Autologous cancellous bone graft is the gold standard in large bone defect repair. However, studies using autologous bone grafting in rats are rare and donor sites as well as harvesting techniques vary. The aim of this study was to determine the feasibility of autologous cancellous bone graft harvest from 5 different anatomical sites in rats and compare their suitability as donor sites for autologous bone graft.

13 freshly euthanised rats were used to describe the surgical approaches for autologous bone graft harvest from the humerus, iliac crest, femur, tibia and tail vertebrae (n=4), determine the cancellous bone volume and microstructure of those five donor sites using µCT (n=5), and compare their cancellous bone collected qualitatively by looking at cell outgrowth and osteogenic differentiation using an ALP assay and Alizarin Red S staining (n=4).

It was feasible to harvest cancellous bone graft from all 5 anatomical sites with the humerus and tail being more surgically challenging. The microstructural analysis showed a significantly lower bone volume fraction, bone mineral density, and trabecular thickness of the humerus and iliac crest compared to the femur, tibia, and tail vertebrae. The harvested volume did not differ between the donor sites. All donor sites apart from the femur yielded primary osteogenic cells confirmed by the presence of ALP and Alizarin Red S stain. Bone samples from the iliac crest showed the most consistent outgrowth of osteoprogenitor cells.

The tibia and iliac crest may be the most favourable donor sites considering the surgical approach. However, due to the differences in microstructure of the cancellous bone and the consistency of outgrowth of osteoprogenitor cells, the donor sites may have different healing properties, that need further investigation in an in vivo study.

Post-traumatic osteoarthritis (PTOA) is a subset of osteoarthritis, which occurs secondary to traumatic joint injury which is known to cause pathological changes to the osteochondral unit. Articular cartilage degradation is a primary hallmark of OA, and is normally associated with end-stage disease. However, subchondral bone marrow lesions are associated with joint injury, and may represent localized bone microdamage. Changes in the osteochondral unit have been traditionally studied using explant models, of which the femoral-head model is the most common. However, the bone damage caused during harvest can confound studies of microdamage. Thus, we used a novel patellar explant model to study osteochondral tissue dynamics and mechanistic changes in bone-cartilage crosstalk.

Firstly, we characterized explants by comparing patella with femoral head models. Then, the patellar explants (n=269) were subjected to either mechanical or inflammatory stimulus. For mechanical stimulus 10% strain was applied at 0.5 and 1 Hz for 10 cycles. We also studied the responses of osteochondral tissues to 10ng/ml of TNF-α or IL-1β for 24hrs.

In general the findings showed that patellar explant viability compared extremely well to the femoral head explant. Following IL-1β or TNF-α treatment, MMP13, significantly increased three days post exposure, furthermore we observed a decrease in sulfate glycoaminoglycan (sGAG) content. Bone morphometric analysis showed no significant changes. Contrastingly, mechanical stimulation resulted in a significant decrease sGAG particularly at 0.5Hz, where an increase in MMP13 release 24hrs post stimulation and an upregulation of bone and cartilage matrix degradation markers was observed. Furthermore, mechanical stimulus caused increases in TNF-α, MMP-8, VEGF expression.

In summary, this study demonstrates that our novel patella explant model is an excellent system for studying bone-cartilage crosstalk, which responds well to both mechanical and inflammatory stimulus and is thus of great utility in the study of PTOA.

The use of mesenchymal stromal cells (MSCs) in regenerative medicine and tissue engineering is well established, given their properties of self-renewal and differentiation. However, several studies have shown that these properties diminish with age, and understanding the pathways involved are important to provide regenerative therapies in an ageing population.

In this PRISMA systematic review, we investigated the effects of chronological donor ageing on the senescence of MSCs. We identified 3023 studies after searching four databases including PubMed, Web of Science, Cochrane, and Medline. Nine studies met the inclusion and exclusion criteria and were included in the final analyses.

These studies showed an increase in the expression of p21, p53, p16, ROS, and NF- B with chronological age. This implies an activated DNA damage response (DDR), as well as increased levels of stress and inflammation in the MSCs of older donors. Additionally, highlighting the effects of an activated DDR in cells from older donors, a decrease in the expression of proliferative markers including Ki67, MAPK pathway elements, and Wnt/ -catenin pathway elements was observed. Furthermore, we found an increase in the levels of SA- -galactosidase, a specific marker of cellular senescence.

Together, these findings support an association between chronological age and MSC senescence. The precise threshold for chronological age where the reported changes become significant is yet to be defined and should form the basis for further scientific investigations. The outcomes of this review should direct further investigations into reversing the biological effects of chronological age on the MSC senescence phenotype.

Unicompartmental knee arthroplasty (UKA) is associated with a higher risk of revision compared with total knee arthroplasty (TKA). The outcomes of knee arthroplasty are typically presented as implant survival or incidence of revision after a set number of years, which can be difficult for patients and clinicians to conceptualise. We aimed to calculate the ‘lifetime risk’ of revision for UKA as a more relatable estimate of risk projection over a patient's remaining lifetime, and make comparisons to TKA. All primary UKAS performed from 1999 to 2019 (n=13,481) captured by the New Zealand Joint Registry (NZJR) were included. The lifetime risk of revision was calculated and stratified by age, gender and American Society of Anesthesiologists (ASA) status. The lifetime risk of revision for UKA was highest in the youngest patients (46-50 years; 40.4%) and lowest in the oldest patients (86-90 years; 3.7%). Lifetime risk of revision was higher for females (range 4.3%-43.4% cf. males 2.9%-37.4%) and patients with higher ASA status (ASA 3-4 range 8.8%-41.2% cf. ASA 1 1.8%-29.8%), regardless of age. The lifetime risk of UKA was two-fold higher than TKA (ranging from 3.7%-40.4% UKA, 1.6%-22.4% TKA) across all age groups. Increased risk of revision in the younger patients was associated with aseptic loosening in both males and females, and pain in females. Periprosthetic joint infections (PJI) accounted for 4% of all UKA revisions, in contrast to 27% for TKA; risk of PJI was higher for males than females for both procedures. The lifetime risk of revision is a more meaningful measure of arthroplasty outcomes and can aid with patient counselling prior to UKA. Findings from this study show the increased lifetime risk of UKA revision for younger patients, females and those with higher ASA status.

Anterior vertebral body tethering (AVBT) is a growth modulating procedure used to manage idiopathic scoliosis by applying a flexible tether to the convex surface of the spine in skeletally immature patients. The purpose of this study is to determine the preliminary clinical outcomes for an adolescent patient cohort.

18 patients with scoliosis were selected using a narrow selection criteria to undergo AVBT. Of this cohort, 11 had reached a minimum follow up of 2 years, 4 had reached 18 months, and 3 had reached 6 months. These patients all demonstrated a primary thoracic deformity that was too severe for bracing, were skeletally immature, and were analysed in this preliminary study of coronal plane deformity correction.

Using open-source image analysis software (ImageJ, NIH) PA radiographs taken pre-operatively and at regular follow-up visits post-operatively were used to measure the coronal plane deformity of the major and compensatory curves.

Pre-operatively, the mean age was 12.0 years (S.D. 10.7 – 13.3), mean Sanders score 2.6 (S.D. 1.8-3.4), all Risser 0 and pre-menarchal, with mean main thoracic Cobb angle of 52° (S.D. 44.2-59.8°). Post-operatively the mean angle decreased to 26.4° (S.D. 18.4-32°) at 1 week, 30.4° (S.D. 21.3-39.6°) at 2 months, 25.7° (S.D. 18.7-32.8°) at 6 months, 27.9° (S.D. 16.2-39.6°) at 12 months, and 36.8° (S.D. 22.6– 51.0°) at 18 months and 38.2° (S.D. 27.6-48.7°) at 2 years. The change in curve at 2 years post-operative was statistically significant (P=0.004).

There were 4 tether breakages identified that did not require return to theatre as yet, one patient underwent a posterior spinal instrumented fusion due to curve progression.

AVBT is a promising new growth modulation technique for skeletally immature patients with progressive idiopathic scoliosis. This study has demonstrated a reduction in scoliosis severity.

The objective of this study was to investigate how a new customizable light-curable osteosynthesis method (AdFix) compared to traditional metal hardware when loaded in torsion in an ovine phalanx model.

Twenty-one ovine proximal phalanges were given a 3mm transverse osteotomy and four 1.5mm cortex screws were inserted bicortically on either side of the gap. The light-curable polymer composite was then applied using the method developed by Hutchinson [1] to create osteosyntheses in two groups, having either a narrow (6mm, N=9) or a wide (10mm, N=9) fixation patch. A final group (N=3) was fixated with conventional metal plates. The constructs were loaded in torsion at a rate of 6°/second until failure or 45° of rotation was reached. Torque and angular displacement were measured, torsional stiffness was calculated as the slope of the Torque-Displacement curve, and maximum torque was queried for each specimen.

The torsional stiffnesses of the narrow, wide, and metal plate constructs were 39.1 ± 6.2, 54.4 ± 6.3, and 16.2 ± 3.0 Nmm/° respectively. All groups were statistically different from each other (p<0.001). The maximum torques of the narrow, wide, and metal plate constructs were 424 ± 72, 600 ± 120, and 579 ± 20 Nmm respectively. The narrow constructs were statistically different from the other two (p<0.05), while the wide and metal constructs were not statistically different from each other (p=0.76).

This work demonstrated that the torsional performance of the novel solution is comparable to metal fixators. As a measure of the functional range, the torsional stiffness in the AdhFix exceeded that of the metal plate. Furthermore, the wide patches were able to sustain a similar maximum toque as the metal plates. These results suggest AdhFix to be a viable, customizable alternative to metal implants for fracture fixation in the hand.

Due to their immunomodulatory and regenerative capacity, human bone marrow-derived mesenchymal stromal cells (hBMSCs) are promising in the treatment of polytrauma patients. However, few studies evaluated the effects of sera from polytraumatized patients on hBMSCs. The aim of this study was to explore changes in hBMSCs exposed to serum from polytrauma patients from different time points after trauma.

Sera from 84 patients on day 1 (D1), 5 (D5) and 10 (D10) after polytrauma (ISS ≥ 16) were pooled respectively to test the differential influence on hBMSC. As a control, sera from three healthy age- and gender-matched donors (HS) were collected. The pooled sera were analyzed by Multicytokine Array for pro-/anti-inflammatory cytokines. For the cell culture experiments, hBMSCs from four healthy donors were used. The influence of the different sera on hBMSC regarding cell proliferation, colony forming unit-fibroblast (CFU-F) assay, cell viability and toxicity, cell migration, as well as osteogenic and chondrogenic differentiation was analyzed. One-Way-ANOVA and LSD-test were used for the parametric, Kruskal-Wallis-test for non-parametric data. p≤0.05 was considered as statistically significant.

