Search

Hugo Bothorel,1 Anthony Pernoud,1 Panayiotis Christofilopoulos2 1Research Department, la Tour Hospital, Geneva, Switzerland; 2Department of Orthopaedics and Trauma Surgery, La Tour Hospital, Geneva, SwitzerlandCorrespondence: Anthony Pernoud, Tel +41 22 719 78 74, Email Anthony.pernoud@latour.chPurpose: The objective of this study was to develop a cross-cultural adaptation and translation into French of the original Harris Hip Score (HHS) and the modified Harris Hip Score (mHHS).Patients and Methods: The translation and cultural-adaptation of the questionnaire were performed following a 10-step process as recommended by the International Society for Pharmacoeconomics and Outcomes Research (ISPOR). During the cognitive debriefing, each item of the questionnaire has been rated between 1 and 10 according to the comprehension level of 8 patients who underwent total hip arthroplasty.Results: The cross-cultural adaptation process required the modification of the walking distance item by converting the number of blocks into meters but also in walking time (minutes). All the different steps have been performed without any other important changes on the translated questionnaire which has been found highly understandable by interviewed patients (9.6 ± 1.1).Conclusion: This study successfully reports the French version development of the original HHS (HHS-Fr) and its modified patient-reported version (mHHS-Fr), thereby providing to clinicians a standardised version for the evaluation of French-speaking patients suffering from hip osteoarthritis. Keywords: hip, PROM, patient-reported outcome measure, osteoarthritis, French

Bisphenol-A (BPA; 2,2-bis(4-hydroxyphenyl)propane) is a monomer used primarily in the production of polycarbonate and epoxy resins that has been reported to have estrogenic activity. The biodegradability of BPA has been previously investigated in several studies designed to simulate surface waters and biological wastewater treatment systems. However, there is little information available about the phytoremediation of groundwater contaminated with BPA. Halophytic species are of special interest for phytoremediation research since these plants are naturally better adapted to cope with environmental stress. Therefore, in the present paper BPA degradation dynamics have been investigated experimentally and through modeling of a rhizodegradation pilot, emulating a shallow aquifer, treating BPA contaminated groundwater by the halophyte Juncus acutus. The mathematical model considers rhizodegradation as the main BPA phytodegradation mechanism but takes also into account BPA removal through plant up-take and hydrolysis. The model calibration has been performed with raw data from two experimental runs of the pilot unit and the simulations match the experimental data for both runs sufficiently well. [ABSTRACT FROM AUTHOR]

Abstract: Relative risk of impingement and joint instability during sexual activities after total hip arthroplasty (THA) has never been objectively investigated. Hip range of motion necessary to perform sexual positions is unknown. A motion capture study with two volunteers was performed. 12 common sexual positions were captured and relevant hip joint kinematics calculated. The recorded data were applied to prosthetic hip 3D models to evaluate impingement and joint instability during motion. To explore the effect of acetabular component positioning, nine acetabular cup positions were tested. Four sexual positions for women requiring intensive flexion (> 95°) caused prosthetic impingements (associated with posterior instability) at 6 cup positions. Bony impingements (associated with anterior instability) occurred during one sexual position for men requiring high degree of external rotation (> 40°) combined with extension and adduction at all cup positions. This study hence indicates that some sexual positions could be potentially at risk after THA, particularly for women. [Copyright &y& Elsevier]

