The role of metal sensitivity or allergy in causing persistent symptoms or failure and need for a revision of a total joint replacement has been the topic of debate and controversy for decades. There was renewed interest in this area with the rise of metal-on-metal hip arthroplasty and the advent of adverse local tissue reactions. This led to an increase in metal ion testing as well as metal sensitivity testing. With the decline of the use of metal-on-metal hip components, this is now mostly an issue in knee arthroplasty. It is well known that a substantial percentage of patients have persistent symptoms following knee replacement. What remains in question is whether allergy to metal or other materials such as PMMA may be a contributing factor. It is accepted that the incidence of positive skin patch tests is higher in symptomatic failed joint replacements. Nickel sensitivity is most common as a positive skin test with up to 15% of patients demonstrating this followed by chromium and cobalt. A recent review by Lachiewicz et al. concluded that there was insufficient evidence to recommend routine or widespread cutaneous or in vitro hypersensitivity testing before primary TKA, that there is no evidence-based rationale to recommend a routine metal allergy screening questionnaire, that there is only anecdotal support for Ni-free implants, and that local dermatitis should be treated with topical steroids. In another article, routine screening for metal allergy was not recommended, however, selective screening for history of sensitivity or unexplained pain or early loosening was suggested. Other experts have recommended a role for utilizing a commercially available alternative to components containing nickel or cobalt in patients thought to be hypersensitive. A recent study, however, concluded that there was no difference in complications, revisions, or reoperations among patients who tested positive with patch testing whether they were treated with standard components or nickel free components. Likewise, a consensus panel published results from the United Kingdom in which cobalt chrome implants were recommended regardless of the patients metal allergy status. Patient perception is important, however, and among patients who report multiple allergies of any kind, a higher percentage are likely to be dissatisfied with their knee replacement. Of more importance are those reporting a specific allergy to metal are substantially more likely to express some dissatisfaction with their components. Metal allergy as a cause of chronic pain and/or early failure of joint replacement is rare if it exists at all. It is always a diagnosis of exclusion. Patients who think they are allergic are probably more likely to be more symptomatic following joint replacement. Whether or not to use a nickel free or hypoallergenic component in such patients remains an area of controversy

Developmental dysplasia of the hip (DDH) refers to a spectrum of anatomical abnormalities. Despite various screening programs, delayed diagnosis still occurs. Delayed cases are more difficult to treat and can have poorer outcomes. Rural address, low socioeconomic status, and ethnicity have recently been associated with late presentation. The objectives of this study were to examine the incidence of DDH, as well as factors associated with delayed presentation in Saskatchewan. Retrospective review of paediatric orthopaedic records from the tertiary referral centre in Saskatchewan was completed from 2008–2014. Variables collected included age at presentation, sex, birth order, birth presentation, birth complications, laterality, family history of DDH, postal code and treatment. Socioeconomic and geographic indicators were determined from postal code using the 2011 National Household Survey. Population level variables included income, ethnic origin, distance from referral centre and education. Associations were examined with bivariate and multivariate analysis. There were 108 new presentations of DDH; 34 cases presented after age 3 months. Demographic data showed 83.3% of cases were female, 48.1% involved the left hip, 17.2% had a positive family history, 57.1% were first born, and 27.9% were breech. An estimated 5.6% of patients were Aboriginal. The mean age at presentation was 199.7 days. 48% of cases lived in the same city as the referral center. Late presenting cases lived on average 46.19 km farther from the referral centre and had a lower mean population, percent of adults with post-secondary education and income. However, none of these were statistically significant. No significant associations were found within the demographic data. Overall incidence of DDH was not estimated due to few cases from southern areas of the province presenting to the tertiary referral center. The estimated incidence of DDH in the Aboriginal population from our sample was lower than previously reported in the literature. This association may be related to earlier swaddling practices, rather than Aboriginal ethnicity. There was a trend toward lower socioeconomic indicators and an increased distance from the referral centre in cases of late presentation, in keeping with recent literature exploring these factors. This suggests there may be deficits in the current selective screening protocols in North America. The study is limited by the retrospective nature of the research and the population level data obtained for certain variables. Future research to collect prospective individual level data may help elucidate important associations. Also, identifying any additional cases would increase the power to detect significant associations with late presentation, and allow an accurate estimate of overall incidence

Aims. We investigated the local epidemiology of Developmental Dysplasia of the Hip (DDH), in order to define incidence, identify risk factors, and refine our policy on selective ultrasound screening. Methods. Data were recorded prospectively on all live births in the Exeter area from January 1998 to December 2008. We compared those treated for DDH with all other children. Crude odds ratios (OR) were calculated to identify potential risk factors. Logistic regression was then used to control for interactions between variables. Results. There were 182 children with DDH (245 hips) and 37,051 without. The incidence was thus 4.9 per 1000 live births. Female sex (adjusted OR 7.2, 95% CI 4.6-11.2), breech presentation (adjusted OR 24.3, 13.1-44.9), positive family history (adjusted OR 15.9, 11.0-22.9) and first or second pregnancy (adjusted OR 1.8, 1.5-2.3) were confirmed as risk factors (p<0.001). In addition, there was an increased risk with vaginal delivery (adjusted OR 2.7, 1.6-4.5, p<0.001) and postmaturity (OR 1.7, 1.2-2.4, p<0.002). Conclusions. One in 200 children born in our area requires treatment for DDH. Using both established and novel risk factors, we can potentially calculate an individual child's risk. Our work may contribute to the debate about selective versus universal ultrasound screening

Aim. The aim of this study is to assess the effectiveness of clinic based ultrasound screening by Orthopaedic surgeon for early diagnosis and treatment of developmental dysplasia of hip (DDH) in one stop clinic. Methods. This prospective study included 395 infants (185 male and 210 female) (5.2% of study population) who were referred for screening on the basis of abnormal findings or the presence of risk factors for DDH. Average age was 12.5 weeks (1 day to 15 months). All infants were assessed for risk factors of DDH. Clinical examinations were performed by the senior author followed by ultrasonography of both of the infant's hips, using the Graf's technique. Alpha and beta angles were calculated and hips were classified according to Graf's classification system. Results. Out of 790 hips examined 670 (84.8%) were labelled as normal. 120 (15.1%) hips in 84 patients were diagnosed as dysplastic or dislocated. Clinical examination only detected 39 patients out of 84, sensitivity of 46%. Average age of diagnosis was 12 weeks (3days-11 months). 79 patients were successfully treated with pavlic harness, 2 required traction and 3 were referred for surgical treatment. There were 14 cases of late diagnosis during one year period (> 4 months of age) (1.8/1000). Conclusion. Selective ultrasound screening is effective in early diagnosis of DDH and significantly reduces the duration of non operative treatment as well as the need for surgical intervention but does not completely eliminate late diagnosis of DDH. We find the concept of one stop DDH clinic highly effective and recommend that ultrasound training should be a part of orthopaedic curriculum