HIPing was carried out using steel encapsulation, glass encapsulation and self encapsulation. The bonds were evaluated using a four point bend method. It is shown that the glass and steel encapsulation methods have a number of inherent problems which make them inappropriate for near net shape processing. In contrast the novel self encapsulation method, described for the first time in this communication, is both simple and effective, producing joined material with bulk strength. The concept of self encapsulation is potentially widely applicable for joining composite materials.

  18. Burnishing Techniques Strengthen Hip Implants

    NASA Technical Reports Server (NTRS)

    2010-01-01

    In the late 1990s, Lambda Research Inc., of Cincinnati, Ohio, received Small Business Innovation Research (SBIR) awards from Glenn Research Center to demonstrate low plasticity burnishing (LPB) on metal engine components. By producing a thermally stable deep layer of compressive residual stress, LPB significantly strengthened turbine alloys. After Lambda patented the process, the Federal Aviation Administration accepted LPB for repair and alteration of commercial aircraft components, the U.S. Department of Energy found LPB suitable for treating nuclear waste containers at Yucca Mountain. Data from the U.S. Food and Drug Administration confirmed LPB to completely eliminate the occurrence of fretting fatigue failures in modular hip implants.

  19. Resurfacing weight bearing areas of the heel. The role of the dorsalis pedis innervated free tissue transfer.

    PubMed

    Duncan, M J; Zuker, R M; Manktelow, R T

    1985-01-01

    Five cases of chronic ulceration following skin graft resurfacing of the weight bearing surface of the heel are presented. All were managed with debridement and coverage with a free innervated dorsalis pedis tissue transfer. The technical refinements that have contributed to the reliability of the flap include careful distal identification of the first dorsal metatarsal artery (FDMA) and division of the dorsalis pedis artery (DPA) under direct vision below the takeoff of the FDMA. Donor site morbidity has been minimized by taking care to preserve the extensor paratenon as a bed for the subsequent skin graft and by immobilization of the donor foot with plaster and bed rest for 10 days. Four of the patients were followed for 2, 4, 4, and 6 years; one was lost to follow-up. All were active with protective sensation in their flaps. No instances of flap breakdown and no significant donor site morbidity were noted. The dorsalis pedis innervated free tissue transfer is recommended as a reliable procedure for resurfacing weight bearing areas of the foot when simpler methods have failed.

  20. Large-diameter total hip arthroplasty modular heads require greater assembly forces for initial stability

    PubMed Central

    MacLeod, A. R.; Sullivan, N. P. T.; Whitehouse, M. R.

    2016-01-01

    Objectives Modular junctions are ubiquitous in contemporary hip arthroplasty. The head-trunnion junction is implicated in the failure of large diameter metal-on-metal (MoM) hips which are the currently the topic of one the largest legal actions in the history of orthopaedics (estimated costs are stated to exceed $4 billion). Several factors are known to influence the strength of these press-fit modular connections. However, the influence of different head sizes has not previously been investigated. The aim of the study was to establish whether the choice of head size influences the initial strength of the trunnion-head connection. Materials and Methods Ti-6Al-4V trunnions (n = 60) and two different sizes of cobalt-chromium (Co-Cr) heads (28 mm and 36 mm; 30 of each size) were used in the study. Three different levels of assembly force were considered: 4 kN; 5 kN; and 6 kN (n = 10 each). The strength of the press-fit connection was subsequently evaluated by measuring the pull-off force required to break the connection. The statistical differences in pull-off force were examined using a Kruskal–Wallis test and two-sample Mann–Whitney U test. Finite element and analytical models were developed to understand the reasons for the experimentally observed differences. Results 36 mm diameter heads had significantly lower pull-off forces than 28 mm heads when impacted at 4 kN and 5 kN (p < 0.001; p < 0.001), but not at 6 kN (p = 0.21). Mean pull-off forces at 4 kN and 5 kN impaction forces were approximately 20% larger for 28 mm heads compared with 36 mm heads. Finite element and analytical models demonstrate that the differences in pull-off strength can be explained by differences in structural rigidity and the resulting interface pressures. Conclusion This is the first study to show that 36 mm Co-Cr heads have up to 20% lower pull-off connection strength compared with 28 mm heads for equivalent assembly forces. This effect is likely

  1. World-wide projections for hip fracture.

    PubMed

    Gullberg, B; Johnell, O; Kanis, J A

    1997-01-01

    The aims of this study were to estimate the present and future incidence of hip fracture world-wide. From a survey of available data on current incidence, population trends and the secular changes in hip fracture risk, the numbers of hip fractures expected in 2025 and 2050 were computed. The total number of hip fractures in men and women in 1990 was estimated to be 338,000 and 917,000 respectively, a total of 1.26 million. Assuming no change in the age- and sex-specific incidence, the number of hip fractures is estimated to approximately double to 2.6 million by the year 2025, and 4.5 million by the year 2050. The percentage increase will be greater in men (310%) than in women (240%). With modest assumptions concerning secular trends, the number of hip fractures could range between 7.3 and 21.3 million by 2050. The major demographic changes will occur in Asia. In 1990, 26% of all hip fractures occurred in Asia, whereas this figure could rise to 37% in 2025 and to 45% in 2050. We conclude that the socioeconomic impact of hip fractures will increase markedly throughout the world, particularly in Asia, and that there is an urgent need to develop preventive strategies, particularly in the developing countries.

  2. Sonography of Sports Injuries of the Hip

    PubMed Central

    Dawes, Aaron R. L.; Seidenberg, Peter H.

    2014-01-01

    Context: Sports-related injuries of the hip are a common complaint of both competitive and recreational athletes of all ages. The anatomic and biomechanical complexity of the hip region often cause diagnostic uncertainty for the clinicians evaluating these injuries. Therefore, obtaining additional diagnostic information is often crucial for providing injured athletes with a prompt and accurate diagnosis so they can return to activity as soon as possible. Musculoskeletal ultrasound is becoming increasingly important in evaluating and treating sports-related injuries of the hip. Evidence Acquisition: The PubMed database was searched in May of 2013 for English-language articles pertaining to sonography of sports injuries of the hip using the following keywords in various combinations: musculoskeletal, ultrasound, hip, hip sonography, and sports. Study Design: Clinical review. Level of Evidence: Level 4. Results: Musculoskeletal ultrasound is currently being used for both diagnosis and treatment in a wide range of acute and chronic conditions affecting the hip, including tendinosis, tendon/muscle strains, ligamentous sprains, enthesopathies, growth plate injuries, fractures, bursitis, effusions, synovitis, labral tears, and snapping hip. Therapeutically, it is used to guide injections, aspirations, and biopsies. Conclusion: Musculoskeletal ultrasound use is expanding and will likely continue to do so as more clinicians realize its capabilities. Characteristics, including accessibility, portability, noninvasiveness, dynamic examination, power Doppler examination, and low cost highlight the potential of ultrasound. PMID:25364486

  3. Process for HIP canning of composites

    NASA Technical Reports Server (NTRS)

    Juhas, John J. (Inventor)

    1990-01-01

    A single step is relied on in the canning process for hot isostatic pressing (HIP) metallurgy composites. The composites are made from arc sprayed and plasma sprayed monotape. The HIP can is of compatible refractory metal and is sealed at high vacuum and temperature. This eliminates outgassing during hot isostatic pressing.

  4. Implant Design in Cementless Hip Arthroplasty

    PubMed Central

    Kim, Jung Taek

    2016-01-01

    When performing cementless hip arthroplasty, it is critical to achieve firm primary mechanical stability followed by biological fixation. In order to achieve this, it is essential to fully understand characteristics of implant design. In this review, the authors review fixation principles for a variety of implants used for cementless hip replacement and considerations for making an optimal selection. PMID:27536647

  5. The Fatigue of Water Ice: Insight into the Tectonic Resurfacing of Tidally Deformed Icy Satellites

    NASA Astrophysics Data System (ADS)

    Hammond, N. P.; Barr, A. C.; Hirth, G.; Cooper, R. F.

    2015-12-01

    allow us to determine how subcritical crack growth rates vary as a function of stress intensity, temperature and frequency. We will use our data to extrapolate to conditions present in the near-surface of icy satellites to determine the effect of fatigue on icy satellite resurfacing. [1] Hubner H. and Jillik J., (1977) J. Material Sci. 12.

  6. A new modality for fractional CO2 laser resurfacing for acne scars in Asians.

    PubMed

    Huang, Luping

    2013-02-01

    improvement of >75 %. This new modality of ablative conventional CO2 laser therapy with fractional CO2 laser resurfacing was shown to be safe and efficacious in the treatment of acne scars in Asian patients. It did not increase the risk of PIH compared to other reports of laser therapy and PIH. It is the hope that future study with combination therapy will further enhance the clinical results and thus lessen potential adverse events.

  7. Interventional MSK procedures: the hip

    PubMed Central

    Lefebvre, Guillaume; Cockenpot, Eric; Chastanet, Patrick; Cotten, Anne

    2016-01-01

    Percutaneous musculoskeletal procedures are widely accepted as low invasive, highly effective, efficient and safe methods in a vast amount of hip pathologies either in diagnostic or in therapeutic management. Hip intra-articular injections are used for the symptomatic treatment of osteoarthritis. Peritendinous or intrabursal corticosteroid injections can be used for the symptomatic treatment of greater trochanteric pain syndrome and anterior iliopsoas impingement. In past decades, the role of interventional radiology has rapidly increased in metastatic disease, thanks to the development of many ablative techniques. Image-guided percutaneous ablation of skeletal metastases provides a minimally invasive treatment option that appears to be a safe and effective palliative treatment for localized painful lytic lesion. Methods of tumour destruction based on temperature, such as radiofrequency ablation (RFA) and cryotherapy, are performed for the management of musculoskeletal metastases. MR-guided focused ultrasound surgery provides a non-invasive alternative to these ablative methods. Cementoplasty is now widely used for pain management and consolidation of acetabular metastases and can be combined with RFA. RFA is also used to treat benign tumours, namely osteoid osteomas. New interventional procedures such as percutaneous screw fixation are also proposed to treat non-displaced or minimally displaced acetabular roof fractures. PMID:26317896

  8. Asymmetric Hip Rotation in Professional Baseball Pitchers

    PubMed Central

    McCulloch, Patrick C.; Patel, Jayesh K.; Ramkumar, Prem N.; Noble, Philip C.; Lintner, David M.

    2014-01-01

    Background: There is a renewed interest in examining the association between hip range of motion and injury in athletes, and the data on baseball players are conflicting. Understanding whether asymmetrical hip rotation is a normal adaptation or a risk factor for injury will help therapists, trainers, and physicians develop rehabilitation programs to improve kinetic energy transfer and prevent injury. As our knowledge of hip pathology among baseball pitchers improves, establishing baselines for hip motion is critical in the further assessment of injury. Hypothesis: Because of the repetitive nature of throwing sports and the adaptive changes documented in the shoulder, elite baseball pitchers would have characteristic patterns of hip internal and external rotations on their dominant throwing side (stance) and their nondominant side (stride) in extension. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Computer software was used to measure passive internal and external rotations on digital photographs of 111 professional baseball pitchers. Results: In right-handed pitchers, there was significantly more internal rotation in the stance hip than the stride hip (32.2° ± 8.2° vs 30.8° ± 8.4°; P = .0349) and significantly more external rotation in the stride hip than the stance hip (36.3° ± 7.7° vs 30.8° ± 9.7°; P < .0001). While the mean difference in external rotation was 4.7°, 32% of the subjects had a >10° increase in external rotation on the stride hip relative to the stance hip. This population was statistically different from the remaining group for older age (P = .0053), lower body mass index (P = .0379), and more years in professional baseball (P = .0328). In the smaller number of left-handed pitchers, side-to-side differences in hip rotation were found but were not statistically significant. Conclusion: Pitchers showed more internal rotation on their stance hip and more external rotation on their stride hip. Although the mean

  9. Growth and development of the child's hip.

    PubMed

    Lee, Mark C; Eberson, Craig P

    2006-04-01

    The child's hip begins in intrauterine development as a condensation of mesoderm in the lower limb bud that rapidly differentiates to resemble the adult hip by eight weeks of life. The developmental instructions are transmitted through complicated cell signaling pathways. From eight weeks of development to adolescence, further growth of the hip is focused on differentiation and the establishment of the adult arterial supply. The postnatal growth of the child's hip is a product of concurrent acetabular and proximal femoral growth from their corresponding growth plates. Absence of appropriate contact between acetabulum and proximal femur yields an incongruent joint. Multiple disease processes may be understood in light of this growth process, including Legg-Calvé-Perthes disease and developmental dysplasia of the hip.