Background: Little information is available on the results of the different stabilization techniques described for treatment of acute acromioclavicular (AC) joint injuries. Additionally, no studies have analyzed isometric performance of the shoulder after AC stabilization. The objective of our study was to present functional outcome including isokinetic testing and radiographic evaluation of patients treated with stabilization of AC joint dislocations. Patients and methods: Thirty-seven patients with acute type III to V AC joint disruption underwent open coracoclavicular (CC) and AC stabilization with nonabsorbable sutures. Results: The mean follow-up was 4.5 ± 2.5 years (range, 2-10.5). The mean Constant score (CS) was 96. There were 34 (91.9%) excellent results, 1 good (2.7%), 1 satisfactory (2.7%), and 1 fair (2.7%). The disabilities of the arm, shoulder, and hand (DASH) questionnaire revealed good overall subjective evaluation with a mean of 7 points. The mean visual analog scale (VAS) pain score was 0.8. Patients with a CC distance <5 mm, or an anterosuperior AC reduction less than 50%, showed significantly better results in CS and DASH score in comparison to patients with a subluxated AC joint (P < .005). Twenty-two patients agreed to undergo isokinetic evaluation. We were unable to demonstrate any clinically significant difference between the involved and the uninvolved side. Discussion: The described technique of cerclage augmentation offers an attractive alternative in AC joint stabilization, with good to excellent results. In comparison to other techniques, there were no complications related to any implants, no graft donor site morbidity, or need for implant removal. [ABSTRACT FROM AUTHOR]

Purpose: We describe a combined approach for treatment of a type A aortic dissection with surgical repair of the ascending aorta and transluminal stenting of the descending aorta, therefore minimizing the consequences on the untreated aortic arch and descending aorta. Description: From December 2002 to June 2003, 5 consecutive patients (4 men, 1 woman) suffering from type A aortic dissection were treated with resection of the ascending aorta or aortic hemi-arch. Before the open distal aortic anastomosis the Endofit endovascular graft (Endomed Inc, Phoenix, AZ), was deployed under direct vision distally to the origin of the left subclavian artery. Evaluation: Intraoperative stent graft placement was successful in all patients. There was no hospital mortality. Early results were satisfactory with a completely thrombosed false lumen in 2 patients and a partially thrombosed false lumen in 3 patients, 10 days after operation. Follow-up computed tomographic scan showed a completely thrombosed false lumen in 4 patients and a partially thrombosed false lumen in 1 patient. Conclusions: This study shows that combined surgical and endovascular treatment of acute type A dissection is a feasible option, but further evaluation is necessary. [Copyright &y& Elsevier]

Background: The etiopathogenesis of developmental dysplasia of the hip (DDH) has not been clarified. This systematic review evaluated current literature concerning all known chromosomes, loci, genes, and their polymorphisms that have been associated or not with the prevalence and severity of DDH.Methods: Following the established methodology of Meta-analysis of Observational Studies in Epidemiology guidelines, MEDLINE, EMBASE, and Cochrane Register of Controlled Trials were systematically searched from inception to January 2019.Results: Forty-five studies were finally included. The majority of genetic studies were candidate gene association studies assessing Chinese populations with moderate methodological quality. Among the most frequently studied are the first, third, 12th,17th, and 20th chromosomes. No gene was firmly associated with DDH phenotype. Studies from different populations often report conflicting results on the same single-nucleotide polymorphism (SNP). The SNP rs143384 of GDF5 gene on chromosome 20 demonstrated the most robust relationship with DDH phenotype in association studies. The highest odds of coinheritance in linkage studies have been reported for regions of chromosome 3 and 13. Five SNPs have been associated with the severity of DDH. Animal model studies validating previous human findings provided suggestive evidence of an inducing role of mutations of the GDF5, CX3CR1, and TENM3 genes in DDH etiopathogenesis.Conclusion: DDH is a complex disorder with environmental and genetic causes. However, no firm correlation between genotype and DDH phenotype currently exists. Systematic genome evaluation in studies with larger sample size, better methodological quality, and assessment of DDH patients is necessary to clarify the DDH heredity. The role of next-generation sequencing techniques is promising. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the variations in hip muscles strength following arthroscopy and 6-month rehabilitation in patients treated for femoroacetabular impingement (FAI)., Methods: A retrospective analysis was carried out on a series of patients who were arthroscopically treated for FAI at La Tour Hospital between 2020 and 2022. Bilateral isometric strengths of 8 hip-related muscles (abductors, adductors, hamstrings, quadriceps, extensors, flexors, internal and external rotators) were assessed using a handheld dynamometer before surgery and postoperatively after 6 months of rehabilitation in terms of relative strength changes between time points., Results: A total of 29 patients (aged 26.9 ± 7.1 years, 86% of women) were included. Except for the abductors, which remained of comparable strength than before surgery, a statistically significant ( P < .05) increase in hip muscle strength on the operated side could be noted at 6 postoperative months for hamstrings (9% ± 17%, P  = .041), quadriceps (11% ± 27%, P  = .045), extensors (17% ± 32%, P  = .006), flexors (17% ± 29%, P  = .003), adductors (18% ± 23%, P < .001), and internal rotators (32% ± 36%, P < .001). The proportion of patients who reached a strength level above their preoperative status ranged from 62% (quadriceps) to 86% (adductors and flexors), depending on the muscle studied. The external rotators were the only muscles that remained significantly weakened at 6 months on both operated (-13% ± 26%, P  = .002) and nonoperated (-17% ± 25%, P < .001) sides, with a decrease beyond 15% in almost half of the patients (45% and 48%, respectively)., Conclusions: Arthroscopic treatment followed by 6-month rehabilitation granted to most FAI patients a higher strength level for several hip muscles, except for abductors and external rotators, which remained comparable and weakened, respectively., Level of Evidence: Level IV, therapeutic case series., Competing Interests: The authors report no conflicts of interest in the authorship and publication of this article. Full ICMJE author disclosure forms are available for this article online, as supplementary material., (© 2024 The Authors.)

