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Fulltext Tarsal tunnel syndrome caused by ganglion

Ng WM, Chan KY

Med J Malaysia, 2004 Dec;59 Suppl F:69-71.
PMID: 15941169

We report a case of delayed diagnosis of tarsal tunnel syndrome caused by a ganglion arising from the talo-calcaneal joint. Unusually the symptoms were mainly due to the lateral planter nerve compression with a positive Tinel's sign. A surgical decompression was successful in relieving the dysaesthesia in spite of a 7 years history.
Fulltext Bilateral femoral neuropathy associated with disseminated intravascular coagulopathy: a case report

Cheok CY, Merican A, Ng WM

Med J Malaysia, 2006 Feb;61 Suppl A:97-9.
PMID: 17042241

We report a case of 20-year-old man who presented with bilateral femoral nerve palsy following resuscitation for traumatic massive blood loss and its consequence. A high suspicious index for this complication may lead to its early recognition. Its related pathoanatomy is discussed based on the described evidences in the literature. Nonoperative treatment remains as a recommended option for coagulopathy-related neuropathy.
Fulltext Knowledge on Bone Banking among Participants in an Orthopaedic Conference: A Preliminary Survey

Mohd S, Yusof N, Ramalingam S, Ng WM, Mansor A

Malays Orthop J, 2017 Jul;11(2):1-6.
PMID: 29021871 MyJurnal DOI: 10.5704/MOJ.1707.004

Despite increasing use of bone graft in Malaysia, there was still lack of data to quantify knowledge level on bone banking among orthopaedic community who are involved in transplantation related work. Therefore, a survey on awareness in tissue banking specifically bone banking, usage and choice of bone grafts was conducted. From 80 respondents, 82.5% were aware about tissue banking however only 12.5% knew of the existence of tissue banks in Malaysia. Femoral head was the bone allograft most often used as a substitute to autograft. Only 34.8% respondents preferred irradiated bone grafts whilst 46.9% preferred nonirradiated, indicating the need to educate the importance of radiation for sterilising tissues. Exhibition was the most preferred medium for awareness programme to disseminate information about bone banking in the orthopaedic community. The professional awareness is necessary to increase the knowledge on the use of bone graft, hence to increase bone transplantation for musculoskeletal surgeries in the country.
Fulltext Melioidotic osteomyelitis treated with antibiotic-calcium hydroxyapatite composite: case report with four-year follow-up

Ng WM, Kwan MK, Merican AM

Singapore Med J, 2006 Jan;47(1):71-4.
PMID: 16397726

Melioidosis is caused by an infection by Burkholderia pseudomallei. Osteomyelitis is a recognised manifestation of melioidosis but Burkholderia pseudomallei is a relatively rare aetiological agent in musculoskeletal infections. We report a 32-year-old diabetic man with septicaemia due to melioidotic infection of the spleen, liver and distal femur. The osteomyelitis relapsed despite being treated with the standard radical debridement and insertion of gentamycinimpregnated polymethylmetacrylate (PMMA) beads, followed by an optimal antibiotic therapy. The PMMA-gentamycin beads were then removed. The bone defect was debrided and packed with calcium hydroxyapatite blocks filled with ceftazidime powder. The osteomyelitis was successfully treated and the patient remained free of infection four years postoperatively. Computed tomography demonstrated successful incorporation of the calcium hydroxyapatite into host bone.
Fulltext Ipsilateral femoral fracture non-union and delayed union treated by hybrid plate nail fixation and vascularized fibula bone grafting: a case report

Chan C, Ng W, Merican A

Malays Orthop J, 2013 Jul;7(2):41-4.
PMID: 25722826 MyJurnal DOI: 10.5704/MOJ.1307.015

Non-union is a well recognized complication of femoral neck fractures. The decision whether to attempt fracture fixation or to resort to hip replacement is particularly difficult in patients in the borderline age group in whom complex attempts at gaining union may fail and later present a difficult revision. On the other hand the patient may be young enough that arthroplasty best be avoided . Besides, presence of ipsilateral femoral shaft fracture with delayed union in addition to the femoral neck non-union will pose major problems at operation. We share our experience in treating a femoral neck fracture non-union with ipsilateral femoral shaft delayed union in the shaft and in the distal femur in a fifty years old patient. The fracture was treated with an angle blade plate and supracondylar nail supplemented with a free vascularised fibular bone grafting and autologous cancellous graft. There was radiological union at fourth month. At sixth months, the patient was free of pain and able to walk without support. Thus, we would like to suggest that vascularised fibula bone grafting with supracondylar nailing is a viable option for this pattern of fracture.
KEY WORDS: Vascularized fibular bone graft, neck of femur, femoral shaft fracture, non-union.
Fulltext Femoral Shaft Cortical Pathology associated with longterm Alendronate Therapy: A New Classification

Kwan M, Chan C, Ng W, Merican A, Chung W, Chan S

Malays Orthop J, 2013 Jul;7(2):12-7.
PMID: 25722819 MyJurnal DOI: 10.5704/MOJ.1307.008