The results showed that D5 serum reduced hBMSCs cell proliferation capacity by 41.26% (p=0.000) compared with HS and increased the proportion of dead cells by 3.19% (p=0.008) and 2.25% (p=0.020) compared with D1 and D10. The frequency of CFU-F was reduced by 49.08% (p=0.041) in D5 and 53.99% (p=0.027) in D10 compared with HS, whereas the other parameters were not influenced.

The serological effect of polytrauma on hBMSCs was related to the time after trauma. It is disadvantageous to use BMSCs in polytraumatized patients five days after the incidence as obvious cytological changes could be found at that time point. However, it is promising to use hBMSCs to treat polytrauma after 10 days, combined with the concept of “Damage Control Orthopaedics” (DCO).

To quantify bone-nail fit in response to varying nail placements by entry point translation in straight antegrade humeral nailing using three-dimensional (3D) computational analysis

CT scans of ten cadaveric humeri were processed in 3D Slicer to obtain 3D models of the cortical and cancellous bone. The bone was divided into individual slices each consisting of 2% humeral length (L) with the centroid of each slice determined. To represent straight antegrade humeral nail, a rod consisting of two cylinders with diameters of 9.5mm and 8.5mm and length of 0.22L mm and 0.44L mm respectively joined at one end was modelled. The humeral head apex (surgical entry point) was translated by 1mm in both anterior-posterior and medio-lateral directions to generate eight entry points. Total nail protrusion surface area, maximum nail protrusion distance into cortical shell and top, middle, bottom deviation between nail and intramedullary cavity centre were investigated. Statistical analysis between the apex and translated entry points was conducted using paired t-test.

A posterior-lateral translation was considered as the optimal entry point with minimum protrusion in comparison to the anterior-medial translation experiencing twice the level of protrusion. Statistically significant differences in cortical protrusion were found in anterior-medial and posterior-lateral directions producing increased and decreased level of protrusion respectively compared to the apex. The bottom anterior-posterior deviation distance appeared to be a key predictor of cortical breach with the distal nail being more susceptible. Furthermore, nails with anterior translation generated higher anterior-posterior deviation (>4mm) compared to posterior translation (<3mm).

Aside from slight posterolateral translation of the entry point from the apex, inclusion of a distal posterior-lateral bend into current straight nail design could improve nail fitting within the curved humeral bone, potentially improving distal working length within the flat and narrow medullary canal of the distal humeral shaft.

Recent researches indicate that both M1 and M2 macrophages play vital roles in tissue repair and foreign body reaction processes. In this study, we investigated the dynamics of M1 macrophages in the induced membrane using a mouse femur critical-sized bone defect model.

The Masquelet method (M) and control (C) groups were established using C57BL/6J male mice (n=24). A 3mm-bone defect was created in the right femoral diaphysis followed by a Kirschner wire fixation, and a cement spacer was inserted into the defect in group M. In group C, the bone defect was left uninserted. Tissues around the defect were harvested at 1, 2, 4, and 6 weeks after surgery (n=3 in each group at each time point). Following Hematoxylin and eosin (HE) staining, immunohistochemical staining (IHC) was used to evaluate the CD68 expression as a marker of M1 macrophage. Iron staining was performed additionally to distinguish them from hemosiderin-phagocytosed macrophages.

In group M, HE staining revealed a hematoma-like structure, and CD68-positive cells were observed between the spacer and fibroblast layer at 1 week. The number of CD68-positive cells decreased at 2 weeks, while they were observed around the new bone at 4 and 6 weeks. In group C, fibroblast infiltration and fewer CD68-positive cells were observed in the bone defect without hematoma-like structure until 2 weeks, and no CD68-positive cells were observed at 4 and 6 weeks. Iron staining showed hemosiderin deposition in the surrounding area of the new bone in both groups at 4 and 6 weeks. The location of hemosiderin deposition was different from that of macrophage aggregation.

This study suggests that M1 macrophage aggregation is involved in the formation of induced membranes and osteogenesis and may be facilitated by the presence of spacers.

To conduct a meta-analysis for intertrochanteric hip fractures comparing in terms of efficacy and safety short versus long intralomedullary nails.

A pubmed search of the last 10 years for intertrochanteric fracture 31A1-31A3 according to the AO/OTA classification was performed. Baseline characteristics of each article were obtained, complication measures were analyzed: Peri-implant fracture, reoperations, deep/superficial infection, and mortality. Clinical variables consisted of blood loss (mL), length of stay (days), time of surgery (min) and nº of transfusions. Functional outcomes were also recorded. A meta-analysis was performed with Review Manager 5.4.

Twelve studies were included, nine were retrospective. The reoperations rate was lower in the short nail group and the peri-implant fracture rate was lower in the long nail group (OR 0.58, 95% CI 0.38 to 0.88) (OR 1.88, 95% CI 1.04 to 3.43). Surgery time and blood loss was significantly higher in the long nail group (MD −12.44, 95% CI −14.60 to −10.28) (MD −19.36, 95% CI −27.24 to −11.48). There were no differences in functional outcomes.

The short intramedullary nail has a higher risk of peri-implant fracture; however, the reoperation rate is lower compared to the long nail. Blood loss and surgery time was higher in the long nail group.

Total knee arthroplasty is one of the most common surgeries. About 92% of all implanted knee endorposthesis in 2020 were manufactured from uncoated CoCrMo articulating on ultra-high-molecular-weight polyethylene. All articluations generate wear particles and subsequent emission of metal ions due to the mechanical loading. These wear particles cause diverse negative reactions in the surrounding tissues and can lead to implant loosening. Coating technologies might offer the possibility to reduce this wear. Therefore, we investigated the applicability of tetrahedral amorphous carbon (ta-C) coating on CoCrMo alloy.

Polished specimens made of CoCrMo wrought alloy according to ISO 5832-12 were coated with ta-C coatings with different layer structure using pulsed laser deposition (PLD). This process allows the deposition of ta-C coatings with low internal stress using an additional relaxation laser. Surface quality and mechanical properties of the coating were characterised using optical surface measurements (NanoFocus μsurf expert, NanoFocus AG) and a nanoindentation tester NHT³ (Anton Paar GmbH). Scratch tests were performed on Micro Scratch Tester MST³ (Anton Paar TriTec SA) to define the coating adhesion. Pin-on-plate tribological tests, with a polyethylene ball sliding on the ta-C-coated plate under a defined load according to ISO 14243-1 were performed using a linear tribometer (Anton Paar GmbH) to evaluate the tribological and wear properties.

The ta-C coatings showed a mean roughness Ra of 5-20 nm and a hardness up to 60 GPa (n=3). The adhesion of the ta-C coatings (n=3) was comparable to the commercial coatings like TiN and TiNbN. The pin-on-plate tests showed an improvement of tribological properties in comparison with the polished uncoated CoCrMo specimens (n=3).

The ta-C coatings applied by DLP technology show increased hardness compared to the base material and sufficient adhesion. Further research will be needed to investigate the optimal coating strategy for implant coating.

Design of bone tissue engineering scaffolds imposes a number of requirements for their physical properties, in particular porosity and mechanical behaviour. Alginates are known as a potential material for such purposes, usually deploying calcium as a cross-linker. Calcium over-expression was reported having proinflammatory effect, which is not always desirable. Contrary to this, barium has better immunomodulatory outcome but data for barium as a cross-linker are scarce. In this work the objective was to produce Ba-linked alginates and compare their viscoelastic properties with Ca-linked controls in vitro.

Sodium alginate aqueous solution (1 wt%) with 0.03 wt.% CaCl₂ is gelled in dialysis tubing immersed in 27 mM CaCl₂ (controls) or BaCl₂, for 48 h, followed by freeze-drying and rehydration (with 0.3 wt.% CaCl₂ and 0.8 wt.% NaCl). Hydrogel discs (diameter 8-10 mm, thickness 4-6 mm) were assessed in dry and wet (DMEM immersed) states by dynamic mechanical analysis (DMA) under compressive creep conditions with increased loads, frequency scans and strain-controlled sweeps in physiological range (0.1-20 Hz) at 25°C and 37°C. Resulting data were analysed by conventional methods and by a model-free BEST (Biomaterials Enhanced Simulation Testing) to extract invariant values and material functions.

Significant differences were observed in properties of Ba-linked hydrogel scaffolds vs. Ca-linked controls. Specifically, for the similar porosity Ba-samples exhibited lower creep compliance, higher dynamical stiffness and lower loss factor in the whole studied range. Invariant modulus exhibited a non-linear decay vs. applied stress. These differences were observed in both dry and wet states and temperatures.

Use of barium as a cross-linker for alginates allows further modification of biomechanical properties of the scaffolds for better compliancy to the tissues in the application. Barium release might have an immunomodulating effect but also promote ion exchange for osteogenesis due to additional Ca/Ba concentration gradient.

Although autografts represent the gold standard for anterior cruciate ligament (ACL) reconstruction, tissue-engineered ACLs provide a prospect to minimize donor site morbidity and limited graft availability. This given study characterizes the ligamentogenesis in embroidered poly(L-lactide-co-ε-caprolactone) (P(LA-CL)) / polylactic acid (PLA) constructs using a dynamic nude mice xenograft model. (P(LA-CL))/PLA scaffolds remained either untreated (co) or were functionalized by gas fluorination (F), collagen foam cross-linked with hexamethylene diisocyanate (HMDI) (coll), or gas fluorination combined with the foam (F+coll). Cell free constructs or those seeded for 1 week with lapine ACL ligamentocytes were implanted into nude mice for 12 weeks. Following explantation, biomechanical properties, cell vitality and content, histopathology of scaffolds (including organs: liver, kidney, spleen), sulphated glycosaminoglycan (sGAG) contents and biomechanical properties were assessed.

Implantation of the scaffolds did not negatively affect mice weight development and organs, indicating biocompatibility. All scaffolds maintained their size and shape for the duration of the implantation. A high cell viability was detected in the scaffolds prior to and following implantation. Coll or F+coll scaffolds seeded with cells yielded superior macroscopic properties when compared to the controls. Mild signs of inflammation (foreign-body giant cells, hyperemia) were limited to scaffolds without collagen. Microscopical score values and sGAG content did not differ significantly. Although remaining stable in vivo, elastic modulus, maximum force, tensile strength and strain at Fmax were significantly lower in the in vivo compared to the samples cultured 1 week in vitro, but did not differ between scaffold subtypes, except for a higher maximum force in F+coll compared with F samples (in vivo). Scaffold functionalization with fluorinated collagen foam provides a promising approach for ACL tissue engineering.

