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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_18 | Pages 40 - 40
14 Nov 2024
Siverino C Sun Q Yang D Solomon B Moriarty F Atkins G
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Introduction

Bone and joint infection (BJI) is often characterized by severe inflammation and progressive bone destruction. Osteocytes are the most numerous and long-lived bone cell type, and therefore represent a potentially important long-term reservoir of bacterial infection. Staphylococcus aureus is known to establish stable intracellular osteocytic infections, however, little is known about the less virulent yet second most prevalent BJI pathogen, S. epidermidis, associated with late-diagnosed, chronic BJI. Thus, this study sought to establish an in vitro model to study the infection characteristics of S. epidermidis in human osteocyte-like cells.

Methods

SaOS2 cells (1 ×104 cells/cm2) were grown to confluence either without differentiation, representing an osteoblast-like (OB) state (SaOS2-OB) or differentiated to an osteocyte-like stage (SaOS2-OY), using established methods. Four S. epidermidis strains used (ATCC-12228, ATCC-14990, ATCC-35984 and a clinical osteomyelitis strain RAH-SE1) were tested to be Lysostaphin-resistant, necessitating antibiotic (Levofloxacin) control of extracellular bacteria. Infection of host cells (OB or OY) was tested at three multiplicities of infection (MOI: 10, 100 and 1000). Extracellular bacteria were controlled by overnight incubation at a 10X minimum inhibitory concentration (MIC) of Levofloxacin and thereafter at 1XMIC. At each time point (days 1, 3, 5) viable intra- and extracellular bacteria were quantified.


The Bone & Joint Journal
Vol. 106-B, Issue 9 | Pages 964 - 969
1 Sep 2024
Wang YC Song JJ Li TT Yang D Lv ZB Wang ZY Zhang ZM Luo Y

Aims

To propose a new method for evaluating paediatric radial neck fractures and improve the accuracy of fracture angulation measurement, particularly in younger children, and thereby facilitate planning treatment in this population.

Methods

Clinical data of 117 children with radial neck fractures in our hospital from August 2014 to March 2023 were collected. A total of 50 children (26 males, 24 females, mean age 7.6 years (2 to 13)) met the inclusion criteria and were analyzed. Cases were excluded for the following reasons: Judet grade I and Judet grade IVb (> 85° angulation) classification; poor radiograph image quality; incomplete clinical information; sagittal plane angulation; severe displacement of the ulna fracture; and Monteggia fractures. For each patient, standard elbow anteroposterior (AP) view radiographs and corresponding CT images were acquired. On radiographs, Angle P (complementary to the angle between the long axis of the radial head and the line perpendicular to the physis), Angle S (complementary to the angle between the long axis of the radial head and the midline through the proximal radial shaft), and Angle U (between the long axis of the radial head and the straight line from the distal tip of the capitellum to the coronoid process) were identified as candidates approximating the true coronal plane angulation of radial neck fractures. On the coronal plane of the CT scan, the angulation of radial neck fractures (CTa) was measured and served as the reference standard for measurement. Inter- and intraobserver reliabilities were assessed by Kappa statistics and intraclass correlation coefficient (ICC).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 78 - 78
1 Jul 2020
Atkins G Yang D Wijenayaka A Kidd S Solomon L Gunn N Findlay D
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Periprosthetic joint infection (PJI) is a potentially devastating complication of joint replacement surgery. Osteocytes comprise 90–95% of all cells in hard bone tissue, are long-lived and are becoming increasingly recognised as a critical cell type in the regulation of bone and systemic physiology. The purpose of this study was to examine role of these cells in PJI pathophysiology and aetiology, with the rationale that their involvement could contribute to the difficulty in detecting and clearing PJI. This study examined the ability of human osteocytes to become infected by Staphylococcus aureus and the responses of both the host cell and pathogen in this scenario.