Hip arthroscopy and surgical hip dislocation (SHD) can be adequate surgical options for patients suffering from femoroacetabular impingement (FAI) syndrome, but there is to date no published data on their impact on hip muscles strength. The purpose of this retrospective study was, therefore, to evaluate it on a consecutive series of 50 FAI patients treated either by arthroscopy (n = 29, aged 27.4 ± 7.5 years, 76% of women) or SHD (n = 21, aged 25.9 ± 6.5 years, 38% of women) at La Tour Hospital between 2020 and 2021. The bilateral isometric strengths of eight hip-related muscles were evaluated before and three months after surgery (halfway through the rehabilitation program). For arthroscopy, a statistically significant (p < 0.05) reduction in hip muscles strength could be noted on the operated hamstrings (1.49 ± 0.43 vs. 1.39 ± 0.38 Nm/kg), flexors (1.88 ± 0.46 vs. 1.73 ± 0.41 Nm/kg), abductors (1.97 ± 0.42 vs. 1.72 ± 0.40 Nm/kg) and external rotators (1.17 ± 0.40 vs. 1.04 ± 0.37 Nm/kg). The abductors were the most affected muscles, with 45% of the patients suffering from a strength reduction ≥15%. The non-operated external rotators were also affected but to a lesser extent (1.21 ± 0.38 vs. 1.10 ± 0.36 Nm/kg). For SHD, a statistically significant strength reduction could be noted on the operated extensors (2.28 ± 0.84 vs. 2.05 ± 0.70 Nm/kg), abductors (1.87 ± 0.49 vs. 1.65 ± 0.41 Nm/kg), quadriceps (2.96 ± 0.92 vs. 2.44 ± 0.89 Nm/kg), external rotators (1.16 ± 0.42 vs. 0.93 ± 0.36 Nm/kg) and internal rotators (1.26 ± 0.38 vs. 0.96 ± 0.30 Nm/kg). The internal rotators were the most affected muscles, with 75% of the patients suffering from a strength reduction ≥15%. To conclude, particular attention should be paid to operated abductors for patients treated by arthroscopy as well as operated internal/external rotators, abductors and quadriceps for those treated by surgical hip dislocation. It reinforces that a rehabilitation method based on isolated muscle reinforcement and functional exercises that goes beyond three postoperative months is needed.