(shared first authorship)

Acknowledgement: The study was supported by DFG grants SCHU1979/9-1 and SCHU1979/14-1.

To ensure clinical relevance, the in vitro engineering of tissues for implantation requires artificial replacements to possess properties similar to native anatomy. Our overarching study is focussed on developing a bespoke bone-tendon in vitro model replicating the anatomy at the flexor digitorum profundus (FDP) tendon insertion site at the distal phalanx. Anatomical morphometric analysis has guided FDP tendon model design consisting of hard and soft tissue types. Here, we investigate potential materials for creation of the model's bone portion by comparison of two bone cements; brushite and genex (Biocomposites Ltd).

3D printed molds were prepared based on anatomical morphometric analysis of the FDP tendon insertion site and used to cast identical bone blocks from brushite and genex cements. Studies assessing the suitability of each cement type were conducted e.g. setting times, pH on submersion in culture medium and interaction with fibrin gels. Data was collected using qualitative imaging and qualitative measurements (N=3,n=6) for experimental conditions.

Both brushite (BC) and genex (GC) cements could be cast into bespoke molds, producing individual blocks and were mixed/handled with appropriate setting times. On initial submersion in culture medium, BC caused a reduction in pH values (7.49 [control]) to 6.85) while GC remained stable (7.59). Reduction in pH value also affected fibrin gel interaction where gel was seen to be detaching/not forming around BC and medium discolouration was noted. This was not observed in GC. While GC outperformed BC in initial tests, repeated washing of BC led to pH stabilisation (7.5,3xwashes), consistent with their further use in this model.

This study has compared BC and GC as materials for bone block production. Both materials show promise, and current work assessing material properties and cell proliferation are needed to inform our choice for use in our FDP-tendon-bone interface model.

This research was supported by an ORUK Studentship award (ref:533). Genex was kindly provided by Biocomposites, Ltd.

Meniscal tears are the most common injury in the knee, affecting 66/100,000 people/year. Surgical treatment includes arthroscopic meniscectomy or meniscal repair. Little is known regarding medium-term outcomes following these procedures in isolated meniscal tears. This study aims to quantitatively evaluate patients with meniscal tears, and those who have undergone meniscectomy and meniscal repair using validated patient reported outcome measures (PROMs), further exploring factors which affect surgical outcomes.

This observational study screened 334 patients who underwent arthroscopic surgery at South Tyneside Hospital since August 2013. 134 patients with isolated meniscal tears were invited to complete postal PROMs. A combination of patient notes and radiological imaging was used to collect information of interest including age, gender, knee-laterality, injured meniscus, tear pattern, procedure performed, complications, and associated injuries.

A total of 115 patients (pre-operative patients with current meniscal tear (n=36), meniscectomy (n=63), meniscal repair (n=16)) were included in the analysis with 96% successful PROM completion. Both meniscectomy and meniscal repairs (mean 55-months follow-up) showed better outcomes than pre-operative patients with meniscal tears. Meniscal repairs demonstrated superior outcomes across all PROMs when compared to meniscectomy, with a greater mean overall KOOS score of 17.2 (p=0.009). Factors including higher pre-operative Kellgren-Lawrence Grade, pre-operative articular cartilage lesions and bilateral meniscectomies were shown to negatively influence outcomes.

Both meniscectomy and meniscal repair maintain clinical benefit at mean 55-months follow-up, affirming their use for treatment of meniscal tears. When feasible, meniscal repair should be performed preferentially over meniscectomy in isolated meniscal tears. Identified predictive factors allow adequate treatment stratification in specific patient groups.

A hot swollen joint is a commonly encountered condition in clinical practice. With a broad range of differentials, septic arthritis (SA) is perhaps one of the most concerning. Treated by culture-specific antibiotics and arthroscopic lavage, some patients require multiple washouts. We aimed to determine:

(1) What are the risk factors for development of SA?

(2) What are the risk factors for repeat washout in SA patients?

(3) What are the important clinical differences between a periprosthetic joint infection (PJI) and SA cohort?

All patients presenting to the emergency department, orthopaedic, and rheumatology clinics between January 2020 to January 2021 with a hot, swollen joint were retrospectively evaluated. Patients with previous trauma on the ipsilateral joint, with data missing from their medical records in any of the variables required for analysis, <24 months follow-up were excluded.

Variables of interest in the three-month period preceding the diagnosis of SA were compared between SA and non-SA patients. Factors with a p-value of p<0.100 in univariate analysis were included in a stepwise multivariate logistic regression model. Similar analyses were performed to compare SA patients with multiple washouts with those needing one washout. Demographical and clinical data for PJI patients were collected to delineate important differences with SA cohort.

211 patients were included (SA:28;PJI:24;pseudogout:32;gout:26;others:101). Multivariate analysis showed rheumatoid arthritis (RA), skin infection, and liver disease were risk factors for SA. Amongst patients with septic arthritis, multivariate analysis showed that WBC levels above normal limits (3.6-10.5×109 cells/L) and RA were risk factors for multiple washouts.

Between the SA and PJI cohorts, BMI (p=0.002) was significantly lower in the former, whilst WBC level (p=0.023) and CRP (p<0.0001) was significantly higher in the former.

Early diagnosis of septic arthritis requires understanding the risk factors, namely RA, skin infection, and liver disease. Considering PJI and septic arthritis as the same entity can lead to wrong clinical judgement, and clinicians should be aware of important differences. We believe that the models in this study are of prognostic value to clinicians who are presented with the common presenting compliant of a hot swollen joint.

In this study, we aimed to investigate tibiofemoral and allograft loading parameters after OCA transplantation using tibial plateau shell grafts to characterize the clinically relevant biomechanics that may influence joint kinematics and OCA osseointegration after transplantation. The study was designed to test the hypothesis that there are significant changes in joint loading after tibial plateau OCA transplantation that may require unique post-operative rehabilitation regimens in patients to restore balance in the knee joint.

Fresh-frozen cadaveric knees (n=6) were thawed and mounted onto a 6 DOF KUKA robot. Specimens were size matched to +2 mm for the medial-to-lateral width of the medial tibial hemiplateaus. Three specimens served as allograft recipient knees and three served as donor knees. Recipient knees were first tested in their native state and then tested with size-matched medial tibial hemiplateau shell grafts (n=3) prepared from the donor knees using custom-cut tab-in-slot and subchondral drilling techniques. Tekscan sensors were placed in the joint spaces to evaluate the loading conditions under 90N biaxial loading at full extension of the knee before and after graft placement. The I-Scan system used in conjunction analyzed the total force, pressure distribution, peak pressure, and center of force within the joint space.

Data demonstrated significant difference (p<0.05) in joint space loading after graft implantation compared to controls in both lateral and medial tibial plateaus. The I-Scan pressure mapping system displayed changes in femoral condylar contact points as well.

The results demonstrated that joint space loading was significantly different (p<0.05) between all preoperative and postoperative cadaveric specimens. Despite the best efforts to size match grafts, slight differences in the host's joint geometry resulted in shifts of contact areas between the tibial plateau and femoral condyle therefore causing either an increase or decrease in pressure measured by the sensor. This concludes that accuracy in graft size matching is extremely important to restoring close to normal loading across the joint and this can be further ensured through postoperative care customized to the patient after OCA surgery.

Osteoarthritis, the most common degenerative joint disease, significantly impairs life quality and labor capability of patients. Synovial inflammation, initiated by HMGB1 (High mobility group box 1)-induced activation of macrophage, precedes other pathological changes. As an upstream regulator of NF-κB (nuclear factor-kappa B) and MAPK (mitogen-activated protein kinase) signaling pathway, TAK1 (TGF-β activated kinase 1) participates in macrophage activation, while its function in osteoarthritis remains unveiled. This study aims to investigate the role of TAK1 in the pathogenesis of osteoarthritis via both in vitro and in vivo approaches.

We performed immunohistochemical staining for TAK1 in synovial tissue, both in osteoarthritis patients and healthy control. Besides, immunofluorescence staining for F4/80 as macrophage marker and TAK1 were conducted as well. TAK1 expression was examined in RAW264.7 macrophages stimulated by HMGB1 via qPCR (Quantitative polymerase chain reaction) and Western blotting, and the effect of TAK1 inhibitor (5z-7 oxozeaenol) on TNF-α production was evaluated by immunofluorescence staining. Further, we explored the influence of intra-articular shRNA (short hairpin RNA) targeting TAK1 on collagenase-induced osteoarthritis in mice.

Immunohistochemical staining confirmed significant elevation of TAK1 in osteoarthritic synovium, and immunofluorescence staining suggested macrophages as predominant residence of TAK1. In HMGB1-stimulated RAW264.7 macrophages, TAK1 expression was up-regulated both in mRNA and protein level. Besides, TAK1 inhibitor significantly impairs the production of TNF-α by macrophages upon HMGB1 stimulation. Moreover, intra-articular injection of lentivirus loaded with shRNA targeting TAK1 (sh-TAK1) reduced peri-articular osteophyte formation in collagenase-induced osteoarthritis in mice.

TAK1 exerts a potent role in the pathogenesis of osteoarthritis by mediating the activation of macrophages.

Periprosthetic joint infections (PJI) are one of the most common reasons for orthopedic revision surgeries. In previous studies, it has been shown that silver modification of titanium (Ti-6Al-4V) surfaces by PMEDM (powder mixed electrical discharge machining) has an antibacterial effect on Staphylococcus aureus adhesion. Whether this method also influences the proliferation of bacteria has not been investigated so far. Furthermore, the effect is only limitedly investigated on the ossification processes. Therefore, the aim of this work is to investigate the antibacterial effect as well as the in vitro ossification process of PMEDM machined surfaces modified by integration of silver.

In this study, we analyzed adhesion and proliferation of S. aureus in comparison to of surface roughness, silver content and layer thickness of the silver-integrated-PMEDM surfaces (N = 5). To test the in vitro ossification, human osteoblasts (SaOs-2) and osteoclasts (differentiated from murine-bone-marrow-macrophages) were cultured on the silver surfaces (N = 3).

