Search

Background: We evaluated the reliability of intraoperative assessment of leukocyte esterase (LE) in synovial fluid samples from patients undergoing reimplantation following implant removal and spacer insertion for periprosthetic joint infection (PJI). Our hypothesis was that a positive intraoperative LE test would be a better predictor of persistent infection than either serum C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) or the combination of serum CRP and ESR. Methods: The records of 76 patients who received a 2-stage exchange for PJI were retrospectively reviewed. Synovial fluid was collected for LE measurement during surgery before arthrotomy in 79 procedures. Receiver operating characteristic curves were generated. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the curve (AUC) of LE, CRP, ESR, and CRP + ESR were calculated. Results: Sensitivity, specificity, positive predictive value, and negative predictive value of the LE assay were 82%, 99%, 90%, and 97%, respectively. Receiver operating characteristic analysis revealed an LE threshold of 1.5 between the first (negative) and the second (positive) level of the ordinal variable, so that a grade starting from 1+ was accurate for a diagnosis of persistent infection (AUC 0.9044). The best thresholds for the CRP and the ESR assay were 8.25 mg/L (82% sensitivity, 84% specificity, AUC 0.8416) and 45 mm/h (55% sensitivity, 87% specificity, AUC 0.7493), respectively. Conclusion: The LE strip test proved a reliable tool to diagnose persistence of infection and outperformed the serum CRP and ESR assays. The strip test provides a valuable intraoperative diagnostic during second-stage revision for PJI.

Background:To diagnose periprosthetic joint infection (PJI) preoperatively, ultrasound-guided joint aspiration (US-JA) may not be performed when effusion is minimal or absent. We aimed to report and investigate the diagnostic performance of ultrasound-guided periprosthetic biopsy (US-PB) of synovial tissue to obtain joint samples in patients without fluid around the implants. Methods:One-hundred nine patients (55 men; mean age: 68 ± 13 years) with failed total hip arthroplasty (THA) who underwent revision surgery performed preoperative US-JA or US-PB to rule out PJI. Results:Sixty-nine of 109 patients had joint effusion and underwent US-JA, while the remaining 40 with dry joint required US-PB. Thirty-five of 109 patients (32.1%) had PJI, while 74/109 (67.9%) had aseptic THA failure. No immediate complications were observed in both groups. Technical success of US-PB was 100%, as the procedure was carried on as planned in all cases. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of US-JA were 52.2%, 97.8%, 92.3%, 80.3%, and 82.6%, while for US-PB, they were 41.7%, 100%, 100%, 80%, and 82.5%, respectively, with no significant difference (P = .779). Using the final diagnosis as reference standard, we observed a moderate agreement with both US-JA (k = 0.56) and US-PB (k = 0.50). Conclusion:We present a novel US-guided technique to biopsy periprosthetic synovial tissue of failed THA to rule out PJI. We found similar diagnostic performance as compared with traditional US-JA. This supports future larger studies on this procedure that might be applied in patients without joint effusion.

Background: Dual mobility (DM) has been shown to improve stability both in primary and revision total hip arthroplasty (THA) and is increasingly used in patients at high risk of dislocation and in the treatment of THA instability. The introduction of modular liners has helped to overcome some of the limitations of monoblock DM cups. In this context, the use of a ceramic liner would avoid the conventional cobalt-chromium liner in the titanium shell, which can be problematic in some situations. The aim of this paper is to report the outcomes of a consecutive series of patients undergoing revision THA using a modular DM cup with a ceramic liner instead of the conventional metal one, and to clarify the rationale for this currently “off-label” use. Patients and methods: This is a retrospective series of patients who received this new DM bearing in a single institution. Patients were followed up clinically and radiologically at 1 month, 3 months, 6 months and yearly thereafter. Results: 5 patients received the ceramic liner in the study period (2014–2019). The indications were instability or high risk of dislocation in ceramic liner fracture and ARMD with soft tissue damage after MoM THA. The mean age at surgery was 74 (63–82) years, the mean follow-up was 36 (12–72) months. No dislocation occurred, and no adverse events related to the implant were recorded. Conclusions: The use of a ceramic liner in a modular DM cup offers several advantages in selected patients, and the results of our cohort are encouraging. However, caution is needed in introducing this new bearing because knowledge is currently limited. Further studies on a larger number of patients and with longer follow-ups are needed to confirm these findings and before widespread use of the device.

Purpose To plan for the continuance of elective hip and knee arthroplasty during a resurgence or new wave of COVID-19 infections. Method A systematic review was conducted using the terms “COVID-19” or “SARS-Cov-2” and “second wave”. No relevant citations were found to inform on recommendations the plan. Therefore, an expert panel of the European Hip Society and the European Knee Associates was formed to provide the recommendations. Results Overall, the recommendations consider three phases; review of the first wave, preparation for the next wave, and during the next wave. International and national policies will drive most of the management. The recommendations focus on the preparation phase and, in particular, the actions that the individual surgeon needs to undertake to continue with, and practice, elective arthroplasty during the next wave, as well as planning their personal and their family’s lives. The recommendations expect rigorous data collection during the next wave, so that a cycle of continuous improvement is created to take account of any future waves. Conclusions The recommendations for planning to continue elective hip and knee arthroplasty during a new phase of the SARS-Cov-2 pandemic provide a framework to reduce the risk of a complete shutdown of elective surgery. This involves engaging with hospital managers and other specialities in the planning process. Individuals have responsibilities to themselves, their colleagues, and their families, beyond the actual delivery of elective arthroplasty.

The transition from shutdown of elective orthopaedic services to the resumption of pre-COVID-19 activity presents many challenges. These include concerns about patient safety, staff safety, and the viability of health economies. Careful planning is necessary to allow patients to benefit from orthopaedic care in a safe and sustainable manner. Cite this article: Bone Joint J 2020;102-B(7):807–810.

Purpose The COVID-19 pandemic is importantly affecting the orthopaedic practice all over the world with Northern Italy being the first European area that faced the worst scenario. In this study, the changes in clinical practice occurred in an orthopaedic center in Milan are described. Methods Number and type of admissions, outpatients cancelled and preserved, emergency room, and intensive care unit activities have been analyzed in the timeframe of seven weeks since the beginning of the pandemic (from February 24th to April 10th) and compared with the same period in 2019. Results The planned surgical admissions declined from 2172 in 2019 to 664 in 2020 (69.42%, p

