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.

Avascular necrosis of the femoral head (AVN) is associated with collapse of the femoral head and arthritic degeneration of the joint. The combination of an implant inserted into the femoral head that provides mechanical support and bone grafting to promote bone formation may offer a possible joint-preserving solution1. Seventeen such procedures were performed between November 2012 and March 2014 during an IRB approved clinical trial. Thirteen out of 18 patients remained unrevised at a minimum of 12 months; the results of radiographic and histological analysis of four revisions are presented.

The investigational device (Figure 1) was developed as a joint preserving treatment for AVN with a clinical grade of IIC or less according to the ARCO grading system2.

The device consisted of a braided spherical Nitinol cage with a Titanium / Nitinol orientation feature. It was implanted using fluoroscopic navigation into a spherical cavity cut into the femoral head via an 11mm diameter access tunnel. Once deployed, the implant was filled with a lightly impacted mixture of autologous bone graft and bone marrow soaked Conduit TCP (DePuy CMW, Blackpool, UK). The implant's purpose was to provide mechanical support to the weakened subchondral surface while the bone graft mixture re-integrated with the host bone.

The retrieved femoral heads were trimmed to leave approximately 3mm of bone around the implant, dehydrated, embedded in methacrylate resin, sectioned and thinned into 50–70µm coronal slices for histological analysis. The following observations were made (Figure 2):

Case 1 (Female, age 70, ARCO IIB, revised after 2 days): The patient was revised for spontaneous sub-trochanteric fracture secondary to osteoporosis. Contact between the native bone and bone graft was observed. Marrow elements and repair tissue were visible within the pores in the graft (Figure 2a).

Case 2 (Male, age 67, ARCO IIIC, revised after 82 days): Two wires were broken but retained within the braided structure. A radiolucent gap caused by the presence of fibrous tissue between the graft mixture and native bone was evident suggesting that the implant was unable to prevent progression in this case.

Case 3 (Female, age 70, ARCO IIC, revised after 482 days): The cavity penetrated the subchondral surface; at revision the implant was found to have breached the articular cartilage. There was partial separation of the proximal osteonecrotic fragment and no evidence of graft revascularisation or remodelling within the implant.

Case 4 (Male, age 42, ARCO IIC, revised after 469 days): There was no indication of bone graft re-integration. Collapse of the necrotic bone and deformation of the implant was diagnosed from 1 year follow-up x-rays.

Purpose

Antibiotic prophylaxis plays an important role in minimizing surgical site infections as well as other nosocomial peri-operative infections in orthopaedic trauma patients. Pre-operative prophylaxis has been shown to be efficacious, but the role and duration of post-operative prophylaxis remains controversial. The goal of this study was to assess whether patients receive their antibiotic prophylaxis as prescribed. What dose and duration of antibiotics are typically ordered, what patients actually receive, and factors causing the ordered antibiotic regime to be altered were also investigated. This study did not investigate infection rates or the efficacy of various antibiotic prophylactic regimes.