We showed that the attachment of S. aureus on the surfaces was significantly lower than on the comparative control surfaces of pure Ti-6Al-4V without incorporated silver, independently of the measured surface properties. Bacterial proliferation, however, was not affected by the silver content. No influence on the in vitro ossification was observed, whereas osteoclast formation was drastically reduced on the silver-modified surfaces.

We showed that 1 to 3% of silver in the surface layer significantly reduced the adhesion of S. aureus, but not the proliferation of already attached bacteria. At the same time, no influence on the in vitro ossification was observed, while no osteoclasts were formed on the surface. Therefore, we state that PMEDM with simultaneous silver modification of the machined surfaces represents a promising technology for endoprostheses manufacturing to reduce infections while at the same time optimizing bone ingrowth.

The implantation of endoprosthesis is a routine procedure in orthopaedics. Endoprosthesis are mainly manufactured from ceramics, polymers, metals or metal alloys. To ensure longevity of the implants they should be as biocompatible as possible and ideally have antibacterial properties, to avoid periprosthetic joint infections (PJI). Various antibacterial implant materials have been proposed, but have so far only been used sporadically in patients. PJI is one of the main risk factors for revision surgeries. The aim of the study was to identify novel implant coatings that both exhibit antibacterial properties whilst having optimal biocompatibility.

Six different novel implant coatings and surface modifications (EBM TiAl6V4, strontium, TiCuN, TiNbN, gentamicin phosphate (GP), gentamicin phosphate+cationic polymer (GP+CP)) were compared to standard CoCrMo-alloy. The coatings were further characterized with regard to the surface roughness. E. coli and S. capitis were cultured on the modified surfaces to investigate the antibacterial properties. To quantify bacterial proliferation the optical density (OD) was measured and viability was determined using colony forming units (CFU). Murine bone marrow derived macrophages (BMMs) were cultured on the surfaces and differentiated into osteoblasts to quantify the mineralisation using the alizarin red assay.

All novel coatings showed reduced bacterial proliferation and viability compared to standard CoCrMo-alloy. A significant reduction was observed for GP and GP+CP coated samples compared to CoCrMo (OD_GP,E.coli = 0.18±0.4; OD_GP+CP,E.coli = 0.13±0.3; p≤0.0002; N≥7-8). An increase in osteoblast-mediated mineralisation was observed on all surfaces tested compared to CoCrMo. Furthermore, GP and GP+CP coated samples showed a statistically significant increase (M_GP = 0.21±0.1; M_GP+CP = 0.25±0.2; p<0.0001; N≥3-6).

The preliminary data indicates that the gentamicin containing surfaces have the most effective antibacterial property and the highest osseointegrative capacity. The use of antibiotic coatings on prostheses could reduce the risk of PJI while being applied on osseointegrative implant surfaces.

Recently, several smartphone applications (apps) have been developed and validated for ankle ROM measurement tools like the universal goniometer. This is the first innovative study introduces a new smartphone application to measure ankle joint ROM as a remote solution. This study aimed to assess the correlation between smartphone ROM and universal goniometer measurements, and also report the evaluation of the DijiA app by users.

The study included 22 healthy university students (14F/8M; 20.68±1.72 years) admitted to Yeditepe University. Fourty four feet was measured by both the universal goniometer (UG) and DijiA app. The datas were analyzed through using the intraclass correlation coefficient (ICC). The DijiA app was evaluated by usability testing with representative users.

Pearson correlation coefficient test showed moderate correlation between the DijiA and UG for dorsiflexion (DF) and plantar flexion (PF) measurements (Pearson correlation coefficient: r=0.323, for DF; r=0.435 for PF 95% confidence interval). The application usability was found as high with 76.5 average score and users liked it.

The DijiA app may be a more convenient and easy way to measure ankle DF and PF-ROM than UG. It can be used to evaluate ROM in clinical practice or home using as a personal smartphone.

C. Difficile infections in elderly patients with hip fractures is associated with high morbidity and mortality. Antibiotic regimens with penicillin and its derivatives is a leading cause. Antibiotic prophylactic preferences vary across different hospitals within NHS. We compared two antibiotic prophylactic regimens - Cefuroxime only prophylaxis and Teicoplanin with Gentamicin prophylaxis in fracture neck of femur surgery, and evaluated the incidence of C. Difficile diarrhea and Surgical Site Infection (SSI).

To assess the Surgical Site Infection and C. Difficile infection rate associated with different regimens of antibiotics prophylaxis in fracture neck of femur surgery.

Data was analyzed retrospectively. Neck of femur fracture patients treated surgically from 2009 in our unit were included. Age, gender, co morbidities, type of fracture, operation, ASA grade was collected. 1242 patients received Cefuroxime only prophylaxis between January 2009 and December 2012 (Group 1) and 486 patients received Teicoplanin with Gentamicin between October 2015 and March 2017 (Group 2). There were 353 males and 889 female patients in Group 1 and 138 males and 348 female patients in Group 2. The co morbidities in both groups were comparable. Incidence of C. Difficile diarrhea and Surgical Site Infection (SSI) was noted. Statistical analysis with chi square test was performed to determine the ‘p’ value.

C. Diff diarrhea rate in Group 2 was 0.41 % as compared to 1.29 % in Group 1. The Surgical Site Infection (SSI) rate in Group 2 was 0.41 % as compared to 3.06 % in Group 1. The comparative results were statistically significant (p = 0.0009).

Prophylactic antibiotic regimen of Teicoplanin with Gentamicin showed significant reduction in C. Difficile diarrhea & Surgical Site Infection in fracture neck of femur patients undergoing surgery.

Cannulated hip screws are frequently used in the management of hip fractures. There have been concerns over the failure rate of the technique and the outcomes of those that subsequently require conversion to total hip replacement (THR).

This study utilised a database of over 600 cannulated hip screw (CHS) fixations performed over a 14-year period and followed up for a minimum of one year (1-14). We identified 57 cases where a conversion to THR took place (40 females, 17 males, mean age: 71.2 years). Patient demographics, original mechanism of injury, fracture classification, reason for fixation failure, time until arthroplasty, implant type and post-arthroplasty complications were recorded. Clinical outcomes were measured using the Oxford Hip Score.

The failure rate of cannulated screw treatment was 9.4% and the mean time from initial fixation to arthroplasty was 15.4 (16.5) months. Thirty six fractures were initially undisplaced and 21 were displaced. As one might expect the displaced cases tended to be younger but this didn't reach statistical significance [66.5(14.3) vs 72.7(13.1), p=0.1]. The commonest causes of failure were non-union (25 cases, 44%) and avascular necrosis (17 cases, 30%). Complications after THR consisted of one leg length discrepancy and one peri-prosthetic fracture. The mean Oxford score pre-arthroplasty was 12.2 (8.4), improving to 38.4 (11.1) at one-year. Although the pre op Oxford scores tended to be lower in patients with undisplaced fractures and higher ASA scores, the improvement was the same whatever the pre-op situation. The one-year Oxford score and the improvement in score are comparable to those seen in the literature for THR in general.

In conclusion, CHS has a high success rate and where salvage arthroplasty is required it can provide good clinical outcomes with low complication rates.

Total hip replacement (THR) is indicated for patients with osteoarthritis where conservative treatment has failed. Metal alloys used in THR implants such as cobalt-chromium (CoCr) have been known to cause pro-inflammatory reactions in patients, therefore leading to the need for costly revision surgery. This study therefore aimed to investigate the role of TLR4 in the activation of a human osteoblast model in response to CoCr particles in vitro.

Human osteoblasts (MG-63 cell line) were seeded at a density of 100,000 cells and treated with 0.5, 5, 50mm3 CoCr particles per cell for 24-hours. Trypan blue and the XTT Cell Proliferation Kit II were then used in conjunction with the cells to assess CoCr-induced cytotoxicity. Cells were pre-treated with a commercially available TLR4-specific small molecule inhibitor (CLI-095) for 6 hours. Untreated cells were used as a negative control and lipopolysaccharide (LPS) was used as a positive control. Following treatment the cell supernatant was collected and used for enzyme-linked immunosorbant assay (ELISA) to measure the secretion of interleukin-8 (IL-8), CXCL10, and interleukin-6 (IL-6).

Trypan blue and XTT analysis showed that there was no significant changes to cell viability or proliferation at any dose used of CoCr after 24 hours. There was a significant increase in protein secretion of IL-8 (p<0.001), CXCL10 (p<0.001), and IL-6 (p<0.001) in the cells which received the highest dosage of CoCr. This pro-inflammatory secretory response was ameliorated by TLR4 blockade (p<0.001).

CoCr particles are not cytotoxic to osteoblasts but they do induce pro-inflammatory changes as characterised by increased secretion of chemokines IL-8, CXCL10, and IL-6. These responses occur via a TLR4-mediated pathway and upon inhibition they can be effectively ameliorated. This is particularly important as TLR4 could be a potential target for pharmacological intervention used in patients experiencing immunological reactions to metal implant debris.

Plantar fasciitis (PF) is one of the widespread conditions causing hindfoot pain. The most common presenting symptoms are functional limitation and pain (first step and activity) on plantar surface of the foot. The non-operative treatments provide complete resolution of pain in 90% of patients, but functional limitation still remains as a risk factor for recurrency of PF. Although the number of non-operative treatment options showing efficacy on pain and functional limitation are excessive, the evidences are limited for functional limitation. Additionally, Mulligan mobilization with movement (MMWM) in Chronic Plantar Fasciitis has been poorly studied in the literature. According to these findings, the study was aimed to determine effectiveness of Mulligan mobilization with movement on Chronic Plantar Fasciitis.

A total of 25 patients (40 feet) with chronic PF were included in the study. The patients were randomly divided into Mulligan concept rehabilitation group (PF-M, n=20 feet) and Home Rehabilitation group (PF-H, n=20 feet). (MMWM), Foot and ankle exercises program were applied to PF-M, twice a week totally 8 week (16 sessions) and foot- ankle exercises as a home program were given for PF-H, 8 weeks. The range of motion (ROM) for dorsiflexion and plantar flexion was measured by using a manual goniometer. Pain, disability and activity restriction were assessed by Foot Function Index (FFI) . The first step morning pain was evaluated by Visual Analogue Scale (VAS) and Kinesiophobia was also reported by using Tampa Scale (TSK). Patients were evaluated at baseline and 8 weeks.

FFI, VAS, TSK, ROM values improved in all groups (intragroup variability) at 8th week (P < .05). The other result indicated that ROM values for DF and PF and TSK scores in PF-M had more significant improvement than PF-H (p<.05).

