Aims
Patients and Methods
Preclinical data showed poly(methyl methacrylate) (PMMA) loaded with microsilver to be effective against a variety of bacteria. The purpose of this study was to assess patient safety of PMMA spacers with microsilver in prosthetic hip infections in a prospective cohort study. A total of 12 patients with prosthetic hip infections were included for a three-stage revision procedure. All patients received either a gentamicin-PMMA spacer (80 g to 160 g PMMA depending on hip joint dimension) with additional loading of 1% (w/w) of microsilver (0.8 g to 1.6 g per spacer) at surgery 1 followed by a gentamicin-PMMA spacer without microsilver at surgery 2 or vice versa. Implantation of the revision prosthesis was carried out at surgery 3.Objectives
Methods
During the last decades, several research groups have used bisphosphonates for local application to counteract secondary bone resorption after bone grafting, to improve implant fixation or to control bone resorption caused by bone morphogenetic proteins (BMPs). We focused on zoledronate (a bisphosphonate) due to its greater antiresorptive potential over other bisphosphonates. Recently, it has become obvious that the carrier is of importance to modulate the concentration and elution profile of the zoledronic acid locally. Incorporating one fifth of the recommended systemic dose of zoledronate with different apatite matrices and types of bone defects has been shown to enhance bone regeneration significantly
Platelet-rich fibrin matrix (PRFM) has been proved to enhance tenocyte proliferation but has mixed results when used during rotator cuff repair. The optimal PRFM preparation protocol should be determined before clinical application. To screen the best PRFM to each individual’s tenocytes effectively, small-diameter culture wells should be used to increase variables. The gelling effect of PRFM will occur when small-diameter culture wells are used. A co-culture device should be designed to avoid this effect. Tenocytes harvested during rotator cuff repair and blood from a healthy volunteer were used. Tenocytes were seeded in 96-, 24-, 12-, and six-well plates and co-culture devices. Appropriate volumes of PRFM, according to the surface area of each culture well, were treated with tenocytes for seven days. The co-culture device was designed to avoid the gelling effect that occurred in the small-diameter culture well. Cell proliferation was analyzed by water soluble tetrazolium-1 (WST-1) bioassay.Objectives
Methods
Unicompartmental knee arthroplasty (UKA) is one surgical option for treating symptomatic medial osteoarthritis. Clinical studies have shown the functional benefits of UKA; however, the optimal alignment of the tibial component is still debated. The purpose of this study was to evaluate the effects of tibial coronal and sagittal plane alignment in UKA on knee kinematics and cruciate ligament tension, using a musculoskeletal computer simulation. The tibial component was first aligned perpendicular to the mechanical axis of the tibia, with a 7° posterior slope (basic model). Subsequently, coronal and sagittal plane alignments were changed in a simulation programme. Kinematics and cruciate ligament tensions were simulated during weight-bearing deep knee bend and gait motions. Translation was defined as the distance between the most medial and the most lateral femoral positions throughout the cycle.Objectives
Methods
Platelet-rich plasma (PRP) is being used increasingly often in the clinical setting to treat tendon-related pathologies. Yet the optimal PRP preparations to promote tendon healing in different patient populations are poorly defined. Here, we sought to determine whether increasing the concentration of platelet-derived proteins within a derivative of PRP, platelet lysate (PL), enhances tenocyte proliferation and migration Concentrated PLs from both young (< 50 years) and aged (> 50 years) donors were prepared by exposing pooled PRP to a series of freeze-thaw cycles followed by dilution in plasma, and the levels of several platelet-derived proteins were measured using multiplex immunoassay technology. Human tenocytes were cultured with PLs to simulate a clinically relevant PRP treatment range, and cell growth and migration were assessed using DNA quantitation and gap closure assays, respectively.Objectives
Methods
The aim of this study was to examine the efficacy and safety
of multiple boluses of intravenous (IV) tranexamic acid (TXA) on
the hidden blood loss (HBL) and inflammatory response following
primary total hip arthroplasty (THA). A total of 150 patients were allocated randomly to receive a
single bolus of 20 mg/kg IV TXA before the incision (group A), a
single bolus followed by a second bolus of 1 g IV-TXA three hours
later (group B) or a single bolus followed by two boluses of 1 g
IV-TXA three and six hours later (group C). All patients were treated
