Device-associated bacterial infections are a major and costly clinical challenge. This project aimed to develop a smart new biomaterial for implants that helps to protect against infection and inflammation, promote bone growth, and is biodegradable. Gallium (Ga) doped strontium-phosphate was coated on pure Magnesium (Mg) through a chemical conversion process. Mg was distributed in a graduated manner throughout the strontium-phosphate coating GaSrPO4, with a compact structure and a Ga-rich surface. We tested this sample for its biocompatibility, effects on bone remodeling and antibacterial activities including Staphylococcus aureus, S. epidermidis and E. coli - key strains causing infection and early failure of the surgical implantations in orthopaedics and trauma.

Ga was distributed in a gradient way throughout the entire strontium-phosphate coating with a compact structure and a gallium-rich surface. The GaSrPO4 coating protected the underlying Mg from substantial degradation in minimal essential media at physiological conditions over 9 days. The liberated Ga ions from the coatings upon Mg specimens inhibited the growth of bacterial tested. The Ga dopants showed minimal interferences with the SrPO4 based coating, which boosted osteoblasts and undermined osteoclasts in in vitro co-cultures model.

The results evidenced this new material may be further translated to preclinical trial in large animal model and towards clinical trial.

Acknowledgements: Authors are grateful to the financial support from the Australian Research Council through the Linkage Scheme (ARC LP150100343). The authors acknowledge the facilities, and the scientific and technical assistance of the RMIT University and John Curtin School of Medical Research, Australian National University.

To propose a modified approach to measuring femoro-epiphyseal acetabular roof (FEAR) index while still abiding by its definition and biomechanical basis, and to compare the reliabilities of the two methods. To propose a classification for medial sourcil edges.

We retrospectively reviewed a consecutive series of patients treated with periacetabular osteotomy and/or hip arthroscopy. A modified FEAR index was defined. Lateral center-edge angle, Sharp's angle, Tonnis angle on all hips, as well as FEAR index with original and modified approaches were measured. Intra- and inter-observer reliability were calculated as intraclass correlation coefficients (ICC) for FEAR index with both approaches and other alignments. A classification was proposed to categorize medial sourcil edges. ICC for the two approaches across different sourcil groups were also calculated.

After reviewing 411 patients, 49 were finally included. Thirty-two patients (40 hips) were identified as having borderline dysplasia defined by an LCEA of 18 to 25 degrees. Intra-observer ICC for the modified method were good to excellent for borderline hips; poor to excellent for DDH; moderate to excellent for normal hips. As for inter-observer reliability, modified approach outperformed original approach with moderate to good inter-observer reliability (DDH group, ICC=0.636; borderline dysplasia group, ICC=0.813; normal hip group, ICC=0.704). The medial sourcils were classified to 3 groups upon its morphology. Type II(39.0%) and III(43.9%) sourcils were the dominant patterns. The sourcil classification had substantial intra-observer agreement (observer 4, kappa=0.68; observer 1, kappa=0.799) and moderate inter-observer agreement (kappa=0.465). Modified approach to FEAR index possessed greater inter-observer reliability in all medial sourcil patterns.

The modified FEAR index has better intra- and inter-observer reliability compared with the original approach. Type II and III sourcils accounts for the majority to which only the modified approach is applicable.

Aims

This study aimed to explore the diagnostic value of synovial fluid neutrophil extracellular traps (SF-NETs) in periprosthetic joint infection (PJI) diagnosis, and compare it with that of microbial culture, serum ESR and CRP, synovial white blood cell (WBC) count, and polymorphonuclear neutrophil percentage (PMN%).

Knee arthroscopy with debridement is commonly performed to treat osteoarthritis and degenerative meniscal tears in older adults; however robust evidence does not support sustained benefit from this procedure. Current Canadian guidelines advise against its use as first line treatment. Characterizing the use of this low value procedure will facilitate efforts to maximize quality of care, minimize harm and decrease healthcare costs. We sought to understand:

Data were derived from National Ambulatory Care Reporting System (NACRS), the Discharge Abstract Database (DAD) and the National Physician Database for years 2011-12 to 2019-20. The study included all elective knee arthroscopies (CCI codes 1.VG.80.DA,1.VG.80.FY and 1.VG.87.DA) performed in day surgery and acute care settings in 9 provinces and 3 territories of Canada. Quebec was not included in the analysis due to different reporting methods. We set a threshold of 60 years of age at which it would be highly unlikely that a patient would undergo arthroscopy to treat anything other than osteoarthritis or degenerative meniscal tear. Trends at national and provincial levels were analyzed using regression. Costs were estimated separately using the 2020 case mix groups (CMG) and comprehensive ambulatory care classification system (CACS) methodologies. Surgeons were classified by decade of graduation from medical school (1989 and prior, 1990-99, 2000-09 and 2010+) and categorized based on the proportion of their patient population who were above (“high proportion inappropriate”) or below (“low proportion inappropriate”) the overall national proportion of ≥ 60 years of age.