  10. Reconstruction of the Acetabulum in Developmental Dysplasia of the Hip in total hip replacement

    PubMed Central

    Sakellariou, Vasileios I.; Christodoulou, Michael; Sasalos, Gregory; Babis, George C.

    2014-01-01

    Developmental dysplasia of the hip (DDH) or congenital hip dysplasia (CDH) is the most prevalent developmental childhood hip disorder. It includes a wide spectrum of hip abnormalities ranging from dysplasia to subluxation and complete dislocation of the hip joint. The natural history of neglected DDH in adults is highly variable. The mean age of onset of symptoms is 34.5 years for dysplastic DDH, 32.5 years for low dislocation, 31.2 years for high dislocation with a false acetabulum, and 46.4 years for high dislocation without a false acetabulum. Thorough understanding of the bony and soft tissue deformities induced by dysplasia is crucial for the success of total hip arthroplasty. It is important to evaluate the existing acetabular deformity three-dimensionally, and customize the correction in accordance with the quantity and location of ace tabular deficiencies. Acetabular reconstruction in patients with DDH is challenging. Interpretation of published data is difficult and should be done with caution because most series include patients with different types of hip disease. In general, the complication rate associated with THA is higher in patients with hip dysplasia than it is in patients with osteoarthritis. Overall, clinical and functional outcomes following THA in patients hip dysplasia (DDH) differ from those treated for primary hip osteoarthritis, possibly due to the lower age and level of activity. Although function scores decline with age, the scores for pain and range of motion presented with a statistically significant improvement in the long-term. PMID:25386570

  11. Hip instability: a review of hip dysplasia and other contributing factors

    PubMed Central

    Kraeutler, Matthew J.; Garabekyan, Tigran; Pascual-Garrido, Cecilia; Mei-Dan, Omer

    2016-01-01

    Summary Background Hip instability has classically been associated with developmental dysplasia of the hip (DDH) in newborns and children. However, numerous factors may contribute to hip instability in children, adolescents, and adults. Purpose This review aims to concisely present the literature on hip instability in patients of all ages in order to guide health care professionals in the appropriate diagnosis and treatment of the various disorders which may contribute to an unstable hip. Methods We reviewed the literature on the diagnosis and surgical management of hip dysplasia and other causes of hip instability. Conclusions Multiple intra- and extra-articular variables may contribute to hip instability, including acetabular bony coverage, femoral torsion, femoroacetabular impingement, and soft tissue laxity. Physical examination and advanced imaging studies are essential to accurately diagnose the pathology contributing to a patient’s unstable hip. Conservative management, including activity modification and physical therapy, may be used as a first-line treatment in patients with intra-articular hip pathology. Patients who continue to experience symptoms of pain or instability should proceed with arthroscopic or open surgical treatment aimed at correcting the underlying pathology. Level of evidence V. PMID:28066739

  12. Mechanical Evaluation of Polymer Composite Hip Protectors

    PubMed Central

    Melo, Jose Daniel Diniz; Barbosa, Ayrles S. Gonçalves; Guerra, Ricardo Oliveira

    2010-01-01

    Hip fractures often result in serious health implications, particularly in the geriatric population, and have been related to long-term morbidity and death. In most cases, these fractures are caused by impact loads in the area of the greater trochanter, which are produced in a fall. This work is aimed at developing hip protectors using composite materials and evaluating their effectiveness in preventing hip fractures under high impact energy (120 J). The hip protectors were developed with an inner layer of energy absorbing soft material and an outer rigid shell of fiberglass-reinforced polymer composite. According to the experimental results, all tested configurations proved to be effective at reducing the impact load to below the average fracture threshold of proximal femur. Furthermore, an addition of Ethylene Vinyl Acetate (EVA) to the impacted area of the composite shell proved to be beneficial to increase impact strength of the hip protectors. Thus, composite hip protectors proved to be a viable alternative for a mechanically efficient and cost-effective solution to prevent hip fractures. PMID:20871841

  13. Epidemiology of osteoporotic hip fractures in Spain

    PubMed Central

    Martínez, Angel Antonio; Ferrandez, Luis; Gil, Enrique; Moreno, Alonso

    2005-01-01

    We conducted a multicentre study, divided into a retrospective and a prospective portion. The retrospective study evaluated osteoporotic hip fractures that occurred during 2002. The prospective study evaluated osteoporotic hip fractures that occurred during May 2003. The study was conducted in 77 hospitals in Spain and comprised patients 60 years of age and over. In the retrospective study we registered 13,195 hip fractures. Of the patients, 74% were women and 26% were men. The mean age was 80.7±8.4 years. The average incidence was 6.94±0.44 hip fractures per 1,000 inhabitants/year (95% CI, 6.07–7.82). In the prospective study, we registered 1,399 hip fractures. This represents a monthly incidence of 0.60±0.04 hip fractures per 1,000 inhabitants/year (95% CI, 0.51–0.69). Of the subjects, 74% were women and 26% were men. The mean age was 81.4±8.1 years. Using these data, we calculated the average annual prevalence in 2003 to be 7.20 fractures per 1,000 inhabitants. Thirty-three percent had previously suffered a hip fracture. Prior to the fracture, only 18% had received medical treatment for osteoporosis. After discharge from the hospital, only 26% were receiving pharmacological treatment for osteoporosis. PMID:16328387

  14. [Bilateral Asymmetric Traumatic Dislocation of Hip Joints].

    PubMed

    Paša, L; Veselý, R; Kelbl, M

    2017-01-01

    The authors present a rare case of bilateral asymmetric traumatic dislocation of hip joints, where the left joint was treated conservatively after the reduction, while the right joint, with an acetabular fragment interposition, was treated surgically - by arthroscopically assisted reduction and fixation of an osteochondral fragment of posterior wall of the acetabulum. The female patient healed with no complications, showing an excellent clinical outcome with no signs of instability or limited mobility of hip joints, and also with no signs of para-articular calcification or necrosis of the hip at 1 year after the injury and treatment. Bilateral asymmetric dislocation of hip joint is a rare injury with the total incidence of 150 cases as reported by the literature. Recently, its incidence is higher due to the increased traffic and the associated accident rate. A precise and prompt reduction of the injured hip joint is always necessary, if possible under general anesthesia. Also, it is always necessary to carry out a complete examination of the patient since this type of injury is always caused by a strong force and is often accompanied by injuries of other parts of the body. Key words: bilateral asymmetric dislocation of hip joints, hip arthroscopy, acetabular fracture.

  15. The Danish Hip Arthroplasty Register

    PubMed Central

    Gundtoft, Per Hviid; Varnum, Claus; Pedersen, Alma Becic; Overgaard, Søren

    2016-01-01

    Aim of database The aim of the Danish Hip Arthroplasty Register (DHR) is to continuously monitor and improve the quality of treatment of primary and revision total hip arthroplasty (THA) in Denmark. Study population The DHR is a Danish nationwide arthroplasty register established in January 1995. All Danish orthopedic departments – both public and private – report to the register, and registration is compulsory. Main variables The main variables in the register include civil registration number, indication for primary and revision surgery, operation date and side, and postoperative complications. Completeness of primary and revision surgery is evaluated annually and validation of a number of variables has been carried out. Descriptive data A total of 139,525 primary THAs and 22,118 revisions have been registered in the DHR between January 1, 1995 and December 31, 2014. Since 1995, completeness of procedure registration has been high, being 97.8% and 92.0% in 2014 for primary THAs and revisions, respectively. Several risk factors, such as comorbidity, age, specific primary diagnosis and fixation types for failure of primary THAs, and postoperative complications, have been identified through the DHR. Approximately 9,000 primary THAs and 1,500 revisions are reported to the register annually. Conclusion The DHR is important for monitoring and improvement of treatment with THA and is a valuable tool for research in THA surgery due to the high quality of prospective collected data with long-term follow-up and high completeness. The register can be used for population-based epidemiology studies of THA surgery and can be linked to a range of other national databases. PMID:27822092

  16. Epidemiology of hip fractures in Norway.

    PubMed

    Falch, J A; Ilebekk, A; Slungaard, U

    1985-02-01

    During the 2-year period 1978-1979, a total of 2109 hip fractures (of the proximal end of the femur) occurred in Oslo. The age- and sex-specific annual incidence was the highest ever reported. A previous hip fracture had occurred in 13 per cent of the women and 6.8 per cent of the men. In 1979, a total of 5920 hip fractures was reported in Norway. Compared with Oslo, all other counties had a lower incidence. The number of fractures in Oslo was five times greater in 1982 compared with 1950. This increase cannot be explained only by the increasing number of elderly persons.

  17. [Dysplasia in the development of the hip].

    PubMed

    Moraleda, L; Albiñana, J; Salcedo, M; Gonzalez-Moran, G

    2013-01-01

    Developmental dysplasia of the hip (DDH) causes anatomical changes that cause early coxarthrosis. Although risf factors have been determined, the aetiology and physiopathology remains exactly unknown. Neonatal screening with physical examination and ultrasound have been stablished in order to diagnose this disease early in life. A diagnosis in the first months of life is essential as it enables a normal hip to form and prevent the appearance of early coxarthrosis. Treatment principles are to be able to reduce the hip without provoking avascular necrosis of the femoral head, and to normalize the acetabular development. Knowledge of the orthopaedic and surgical options is essential in order to achieve success in the treatment.

  18. Flap prefabrication and stem cell-assisted tissue expansion: how we acquire a monoblock flap for full face resurfacing.

    PubMed

    Li, Qingfeng; Zan, Tao; Li, Haizhou; Zhou, Shuangbai; Gu, Bin; Liu, Kai; Xie, Feng; Xie, Yun

    2014-01-01

    Total face skin and soft-tissue defects remain one of the biggest challenges in reconstructive surgery. Reconstruction of the entire face with uniform coverage and delicate features is difficult to achieve. To avoid the patchwork result seen in multiple flaps and skin grafts, 1 monoblock flap that has similar color, texture, and thickness might be an ideal option to minimize the incisional scars and several surgical procedures but is unavailable with current approaches because of the lack of sufficient matched tissue and the unreliable blood supply for such a large flap. To acquire a monoblock flap for full face reconstruction, we combine the prefabricated flaps, skin overexpansion, and bone marrow mononuclear stem cell transplantation for total facial resurfacing. In this article, we present our experience from our case series that provides universally matched skin and near-normal facial contour. It is a reliable and an excellent reconstructive option for massive facial skin defect.

  19. Living history in current orthopaedic hip surgery: intrapelvic teflon granuloma after total hip replacement.

    PubMed

    Gheorghiu, Daniel; Peter, Viju; Lynch, Martin

    2010-02-01

    The teflon hip arthroplasty design was used by Sir John Charnley in the early 60's but was taken off the market due to high complication rates. A case is reported of an intrapelvic granuloma after total hip arthroplasty following the use of a teflon socket. This appears to be the last surviving patient treated by Sir John Charnley using a Teflon hip socket design.