Several S. aureus (MRSA) strains were tested for their ability to infect human primary osteocyte-like cells in vitro and human bone samples ex vivo. Bone biopsies were retrieved from patients undergoing revision total hip arthroplasty for either aseptic loosening associated with osteolysis, or for PJI. Retrieved bacterial colony number from cell lysates and colony morphology were determined. Gene expression was measured by microarray/bioinformatics analysis and/or real-time RT-PCR.

Exposure to planktonic S. aureus (approx. 100 CFU/cell) resulted in intracellular infection of human osteocyte-like cells. We found no evidence of increased rates of osteocyte cell death in bacteria exposed cultures. Microarray analysis of osteocyte gene expression 24h following exposure revealed more than 1,500 differentially expressed genes (fold-change more than 2, false discovery rate p < 0.01). The gene expression patterns were consistent with a strong innate immune response and altered functionality of the osteocytes. Consistent patterns of host gene expression were observed between experimentally infected osteocyte-like cultures and human bone, and in PJI patient bone samples. Internalised bacteria switched to the quasi-dormant small colony variant (SCV) form over a period of 5d, and the ensuing infection appeared to reach a stable state. S. aureus infection of viable osteocytes was also identified in bone taken from PJI patients.

We have demonstrated [1] that human osteocytes can become infected by S. aureus and respond robustly by producing immune mediators. The bony location of the infected osteocyte may render them refractory to clearance by immune cells, and osteocytes may therefore be an immune-privileged cell type. The phenotypic switch of S. aureus to SCV, a form less sensitive to most antibiotics and one associated with intracellular survival, suggests that infection of osteocytes may contribute to a chronic disease state. The osteocyte may therefore serve as a reservoir of bacteria for reinfection, perhaps explaining the high prevalence of infections that only become apparent after long periods of time or recur following surgical/medical treatment. Our findings also provide a biological rationale for the recognised need for aggressive bone debridement in the surgical management of PJI.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 70 - 70
1 Feb 2020
Huang Y Zhou Y Yang D Tang H Shao H Guo S
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Aims

Only a small number of studies exist that report the results of EBM-produced porous coated trabecular titanium cups in primary total hip arthroplasty (THA). This study aims to investigate the patient satisfaction level, clinical function and radiographic outcomes of the patients who underwent THA using an EBM-produced porous coated titanium cup.

Patients and Methods

A total of 32 patients who underwent primary THA with using an EBM-produced porous coated titanium cup from five hospitals between May and December, 2012 were retrospectively reviewed. Five patients were lost prior to the minimum 6-year follow-up. Clinical and radiographic outcomes were analyzed with an average follow-up of 81.48 (range: 77.00–87.00) months.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 101 - 101
1 Feb 2020
Deng W Wang Z Zhou Y Shao H Yang D Li H
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Background

Core decompression (CD) is effective to relieve pain and delay the advent of total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH). However, the influence of CD on the subsequent THA has not been determined yet.

Methods

Literatures published up to and including November 2018 were searched in PubMed, Embase and the Cochrane library databases with predetermined terms. Comparative studies of the clinical outcomes between conversion to THA with prior CD (the Prior CD group) and primary THA (the Control group) for ONFH were included. Data was extracted systematically and a meta- analysis was performed.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 147 - 147
1 Feb 2020
Yang D Huang Y Zhou Y Zhang J Shao H Tang H
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Aims

The incidence of thigh pain with the short stem varies widely across different studies. We aimed to evaluate the incidence and characteristics of post-operative thigh pain after using a particular bladed short stem and its potential risk factors.

Patients and Methods

We respectively reviewed 199 consecutive patients who underwent unilateral total hip replacement using the Tri-lock stem from 2013–2016, of which 168 patients were successfully followed up with minimum two year clinical follow-up. All information about thigh pain and pre- and postoperative HHS score were gathered and all preoperative and immediate postoperative radiographs were available for review. Any complications were recorded.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_5 | Pages 19 - 19
1 Apr 2019
Zhou Y Huang Y Tang H Guo S Yang D Zhou B
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Background

Failed ingrowth and subsequent separation of revision acetabular components from the inferior hemi-pelvis constitutes a primary mode of failure in revision total hip arthroplasty (THA). Few studies have highlighted other techniques than multiple screws and an ischial flange or hook of cages to reinforce the ischiopubic fixation of the acetabular components, nor did any authors report the use of porous metal augments in the ischium and/or pubis to reinforce ischiopubic fixation of the acetabular cup. The aims of this study were to introduce the concept of extended ischiopubic fixation into the ischium and/or pubis during revision total hip arthroplasty [Fig. 2], and to determine the early clinical outcomes and the radiographic outcomes of hips revised with inferior extended fixation.