The number of knee arthroscopies decreased by 37% (42,785 in 2011-12 to 27,034 in 2019-20) overall and 39% (11,103 in 2011-12 to 6,772 in 2019-20) in those 60 years and older (p 25% of patients 60 years and older. Fifty four percent of surgeons who graduated prior to 1989 were considered high proportion inappropriate, whereas only 30.1% of surgeons who graduated in 2010 or later were considered high proportion inappropriate (p < 0 .0001).

Knee arthroscopy continues to be a common procedure in patients over 60 despite strong evidence for lack of benefit. Lower rates in this population in some provinces are encouraging for potential opportunity for improvement. Efforts at practice change should be targeted at surgeons in practice the longest. Canada spends over $12,000,000 per year on this procedure, decreasing its use could allow these resources to be directed to other areas of orthopaedics that provide higher value care.

Aims

This study aimed to explore the role of small colony variants (SCVs) of Staphylococcus aureus in intraosseous invasion and colonization in patients with periprosthetic joint infection (PJI).

This retrospective study was to investigate radiographic and clinical outcomes in treatment of hip instability in children and young adults undergoing periacetabular osteotomy (PAO) with or without femoral osteotomy.

19 patients (21 hips) with CP were treated with PAO with or without femoral osteotomy The mean age was 16.2 years old (7 to 28 years). Five patients (5 hips) received PAO, Six patients (7 hips) PAO with femoral derotation osteotomy, Eight patients (9 hips) PAO with varus derotational osteotomy (VDRO). Anteroposterior pelvic radiographs and CT were taken to assess the migration percentage (MP), lateral center-edge angle (LCEA), Sharp angle, femoral neck anteversion, neck-shaft angle. Gross Motor Function Classification System (GMFCS) was assessed pre- and post-surgery. Complications were recorded. The mean follow-up time was 41.2 months (range, 24 to 86 months).

All hips but one were pain free at final visit. The GMFCS improved by one level in 10 of 19 patients. MP improved from a mean of 76.6% to 18.6% at the final follow-up(p<0.001). The mean pre-operative LCEA and Sharp angle were −33.5 ? and 35 ? respectively, improved to 21.5 ? and 11.8 ? at the final follow-up (p < 0.001). There were six patients (7 hips) had re-subluxation at latest follow-up. Nervus cutaneus femoris lateralis was impaired in four patients after surgery. There was no re-dislocation, AVN, or infections in this group.

Satisfactory clinical and radiologic results can be obtained by PAO with or without femoral osteotomy minor complications.

Aims

The value of core decompression (CD) in the treatment of osteonecrosis of the femoral head (ONFH) remains controversial. We conducted a systematic review and meta-analysis to evaluate whether CD combined with other treatments could improve the clinical and radiological outcomes of ONFH patients compared with CD alone.

Aims

LY3023414 is a novel oral phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) dual inhibitor designed for advanced cancers, for which a phase II clinical study was completed in March 2020; however, little is known about its effect on bone modelling/remodelling. In this study, we aimed to explore the function of LY3023414 in bone modelling/remodelling.

Patient-reported outcome measures (PROMs) are being used increasingly in total knee arthroplasty (TKA). We conducted a systematic review aimed at identifying psychometrically sound PROMs by appraising their measurement properties. Studies concerning the development and/or evaluation of the measurement properties of PROMs used in a TKA population were systematically retrieved via PubMed, Web of Science, Embase, and Scopus. Ratings for methodological quality and measurement properties were conducted according to updated COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology. Of the 155 articles on 34 instruments included, nine PROMs met the minimum requirements for psychometric validation and can be recommended to use as measures of TKA outcome: Oxford Knee Score (OKS); OKS–Activity and Participation Questionnaire (OKS-APQ); 12-item short form Knee Injury and Osteoarthritis Outcome (KOOS-12); KOOS Physical function Short form (KOOS-PS); Western Ontario and McMaster Universities Arthritis Index-Total Knee Replacement function short form (WOMAC-TKR); Lower Extremity Functional Scale (LEFS); Forgotten Joint Score (FJS); Patient’s Knee Implant Performance (PKIP); and University of California Los Angeles (UCLA) activity score. The pain and function subscales in WOMAC, as well as the pain, function, and quality of life subscales in KOOS, were validated psychometrically as standalone subscales instead of as whole instruments. However, none of the included PROMs have been validated for all measurement properties. Thus, further studies are still warranted to evaluate those PROMs. Use of the other 25 scales and subscales should be tempered until further studies validate their measurement properties.