Background Periprosthetic fractures (PPFs) are a growing matter for orthopaedic surgeons, and patients with PPFs may represent a frail target in the case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The purpose of this study is to investigate whether hospital reorganisations during the most severe phase of the SARS-CoV-2 pandemic affected standards of care and early outcomes of patients treated for PPFs in Northern Italy. Materials and methods Data were retrieved from a multicentre retrospective orthopaedics and traumatology database, including 14 hospitals. The following parameters were studied: demographics, results of nasopharyngeal swabs, prevalence of coronavirus disease 2019 (COVID-19), comorbidities, general health status (EQ-5D-5L Score), frailty (Clinical Frailty Scale, CFS), pain (visual analogue scale, VAS), anaesthesiologic risk (American Society of Anaesthesiology Score, ASA Score), classification (unified classification system, UCS), type of operation and anaesthesia, in-hospital and early complications (Clavien–Dindo Classification, CDC), and length of stay (LOS). Data were analysed by means of descriptive statistics. Out of 1390 patients treated for any reason, 38 PPFs were included. Results Median age was 81 years (range 70–96 years). Twenty-three patients (60.5%) were swabbed on admission, and two of them (5.3%) tested positive; in three patients (7.9%), the diagnosis of COVID-19 was established on a clinical and radiological basis. Two more patients tested positive post-operatively, and one of them died due to COVID-19. Thirty-three patients (86.8%) presented a proximal femoral PPF. Median ASA Score was 3 (range, 1–4), median VAS score on admission was 3 (range, 0–6), median CFS was 4 (range, 1–8), median EQ-5D-5L Score was 3 in each one of the categories (range, 1–5). Twenty-three patients (60.5%) developed post-operative complications, and median CDC grade was 3 (range, 1–5). The median LOS was 12.8 days (range 2–36 days), and 21 patients (55.3%) were discharged home. Conclusions The incidence of PPFs did not seem to change during the lockdown. Patients were mainly elderly with comorbidities, and complications were frequently recorded post-operatively. Despite the difficult period for the healthcare system, hospitals were able to provide effective conventional surgical treatments for PPFs, which were not negatively influenced by the reorganisation. Continued efforts are required to optimise the treatment of these frail patients in the period of the pandemic, minimising the risk of contamination, and to limit the incidence of PPFs in the future. Level of evidence IV.

Background: Periprosthetic femoral fractures (PPF) are a devastating complication after total hip arthroplasty (THA). Both trauma and adult reconstruction surgeons or combined teams treat these fractures following management algorithms. The aim of this study is to investigate the current treatment of PPF by members of the European Hip Society (EHS). Methods: An online survey of the members of the European Hip Society (EHS) was conducted. 20 cases of periprosthetic fracture were presented and surgeons were asked to answer questions regarding classification, treatment and postoperative treatment protocol. Results: A total of 132 (130 male; 2 female) EHS members responded. Mean years in surgical practice was 18.8 (min. 1 year; max. 50 years). The preferred surgical method was combined open reduction and internal fixation (ORIF) (30.3%) for AG fractures, ORIF with cables (30.4%) for AL fractures, combined ORIF (cable and plate) for B1 fractures (49.2%), stem revision with cables for B2 fractures (73.1%), stem revision with cables for B3 (55.9%) fractures and combined ORIF (cable and plate: 55.5%) for C fractures. Surprisingly, 10.8% suggested various stem revision techniques for B1 and 17.4% for C fractures. Strong variations were observed regarding postoperative weight-bearing protocol. Conclusions: A strong consensus was found for the choice of conservative or surgical treatment of the different PPF types according to the Vancouver Classification. Various stem revision techniques were the preferred surgical techniques for Vancouver B2 (91.2%) and B3 (88.6%) fractures. However, for postoperative weight-bearing, when the ORIF technique was used, a significant variation of protocols was found.

Purpose We previously described the radical changes occurred in an orthopaedic hospital in Milan (Italy) during the first SARS-CoV-2 pandemic outbreak. Currently, during the second wave, the situation is still far from normality. Here we describe the changes that took place, and are still ongoing, in the clinical practice. Methods Number and type of admissions, outpatients activity, ER and urgent procedures in SARS-CoV-2 negative and positive patients have been analyzed over seven weeks (October 26th–December 13th, 2020) and compared with the correspondent period in 2019 and the same timeframe during the first wave (February 24th–April 10th). Results 2019 vs. 2020: Overall admissions decreased by 39.8%; however, while admissions for elective surgery dropped by 42.0%, urgent surgeries increased by 117.0%. Rehabilitation admissions declined by 85.2%. White and green priority ER consultations declined by 41.6% and 52.0%, respectively; yellow and red increased by 766.7% and 400.0%, respectively. Second vs. first wave: Overall admissions increased by 58.6% with a smoother decrement in weekly admissions than during the first wave. Disparity of acute admissions vs. rehabilitation expanded: Acute cases increased by 63.6% while rehabilitation cases decreased by 8.7%. Admissions to triage procedures increased by 72.3%. Conclusions Activity levels are far from normality during the second COVID-19 wave. Elective surgery and outpatients-related activities are still strongly limited compared to 2019 while the number of urgent cases treated increased consistently. SARS-CoV-2 positive emergencies are slightly higher than during the first wave. These important changes are expected to impact on health service and hospital budget for long.

Purpose During the COVID-19 pandemic there has been a massive reduction of arthroplasty services due to reallocation of hospital resources. The unique challenge for clinicians has been to define which arthroplasty patients most urgently require surgery. The present study aimed to investigate priority arthroplasty procedures during the pandemic and in the reinstatement period from the surgeon’s perspective. Material and methods An online survey was conducted among members of the European Hip Society (EHS), European Knee Associates (EKA) and other invited orthopaedic arthroplasty surgeons (experts) from across the world. The survey consisted of 17 different arthroplasty procedures/indications of which participants were asked to choose and rank the most important 10. Results Four hundred and thirty-nine arthroplasty surgeons from 44 countries responded. The EHS and EKA had a 43% response rate of members. In weighted average points, the majority of respondents (67.5 points) ranked ‘acute fractures requiring arthroplasty (Periprosthetic fractures, THA/hemi-arthroplasty for femoral neck fractures)’ as priority indication number one, followed by ‘first-stage explantations for acute PJI (periprosthetic joint infection)’ in second place and priority indication (45.9 points) three as ‘one-stage revision for acute PJI’ (39.7 points). Conclusions There was agreement that femoral neck fractures, periprosthetic fractures, and acute infections should be prioritised and cannot be postponed in the setting of the COVID-19 pandemic. As arthroplasty procedures are being resumed in most countries now, there has also been a relaxation of lockdown rules in most countries, which might cause a so-called second wave of the pandemic. Therefore, the results of the current study present a proposal by experts as to which operations should be prioritised in the setting of a second wave of the pandemic.

Background Treatment of hip fractures during the coronavirus disease 2019 (COVID-19) pandemic has posed unique challenges for the management of COVID-19-infected patients and the maintenance of standards of care. The primary endpoint of this study is to compare the mortality rate at 1 month after surgery in symptomatic COVID-positive patients with that of asymptomatic patients. A secondary endpoint of the study is to evaluate, in the two groups of patients, mortality at 1 month on the basis of type of fracture and type of surgical treatment. Materials and methods For this retrospective multicentre study, we reviewed the medical records of patients hospitalised for proximal femur fracture at 14 hospitals in Northern Italy. Two groups were formed: COVID-19-positive patients (C+ group) presented symptoms, had a positive swab for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and received treatment for COVID-19; COVID-19-negative patients (C− group) were asymptomatic and tested negative for SARS-CoV-2. The two groups were compared for differences in time to surgery, survival rate and complications rate. The follow-up period was 1 month. Results Of the 1390 patients admitted for acute care for any reason, 477 had a proximal femur fracture; 53 were C+ but only 12/53 were diagnosed as such at admission. The mean age was > 80 years, and the mean American Society of Anesthesiologists (ASA) score was 3 in both groups. There was no substantial difference in time to surgery (on average, 2.3 days for the C+ group and 2.8 for the C− group). As expected, a higher mortality rate was recorded for the C+ group but not associated with the type of hip fracture or treatment. No correlation was found between early treatment ( Conclusions Hip fracture in COVID-19-positive patients accounted for 11% of the total. On average, the time to surgery was > 48 h, which reflects the difficulty of maintaining normal workflow during a medical emergency such as the present pandemic and notwithstanding the suspension of non-urgent procedures. Hip fracture was associated with a higher 30-day mortality rate in COVID-19-positive patients than in COVID-19-negative patients. This fact should be considered when communicating with patients and/or their family. Our data suggest no substantial difference in hip fracture management between patients with or without COVID-19 infection. In this sample, the COVID-19-positive patients were generally asymptomatic at admission; therefore, routine screening is recommended. Level of evidence Therapeutic study, level 4.