Gluteal tendon tears represent a common but underreported cause of lateral hip pain and dysfunction. In case of conservative management failure, a surgical procedure must be performed to relieve patient symptoms. Current operative treatments, either open or endoscopic, have been however associated with different drawbacks which led to the introduction of the mini-open technique. The aim of this study was to evaluate and report the short-term outcomes of patients operated through the aforementioned surgical technique for gluteus medius (GM) chronic tears. We retrospectively analysed the records of 14 consecutive patients operated at the La Tour hospital by mini-open repair using a double-row technique for full-thickness GM chronic tears. Intra- and post-operative complications were recorded. The pre- and post-operative pain on visual analogue scale (pVAS), modified Harris Hip score (mHHS), abduction strength and gait dysfunction were assessed for all patients. Pre- and post-operative values were compared to evaluate whether improvements were statistically significant and clinically relevant. The study cohort comprised 13 women (93%) and 1 man (3%) aged 62.4 ± 18.0 at index surgery. No intra- or post-operative complications were noted. Compared to pre-operative values, patients reported a significant improvement in mHHS (59.1 ± 7.1 vs 92.7 ± 4.6) and pVAS (7.4 ± 1.0 vs 1.3 ± 1.3) at last follow-up. Patients exhibited a perfect improvement in muscle strength (3.6 ± 0.5 vs 5.0 ± 0.0), and the proportion of patients with a positive Trendelenburg sign decreased from 71% to 0%. Mini-open repair of chronic GM tendon tears using a double-row technique demonstrated excellent clinical and functional outcomes at short follow-up. Level of Evidence : IV., (© The Author(s) 2021. Published by Oxford University Press.)

Background: Limited literature exists concerning the femoral cement mantle quality that can be achieved through an anterior approach in total hip arthroplasty (THA). We radiologically evaluated the quality and thickness of the femoral cement mantle in patients undergoing THA utilizing the direct anterior approach (DAA)., Methods: Immediate postoperative anteroposterior and lateral radiographs of 116 consecutive patients who underwent hybrid or fully cemented THA using the DAA and cemented Quadra-C stem (Medacta, International, SA, Switzerland) were assessed by 2 arthroplasty surgeons blinded to the study. Surgical indications were hip osteoarthritis or subcapital hip fracture. The cement mantle and stem alignment were evaluated using the Barrack classification and Khalily methods, respectively. After calibration of radiographs, the thinnest part of the cement mantle per Gruen zone was recorded. Parameters were compared between obese and nonobese patients., Results: Agreement between raters was substantial for the cement quality in anteroposterior (k = 0.707, P ≤ .001) and moderate for lateral radiographs (k = 0.574, P ≤ 001). The cement mantle was graded A in 39.25%, B in 53.0%, and C in 7.75% of anteroposterior radiographs and similarly for lateral radiographs (40.1% A, 51.75% B, 9.5% C). 93% of stems had neutral alignment. The mean thinnest cement mantle ( P  = .237) and incidence of inadequate cement mantle (<2 mm) per zone ( P  = .431) were comparable between Gruen zones. The cement mantle quality ( P  = .174) and inadequacy ( P > .05) and stem alignment ( P  = .652) were comparable between obese and nonobese patients., Conclusions: DAA enables correct implantation and effective cementation of straight femoral stems. A high-quality cement mantle can be achieved using DAA even in obese patients., (© 2020 The Authors.)

Background and purpose - Revision total hip arthroplasty (THA) is associated with higher dislocation rates than primary THA. We compared the risk of dislocation within 6 months and all-cause re-revision during the whole study period using either the dual-mobility cup or the unipolar cup. Methods - We used a prospective hospital registry-based cohort including all total and cup-only revision THAs performed between 2003 and 2013. The cups used were either dual-mobility or unipolar; the choice was made according to the preference of the surgeon. 316 revision THAs were included. The mean age of the cohort was 69 (25-98) years and 160 THAs (51%) were performed in women. The dual-mobility group (group 1) included 150 THAs (48%) and the mean length of follow-up was 31 (0-128) months. The unipolar group (group 2) included 166 THAs (53%) and the mean length of follow-up was 52 (0-136) months. Results - The incidence of dislocation within 6 months was significantly lower with the dual-mobility cup than with the unipolar cup (2.7% vs. 7.8%). The unadjusted risk ratio (RR) was 0.34 (95% CI: 0.11-1.02) and the adjusted RR was 0.28 (95% CI: 0.09-0.87). The number of patients needed to treat with a dual-mobility cup in order to prevent 1 case of dislocation was 19. The unadjusted incidence rate ratio for all-cause re-revision in the dual-mobility group compared to the unipolar group was 0.6 (95% CI: 0.3-1.4). Interpretation - Use of a dual-mobility rather than a unipolar cup in revision THA reduced the risk of dislocation within 6 months.