  20. Detecting volcanic resurfacing of heavily cratered terrain: Flooding simulations on the Moon using Lunar Orbiter Laser Altimeter (LOLA) data

    NASA Astrophysics Data System (ADS)

    Whitten, Jennifer L.; Head, James W.

    2013-09-01

    Early extrusive volcanism from mantle melting marks the transition from primary to secondary crust formation. Detection of secondary crust is often obscured by the high impact flux early in solar system history. To recognize the relationship between heavily cratered terrain and volcanic resurfacing, this study documents how volcanic resurfacing alters the impact cratering record and models the thickness, area, and volume of volcanic flood deposits. Lunar Orbiter Laser Altimeter (LOLA) data are used to analyze three different regions of the lunar highlands: the Hertzsprung basin; a farside heavily cratered region; and the central highlands. Lunar mare emplacement style is assumed to be similar to that of terrestrial flood basalts, involving large volumes of material extruded from dike-fed fissures over relatively short periods of time. Thus, each region was flooded at 0.5 km elevation intervals to simulate such volcanic flooding and to assess areal patterns, thickness, volumes, and emplacement history. These simulations show three primary stages of volcanic flooding: (1) Initial flooding is largely confined to individual craters and deposits are thick and localized; (2) basalt flows breach crater rim crests and are emplaced laterally between larger craters as thin widespread deposits; and (3) lateral spreading decreases in response to regional topographic variations and the deposits thicken and bury intermediate-sized and larger craters. Application of these techniques to the South Pole-Aitken basin shows that emplacement of ∼1-2 km of cryptomaria can potentially explain the paucity of craters 20-64 km in diameter on the floor of the basin relative to the distribution in the surrounding highlands.

  1. Pulsed and scanned carbon dioxide laser resurfacing 2 years after treatment: comparison by means of scanning electron microscopy.

    PubMed

    Trelles, Mario A; Garcia, Luisa; Rigau, Josepa; Allones, Inès; Velez, Marìano

    2003-05-01

    Studies have reported short-term and long-term (1-year) findings for laser skin resurfacing. Two of the most popular systems used for this procedure, the continuous-wave Sharplan 40C SilkTouch system and the pulsed Coherent 5000C UltraPulse system with a computer pattern generator, were previously compared for a range of follow-up times up to 1 year, using light microscopy and transmission electron microscopy. This study analyzed the 2-year morphological differences using scanning electron microscopy. Tissue samples were obtained from 10 patients (age range, 50 to 72 years; skin types II and III) who had undergone laser resurfacing 2 years previously. One half of the face of each patient had been treated with the continuous-wave system and the other half with the pulsed system. The samples were subjected to scanning electron microscopy. On the continuous-wave-treated side, significantly better dermal collagen organization was observed at 2 years, with plump-appearing fibers that were closely knit to form a compact structure. On the side treated with the pulsed system, the collagen fibers in the papillary dermis were more loosely arranged and appeared drier. In both the continuous-wave-treated and pulsed-treated areas, the epidermis appeared healthy and exhibited some signs of age-related deterioration, with slightly flatter plaques and somewhat more flaking keratin on the pulsed-treated side. Probably because of the greater degree of residual thermal damage associated with the continuous-wave system, at 2 years after treatment there was more prolific synthesis and better orientation of collagen fibers, which were maintained for longer times, compared with the pulsed-treated specimens.

  2. Improving the outcome of fractional CO2 laser resurfacing using a probiotic skin cream: Preliminary clinical evaluation.

    PubMed

    Zoccali, Giovanni; Cinque, Benedetta; La Torre, Cristina; Lombardi, Francesca; Palumbo, Paola; Romano, Lucia; Mattei, Antonella; Orsini, Gino; Cifone, Maria Grazia; Giuliani, Maurizio

    2016-11-01

    As known, fractional CO2 resurfacing treatments are more effective than non-ablative ones against aging signs, but post-operative redness and swelling prolong the overall downtime requiring up to steroid administration in order to reduce these local systems. In the last years, an increasing interest has been focused on the possible use of probiotics for treating inflammatory and allergic conditions suggesting that they can exert profound beneficial effects on skin homeostasis. In this work, the Authors report their experience on fractional CO2 laser resurfacing and provide the results of a new post-operative topical treatment with an experimental cream containing probiotic-derived active principles potentially able to modulate the inflammatory reaction associated to laser-treatment. The cream containing DermaACB (CERABEST™) was administered post-operatively to 42 consecutive patients who were treated with fractional CO2 laser. All patients adopted the cream twice a day for 2 weeks. Grades were given according to outcome scale. The efficacy of the cream containing DermaACB was evaluated comparing the rate of post-operative signs vanishing with a control group of 20 patients topically treated with an antibiotic cream and a hyaluronic acid based cream. Results registered with the experimental treatment were good in 22 patients, moderate in 17, and poor in 3 cases. Patients using the study cream took an average time of 14.3 days for erythema resolution and 9.3 days for swelling vanishing. The post-operative administration of the cream containing DermaACB induces a quicker reduction of post-operative erythema and swelling when compared to a standard treatment.

  3. Resurfacing history of the northern plains of Mars based on geologic mapping of Mars Global Surveyor data

    USGS Publications Warehouse

    Tanaka, K.L.; Skinner, J.A.; Hare, T.M.; Joyal, T.; Wenker, A.

    2003-01-01

    Geologic mapping of the northern plains of Mars, based on Mars Orbiter Laser Altimeter topography and Viking and Mars Orbiter Camera images, reveals new insights into geologic processes and events in this region during the Hesperian and Amazonian Periods. We propose four successive stages of lowland resurfacing likely related to the activity of near-surface volatiles commencing at the highland-lowland boundary (HLB) and progressing to lower topographic levels as follows (highest elevations indicated): Stage 1, upper boundary plains, Early Hesperian, <-2.0 to -2.9 km; Stage 2, lower boundary plains and outflow channel dissection, Late Hesperian, <-2.7 to -4.0 km; Stage 3, Vastitas Borealis Formation (VBF) surface, Late Hesperian to Early Amazonian, <-3.1 to -4.1 km; and Stage 4, local chaos zones, Early Amazonian, <-3.8 to -5.0 km. At Acidalia Mensa, Stage 2 and 3 levels may be lower (<-4.4 and -4.8 km, respectively). Contractional ridges form the dominant structure in the plains and developed from near the end of the Early Hesperian to the Early Amazonian. Geomorphic evidence for a northern-plains-filling ocean during Stage 2 is absent because one did not form or its evidence was destroyed by Stage 3 resurfacing. Remnants of possible Amazonian dust mantles occur on top of the VBF. The north polar layered deposits appear to be made up of an up to kilometer-thick lower sequence of sandy layers Early to Middle Amazonian in age overlain by Late Amazonian ice-rich dust layers; both units appear to have outliers, suggesting that they once were more extensive.

  4. Deciding to have knee or hip replacement

    MedlinePlus

    ... the hip In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ... the knee. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ...

  5. Risks of hip and knee replacement

    MedlinePlus

    ... the hip In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ... the knee. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ...

  6. American Association of Hip and Knee Surgeons

    MedlinePlus

    ... Programs Performance & Quality Practice Management FARE – AAHKS Foundation Partner With AAHKS AAHKS Committee Orientation AJRR 2016 Annual Report Hip and Knee Online Exam Page AAHKS Business Reports AAHKS Committee Orientation AAHKS News 2014 AAHKS ...

  7. Taking care of your new hip joint

    MedlinePlus

    ... AL. Total hip replacement. In: Frontera, WR, Silver JK, Rizzo TD, eds. Essentials of Physical Medicine and ... TE. Total knee replacement. In: Frontera, WR, Silver JK, Rizzo TD, eds. Essentials of Physical Medicine and ...

  8. Microbial assisted High Impact Polystyrene (HIPS) degradation.

    PubMed

    Mohan, Arya J; Sekhar, Vini C; Bhaskar, Thallada; Nampoothiri, K Madhavan

    2016-08-01

    The efficacy of newly isolated Pseudomonas and Bacillus strains to degrade brominated High Impact Polystyrene (HIPS) was investigated. Viability of these cultures while using e-plastic as sole carbon source was validated through Triphenyl Tetrazolium Chloride (TTC). Four days incubation of HIPS emulsion with Bacillus spp. showed 94% reduction in turbidity and was 97% with Pseudomonas spp. Confirmation of degradation was concluded by HPLC, NMR, FTIR, TGA and weight loss analysis. NMR spectra of the degraded film revealed the formation of aliphatic carbon chain with bromine and its release. FTIR analysis of the samples showed a reduction in CH, CO and CN groups. Surface changes in the brominated HIPS film was visualized through SEM analysis. Degradation with Bacillus spp showed a weight loss of 23% (w/w) of HIPS film in 30days.

  9. Understanding and Treating the Snapping Hip

    PubMed Central

    Yen, Yi-Meng; Lewis, Cara L.; Kim, Young-Jo

    2016-01-01

    Snapping hip, or coxa saltans is a palpable or auditory snapping with movement of the hip joint. Extra-articular snapping is divided into external and internal types, and is caused laterally by the iliotibial band and anteriorly by the iliopsoas tendon. Snapping of the iliopsoas usually requires contraction of the hip flexors and may be difficult to distinguish from intra-articualar coxa saltans. Ultrasound can be a useful modality to dynamically detect tendon translation during hip movement to support the diagnosis of extra-articular snapping. Coxa saltans is typically treated with conservative measures including anti-inflammatories, stretching and avoidance of inciting activities. Recalcitrant cases are treated with surgery to lengthen the iliopsoas or iliotibial band. PMID:26524554

  10. An overview of hip injuries in running.

    PubMed

    Paluska, Scott A

    2005-01-01

    Running has steadily gained in worldwide popularity and is the primary exercise modality for many individuals of all ages. Its low cost, versatility, convenience and related health benefits appeal to men and women of broad cultural, ethnic and economic backgrounds. With more children and adults participating in recreational and competitive running, the incidence of injuries has steadily increased. Most running-related injuries affecting the lower extremities are due to preventable training errors, and some may necessitate medical evaluation or a significant reduction in training. Hip injuries in runners are due to interactions of intrinsic and extrinsic factors that adversely affect the complex regional anatomy. Acute or chronic hip pain presents a diagnostic and therapeutic challenge because the vague, nonspecific symptoms and signs may originate from local, regional or distant foci. Muscle strains and tendonitis are the most common aetiologies of hip pain and typically result from sudden acceleration/deceleration manoeuvres, direction changes or eccentric contractions. Apophysitis and avulsion fractures may affect younger runners and produce localised pain at muscle attachment sites. Iliotibial band syndrome is a common cause of lateral hip and knee symptoms characterised by sharp or burning pain that is exacerbated by activity. Bursitis, due to repetitive activity or acute trauma, may affect the trochanteric, ischial or iliopectineal bursae. Hip osteoarthritis may also produce persistent pain that worsens with running. Stress fractures are potentially serious conditions that affect women more frequently than men. Snapping hip syndrome is a benign condition that results from tight connective tissues' passing repeatedly over the greater trochanter, anterior hip capsule, lesser trochanter, femoral head or iliopectineal eminence. Acetabular labral tears, sports hernias and nerve entrapment syndromes are also potential causes of persistent hip pain in runners

  11. [Treatment of hip fractures in elderly patients].

    PubMed

    Hack, Juliana; Bliemel, Christopher; Ruchholtz, Steffen; Bücking, Benjamin

    2015-04-01

    Hip fractures are among the most common fractures in elderly people. The annual number of femoral fractures is even expected to increase because of an aging society. Due to the high number of comorbidities, there are special challenges in treating geriatric hip fracture patients, which require a multidisciplinary management. This includes surgical treatment allowing full weight bearing in the immediate postoperative period, osteoporosis treatment and falls prevention as well as an early ortho-geriatric rehabilitation program.