Background: From 10 March up until 3 May 2020 in Northern Italy, the SARS-CoV-2 spread was not contained, disaster triage was adopted. The aim of the present study is to assess the impact of the COVID-19-pandemic on the Orthopedic and Trauma departments, focusing on: hospital reorganization (flexibility, workload, prevalence of COVID-19/SARS-CoV-2, standards of care), effects on staff, subjective orthopedic perception of the pandemic. Material and Methods: Data regarding 1390 patients and 323 surgeons were retrieved from a retrospective multicentric database, involving 14 major hospitals. The subjective directors’ viewpoints regarding the economic consequences, communication with the government, hospital administration and other departments were collected. Results: Surgical procedures dropped by 73%, compared to 2019, elective surgery was interrupted. Forty percent of patients were screened for SARS-CoV-2: 7% with positive results. Seven percent of the patients received medical therapy for COVID-19, and only 48% of these treated patients had positive swab tests. Eleven percent of surgeons developed COVID-19 and 6% were contaminated. Fourteen percent of the staff were redirected daily to COVID units. Communication with the Government was perceived as adequate, whilst communication with medical Authorities was considered barely sufficient. Conclusions: Activity reduction was mandatory, the screening of carriers did not seem to be reliable and urgent activities were performed with a shortage of workers and a slower workflow. A trauma network and dedicated in-hospital paths for COVID-19-patients were created. This experience provided evidence for coordinated responses in order to avoid the propagation of errors.

Purpose The SARS-CoV-2 outbreak affected health care systems at different levels with important consequences on health, economy, and social structures. This paper aims to analyse the impact on surgical block utilisation and efficiency in an orthopaedics reference centre in Northern Italy. Methods The timeframe chosen for the current analysis was April 2020, to be compared with the corresponding period in 2019. Number and type of procedures, first case delay, occupancy rate, and turnover time were used as indicators to benchmark the activities. Results The overall number of surgical procedures decreased by 57%, from 537 in 2019 to 230 in the same timeframe in 2020. Orthopaedic procedures predominated in 2019, with 434 cases (80.8%), while in 2020, trauma was the leading activity, with 200 cases (86.9%). Orthopaedic surgery had a relative decrement of 93% while trauma has relatively increased by 94%. Mean first case delay in orthopaedic room (OR) was two hours and 36 minutes (SD 01:40:21) in 2020 compared with only 19 minutes (SD 00:02:15) in 2019. OR occupancy rate was 59% in 2020 compared with 89% in 2019. Turnover time raised from 21 minutes in 2019 to 53 min in 2020. Conclusions These data clearly show the deep impact of COVID-19 pandemic on OR facilities. Efficiency indicators fell dramatically in April 2020 compared with the corresponding period in 2019. This scenario will deeply affect both the waiting lists and the economic burden of the hospital. Regaining efficiency and maintaining the quality and safety of the process while restoring elective orthopaedic surgery are among the main challenges that surgeons will face in the next time.

Purpose The Covid-19 pandemic has disrupted health care systems all over the world. Elective surgical procedures have been postponed and/or cancelled. Consensus is, therefore, required related to the factors that need to be in place before elective surgery, including hip and knee replacement surgery, which is restarted. Entirely new pathways and protocols need to be worked out. Methods A panel of experts from the European Hip Society and European Knee Association have agreed to a consensus statement on how to reintroduce elective arthroplasty surgery safely. The recommendations are based on the best available evidence and have been validated in a separate survey. Results The guidelines are based on five themes: modification and/or reorganisation of hospital wards. Restrictions on orthopaedic wards and in operation suite(s). Additional disinfection of the environment. The role of ultra-clean operation theatres. Personal protective equipment enhancement. Conclusion Apart from the following national and local guidance, protocols need to be put in place in the patient pathway for primary arthroplasty to allow for a safe return.

Background Coronavirus disease 2019 (COVID-19) pandemic poses an important risk to global health. Methods This study surveyed 370 international orthopedic surgeons affiliated with the American Association of Hip and Knee Surgeons to help identify the global impact of the COVID-19 pandemic on patient care. Results A total of 99 surgeons (27% of those surveyed) completed the questionnaire representing 32 different countries. Except for surgeons in Japan, all respondents noted that their practice had been affected to some degree and 70% of the surgeons have canceled elective procedures. More than a third of the surgeons have had to close their practices altogether and the remaining open practices were estimated to be sustainable for 7 weeks on average given their current situation. Conclusion The COVID-19 pandemic has resulted in marked changes to the majority of international arthroplasty practices.

Background Very little has been published about the diagnostic performance of MRI in total hip arthroplasty (THA) infection. Purpose To determine the diagnostic performance of conventional MRI features and of new lymph nodal indices to identify infection in patients with failed THA. Study type Retrospective. Population In all, 119 patients (66 females; age 66.9 ± 12.4 years) with failed THA. Field strength/sequences Metal artifact reduction sequence (MARS) protocol including short tau inversion recovery and turbo spin-echo T1 - and T2 -weighted sequences at 1.5T. Assessment Patients underwent pelvis MRI prior to failed THA revision. MRIs were reviewed to identify periprosthetic bone destruction, soft-tissue mass, effusion, synovitis, lamellated synovitis, extracapsular edema, fibrous periprosthetic membrane, bone edema, and extracapsular collection/sinus tract. The number and maximum diameter of inguinal, obturator and iliac lymph nodes of the affected hip were assessed and normalized to those of the unaffected hip to calculate the ratio of nodal size (RNS), ratio of node number (RNN), difference of nodal size (DNS), and difference of node number (DNN). Statistical tests The Mann-Whitney U-and chi-square test were used. Diagnostic performance of indices and odds ratios (OR) were calculated. Results RNS, RNN, DNS, and DNN indices were significantly different (P = 0.000) between infected and noninfected THA, with accuracies ranging from 84.8% (RNS) and 93.1% (RNN). All other MRI features were significantly more prevalent in infected THA (P ≤ 0.002), except bone destruction, periarticular soft-tissue mass, and fibrous membrane (P ≥ 0.031). Sensitivities ranged from 7.9% (soft-tissue mass) to 76.3% (effusion/bone edema), specificity from 45.7% (bone destruction) to 97.5% (synovitis/lamellated synovitis), accuracy from 49.6% (bone destruction) to 81.5% (synovitis), OR from 0.261 (soft-tissue mass) to 35.550 (synovitis). Data conclusion Conventional MRI features have limited accuracy to differentiate septic and aseptic THA failure. Lymph nodal indices, particularly those related to nodal number, may represent biomarkers of THA infection. Evidence level 3 TECHNICAL EFFICACY STAGE: 2.

