Duchenne muscular dystrophy (DMD) is a prevalent childhood neuromuscular disease characterized by progressive skeletal and cardiac muscle degeneration due to dystrophin protein deficiency. Despite ongoing drug development efforts, no cure exists, with limited success in preclinical studies. To expedite DMD drug development, we introduce an innovative organ-on-a-chip (OOC) platform. This microfluidic device sustains up to six 3D patient-derived skeletal muscle tissues, enabling real-time evaluation of anti-DMD treatments. Our in vitro model recreates myotube integrity loss, a hallmark of DMD, by encapsulating myogenic precursors in a fibrin-composite matrix using a PDMS casting mold. Continuous contractile regimes mimic sarcolemmal instability, monitored through tissue contractibility and Creatine Kinase (CK) levels—an established marker of muscle damage. We further enhance our platform with a nanoplasmonic CK biosensor, enabling rapid, label-free, and real-time sarcolemmal damage assessment. Combining these elements, our work demonstrates the potential of OOCs in accelerating drug development for DMD and similar neuromuscular disorders.

The surface of any implant device plays an important role in their biocompatibility. After implantation, the physico-chemical surface properties of any biomaterial determine its good/bad response against protein adsorption, cell attachment and proliferation and bacterial adhesion [1]. In this sense, the knowledge of hydrophobicity and surface tension of any new-developed biomaterial is an added value for the final product. Polymeric implants, among which are poly-D-Lactic acid (PLDA), are well characterized biodegradable biomaterials that have been proposed as an alternative to metallic implants for fracture fixation. However, their use in the clinical practice has been limited due to insufficient osseointegration and adverse tissue reactions. Recently it has been demonstrated the feasibility of introducing Mg particles within the PLDA matrix as a new strategy to improve the bioactivity and mechanical properties of PLDA whereas simultaneously modulating the degradation rate of Mg [2]. In this work, the surface of new amorphous and crystalline composites of PLDA with two different Mg concentrations are characterized in terms of hydrophobicity and surface tension.

Amorphous and crystalline PLDA from Natureworks were reinforced with Mg particles through a processing route that contained four different stages: drying, hot extrusion, grinding and compression moulding. Two different Mg concentration were used: 1 wt.% and 10 wt.% Hydrophobicity was obtained by goniometry using water as probe liquid (θ_W). The surface tension was determined through the Young Equation using water, formamide and diiodomethane as probe liquids. Van Oss approach was used to split the surface tension into the Lifshitz-van der Waals component (γ^LW) and acid-base component (γ^AB). The acid-base was also divided into the electron-donor (γ⁻) and electron-acceptor parameters (γ⁺).

The water contact angle was similar in amorphous and crystalline samples. Mg always reduced the θ_W value, no matter the Mg concentration used. Reductions were similar for both Mg concentrations. The surface tension in amorphous samples was comprised between 26 and 36 mJ/m² and in crystalline samples was between 30 and 36 mJ/m². Although values were very similar, the deviations observed for crystalline samples were always smaller than for amorphous. An important effect of Mg in the composites was the increase in the parameter γ-.

Mg addition makes the polymer less hydrophobic. The increase of γ⁻ may be related to an increase in the negative surface charge of Mg samples. The hydrophobic reduction plus the more negative surface could impair the bacterial approach and further adhesion to the surface of the new composites, which implies an advance in the fight against infections.

Introduction: The most important cause of prosthetic joint infection (PJI) is the contamination of the wound during the surgery. Nowadays, it doesn’t exist any image or laboratory test for early detection of prosthesis with a higher risk of developing a PJI.

Aim: The primary aim was to evaluate the usefulness of different intraoperative samples during the surgery of implantation of a primary hip arthroplasty (PHA) as a predicting factor of PJI.

Methods: A prospective cohort study was performed. All patients (n= 278) who underwent a PHA from January ’06 to November ’08 were included. Three samples: a piece of articular capsule (TS), a swab (S) and synovial fluid (SF) inoculated into blood flask were taken in each patient during the first 45 minutes of surgery. Other possible risk factors of PJI like age, sex, ASA, comorbidity and surgical time were registered.

