Breakage of exchangeable-neck (EN) and adverse local tissue reactions (ALTRs) to neck–stem junction (NSJ) damage products are responsible for increasing the revision rate of EN hip prostheses. We investigated the survivorship of an EN hip prosthesis including a NSJ with both components made of titanium alloy (Ti-alloy/Ti-alloy) to assess whether, and to what extent, EN breakage and NSJ damage affected implant survivorship. Using data from a hip replacement registry, we determined survivorship of 2857 EN prostheses. Long-offset configurations of head and EN were implanted in heavy (> 90 kg) patients only in 23 hips. We investigated under which conditions EN breakages or ALTRs occurred. We also measured titanium (Ti) and vanadium (V) blood concentrations in 24 patients with a unilateral well-working prosthesis. The 17-year survival rates for any reason and aseptic loosening of any component were 88.9% (95%CI 87.5–90.1; 857 hips at risk) and 96.9% (95%CI 96.0–97.6), respectively. There were two cases of EN breakage and one case of ALTR (metallosis), due to rim-neck impingement, out of 276 revisions. After an average period of 9.8 years (range 7.8–12.8 years), the maximum Ti and V blood concentrations in patients with a well-working prosthesis were 5.0 µg/l and 0.16 µg/l, respectively. The present incidence of EN breakage or ALTR is lower than those reported in other studies evaluating EN hip prosthesis survivorship. This study suggests that (i) the risk of EN breakage is reduced by limiting the use of long-offset configurations in heavy patients and (ii) Ti-alloy/Ti-alloy NSJ damage products do not promote ALTR nor significantly alter the rate of implant loosening. Since design decisions and implant configuration determine the NSJ strength, the NSJ strength in working conditions must be thoroughly investigated to proper define the clinical indications for any EN design.

Introduction: Noise in ceramic-on-ceramic (CoC) total hip arthroplasty (THA) is a potential symptom of abnormal bearing wear. Squeaking and other prosthetic hip noises are multi-factorial phenomena that can be analysed and may provide prognostic information. Methods: 46 patients with noisy CoC bearings were investigated using X-ray, computed tomography and joint fluid analysis, and classified into either high or low risk of ceramic liner fracture groups according to previously published guidelines. Noise events from the bearings of 16 high risk cases which were subsequently revised were compared with 30 patients in the low risk control group who did not undergo revision. Noise events were analysed for their physical characteristics using a standardised protocol and classified as either low frequency and short duration ‘clicking’ or long duration and high frequency ‘squeaking’. Results: The peak frequency of squeaking during forward walking was significantly higher for patients in the case group who were revised, compared with the control group. The patient-reported onset of squeaking (46 months postoperatively) was earlier than short-noise emissions (82 months). In the standardised sequence of movements, short-noise always occurred more frequently than squeaking. Small heads (28 mm) were more likely to develop short-noise, while large heads (⩾32 mm) were more likely to develop squeaking. Discussion: Noise evaluation may provide additional value for predicting failure of CoC bearings, though some questions should be better investigated in a dedicated prospective trial.

Despite the encouraging short- and medium-term clinical results and increased usage of reverse shoulder replacements, a higher revision rate is documented compared with other major joint arthroplasties. Adverse reaction to polyethylene wear debris is still an important factor which may influence the long-term survival of reverse shoulder arthroplasty. To date, only a small number of retrieval studies of reverse shoulder arthroplasty have reported the different damage modes on polyethylene components, but none have quantified the ex vivo surface roughness on both articulating surfaces. The main purpose of this study was to assess, for the first time, the surface roughness of 13 retrieved metal-on-polyethylene reverse shoulder replacements using a white light profilometre with nanometre resolution. Although no significant relationship was observed between the surface roughness values and patient variables, it was noted that half of the polyethylene components still showed their original machining marks, indicating little change in vivo and that the metallic humeral components in the reversed design configuration showed low values of surface roughness after their time in vivo.

