Introduction. Trabecular Titanium is a biomaterial characterized by a regular three-dimensional hexagonal cell structure imitating trabecular bone morphology. Components are built via Electron Beam Melting technology in aone- step additive manufacturing process. This biomaterial combines the proven mechanical properties of Titanium with the elastic modulus provided by its cellular solid structure (Regis 2015 MRS Bulletin). Several in vitro studies reported promising outcomes on its osteoinductive and osteoconductive properties: Trabecular Titanium showed to significantly affect osteoblast attachment and proliferation while inhibiting osteoclastogenesis (Gastaldi 2010 J Biomed Mater Res A, Sollazzo 2011 ISRN Mater Sci); human adipose stem cells were able to adhere, proliferate and differentiate into an osteoblast-like phenotype in absence of osteogenic factors (Benazzo 2014 J Biomed Mater Res A). Furthermore, in vivo histological and histomorphometric analysis in a sheep model indicated that it provided bone in-growth in cancellous (+68%) and cortical bone (+87%) (Devine 2012 JBJS). A multicentre prospective study was performed to assess mid-term outcomes of acetabular cups in Trabecular Titanium after Total Hip Arthroplasty (THA). Methods. 89 patients (91 hips) underwent primary cementless THA. There were 46 (52%) men and 43 (48%) women, with a median (IQR) age and BMI of 67 (57–70) years and 26 (24–29) kg/m2, respectively. Diagnosis was mostly primary osteoarthritis in 80 (88%) cases. Radiographic and clinical evaluations (Harris Hip Score [HHS], SF-36) were performed preoperatively and at 7 days, 3, 6, 12, 24 and 60 months. Bone Mineral Density (BMD) was determined by dual-emission X-ray absorptiometry (DEXA) according to DeLee &Charnley 3 Regions of Interest (ROI) postoperatively at the same time-points using as baseline the measureat 1 week. Statistical analysis was carried out using Wilcoxon test. Results. Median (IQR) HHS and SF-36 improved significantly from 48 (39–61) and 49 (37–62) preoperatively to 99 (96–100) and 76 (60–85) at 60 mo. (p≤0.0001). Radiographic analysis showed evident signs of bone remodelling and biological fixation, with presence of superolateral and inferomedial bone buttress, and radial trabeculae in ROI I/II. All cups resulted radiographically stable without any radiolucent lines. The macro-porous structure of this biomaterial generates a high coefficient of friction (Marin 2012 Hip Int), promoting a firm mechanical interlocking at the implant-bone interface which could be already observed in the operating room. BMD initially declined from baseline at 7 days to 6 months. Then, BMD slightly increased or stabilized in all ROIs up to 24 months, while showing evidence of partial decline over time with increasing patient' age at 60 months, although without any clinical significance in terms of patients health status or implant stability. Statistical significant correlations in terms of bone remodeling were observed between groups of patients on the basis of gender and age (p≤0.05). No revision or implant failure was reported. Conclusions. All patients reported significant improvements in quality of life, pain relief and functional recovery. Radiographic evaluation confirmed good implant stability at 60 months. These outcomes corroborate the evidence reported on these cups by orthopaedic registries and literature (Perticarini 2015 BMC Musculoskelet Disord; Bistolfi 2014 Min Ortop)

Purpose. Traditional recommendations suggest that open fractures require urgent surgical debridement to reduce infection. Although many papers comparing early vs late debridement have found no difference in infection rates, these papers have not taken into account important confounding factors. We attempt to answer whether delay between injury and surgical debridement in open fractures is associated with a higher infection rate after accounting for these important confounders. Method. Five hundred and twenty three open extremity fractures in 417 patients were identified using the Sunnybrook trauma and orthopaedic department registries. Thirty patients (36 fractures) did not have complete follow-up. Seven patients were excluded due to incomplete data (complete follow-up rate=91%). A further 14 patients died during their hospitalization. A total of 459 fractures in 364 patients were reviewed. Data was collected on demographics, ISS score, ASA, time to initial operative debridement, timing of antibiotic administration, mechanism of injury, presence of significant contamination, and Gustillo-Anderson fracture grade. Deep infection was defined as an unplanned return to the operating room for treatment of infection. The influence of time to initial debridement was examined in an unadjusted analysis as a continuous variable and at thresholds of 6 and 12 hours of delay. A multivariable logistic regression was used to analyze the effect of delay while controlling for important confounding variables. Results. 46 deep infections occurred in 459 fractures (10%). In an unadjusted analysis, infection was associated with male sex(p=0.038), higher fracture grade(p=0.007), tibial fractures(p=0.027) and gross contamination (p=0.0001). In an unadjusted analysis, delay to debridement was not associated with deep infection (p=0.08) however, higher grade fractures, tibial fractures and grossly contaminated fractures were debrided earlier than less severe open fractures. Multivariable analysis showed infection was associated with each additional hour of delay (OR=1.033 95%CI 1.01 to 1.057), tibial fractures (OR=2.44 95%CI 1.26 to 4.73), higher Anderson & Gustillo grade (OR=1.99 95%CI 1.004 to 3.954), and gross contamination (OR=3.12 95%CI 1.36 to 7.36). Conclusion. Among more severe open fractures the impact of delay to debridement translates into a larger absolute increase in probability of infection. For example, a grade 2 injury of the forearm without contamination will have a predicted infection rate increase from 2.38% to 2.86% with an additional 6 hours of delay. However, a grade 3b tibial fracture with contamination will have a predicted infection rate increase from 35.6% to 43.3% with 6 hours of further delay. We recommend severe open fractures be debrided emergently while less severe open fractures be debrided urgently