To the best of our knowledge this is the first randomised controlled trial for investigating Mulligan Concept efficiancy on chronic PF. Both Mulligan mobilization with movement (MMWM) and exercise protocols are effective for chronic PF. Furthermore, The Mulligan concept seems more effective treatment option in reducing kinesiophobia and improving functional capacity.

An increased number of neutrophils (NEUs) has long been associated with infections in the knee joints; their contribution to knee osteoarthritis (KOA) pathophysiology remains largely unexplored. This study aimed to compare the phenotypic and functional characteristics of synovial fluid (SF)-derived NEUs in KOA and knee infection (INF).

Flow cytometric analysis, protein level measurements (ELISA), NEU oxidative burst assays, detection of NEU phagocytosis (pHrodo^TM Green Zymosan Biparticles^TM Conjugate for Phagocytosis), morphological analysis of the SF-derived/synovial tissue NEUs, and cultivation of human umbilical vein endothelial cells (HUVECs) using SF supernatant were used to characterise NEUs functionally/morphologically.

Results: Compared with INF NEUs, KOA NEUs were characterised by a lower expression of CD11b, CD54 and CD64, a higher expression of CD62L, TLR2 and TLR4, and lower production of inflammatory mediators and proteases, except CCL2.

Functionally, KOA NEUs displayed an increased production of radical oxygen species and phagocytic activity compared with INF NEUs. Morphologically, KOA and INF cells displayed different cell sizes and morphology, histological characteristics of the surrounding synovial tissues and influence on endothelial cells. KOA NEUs were further subdivided into two groups: SF containing <10% and SF with 10%–60% of NEUs. Analyses of two KOA NEU subgroups revealed that NEUs with SF <10% were characterised by 1) higher CD54, CD64, TLR2 and TLR4 expression on their surface; 2) higher concentrations of TNF-α, sTREM-1, VILIP-1, IL-1RA and MMP-9 in SFs.

Our findings reveal a key role for NEUs in the pathophysiology of KOA, indicating that these cells are morphologically and functionally different from INF NEUs. Further studies should explore the mechanisms that contribute to the increased number of NEUs and their crosstalk with other immune cells in KOA.

This study was supported by the Ministry of Health of the Czech Republic (NU20-06-00269; NU21-06-00370).

Odontoid fracture of the second cervical vertebra (C2) is the most common spinal fracture type in elderly patients. However, very little is known about the biomechanical fracture mechanisms, but could play a role in fracture prevention and treatment. This study aimed to investigate the biomechanical competence and fracture characteristics of the odontoid process.

A total of 42 human C2 specimens (14 female and 28 male, 71.5 ± 6.5 years) were scanned via quantitative computed tomography, divided in 6 groups (n = 7) and subjected to combined quasi-static loading at a rate of 0.1 mm/s until fracturing at inclinations of −15°, 0° and 15° in sagittal plane, and −50° and 0° in transverse plane. Bone mineral density (BMD), specimen height, fusion state of the ossification centers, stiffness, yield load, ultimate load, and fracture type according to Anderson and d'Alonzo were assessed.

While the lowest values for stiffness, yield, and ultimate load were observed at load inclination of 15° in sagittal plane, no statistically significant differences could be observed among the six groups (p = 0.235, p = 0.646, and p = 0.505, respectively). Evaluating specimens with only clearly distinguishable fusion of the ossification centers (n = 26) reveled even less differences among the groups for all mechanical parameters. BMD was positively correlated with yield load (R² = 0.350, p < 0.001), and ultimate load (R² = 0.955, p < 0.001), but not with stiffness (p = 0.070). Type III was the most common fracture type (23.5%).

These biomechanical outcomes indicate that load direction plays a subordinate role in traumatic fractures of the odontoid process in contrast to BMD which is a strong determinant of stiffness and strength. Thus, odontoid fractures appear to result from an interaction between load magnitude and bone quality.

Tip-apex distance (TAD) has long been discussed as a metric for determining risk of failure in fixation of peritrochanteric hip fractures. This study seeks to investigate risk factors including TAD for hospital readmission one year after hip fixation surgery.

A retrospective review of proximal hip fractures treated with single screw intramedullary devices between 2016 and 2020 was performed at a 327 bed regional medical center. Patients included had a postoperative follow-up of at least twelve months or surgery-related complications developing within that time.

44 of the 67 patients in this study met the inclusion criteria with adequate follow-up post-surgery. The average TAD in our study population was 19.57mm and the average one year readmission rate was 15.9%. 3 out of 6 patients (50%) with a TAD > 25mm were readmitted within one year due to surgery-related complications. In contrast, 3 out of 38 patients (7.9%) with a TAD < 25mm were readmitted within one year due to surgery-related complications (p=0.0254). Individual TAD measurements, averaging 22.05mm in patients readmitted within one year of surgery and 19.18mm in patients not readmitted within one year of surgery were not significantly different between the two groups (p=0.2113).

Our data indicate a significant improvement in hospital readmission rates up to one year after hip fixation surgery in patients with a TAD < 25mm with a decrease in readmissions of over 40% (50% vs 7.9%). This result builds upon past investigations by extending the follow-up time to one year after surgery and utilizing hospital readmissions as a metric for surgical success. With the well-documented physical and financial costs of hospital readmission after hip surgery, our study highlights a reduction of TAD < 25mm as an effective method of improving patient outcomes and reducing financial costs to patients and medical institutions.

Residual tumor cells left in the bone defect after malignant bone tumor resection can result in local tumor recurrence and high mortality. Therefore, ideal bone filling materials should not only aid bone reconstruction or regeneration, but also exert local chemotherapeutic efficacy. However, common bone substitutes used in clinics are barely studied in research for local delivery of chemotherapeutic drugs. Here, we aimed to use facile manufacturing methods to render polymethylmethacrylate (PMMA) cement and ceramic granules suitable for local delivery of cisplatin to limit bone tumor recurrence.

Porosity was introduced into PMMA cement by adding 1-4% carboxymethylcellulose (CMC) containing cisplatin, and chemotherapeutic activity was rendered to two types of granules via adsorption. Then, mechanical properties, porosity, morphology, drug release kinetics, ex vivo reconstructive properties of porous PMMA and in vitro anti-cancer efficacy against osteosarcoma cells were assessed. Morphologies, molecular structures, drug release profiles and in vitro cytostatic effects of two different drug-loaded granules on the proliferation of metastatic bone tumor cells were investigated.

The mechanical strengths of PMMA-based cements were sufficient for tibia reconstruction at CMC contents lower than 4% (≤3%). The concentrations of released cisplatin (12.1% and 16.6% from PMMA with 3% and 4% CMC, respectively) were sufficient for killing of osteosarcoma cells, and the fraction of dead cells increased to 91.3% within 7 days. Functionalized xenogeneic granules released 29.5% of cisplatin, but synthetic CaP granules only released 1.4% of cisplatin over 28 days. The immobilized and released cisplatin retained its anti-cancer efficacy and showed dose-dependent cytostatic effects on the viability of metastatic bone tumor cells.

Bone substitutes can be rendered therapeutically active for anticancer efficacy by functionalization with cisplatin. As such, our data suggest that multi-functional PMMA-based cements and cisplatin-loaded granules represent viable treatment options for filling bone defects after bone tumor resection.

Results in patients undergoing total hip arthroplasty (THA) for femoral head osteonecrosis (ON) when compared with primary osteoarthritis (OA) are controversial. Different factors like age, THA type or surgical technique may affect outcome. We hypothesized that patients with ON had an increased revision rate compared with OA. We analysed clinical outcome, estimated the survival rate for revision surgery, and their possible risk factors, in two groups of patients.

In this retrospective cohort analysis of our prospective database, we assessed 2464 primary THAs implanted between 1989 and 2017. Patients with OA were included in group 1, 2090 hips; and patients with ON in group 2, 374 hips. In group 2 there were more men (p<0.001), patients younger than 60 years old (p<0.001) and with greater physical activity (p<0.001). Patients with lumbar OA (p<0.001) and a radiological acetabular shape type B according to Dorr (p<0.001) were more frequent in group 1. Clinical outcome was assessed according to the Harris Hip Score and radiological analysis included postoperative acetabular and femoral component position and hip reconstruction. Kaplan-Meier survivorship analysis was used to estimate the cumulative probability of not having revision surgery for different reasons. Univariate and multivariate Cox regression models were used to assess risk factors for revision surgery.

Clinical improvement was better in the ON at all intervals. There were 90 hips revised, 68 due to loosening or wear, 52 (2.5%) in group 1, and 16 (4.3%) in group 2. Overall, the survival rate for revision surgery for any cause at 22 years was 88.0 % (95% CI, 82-94) in group 1 and 84.1% (95% CI, 69 – 99) in group 2 (p=0.019). Multivariate regression analysis showed that hips with conventional polyethylene (PE), compared with highly-cross linked PEs or ceramic-on-ceramic bearings, (p=0.01, Hazard Ratio (HR): 2.12, 95% CI 1.15-3.92), and cups outside the Lewinnek´s safe zone had a higher risk for revision surgery (p<0.001, HR: 2.57, 95% CI 1.69-3.91).

Modern highly-cross linked PEs and ceramic-on-ceramic bearings use, and a proper surgical technique improved revision rate in patients undergoing THA due to ON compared with OA.

Herein we address, hyaline cartilage regeneration issue by engineering a synthetic biocompatible hydrogel scaffold capable to promote chondrogenic differentiation. In this study, the chemically crosslinked hydrogels consisting of synthetic peptides that have the collagen-like sequence Cys-Gly-(Pro-Lys-Gly)4 (Pro-Hyp-Gly)4 (Asp-Hyp-Gly)4- conjugated with RGD sequence (CLP-RGD) and crosslinked hydrogels of type I collagen (CA) were used. For cartilage formation, we used human skeletal muscle-derived stem/progenitor cells (hMDSPCs) set for differentiation towards a chondrogenic lineage by BMP-7 and TGF-ß3 growth factors.

Initially 150, 100 and 75 ng of BMP-7and TGF-ß3 growth factors were inserted in each scaffold and amount of growth factors diffusing out of the scaffolds was observed by ELISA assays. In vitro experiments were performed by seeding hMDSPCs onto hydrogels loaded with growth factors (75ng/scaffold) and cultured for 28 days. Cartilage formation was monitored by ELISA and RT-PCR assays. All experiments were performed in triplicates or quadruplicates.

