Evaluation of microbial adhesion and biofilm formation on nano-structured and nano-coated ortho-prosthetic materials by a dynamic model

The bio-engineering technologies of medical devices through nano-structuring and coating was recently proposed to improve biocompatibility and to reduce microbial adhesion in the prevention of implantable device-related infections. Our aim was to evaluate the ability of new nano-structured and coated materials to prevent the adhesion and biofilm formation, according to the American Standard Test Method ASTM-E2647-13. The materials composition was determined by X-ray Fluorescence and Laser Induced Breakdown Spectroscopy. Silver release was evaluated by Inductively Coupled Plasma Mass Spectrometry analysis. The gene expression levels of the Quorum Sensing Las and Rhl system were evaluated by the ΔΔCt method. The Log bacterial density (Log CFU/cm2) on TiAl6V4 was 4.41 ± 0.76 and 4.63 ± 1.01 on TiAl6V4-AgNPs compared to 2.57 ± 0.70 on CoCr and 2.73 ± 0.61 on CoCr-AgNPs (P < 0.0001, A.N.O.V.A.- one way test). The silver release was found to be equal to 17.8 ± 0.2 μg/L after the batch phase and 1.3 ± 0.1 μg/L during continuous flow. The rhlR gene resulted in a 2.70-fold increased expression in biofilm growth on the silver nanoparticles (AgNPs) coating. In conclusion, CoCr showed a greater ability to reduce microbial adhesion, independently of the AgNPs coating. The silver release resulted in promoting the up-regulation of the Rhl system. Further investigation should be conducted to optimize the effectiveness of the coating

Distally based peroneus brevis muscle flap in reconstructive surgery of the lower leg: Postoperative ankle function and stability evaluation

BACKGROUND: Defects of the distal third of the lower leg with exposed tendons or bone require either local or free flap coverage. Several flaps have been developed, and the distally pedicled peroneus brevis muscle flap has been proven to be a valid local flap alternative. PATIENTS AND METHODS: Peroneus brevis muscle is dissected from the lateral surface of the fibula from proximal to distal, but no further than approximately 3-6 cm proximally to the lateral malleolus, where the most distal vascular pedicle from the peroneal artery enters the muscle consistently. This allows the muscle to be transposed to more distal lesions. The muscle is then covered with meshed split-skin graft. Between 2002 and 2008, 10 patients with defects of the lower leg in the distal lower third have been treated using this muscle flap. The defects were located over the Achilles tendon, the medial and lateral malleolar, the anterior region of the ankle and the heel area. Each patient was examined through assigning clinical demerit points according to a modified Weber scale, and through Olerud-Molander ankle score to analyse postoperative ankle stability and functionality after reverse peroneus brevis flap reconstruction of the defect. RESULTS: All flaps survived completely, and no secondary local flap was required. In our experience, no complication or patient discomfort was noted. Donor-site morbidity was acceptable and restricted to the scar in the lateral lower leg. As demonstrated by the two score evaluations, the functions of foot eversion and plantar flexion as well as ankle functionality and stability were maintained due to preservation of peroneus longus muscle. CONCLUSION: The reverse peroneus muscle flap is ideally suited for small-to-moderate defects of the distal third of the lower leg. This flap offers a convincing alternative for covering defects in the distal leg region. Its arc of rotation allows coverage of more anterior defects of the ankle, of defects of the Achilles tendon and of the heel area as well as of lateral and medial malleolus areas. It is simple to raise and is often transposed easily within the wound without further dissection. As long as the peroneus longus is preserved, ankle instability is not expected

Impending atypical femoral fractures associated with bisphosphonates: postoperative diagnosis after hip prosthesis. Clinical cases presentation

Abstract Background and aim: Number of hip prosthesis implants in arthritis, number of patients treated with bisphosphonates to prevent fragility fractures and, together, number of atypical femoral fracture's cases are increasing. Case series: This article describes two cases of hip arthritis, treated with hip replacement, in patients using bisphosphonates for a long time; in both cases an incomplete atypical femoral fracture was misdiagnosed before the surgery. Authors describe the importance to carry out a complete osteometabolic and radiographic pre-operative examination of patients in treatment with bisphosphonates going to hip replacement, to check the possible presence of incomplete atypical femoral fracture and to optimize surgical and pharmacological treatment. Conclusions: In hip prosthesis surgery, prior diagnosis of incomplete atypical femoral fractures can indicate the choice of a different kind of prosthesis stem to optimize surgical results. This can also positively impact to rehabilitation in term of duration and daily activities recovery

Clinical and radiographic short mid-term outcomes of primary total stabilizer knee arthroplasty

A successful Total Knee Arthroplasty (TKA) requires stability, but rarely in primary TKA, a prosthesis with more constraint than a posterior-stabilizer (PS) is necessary. In patients with severe varus/valgus deformities with incompetent collateral ligaments or in knees that cannot be adequately balanced after ligaments release, a total-stabilizer (TS) prosthesis may be required. The purpose of our retrospective study is to evaluate clinical and radiographic outcomes at short mid-term follow-up in patients treated with a TS TKA. Between January 2013 and August 2016, 36 patients (38 knees) were treated with Stryker Triathlon TS cemented implants. Clinical and radiographic evaluation were performed preoperatively and postoperatively at 1 month, 3 months, 6 months, 1 year and at 1-year intervals thereafter. At final follow-up, 33 patients (35 knees) remained and were included in this study and followed with a mean follow-up of 26.6 months. Clinical evaluation was performed using the Western Ontario and McMaster Universities Arthritis Index (WOMAC score) and the Knee Society rating system that is subdivided into a knee score (KS) that rates only the knee joint itself and a functional score (FS). Knee Score (KS) and Functional Score (FS) increased significantly from a mean pre-operative value of 48 and 45, respectively, to a post-operative value at last follow-up of 86 and 82, respectively. Also WOMAC score improved significantly: the mean pre-operative WOMAC score was 45, while the mean post-operative WOMAC score, at last follow-up, was 19. The difference between pre- and post- operative results was significant at statistical analysis. In our opinion, when the adequately prosthesis balancing isn’t possible, because of primary or secondary severe varus/valgus deformity or severe soft tissues retraction, an available option is to perform a total knee arthroplasty with a total stabilizer polyethylene insert. TS prosthesis gives more stability during the most of ROM and, in addition, Triathlon system provides surgeons the possibility to choose a more constrained implant, than a standard PS one, during surgical procedure saving the bone stock. Our experience with this kind of prosthesis has provided good clinical and radiographic outcomes at a short mid-term follow-up with a low-rate of complications