Methods

Patients who underwent revision THA utilizing the surgical technique of extended ischiopubic fixation with porous metal augments secured in the ischium and/or pubis in a single institution from 2014 to 2016 were reviewed. 16 patients were included based on the criteria of minimum 24 months clinical and radiographic follow-up. No patients were lost to follow-up. The median duration of follow-up for the overall population was 37.43 months. The patients' clinical results were assessed using the Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and Short form (SF)-12 score and satisfaction level based on a scale with five levels at each office visit. All inpatient and outpatient records were examined for complications, including infection, intraoperative fracture, dislocation, postoperative nerve palsy, hematoma, wound complication and/or any subsequent reoperation(s). The vertical and horizontal distances of the center of rotation to the anatomic femoral head and the inclination and anteversion angle of the cup were measured on the preoperative and postoperative radiographs. All the postoperative plain radiographs were reviewed to assess the stability of the components.


Bone & Joint Research
Vol. 6, Issue 9 | Pages 535 - 541
1 Sep 2017
Zan P Mol MO Yao JJ Fan L Yang D Liu K Li G

Objectives

The length of the tourniquet time during total knee arthroplasty (TKA) is related to the incidence of post-operative deep vein thrombosis (DVT). Our aim in this study was to investigate the effect of the early release of the tourniquet on the incidence of DVT in patients undergoing TKA.

Methods

A total of 200 patients who underwent TKA between November 2015 and November 2016 were prospectively enrolled. The tourniquet was inflated before surgery and released immediately after the introduction of the components (early release group). This group was compared with a retrospective cohort of 200 primary TKAs, in which the tourniquet was released after the dressings had been applied (late release group). The presence of a DVT was detected using bilateral lower limb ultrasonography. Peri-operative clinical and follow-up data were collected for analysis.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 64 - 64
1 Jan 2016
Tang H Zhou Y Yang D Guo S Chen H Wang Z
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Background

Soft tissue tension and intra-articular pressure distribution plays a crucial role in postoperative function and survivorship of TKA prosthesis. Although posterior stabilized (PS) and cruciate retaining (CR) knees have both been successful in relieving pain and restore function, it is reported that the joint gaps were significantly distinct between the two designs during flexion. The aim of this study is to find out what is the difference in intra-articular pressure distribution between PS and CR knees.

Methods

We prospectively included 45 consecutive patients (50 knees) scheduled for total knee arthroplasty between August, 2013 and April, 2014 in our hospital. 23 patients (25 osteoarthritic knees) received a Genesis II CR TKA (Smith & Nephew, Memphis, USA), and the other 22 patients (25 osteoarthritic knees) received Genesis II PS TKA (Smith & Nephew, Memphis, USA). During operation, after the bone osteotomy and soft tissue balance were completed, we measured and compared the intra-articular pressure distribution at 0°, 30°, 45°, 60°, 90°, and 120° flexion with a previously validated “Wireless Force Measurement System (WFMS)”. Joint gaps were measured at extension and 90° flexion. The soft tissue was not considered balanced until the medial and lateral joint gap difference ≤ 2mm at extension and 90° flexion. There are no significant differences in age, gender, BMI, varus angle and flexion deformity, and preoperative range of motion between the two groups. The medial-lateral pressure distribution and total pressure were compared at different angles between CR and PS knees.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 152 - 152
1 Jan 2016
Tang H Zhou Y Yang D Guo S Tang J Liu J
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Background

The development of T-smart tomosynthesis has greatly improved the imaging quality of THA by reducing the peri-implant artifacts. In order to find out whether these improvements could lead to diagnostic advantages on stability of cementless THA arthroplasty components, we conducted a diagnostic research by comparing T-smart tomosynthesis, X-ray, and computed tomography.