Purpose The aim of the present study was to evaluate the impact of the coronavirus (COVID-19) pandemic on joint arthroplasty service in Europe by conducting an online survey of arthroplasty surgeons. Methods The survey was conducted in the European Hip Society (EHS) and the European Knee Associates (EKA). The survey consisted of 20 questions (single, multiple choice, ranked). Four topics were addressed: (1) origin and surgical experience of the participant (four questions); (2) potential disruption of arthroplasty surgeries (12 questions); (3) influence of the COVID-19 pandemic on the particular arthroplasty surgeon (four questions); (4) a matrix provided 14 different arthroplasty surgeries and the participant was asked to state whether dedicated surgery was stopped, delayed or cancelled. Results Two-hundred and seventy-two surgeons (217 EHS, 55 EKA) from 40 different countries participated. Of the respondents, 25.7% stated that all surgeries were cancelled in their departments, while 68.4% responded that elective inpatient procedures were no longer being performed. With regard to the specific surgical procedures, nearly all primary TJA were cancelled (92.6%) as well as aseptic revisions (94.7%). In most hospitals, periprosthetic fractures (87.2%), hip arthroplasty for femoral neck fractures and septic revisions for acute infections (75.8%) were still being performed. Conclusion During the current 2020 COVID-19 pandemic, we are experiencing a near-total shutdown of TJA. A massive cutback was observed for primary TJA and revision TJA, even in massively failed TJA with collapse, dislocation, component failure or imminent dislocation. Only life-threatening pathologies like periprosthetic fractures and acute septic TJA are currently undergoing surgical treatment. Level of evidence V. Electronic supplementary material The online version of this article (10.1007/s00167-020-06033-1) contains supplementary material, which is available to authorized users.

Background The Coronavirus disease 2019 (COVID-19) outbreak has put strain on many healthcare systems around the world, with important consequences. The aim of this paper is to describe the impact of the COVID-19 pandemic on hip and knee arthroplasties in an Italian high-volume orthopedic center, located in the region of the country first and worst affected by the Coronavirus. Methods Data from an institutional database were retrospectively analyzed to obtain the number of hip and knee arthroplasties performed from February 24 to April 10 2020. The figures were compared with those of the same 7-week period of the last year (2019). Results The number of hip and knee arthroplasties showed a decrease from 706 in the same period of 2019 to 166 (76.5% less) in the current year. In 2019, a mean of 101 ± 9 hip and knee arthroplasties were performed per week compared with a mean of 24 ± 34 in 2020. Ten patients tested positive for SARS-CoV2 during their hospital stay. Two of these patients died after a regular postoperative period after developing unexpectedly COVID-19 during rehabilitation. The mortality in the 7-week period of the current year was 1.2% compared with 0% in 2019. Conclusion The outbreak of COVID-19 had a considerable effect in our center on the number of hip and knee arthroplasties that rapidly decreased to 0 in parallel to the worsening of the situation in the country. Efforts will be soon requested because our practice is going to deal with the after-effects of the pandemic in the near future.

The aim of this study was to investigate the hypothesis that a two-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, may provide better infection cure rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic hip infection. In this case-control study, 27 patients, treated with a two-stage procedure, using cementless implants coated with an antibiotic-loaded hydrogel (DAC®, “Defensive Antibacterial Coating”), were compared with 27 matched controls, treated with a two-stage cementless revision procedure, without the coating. At a mean follow-up of 2.7 (minimum 2.1–maximum 3.5) years, no evidence of infection, implant loosening, or adverse events were observed in the DAC-treated group, compared to four cases of infection recurrence in the control group. Although in a relatively limited series of patients our data show that cementless two-stage hip revision, performed with an antibacterial hydrogel coating, may provide better infection control than two-stage without the coating, with reduced hospitalization time, these findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections.

Background The study’s aim was to summarize the recommendations given by members of the European Hip Society (EHS) regarding sport activities after total hip arthroplasty (THA). Methods Members of the EHS were invited to complete an online web-based questionnaire including recommendations for 47 sports disciplines. The questions regarding the specific sports were also divided into 4 subcategories: “allowed,” “allowed when experienced,” “not allowed”, and “no opinion.” Four intervals for resuming the sports activities after THA were evaluated: within 6 weeks after THA, 6 to 12 weeks after THA, 12 weeks to 6 months after THA, and more than 6 months after THA. Consensus on resuming sports was analyzed. Results A total of 150 (32.9%) EHS members participated in the survey. Agreement was found for 5 sports activities in the first 6 weeks after THA, for 10 activities, 6 to 12 weeks after surgery, for 26 activities, 3 to 6 months after THA, and for 37 of 47 activities, 6 months after surgery. Sports activities which were not allowed after THA were handball, soccer and football, basketball, full contact sports, and martial arts. Conclusion This is the first report describing the recommendations of European hip arthroplasty surgeons on resuming sport activity after THA. Most physical activities were allowed for the patients 6 months after THA. The experience of the patient in performing a distinct sport activity did not influence the recommendations to return to former sports activities. European surgeons are progressively mitigating restrictions to sports after THA. Further studies should evaluate the effects of this trend on patients' outcome and implant survival.

Background: Instability and dislocation after total hip arthroplasty (THA) is a common reason for revision surgery. THA head-neck adapters promise the reconstruction of optimal femoral offset and leg length in revision THA (rTHA) while retaining stable implants. The aim of this retrospective multi-centre study is to report on the results achieved with the use of head adapters in partial rTHA, to avoid the instability of the implant. Methods: 55 cases of partial rTHA performed between February 2015 and April 2017 in 3 different hospitals using the Bioball Head Adapter (BHA) (Bioball Merete, Medical GmbH, Berlin, Germany) were retrospectively recorded. All patients were evaluated from a radiological point of view at an average follow-up of 3.5 years. Failure was defined as re-revision surgery for any cause as well as a subjective feeling of instability of the joint. Results: One failure was registered in an extreme case and radiological findings show no suggestive signs of radiolucencies or loosening and therefore all implants have been considered stable. Conclusions: Despite some limitations of this retrospective study and according to the relevant literature, our data confirms that BHA is a safe system that allows the flexibility to restore femoral offset and version, to adjust leg length, to minimise instability, to avoid unnecessary removal of otherwise well-fixed components thus improving tribology and reducing the risk of taper junction issues without major complications in partial rTHA.

Purpose The COVID-19 pandemic has disrupted the health care system around the entire globe. A consensus is needed about resuming total hip and knee procedures. The European Hip Society (EHS) and the European Knee Association (EKA) formed a panel of experts that have produced a consensus statement on how the safe re-introduction of elective hip and knee arthroplasty should be undertaken. Methods A prospective online survey was done among members of EHS and EKA. The survey consisted of 27 questions. It includes basic information on demographics and details the participant’s agreement with each recommendation. The participant could choose among three options (agree, disagree, abstain). Recommendations focussed on pre-operative, peri-operative, and post-operative handling of patients and precautions. Results A total of 681 arthroplasty surgeons participated in the survey, with 479 fully completing the survey. The participants were from 44 countries and 6 continents. Apart from adhering to National and Local Guidelines, the recommendations concerned how to make elective arthroplasty safe for patients and staff. Conclusion The survey has shown good-to-excellent agreement of the participants with regards to the statements made in the recommendations for the safe return to elective arthroplasty following the first wave of the COVID-19 pandemic.