  12. Celiac Disease in Women with Hip Fractures

    PubMed Central

    LeBoff, Meryl S.; Cobb, Haley; Gao, Lisa Y.; Hawkes, William; Yu-Yahiro, Janet; Kolatkar, Nikheel S.; Magaziner, Jay

    2014-01-01

    Objective Celiac disease is associated with decreased bone density, however, the risk of fractures in celiac disease patients is unclear. We compared the prevalence of celiac disease between a group of women with hip fractures and a group of women undergoing elective joint replacement surgery and the association between celiac disease and vitamin D levels. Methods Two hundred eight community dwelling and postmenopausal women were recruited from Boston, MA (n=81) and Baltimore, MD (n=127). We measured tissue transglutaminase IgA by ELISA to diagnose celiac disease and 25-hydroxyvitamin D (25(OH)D) levels by radioimmunoassay in both women with hip fractures (n=157) and the control group (n=51), all of whom were from Boston. Subjects were excluded if they took any medications or had medical conditions that might affect bone. Results Median serum 25(OH)D levels were significantly lower (p< 0.0001) in the hip fracture cohorts compared to the elective joint replacement cohort (14.1 ng/ml vs. 21.3 ng/ml, respectively). There were no differences in the percentage of subjects with a positive tissue transglutaminase in the women with hip fractures versus the control group (1.91% vs. 1.61%, respectively). Conclusion Vitamin D levels are markedly reduced in women with hip fractures, however hip fracture patients did not show a higher percentage of positive tissue transglutaminase levels compared with controls. These data suggest that routine testing for celiac disease among hip fracture patients may not prove useful, although larger prospective studies among hip fracture subjects are needed. PMID:23732553

  13. NEW BEARING SURFACES IN TOTAL HIP REPLACEMENT

    PubMed Central

    Schwartsmann, Carlos Roberto; Boschin, Leonardo Carbonera; Gonçalves, Ramiro Zilles; Yépez, Anthony Kerbes; de Freitas Spinelli, Leandro

    2015-01-01

    Total hip arthroplasty is being increasingly indicated for younger and more active patients, in addition to a naturally growing demand for the procedure because of increasing life expectancy among patients. The high costs of this surgery and the controversies regarding implant performance have made this topic the subject of constant research, seeking new materials with better resistance to wear and better biocompatibility. The present article provides a review of new surfaces in total hip arthroplasty. PMID:27042614

  14. Femoral osteolysis following total hip replacement

    PubMed Central

    Dattani, R

    2007-01-01

    Total hip replacement represents the most significant advance in orthopaedic surgery in the 20th century. Periprosthetic osteolysis remains the most significant long‐term complication with total hip replacement. It has been reported with all materials and prosthetic devices in use or that have been used to date. This paper reviews the current thinking on the aetiology, pathogenesis, management and future treatment options for osteolysis. PMID:17488859

  15. Current Concepts in Hip Preservation Surgery

    PubMed Central

    Adler, Kelly L.; Cook, P. Christopher; Yen, Yi-Meng; Giordano, Brian D.

    2015-01-01

    Context: An evolution in conceptual understanding, coupled with technical innovations, has enabled hip preservation surgeons to address complex pathomorphologies about the hip joint to reduce pain, optimize function, and potentially increase the longevity of the native hip joint. Technical aspects of hip preservation surgeries are diverse and range from isolated arthroscopic or open procedures to hybrid procedures that combine the advantages of arthroscopy with open surgical dislocation, pelvic and/or proximal femoral osteotomy, and biologic treatments for cartilage restoration. Evidence Acquisition: PubMed and CINAHL databases were searched to identify relevant scientific and review articles from January 1920 to January 2015 using the search terms hip preservation, labrum, surgical dislocation, femoroacetabular impingement, peri-acetabular osteotomy, and rotational osteotomy. Reference lists of included articles were reviewed to locate additional references of interest. Study Design: Clinical review. Level of Evidence: Level 4. Results: Thoughtful individualized surgical procedures are available to optimize the femoroacetabular joint in the presence of hip dysfunction. Conclusion: A comprehensive understanding of the relationship between femoral and pelvic orientation, morphology, and the development of intra-articular abnormalities is necessary to formulate a patient-specific approach to treatment with potential for a successful long-term result. PMID:26502445

  16. Incidence of hip fractures in Korea.

    PubMed

    Lim, Soo; Koo, Bo Kyeong; Lee, Eun Jung; Park, Jin Ho; Kim, Myoung Hee; Shin, Kun Hong; Ha, Yong Chan; Cho, Nam Han; Shin, Chan Soo

    2008-01-01

    Osteoporosis is a major public health problem in both Western and Asian populations. Because the aged population in Korea is increasing, the number of osteoporotic fractures is thought to be also increasing. However, there has been no nationwide analysis of osteoporotic fractures in Korea. We analyzed the incidence and cost of hip fracture from 2001 to 2004 by using data from the Health Insurance Review Agency, Korea. In the over 50 years age group, the number of hip fractures in women increased from 250.9/100,000 persons in 2001 to 262.8/100,000 in 2004, a 4.7% increase. However, that in men decreased from 162.8/100,000 in 2001 to 137.5/100,000 in 2004, a 15.5% decrease. Direct medical care costs of hip fracture increased from $62,707,697 in 2001 to $65,200,035 in 2004, and the proportional cost of hip fractures in the national medical costs increased by 4.5% over 4 years (from 0.200% in 2001 to 0.209% in 2004). On analysis of the population-based data obtained from the whole country from 2001 to 2004, the incidence rate of hip fractures in women, not in men, and its cost have increased in Korea. The gender distribution of hip fractures underlines the need for aggressive intervention in osteoporosis in elderly women.

  17. Quality of life impairments after hip arthroscopy in people with hip chondropathy

    PubMed Central

    Filbay, Stephanie R.; Kemp, Joanne L.; Ackerman, Ilana N.; Crossley, Kay M.

    2016-01-01

    Many young individuals undergoing hip arthroscopic surgery have hip chondropathy. The impact of mild or more severe hip chondropathy 1–2 years following arthroscopy is poorly understood. The purpose of this study was to (i) compare health-related quality of life (HRQoL), anxiety and depression scores between people who underwent arthroscopic treatment for hip chondropathy 1–2 years previously and pain-free controls; (ii) compare HRQoL, hip-related quality of life (QoL) and anxiety/depression scores in people with mild versus severe hip chondropathy and (iii) compare hip-related QoL items between chondropathy groups. The Hip disability and Osteoarthritis Outcome Score (HOOS), International Hip Outcome Tool (iHOT-33), EuroQol-5D and Hospital Anxiety and Depression Scale (HADS) were compared between 71 individuals aged 18–60 years following arthroscopic treatment for hip chondroplasty (12–24 months previously) and 46 healthy controls. Comparisons were also performed between people with mild (Outerbridge grade 1–2) and severe (Outerbridge grade 3–4) hip chondropathy. Participants following arthroscopic treatment for hip chondroplasty reported worse HRQoL, hip-related QoL and anxiety, compared with pain-free controls (all P < 0.05), but no difference in self-care (P = 0.20). There were differences between mild and severe chondropathy groups for pain during sport/recreation [median (IQR) 20 (5–80) versus 60 (25–90) P = 0.01), pain after activity (40 (20–75) versus 75 (50–90) P = 0.01), difficulty maintaining fitness (30 (10–70) versus 75 (35–85) P = 0.02) and reduced hip confidence. Hip chondropathy was associated with significant QoL impairment, with severe chondropathy associated with the greatest impairment. The identification of specific areas of QoL impairment provides avenues to target rehabilitation and support. PMID:27583152

  18. Surgical hip dislocation does not result in atrophy or fatty infiltration of periarticular hip muscles

    PubMed Central

    Glynn, Aaron A.; Barattiero, Fabio Y.; Albers, Christoph E.; Hanke, Markus S.; Steppacher, Simon D.; Tannast, Moritz

    2014-01-01

    Surgical hip dislocation is the gold standard for treatment of femoroacetabular impingement (FAI). It utilizes an intermuscular and internervous approach to the hip. Concerns have been expressed that this approach causes soft tissue trauma resulting in post-operative muscle weakness of patients undergoing this procedure. We therefore asked whether surgical hip dislocation leads to (i) atrophy (decreased muscle diameter or cross-sectional area [CSA]) and (ii) degeneration (fatty infiltration) of 18 evaluated periarticular hip muscles. We retrospectively evaluated 32 patients (34 hips) following surgical hip dislocation for the treatment of FAI using pre and post-operative magnetic resonance (MR) arthrography of the hip. We evaluated muscle diameter, CSA and degree of fatty infiltration according to Goutallier for 18 periarticular hip muscles on axial and sagittal views. The mean interval between pre and post-operative MR was 1.9 ± 1.5 years (range, 0.4–6.1 years). Pre and post-operative muscle diameter and CSA of all 18 evaluated hip muscles did not differ. There was no post-operative change in the Goutallier classification for any of the evaluated 18 muscles. No muscle had post-operative degeneration higher than Grade 1 according to Goutallier. No atrophy or degeneration of periarticular hip muscles could be found following surgical hip dislocation for treatment of FAI. Any raised concerns about the invasiveness and potential muscle trauma for this type of surgery are unfounded. Level III, retrospective comparative study. See guidelines for authors for a complete description of levels of evidence. PMID:27011807

  19. Postoperative Rehabilitation Guidelines for Hip Arthroscopy in an Active Population

    PubMed Central

    Voight, Michael L.; Robinson, Kevin; Gill, Lance; Griffin, Karen

    2010-01-01

    Context: With the evolution of hip arthroscopy has come an increased recognition of intra-articular hip pathologies and improved techniques for their management. Whereas mechanical problems can often be corrected through surgery, functional deficits must be corrected through the rehabilitation process. Therefore, the evolution of hip arthroscopy has necessitated a progression in hip rehabilitation to ensure optimal postsurgical results. Evidence Acquisition: Literature review was conducted with PubMed, EMBASE, and PEDro (1992 to 2009) with the terms hip, rehabilitation, and physical therapy. Results: Although it is generally accepted that rehabilitation after hip arthroscopy is important, there is limited evidence-based research to support the rehabilitative guidelines. Conclusion: The common goal of hip rehabilitation should remain focused on the return to pain-free function of the hip joint. Outcome data indicate that this goal is being met; however, further data are required to completely validate the long-term success of hip rehabilitation after arthroscopy. PMID:23015942

  20. The 1963 Hip-Hop Machine: Hip-Hop Pedagogy as Composition.

    ERIC Educational Resources Information Center

    Rice, Jeff

    2003-01-01

    Proposes an alternative invention strategy for research-based argumentative writing. Investigates the coincidental usage of the term "whatever" in hip-hop, theory, and composition studies. Presents a "whatever-pedagogy" identified as "hip-hop pedagogy," a writing practice that models itself after digital sampling's…

  1. HIP HOP for HIV Awareness: Using Hip Hop Culture to Promote Community-Level HIV Prevention

    ERIC Educational Resources Information Center

    Hill, Mandy J.; Hallmark, Camden J.; McNeese, Marlene; Blue, Nike; Ross, Michael W.