Background: Outcomes after total knee (TKA) and hip (THA) arthroplasty are often generalized internationally. Patient-dependent factors and preoperative symptom levels may differ across countries. We compared preoperative patient and clinical characteristics from two large cohorts, one in Switzerland, the other in the US., Methods: Patient characteristics were collected prospectively on all elective primary TKAs and THAs performed at a large Swiss hospital and in a US national sample. Data included age, sex, education level, BMI, diagnosis, medical co-morbidities, PROMs (WOMAC pain/function), global health (SF-12)., Results: Six thousand six hundred eighty primary TKAs (US) and 823 TKAs (Swiss) were evaluated. US vs. Switzerland TKA patients were younger (mean age 67 vs. 72 years.), more obese (BMI ≥30 55% vs. 43%), had higher levels of education, more cardiac disease. Swiss patients had lower preoperative WOMAC pain scores (41 vs. 52) but pre-operative physical disability were comparable. 4,647 primary THAs (US) and 1,023 THAs (Swiss) were evaluated. US vs. Switzerland patients were younger (65 vs. 68 years.), more obese (BMI ≥30: 38% vs. 24%), had higher levels of education, more diabetes. Swiss patients had lower preoperative WOMAC pain scores (40 vs. 48 points). Physical disability was reported comparable, but Swiss patients indicated lower mental health scores., Conclusion: We found substantial differences between US and Swiss cohorts in pre-operative patient characteristics and pain levels, which has potentially important implications for cross-cultural comparison of TKA/THA outcomes. Reports from national registries lack detailed patient information while these data suggest the need for adequate risk adjustment of patient factors.

Background and Purpose: Obesity increases the risk of deep infection after total joint arthroplasty (TJA). Our objective was to determine whether there may be body mass index (BMI) and weight thresholds indicating a higher prosthetic joint infection rate., Patients and Methods: We included all 9,061 primary hip and knee arthroplasties (mean age 70 years, 61% women) performed between March 1996 and December 2013 where the patient had received intravenous cefuroxime (1.5 g) perioperatively. The main exposures of interest were BMI (5 categories: < 24.9, 25-29.9, 30-34.9, 35-39.9, and ≥ 40) and weight (5 categories: < 60, 60-79, 80-99, 100-119, and ≥ 120 kg). Numbers of TJAs according to BMI categories (lowest to highest) were as follows: 2,956, 3,350, 1,908, 633, and 214, respectively. The main outcome was prosthetic joint infection. The mean follow-up time was 6.5 years (0.5-18 years)., Results: 111 prosthetic joint infections were observed: 68 postoperative, 16 hematogenous, and 27 of undetermined cause. Incidence rates were similar in the first 3 BMI categories (< 35), but they were twice as high with BMI 35-39.9 (adjusted HR = 2.1, 95% CI: 1.1-4.3) and 4 times higher with BMI ≥ 40 (adjusted HR = 4.2, 95% CI: 1.8-9.7). Weight ≥ 100 kg was identified as threshold for a significant increase in infection from the early postoperative period onward (adjusted HR = 2.1, 95% CI: 1.3-3.6)., Interpretation: BMI ≥ 35 or weight ≥ 100 kg may serve as a cutoff for higher perioperative dosage of antibiotics.