Methods

We retrospectively included 48 patients who undergone THA revisions in our center between Aug, 2013 and Mar, 2014. For patients with hybrid fixation as their primary prosthesis, the femoral or acetabular components with cement fixation were excluded. There were 41 cementless femoral stems and 35 cementless acetabular cups remained for evaluation. All patients took anterior-posterior and lateral view x-ray examination, anterior-posterior T-smart tomosynthesis scan, and computed tomography before revision surgery. As the gold standard, intraoperative pull-out tests and twisting tests were done for every patient to examine the stability of all implants. 7 orthopedic surgeons evaluated the preoperative images independently, who were divided into the senior group (3 doctors with 6∼13 years’ clinical experience) and the junior group (4 doctors with 2∼4 years’ clinical experience). The x-rays were evaluated first, followed by computed tomography 4 weeks later, and after another 4 weeks’ interval the T-smart tomosynthesis were assessed. All doctors used the same criteria for diagnosis. Diagnostic accuracy for each imaging examination was calculated by comparing with the results of intraoperative tests. The diagnostic accuracy, kappa values between 3 imaging techniques were calculated, and chi-square tests were conducted to examine the difference between the senior and junior groups for each technique.


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 263 - 263
1 Nov 2002
Jung Y Tae S Yang D Han J
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Purpose: The aim of this study was to elucidate the continiuty of ligament in chronic injury of the posterior cruciate ligament(PCL).

Method: Magnetic resonance imaging(MRI) of twenty-six PCL injury patients with grade II or III laxity and more than 5mm side to side difference on stress radiographs were reviewed in terms of ligamentous continuity and thickness of the ligament at average 7.2 months(range:1–36) after injury. The results were compared with arthroscopic findings in fifteen patients.

Results: Eighteen PCLs(69%) showed continuity of PCL, in which average thickness of the injured portion was 61% of the intact portion. When thickness of the ligament in cases without continuity was rated as zero, the average thickness of the PCLs as compared to intact portion of the ligament increased as the time from injury elapsed; 16.4% in 0–2 months group (7 cases), 30.0% in 3–5 months group (6 cases), 53.8% in 6–8 months group (9 cases) and 80.0% in over 9 months group (4 cases). Of the fifteen cases with confirmed continuity of PCL in arthroscopic examination, nine cases showed continuity on MRI, while the remaining six cases didn’t.

Conclusion: More than two thirds of PCLs in symptomatic chronic injury showed ligamentous continuity on MRI. The longer the interval from injury was, the thicker the PCL was. In cases over 6 months after injury, the PCLs were of more than 50% thickness of the intact portion.


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 263 - 263
1 Nov 2002
Jung Y Tae S Yang D Lee J
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Purpose: To introduce modified tibial inlay technique for autogenous bone-patellar tendon-bone (BPTB) posterior cruciate ligament (PCL) reconstruction and evaluate the outcomes of PCL reconstruction by this method.

Methods: Fifty patients who underwent autogenous BPTB PCL reconstruction using modified tibial inlay technique were evaluated at average 30.9 months (range 12–52).

The outcomes were assessed by stress radiographs, maximal manual test with KT-2000 arthrometer, IKDC grading and OAK knee score.

Results: Average side to side difference in push view with Telos stress device decreased from 11.7mm to 3.2mm. Difference in maximal manual test with KT-2000 arthrometer also decreased from 11.5mm to 3.1mm. Final IKDC grading was A in six patients, B in thirty four, C in nine and D in one.

Average OAK score improved from 64.3 to 86.4

Conclusion: We consider that the modified tibial inlay technique is a method to reduce technical effort and contribute to satisfactory clinical results in autogenous BPTB PCL reconstruction.