Bacteria Living in Biofilms in Fluids: Could Chemical Antibiofilm Pretreatment of Culture Represent a Paradigm Shift in Diagnostics?

Biofilms are multicellular aggregates of bacteria immersed in an extracellular matrix that forms on various surfaces, including biological tissues and artificial surfaces. However, more and more reports point out the fact that even biological fluids and semifluid, such as synovial liquid, blood, urine, or mucus and feces, harbor "non-attached" biofilm aggregates of bacteria, which represent a significant phenomenon with critical clinical implications that remain to be fully investigated. In particular, biofilm aggregates in biological fluid samples have been shown to play a relevant role in bacterial count and in the overall accuracy of microbiological diagnosis. In line with these observations, the introduction in the clinical setting of fluid sample pretreatment with an antibiofilm chemical compound called dithiothreitol (DTT), which is able to dislodge microorganisms from their intercellular matrix without killing them, would effectively improve the microbiological yield and increase the sensitivity of cultural examination, compared to the current microbiological techniques. While other ongoing research continues to unveil the complexity of biofilm formation in biological fluids and its impact on infection pathogenesis and diagnosis, we here hypothesize that the routine use of a chemical antibiofilm pretreatment of fluid and semi-solid samples may lead to a paradigm shift in the microbiological approach to the diagnosis of biofilm-related infections and should be further investigated and eventually implemented in the clinical setting.

Dithiotreitol pre-treatment of synovial fluid samples improves microbiological counts in peri-prosthetic joint infection.

PURPOSE: Synovial fluid cultures of periprosthetic joint infections (PJI) may be limited by bacteria living in the fluids as biofilm-aggregates. The antibiofilm pre-treatment of synovial fluids with dithiotreitol (DTT) could improve bacterial counts and microbiological early stage diagnosis in patients with suspected PJI. METHODS: Synovial fluids collected from 57 subjects, affected by painful total hip or knee replacement, were divided into two aliquots, one pre-treated with DTT and one with normal saline. All samples were plated for microbial counts. Sensitivity of cultural examination and bacterial counts of pre-treated and control samples were then calculated and statistically compared. RESULTS: Dithiothreitol pre-treatment led to a higher number of positive samples, compared to controls (27 vs 19), leading to a statistically significant increase in the sensitivity of the microbiological count examination from 54.3 to 77.1% and in colony-forming units count from 1884 ± 2.129 CFU/mL with saline pre-treatment to 20.442 ± 19.270 with DTT pre-treatment (P = 0.02). CONCLUSIONS: To our knowledge, this is the first report showing the ability of a chemical antibiofilm pre-treatment to increase the sensitivity of microbiological examination in the synovial fluid of patients with peri-prosthetic joint infection. If confirmed by larger studies, this finding may have a significant impact on routine microbiological procedures applied to synovial fluids and brings further support to the key role of bacteria living in biofilm-formed aggregates in joint infections.

The Role of Platelet-Rich Plasma on the Chondrogenic and Osteogenic Differentiation of Human Amniotic-Fluid-Derived Stem Cells.

Amniotic fluid represents a new and promising source of engraftable stem cells. The purpose of this study was to investigate the in vitro effects of platelet-rich plasma (PRP) on amniotic-fluid-derived stem cells (AFSCs) on chondrogenic or osteogenic differentiation potential. Amniotic fluid samples were obtained from women undergoing amniocentesis for prenatal diagnosis at 16-18 weeks of pregnancy. Undifferentiated human AFSCs were cocultured with PRP for 14 days. The study includes two protocols investigating the effects of activated PRP using two different methods: via freeze-thaw cycles and via the addition of calcium gluconate. On the 14th day of culturing, the differentiation potential of the cocultured AFSCs was then compared with undifferentiated AFSCs. Staining with alcian blue solution (ABS) and alizarine red solution (ARS) was performed, and chondrogenic- and osteogenic-associated genes markers were investigated. ABS demonstrated enhanced glycosaminoglycan expression. Cocultured cells expressed chondrocyte-associated genes, determined by real-time polymerase chain reaction (RT-PCR), including type I collagen, type II collagen, COMP, and aggrecan. In regard to the osteogenic markers, osteopontin and bone sialoprotein, there were no changes. In particular, the activation of PRP using the freeze-thaw cycle protocol showed a higher expression of the chondrogenic markers. Our preliminary in vitro results showed that PRP has good potential in the chondrogenic differentiation of AFSCs.

Pisiform Bone Dislocation in a Pediatric Patient: What is the Best Treatment? Case Report and Review of the Literature.

