The aim of this study is to print 3D polycaprolactone (PCL) scaffolds at high and low temperature (HT/LT) combined with salt leaching to induced porosity/larger pore size and improve material degradation without compromising cellular activity of printed scaffolds. PCL solutions with sodium chloride (NaCl) particles either directly printed in LT or were casted, dried, and printed in HT followed by washing in deionized water (DI) to leach out the salt. Micro-Computed tomography (Micro-CT) and scanning electron microscope (SEM) were performed for morphological analysis. The effect of the porosity on the mechanical properties and degradation was evaluated by a tensile test and etching with NaOH, respectively. To evaluate cellular responses, human bone marrow-derived mesenchymal stem/stromal cells (hBMSCs) were cultured on the scaffolds and their viability, attachment, morphology, proliferation, and osteogenic differentiation were assessed. Micro-CT and SEM analysis showed that porosity induced by the salt leaching increased with increasing the salt content in HT, however no change was observed in LT. Structure thickness reduced with elevating NaCl content. Mass loss of scaffolds dramatically increased with elevated porosity in HT. Dog bone-shaped specimens with induced porosity exhibited higher ductility and toughness but less strength and stiffness under the tension in HT whereas they showed decrease in all mechanical properties in LT. All scaffolds showed excellent cytocompatibility. Cells were able to attach on the surface of the scaffolds and grow up to 14 days. Microscopy images of the seeded scaffolds showed substantial increase in the formation of extracellular matrix (ECM) network and elongation of the cells. The study demonstrated the ability of combining 3D printing and particulate leaching together to fabricate porous PCL scaffolds. The scaffolds were successfully printed with various salt content without negatively affecting cell responses. Printing porous thermoplastic polymer could be of great importance for temporary biocompatible implants in bone tissue engineering applications.

Mesenchymal stem cells (MSC) have been used for bone regenerative applications as an alternative approach to bone grafting. Selecting the appropriate source of MSC is vital for the success of this therapeutic approach. MSC can be obtained from various tissues, but the most used sources of MSC are Bone marrow (BMSC), followed by adipose tissue (ASC). A donor-matched comparison of these two sources of MSC ensures robust and reliable results.

Despite the similarities in morphology and immunophenotype of donor-matched ASC and BMSC, differences existed in their proliferation and in vitro differentiation potential, particularly osteogenic differentiation that was superior for BMSC, compared to ASC. However, these differences were substantially influenced by donor variations. In vivo, although the upregulated expression of osteogenesis-related genes in both ASC and BMSC, more bone was regenerated in the calvarial defects treated with BMSC compared to ASC, especially during the initial period of healing. According to these findings, compared to ASC, BMSC may result in faster regeneration and healing, when used for bone regenerative applications.

Abstract

Background

The advent of EOS imaging has offered clinicians the opportunity to image the whole skeleton in the anatomical standing position with a smaller radiation dose than standard spine roentgenograms. It is known as the fifth modality of imaging. Current NICE guidelines do not recommend EOS scans over x-rays citing: “The evidence indicated insufficient patient benefit in terms of radiation dose reduction and increased throughput to justify its cost”.

Introduction

Pulmonary Tuberculosis (TB) can be detected by sputum cultures. However, Extra Pulmonary Spinal Tuberculosis (EPSTB), diagnosis is challenging as it relies on retrieving a sample. It is usually discovered in the late stages of presentation due to its slow onset and vague early presentation. Difficulty in detecting Mycobacterium Tuberculosis bacteria from specimens is well documented and therefore often leads to culture negative results. Diagnostic imaging is helpful to initiate empirical therapy, but growing incidence of multidrug resistant TB adds further challenges.

Gel-based autologous chondrocyte implantation (ACI) over the years have shown encouraging results in repairing the articular cartilage. More recently, the use of cultured mesenchymal stem cells (MSC) has represented a promising treatment option with the potential to differentiate and restore the hyaline cartilage in a more efficient way. This study aims to compare the clinical and radiological outcome obtained in these two groups.

Twenty-eight consecutive symptomatic patients diagnosed with full-thickness cartilage defects were assigned to two treatment groups (16 patients cultured bone marrow-derived MSC and 12 patients with gel-type ACI). The MSC group patients underwent microfracture and bone marrow aspiration in the first stage and injection of cultured MSC into the knee in the second stage. Clinical and radiological results were compared at a minimum follow up of five years

There was excellent clinical outcome noted with no statistically significant difference between the two groups. Both ACI and MSC group showed significant improvement of the KOOS, Lysholm and IKDC scores as compared to their preoperative values and this was maintained at 5 years follow up. The average MOCART score for all lesions was also nearly similar in the two groups. The mean T2* relaxation-times for the repair tissue and native cartilage were 27.8 and 30.6 respectively in the ACI group and 28 and 29.6 respectively in the MSC group.

Use of cultured MSC is less invasive, technically simpler and also avoids the need for a second surgery as compared to an ACI technique. With similar encouraging clinical results seen and the proven ability to restore true hyaline cartilage, cultured MSC represent a favorable treatment option in articular cartilage repair.