using a standard peri-operative enhanced recovery protocol. Primary
outcomes were HBL and the level of haemoglobin (Hb) as well as the
levels of C-reactive protein (CRP) and interleukin-6 (IL-6) as markers
of inflammation. Secondary outcomes included the length of stay
in hospital and the incidence of venous thromboembolism (VTE).Aims
Patients and Methods
The objective of this study was to quantify the relative movement between the articular surfaces in the tibiotalar and subtalar joints during normal walking in asymptomatic individuals. 3D movement data of the ankle joint complex were acquired from 18 subjects using a biplanar fluoroscopic system and 3D-to-2D registration of bone models obtained from CT images. Surface relative velocity vectors (SRVVs) of the articular surfaces of the tibiotalar and subtalar joints were calculated. The relative movement of the articulating surfaces was quantified as the mean relative speed (RS) and synchronization index (SIENT) of the SRVVs.Objectives
Methods
The classical longitudinal incision used for the direct anterior
approach (DAA) to the hip does not follow the tension lines of the
skin and can lead to impaired wound healing and poor cosmesis. The
purpose of this retrospective study was to determine the satisfaction
with the scar, and functional and radiographic outcomes comparing
the classic longitudinal incision with a modified skin crease ‘bikini’
when the DAA is used for total hip arthroplasty (THA). A total of 964 patients (51% female; 59% longitudinal, 41% ‘bikini’)
completed a follow-up questionnaire between two and four years postoperatively,
including the Oxford Hip Score (OHS), the University of North Carolina
‘4P’ scar scale (UNC4P) and two items for assessing the aesthetic
appearance of the scar and symptoms of numbness. The positioning
of the components, rates of heterotopic ossification (HO) and rates
of revision were assessed.Aims
Patients and Methods
Thermal stability is a key property in determining the suitability of an antibiotic agent for local application in the treatment of orthopaedic infections. Despite the fact that long-term therapy is a stated goal of novel local delivery carriers, data describing thermal stability over a long period are scarce, and studies that avoid interference from specific carrier materials are absent from the orthopaedic literature. In this study, a total of 38 frequently used antibiotic agents were maintained at 37°C in saline solution, and degradation and antibacterial activity assessed over six weeks. The impact of an initial supplementary heat exposure mimicking exothermically curing bone cement was also tested as this material is commonly used as a local delivery vehicle. Antibiotic degradation was assessed by liquid chromatography coupled to mass spectrometry, or by immunoassays, as appropriate. Antibacterial activity over time was determined by the Kirby-Bauer disk diffusion assay.Objectives
Methods
After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP). Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing.Objectives
Methods
Large bone defects remain a tremendous clinical challenge. There is growing evidence in support of treatment strategies that direct defect repair through an endochondral route, involving a cartilage intermediate. While culture-expanded stem/progenitor cells are being evaluated for this purpose, these cells would compete with endogenous repair cells for limited oxygen and nutrients within ischaemic defects. Alternatively, it may be possible to employ extracellular vesicles (EVs) secreted by culture-expanded cells for overcoming key bottlenecks to endochondral repair, such as defect vascularization, chondrogenesis, and osseous remodelling. While mesenchymal stromal/stem cells are a promising source of therapeutic EVs, other donor cells should also be considered. The efficacy of an EV-based therapeutic will likely depend on the design of companion scaffolds for controlled delivery to specific target cells. Ultimately, the knowledge gained from studies of EVs could one day inform the long-term development of synthetic, engineered nanovesicles. In the meantime, EVs harnessed from
High-intensity narrow-spectrum (HINS) light is
a novel violet-blue light inactivation technology which kills bacteria through
a photodynamic process, and has been shown to have bactericidal
activity against a wide range of species. Specimens from patients
with infected hip and knee arthroplasties were collected over a
one-year period (1 May 2009 to 30 April 2010). A range of these
microbial isolates were tested for sensitivity to HINS-light. During
testing, suspensions of the pathogens were exposed to increasing
doses of HINS-light (of 123mW/cm2 irradiance). Non-light exposed
control samples were also used. The samples were then plated onto
agar plates and incubated at 37°C for 24 hours before enumeration.