Growth factors incorporation strategy allowed a sustained release of TGF-ß3 growth factor, 6.00.3% of the initially loaded amount diffused out after 4 h and 2.70.5% already at the second time point (24h) from CA and CLP-RGD substrates. For the BMP-7 growth factor, 13.12.3% and 15.751.6% of the initially loaded amount diffused out after 4 h, 1.70.2% and 2.450.3% at the second time point (24 h) from CA and CLP-RGD respectively. In vitro experiments shown that scaffolds with immobilized growth factors resulted in higher collagen type II accumulation when compared to the scaffolds alone. The gene expression on CLP-RGD hydrogels with growth factors has shown lower collagen type I expression and higher aggrecan expression compared to day 0. However, we also report increased collagen X gene expression on CA hydrogels (with growth factors).

Our results support the potential of the strategy of combining hydrogels functionalized with differentiation factors toward improving cartilage repair.

There remains much debate regarding the optimal method for surgical management of patients with long head of biceps pathology. The aim of this study was to compare the outcomes of tenotomy versus tenodesis.

This systematic review and meta-analysis was registered on PROSPERO (ref: CRD42020198658). Electronic databases searched included EMBASE, Medline, PsycINFO, and Cochrane Library. Randomized controlled trials (RCTs) comparing tenotomy versus tenodesis were included. Risk of bias within studies was assessed using the Cochrane risk of bias v2.0 tool and the Jadad score. The primary outcome included patient reported functional outcome measures pooled using standardized mean difference (SMD) and a random effects model. Secondary outcome measures included pain (visual analogue scale VAS), rate of Popeye deformity, and operative time.

860 patients from 11 RCTs (426 tenotomy vs 434 tenodesis) were included in the meta-analysis. Pooled analysis of all PROMs data demonstrated comparable outcomes between tenotomy vs tenodesis (SMD 0.14, 95% CI −0.04 to 0.32; p=0.13). Sensitivity analysis comparing RCTs involving patients with and without an intact rotator cuff did not change the primary outcome. There was no significant difference for pain (VAS). Tenodesis resulted in a lower rate of Popeye deformity (OR 0.29, 95% CI 0.19 to 0.45, p < 0.00001). Tenotomy demonstrated a shorter operative time (MD 15.21, 95% CI 1.06 to 29.36, p < 0.00001).

Aside from a lower rate of cosmetic deformity, tenodesis yielded no measurable significant benefit to tenotomy for addressing pathology in the long head of biceps. A large multi-centre clinical effectiveness randomised controlled trial is needed to provide clarity in this area.

Silk fibroin (SF) has been used as a scaffold for cartilage tissue engineering. Different silkworms strain produced different protein. Also, molecular weight of SF depends on extraction method. We hypothesised that strain of silkworm and method of SF extraction would effect biological properties of SF scaffold. Therefore, cell viability and chondrogenic gene expression of human chondrogenic progenitor cells (HCPCs) treated with SF from 10 silkworm strains and two common SF extraction methods were investigate in this study.

Twenty g of 10 strains silk cocoons were separately degummed in 0.02M Na2CO3 solution and dissolved in 100๐C for 30 minutes. Half of them were then dissolved in CaCl2/Ethanol/H2O [1:2:8 molar ratio] at 70±5๐C (method 1) and other half was dissolved in 46% w/v CaCl2 at 105±5๐C (method 2) for 4 hours. HCPCs were cultured in SF added cultured medial according to strain and extraction method. Cell viability at day 1, 3, and 7, were determined. Expression of collagen I, collagen II, and aggrecan at day 7 and 14, was studied. All experiment were done in triplicated samples.

Generally, method 1 SF extraction showed higher cell viability in all strains. Cell viability from Nanglai Saraburi, Laung Saraburi and Nangtui strains were higher than those without SF in every time point while Wanasawan and J108 had higher viability at day 1 and decreased by time. Expression in collagen 1, collagen 2 and aggrecan in method 1 are higher at day 7 and day 14. Collagen 1 expression was highest in Nangnoi Srisaket, followed by Laung Saraburi and Nanglai Saraburi in day 7. Nangnoi Srisaket also had highest expression at day 14, followed by Nanglai Saraburi and Laung Saraburi respectively. Nangseaw had highest collagen 2 expression, follow by Laung Saraburi and Nangnoi Srisaket respectively. Higher aggrecan gene expression of Tubtimsiam, Wanasawan, UB 1 and Nangnoi Srisaket was observed at day 7 and increased expression of all strains at day 14.

SF extraction using CaCl2/Ethanol/H2O offered better cell viability and chondrogenic expression. Nangseaw, Laung Saraburi and Nangnoi Srisaket strains expressed more chondrogenic phenotype.

Dual mobility (DM) total hip replacements (THRs) were introduced to reduce dislocation risk, which is the most common cause of early revision. Although DM THRs have shown good overall survivorship and low dislocation rates, the mechanisms which describe how these bearings function in-vivo are not fully understood. Therefore, the study aim was to comprehensively assess retrieved DM polyethylene liners for signs of damage using visual inspection and semi-quantitative geometric assessment methods.

Retrieved DM liners (n=18) were visually inspected for the presence of surface damage, whereby the internal and external surfaces were independently assigned a score of one (present) or zero (not present) for seven damage modes. The severity of damage was not assessed. The material composition of embedded debris was characterised using energy-dispersive x-ray analysis (EDX). Additionally, each liner was geometrically assessed for signs of wear/deformation [1].

Scratching and pitting were the most common damage modes on either surface. Additionally, burnishing was observed on 50% of the internal surfaces and embedded debris was identified on 67% of the external surfaces. EDX analysis of the debris identified several materials including titanium, cobalt-chrome, iron, and tantalum. Geometric analysis demonstrated highly variable damage patterns across the liners.

The incidence of burnishing was three times greater for the internal surfaces, suggesting that this acts as the primary articulation site. The external surfaces sustained more observable damage as evidenced by a higher incidence of embedded debris, abrasion, delamination, and deformation. In conjunction with the highly variable damage patterns observed, these results suggest that DM kinematics are complex and may be influenced by several factors (e.g., soft tissue fibrosis, patient activities) and thus further investigation is warranted.

The primary purpose of this longitudinal study was to examine the impact of physical and mental well-being on a successful return to work after cartilage or ligament knee injury. A secondary purpose was to examine the effectiveness of our program regarding ordering imaging (plain X-rays, US, MRI, CT scan), and the impact that costly investigations made in clinical management.

Workers who had sustained a work-related knee injury and were assessed at the lower extremity specialty clinic of our hospital program were followed up until they were discharged. All patients completed the numeric pain rating scale (NPRS), the Lower Extremity Functional Scale (LEFS), and the Hospital Anxiety and Depression Scale (HADS) on the initial assessment and at final follow-up.

We included 30 patients, mean age, 50(9), 11(37%) females, 19(63%) males. The most common mechanisms of injury were twisting (13, 45%) and falls (12, 41%). The knee injuries included 10 anterior collateral ligament (ACL), 3 posterior collateral ligament (PCL), 19 medical and lateral ligament injuries, and 22 meniscus injuries with some injuries overlapping. Ten patients (30%) underwent surgery (8 meniscectomy, two ligamentous repairs).

Patients showed improvement in pain scores (p<0.0001) and the LEFS scores (p=0.004). Seventeen patients (57%) returned to full-time work and 11 (37%) were not working at the time of discharge with one patient performing part-time work, and one on re-training. Higher levels of pre (p=0.02) and post-treatment (p=0.03) depression and post-treatment anxiety (p=0.02) had a negative impact on a successful return to work. Most clients had proper investigations ordered by their family physicians in the community (24 plain x-rays, 11 US, and 21 MRI). Our team ordered only 6 plain x-rays and 6 new MRI.

We found significant improvement in pain and disability in injured workers who received an expedited multidisciplinary care. Anxiety and depression were the most important predictors of poorer recovery and a less successful work status. The judicious use of costly imaging is expected to reduce the overall health care cost of an injury, while providing new important information such as adding a new diagnosis or changing the management.

Our study seeks to determine whether characteristics of radiographs taken post-reduction of a forearm fracture can indicate future risk of refracture or loss of reduction. We hypothesize that reducing forearm fractures too precisely may be counterproductive and provide less benefit than reductions left slightly offset prior to cast immobilization.

We conducted a retrospective review of 1079 pediatric patients treated for forearm fractures between January 2014 and September 2021 in a 327 bed regional medical center. Percent fracture displacement, location, orientation, comminution, fracture line visibility and angle of angulation were determined by AP and lateral radiographs. Percent fracture displacement was derived by: (Displacement of Bone Shafts / Diameter) x 100% = %Fracture Displacement.

Patients treated with closed reduction were reduced from a mean displacement of 29.26±36.18% at an angulation of 22.67±16.57 degrees to 7.88±9.07% displacement and 3.89±6.68 degrees angulation post-reduction. Patients developing complications including a loss of reduction or refracture were found to have post-operative radiographs with a lower percent displacement (0.50±1.12) than those not developing complications (8.65±9.21)(p=0.0580). Post-reduction angulation (p=1.000), average reduction in angulation (p=1.000) and average reduction in displacement percent(p=0.2102) were not significantly associated with development of complications.

Percent displacement of radial shafts was seen to be the most important metric to monitor in post-operative radiographs for patients undergoing closed reduction of a forearm fracture. We theorize a slight displacement provides greater surface area for osteoblastic expansion and callus formation leading to a decreased risk of refracture or loss of reduction. While our sample size precludes our ability to measure the ideal amount of post-reduction displacement for optimal healing, our results demonstrate that some degree of shaft displacement is required for optimal healing conditions.

This study was conducted to investigate the characteristics, complications, radiologic features and clinical course of patients undergoing reduction of forearm fractures in order to better inform patient prognosis and postoperative management.

We conducted a retrospective cohort study of 1079 pediatric patients treated for forearm fractures between January 2014 and September 2021 in a 327 bed regional medical center. A preoperative radiological assessment and chart review was performed. Percent fracture displacement, location, orientation, comonution, fracture line visibility and angle of angulation were determined by AP and lateral radiographs. Percent fracture displacement was derived by: (Displacement of Bone Shafts / Diameter) x 100% = %Fracture Displacement. Angle of angulation and percent fracture displacement were calculated by averaging AP and lateral radiograph measurements.

80 cases, averaging 13.5±8.3 years, were identified as having a complete fracture of the radius and/or ulna with 69 receiving closed reduction and 11 receiving fixation via an intramedullary device or percutaneous pinning. Eight patients (10%) experienced complications with four resulting in a refracture and four resulting in significant loss of reduction (LOR) without refracture. Fractures in the proximal ⅔s of the radius were associated with a significant increase in complications compared to fractures in the distal ⅓ of the radius (31.6% vs 3.4%) (P=.000428). Likewise, a higher percent fracture displacement was associated with a decreased risk of complications (28.7% vs 5.9% displacement)(P=0.0403). No elevated risk of complications was found based on fracture orientation, angulation, fracture line visibility, forearm bone(s) fractured, sex, age or arm affected.