Background of study

Total Knee Replacement (TKR) is one of the commonest elective arthroplasty operations. Crepe dressings are used following TKR by most surgeons as it may provide comfort and hemostasis through external pressure however, may reduce early range of motion (ROM). Avoiding crepe dressings after TKR saves operating time, avoids bulky dressings (which may reduce ROM) and allows interventions such as cryotherapy in the early post-operative period. There are no published studies comparing the use of crepe dressing after TKR with an impermeable dressing alone

This paper reports on a proof of concept project funded by the UK National Council for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), with the aim of developing an in vitro model to recapitulate the human osteoarthritic joint, based on a multiple human cell type co-culture system, for research and drug development in OA. The targets were: (i) the development of a cell culture platform that could produce a mixed stable cell culture of cell types that represent the key components of the human joint: synoviocytes – type I and type II; osteoblasts; osteoclasts; chondrocytes/cartilage or cartilage-like matrix; adipocytes; and immune cells. (ii) demonstration of cell phenotype stability and viability for at least 72 hours. In order to establish the cell culture platform we have developed an eight-channel cell printer, capable of accurately and reliably printing the required cell types to create osteochondral and synovial cell types within a transwell system. Two different sets of cells have been developed and processed using the cell printer: a set based on using an immortalised hTERT MSC line to create osteoblasts, chondrocytes and adipocytes, with commercial cells lines providing the other cell types, and a set obtained from tissue excised during orthopaedic surgery. This gives both a repeatable set of cells with which to undertake mode of action studies, and a bank of cell sets which will be representative of different stages of osteoarthritis. The co-cultures have been immunohistochemically assessed in order to demonstrate maintenance of phenotype.

The shoulder is the least constrained of all joints of the body and is more susceptible to injury including dislocation. The rate of recurrent instability following primary stabilization procedure at 10 years of follow-up ranged from 3.4 to 35 %. We describe the outcomes of 74 patients who underwent knotless arthroscopic anterior stabilisation using 1.5 mm Labral Tape with 2.9mm Pushlock anchors for primary anterior instability.

We performed a retrospective analysis of patients who underwent surgery for post-traumatic recurrent anterior instability for 2 years by a single surgeon. Patients with glenoid bone loss, >25% Hill Sachs lesion, posterior dislocation, paediatric age group and multidirectional instability were excluded from this study. Over 90% of our case mix underwent the procedure under regional block anaesthesia and was discharged on the same day. The surgical technique and post-operative physiotherapy was as per standard protocol. Outcomes were measured at 6 months and 12 months. Of the 74 patients in our study, we lost 5 patients to follow up. Outcomes were measured using the Oxford Shoulder Score apart from clinical assessment including the range of motion.

We noted good to excellent outcomes in 66 cases using the Oxford Instability Scores. All patients achieved almost full range of motion at the end of one year. Our cumulative Oxford Instability Score (OIS) preoperatively was 24.72 and postoperatively was 43.09. The Pearson correlation was .28. The t Critical two-tail was 2.07 observing the difference between the means of the OIS. Complications included recurrent dislocation in 2 patients following re-injury and failure of procedure due to recurrent instability requiring an open bone block procedure in one case. We had no reported failures due to knot slippage or anchor pull-out.

We publish the largest case series using this implant with distinct advantages of combining a small bio absorbable implant with flat braided, and high-strength polyethylene tape to diminish the concern for knot migration and abrasive chondral injury with the potential for earlier rehabilitation and a wider footprint of labral compression with comparative outcomes using standard techniques. Our results demonstrate comparable and superior results to conventional suture knot techniques for labral stabilization.

Background

Non-operative cases of mallet finger can be followed up by the hand therapists. Both trust and national policies encourage appropriate indication for follow-up in fracture clinic & cost-effective approach without affecting the patient care.

Introduction

We describe five results of a novel single stage arthroscopic technique for the treatment of articular cartilage defects of the knee. This involves micro drilling and application of Atelo-collagen (Coltrix) and fibrin gel scaffold.

The aim of this study was determine if the detection of pathology in children with a limp can be optimised by screening with blood tests for raised inflammatory markers.

The entry criteria for the study were children (0–15 years) presenting to our hospital Emergency Department from 2012–2015 with a non-traumatic limp or pseudoparalysis of a limb, and no sign of fracture or malignancy on plain radiographs. ESR and CRP blood tests were performed along with other standard investigations. Children with ESR or CRP over 10 underwent MRI scan of their area of pain or tendernesss, with those under 7 years old having general anaesthetic. MRI provided the diagnosis in cases of osteomyelitis, pyomyositis, fasciitis, cellulitis, discitis, as well as non-infective conditions such as malignancy and fracture not visible on plain radiographs. Where a joint effusion was present, the diagnosis of septic arthritis was made from organisms cultured following surgical drainage, or high white cell count in joint fluid if no organisms were cultured. The study was completed once data from 100 consecutive children was available.