    2014-01-01

    The goal of this paper was to determine the effectiveness of the HIP HOP for HIV Awareness intervention, an innovative model utilising an exchange of an HIV test for a hip hop concert ticket, in a metropolitan city among African American youth and young adults. A subset of intervention participants participated in standardised testing, sex…

  2. Invariant hip moment pattern while walking with a robotic hip exoskeleton.

    PubMed

    Lewis, Cara L; Ferris, Daniel P

    2011-03-15

    Robotic lower limb exoskeletons hold significant potential for gait assistance and rehabilitation; however, we have a limited understanding of how people adapt to walking with robotic devices. The purpose of this study was to test the hypothesis that people reduce net muscle moments about their joints when robotic assistance is provided. This reduction in muscle moment results in a total joint moment (muscle plus exoskeleton) that is the same as the moment without the robotic assistance despite potential differences in joint angles. To test this hypothesis, eight healthy subjects trained with the robotic hip exoskeleton while walking on a force-measuring treadmill. The exoskeleton provided hip flexion assistance from approximately 33% to 53% of the gait cycle. We calculated the root mean squared difference (RMSD) between the average of data from the last 15 min of the powered condition and the unpowered condition. After completing three 30-min training sessions, the hip exoskeleton provided 27% of the total peak hip flexion moment during gait. Despite this substantial contribution from the exoskeleton, subjects walked with a total hip moment pattern (muscle plus exoskeleton) that was almost identical and more similar to the unpowered condition than the hip angle pattern (hip moment RMSD 0.027, angle RMSD 0.134, p<0.001). The angle and moment RMSD were not different for the knee and ankle joints. These findings support the concept that people adopt walking patterns with similar joint moment patterns despite differences in hip joint angles for a given walking speed.

  3. Total Hip Arthroplasty Using S-ROM Prosthesis for Dysplastic Hip

    PubMed Central

    Moon, Kyoung Ho; Kim, Ryuh Sup; Park, Seung Rim; Lee, Jung Sun; Shin, Sang Hyun

    2011-01-01

    Purpose The purpose of this study was to evaluate the clinical and radiological results of total hip arthroplasty using a proximal modular femoral stem in patients who had secondary coxarthrosis associated with a dysplastic hip. Materials and Methods Forty-two patients (45 hips) with secondary coxarthrosis were evaluated after undergoing primary total hip arthroplasty using an S-ROM proximal modular femoral stem. The average follow-up was 80 months (range: 60 to 96 months). Clinical and radiological assessments were performed based on the Harris hip score and the radiological changes around the prosthesis. Results The average Harris hip score improved from 52.2 points to 88.5 points. All femoral stems showed stable fixation; there were 37 cases by bony ingrowth and 8 cases by stable fibrous ingrowth. Neither osteolysis nor progressive radiolucent lines around the femoral stem were found at the last follow-up. Forty-one hips (91.9%) revealed excellent or good clinical results at the most recent follow-up. Conclusion For advanced secondary coxarthrosis, total hip arthroplasty with the use of the proximal modular femoral stem yielded good mid-term results with respect to the clinical and radiological criteria. PMID:21623609

  4. Total Hip Arthroplasty in a Girdlestone Hip following a Failed Hemiarthroplasty

    PubMed Central

    Purushotham, VJ; Ranganath, BT

    2015-01-01

    Introduction: Girdlestone hip arthroplasty, though described as a salvage procedure for infected hip joints, can also be considered for failed Hemiarthroplasty procedures. The functional results of such Girdlestone hip may not be satisfactory. They may require total hip replacement to improve the quality of life, which are technically challenging. Here we are reporting such a case ina 60 year old male patient, with review of literature. Case Report: A 60 year old male patient underwent cemented bipolar hemiarthroplasty for fracture neck of femur which failed, owing to improper implantation. Subsequently he underwent Girdlestone arthroplasty which resulted in persistent painful hip. He presented to us in this situation, where we successfully converted the Girdlestone arthroplasty to a Total Hip arthroplasty. Conclusion: Improper implantation in Hemiarthroplasty fails subsequently. In such cases Girdlestone arthroplasty may be an option to consider, though it may not give requisite relief to patient in some cases. In such situations total hip arthroplasty procedure, though technically challenging will give stable painless hip to the patient. PMID:27299043

  5. Hip reconstruction osteotomy by Ilizarov method as a salvage option for abnormal hip joints.

    PubMed

    Umer, Masood; Rashid, Haroon; Umer, Hafiz Muhammad; Raza, Hasnain

    2014-01-01

    Hip joint instability can be secondary to congenital hip pathologies like developmental dysplasia (DDH) or acquired such as sequel of infective or neoplastic process. An unstable hip is usually associated with loss of bone from the proximal femur, proximal migration of the femur, lower-extremity length discrepancy, abnormal gait, and pain. In this case series of 37 patients coming to our institution between May 2005 and December 2011, we report our results in treatment of unstable hip joint by hip reconstruction osteotomy using the Ilizarov method and apparatus. This includes an acute valgus and extension osteotomy of the proximal femur combined with gradual varus and distraction (if required) for realignment and lengthening at a second, more distal, femoral osteotomy. 18 males and 19 females participated in the study. There were 17 patients with DDH, 12 with sequelae of septic arthritis, 2 with tuberculous arthritis, 4 with posttraumatic arthritis, and 2 with focal proximal femoral deficiency. Outcomes were evaluated by using Harris Hip Scoring system. At the mean follow-up of 37 months, Harris Hip Score had significantly improved in all patients. To conclude, illizarov hip reconstruction can successfully improve Trendelenburg's gait. It supports the pelvis and simultaneously restores knee alignment and corrects lower-extremity length discrepancy (LLD).

  6. The influence of the oscillation angle and the neck anteversion of the prosthesis on the cup safe-zone that fulfills the criteria for range of motion in total hip replacements. The required oscillation angle for an acceptable cup safe-zone.

    PubMed

    Yoshimine, Fumihiro

    2005-01-01

    A normal hip joint has more than 120 degrees flexion. The reduced range of motion (ROM) of total hip arthroplast leads to frequent prosthetic impingement, subluxation and dislocation. Prosthetic impingement may be more serious for metal-on-metal and ceramic-on-ceramic total hip prosthesis (THP). A larger oscillation angle of THP (OsA) and proper cup and neck positions make a larger theoretical ROM of a patient's artificial hip joint. But what OsA is required and what range of cup positions is kinetically accepted are not clearly understood. A ROM of more than 120 degrees flexion, 45 degrees internal-rotation at 90 degrees flexion, 30 degrees extension and 40 degrees external-rotation was defined as severe criteria for an acceptable ROM. Theoretical cup safe-zones were created that fulfill the severe criteria of ROM for (OsA=110 degrees , 120 degrees , 135 degrees ) by the mathematical formulas. The size of the cup safe-zone mainly depends on the size of the OsA. There is no cup safe-zone for 110 degrees OsA, an extremely small safe-zone for 120 degrees OsA and an acceptable safe-zone for 135 degrees OsA. Each THP has its own OsA, because OsA is the function of head and neck diameter and cup design. More than 135 degrees OsA enlarges the safe-zone of the prosthetic position, so it extends the acceptable range of error that surgeons cannot avoid completely. However, few THPs with more than 135 degrees OsA are currently clinically available. Both surgeons and manufacturers must realize that OsA is as essential as cup and neck orientations for ROM.

  7. Effects of perioperative factors and hip geometry on hip abductor muscle strength during the first 6 months after anterolateral total hip arthroplasty

    PubMed Central

    Ikeda, Takashi; Jinno, Tetsuya; Aizawa, Junya; Masuda, Tadashi; Hirakawa, Kazuo; Ninomiya, Kazunari; Suzuki, Kouji; Morita, Sadao

    2017-01-01

    [Purpose] The importance and effect of hip joint geometry on hip abductor muscle strength are well known. In addition, other perioperative factors are also known to affect hip abductor muscle strength. This study examined the relative importance of factors affecting hip abductor muscle strength after total hip arthroplasty. [Subjects and Methods] The subjects were 97 females with osteoarthritis scheduled for primary unilateral THA. The following variables were assessed preoperatively and 2 and 6 months after surgery: isometric hip abductor strength, radiographic analysis (Crowe class, postoperative femoral offset (FO)), Frenchay Activities Index, compliance rate with home exercise, Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), and demographic data. Factors related to isometric hip abductor muscle strength 2 and 6 months after surgery were examined. [Results] Significant factors related to isometric hip abductor muscle strength at 2 and 6 months after surgery were, in extraction order: 1. isometric hip abductor muscle strength in the preoperative period; 2. BMI; and 3. the JHEQ mental score at 2 and 6 months after surgery. [Conclusion] Preoperative factors and postoperative mental status were related to postoperative isometric hip abductor strength. FO was not extracted as a significant factor related to postoperative isomeric hip abductor strength. PMID:28265161

  8. Effects of perioperative factors and hip geometry on hip abductor muscle strength during the first 6 months after anterolateral total hip arthroplasty.

    PubMed

    Ikeda, Takashi; Jinno, Tetsuya; Aizawa, Junya; Masuda, Tadashi; Hirakawa, Kazuo; Ninomiya, Kazunari; Suzuki, Kouji; Morita, Sadao

    2017-02-01

    [Purpose] The importance and effect of hip joint geometry on hip abductor muscle strength are well known. In addition, other perioperative factors are also known to affect hip abductor muscle strength. This study examined the relative importance of factors affecting hip abductor muscle strength after total hip arthroplasty. [Subjects and Methods] The subjects were 97 females with osteoarthritis scheduled for primary unilateral THA. The following variables were assessed preoperatively and 2 and 6 months after surgery: isometric hip abductor strength, radiographic analysis (Crowe class, postoperative femoral offset (FO)), Frenchay Activities Index, compliance rate with home exercise, Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), and demographic data. Factors related to isometric hip abductor muscle strength 2 and 6 months after surgery were examined. [Results] Significant factors related to isometric hip abductor muscle strength at 2 and 6 months after surgery were, in extraction order: 1. isometric hip abductor muscle strength in the preoperative period; 2. BMI; and 3. the JHEQ mental score at 2 and 6 months after surgery. [Conclusion] Preoperative factors and postoperative mental status were related to postoperative isometric hip abductor strength. FO was not extracted as a significant factor related to postoperative isomeric hip abductor strength.

  9. Unicompartmental isoelastic resurfacing prosthesis for malignant tumor of the distal radius: A case report with a 3-year follow-up.

    PubMed

    Ichihara, S; Hidalgo-Diaz, J J; Facca, S; Liverneaux, P

    2015-12-01

    We report a case of 74-year-old man in whom a unicompartmental isoelastic resurfacing prosthesis was used to reconstruct the distal radius after en-bloc resection of a malignant tumor. Thirty-nine months after the operation, on a visual analogic scale, pain score was 0/10 and range of motion was 25° of flexion, 5° of extension, 70° of pronation, 45° of supination, 20° of radial deviation, and 30° of ulnar deviation. The Quick DASH functional score was 72.72/100. With radiographic finding, the prosthesis was well-aligned, with no evidence of loosening but with slightly implant conflict with the lunate. This case report indicates that unicompartmental isoelastic resurfacing prosthesis seems a simple and reliable technique for distal radius reconstruction after en-bloc resection of malignant tumor.

  10. Imaging of the hip: a systematic approach to the young adult hip

    PubMed Central

    Chiamil, Sara Muñoz; Abarca, Claudia Astudillo

    2016-01-01

    Summary Background Great advances in knowledge and understanding of the biomechanics of the hip, both in arthroscopic procedures and imaging techniques, have expanded and improved the diagnosis of pathologies of the young adult hip. The anatomy of the hip joint is complex due to its morphology and orientation. The inter-pretation of the images requires deep knowledge of the osseous and soft tissue anatomy: muscles, tendons, ligaments, vessels and nerves. There are multiple imaging tools. Diagnostic techniques have different utilities and often are complementary. Methods In this article the various diagnostic imaging techniques for evaluation of hip pathologies are discussed, their indications and usefulness, with emphasis on those resolved arthroscopically. Conclusion Young adult hip disorders are increasingly diagnosed and treated as arthroscopic procedures improved. Radiology is a fundamental contribution in the diagnostic process. Plain radiography (X-ray) is always the initial examination. Level of evidence V. PMID:28066731

  11. Two-Stage Cementless Revision Total Hip Arthroplasty for Infected Primary Hip Arthroplasties.

    PubMed

    Camurcu, Yalkin; Sofu, Hakan; Buyuk, Abdul Fettah; Gursu, Sarper; Kaygusuz, Mehmet Akif; Sahin, Vedat

    2015-09-01

    The main purpose of the present study was to analyze the clinical features, the most common infective agents, and the results of two-stage total hip revision using a teicoplanin-impregnated spacer. Between January 2005 and July 2011, 41 patients were included. At the clinical status analysis, physical examination was performed, Harris hip score was noted, isolated microorganisms were recorded, and the radiographic evaluation was performed. The mean Harris hip score was improved from 38.9 ± 9.6 points to 81.8 ± 5.8 points (P<0.05). Infection was eradicated in 39 hips. Radiographic evidence of stability was noted in 37 acetabular revision components, and all femoral stems. Two-stage revision of the infected primary hip arthroplasty is a time-consuming but a reliable procedure with high rates of success.