Our result highlights radius fracture location and percent fracture displacement as markers with prognostic value following forearm fracture. These measurements are simply calculated via pre-reduction radiographs, providing an efficient method of informing risk of complications following forearm fracture.

The efficacy of saline irrigation for the treatment of periprosthetic infection (PJI) is limited in the presence of infected implants. This study evaluated the efficacy of vancomycin/tobramycin-doped polyvinyl alcohol (PVA)/ceramic composites (PVA-VAN/TOB-P) after saline irrigation in a mouse pouch infection model.

3D printed porous titanium (Ti) cylinders (400, 700 and 100 µm in pore size) were implanted into mice pouches, then inoculated with S. aureus at the amounts of 1X10³ CFU and 1X10⁶ CFU per pouch, respectively. Mice were randomized into 4 groups (n=6 for each group): (1) no bacteria; (2) bacteria without saline wash; 3) saline wash only, and (4) saline wash+PVA-VAN/TOB-P. After seven days, pouches were washed out alone or with additional injection of 0.2 ml of PVA-VAN/TOB-P. Mice were sacrificed 14 days after pouch wash. Bacteria cultures of collected Ti cylinders and washout fluid and histology of pouch tissues were performed.

The low-grade infection (1X10³ CFU) was more significant in 400 µm Ti cylinders than that in Ti cylinders with larger pore sizes (700 and 1000 µm (p<0.05). A similar pattern of high-grade infection (1X10⁶ CFU) was observed (p<0.05). For the end wash, the bacteria burden (0.49±0.02) in saline wash group was completely eradicated by the addition of PVA-VAN/TOB-P (0.005±0.001, p<0.05).

We noticed that 400 µm Ti cylinders have the highest risk of implant infection. Our data supported that the effect of saline irrigation was very limited in the presence of contaminated porous Ti cylinders. PVA-VAN/TOB-P was biodegradable, biocompatible, and was effective in eradicating bacteria retention after saline irrigation in a mouse model of low grade and high-grade infection. We believe that PVA-VAN/TOB-P represents an alternative to reduce the risk of PJI by providing a sustained local delivery of antibiotics.

In the field of hand surgery, physicians are working to improve patient satisfaction by offering several minor procedures in the physician's office via the WALANT method. We seek to investigate the degree of patient satisfaction, out of pocket cost, convenience and comfort experienced with in-office hand procedures.

A ten question survey consisting of a ten-point Likert scale of agreement and questions asking for a numerical answer was administered via phone call to 33 patients treated with minor hand operations in the office setting in the United States.

There were 18 male and 15 female respondents with an average age of 65.59±12.64 years. Respondents underwent procedures including trigger finger release (18), needle aponeurotomy (7), and other minor hand operations. Survey responses indicated strong agreement with questions 1-3 and 6–8, with responses averaging 9.60±0.23 in these positive metrics. Questions 4 and 5, which asked whether the surgery and recovery period were painful, respectively, averaged 2.65±0.49, indicating a mild level of disagreement that either was “painful”. Additionally, most patients responded that they did not take time off work (12) or are not currently employed (11). Other respondents (3) reported taking between one to five days off work post-operatively. 27 respondents also reported an out of pocket cost averaging $382±$976, depending on insurance coverage.

Patients reported a small degree of pain in the operative and post-operative period, a high degree of comfort and convenience and a high degree of satisfaction. Likewise, the patient-reported out of pocket cost was far lower than comparable surgical costs in alternate settings. These results support the use of in-office procedures for minor hand surgeries from a patient perspective and indicate a nearly universal intent to repeat any future hand operations in the office setting.

Staphylococcus aureus (SA), the predominant pathogen in human osteomyelitis, is known to persist by forming intracellular reservoirs, including in bone cells (Schwarz et al., 2019, Yang et al., 2018, Krauss et al., 2019, Gao et al., 2020, Bosse et al., 2005), promoting decreased antibiotic susceptibility. However, there are no evidence-based treatment guidelines for intracellular SA infections in osteomyelitis. We sought to address this by systematically reviewing the literature and, testing a selection of antibiotic treatments in a clinically relevant in vitro assay.

We conducted a systematic review of the literature to determine the current evidence for the efficacy of antibiotics against intracellular SA infections relevant to osteomyelitis. For the antibiotics identified as potentially useful, we determined their minimal inhibitory concentration (MIC) against 11 clinical osteomyelitis SA- isolates. We selected those for further testing reported able to reach a higher concentration in the bone than the identified MIC against the majority of strains. Thus, rifampicin, oxacillin, linezolid, levofloxacin, oritavancin and doxycycline were tested in human SaOS-2-osteocyte infection models (Gunn et al., 2021) of acute (1d) or chronic (14d) infection to clear intracellular SA. Antibiotics were tested at 1x/4x/10x the MIC for the duration of 1d or 7d in each model.

A systematic review found that osteoblasts and macrophages have mostly been used to test immediate short-term activity against intracellular SA, with a high variability in methodology. However, some extant evidence supports that rifampicin, oritravancin, linezolid, moxifloxacin and oxacillin may be effective intracellular treatments. While studies are ongoing, in vitro testing in a clinically relevant model suggests that rifampicin, oxacillin and doxycycline could be effectively used to treat osteomyelitic intracellular SA infections. Importantly, these have lower MICs against multiple clinical isolates than their respective clinically-achievable bone concentrations.

The combined approach of a systematic review and disease-relevant in vitro screening will potentially inform as to the best approach for treating osteomyelitis where intracellular SA infection is confirmed or suspected.

Tibial shaft fractures require surgical stabilization preferably by intramedullary nailing. However, patients often report functional limitations even years after the injury. This study investigates the influence of the surgical approach (transpatellar vs. parapatellar) on gait performance and patient reported outcome six months after surgery.

Twenty-two patients with tibial shaft fractures treated by intramedullary nailing through a transpatellar approach (TP: n=15, age 41±15, BMI 24±3) or a parapatellar approach (PP: n=7, age 34±15, BMI 23±2) and healthy, matched controls (n=22, age 39±13, BMI 24±2) were assessed by instrumented motion analysis six months after intramedullary nailing. Short musculoskeletal function assessment questionnaire (SMFA) as well as kinematic and kinetic gait data were collected during level walking. Comparisons among approach methods and control group were performed by analysis of variance and Mann-Whitney test.

Six months after surgery, knee kinetics in both groups differed significantly compared to controls (p <.04). The approach method affected gait speed (TP: p = .002; PP: p = .08) and knee kinematics in the early stance phase (TP: p = .011; PP: p = .082), with the parapatellar approach showing a more favorable outcome. However, the difference between patient groups was not significant for any of the assessed gait parameters (p > .2). Also, no differences could be found in the bother index (BI) or function index (FI) of SMFA between surgical approach methods (BI: TP: Mdn = 7.2, PP: Mdn = 9.4; FI: TP: Mdn = 10.3, PP: Mdn = 9.2, p > .7).

Our study demonstrates, that six months after surgery for tibial shaft fractures functional limitations remain. These limitations appear not to be different for either a trans- or a parapatellar approach for the insertion of the intramedullary nail. The findings of this study are limited by the relatively short follow up time period and small number of patients. Future studies should investigate the source of the functional limitation after intramedullary nailing of tibial shaft fractures.

To test and evaluate the effectiveness of local injection of autologous fat-derived mesenchymal stem cells (MSCs) into fracture site to prevent non-union in a clinically relevant model.

5 male Wistar rats underwent the same surgical procedure of inducing non-union. A mid-shaft tibial osteotomy was made with 1mm non-critical gap. Periosteum was stripped around the two fracture ends. Then, the fracture was fixed by ante-grade intramedullary nail. The non-critical gap was maintained by a spacer with minimal effect on the healing surface area. At the same surgical time, subcutaneous fat was collected from the ipsilateral inguinal region and stem cells were isolated and cultured in vitro. Within three weeks postoperatively, the number of expanded stem cells reached 5×10⁶ and were injected into the fracture site. Healing was followed up for 8 weeks and the quality was measured by serial x-rays, microCT, mechanical testing and histologically. Quality of healing was compared with that of previously published allogenic, xenogeneic MSCs and Purified Buffered Saline (PBS) controls.

All the five fractures united fully after 8 weeks. There was a progressive increase in the callus radiopacity during the eight-week duration, the average radiopacity in the autologous fat-MSC injected group was significantly higher than that of the allogeneic MSCs, xenogeneic MSCs and the control group, P < 0.0001 for treatment, time after injection, and treatment-time interaction (two-way repeated measure ANOVA). MicroCT, mechanical testing and histology confirmed radiological findings.

The autologous fat-MSCs are effective in prevention of atrophic non-union by stimulation of the healing process leading to a solid union. The quality and speed of repair are higher than those of the other types of cell transplantation tested.

Re-rupture rates after rotator cuff repair remain high because of inadequate biological healing at the tendon-bone interface. Single-growth factor therapies to augment healing at the enthesis have so far yielded inconsistent results. An emerging approach is to combine multiple growth factors over a spatiotemporal distribution that mimics normal healing. We propose a novel combination treatment of insulin-like growth factor 1 (IGF-1), transforming growth factor β1 (TGF-β1) and parathyroid hormone (PTH) incorporated into a controlled-release tyraminated poly-vinyl-alcohol hydrogel to improve healing after rotator cuff repair. We aimed to evaluate this growth factor treatment in a rat chronic rotator cuff tear model.

A total of 30 male Sprague-Dawley rats underwent unilateral supraspinatus tenotomy. Delayed rotator cuff repairs were then performed after 3 weeks, to allow tendon degeneration that resembles the human clinical scenario. Animals were randomly assigned to: [1] a control group with repair alone; or [2] a treatment group in which the hydrogel was applied at the repair site. All animals were euthanized 12 weeks after rotator cuff surgery and the explanted shoulders were analyzed for biomechanical strength and histological quality of healing at the repair site.

In the treatment group had significantly higher stress at failure (73% improvement, P=0.003) and Young's modulus (56% improvement, P=0.028) compared to the control group. Histological assessment revealed improved healing with significantly higher overall histological scores (10.1 of 15 vs 6.55 of 15, P=0.032), and lower inflammation and vascularity.