Reinstating elective hip and knee arthroplasty services presents significant challenges. We need to be honest about the scale of the obstacles ahead and realise that the health challenges and economic consequences of the COVID-19 pandemic are potentially devastating.We must also prepare to make difficult ethical decisions about restarting elective hip and knee arthroplasty. These decisions should be based on the existing evidence-base, reliable data, the recommendations of experts, and regional circumstances.

Aims Leucocyte esterase (LE) has been shown to be an accurate marker of prosthetic joint infection (PJI), and has been proposed as an alternative to frozen section (FS) histology for intraoperative diagnosis. In this study, the intraoperative assessment of LE was compared with FS histology for the diagnosis of prosthetic hip infection. Patients and Methods A total of 119 patients undergoing revision total hip arthroplasty (THA) between June 2015 and December 2017 were included in the study. There were 56 men and 63 women with a mean age of 66.2 years (27 to 88). Synovial fluid was collected before arthrotomy for the assessment of LE using enzymatic colourimetric strips. Between five and six samples were stained with haematoxylin and eosin for FS histology, and considered suggestive of infection when at least five polymorphonuclear leucocytes were found in five high-power fields. Results The sensitivity and specificity of the LE assay were 100% and 93.8%, respectively; the positive (PPV) and the negative (NPV) predictive values were 79.3% and 100%, respectively. The mean time between the collection of the sample and the result being known was 20.1 minutes (sd 4.4). The sensitivity and specificity of FS histology were 78.3% and 96.9%, respectively; the PPV and the NPV were 85.7% and 94.9%, respectively. The mean time between the collection of the sample and the result being known was 27.2 minutes (sd 6.9). Conclusion The sensitivity of LE assay was higher, with similar specificity and diagnostic accuracy, compared with FS histology. The faster turnaround time, its ease of use, and low costs make LE assay a valuable alternative to FS histology. We now use it routinely for the intraoperative diagnosis of PJI. Cite this article: Bone Joint J 2019;101-B:372–377.

Intra-articular administration of adipose-derived mesenchymal stem cells (ASCs), either in vitro expanded or within adipose tissue-based products obtained at point-of-care, has gained popularity as innovative regenerative medicine approach for osteoarthritis (OA) treatment. ASCs can stimulate tissue repair and immunomodulation through paracrine factors, both soluble and extracellular vesicles (EV) embedded, collectively defining the secretome. Interaction with the degenerative/inflamed environment is a crucial factor in understanding the finely tuned molecular message but, to date, the majority of reports have described ASC-secretome features in resting conditions or under chemical stimuli far from the in vivo environment of degenerated OA joints. In this report, the secretory profile of ASCs treated with native synovial fluid from OA patients was evaluated, sifting 200 soluble factors and 754 EV-embedded miRNAs. Fifty-eight factors and 223 EV-miRNAs were identified, and discussed in the frame of cartilage and immune cell homeostasis. Bioinformatics gave a molecular basis for M2 macrophage polarization, T cell proliferation inhibition and T reg expansion enhancement, as well as cartilage protection, further confirmed in an in vitro model of OA chondrocytes. Moreover, a strong influence on immune cell chemotaxis emerged. In conclusion, obtained molecular data support the regenerative and immunomodulatory properties of ASCs when interacting with osteoarthritic joint environment.

Introduction: Metal-on-metal (MoM) large head total hip arthroplasties (THAs) were discontinued early after their introduction because of the high number of failures due to adverse reaction to metal debris (ARMD). Aim of this study is to report the clinical outcome at a mid-term follow-up (FU) of a series of large-head MoM THA. Methods: In this prospective study, 25 hips (24 patients, 3 males, 21 females, mean age 62.44 years) who have undergone primary THA with large head (diameter ⩾36 mm) MoM prosthesis were evaluated. Each patient underwent a standard follow-up after surgery, that included blood tests with metal ion levels (Co and Cr), x-ray of the pelvis, metal artifact reduction sequence magnetic resonance imaging (MARS-MRI) and clinical evaluation. Results: At an average follow-up of 7.3 years, 4 hips have been surgically reviewed: 2 for causes not related to ARMD (1 heterotopic ossification and 1 periprosthetic fracture); the other 2 on the same patient (bilateral) with ARMD, who was eventually found to be allergic to nickel. Increased metal ions, osteolysis and severe MRI alterations were found in patients with ARMD. Asymptomatic alterations at MRI were found in 8 patients. Harris Hip Score improved after surgery from a mean of 51 points to a mean of 90 points ( p < 0.01). Conclusions: The findings of this study show that not all the patients with MoM THA will develop clear symptoms of ARMD at mid-term follow-up. Patients should be closely monitored following protocols such as that proposed in the European Consensus Statement.

Background Ceramic-on-ceramic (CoC) bearings due to their mechanical properties can be used in primary total hip arthroplasty (THA) especially in young patients requiring a long-lasting implant. The goal of this study is to analyze the results of a series of 200 consecutive CoC THAs in patients aged 50 years or less at the time of surgery. Methods A retrospective study was conducted on the first 200 consecutive CoC arthroplasties performed using the direct lateral approach on 105 females and 81 males (14 bilateral cases) with an average age of 44.2 (16-50) years. The diagnosis was primary or post-traumatic osteoarthritis in 94 cases, avascular necrosis of the femoral head in 47, displaced intracapsular femoral neck fracture in 29, osteoarthritis secondary to developmental dysplasia of the hip/Legg-Calve-Perthes disease/slipped capital femoral epiphysis in 20, and rheumatic diseases in 10 cases. The preoperative Harris Hip Score was 32.5 on average (range 15-55). All the implants were cementless. In 177 THAs the coupling was alumina-on-alumina, and in 23 cases the coupling was AMC-on-AMC (alumina matrix composite). Results Twenty-five patients with 28 THAs were lost at the final follow-up, 2 stems were revised due to subsidence, 1 cup was revised due to malposition, 1 femoral head was changed because of impingement, and 1 THA was revised for periprosthetic infection. Three patients sustained a Vancouver B1 periprosthetic femoral fracture. At the final follow-up (mean 14.9 years; minimum 5 years to maximum 24 years), 172 THAs were eligible for clinical and radiographic evaluation: none was revised for wear and/or breakage of the ceramic components. Harris Hip Score rose up to a mean value of 90.1 (52-100). Conclusion The present report demonstrates that CoC coupling offers excellent long-term results in THA performed in young patients with very low wear and no adverse effects caused by the material.

There is some uncertainty about the bearing to be used to substitute a broken ceramic. Using metal components (head or liner) may lead to catastrophic wear of the metal.The purpose of this article is to describe the long-term follow-up result of ceramic fracture replaced with metal-on-polyethylene (MoP).We report 3 cases of ceramic head fracture after ceramic-on-ceramic (CoC) total hip arthroplasty (THA) in which the broken ceramic was replaced with MoP.All cases developed severe complications due to gross wear of the metal head: one developed a pseudotumour after a few months while the other 2 had significant local metallosis and toxic blood metal levels.When there is a fracture of a ceramic component, we advise caution with the use of metal heads, as small ceramic fragments can cause 3rd-body wear with massive metal debris and severe local and general complications.