Femoroacetabular impingements (FAI) are quite frequent among young athletes. An early detection is essential in order to prevent more labral and cartilage damage. Conservative treatment should not focus on forcing the full range of motion but on restoring a good muscle balance around the joint and a better lower limb dynamic stability and control. The patient should be educated to master the end of hip range of motion during his activities. If the outcome is not satisfactory, a surgical treatment is offered. The post-operative treatment protocol is tailored to the type of repair, following several stages, from neuromuscular control to strengthening up to the return to sport. FAI prevention should be more studied in order to protect the hip of the growing athlete.

Different disorders around the hip joint have been diagnosed in athletes of all levels. Pathologies such as femoro-acetabular impingement (FAI) are responsible for lower performance during sports and early onset osteoarthrosis of the hip joint. This article emphasizes on the diagnosis and early treatment of FAI in young athletes. It is meant to raise concern about this relatively new pathology and hence avoid the deleterious results for the hip joint associated with late diagnosis.

In vivo, bone marrow-derived multipotent mesenchymal stromal cells (MSC) have been identified at sites of tumors, suggesting that specific signals mobilize and activate MSC to migrate to areas surrounding tumors. The signals and migratory mechanisms that guide MSC are not well understood. Here, we investigated the migration of human MSC induced by conditioned medium of Huh-7 hepatoma cells (Huh-7 CM). Using a transwell migration system, we showed that human MSC migration was increased in the presence of Huh-7 CM. Using a human cytokine antibody array, we detected increased levels of MIP-1δ and MIP-3α in Huh-7 CM. Recombinant chemokines MIP-1δ and MIP-3α induced MSC migration. Anti-MIP-1δ and anti-MIP-3α antibodies added to Huh-7 CM decreased MSC migration, further suggesting that MIP-1δ and MIP-3α were implicated in the Huh-7 CM-induced MSC migration. By real-time polymerase chain reaction, we observed an absence of chemokine receptors CCR2 and CXCR2 and low expression of CCR1, CCR5, and CCR6 in MSC. Expression of these chemokine receptors was not regulated by Huh-7 CM. Furthermore, matrix metalloproteinase 1 (MMP-1) expression was strongly increased in MSC after incubation with Huh-7 CM, suggesting that MSC migration depends on MMP-1 activity. The signaling pathway MAPK/ERK was activated by Huh-7 CM but its inhibition by PD98059 did not impair Huh-7 CM-induced MSC migration. Further, long-term incubation of MSC with MIP-1δ increased α-smooth muscle actin expression, suggesting its implication in the Huh-7 CM-induced evolvement of MSC into myofibroblasts. In conclusion, we report that two inflammatory cytokines, MIP-1δ and MIP-3α, are able to increase MSC migration in vitro. These cytokines might be responsible for migration and evolvement of MSC into myofibroblasts around tumors.

Clinical experience suggests fluctuation in the occurrence of osteoarticular infections. We performed a single-centre study during 2004-2012, dividing each year into the four seasons according to the Gregorian calendar. A total of 455 episodes of osteoarticular infections were retrieved. There were 91 prosthetic joint infections (45 of haematogenous origin) and 159 cases of septic arthritis. The median period between early symptoms and diagnosis of infection was 27 days. The overall number of infections per season, cumulated over the 8-year study period, was 119 in spring, 129 in summer, 95 in fall, and 112 in winter, which did not reflect any significant seasonal fluctuation. None of the different subgroups of infections, namely arthroplasties (p for trend = 0.755), haematogenous arthroplasty infections (p = 0.493), gram-negative episodes or arthritis (p = 0.290), showed any season-related fluctuation. We conclude that osteoarticular infections, including haematogenous prosthetic joint infections, do not show any significant seasonality.