  12. The World Hip Trauma Evaluation Study 3

    PubMed Central

    Parsons, N.; Achten, J.; Griffin, X. L.; Costa, M. L.; Reed, M. R.

    2016-01-01

    Background Approximately half of all hip fractures are displaced intracapsular fractures. The standard treatment for these fractures is either hemiarthroplasty or total hip arthroplasty. The recent National Institute for Health and Care Excellence (NICE) guidance on hip fracture management recommends the use of ‘proven’ cemented stem arthroplasty with an Orthopaedic Device Evaluation Panel (ODEP) rating of at least 3B (97% survival at three years). The Thompsons prosthesis is currently lacking an ODEP rating despite over 50 years of clinical use, likely due to the paucity of implant survival data. Nationally, adherence to these guidelines is varied as there is debate as to which prosthesis optimises patient outcomes. Design This study design is a multi-centre, multi-surgeon, parallel, two arm, standard-of-care pragmatic randomised controlled trial. It will be embedded within the WHiTE Comprehensive Cohort Study (ISRCTN63982700). The main analysis is a two-way equivalence comparison between Hemi-Thompson and Hemi-Exeter polished taper with Unitrax head. Secondary outcomes will include radiological leg length discrepancy measured as per Bidwai and Willett, mortality, re-operation rate and indication for re-operation, length of index hospital stay and revision at four months. This study will be supplemented by the NHFD (National Hip Fracture Database) dataset. Discussion Evidence on the optimum choice of prosthesis for hemiarthroplasty of the hip is lacking. National guidance is currently based on expert opinion rather than empirical evidence. The incidence of hip fracture is likely to continue to increase and providing high quality evidence on the optimum Cite this article: A. L. Sims. The World Hip Trauma Evaluation Study 3: Hemiarthroplasty Evaluation by Multicentre Investigation – WHITE 3: HEMI – An Abridged Protocol. Bone Joint Res 2016;5:18–25. DOI: 10.1302/2046-3758.51.2000473 PMID:26825319

  13. Hip arthroscopy in children and adolescents.

    PubMed

    Kocher, Mininder S; Kim, Young-Jo; Millis, Michael B; Mandiga, Rahul; Siparsky, Patrick; Micheli, Lyle J; Kasser, James R

    2005-01-01

    Hip arthroscopy has become an established procedure for certain indications in adults, but experience in children and adolescents has been more limited. The purpose of this study is to report the early-term results of hip arthroscopy in children and adolescents. A consecutive case series of 54 hip arthroscopies in 42 patients 18 years old and younger over a 3-year period at a tertiary-care children's hospital with a minimum of 1 year of follow-up was reviewed. Patients were assessed with the modified Harris hip score (HHS) before and after surgery. Overall results and results by common diagnoses were analyzed. Indications for surgery included isolated labral tear (n = 30), Perthes disease (n = 8), hip dysplasia with labral tear after prior periacetabular osteotomy (n = 8), inflammatory arthritis (n = 3), spondyloepiphyseal dysplasia (n = 2), avascular necrosis (n = 1), slipped capital femoral epiphysis (n = 1), and osteochondral fracture (n = 1). Overall, there was a significant improvement in HHS from 53.1 to 82.9 (P < 0.001), with 83% of patients improved. By diagnosis, significant improvement in HHS was seen for patients with isolated labral tears undergoing labral debridement (before surgery 57.6; after surgery 89.2; P < 0.001), for patients with Perthes disease undergoing chondroplasty and loose body excision (before surgery 49.5; after surgery 80.1; P < 0.001), and for patients with hip dysplasia after prior periacetabular osteotomy undergoing labral debridement (before surgery 51.8; after surgery 79.8; P < 0.001). Complications included transient pudendal nerve palsy (n = 3), instrument breakage (n = 1), and recurrent labral tear (n = 3). Hip arthroscopy in children and adolescents appears to be safe and efficacious for certain indications in the short term.

  14. Accelerated reduction of post-skin-resurfacing erythema and discomfort with a combination of non-thermal blue and near infrared light.

    PubMed

    Trelles, Mario; Elman, Monica; Slatkine, Michael; Harth, Yoram

    2005-06-01

    The prolonged crusting and erythematic phases following chemical and laser skin resurfacing create discomfort and aggravate patients. Depending on the aggressiveness of the procedure, post-procedure erythema may last from three weeks to several months. iClearXL (CureLight Ltd) is a non-contact, non-thermal blue (405-420 nm)/near infrared (850-900 nm) dual-band light source emitting up to 60 J/cm2 on a 30 cm by 30 cm treatment area. The blue component of the light source has been proven to have a significant anti-inflammatory effect, whereas the near infrared component enhances vascular circulation as well as lymphatic drainage in the thin, necrotized papillary layer. Facial skin laser resurfacing was performed on twelve patients. Starting one day after resurfacing, six patients received a daily 20-minute treatment of blue (405-420 nm)/near infrared (850-900 nm) light for six consecutive days, and six control patients were treated with the usual topical care protocol. Twelve days after the procedure, the treated group had a weighted average erythema score of 0.33 as compared to 1.33 in the control group. Two months after the procedure, the treated group had a weighted average erythema score of 0.16 as compared to 0.83 in the control group. Twelve days after the procedure, the treated group had a weighted average discomfort score of 0.33 as compared to 0.83 in the control group. The tested combination of non-thermal blue (405-420 nm)/near infrared (850-900 nm) dual-band light was found to significantly shorten the duration of post-laser-resurfacing erythema and discomfort with no side effects.

  15. Prevention of congenital dislocation of the hip in the newborn.

    PubMed

    Miranda, L; Palomo, J M; Monzonis, J; Marti, V

    1988-01-01

    Routine examination and early treatment of any instability in the hips of newborns has recently been called into question after a period of universal agreement. The hips of 49,937 neonates were prospectively studied by a general hip screening. Every unstable hip--449 in 317 children--was immediately treated with a Von Rosen splint for a 3-month-period. Overall, satisfactory reduction of the incidence of established congenital dislocation of the hip (CDH) was achieved. Risk factors leading to unstable hips (sex, first birth, and breech birth) and the development of CDH (time of stabilization) were considered.

  16. Magnetic resonance imaging of hip joint cartilage and labrum

    PubMed Central

    Zilkens, Christoph; Miese, Falk; Jäger, Marcus; Bittersohl, Bernd; Krauspe, Rüdiger

    2011-01-01

    Hip joint instability and impingement are the most common biomechanical risk factors that put the hip joint at risk to develop premature osteoarthritis. Several surgical procedures like periacetabular osteotomy for hip dysplasia or hip arthroscopy or safe surgical hip dislocation for femoroacetabular impingement aim at restoring the hip anatomy. However, the success of joint preserving surgical procedures is limited by the amount of pre-existing cartilage damage. Biochemically sensitive MRI techniques like delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) might help to monitor the effect of surgical or non-surgical procedures in the effort to halt or even reverse joint damage. PMID:22053256

  17. Outcome, revision rate and indication for revision following resurfacing hemiarthroplasty for osteoarthritis of the shoulder: 837 operations reported to the Danish Shoulder Arthroplasty Registry.

    PubMed

    Rasmussen, J V; Polk, A; Sorensen, A K; Olsen, B S; Brorson, S

    2014-04-01

    In this study, we evaluated patient-reported outcomes, the rate of revision and the indications for revision following resurfacing hemiarthroplasty of the shoulder in patients with osteoarthritis. All patients with osteoarthritis who underwent primary resurfacing hemiarthroplasty and reported to the Danish Shoulder Arthroplasty Registry (DSR), between January 2006 and December 2010 were included. There were 772 patients (837 arthroplasties) in the study. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index was used to evaluate patient-reported outcome 12 months (10 to 14) post-operatively. The rates of revision were calculated from the revisions reported to the DSR up to December 2011 and by checking deaths with the Danish National Register of Persons. A complete questionnaire was returned by 688 patients (82.2%). The mean WOOS was 67 (0 to 100). A total of 63 hemiarthroplasties (7.5%) required revision; the cumulative five-year rate of revision was 9.9%. Patients aged < 55 years had a statistically significant inferior WOOS score, which exceeded the minimal clinically important difference, compared with older patients (mean difference 14.2 (8.8; 95% CI 19.6; p < 0.001), but with no increased risk of revision. There was no significant difference in the mean WOOS or the risk of revision between designs of resurfacing hemiarthroplasty.

  18. Cystic lesion around the hip joint

    PubMed Central

    Yukata, Kiminori; Nakai, Sho; Goto, Tomohiro; Ikeda, Yuichi; Shimaoka, Yasunori; Yamanaka, Issei; Sairyo, Koichi; Hamawaki, Jun-ichi

    2015-01-01

    This article presents a narrative review of cystic lesions around the hip and primarily consists of 5 sections: Radiological examination, prevalence, pathogenesis, symptoms, and treatment. Cystic lesions around the hip are usually asymptomatic but may be observed incidentally on imaging examinations, such as computed tomography and magnetic resonance imaging. Some cysts may enlarge because of various pathological factors, such as trauma, osteoarthritis, rheumatoid arthritis, or total hip arthroplasty (THA), and may become symptomatic because of compression of surrounding structures, including the femoral, obturator, or sciatic nerves, external iliac or common femoral artery, femoral or external iliac vein, sigmoid colon, cecum, small bowel, ureters, and bladder. Treatment for symptomatic cystic lesions around the hip joint includes rest, nonsteroidal anti-inflammatory drug administration, needle aspiration, and surgical excision. Furthermore, when these cysts are associated with osteoarthritis, rheumatoid arthritis, and THA, primary or revision THA surgery will be necessary concurrent with cyst excision. Knowledge of the characteristic clinical appearance of cystic masses around the hip will be useful for determining specific diagnoses and treatments. PMID:26495246

  19. Trajectories of depressive symptoms after hip fracture

    PubMed Central

    Cristancho, P.; Lenze, E. J.; Avidan, M. S.; Rawson, K. S.

    2016-01-01

    Background Hip fracture is often complicated by depressive symptoms in older adults. We sought to characterize trajectories of depressive symptoms arising after hip fracture and examine their relationship with functional outcomes and walking ability. We also investigated clinical and psychosocial predictors of these trajectories. Method We enrolled 482 inpatients, aged ≥60 years, who were admitted for hip fracture repair at eight St Louis, MO area hospitals between 2008 and 2012. Participants with current depression diagnosis and/or notable cognitive impairment were excluded. Depressive symptoms and functional recovery were assessed with the Montgomery–Asberg Depression Rating Scale and Functional Recovery Score, respectively, for 52 weeks after fracture. Health, cognitive, and psychosocial variables were gathered at baseline. We modeled depressive symptoms using group-based trajectory analysis and subsequently identified correlates of trajectory group membership. Results Three trajectories emerged according to the course of depressive symptoms, which we termed ‘resilient’, ‘distressed’, and ‘depressed’. The depressed trajectory (10% of participants) experienced a persistently high level of depressive symptoms and a slower time to recover mobility than the other trajectory groups. Stressful life events prior to the fracture, current smoking, higher anxiety, less social support, antidepressant use, past depression, and type of implant predicted membership of the depressed trajectory. Conclusions Depressive symptoms arising after hip fracture are associated with poorer functional status. Clinical and psychosocial variables predicted membership of the depression trajectory. Early identification and intervention of patients in a depressive trajectory may improve functional outcomes after hip fracture. PMID:27032698

  20. Current Concepts in Hip Preservation Surgery

    PubMed Central

    Adler, Kelly L.; Cook, P. Christopher; Geisler, Paul R.; Yen, Yi-Meng; Giordano, Brian D.