Introduction: Failures due to adverse reaction to metal debris (ARMD) have become an area of common focus among surgeons performing hip replacements. Several authors have reported data on the prevalence of these masses, in both symptomatic and asymptomatic patients after either large-diameter head metal-on-metal (MoM) total hip arthroplasty (THA) or hip resurfacing arthroplasty, with a large variability of rate. To our knowledge, few data are reported on the association of this lesion with the use of small-head diameter MoM. Methods: 15 hips that were revised for ARMD in small-head MoM THA were included in this study. We focused our attention on the difficulties of diagnosis and treatment and also on the histologic aspects of the harvested pathologic tissue. Results: The histological examination of our cases showed a presence of lymphocytic infiltrate suggesting a delayed hypersensitivity reaction to the metal of type IV (ALVAL), but different from each other in term of the prevalence of the cellular component. Osteolysis and severe soft tissue damage were also observed. Revision resulted in remission of the lesion and successful implant. Conclusions: Our observation suggests that the evidence of ARMD should be considered even in case of small-head MoM arthroplasty and therefore these patients should be followed scrupulously with 2nd level diagnostic tools such as magnetic resonance imaging with metal artifact reduction sequence (MARS-MRI) and metal ion levels at least once. Further investigations are necessary to establish the real prevalence of this phenomenon in the whole population of small-head MoM THAs.

Total hip arthroplasty is considered one of the greatest advances in health care of the last century. More than one million THAs are estimated to be performed annually and an increasing number of revisions are expected in the future. Osteolysis and loosening are still the main reasons for failure, justifying the use of low-wear bearings.The aim of this paper is to describe the mode of failure of the different couplings (polyethylene, cross-linked PE, metal, ceramic) and the options of treatment considering the various scenarios that the surgeon has to face nowadays in the case of failure related to articulation material. A comprehensive algorithm of treatment strategies is proposed based on the best current evidence and on the authors' experience.Periodical follow-up, indications for early revision, selection of proper surgical techniques and tribology are suggested. Nowadays, few rules are strongly recommended: trying to avoid any metal in case of failure of metal-on-metal; to avoid metal in fracture of ceramic; never to mix metals or ceramics from different manufactures. We aim to address a great number of open questions. There is still need for further research and evidences in this essential field of orthopaedic surgery.

Following the increasing number of total hip arthroplasties, the amount of hip revision procedures continue to rise. Careful patient selection and bone loss evaluation is crucial for a correct management of femoral revision procedures. The key point in femoral revision is to obtain a reliable primary stability of the stem, with the least invasive implant as possible, to preserve and if possible to restore the bone stock. In this article we present the indications and the techniques for the femoral revisions most commonly used in Europe, referring to the evidence in the literature and our personal experiences.

We analyzed specific features of chondrocytes as cellular yield, cell doubling rates and the dependence between these parameters and patient-related data in a set of 211 osteoarthritic (OA) patients undergoing total joint replacement. For each patient the data available were joint type, age and gender. Knee samples chosen randomly among all biopsies were graded according to ICRS score. Patients' age ranged between 30 and 90 years with a mean age of 66 ± 9.7 years. Patients were divided into age classes and statistically significant differences in proliferation rate at passage 1 were found between chondrocytes derived from young and old donors, with the last ones characterized by a lower proliferation rate. A similar trend was observed for proliferation rate at passage 2. For all the samples, cellular yields ranged between 0.1 and 5.5 million cells/g of tissue. No significant correlation was observed between the level of cartilage degeneration (ICRS score) and cellular yield and proliferation rates. However, in samples with a high degree of cartilage degeneration (ICRS score 4) the cellular yield was lower compared to the other three groups (ICRS scores 1-3). In this study we performed a systematic characterization of basic parameters of chondrocytes originating from a wide group of OA patients. Considering the use of autologous chondrocytes in chondral treatments, the characterization of cell basic features may represent an important step to determine the quality of the cell source which is a major determinant in the outcome of cell-based therapies.

The following recommendations are based on expert opinions of an international multidisciplinary panel endorsed by the “European Federation of National Associations of Orthopaedics and Traumatology” (EFORT), the “European Hip Society” (EHS), the German “Arbeitsgemeinschaft Endoprothetik” (AE) and the “Deutsche Arthrosehilfe” (DAH)

Background Prosthetic joint infections (PJI) are still a major complication of hip and knee arthroplasties. Identification of the causative pathogens and knowledge of their antibiotic susceptibilities are essential for the management of these infections. The main purpose of the study was to identify and compare the causative bacteria of prosthetic knee and hip joint infections in a reference Italian orthopedic center and to characterize antibiotic resistance profiles of bacteria involved. Methods Data from 429 patients with diagnosis of PJI were collected from January 2013 to June 2015: 229 presented a hip and 200 a knee prosthesis infection. Prostheses and periprosthetic tissues were treated with dithiothreitol before plating onto different media and broths. Identification and antimicrobial susceptibility testing were carried out by VITEK2 Compact (bioMerieux). Results There was not a substantial difference in the etiology of hip and knee PJI: staphylococci were the most frequently isolated bacteria in both groups, followed by Enterobacteriaceae and Propionibacterium acnes . Staphylococci showed a high rate of methicillin resistance (144 of 341) and a worrying frequency of isolates were resistant to teicoplanin (9%). Only 8.3% of Enterobacteriaceae produced extended-spectrum beta-lactamases, whereas the rate of carbapenemase-producing bacteria was not significant. Conclusion We observed similar etiology of hip and knee PJIs. Nevertheless, bacteria isolated from knee showed higher resistance rates to glycopeptides and fluoroquinolones when compared with those isolated from the hip. The reason for this difference remains to be elucidated in future studies.

Dual mobility cups are getting increasing interest for the prevention, but also in the treatment of THA instability. Nevertheless when a dislocation occurs the main issue remains the knowledge and the correction of the causes of dislocation, including reorientation of the components and soft tissues treatment. There are several options of alternative implants to DMCs including upsizing of the head, and constrained liners. The Authors present how to evaluate patients with THA instability, the advantages and the disadvantages of each procedure and their experience in the treatment of cases without DMCs during a five years' time period.

There is no consensus on the bearing of choice in revision for ceramic fracture after total hip arthroplasty (THA). The aim of this study was to evaluate the outcomes using ceramic-on-polyethylene (CoP) articulation in revision for ceramic breakage. Twelve patients who underwent revision hip surgery between 2002 and 2013 were followed-up. Appropriate surgical technique, including accurate synoviectomy, was used. The cup and the head were changed in four patients and only the liner and the head were replaced in the remaining eight patients. At the final follow-up there were no cases of re-revision due to tribological reasons, and only one case of polyethylene (PE) wear and osteolysis was scheduled for a new revision because of clear cup malposition. Complications were four cases of dislocation, one case of loosening and one case of infection. Revision of fractured ceramic is a challenging situation with a high risk of early complications. Using CoP liners with accurate synoviectomy and correction of misalignment can be considered a valuable bearing option at medium-term follow-up.