Cite this article: Bone Joint Res 2021;10(3):203–217.

Aims

The diagnosis of periprosthetic joint infection (PJI) has always been challenging. Recently, D-dimer has become a promising biomarker in diagnosing PJI. However, there is controversy regarding its diagnostic value. We aim to investigate the diagnostic value of D-dimer in comparison to ESR and CRP.

Osteosarcoma (OS) is the most prevalent bone tumor in children and young adults. Most tumors arise from the metaphysis of the long bones and easily metastasize to the lungs. Current therapeutic strategies of osteosarcoma are routinely surgical resection and chemotherapy, which are limited to the patients suffering from metastatic recurrence. Therefore, to investigate molecular mechanisms that contribute to osteosarcoma progression is very important and may shed light on targeted therapeutic approach to improve the survival of patients with this disease. Several miRNAs have been found expressed differentially in osteosarcoma (OS), In this study, we found that miR-144 significantly suppresses osteosarcoma cell proliferation, migration andinvasion ability in vitro, and inhibited tumor growth and metastasisin vivo. The function and molecular mechanism of miR-144 in Osteosarcoma was further investigated.

Tissue samples from fifty-one osteosarcoma patients were obtained from Shanghai Ninth People's Hospital. The in vitro function of miR-144 in Osteosarcoma was investigated by cell viability assay, wound healing assay, invasion assay, the molecular mechanism was identified by Biotin-coupled miRNA capture, Dual-luciferase reporter assays, etc. the in vivo function of miR-144 in osteosarcoma was confirmed by osteosarcoma animal model and miR-144−/− zebrafish model.

Mechanically, we demonstrated that Ras homolog family member A (RhoA) and its pivotal downstream effector Rho-associated, coiled-coil containing protein kinase 1 (ROCK1) were both identified as direct targets of miR-144. Moreover, the negative co-relation between downregulated miR-144 and upregulated ROCK1/RhoA was verified both in the osteosarcoma cell lines and clinical patients' specimens. Functionally, RhoA with or without ROCK1 co-overexpression resulted a rescue phenotype on the miR-144 inhibited cell growth, migration and invasion abilities, while individual overexpression of ROCK1 had no statistical significance compared with control in miR-144 transfected SAOS2 and U2-OS cells.

This study demonstrates that miR-144 inhibited tumor growth and metastasis in osteosarcoma via dual-suppressing of RhoA and ROCK1, which could be a new therapeutic approach for the treatment ofosteosarcoma.

Osteoarthritis (OA) is a chronic degenerative joint disease with cartilage degeneration, subchondral bone sclerosis, synovial inflammation and osteophyte formation. Sensory nerves play an important role in bone metabolism and in the progression of inflammation. This study explored the effects of capsaicin-induced sensory nerve denervation on OA progression in mice.

This study was approved by the Institutional Animal Care and Use Committee. OA was induced via destabilization of the medial meniscus (DMM). Sensory denervation was induced by subcutaneous injection of capsaicin (90mg/kg) one week prior to DMM. One week after capsaicin injection, sensory denervation in the tibia was confirmed by immunofluorescent staining with calcitonin gene-related peptide (CGRP)-specific antibodies. Four weeks after DMM, micro-CT scans, histological analysis and RT-PCR tests were performed to evaluate OA progression. Statistical analysis was performed using SPSS 13. P values of less than 0.05 were considered statistically significant.

Subcutaneous injection of capsaicin successfully induced tibial sensory denervation (n=3), which aggravated OA by increasing subchondral bone resorption. The Osteoarthritis Research Society International (OARSI) score of the capsaicin+DMM group (n=8) (11.81±2.92) was significantly higher (P=0.003) than the score of the vehicle+DMM group (n=8) (8.31±1.80). The BV/TV of the tibial subchondral bone in the capsaicin+DMM group (n=8) was 55.67%±3.08, which was significantly lower (P < 0 .001) than in the vehicle+DMM group (n=8) (86.22%±1.92). In addition, the level of expression of somatostatin in the capsaicin+DMM group (n=8) was lower than in the vehicle+DMM group (n=8) (P=0.007).