INTRODUCTION:Ceramic-on-ceramic couplings demonstrated to be reliable bearings in primary total hip arthroplasty (THA), with long-term remarkable results. Like-on-like configurations were widely described. On the contrary, mixed material combinations from the same manufacturer, Delta-on-Forte or Forte-on-Delta, were poorly studied. In particular, it is unknown whether mixed ceramic combinations are more at risk of ceramic fractures. Thus, a registry study was conducted to investigate the long-term survival rates and reasons for revision of mixed ceramic combinations. A comparison with Delta-on-Delta couplings was also performed.MATERIALS AND METHODS:The regional arthroplasty registry RIPO was enquired about three cohorts of ceramic bearings (head-on-liner: Delta-on-Forte, Forte-on-Delta, Delta-on-Delta). Demographics, survival rates and reasons for revision were evaluated and compared.RESULTS:In total, 346 (1.5%) implants had a Delta-on-Forte coupling (mean follow-up: 6.4 years). In total, 1163 (5%) THAs had a Forte-on-Delta articulation (mean follow-up: 8.2 years). Delta-on-Delta surfaces were implanted in 21,874 (93.5%) hips (mean follow-up: 3.9 years). Mixed material combinations were implanted between 2003 and 2007. The survival rates of the three cohorts were similar and were higher than 95% at 10 years. In Forte-on-Delta group, four liners failed (0.3% of the implants), whereas ceramic fractures occurred in 15 cases (0.1%) in Delta-on-Delta couplings (3 heads and 12 liners). Considering ceramic fracture as endpoint, there was no significant difference between the three survival rates.CONCLUSIONS:Mixed ceramic bearing configurations from the same manufacturer in primary THA showed mid-to-longterm dependable outcomes, not inferior to the most recent like-on-like ceramic bearings. No additional risks of ceramic fractures were evident. Thus, closer follow-ups are not required.

Background: Fourth-generation ceramic-on-ceramic couplings were developed to improve ceramic toughness and strength. Encouraging outcomes in primary total hip arthroplasty were reported. This coupling was proposed as an attractive option even in the case of revision procedures, particularly in younger patients with a longer life expectancy. However, the pertinent literature is scarce. Thus, a registry study was conducted to investigate the midterm survival rates and reasons for re-revision of the fourth-generation ceramic-on-ceramic bearing surfaces in revision hip arthroplasties. Methods: A total of 327 revision implants (all the components were exchanged) with BIOLOX Delta couplings were investigated using the regional orthopedic registry RIPO. The demographics, the survival rates, and the reasons for re-revision were assessed. Revisions with bearings other than Delta were compared. Results: Delta bearings achieved a survival rate of 90.5% at 7 years, with stable results. Twenty-six (8%) re-revisions occurred at a mean follow-up of 4.1 years. And 2.8% of the re-revisions were due to recurrent dislocations; 1.5% of the cases were due to cup aseptic loosening. Septic loosening occurred in 1.6% of the cases. No ceramic fractures were reported. When compared to revisions with bearings other than Delta-on-Delta, Delta coupling cohort achieved similar performances at 5 and 7 years. Lower, nonsignificant rates of aseptic and septic loosening were reported in Delta cohort. Conclusion: Delta-on-Delta couplings demonstrated to be reliable bearing surfaces in revision settings at a midterm follow-up. Clinical studies and longer follow-ups are required to investigate potential adverse effects, like squeaking and fractures, and confirm these preliminary findings. (C) 2019 Elsevier Inc. All rights reserved.

Background: Body mass index is used by the World Health Organization to classify obesity. While obesity influences the onset of arthritis and type-2 diabetes, its effect on implant survival is still open to debate, with conflicting results from clinical and registry studies, as well as meta-analyses. Other known factors such as gender or diabetes status could ponderate or mask the effect of BMI on implant survival. Hypothesis: Our hypothesis was BMI influenced hip and knee arthroplasty survival, when results were made independent of gender and diabetes status. Patient and methods: A registry study was designed on 30733 Total Hip Arthroplasties (THA), 28483 Total Knee Arthroplasties (TKA), 3754 Uni compartmental Knee Arthroplasties (UKA) and 649 Hinged Knee arthroplasties (HK), from 01/01/2003 to 31/12/2015. Mean follow-up was 5.5 years. Diabetes status was added to the model. Each arthroplasty survival was tested for age at implantation, gender, diabetes status, implant characteristics and specifically BMI, taking into account gender and diabetes status. Results: Gender had a strong influence on arthroplasty results. Age also influenced arthroplasty survival, especially aseptic loosening; a young age would lower implant survival. Diabetes had an influence in hip survival, but its influence on septic loosenings in TKA wasn't proven (p = 0.065). A mobile liner and/or a cruciate retaining knee were factors increasing the risk of revision. Weight influenced THA survival, especially aseptic loosening, but didn't have a measurable effect in any other arthroplasty. BMI was not found to influence any arthroplasty survival, whatever the endpoint, when diabetes and gender were taken into account. Discussion: Gender, age and diabetes influenced survival of the lower limb arthroplasties, whereas BMI did not. Only weight did influence THA results and should be used instead of BMI. Conclusion: Studies on arthroplasty survival should systematically mention gender and diabetes status and beware of potential group incomparability. (C) 2019 Elsevier Masson SAS. All rights reserved.