Wound closure in primary and revision total hip arthroplasty is an essential and crucial step of the procedure. A recently published meta-analysis comparing metallic staples and sutures with stitches in hip procedures revealed that the risk of infection was four times greater when staples were used. This statement created concern among orthopaedic surgeons. The aim of this overview is to address the problem of THA wound closure and wound monitoring. Further well designed, randomised, controlled trials comparing staples vs traditional stitches and eventually vs skin adhesive are necessary in order to draw conclusions in elective THA, revision surgery and hip fractures. Orthopaedic surgeons need to have more evidence in order to be able to justify their method of wound closure. Monitoring of the wound by the surgeon in the postoperative period is recommended.

Grob et al. (Eur Spine J 5:281–285, 1996) illustrated a new fixation technique in inveterate cases of grade 2–3 spondylolisthesis (degenerative or spondylolytic): a fusion without reduction of the spondylolisthesis. Fixation of the segment was achieved by two cancellous bone screws inserted bilaterally through the pedicles of the lower vertebra into the body of the upper slipped vertebra. Since 1998 we have been using this technique according to the authors’ indications: symptomatic spondylolisthesis with at least 25% anterior slippage and advanced disc degeneration. Afterwards this technique was used also in spondylolisthesis with low reduction of the disc height and slippage less than 25%. In every case we performed postero-lateral fusion and fixation with two AO 6.5 Ø thread 16 mm cancellous screws. From 1998 to 2002 we performed 62 fusions for spondylolisthesis with this technique: 28 males (45.16%) and 34 females (54.84%), mean age 45 years (14–72 years). The slipped vertebra was L5 in 57 cases (92%), L4 in 2 cases (3.2%), L3 in 1 case (1.6%), combined L4 and L5 in 2 cases (3.2%). In all cases there was an ontogenetic spondylolisthesis with lysis. Lumbar pain was present in 22 patients and lumbar-radicular pain was present in 40 patients. The mean preoperative VAS was 6.2 (range 5–8) for lumbar pain, and 5.5 (range 4–7) for leg pain. The fusion area was L5–S1 in 53 cases (85.5%), L3–L4 in 1 case (1.6%), L4–S1 in 8 cases (12.9%). A decompression of the spinal canal by laminectomy was performed in 33 procedures (53%). When possible a bone graft was done from the removed neural arc, and from the posterior iliac crest in the other cases. The mean blood loss was about 254 ml (100–1,000). The mean operative time was 75 min (range 60–90). The results obtained by computerized analysis at follow-up at least 5 years after surgery showed a significant improvement in preoperative symptoms. The patients were asymptomatic in 52 cases (83.9%); strained-back pain was present in 8 cases (12.9%), and there was persistent lumbar-radicular pain in 2 cases (3.2%). The mean ODI score was 2.6%, the mean VAS back pain was 1.3, the mean VAS leg pain 0.7. Some complications were observed: a nerve root compression by a screw invasion of intervertebral foramen, resolved by screw removal; an iliac artery compression by a lateral exit screw from pediculo, resolved by screw removal; a deep iliac vein phlebitis with thrombosis caused by external compression due to a wrong intraoperative position, treated by medicine. Two cases of synthesis mobilization and two cases of broken screws was detected. No cases of pseudoarthrosis and immediate or late superficial or deep infection were observed. The analysis of the long-term results of the spondylolisthesis surgical treatment with direct pediculo-body screw fixation and postero-lateral fusion gave a very satisfactory response. The technique is reliable in allowing an optimal primary stability, creating the best biomechanical conditions to obtain a solid fusion.

The generation of functional, vascularized tissues is a key challenge for both tissue engineering applications and the development of advanced in vitro models analyzing interactions among circulating cells, endothelium and organ-specific microenvironments. Since vascularization is a complex process guided by multiple synergic factors, it is critical to analyze the specific role that different experimental parameters play in the generation of physiological tissues. Our goals were to design a novel meso-scale model bridging the gap between microfluidic and macro-scale studies, and high-throughput screen the effects of multiple variables on the vascularization of bone-mimicking tissues. We investigated the influence of endothelial cell (EC) density (3-5 Mcells/ml), cell ratio among ECs, mesenchymal stem cells (MSCs) and osteo-differentiated MSCs (1:1:0, 10:1:0, 10:1:1), culture medium (endothelial, endothelial + angiopoietin-1, 1:1 endothelial/osteo), hydrogel type (100%fibrin, 60%fibrin+40%collagen), tissue geometry (2 × 2 × 2, 2 × 2 × 5 mm(3)). We optimized the geometry and oxygen gradient inside hydrogels through computational simulations and we analyzed microvascular network features including total network length/area and vascular branch number/length. Particularly, we employed the "Design of Experiment" statistical approach to identify key differences among experimental conditions. We combined the generation of 3D functional tissue units with the fine control over the local microenvironment (e.g. oxygen gradients), and developed an effective strategy to enable the high-throughput screening of multiple experimental parameters. Our approach allowed to identify synergic correlations among critical parameters driving microvascular network development within a bone-mimicking environment and could be translated to any vascularized tissue.

Osteoarthritis is the most common degenerative disease of joints like the hip and the trapeziometacarpal joint (rhizarthrosis). In this in vitro study, we compared the chondrogenesis of chondrocytes derived from the trapezium and the femoral head cartilage of osteoarthritic patients to have a deeper insight on trapezium chondrocyte behavior as autologous cell source for the repair of cartilage lesions in rhizarthrosis. Chondrocytes collected from trapezium and femoral head articular cartilage were cultured in pellets and analyzed for chondrogenic differentiation, cell proliferation, glycosaminoglycan production, gene expression of chondrogenic and fibrous markers, histological and immunohistochemical analyses. Our results showed a higher cartilaginous matrix deposition and a lower fibrocartilaginous phenotype of the femoral chondrocytes with respect to the trapezium chondrocytes assessed by a higher absolute glycosaminoglycan and type II collagen production, thus demonstrating a superior chondrogenic potential of the femoral with respect to the trapezium chondrocytes. The differences in chondrogenic potential between trapezium and femoral head chondrocytes confirmed a lower regenerative capability in the trapezium than in the femoral head cartilage due to the different environment and loading acting on these joints that affects the metabolism of the resident cells. This could represent a limitation to apply the cell therapy for rhizoarthrosis.

In November 2015 the British Hip Society and the Italian Hip Society (Societa Italiana dell’Anca) combined to hold a first ever joint meeting. We had the privilege of co-chairing this and we have both reflected on the many positives that can be seen from combining intellects and experiences from

Bone-implant integration represents a major requirement to grant implant stability and reduce the risk of implant loosening. This study investigates the effect of progenitor cells and strontium-enriched hydrogel on the osseointegration of titanium implants. To mimic implant-bone interaction, an ectopic model was developed grafting Trabecular Titanium(™) (TT) implants into decellularized bone seeded with human bone marrow mesenchymal stem cells (hBMSCs). TT was loaded or not with strontium-enriched amidated carboxymethylcellulose (CMCA) hydrogel and/or hBMSCs. Constructs were implanted subcutaneously in athymic mice and osteodeposition was investigated with microcomputed tomography (micro-CT), scanning electron microscopy (SEM), and pull-out test at 4, 8, and 12 weeks. Fluorescence imaging was performed at 8 and 12 weeks, histology at 4 and 8 weeks. Micro-CT demonstrated the homogeneity of the engineered bone in all groups, supporting the reproducibility of the ectopic model. Fluorescence imaging, histology, SEM and pull-out mechanical testing showed superior tissue ingrowth in TT implants loaded with both strontium-enriched CMCA and hBMSCs. In our model, the synergic action of the bioactive hydrogel and hBMSCs increased both the bone deposition and TT integration. Thus, we suggest that using orthopedic prosthetic implant preloaded with strontium-enriched CMCA and seeded with BMSCs could represent a valid single-step surgical strategy to improve implant osseointegration.