Background & Aims: Mesenchymal stem cell (MSC) transplantation was shown to be effective for the treatment of liver fibrosis, but the mechanisms of action are not yet fully understood. We transplanted encapsulated human MSCs in two mouse models of liver fibrosis to determine the mechanisms behind the protective effect., Methods: Human bone marrow-derived MSCs were microencapsulated in novel alginate-polyethylene glycol microspheres. In vitro, we analyzed the effect of MSC-conditioned medium on the activation of hepatic stellate cells and the viability, proliferation, cytokine secretion, and differentiation capacity of encapsulated MSCs. The level of fibrosis induced by bile duct ligation (BDL) or carbon tetrachloride (CCl4) was assessed after intraperitoneal transplantation of encapsulated MSCs, encapsulated human fibroblasts, and empty microspheres., Results: MSC-conditioned medium inhibited hepatic stellate cell activation and release of MSC secreted anti-apoptotic (IL-6, IGFBP-2) and anti-inflammatory (IL-1Ra) cytokines. Viability, proliferation, and cytokine secretion of microencapsulated MSCs were similar to those of non-encapsulated MSCs. Within the microspheres, MSCs maintained their capacity to differentiate into adipocytes, chondrocytes, and osteocytes. 23% (5/22) of the MSC clones were able to produce anti-inflammatory IL-1Ra in vitro. Microencapsulated MSCs significantly delayed the development of BDL- and CCl4-induced liver fibrosis. Fibroblasts had an intermediate effect against CCl4-induced fibrosis. Mice transplanted with encapsulated MSCs showed lower mRNA levels of collagen type I, whereas levels of matrix metalloproteinase 9 were significantly higher. Human IL-1Ra was detected in the serum of 36% (4/11) of the mice transplanted with microencapsulated MSCs., Conclusions: MSC-derived soluble molecules are responsible for an anti-fibrotic effect in experimental liver fibrosis., (Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Thus far the ability to predict who will develop early failure following the insertion of a metal-on-metal (MoM) bearing has been very limited. Our objective was to assess the effect of smoking on failure rates in patients with MoM bearing, compared with patients with ceramic-on-polyethylene (CoP) bearing. From a prospective hospital-based registry we included all primary THAs operated upon between 1/2001 and 12/2011 with MoM or CoP bearings of the same cup design and head size (28 mm). We compared revision rates through 10/2013 classified by smoking status and type of bearing. We included 1,964 patients (median age 71, 57% women), 663 with MoM and 1,301 with CoP bearing. Mean follow-up was 6.9 years (range 1.8-12.8). Revisions were required for 56 THAs. In patients with MoM bearing the adjusted incidence rate of revision among ever-smokers was four times greater than among never-smokers (95% CI 1.4-10.9). Among those with CoP bearing, the rate ratio was only 1.3 (95% CI 0.6-2.5). We found a strong association between smoking and increased failure of MoM THAs. In contrast, the association was weak for patients with CoP bearing. Smoking might be a trigger or an effect amplifier for adverse reactions to metal debris from MoM bearings., (© 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

The clinical presentations of deep soft tissue infections can, initially, mimicry superficial skin infections such as erysipelas. However, a rapidly deteriorating health status, the spreading of the lesions and the lack of clear visual limitation of the infection on the skin are hallmarks of a more severe underlying infection, which may endanger patients' life. An immediate adequate multidisciplinary approach to therapy within a few hours is mandatory. The first step is surgical exploration with debridement of all infected tissues, accompanied by antibiotic therapy and additional supportive measures. Despite progress in the understanding of the physiopathology, the delay between suspicion of diagnosis and surgical exploration remains critical. Because of the low incidence of such severe infections, only multicenter studies might reveal deeper insights of optimal therapeutic strategies in the future and for possible improved patients' survival.

Joint-preserving surgery aims to correct the mechanical disbalances leading to the inhomogenous load distribution across joint lines, potentially leading to osteoarthritis. The possibilities of axial corrections at the knee have been known for years. A better pathophysiologic understanding of the disbalances leading to coxarthrosis has, more recently, allowed for the development of joint-preserving approaches, for instance in situations of excessive (impingement) or insufficient (dysplastic) femoro-acetabular coverage. On the opposite, in the absence of a mechanical defect, or if osteoarthritis is already present, joint-preserving surgery has little chances of success.