64% of children had an infective cause for their symptoms (osteomyelitis, septic arthritis, pyomyositis, fasciitis, cellulitis or discitis). A further 11% had positive findings on MRI from non-infective causes (juvenile idiopathic arthritis, cancer, or occult fracture). The remaining 25% had either a normal scan, or transient synovitis. ESR was a more sensitive marker than CRP, since ESR was raised in 97% of those with abnormal scans, but CRP in only 70%. There were no complications from any of the GA MRI scans. Conclusion: This shows that MRI imaging of all children with a limp and either raised ESR or CRP is a sensitive method to minimise the chance of missing important pathology in this group, and is not wasteful of MRI resources.

Background

Revision surgery for a failed metal on metal (MoM) hip arthroplasty is often unpredictable and challenging due to associated massive soft tissue and bony lesions. We present the analysis and early outcomes of revision surgery in failed MoM hip arthroplasties at our institution.

Background

Two-stage revision is considered the gold standard for treatment of knee prosthetic joint infections. Current guidelines for selecting the most appropriate procedure to eradicate knee prosthetic joint infections are based upon the duration of symptoms, the condition of the implant and soft tissue evaluated during surgery and the infecting organism. A more robust tool to identify candidates for two-stage revision and who are at high risk for treatment failure might improve preoperative risk assessment and increase a surgeon's index of suspicion, resulting in closer monitoring, optimization of risk factors for failure and more aggressive management of those patients who are predicted to fail.

Purpose of the study

We conducted a study to assess the accuracy of Spatial CAD software in computing the mounting and deformity parameters.

Introduction

The ideal method of fixation for femoral components in total hip arthroplasty (THA) is unknown. While good results have been reported for cemented and uncemented components, there is relatively little published prospective data with twenty years or more of follow up.

Results of the Furlong femoral component have been presented at an average of 17 years follow up. We have extended this follow up period to an average of 22.5 years with a minimum of 22 years and a maximum of 25 years.

Purpose

This study investigates the effect of early tourniquet release on range of flexion following total knee replacement, and the influence of anticoagulation with Rivaroxaban and Clexane (Enoxaparin).

Background

Percutaneous K-wire fixation is a well-recognised and often performed method of stabilisation for distal radius fractures. However, there is paucity in the literature regarding the infection rate after percutaneous K-wire fixation for distal radius fractures.

Treatment of a partial laceration in zone two of a flexor tendon remains controversial. The intact part of the tendon can sustain forces of normal un-resisted motion, and repaired partially treated tendons can actually be weaker than un-repaired ones. Trimming these lacerations has been shown to be beneficial in partially lacerated tendons with triggering or entrapment.

The purpose of this study is to observe the behaviour of a partially lacerated and subsequently trimmed tendon under strain, and measure their friction coefficient at different flexion angle and load. Ten long flexor tendons from long digit of turkey foot, along with the equivalent of A2 pulley were used. All experiments were carried out for intact, lacerated (50%) and trimmed tendon at 10, 30, 50 and 70 degrees of flexion and two load settings of 200 and 400g.

The friction forces were measured by the difference between the two load transducers and the friction coefficient was measured using this formula, μ = Ln[(F2/F1)]/Ø.

Friction coefficient (μ), Tension forces (F2 and F1), arc of tendon and pulley contact (Ø).

Results: Friction coefficient increased significantly by three folds (0.3) after laceration compare with intact tendon (0.12) at both loads. This was reduced significantly after trimming the tendon but the friction coefficient was still approximately twice the value of the intact tendon (0.2).

Triggering was noticed in all tendon lacerations. Triggering was reduced after trimming in 10 and 30 degrees of flexion but increased markedly at 50 and 70 degrees of flexion associated with tendon fragmentation at the trimmed area.

Trimming partially lacerated flexor tendons will reduce the gliding resistance of the tendon through the pulley but this can lead to further fragmentation and triggering at higher flexion degrees and loads.

Introduction: Tourniquets are commonly employed in surgical procedures of the knee. The use of the same tourniquet on a repetitive basis without a standard protocol for cleaning has recently been questioned as a potential source of cross-infection. This study examines the contamination of the tourniquets in our institution and results of cleaning the tourniquets with a disinfectant and detergent wipe.

Material and methods: Tryptone soya agar plates were used to take samples from 20 tourniquets employed in knee replacement. Four specified sites on each tourniquet were cultured and incubated at 37° for 48 hrs.

Results: All sampled tourniquets were contaminated with colony counts varying from 9 to > 385.

Coagulase negative Staphylococcus was the most commonly grown organism from the tourniquets (96%).

Some tourniquets had growths of important pathogens including MRSA, Pseudomonas and Staphylococcus aureus (these organisms have not been previously cultured from tourniquets). On cleaning five tourniquets with clinell (detergent and disinfectant) wipes, there was a 99.2% reduction in contamination of the tourniquets five minutes after cleaning.

Conclusion: Contamination is more worrying in relation to pneumatic tourniquets, as they are commonly employed in knee surgery where implants are frequently used with the tourniquet lying within inches of the operative wound.

We have found a 99% reduction in contamination of tourniquets by employing disinfectant wipes. This is a simple, cost-effective and quick method to clean tourniquets and we recommend the use of wipes before every case in addition to the manufactures guidelines for general cleaning of tourniquets.