Capsaicin-induced sensory denervation increased tibial subchondral bone resorption, reduced the expression of somatostatin and eventually exacerbated the existing cartilage degeneration in mice. Despite capsaicin is often used clinically to relieve OA pain, its safety is still controversial according to the OARSI guidelines for the non-surgical management of knee osteoarthritis. The findings of our study suggest that application of capsaicin, although effective in relieving pain, may accelerate the progression of existing OA.

INTRODUCTION

The magnitude of principal strain is indicative of the risks of femoral fracture,^1,2 while changes in femoral strain energy density (SED) after total hip arthroplasty (THA) have been associated with bone remodeling stimulus.³ Although previous modeling studies have evaluated femoral strains in the intact and implanted femur under walking loads through successfully predicting physiological hip contact force and femoral muscle forces,^1,2,3 strains during ‘high load’ activities of daily living have not typically been evaluated. Hence, the objective of this study was to compare femoral strain between the intact and the THA implanted femur under peak loads during simulated walking, stair descent, and stumbling.

Objectives

Different criteria for assessing the reduction quality of trochanteric fractures have been reported. The Baumgaertner reduction quality criteria (BRQC) are relatively common and the Chang reduction quality criteria (CRQC) are relatively new. The objectives of the current study were to compare the reliability of the BRQC and CRQC in predicting mechanical complications and to investigate the clinical implications of the CRQC.

Introduction

Reverse Shoulder Arthroplasty (RSA) is recognized to be an effective solution for rotator cuff deficient arthritic shoulders, but there are still concerns about impingement and range of motion (ROM). Several RSA biomechanical studies have shown that humeral lateralization can increase ROM in planar motions (e.g. abduction). However, there is still a debate whether humeral lateralization should be achieved with a larger sphere diameter or by lateralizing the center of rotation (COR). The latter has shown to decrease the deltoid moment arm and increase shear forces, where the former may pose challenges in implanting the device in small patients. The aim of this study was to evaluate how humeral lateralization achieved by varying COR lateral offset and glenosphere diameter in a reverse implant can affect impingement during activities of daily living (ADLs).

We investigated the preliminary results of femoral head necrosis treated by modified femoral neck osteotomy through surgical hip dislocation in young adults.

33 patients with femoral head osteonecrosis received modified femoral neck osteotomy through surgical hip dislocation from March 2015. 14 patients who had minimal 12 months of follow-up were reviewed radiographically and clinically (mean follow-up:16 months, 12–36 months). The mean age of the patients 32 years at the time of surgery (ranged from 16 to 42years). There were 6 women and 8 men. The cause of the osteonecrosis was steroid administration in 6, alcohol abuse in 4, trauma in 3, and no apparent risk factor in 1. According to the Ficat staging system, 1 hips was stage II, 9 hips III, and 4 hips stage IV. The posterior or anterior rotational angle was 90–180° with a mean of 143°. Clinical evaluation was performed in terms of pain, walk and range of motion on the basis of Merle d'Aubigné hip scores: 17–18 points are excellent, 15–16 are good, 13–14 are fair, 12 or less are poor.

Recollapse of the final follow-up anteroposterior radiograph was prevented in 13 hips. One patient got 1 mm recollapse 18 months after surgery. No patient got progressive joint space narrowing. The Merle d'Aubigné score was excellent in 7 hips, good in 5, fair in 2.

The preliminary results suggest that modified femoral neck osteotomy through surgical hip dislocation is in favor of young patients. But longer term follow-up is necessary.

Over the past decades, computer-aided navigation system has experienced tremendous development for minimising the risks and improving the precision of the surgery. Nowadays, some commercially-available and self-developed surgical navigation systems have already been tested and proved successfully for clinical applications. However, all of these systems use computer screen to render the navigation information such as the real-time position and orientation of the surgical instrument, virtual path of preoperative surgical planning, so that the surgeons have to switch between the actual operation site and computer screen which is inconvenient and impact the continuity of surgery. In recent years, Augmented Reality (AR)- based surgical navigation is a promising technology for clinical applications. In the AR system, virtual and actual reality are mixed, offering real-time, high-quality visualisation of an extensive variety of information to the users.

Therefore, in this study, a pilot study of a surgical navigation system for orthopaedics based on optical see-through augmented reality (AR-SNS) is presented, which encompasses the preoperative surgical planning, calibration, registration, and intra-operative tracking. With the aid of AR-SNS, the surgeon wearing the optical see-through head-mounted display can obtain a fused image that the 3D virtual critical anatomical structures are aligned with the actual structures of patient in intra-operative real-world scenario, so that some disadvantages of the traditional surgical navigation are overcome (For example, surgeon is no longer obliged to switch between the real operation scenario and computer screen), and the safety, accuracy, and reliability of the surgery may be improved.