Traumatic dislocation of the pisiform bone (PB) is a rare injury of the carpal bones, especially in pediatric patients. A few cases were reported, and there is no consensus about the treatment. Each author supports his own method, such as an open reduction internal fixation (ORIF) approach or a closed reduction. However, failures of both techniques with recurrent dislocation of the PB have been reported in the literature. In this article, a fracture dislocation of the PB was treated with ORIF in an 11-year-old boy with a greenstick radial fracture. In addition, a review of the literature about pisiform fracture dislocation in children has been made.

Painful total knee arthroplasty: Infrapatellar branch of the saphenous nerve selective denervation. A case series.

INTRODUCTION: Total knee arthroplasty (TKA) is a reliable and widespread solution for knee osteoarthritis treatment, but about 20% of the patients complains of persisting pain. Neuroma formation in the IPBSN (infrapatellar branch of the saphenous nerve) is an undervalued cause of persistent anterior pain after TKA. The aim of this study was to evaluate the effectiveness of the selective neuroma denervation on patients satisfaction and pain improvement. MATHERIAL AND METHODS: Between 2014 and 2020, we evaluated 13 patients suffering from persistent anterior knee pain and numbness after TKA who underwent a surgical neurectomy of the IPBSN. After clinical assessment and diagnosis confirmation, we carried out the surgery. Short Form 12 Health (SF12), Oxford Knee Score (OKS), and Numeric Rating Scale (NRS) have been collected before and after the procedure. After the surgical treatment, the symptom's resolution and patients' satisfaction were attested by the achievement of the Minimal ClinicallyImportantDifference(MCID) of the self-administered patient-reported outcome measures (PROMs). RESULTS: Our results showed a statistically significant improvement (p < 0.05) of patients pain perception (mean NRS improvement -4.2, SD 2.5) and overall satisfaction (with a mean increase in OKS of 14.5 points SD 9.4, and in SF12 of 6.5 points SD 4.0). CONCLUSIONS: Hence, our study suggests that selective neuroma denervation may be an effective solution to improve the quality of life of patients who develop this complication after TKA.

A novel biplanar medial opening-wedge high tibial osteotomy: the Z-shaped technique. A case series at 7.2 years follow-up.

BACKGROUND: High tibial osteotomy (HTO) provides reliable and good long-term results, if performed with correct indications, but different techniques and types of fixation have been described. The purpose of this study is to present a novel modified biplanar medial opening-wedge (MOW) HTO technique where the osteotomies are performed in a Z-shaped fashion, and to present the medium-term clinical and radiographic results. MATERIALS AND METHODS: We present a case series of 75 patients (80 knees) with mean age of 45.8 years, affected by isolated medial knee osteoarthritis and symptomatic varus knee malalignment, who underwent novel biplanar Z-shaped MOWHTO. Clinical and radiological outcomes were collected, retrospectively before surgery and at median follow-up of 7.2 years (95% CI 5.6-9.2 months) after surgery. Clinical results and satisfaction were assessed by visual analog scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and Likert scale. Radiological assessment involved the evaluation of the medial proximal tibial angle (MPTA), tibial slope (TS), Caton-Deschamps index, and knee osteoarthritis grade according to Ahlbäck classification. Pre- and postoperative results were compared using the two-tailed t-test or Wilcoxon's test of independent samples for paired data or nonparametric analog. P < 0.05 was considered significant. RESULTS: At medium-term follow-up, Z-shaped MOWHTO showed a survival rate of 95 ± 1.7% with failure occurring in four knees due to symptom recurrence and osteoarthritis progression. No perioperative complications were observed (intraarticular fracture, delayed union or nonunion, and neurological injury). Mean bone healing time was 12 weeks. Clinical scores showed significant improvement at last follow-up and a good grade of satisfaction. MPTA increased significantly, while Caton-Deschamps index decreased significantly. No significant TS increase was found. CONCLUSIONS: Modified biplanar Z-shaped MOWHTO is a safe and reliable technique that offers satisfactory clinical and radiological medium-term outcomes with low knee arthroplasty conversion rate. The unique three-dimensional geometrical conformation potentially provides a favorable environment for bone healing, increased anteroposterior and rotational stability, and safer opening-wedge loading force application with low lateral hinge fracture risk. LEVEL OF EVIDENCE: Level IV, retrospective observational case series study. Trial registration The study protocol was approved by the Internal Review Board of our Institution (authorization number 54/2019, 20 November 2019).