The purpose of this paper is to determine the prevalence of metal-on-metal (MoM) total hip replacement (THR) in European registries, to assess the incidence of revision surgery and to describe the national follow-up guidelines for patients with MoM THR including resurfacings.Eleven registries of the Network of Orthopaedic Registries of Europe (NORE) participated totalling 54 434 resurfacings and 58 498 large stemmed MoM THRs.The resurfacings and stemmed large head MoM had higher pooled revision rates at five years than the standard total hip arthroplasties (THA): 6.0%, 95% confidence interval (CI) 5.3 to 6.8 for resurfacings; 6.9%, 95% CI 4.4 to 9.4 for stemmed large head MoM; and 3.0%, 95% CI 2.5 to 3.6 for conventional THA.The resurfacings and stemmed large head MoM had higher pooled revision rates at ten years than the standard THAs: 12.1%, 95% CI 11.0 to 13.3 for resurfacings; 15.5%, 95% CI 9.0 to 22 for stemmed large head MoM; and 5.1%, 95% CI 3.8 to 6.4 for conventional THA.Although every national registry reports slightly different protocols for follow-up, these mostly consist of annual assessments of cobalt and chromium levels in blood and MRI (MARS) imaging. Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180078.

L’indice de masse corporelle (IMC) est utilisé par l’Organisation mondiale de la santé pour classer l’obésité. Bien que l’obésité influence l’apparition de l’arthrose et du diabète de type 2, son effet sur la survie des implants fait encore l’objet de débats, les résultats contradictoires d’études cliniques et d’études de registre, ainsi que de méta-analyses, étant non concluants. D’autres facteurs connus, tels que le sexe ou le statut diabétique pourraient pondérer ou masquer l’effet de l’IMC sur la survie des implants. Notre hypothèse était que l’IMC influençait la survie de l’arthroplastie de la hanche et du genou, lorsque les résultats étaient rendus indépendants du sexe et du statut diabétique. Une étude de registre a été conçue sur 30 733 prothèses totales de hanche (PTH), 28 483 prothèses totales du genou (PTG), 3754 prothèses uni-compartimentales de genou (PUC) et 649 prothèses charnières de genou (PC), du 01/01/2003 au 31/12/2015. Le suivi moyen était de 5,5 ans. L’état diabétique a été ajouté au modèle. Chaque survie d’implant a été testée en fonction de l’âge au moment de l’implantation, du sexe, de l’état diabétique, des caractéristiques de l’implant et plus particulièrement de l’IMC, en tenant compte du sexe et du statut diabétique. Le sexe avait une forte influence sur les résultats de l’arthroplastie. L’âge influençait également la survie de l’arthroplastie, en particulier sur la survie pour descellement aseptique ; un jeune âge diminuerait la survie de l’implant. Le diabète avait une influence sur la survie de la hanche, mais son influence sur le descellement septique des PTG n’a pas été prouvée (p = 0,065). Un plateau rotatoire et/ou une prothèse de genou avec conservation du LCP étaient des facteurs qui augmentaient le risque de révision. Le poids a influencé la survie de la PTH, en particulier vis-à-vis du descellement aseptique, mais n’a pas eu d’effet mesurable dans aucune autre arthroplastie. L’IMC n’a pas eu d’influence sur la survie de l’arthroplastie, quel que soit le critère d’évaluation, lorsque le diabète et le sexe étaient pris en compte. Le sexe, l’âge et le diabète influençaient la survie des arthroplasties des membres inférieurs, mais pas l’IMC. Seul le poids a influencé les résultats de la PTH et devrait être utilisé préférentiellement, au lieu de l’IMC. Les études sur la survie des arthroplasties devraient systématiquement mentionner le sexe et l’état diabétique et se méfier de l’incomparabilité potentielle des groupes. III, étude de cohorte.

BACKGROUND:In ceramic-on-ceramic (CoC) total hip arthroplasty (THA), component positioning demonstrated to influence the bearing damage: however the connection between angles and clinical outcomes at long-term follow-ups is currently lacking. Aims of this study were: the computer tomography (CT) assessment of component positioning in CoC THAs; the correlation analysis between positioning and ceramic damage; the identification of safe zones. METHODS:91 consecutive post-operative CT scans including two types of CoC implants, with a mean follow-up of 12 ± 4.4 years, were evaluated. III generation (74.2%) and IV generation (25.8%) CoC surfaces were included. The angle measurements (cup abduction, anteversion, cup tilt, stem antetorsion, sacral slope) were automated using a CT-based software. The combined anteversion was assessed as well as the cup-neck position at -15°, 0°, 45° and 90° of flexion. Ceramic damage was diagnosed using synovial fluid analyses and radiological criteria. RESULTS:63.7% of THAs was inside the cup abduction target 30°-45° and 68.1% was inside the cup anteversion target 5°-25°. 19 patients (20.9%) showed signs of ceramic damage. High cup abduction and high cup-neck 45° minimum angle (which stood for high abduction and extreme combined version) significantly correlated with ceramic damage. No demographical features apart III generation ceramic bearings influenced the results. No safe zones could be detected. CONCLUSIONS:In CoC THA, no safe zones can be described. However it is important to avoid cup inclination over 45° and a combination of steep cup and extreme combined version.