    2016-01-01

    Context: Successful treatment of nonarthritic hip pain in young athletic individuals remains a challenge. A growing fund of clinical knowledge has paralleled technical innovations that have enabled hip preservation surgeons to address a multitude of structural variations of the proximal femur and acetabulum and concomitant intra-articular joint pathology. Often, a combination of open and arthroscopic techniques are necessary to treat more complex pathomorphologies. Peri- and postoperative recovery after such procedures can pose a substantial challenge to the patient, and a dedicated, thoughtful approach may reduce setbacks, limit morbidity, and help optimize functional outcomes. Evidence Acquisition: PubMed and CINAHL databases were searched to identify relevant scientific and review articles through December 2014 using the search terms hip preservation, labrum, surgical dislocation, femoroacetabular impingement, postoperative rehabilitation, peri-acetabular osteotomy, and rotational osteotomy. Reference lists of included articles were reviewed to locate additional references of interest. Study Design: Clinical review. Level of Evidence: Level 4. Results: Hip preservation procedures and appropriate rehabilitation have allowed individuals to return to a physically active lifestyle. Conclusion: Effective postoperative rehabilitation must consider modifications and precautions specific to the particular surgical techniques used. Proper postoperative rehabilitation after hip preservation surgery may help optimize functional recovery and maximize clinical success and patient satisfaction. PMID:26733593

  1. Problems With Large Joints: Hip Conditions.

    PubMed

    Goerl, Kyle

    2016-07-01

    Common overuse injuries of the hip include greater trochanteric pain syndrome (GTPS) and coxa saltans (ie, snapping hip). GTPS, previously called trochanteric bursitis, is a regional chronic pain syndrome. Etiologies include gluteal tendinitis or tendinosis, gluteal muscle or tendon tears, bursitis, meralgia paresthetica, iliotibial band disorders, and referred osteoarthritis pain. Treatment typically consists of activity modification and physical therapy (PT). Snapping hip can have multiple etiologies. Extra-articular etiologies include iliotibial band syndrome and iliopsoas snapping. Patients typically are treated with activity modification and PT. Intra-articular snapping usually is the result of chondral or acetabular labral injuries, and may require surgical intervention. Femoroacetabular impingement is an emerging etiology of hip pain. Patients commonly report anterior hip or groin pain with insidious onset. It results from cam-type impingement from an irregular shape of the femoral head-neck junction, pincer-type impingement from the acetabulum, or mixed-type impingement resulting from a combination of abnormalities. This atypical morphology can lead to labral tears or chondral injuries, which may manifest as painful clicking or popping. Treatments range from conservative, including activity modification, anti-inflammatory drugs, and PT, to surgical correction of the atypical morphology and addressing labral or chondral damage when present.

  2. Computer-assisted orthopaedic surgery and robotic surgery in total hip arthroplasty.

    PubMed

    Sugano, Nobuhiko

    2013-03-01

    . Fluoroscopic navigation is good for trauma and spine surgeries, but its benefits are limited in the hip and knee reconstruction surgeries. Several studies have shown that the cup alignment with navigation is more precise than that of the conventional mechanical instruments, and that it is useful for optimizing limb length, range of motion, and stability. Recently, patient specific templates, based on CT images, have attracted attention and some early reports on cup placement, and resurfacing showed improved accuracy of the procedures. These various CAOS systems have pros and cons. Nonetheless, CAOS is a useful tool to help surgeons perform accurately what surgeons want to do in order to better achieve their clinical objectives. Thus, it is important that the surgeon fully understands what he or she should be trying to achieve in THA for each patient.

  3. Effects of preoperative physiotherapy in hip osteoarthritis patients awaiting total hip replacement

    PubMed Central

    Czyżewska, Anna; Walesiak, Katarzyna; Krawczak, Karolina; Cabaj, Dominika; Górecki, Andrzej

    2014-01-01

    Introduction The World Health Organization (WHO) claimed osteoarthritis as a civilization-related disease. The effectiveness of preoperative physiotherapy among patients suffering hip osteoarthritis (OA) at the end of their conservative treatment is rarely described in the literature. The aim of this study was to assess the quality of life and musculoskeletal health status of patients who received preoperative physiotherapy before total hip replacement (THR) surgery within a year prior to admission for a scheduled THR and those who did not. Material and methods Forty-five patients, admitted to the Department of Orthopaedics and Traumatology of Locomotor System for elective total hip replacement surgery, were recruited for this study. The assessment consisted of a detailed interview using various questionnaires: the Harris Hip Score (HHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the 36-Item Short Form Health Survey (SF-36), and the Hip disability and Osteoarthritis Outcome Score (HOOS), as well as physical examination. Patients were assigned to groups based on their attendance of preoperative physiotherapy within a year prior to surgery. Results Among patients who received preoperative physiotherapy a significant improvement was found for pain, daily functioning, vitality, psychological health, social life, and (active and passive) internal rotation (p < 0.05). Conclusions Patients are not routinely referred to physiotherapy within a year before total hip replacement surgery. This study confirmed that pre-operative physiotherapy may have a positive influence on selected musculoskeletal system status indicators and quality of life in hip osteoarthritis patients awaiting surgery. PMID:25395951

  4. Resolving controversies in hip fracture care: the need for large collaborative trials in hip fractures.

    PubMed

    Bhandari, Mohit; Sprague, Sheila; Schemitsch, Emil H

    2009-07-01

    Hip fractures are a significant cause of morbidity and mortality worldwide and the burden of disability associated with hip fractures globally vindicate the need for high-quality research to advance the care of patients with hip fractures. Historically, large, multi-centre randomized controlled trials have been rare in the orthopaedic trauma literature. Similar to other medical specialties, orthopaedic research is currently undergoing a paradigm shift from single centre initiatives to larger collaborative groups. This is evident with the establishment of several collaborative groups in Canada, in the United States, and in Europe, which has proven that multi-centre trials can be extremely successful in orthopaedic trauma research.Despite ever increasing literature on the topic of his fractures, the optimal treatment of hip fractures remains unknown and controversial. To resolve this controversy large multi-national collaborative randomized controlled trials are required. In 2005, the International Hip Fracture Research Collaborative was officially established following funding from the Canadian Institute of Health Research International Opportunity Program with the mandate of resolving controversies in hip fracture management. This manuscript will describe the need, the information, the organization, and the accomplishments to date of the International Hip Fracture Research Collaborative.

  5. Two-stage revision of hip prosthesis infection using a hip spacer with stabilising proximal cementation.

    PubMed

    Gil Gonzalez, Sergi; Marqués López, Fernando; Rigol Ramon, Pau; Mestre Cortadellas, Carlos; Cáceres Palou, Enric; León García, Alfonso

    2010-01-01

    Two-stage revision hip arthroplasty for infection using an antibiotic-loaded cement spacer has been used frequently with good results. However, spacer instability is also frequent. Proximal cementation of the spacer could avoid spacer dislocation. We retrospectively assessed 35 patients in whom a 2-stage revision hip arthroplasty for infection was carried out using an antibiotic-loaded cement spacer with gentamicin (Spacer-G) in which the spacer was proximally cemented in 16 patients. The mean follow-up was 32 months. We assessed spacer stability and infection elimination. There were 8 spacer dislocations (22.9%), 5 in hips without proximal cementation and 2 in hips with proximal cementation (p>0.05). There was no fracture in any hip. Reinfection occurred in 5 hips (14.3%), in 3 with the same microorganism, while 2 had a different microorganism. Our results indicate that the proximal cementation of the spacer prevents its dislocation. Infection was eliminated in 86% of the hips.

  6. Incidence of hip fracture in southeastern Norway

    PubMed Central

    Reikerås, O.

    2006-01-01

    The incidence of hip fracture has been studied extensively, but there is still some doubt whether the age-specific incidence is increasing. The proportion of trochanteric fractures has varied and has also been said to be increasing. We studied data on 1,730 prospectively registered cases from 1998–2003 and computed age- and gender-specific incidence rates for intracapsular and trochanteric fractures. The incidence of hip fracture for women over 50 years was 1,263 and for men 452 per 100,000. The proportion of trochanteric fractures was 38% for women and 41% for men. There was no significant difference in the proportion of trochanteric fractures either between or within the genders, and the proportion did not exceed 50% in any age group. These findings confirm the high incidence of hip fracture in Norway but do not indicate any increase. The proportion of trochanteric fractures also seems to be stable. PMID:17033761

  7. HIP diffusion bonding for gear materials

    SciTech Connect

    Ashworth, M.A.; Jacobs, M.H.; Armstrong, G.R.; Freeman, R.; Rickinson, B.A.; King, S.

    1996-12-31

    Mechanical actuators used on aircraft flight control systems contain highly stressed gears which are made from low alloy steels; either through or surface hardened. Corrosion protection has traditionally been provided by cadmium plating. Conventional stainless steels, even when given surface treatments do not provide the necessary strength, wear and corrosion properties for such gears. HIP processing has been used on cobalt based alloy powders as a new approach to produce gears for mechanical and corrosion testing. The technology has been used both to consolidate the powder and HIP diffusion bond the alloy to conventional stainless steels. The microstructure and properties of the consolidated alloy are presented together with preliminary results from component testing. The diffusion bonding route has produced gears which have much better wear and corrosion resistance than conventional steel gears whilst retaining equivalent fatigue properties. The economics of the process are discussed together with the concept of using the HIP process to shape as well as consolidate the material.

  8. Iliopsoas bursitis following total hip replacement.

    PubMed

    Cheung, Y M; Gupte, C M; Beverly, M J

    2004-12-01

    We report the imaging features of a 52-year-old man presenting with a groin mass and gross lower limb oedema secondary to venous occlusion by massive cystic enlargement of the iliopsoas bursa 4 years after uncemented primary total hip replacement. Ultrasonography of the groin mass demonstrated a large cystic lesion extending into the pelvis. CT showed displacement of the external iliac vessels with venous compression. Bursography showed the bursa's margins and no communication with the hip joint. Diagnostic aspiration excluded infection, but fluid recollection occurred subsequently. Complete resolution of symptoms, including limb swelling, followed surgical excision with no recurrence at the 5-year follow-up. We believe iliopsoas bursitis occurred as a tissue response to polyethylene wear within the prosthetic hip and occurred even in the absence of loosening or a direct communication between bursa and joint.

  9. Bladder tear during revision total hip arthroplasty.

    PubMed

    Grauer, Jonathan N; Halim, Andrea; Keggi, Kristaps J

    2014-08-01

    Total hip arthroplasty (THA) and revision total hip arthroplasty are among the most commonly performed orthopedic procedures. There are many reported complications of THA, but intrapelvic complications are a rare subset. Bladder injuries have infrequently been described in association with this common procedure. We present an unusual case of a bladder tear occurring intraoperatively during a revision THA. It is suspected that the patient's history of multiple prior hip procedures caused adhesions of the bladder to the pelvic floor and predisposed the bladder to injury during acetabular revision. Previous reports of bladder injury relating to THA have described thermal necrosis, component migration, and occasional direct perforation. There are no prior case reports describing bladder tears related to adhesions occurring intraoperatively during revision THA. This case report highlights the importance of surgeon awareness of an unusual complication. In this case, intraoperative and postoperative recognition of a hematuria diagnosis led to the appropriate treatment, and this patient had an acceptable outcome.