Objectives

This study aimed to explore the role of miR-320a in the pathogenesis of osteoarthritis (OA).

Mesenchymal stem cells (MSCs) are immunosuppressive and have been used to facilitate tissue repair in the context of allogeneic implantation. However, xenogeneic cell transplantation has not been fully explored. The present study investigated the feasibility of xenogeneic MSCs implantation in mice.

MSCs were harvested from the bone marrow of GFP rats (Green Fluorescent Protein transgenic rats), and cultured as previously described. 1 million GFP MSCs were loaded onto the synthetic HA/TCP porous Skelite blocks and implanted intramuscularly into the quadriceps of the MF1 and SCID mice. After 11 weeks, the implants were harvested and processed for histology examination. Upon termination, the mononuclear cells from the peripheral blood of each animal were also collected for mixed lymphocyte culture to examine lymphocyte proliferation potential and T-cell mediated cell lysis (cytotoxic) assays.

In the SCID mice, there was sparse osteoid tissue formation in the implants, whereas only dense connective tissues were seen in the implants of the MF1 mice. Osteocalcin mRNA expression was confirmed in the osteoid tissues in the implants from the SCID mice, but it was not detected in the MF1 mice by RT in situ PCR examination. Cells of GFP-rat origin were observed in both the MF1 and SCID mice (more so in the SCID mice) after 11 weeks implantation, which were confirmed by positive immunostaining of anti-GFP antibody. In the MF1 mice after 11 weeks xenogeneic MSCs implantation, the rate of lymphocyte proliferation was significantly increased when mixed with the GFP-MSCs compared to that of mixed lymphocyte culture assays in the SCID or MF1 mice without xenogeneic MSCs implantation, suggesting that implantation of xenoge-neic MSCs has promoted host anti-graft immunogenic responses towards to otherwise immunosuppressive MSCs.

In conclusion, xenogeneic rat MSCs transplanted in immunocompetent mice has survived for prolonged period, but their function was comprised to certain extent and this may be due to the increased host anti-graft immune sensitization after exposed to the xenogeneic MSCs.

Fifty-five patients undergoing isolated acetabular revisions in fifty-seven hips were available for review. In thirty-three of fifty-seven hips there was no significant acetabular deficiency; of the remaining twenty-four hips twenty underwent allograft reconstruction and four autogenous bone grafting. Mean follow-up was four years with a range of three to seven years; there have been no femoral loosening, and three further surgical procedures for hip instability. All acetabular components at last review were soundly fixed with the exception of one patient who underwent excision arthroplasty at twelve months for deep infection.

The purpose of this study was to review the functional outcome and the fate of the femoral stem and revised acetabular component following isolated ace-tabular revision.

Findings of the current study demonstrate that isolated acetabular revision does not compromise the final functional nor radiographic outcome in acetabular revision in appropriately selected patients; the fate of the femoral component is not adversely influenced by this procedure.

There is no need to remove the femoral component at the time of acetabular revision if the femoral component is well fixed and stable by pre- and intra-operative assessment.

Prospectively entered data on fifty-seven hips (fifty-five patients) who have undergone isolated acetabular revision without femoral revision was available for review. All patients were assessed pre-operatively and post-operatively on an annual basis by means of physical examination, x-ray, SF-36 and WOMAC questionnaires.

In thirty-three of fifty-seven hips there was no significant acetabular deficiency; of the remaining twenty-four hips, one had a segmental defect, thirteen had a cavitary defect and ten had a combined segmental and cavitary defect. Osteolysis existed in the proximal femur of two hips.

Bone grafting in twenty-four hips consisted of morselized allograft in nine; combined structural and morselized allograft used in eleven and autogenous bone used in four acetabular defects. Autogenous bone grafting was done in two femoral osteolytic lesions.

Mean follow-up was four years with a range of three to seven years. The mean duration of arthroplasty prior to revision was fourteen years (range four to twenty-three years).

There were no nerve palsies, vascular injuries or intra-operative fractures in this patient group. All ace-tabular components at latest review were soundly fixed with the exception of one patient who underwent excision arthroplasty at twelve months for deep infection. Twenty-one of the twenty-four hips with bone grafting demonstrated positive radiographic signs of incorporation; the remaining threehips have a stable interface but no evidence of bone ingrowth. Three of the fifty-seven hips presented with hip dislocations after revision arthroplasty; two were managed by closed reduction; the third by open reduction and soft tissue repair.