This novel combination growth factor treatment improved the quality of healing and strength of the repaired enthesis in a chronic rotator cuff tear model. Further optimization and tailoring of the growth factors hydrogel is required prior to consideration for clinical use in the treatment of rotator cuff tears. This novel treatment approach holds promise for improving biological healing of this clinically challenging problem.

The lateral wall thickness (LWT) in trochanteric femoral fractures is a known predictive factor for postoperative fracture stability. Currently, the AO/OTA classification uses a patient non-specific measure to assess the absolute LWT (aLWT) and distinguish stable A1.3 from unstable A2.1 fractures based on a threshold of 20.5 mm. This approach potentially results in interpatient deviations due to different bone morphologies and consequently variations in fracture stability. Therefore, the aim of this study was to explore whether a patient-specific measure for assessment of the relative LWT (rLWT) results in a more precise threshold for prediction of unstable fractures.

Part 1 of the study evaluated 146 pelvic radiographs to assess left-right symmetry with regard to caput-collum-angle (CCD) and total trochanteric thickness (TTT), and used the results to establish the rLWT measurement technique. Part 2 reevaluated 202 patients from a previous study cohort to analyze their rLWT versus aLWT for optimization purposes.

Findings in Part 1 demonstrated a bilateral symmetry of the femur regarding both CCD and TTT (p ≥ 0.827) allowing to mirror bone's morphology and geometry from the contralateral intact to the fractured femur. Outcomes in Part 2 resulted in an increased accuracy for the new determined rLWT threshold (50.5%) versus the standard 20.5 mm aLWT threshold, with sensitivity of 83.7% versus 82.7% and specificity 81.3% versus 77.8%, respectively.

The novel patient-specific rLWT measure can be based on the contralateral femur anatomy and is a more accurate predictor of a secondary lateral wall fracture in comparison to the conventional aLWT. This study established the threshold of 50.5% rLWT as a reference value for prediction of fracture stability and selection of an appropriate implant for fixation of trochanteric femoral fractures.

To analyse bone stresses in humerus-megaprosthesis construct in response to axial loading under varying implant lengths in proximal humeral replacement following tumour excision.

CT scans of 10 cadaveric humeri were processed in 3D Slicer to obtain three-dimensional (3D) models of the cortical and cancellous bone. Megaprostheses of varying body lengths (L) were modelled in FreeCAD to obtain the 3D geometry. Four FE models: group A consisting of intact bone; groups B (L=40mm), C (L=100mm) and D (L=120mm) comprising of humerus-megaprosthesis constructs were created. Isotropic linear elastic behaviour was assigned for all materials. A tensile load of 200N was applied to the elbow joint surface with the glenohumeral joint fixed with fully bonded contact interfaces. Static analysis was performed in Abaqus. The bone was divided at every 5% bone length beginning distally. Statistical analysis was performed on maximum von Mises stresses in cortical and cancellous bone across each slice using one-way ANOVA (0-45% bone length) and paired t-tests (45-70% bone length). To quantify extent of stress shielding, average percentage change in stress from intact bone was also computed.

Maximum stress was seen to occur distally and anteriorly above the coronoid fossa. Results indicated statistically significant differences between intact state and shorter megaprostheses relative to longer megaprostheses and proximally between intact and implanted bones. Varying levels of stress shielding were recorded across multiple slices for all megaprosthesis lengths. The degree of stress shielding increased with implant lengthening being 2-4 times in C and D compared to B.

Axial loading of the humerus can occur with direct loading on outstretched upper limbs or indirectly through the elbow. Resultant stress shielding effect predicted in longer megaprosthesis models may become clinically relevant in repetitive axial loading during activities of daily living. It is recommended to use shorter megaprosthesis to prevent failure.

The e-scooter trial was part of a wider initiative from the Department for Transport in response to COVID pandemic. New emergency legislation was introduced in 2020 to make e-scooters legal in the UK for the first time. This scheme was launched in our county from September 2020. The aim of this case series was to identify the types of Orthopedic injuries resultant from electric scooter transport that presented to our District General Hospital over a 16-month period between September 2020 and December 2021.

This study involved retrospective collection of data from electronic hospital records. Data on demographics, laterality, date of injury, type of injury, treatment, HDU/ITU admissions, mortality, and operating time were collected to characterize the types of e-scooter-related injuries and to investigate the frequency of such injuries over the duration of our search.

A total of 79 orthopedic patients identified with electric scooter injuries between September 2020 and December 2021. 78.5% were males and the mean age was 30.1 years. Summer months accounted for most of the injuries. 17 patients required inpatient care. 23 patients required surgical intervention and a total of 29 surgeries were performed in our hospital. This accounted for a total surgical time of 2088 minutes. One patient admitted with shaft of femur fracture developed pulmonary embolism after the definitive operation and died in HDU.

Electric scooters provide a space efficient, affordable, environmentally friendly mode of transportation which reduce the urban congestion and parking issues. This study demonstrates an increasing frequency of significant orthopedic injury associated with e-scooter use treated at our centre over the course of 16 months. This small series underlines an important problem given that this increase has occurred after the start of the electric scooter trial. Legalization might result in further increase in the incidence of injury.

This study aims to compare the biomechanical properties of the “Double Lasso-Loop” suture anchor (DLSA) technique with the commonly performed interference screw (IS) technique in an ex vivo ovine model.

Fourteen fresh sheep shoulder specimens were used in this study. Dissection was performed leaving only the biceps muscle attached to the humerus and proximal radius before sharply incised to simulate long head of biceps tendon (LHBT) tear. Repair of the LHBT tear was performed on all specimens using either DSLA or IS technique. Cyclical loading of 500 cycles followed by load to failure was performed on all specimens. Tendon displacement due to the cyclical loading at every 100 cycles as well as the maximum load at failure were recorded and analysed. Stiffness was also calculated from the load displacement graph during load to failure testing.

No statistically significant difference in tendon displacement was observed from 200 to 500 cycles. Statistically significant higher stiffness was observed in IS when compared with DSLA (P = .005). Similarly, IS demonstrated significantly higher ultimate failure load as compared with DSLA (P = .001). Modes of failure observed for DSLA was mostly due to suture failure (7/8) and anchor pull-out (1/8) while IS resulted in mostly LHBT (4/6) or biceps (2/6) tears. DSLA failure load were compared with previous studies and similar results were noted.

After cyclical loading, tendon displacement in DLSA technique was not significantly different from IS technique. Despite the higher failure loads associated with IS techniques in the present study, absolute peak load characteristics of DLSA were similar to previous studies. Hence, DLSA technique can be considered as a suitable alternative to IS fixation for biceps tenodesis.

Bone defects require implantable graft substitutes, especially porous and biodegradable biomaterial for tissue regeneration. The aim of this study was to fabricate and assess a 3D-printed biodegradable hydroxyapatite/calcium carbonate scaffold for bone regeneration.

Depletion of Scleraxis-lineage (ScxLin) cells in adult tendon recapitulates age-related decrements in cell density, ECM organization and composition. However, depletion of ScxLin cells improves tendon healing, relative to age-matched wildtype mice, while aging impairs healing. Therefore, we examined whether ScxLin depletion and aging result in comparable shifts in the tendon cell environment and defined the intrinsic programmatic shifts that occur with natural aging, to define the key regulators of age-related healing deficits.

ScxLin cells were depleted in 3M-old Scx-Cre+; Rosa-DTRF/+ mice via diphtheria toxin injections into the hindpaw. Rosa-DTRF/+ mice were used as wildtype (WT) controls. Tendons were harvested from 6M-old ScxLin depleted and WT mice, and 21-month-old (21M) C57Bl/6 mice (aged). FDL tendons (n=6) were harvested for single-cell RNAseq, pooled, collagenase digested, and sorted for single cell capture. Data was processed using Cell Ranger and then aligned to the annotated mouse genome (mm10). Filtering, unsupervised cell clustering, and differential gene expression (DEG) analysis were performed using Seurat.

Following integration and sub-clustering of the tenocyte populations, five distinct subpopulations were observed. In both ScxLin depletion and aging, ‘ECM synthesizers’ and ‘ECM organizers’ populations were lost, consistent with disruptions in tissue homeostasis and altered ECM composition. However, in ScxLin depleted mice retention of a ‘specialized ECM remodeler’ population was observed, while aging tendon cells demonstrated inflammatory skewing with retention of a ‘pro-inflammatory tenocyte population’. In addition, enrichment of genes associated with protein misfolding clearance were observed in aged tenocytes. Finally, a similar inflammatory skewing was observed in aged tendon-resident macrophages, with this skewing not observed in ScxLin depleted tendons.

These data suggest that loss of ‘ECM synthesizer’ populations underpins disruptions in tendon homeostasis. However, retention of ‘specialized remodelers’ promotes enhanced healing (ScxLin depletion), while inflammatory skewing may drive the impaired healing response in aged tendons.

3D spheroid culture is a bridge between standard 2D cell culture and in vivo research which mimics the physiological microenvironment in scaffold-free conditions. Here, this 3D technique is being investigated as a potential method for engineering bone tissue in vitro. However, spheroid culture can exhibit limitations, such as necrotic core formation due to the restricted access of oxygen and nutrients. It is therefore important to determine if spheroids without a sizeable necrotic core can be produced. This study aims to understand necrotic core formation and cell viability in 3D bone cell spheroids using different seeding densities and media formulations.

Differentiated rat osteoblasts (dRObs) were seeded in three different seeding densities (1×10⁴, 5×10⁴, 1×10 cells) in 96 well U-bottom cell-repellent plates and in three different media i.e., Growth medium (GM), Mineralisation medium 1 (MM1) and MM2. Spheroids were analysed from day 1 to 28 (N=3, n=2). Cell count and viability was assessed by trypan blue method. One way ANOVA and post-hoc Tukey test was performed to compare cell viability among different media and seeding densities. Histological spheroid sections were stained with hematoxylin and eosin (H&E) to identify any visible necrotic core.

Cell number increased from day 1 to 28 in all three seeding densities with a notable decrease in cell viability. 1×10⁴ cells proliferated faster than 5×10⁴ and 1×10⁵ cells and had proportionately similar cell death. The necrotic core area was relatively equivalent between all cell seeding densities. The larger the spheroid size, the larger is the size of the necrotic core.

This study has demonstrated that 3D spheroids can be formed from dRobs at a variety of seeding densities with no marked difference in necrotic core formation. Future studies will focus on utilising the bone cell spheroids for engineering scalable scaffold-free bone tissue constructs.