Results: A total of 278 patients were included. 30 cultures (8 SF, 13 TS and 9 S) were positive in 29 patients. The most frequent microorganism isolated was Coagulase-negative staphylococci (CNS) (66.6%). The rate of PJI (early and late) in the subgroup of patients with positive intraoperative cultures for CNS was 25% while in the subgroup with all negative cultures was 5.2% (RR=4.8; p=0.007). Other factors significantly associated with a higher rate of PJI in the univariate analysis were: ASA III (RR=9.12; p=0.02), cardiopathy (RR= 2.82; p=0.04), obstructive pulmonary chronic disease (RR=5; p=0.02) and rheumatoid arthritis (RR=4.16; p=0.04). Multivariate analysis found ASA III (Odds ratio 10.9; CI 95% 1.27–94.6; p=0.02) and a positive intraoperative culture for CNS (Odds ratio 5.92; CI 95%=1.8–19.85; p=0.03) as independent risk factors for PJI.

Conclusion: Positive intraoperative culture for CNS during PHA was independently associated with the development of PJI.

Purpose: To review the results of periprosthetic femoral fractures treated using cortical strut allograft and plate internal fixation.

Material & Methods: Between November 1996 and July 2006, 17 patients with periprosthetic fractures of the femur after hip arthroplasty were treated using deep-frozen cortical strut allografts as an adjunct support after internal fixation. The average age was 79 years (range 56 to 96 years) with 13 woman and 4 men. According to the Vancouver classification system, there were 6 type B1, 5 type B2, 1 type B3 and 5 type C fractures. All fractures were closed except for one type I of Gustilo. Twelve patients had internal fixation of the fracture using a Dall-Miles cable and plate system, 5 using a AO/ASIF 4.5 dynamic compression plate, and 2 had an associated revision arthroplasty of the stem. Cortical strut allograft was used from the femur in 6 cases and from the tibia in 11 cases. Mean follow-up was of 97.5 weeks.

Results: One patient presented a rupture of a screw and varus displacement of the fracture, but healed without symptomatic complaints. A superficial infection occurred in the patient with open fracture. All the patients, except for two, required allogenic blood transfusion. Mean inhospital stay was of 18.6 days and walk with weigh was allowed at a mean of 50.9 days. Two patients died few weeks after the treatment due to complications of their previous pathological disorders. Aseptic loosening of a hip arthroplasty occurred at two years follow-up requiring revision surgery. Three patients referred mild pain at the last follow-up visit.

Conclusions: Cortical strut allograft associated with internal fixation has provided satisfactory results in the present serie. We consider this procedure safe and effective, specially for type B1 and C periprosthetic femoral fractures.

Introduction and purpose: There still remain controversies with regard to knee replacements, such as the preservation or replacement of the patellar surface. Although numerous studies have compared the clinical results of the two procedures, there have been few long-term radiological follow-up studies of the non-resurfaced patella. Our purpose is to assess this follow-up and determine the relation to clinical pain pictures of patellar origin.

Materials and methods: We carried out a clinical and radiological study of 74 PFC modular arthroplasties without patellar resurfacing with a mean follow-up of 10 years (range: 9–12 years). We measured the size and height of the patella, Wiberg classification, degree of patellar sclerosis, patellar excursion and presence and size of bone spurs. We carried out an exhaustive examination of the extensor apparatus. We related the radiological data to the clinical picture of the patella.

Results: We observed a tendency toward reduced titlting, increased height and width and diminished patellar thickness. None of these variations was statistically related to the onset of patellar pain or sustained pain.

Conclusions: Radiological variations of the non-resurfaced patella in total knee arthroplasty do not result in patellar clinical pictures.

Purpose: We assess the advantages of helical computerised tomography as compared to conventional radiological methods in the diagnosis of this problem in the acetabulum.