Background: Bilateral cases, representing at least 25% of total knee arthroplasties (TKA), could convey a statistical bias linked to dependency. Registries allow exploring this issue, susceptible to question surgeon validated protocols. Do bilateral total knee arthroplasties behave differently than unilateral knees in terms of implant survival? Hypothesis: Bilateral TKA have a better survival than unilateral TKA. Patients and methods: A number of 14,652 bilateral and 27,440 unilateral TKAs were compared. Influencing factors were tested with hazard ratios applied on bilateral knees. Results: Bilateral knees had a better survival (p < 0.001). Delay between first and second side surgeries had an influence on survival of the first knee: if below a year, the first knee survival was superior to the second knee; more than three years between both arthroplasties significantly decreased the survival of the first implant. If the first knee was revised, the hazard ratio for revision of the second implant was 3.5. Discussion: Series should include separate evaluations of bilateral cases, because they have a better survival than unilateral knees. A long delay between both knee replacements could impact both implant survivals. (C) 2019 Elsevier Masson SAS. All rights reserved.

Bilateral cases, representing at least 25% of total knee arthroplasties (TKA), could convey a statistical bias linked to dependency. Registries allow exploring this issue, susceptible to question surgeon-validated protocols. Do bilateral total knee arthroplasties behave differently than unilateral knees in terms of implant survival? Bilateral TKA have a better survival than unilateral TKA. A total of 14,652 bilateral and 27,440 unilateral TKAs were compared. Influencing factors were tested with hazard ratios applied on bilateral knees. Bilateral knees had a better survival (p < 0.001). Delay between first and second side surgeries had an influence on survival of the first knee: if below a year, the first knee survival was superior to the second knee; more than three years between both arthroplasties significantly decreased the survival of the first implant. If the first knee was revised, the hazard ratio for revision of the second implant was 3.5. Series should include separate evaluations of bilateral cases, because they have a better survival than unilateral knees. A long delay between both knee replacements could impact both implant survivals. III, cohort comparative study.

Background: Ischemia-modified albumin (IMA) derives from naive albumin, modified in the binding region of bivalent ions, as cobalt and iron. The cobalt, released from some types of hip prosthesis seems to be metabolized differently in males and females but the iron ion is more prevalent than cobalt and is detectable in the healthy population. Our aim was to verify if there are any gender-and age-related differences in IMA concentrations and if IMA correlates with cobalt and iron-related proteins. Methods: IMA, albumin, iron, ferritin, transferrin, and cobalt were measured in 50 men and 50 women divided into two age/fertility-homogeneous groups. Results: Men < 45-years-old showed a statistically significant lower IMA concentration than men >= 45 and fertile and menopausal women. Considering all the population studied, IMA does not seem to be correlated with age and is distributed differently by gender; also, Co distribution was different between males and females. Conclusions: IMA did not correlate with cobalt, iron, ferritin, and transferrin in any group, except for fertile women where IMA presented a statistically significant correlation with serum iron values. Minor expression of IMA in young males together with the results obtained on serum iron in fertile females, could explain the higher accumulation of circulating Co in women compared to men and their different cobalt metabolism.

Modular femoral stems for total hip arthroplasty (THA) were introduced to allow additional options for surgeons in controlling leg lengths, offset and implant stability. This option is widely used in our Region, where the study was conducted, having a modular neck stem nearly 35% of primary THA in 2013. Great majority of modular neck is made of Titanium alloy.The study was designed as a retrospective descriptive case series of 67 hips in patients who underwent revision of a THA. All had a Titanium modular neck. In 44 cases revision was due to breakage of the neck, in the remaining 23 it was due to different reasons unrelated to modular neck such as bone fracture, breakage of a ceramic component, cup loosening.Mean follow up was 3.5 yrs. For all patients excised capsule and surrounding tissue were graded for presence of necrosis, inflammatory exudate, lymphocytes, and wear particles using light microscopy of routine paraffin sections stained with hematoxylin and eosin. The retrieved modular neck-body and h...

