This article presents examination of a failed total hip replacement with surface engineered metal-on-metal (MoM) articulation. The implant was coated with a thin TiNbN film (Physical Vapor Deposition), and at retrieval 53 months after implantation the coating was abraded on weight-bearing part of the head and acetabular component. Scanning electron microscopy of bearing surfaces demonstrated multifocal crack formation, delamination of small film fragments, and formation of aggregates containing nanometer sized wear debris. We also observed coating damage in third body mechanism. Complex failure mechanism of TiNbN coating demonstrated in this study suggests insufficient bonding strength between the coating and substrate alloy and raise concerns regarding the use of such coatings in total hip arthroplasty with MoM bearing. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1043-1049, 2016.

Background Polymorphonuclear neutrophils (PMN)are the first cells to take part in the local foreign body reaction in aseptic loosening of endoprostheses. The aim of this study was to evaluate the systemic host reaction to total joint replacement by measuring the production of nitric oxide by neutrophils before and after total joint replacement.Patients and method Blood samples were collected from 33 patients (27 hips and 6 knees) before surgery, and 2 weeks, 2 months and 2.5-3 years after surgery. The levels of nitric oxide produced by PMN were measured by the method described by Markert et al. (1994).Results Patients reporting pain in the region of the implant 3 years after surgery, and also patients with radiographic signs of loosening, had higher production of NO in the early period and 3 years after the implantation than those with good clinical results.Interpretation We propose that elevated levels of nitric oxide production by PMNs may serve as a marker of total joint prosthesis loosening.

This study presents the development and remodelling of 78 dysplastic hips treated conservatively. The hip joints were observed from the end of conservative treatment, during growth until maturity, up to the age of 18 years and beyond. We used 9 radiological parameters of hip structure. The parameters described the status of the acetabulum, proximal end of the femur and the joint congruity. The values of these parameters were compared with the norms established for healthy hips. The material was divided into groups with regard to the parameter values. It was found that hip congruity at the age from 2 to 5 years or from 2 to 7 years is the most important factor that determines the development of both the acetabulum and the whole joint. Based on the values of three radiological parameters, describing hip congruity at this period of life, it was found that the remodelling of a dysplastic hip follows one of three definable models. If we attribute the development of a given hip to a given model, then the status of this hip at maturity is predictable. What makes the prediction of the final condition of the hip feasible is the observation of the hip remodelling process from age 2 to 5 or 7 years. This also permits a decision regarding surgery to eliminate any dysplastic elements from the hip during the childs optimal age for operative treatment. (Hip International 2002; 12: 320-33).

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Kli ni ka Or to pe dii Ogól nej, On ko lo gicz nej i Trau ma to lo gii, Uni wer sy tet Me dycz ny w Po zna niu, Polska Department of General Orthopedics, Musculoskeletal Oncology and Trauma Surgery, Poznań University of Medical Sciences, Poland STRESZCZENIEWstęp. Trzpień Zweymüllera jest dobrze znany i powszechnie stosowany w Europie od 1980 r. Nieliczni auto rzy wska zu ją na wy stę po wa nie za gęsz czeń ko ści gąb cza stej pod trzpie niem, na to miast do tąd nie opi sa no me cha ni zmu sto ją ce go u pod staw te go pro ce su. Ce lem pra cy by ło zna le zie nie czyn ni ków wpły wa ją cych na taką prze bu do wę ko ści wo kół trzpie nia Zweymülle ra.Ma te riał i me to dy. Do ba da nia włą czo no 102 ko lej nych pa cjen tów (69 ko biet i 33 mę żczyzn), u któ rych za im plan to wa no trzpień Zweymülle ra dru giej ge ne ra cji. Śred nia okre su ob ser wa cji wy nio sła 9,2 la ta (od 6-15 lat). In deks ko rów ko wy (IK) zo stał wy zna cza ny ja ko ilo raz sze ro ko ści trzpie nia en do pro te zy oraz sze ro ko ści trzo nu ko ści udo wej w 3 i 5 stre fie Gru ena.Wy ni ki. U pa cjen tów z sze ro kim ka na łem ko ści udo wej i cien ki mi war stwa mi ko ro wy mi (IK ≥0.4) wy kaza no do dat nią ko re la cję z obec no ścią za gęsz czeń ko ści pod trzpie niem (ZKpT) (p<0.0001, r=0.6028). Śred nia in dek su ko rów ko we go w okre sie ob ser wa cji zmniej szy ła się o 0,02, na to miast śred nia gru bość ko ści ko ro wej w 3 i 5 stre fie Gru ena wzro sła o 2 mi li me try. Po gru bie nie ko ści ko ro wej by ło więk sze u pa cjen tów bez ZKpT (1,5 a 2,4 mm, p=0.0172).Wnioski. 1. Obec ność cien kich ko ści ko ro wych wraz z sze ro kim ka na łem ko ści udo wej (IK ≥0.4) mo że skut ko wać wy stą pie niem za gęsz czeń ko ści pod trzpie niem. 2. ZKpT po ja wia ją się praw do po dob nie w wy ni ku prze no sze nia ob cią żeń me cha nicz nych przez trzpień na kość w 4 stre fie Gru ena. 3. Ich obec ność nie de ter minu je zwięk szo nej czę sto ści asep tycz ne go ob lu zo wa nia ani nie sta bil no ści trzpie nia.Słowa kluczowe: endoprotezoplastyka stawu biodrowego, zagęszczenia kości, trzpień Zweymüllera, indeks korówkowy SUMMARY Background. The Zweymüller stem is well-known in Europe and widely used for total hip replacement since 1980. Few authors have noted the presence of increased bone density below the tip of the stem; however, the underlying mechanism is still unknown. The aim of this study was to reveal factors influencing bone remodeling around the tip of the Zweymüller stem.Material and methods. 102 consecutive patients (69 women and 33 men) who received a second generation Zweymüller type stem (123 prostheses) were included. Mean follow-up was 9.2 years (6 -15 years). A Cortical Index (CI) was defined as the ratio between stem width and external cortical diameter in Gruen zones 3 and 5.Results. Patients with a wide femoral canal and thin cortical bone (CI ≥0.4) demonstrated a positive corre lation with the presence of increased bone density (IBD) below the stem (p<0.0001, r=0.6028). During follow-up, the mean Cortical Index d...