Materials and methods: We studied 51 patients with 63 porous hemispheric acetabular implants coated with hydroxyapatite who were part of a planned radiological follow-up. After 10 years they were examined with helical computerised tomography according to a protocol designed to minimise metal artefacts. We compared the diagnosis of acetabular osteolysis by the two imaging techniques, taking the presence of delimited areas of absent trabeculation as a criterion.

Results: With computerised tomography we detected 23 osteolytic lesions in 19 hips, of which 5 had been diagnosed by conventional radiology. Only 3 patients presented symptoms in the form of mild-moderate pain. The mean volume of the lesions was 1.61 cc (SD: 1.41) with a minimum of 0.3 and maximum of 5.5 cc.

Conclusions: Computerised tomography can be a useful tool in the diagnosis and follow-up of acetabular osteolysis in total hip replacement. More studies are needed to complete its diagnostic possibilities and specify its indications.

Introduction and Objectives: This rare disease (17 per million newborns) was described by Chatelaine in 1882 and is more prevalent in females compared to males (2.3:1). It is commonly accompanied by congenital or genetic malformations. Within the syndrome known as genu recurvatum, congenital knee dislocation (CKD) is the most extreme clinical form. In view of the scarcity of trials and reviews on the subject of CKD and results of therapy for the same, we determined to gather clinical case data from the hospital from 01–01-1964 to 01–01-2003 and evaluate therapeutic, orthopaedic, and surgical experience.

Materials and Methods: Of 28,753 patients treated in the aforementioned period, 55 were treated for genu recurvatum. We selected 22 with unilateral or bilateral CKD. We individualised the cases of 14 patients with 20 knees as patients diagnosed and treated since birth by this centre, excluding those with multi-malformation genetic syndromes (Larsen’s syndrome, arthrogryposis, etc.). In terms of treatment, 13 knees were treated orthopaedically by means of successive manipulations and splinting until 90° of flexion was achieved. At that point, physical therapy was initiated. There were 7 other knees that received at least one surgical treatment when results of the previously-described orthopaedic procedures were unsatisfactory. The clinical outcome for the treatment method used in each case was assessed by means of evaluation of range of mobility of the knee joint, stability upon examination, residual deviation from the axes, and ability of the patient to walk at time of release.

Results: Of the 65% of knees that were treated exclusively by orthopaedic methods, we observed ranges of flexion and stability such that splinting was not needed at an average of 55.2 days, with good to excellent clinical outcomes at an average of 42.4 days. Of the 35% of knees that required at least one surgical procedure, the procedure was performed between the ages of 30 and 176 days of life, with a mean of 90.8 days. As many as 75% of these knees required repeated surgical intervention during the treatment period, and good to excellent results were achieved in only 35% by 5 years of age.

Discussion and Conclusions: Orthopaedic treatment continues to be the foundation of managing these patients, and plays a vital role even in cases were surgical intervention is chosen. The existence of other genetic or non-genetic developmental anomalies concurrent with CKD will determine the therapeutic strategy that is indicated and when such action should take place. We do not recommend surgical treatment except in cases of a continued lack of response to orthopaedic treatment.

Introduction: Traumatic injury to a peripheral nerve with loss of continuity is a disabling condition due to denervation. Traditional treatment consists of nerve grafting with the consequence of unwanted side effects at the donor site (sural nerve).

Aims: To present an alternative treatment using two different biomaterials as implants bridging both ends of nerve.

Materials and Methods: The same hand surgeon treated twenty-one patients with traumatic laceration of less than 3 cm in the upper limb. Two different kind of flexible tubular sheaths were implanted: 18 patients with one and 3 with other. An independent observer assessed McKenney’s and two points discrimination tests for functional out come. We describe the surgical technique and report the full data.

Discussion: Polyglicolic acid is designed to create a conduct for axonal growth across a nerve gap making it unnecessary to carry out a nerve grafting. Its use is feasible in clean wounds less than 3 cm in length. It is technically easy to implant and reabsorbed within 3 months.

Conclusions: The satisfactory results in terms of functional recovery suggest the convenience of this technique to shorten the operating time and avoid donor site side effects.