PURPOSE:Periprosthetic hip infection (PHI) is a devastating complication. The association between PHI and bearing surfaces as well as patient-related factors has been recently investigated, with contradictive outcomes. The dataset of Emilia-Romagna region Registry for Orthopaedic Prosthetic Implants (RIPO) has been assessed to investigate, if the bearing choice influenced the risk of septic loosening occurrence.METHODS:RIPO data about 39,206 cementless total hip arthroplasties (THA), collected since 2003, were analysed. Age, gender, BMI, diabetes and bearing surfaces were evaluated. The end point of the study was the revision of at least a single component due to sepsis.RESULTS:Adjusted and unadjusted survival rates showed that ceramic-on-ceramic (COC) implants had the lower incidence of PHIs, whereas metal-on-metal (MOM) THAs were significantly more prone to infection. In MOM cohort, stemmed implants were involved in 28 out of 30 cases. Among the demographical features and comorbid conditions, only diabetes statistically influenced the rate of sepsis.CONCLUSIONS:Bearing surfaces influenced the rate of PHI; in particular, stemmed MOM implants were at higher risk, probably due to metal debris consequent to taperosis. Despite the preliminary results, stemmed MOM THAs should be used with care, and diabetic patients should be warned about increased septic risks.

Background: Short stems in total hip arthroplasty (THA) have recently gained increasing popularity, allowing mini-invasive exposures and bone-sparing approaches. However, long-term studies and recommendations for the routine use are not available. The aim of this report was to compare the survival rates and the reasons for revision of short stems versus conventional stems in cementless THAs, in a registry-based population. Methods: The Registry of Prosthetic Orthopedic Implants (RIPO) was inquired about cementless THAs performed since 2000 to 2016. The stems were divided into short (<12 cm) and conventional ones, and then, classified according to the classification by Feyen and Shimmin: short stems with neck-retaining osteotomy (group A: 1684 hips), short stems with standard osteotomy (group B: 2727 THAs), and conventional stems (group C: 57,359 cases). Demographics, survivorships, and reasons for revision were investigated and compared. Results: Short stems were preferentially implanted in younger patients and normal morphologies. Short and conventional stems showed comparable survival rates at long-term follow-up (>90% at 15 years). The rates of stem aseptic loosening, intraoperative fractures, and periprosthetic fractures were similar in the 3 groups. Group B had higher rates of revisions due to primary instability (early dislocations and impingement-related events; P < .05). Revisions due to pain were nonsignificantly higher in group B. Conclusion: Short stems are reliable implants at long-term follow-up. The comparison with conventional stems showed no additional risk of premature aseptic loosening and intraoperative and periprosthetic fractures. However, the high rate of revisions due to pain and, mostly, primary instability should be investigated in clinical trials. (C) 2018 Elsevier Inc. All rights reserved.

Ceramic-on-ceramic (CoC) total hip arthroplasty (THA) can produce articular noise during the normal activities, generating discomfort to the patient. THA noise has to be investigated also as a potential predictor and a clinical sign of prosthetic failure. An observational study has been carried out to characterize the noise in CoC cementless THA, and to analyze the related factors. A total of 46 patients with noisy hip have been enrolled in 38 months, within the follow-up protocol normally applied for the early diagnosis of ceramic liner fracture [1]. Noise recording was based on a high-quality audible recorder (mod. LS 3, Olympus, Japan) and a portable ultrasonic transducer (mod USB AE 1ch, PAC, USA). The sensors for noise recording were applied to the hip of the patient during a sequence of repeatable motorial activities (forward and backward walking, squat, sit in a chair, flexion and extension of the leg). Sessions were also video-recorded to associate the noise emission to the specific movements. Each noise event was initially identified by the operator and therefore classified by comparison to the spectral characteristics (duration, intensity and frequency) of the main noise types. Number and spectral characteristics of noise events were obtained and correlated to the factors describing the clinical status of the patient, the surgical approach, the prosthetic device implanted. The study investigated also the noise as a sign of implant failure, by comparison with the total number of implants failed in the cohort during the study. We observed three types of noise with the main spectral characteristics in agreement to the literature: clicking, squeaking and popping. Among the identified types of noise, squeaking showed the longest duration and the highest amplitude. The 63% of hip presented the emission of just one type of noise, while the remaining a mix of types. The movement with the highest presence of noise was walking, followed by squat. Correlation was found between the noise type and the dimension of the ceramic head (p The study presented and validated an experimental procedure to analyze noisy hips in clinical trials. Noise is confirmed to be a significant parameter in the follow-up evaluation of ceramic THA.