Objective: To determine the regulation of class II major histocompatibility complex (MHC) expression in fibroblast-like synoviocytes (FLS) in order to investigate their role as nonprofessional antigen-presenting cells in collagen-induced arthritis (CIA)., Methods: Expression of class II MHC, class II MHC transactivator (CIITA), and Ciita isoforms PI, PIII, and PIV was examined by real-time quantitative polymerase chain reaction, immunohistochemistry, and flow cytometry in human synovial tissues, arthritic mouse joints, and human and murine FLS. CIA was induced in mice in which isoform PIV of Ciita was knocked out (PIV(-/-) ), in PIV(-/-) mice transgenic for CIITA in the thymus (K14 CIITA), and in their control littermates., Results: HLA-DRA, total CIITA, and CIITA PIII messenger RNA levels were significantly increased in synovial tissue samples from patients with rheumatoid arthritis compared with the levels in tissue from patients with osteoarthritis. Human FLS expressed surface class II MHC via CIITA PIII and PIV, while class II MHC expression in murine FLS was entirely mediated by PIV. Mice with a targeted deletion of CIITA PIV lack CD4+ T cells and were protected against CIA. The expression of CIITA was restored in the thymus of PIV(-/-) K14 CIITA-transgenic mice, which had a normal CD4+ T cell repertoire and normal surface levels of class II MHC on professional antigen-presenting cells, but did not induce class II MHC on FLS. Synovial inflammation and immune responses against type II collagen were similar in PIV(-/-) K14 CIITA-transgenic mice and control mice with CIA, but bone erosion was significantly reduced in the absence of PIV., Conclusion: Overexpression of class II MHC is tightly correlated with CIITA expression in arthritic synovium and in FLS. Selective targeting of Ciita PIV in peripheral tissues abrogates class II MHC expression by murine FLS but does not protect against inflammation and autoimmune responses in CIA., (Copyright © 2011 by the American College of Rheumatology.)

Infection by Staphylococcus epidermidis is a devastating complication of metal-on-metal (MM) total hip arthroplasty (THA). Neutrophils are the first line of defense against infection, and these innate immune cells are potentially exposed to Co(2+) ions released in the peri-prosthetic tissue by the wear of MM THA. The toxicity of Co(2+) is still debated, but Co(2+) is a potential inhibitor of the Hv1 proton channel that sustains the production of superoxide by neutrophils. In this study, we show that the Co(2+) concentration in peri-prosthetic tissue from patients with MM THA averages 53 μM and that such high concentrations of Co(2+) alter the antibacterial activity of human neutrophils in vitro by inhibiting Hv1 proton channels. We show that submillimolar concentrations of Co(2+) inhibit proton currents, impair the extrusion of cytosolic acid, and decrease the production of superoxide in human neutrophils. As a result, Co(2+) reduces the ability of human neutrophils to kill two strains of Staphyloccocus epidermidis by up to 7-fold at the maximal concentration tested of 100 μM Co(2+). By inhibiting proton channels, the Co(2+) ions released by metal prostheses might therefore promote bacterial infections in patients with metal-on-metal total hip arthroplasty., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Total hip arthroplasty (THA) is one of the most common surgical procedures performed by orthopedic surgeons. Frequent indications for THA include osteoarthrosis of the hip joint that can be primary origin or secondary to dysplasia or traumatic origin, as well as fractures of the femoral neck in active patients. Other common indications include rheumatoid arthritis and osteonecrosis of the femoral head. It is a surgical intervention giving very good results giving patients pain relief and mobility with a success rate in more than 90% of cases. The point of this article is to inform the medical community on the actual situation of hip prosthetics in fields including epidemiology, clinical results, indications, contraindications, different types of prosthetic materials as well as surgical approaches.

The adequate treatment of fractures consists of a conservative or surgical approach whose goal is to assure a rapid solidity of the fracture site that will lead to a durable complete healing without complications. Fracture healing criteria remain controversial. In this article we are trying to present the tools used in the evaluation of bone consolidation and propose therapeutical guidelines aiming at the return to daily activities in full security.