Complete inactivation (greater than 4-log10 reduction)
was achieved for all of the isolates. The typical inactivation curve
showed a slow initial reaction followed by a rapid period of inactivation.
The doses of HINS-light required ranged between 118 and 2214 J/cm2.
Gram-positive bacteria were generally found to be more susceptible
than Gram-negative. As HINS-light uses visible wavelengths, it can be safely used
in the presence of patients and staff. This unique feature could
lead to its possible use in the prevention of infection during surgery
and post-operative dressing changes. Cite this article:
Adipose-derived mesenchymal stem cells (ADMSCs) are a promising strategy for orthopaedic applications, particularly in bone repair. Human ADMSCs were cultured in medium supplemented with HPL, Hplasma and a combination of HPL and Hplasma (HPL+Hplasma). Characteristics of these ADMSCs, including osteogenesis, were evaluated in comparison with those cultured in fetal bovine serum (FBS).Objectives
Methods
Vancomycin is commonly added to acrylic bone cement during revision
arthroplasty surgery. Proprietary cement preparations containing
vancomycin are available, but are significantly more expensive.
We investigated whether the elution of antibiotic from ‘home-made’
cement containing vancomycin was comparable with more expensive
commercially available vancomycin impregnated cement. A total of 18 cement discs containing either proprietary CopalG+V;
or ‘home-made’ CopalR+G with vancomycin added by hand, were made.
Each disc contained the same amount of antibiotic (0.5 g gentamycin,
2 g vancomycin) and was immersed in ammonium acetate buffer in a
sealed container. Fluid from each container was sampled at eight
time points over a two-week period. The concentrations of gentamicin
and vancomycin in the fluid were analysed using high performance
liquid chromatography mass spectrometry.Aims
Materials and Methods
The success of long-term transcutaneous implants
depends on dermal attachment to prevent downgrowth of the epithelium
and infection. Hydroxyapatite (HA) coatings and fibronectin (Fn)
have independently been shown to regulate fibroblast activity and
improve attachment. In an attempt to enhance this phenomenon we
adsorbed Fn onto HA-coated substrates. Our study was designed to
test the hypothesis that adsorption of Fn onto HA produces a surface
that will increase the attachment of dermal fibroblasts better than
HA alone or titanium alloy controls. Iodinated Fn was used to investigate the durability of the protein
coating and a bioassay using human dermal fibroblasts was performed
to assess the effects of the coating on cell attachment. Cell attachment
data were compared with those for HA alone and titanium alloy controls
at one, four and 24 hours. Protein attachment peaked within one
hour of incubation and the maximum binding efficiency was achieved
with an initial droplet of 1000 ng. We showed that after 24 hours
one-fifth of the initial Fn coating remained on the substrates,
and this resulted in a significant, three-, four-, and sevenfold
increase in dermal fibroblast attachment strength compared to uncoated controls
at one, four and 24 hours, respectively.
Sustained intra-articular delivery of pharmacological agents is an attractive modality but requires use of a safe carrier that would not induce cartilage damage or fibrosis. Collagen scaffolds are widely available and could be used intra-articularly, but no investigation has looked at the safety of collagen scaffolds within synovial joints. The aim of this study was to determine the safety of collagen scaffold implantation in a validated A total of 96 rabbits were randomly and equally assigned to four different groups: arthrotomy alone; arthrotomy and collagen scaffold placement; contracture surgery; and contracture surgery and collagen scaffold placement. Animals were killed in equal numbers at 72 hours, two weeks, eight weeks, and 24 weeks. Joint contracture was measured, and cartilage and synovial samples underwent histological analysis.Objectives
Materials and Methods