Larger femoral heads are commonly presumed to improve joint stability and hip biomechanics; some studies have suggested they may hasten recovery of a normal gait. To our knowledge, no gait analysis studies have compared different size head diameters in THA.We compared (1) spatiotemporal gait parameters, (2) kinematic and kinetic gait parameters, and (3) Harris hip scores in patients undergoing THA randomized to receive a 28-, 36-, or ≥ 42-mm bearing couple. We hypothesized a larger femoral head would restore an earlier, more physiologic gait pattern.This randomized, blinded study involved 60 patients who received the same cementless THA except for the size of the bearing. Inclusion criteria were primary hip arthritis, female sex, and age between 55 and 70 years. Exclusion criteria were other problems influencing walking ability. The patients were randomized into three groups of 20 each (28- and 36-mm ceramic-on-crosslinked polyethylene, ≥ 42-mm metal-on-metal). All patients underwent the same postoperative rehabilitation protocol. Gait evaluation using an optoelectronic system was performed preoperatively and at 2 and 4 months postoperatively.With the numbers available, no differences in spatiotemporal gait parameters, kinematic or kinetic gait parameters, or Harris hip scores emerged among the three groups. All variables assessed at 4 months postoperatively showed improvements across all groups, but the differences among them were not significant.The hypothesis that a larger femoral head results in improved early gait performance was not supported by this study.

Insufficient implant stability is an important determinant in the failure of cementless prostheses. To improve osseointegration, we aim at generating a bioactive implant combining a macroporous titanium (TT) with a biocompatible hydrogel to encapsulate osteo-inductive factors and osteoprogenitor cells. Amidation and cross-linking degree of an amidated carboxymethylcellulose hydrogel (CMCA) were characterized by FT-IR spectrometry and mechanical testing. Bone marrow mesenchymal stem cells (BMSCs) from osteoarthritic patients were cultured on CMCA hydrogels, TT, and TT loaded with CMCA (TT + CMCA) with an optimized concentration of SrCl2 to evaluate cell viability and osteo-differentiation. Amidation and cross-linking degree were homogeneous among independent CMCA batches. SrCl2 at 5 μg/mL significantly improved BMSCs osteo-differentiation increasing calcified matrix (P < 0.01), type I collagen expression (P < 0.05) and alkaline phosphatase activity. TT + CMCA samples better retained cells into the TT mesh, significantly improving cell seeding efficiency with respect to TT (P < 0.05). BMSCs on TT + CMCA underwent a more efficient osteo-differentiation with higher alkaline phosphatase (P < 0.05) and calcium levels compared to cells on TT. Based on these in vitro results, we envision the association of TT with strontium-enriched CMCA and BMSCs as a promising strategy to generate bioactive implants promoting bone neoformation at the implant site. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 3396–3403, 2013.

Successful treatment of prosthetic joint infections often requires multiple surgical interventions and prolonged antibiotic therapy. However, in some specific situations surgical intervention can not be the treatment of choice. We refer to situations where there is no pain or impairment of the general conditions, involving patients, usually elderly, refusing surgery. In these cases we consider the conservative approach as an option.

The aim of this study is to evaluate the outcome of the cementless SL-Plus stem in worldwide arthroplasty register datasets.A structured analysis was conducted the registered data about the SL-Plus stem manufactured by SmithNephew including published data from Australia as well as previously unpublished datasets from the Registers of Lombardia, Italy and Valdoltra, Slovenia. A total of 75% of the data analysed had not been published so far. The primary outcome measure was the revision rate, calculated in revisions per 100 observed component years. We evaluated a total of 10,684 primary and 122 revision surgeries with an average follow-up period of four years.All datasets showed good and reproducible results for treatment with the SL-Plus stem. An average of 0.31 revisions per 100 observed component years had been reported, which is considerably below the worldwide average (1.29) found for total hip arthroplasty independent of the product. The results of a large centre did not essentially deviate from the revision rates in Lombardia, where the numbers of cases per department are relatively low on average.There were no indications for product defects or relevant errors in application. The SL-Plus stem can be considered a high-quality product that ensures good results also in the hands of less experienced surgeons. Data from even young registers can substantially contribute to the assessment of implants, even with the short follow-up periods. These datasets particularly allow for valid assessment of safety issues and can therefore make an essential contribution to the solution of problems of current relevance.

Summary Introduction There is an ongoing debate about the optimal use of metal-on-metal (MoM) bearings in total hip replacement, since there are uncertainties about local and systemic adverse effects due to wear and corrosion of these bearings. Despite various national recommendations, efforts to achieve international harmonization of specific evidence-based recommendations for best practice are still lacking. Hypothesis An international consensus study group should be able to develop recommendations on the use and monitoring of MoM bearings, preferably at the European level, through a multidisciplinary approach, by integrating the perspectives of various stakeholders. Materials and methods Twenty-one experts representing three stakeholder groups and eight countries participated in this European consensus study, which consisted of a consensus meeting, subsequent structured discussion, and consensus voting. Results The current statement defines first of all benefits, local and systemic risks, as well as uncertain issues related to MoM bearings. Safety assessment after implantation of MoM comprises all patients. A closer follow-up is recommended for large head MoM (≥ 36 mm) and resurfacing. In these implants basic follow-up should consist of x-rays and metal ion measurement of cobalt in whole blood, performed with GF-AAS or ICP-MS. Clinical and/or radiographic abnormality as well as elevated ion levels needs additional imaging (ultrasound, CT-scan and/or MARS-MRI). Cobalt values less than 2 μg/L are probably devoid of clinical concern, the threshold value for clinical concern is expected to be within the range of 2–7 μg/L. Discussion This is the first multinational, interdisciplinary, and multiprofessional approach for developing a recommendation for the use and monitoring of MoM bearings in total hip replacement. The current recommendations are in partial agreement with previous statements regarding the extent of follow-up and imaging techniques. They however differ from previous communications regarding measurement of metal ions and especially the investigated medium, technique, and eventual threshold levels. Level of evidence Level V, expert opinion/agreement conference.

To assess the effectiveness of indirect Magnetic Resonance arthrography (i-MRa) in the detection of chondral and labral lesions related to femoro-acetabular impingement (FAI) a series of 21 hip joints in 17 patients with a clinical diagnosis of FAI were examined either with standard MR imaging, i-MRa and direct-MR arthrography (d-MRa). Sensitivity and accuracy of i-MRa in detecting chondral, labral and tardive lesions were calculated and compared with standard MR. The agreement in detecting endoarticular damage between i-MRa and d-MRa and the interobserver agreement was assessed by K statistic (p