  10. Lesion of the hip abductor mechanism

    PubMed Central

    Caviglia, Horacio; Cambiaggi, Guillermo; Vattani, Nosrat; Landro, María Eulalia; Galatro, Gustavo

    2016-01-01

    Introduction: The disruption of the abductor muscles of the hip after hip revision surgery often causes limping, pain, and instability of the implant. The purpose of our paper is to describe a mesh technique to repair hip abductor mechanism injuries after hip revision. Patients and methods: Forty-six patients with hip abductor damage after prosthetic revision were treated. Inclusion criteria were: patients presenting with prosthetic loosening, complaint of pain, and with a positive Trendelenburg sign due to deficient abductor muscle mechanisms. Thirty-one were women (67.39%) with an average age of 64 years (34–82 years). The number of previous revision surgeries was three (two to seven). The Merle d’Aubigné score and variants before and after treatment were also reported. Results: In the postoperative follow-up after hip revision with the mesh technique, the Merle d’Aubigné score improved and the Trendelenburg sign was negative in 78.3% of the patients (p < 0.001). Also, the Trendelenburg test with the knee flexed was negative in 60.9% (p < 0.001) and the stair-climbing test was negative in 60.9% of cases (p < 0.001). The gluteus medius test in the lateral position was negative in 52.2% of patients, and in the lateral position with the knee flexed it was negative in 47.8% of patients (p < 0.001). Discussion: Repair of the abductor mechanism with the mesh technique has proven effective for both partial and total lesions. PMID:27382925

  11. Epidemiology of hip fractures in Okinawa, Japan.

    PubMed

    Arakaki, Harumi; Owan, Ichiro; Kudoh, Hirohisa; Horizono, Hidehiro; Arakaki, Kaoru; Ikema, Yasunari; Shinjo, Hirotaka; Hayashi, Kaori; Kanaya, Fuminori

    2011-05-01

    This study investigated the current incidence of hip fractures in Okinawa prefecture and compared the data with those obtained in our previous study, which was conducted using similar methods in 1987/1988. All patients, aged 50 years or older and residing in Okinawa, admitted to Okinawa hospitals in 2004 for a fresh hip fracture were identified from hospital registries. Details were obtained from the medical records and radiographs of all patients and classified according to fracture type (cervical or trochanteric), age, sex, and fracture location. Subtrochanteric fractures and pathological fractures were excluded. A total of 1,349 patients (242 men and 1,107 women) were admitted for a fresh hip fracture in 2004. Their average age was 76.9 years for men and 82.4 years for women. There were 671 cervical fractures, 654 trochanteric fractures, and 24 unclassified proximal femoral fractures. Comparing the data from 1987/1988 to those from 2004, the total number of hip fractures increased by 188%, from 469 to 1,349. The age-adjusted incidence rates per 100,000, standardized to the 2000 US population, were 75.7 and 296.1 in 1987/1988 and 123.6 and 420 in 2004 for men and women, respectively. The incidence rates in all age groups (at 5-year intervals) were higher in 2004 than in 1987/1988, indicating that people 50 years of age or older became more susceptible to hip fractures. Accordingly, the accretion of the hip fracture incidence rate was greater than that which could be explained purely by changes in population size and structure.

  12. Eastern portal, looking W. Note hipped roof covered with wood ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Eastern portal, looking W. Note hipped roof covered with wood shingles, added in 1993. The hipped roof is unique in U.S. covered bridges. - Doe River Bridge, Spanning Doe River, Third Avenue, Elizabethton, Carter County, TN

  13. Hip Fracture's Link to Early Death May Last Years

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_163802.html Hip Fracture's Link to Early Death May Last Years People ... HealthDay News) -- Older people who suffer a hip fracture face a much higher risk of death soon ...

  14. Effects of Neuromuscular Reeducation on Hip Mechanics and Functional Performance in Patients after Total Hip Arthroplasty: A Case Series

    PubMed Central

    Judd, Dana L.; Winters, Joshua D.; Stevens-Lapsley, Jennifer E.; Christiansen, Cory L.

    2016-01-01

    Background Following total hip arthroplasty, patients demonstrate compensatory movement strategies during activities of daily living such as walking and stair climbing. Movement compensations are important markers of functional decline in older adults and are related to poor functional capacity. Despite increased utilization of hip arthroplasty, persistent movement compensation, and functional performance deficits, no consensus on postoperative rehabilitation exists. Neuromuscular reeducation techniques offer a strategy to improve movement quality by emphasizing hip abductor performance and pelvic stability. This case series illustrates changes in movement strategy around the hip in response to targeted neuromuscular reeducation techniques after hip arthroplasty. Methods Five participants received an 8-week exercise program following total hip arthroplasty, emphasizing targeted neuromuscular reeducation techniques hallmarked by specific, weight-bearing exercise to improve hip abductor performance and pelvic stability. Five additional participants were supervised and followed for comparison. Findings Participants in the neuromuscular reeducation program improved their internal hip abductor moments and vertical ground reaction forces during walking and stair climbing. They also improved their functional performance and hip abductor strength outcomes. Interpretation Targeted neuromuscular reeducation techniques after total hip arthroplasty provided a positive effect on biomechanical outcomes, functional performance, and muscle strength. Through focused use of the hip abductor muscles, increased internal hip abductor moments were observed. This intervention potentially promotes pelvic stability, and may contribute to improved performance on tasks such as stair climbing, fast walking, and balance. The results suggest that neuromuscular reeducation offers a unique effect on movement strategy and function for patients following total hip arthroplasty. PMID:26802531

  15. [Rapidly vanishing hip--a mystery].

    PubMed

    Keren, Yaniv; Sigal, Amit; Greental, Arnan; Vlodavsky, Euvgeni; Soudry, Michael; Militianu, Daniela

    2013-01-01

    Rapidly destructive hip disease is a rare condition, the cause of which is yet to be clarified, and is described in the literature by scant case reports. The disease was first described by Forestier in 1957, and since then many names have been proposed to describe the rapid vanishing of the femoral head, and occasionally the acetabulum. This condition initially represents as acute hip pain, and rapidly progresses to complete vanishing of the proximal femur, within a few months. We briefly discuss the literature regarding this phenomenon, and describe a case of a female patient who suffered from complete disappearance of the femoral head within 9 weeks.

  16. [Imaging of chronic hip pain in adults].

    PubMed

    Chevrot, A; Drapé, J; Godefroy, D; Dupont, A

    2000-03-01

    Adult hip pathologies are mainly represented by the degenerative disease, so called "osteoarthrosis, or more precisely coxarthrosis". The means of imaging are exposed, according to their specific value: X Rays (measurement of the characteristic angles of the adult hip), Arthrography, CT Scanner, Arthro-CT Scanner, MRI, Bone Scintigraphy, Ultrasonography. Clinical findings differentiate a mechanical syndrome and an inflammatory syndrome. The coxarthrosis is the most frequent, under two forms: primary (idiopathic) coxarthrosis and secondary coxarthrosis. Primary (idiopathic) coxarthrosis has a localised narrowing of the joint space, osteophyte formation, subchondral sclerosis, cyst formation. The destruction progresses slowly, in 10 to 15 years leading to a complete destruction. Bilaterality is frequent. it is treated with total hip prosthesis. There is a rapid form (1 to 2 years) (Postel's Disease). Secondary coxarthrosis occurs after architectural vice, chondral diseases, lack of balance between the size of the head and the acetabulum as in the case of previous fracture or dislocation, avascular bone necrosis of the head of the femur, Paget's disease. Calcium pyrophosphate Deposition disease (CPPD) involves mostly aged women, and also leads to cox-arthrosis. Avascular bone necrosis of the head of the femur involves young adults. Bilateral involvement are frequent. MRI is the most sensitive and the most specific means of early diagnosis, The area of bone necrosis appears as well defined modifications of the upper head of the femur, precisely surrounded by a low signal intensity line on both Ti and T2 weighted imaging. MRI shows articular effusion, bone marrow edema. Scintigraphy gives early findings which are a characteristic, but non specific, hot spot. CT scanner is used for hip destruction evaluation. o Algodystrophy: transient osteoporosis of the hip has a cyclic course, lasting 3 to 9 months. MRI shows an inflammatory pattern in the area of the process(dark in

  17. [Gait Analysis in Patients with Hip Disorders].

    PubMed

    Urbášek, K; Poul, J

    2016-01-01

    Recent studies have shown that the evaluation of both conservative and surgical therapy cannot do without gait analysis. Orthopaedic textbooks, with some exceptions, deal in great detail with a thorough clinical examination of the patient but gait assessment is mentioned only marginally. More attention is paid to gait analysis in rehabilitation medicine. Motion and gait analysis laboratories equipped with optoelectronic cameras and force platforms were first developed for cerebral palsy children. Recently, several studies have been published on the use of these methods in disorders of hip and knee joints or spine diseases. Key words: gait analysis, hip joint.

  18. Bilateral traumatic hip dislocation associated with sacro-iliac dislocation.

    PubMed

    Galois, L; Meuley, E; Pfeffer, F; Mainard, D; Delagoutte, J P

    We report a rare injury in an 18-year-old woman who sustained posterior bilateral hip dislocation with sacro-iliac dislocation after a high energy motor vehicle accident. She was treated by closed reduction and skeletal traction. Bilateral traumatic hip dislocation is an uncommon occurrence. Rarer still is bilateral traumatic hip dislocation associated with sacro-iliac dislocation because it combines two different mechanisms of trauma. (Hip International 2002; 1: 47-9).

  19. Preliminary results after reconstruction of bony defects of the proximal humerus with an allograft-resurfacing composite.

    PubMed

    Ruggieri, P; Mavrogenis, A F; Guerra, G; Mercuri, M

    2011-08-01

    We retrospectively studied 14 patients with proximal and diaphyseal tumours and disappearing bone (Gorham's) disease of the humerus treated with wide resection and reconstruction using an allograft-resurfacing composite (ARC). There were ten women and four men, with a mean age of 35 years (8 to 69). At a mean follow-up of 25 months (10 to 89), two patients had a fracture of the allograft. In one of these it was revised with a similar ARC and in the other with an intercalary prosthesis. A further patient had an infection and a fracture of the allograft that was revised with a megaprosthesis. In all patients with an ARC, healing of the ARC-host bone interface was observed. One patient had failure of the locking mechanism of the total elbow replacement. The mean post-operative Musculoskeletal Tumor Society score for the upper extremity was 77% (46.7% to 86.7%), which represents good and excellent results; one patient had a poor result (46.7%). In the short term ARC effectively relieves pain and restores shoulder function in patients with wide resection of the proximal humerus. Fracture and infection remain significant complications.

  20. Humanization of an anti-human TNF-alpha antibody by variable region resurfacing with the aid of molecular modeling.

    PubMed

    Zhang, Wei; Feng, Jiannan; Li, Yan; Guo, Ning; Shen, Beifen

    2005-08-01

    The murine monoclonal antibody Z12 is of therapeutic interest for its neutralizing biological activity against human tumor necrosis factor-alpha (hTNF-alpha). We attempted to humanize Z12 with variable domain resurfacing guided by computer modeling. First, the genes of heavy and light chain variable region (VH, VL) of Z12 were cloned and the whole three-dimensional structure of Fv fragment was constructed by using homology-based modeling and molecular docking methods. Then the complex model of Fv interacting with hTNF-alpha whose crystal structure derived from PDB database was gained with computer-guided docking program. Based on this model, a humanized version was designed. The humanized Fab antibody was constructed, expressed and purified in the pComb3H vector system and it showed unaltered binding affinity to the antigen as determined by ELISA and atomic force microscopy (AFM). The method described here can be used to humanize other anti-hTNF-alpha antibodies.