There are reported cases of cortical reaction over the tension side of the normal femoral shafts in patients on long term treatment with alendronate, leading to subsequent femoral shaft fractures. We performed a retrospective review of patients with low-energy femoral shaft fracture on alendronate, admitted to our institution during the period 2004 to May 2009. The presence of radiological changes of cortical hypertrophy with or without Looser's zone over the tension side of the femoral bone (normal limb) was determined and correlated with clinical symptoms. Thirteen patients were identified. Average duration of alendronate use was 6.5 ± 3.3 years (ranges, two to 10 years). These radiological changes were noted in four patients. Average duration of alendronate usage in these four patients was 6.5 ± 2.4 years (ranges, 5 to10 years). Prodromal thigh pain was present in a patient, who had cortical hypertrophy with the presence of a Looser's zone traversing the cortex on the femoral shaft. One patient had Looser's zone limited at the lateral hypertrophied cortex without prodromal pain. The interobserver kappa coefficient was 0.96. A femoral radiograph should be performed in all patients who are on long-term alendronate therapy who present with thigh pain. We propose a new grading system based on our observation of the radiological features in these four cases. This new grading of the radiological spectrum of femoral shaft cortical pathology has the potential to stratify the risk of low energy femoral fracture for patients treated with long-term alendronate therapy.
Fulltext The incidence of deep venous thrombosis following arthroscopic knee surgery

Ng WM, Chan KY, Lim ABK, Gan EC

Med J Malaysia, 2005 Jul;60 Suppl C:14-6.
PMID: 16381276

A prospective cohort study was undertaken at two centers to look for the incidence of deep vein thrombosis (DVT) following knee arthroscopic surgery. Eighty-four patients who had 90 arthroscopic procedures were reviewed. The relevant risk factors: past or family history of DVT, smoking, oral contraceptives, body weight, haemoglobin level, platelet count, tourniquet time and type of anaesthesia were documented. All patients were subjected to preoperative and post-operative duplex ultrasound. Only one patient (1.2 %) was noted to have DVT involving the peroneal vein. We concluded that the incidence of DVT after knee arthroscopy was very low in this study population.
Fulltext Correlation between Focal Nodular Low Signal Changes in Hoffa's Fat Pad Adjacent to Anterior Femoral Cartilage and Focal Cartilage Defect Underlying This Region and Its Possible Implication

Antony CD, George J, Ng WM, Subramaniam MS

Scientifica (Cairo), 2016;2016:8675160.
PMID: 27213085 DOI: 10.1155/2016/8675160

Purpose. This study investigates the association between focal nodular mass with low signal in Hoffa's fat pad adjacent to anterior femoral cartilage of the knee (FNMHF) and focal cartilage abnormality in this region. Method. The magnetic resonance fast imaging employing steady-state acquisition sequence (MR FIESTA) sagittal and axial images of the B1 and C1 region (described later) of 148 patients were independently evaluated by two reviewers and categorized into four categories: normal, FNMHF with underlying focal cartilage abnormality, FNMHF with normal cartilage, and cartilage abnormality with no FNMHF. Results. There was a significant association (p = 0.00) between FNMHF and immediate adjacent focal cartilage abnormality with high interobserver agreement. The absence of focal nodular lesions next to the anterior femoral cartilage has a very high negative predictive value for chondral injury (97.8%). Synovial biopsy of focal nodular lesion done during arthroscopy revealed some fibrocollagenous tissue and no inflammatory cells. Conclusion. We postulate that the FNMHF adjacent to the cartilage defects is a form of normal healing response to the cartilage damage. One patient with FHMHF and underlying cartilage abnormality was rescanned six months later. In this patient, the FNMHF disappeared and normal cartilage was observed in the adjacent region which may support this theory.
Fulltext Localised pigmented villonodular synovitis presenting as anterior knee pain

Goh JH, Saravanan S, Ng WM, Looi LM, Ali R

Malays Orthop J, 2010;4(1):50-52.
MyJurnal

We report a case of a 21 years old female who presented with a history of anterior knee pain for previous 3 months. Pain was localized to the anteromedial aspect of the left knee and aggravated by flexion. Clinical examination revealed a 2x2cm painful lump on the anteromedial aspect of the left medial condyle with no effusion. Magnetic resonance imaging revealed an anterosuperior tear of the medial collateral ligament. The patient subsequently underwent left knee arthroscopic examination. Two yellowish pedunculated masses arising from the anteromedial portion of the synovium were discovered and completely excised. Histopathological examination of the excision biopsy revealed pigmented villonodular synovitis (PVNS) with marked central necrosis. One year post excision, she is well with no signs or symptoms of recurrence. This case highlights an uncommon cause of anterior knee pain. Localized PVNS typically presents with mechanical symptoms, however, pain could arise from pedicle torsion and necrosis.
Exploring the Impact of Surface Functionalization on the Reaction, Magnetophoretic, and Collective Transport Behavior of Nanoscale Zerovalent Iron

Ng WM, Chong WH, Abdullah AZ, Lim J

Langmuir, 2023 Dec 05;39(48):17270-17285.
PMID: 37976676 DOI: 10.1021/acs.langmuir.3c02358

This study provides a systematic analysis of the transport and magnetophoretic behavior of nanoscale zerovalent iron (nZVI) particles, both bare and surface functionalized by poly(ethylene glycol) (PEG) and carboxymethyl cellulose (CMC), after undergoing a chemical reaction. Here, a simple and well-investigated chemical reaction of methyl orange (MO) degradation by nZVI was used as a model reaction system, and the sand column transport and low-gradient magnetophoretic profiles of the nanoparticles were measured before and after the reaction. The results were compared over time and analyzed in the context of extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to understand the particle interactions involved. The colloidal stability of both bare and functionalized nZVI particles was enhanced after the reaction due to the consumption of metallic Fe content, resulting in a significant drop in their magnetic properties. As a result, they exhibited improved mobility across the sand column and a slower magnetophoretic collection rate compared to the unreacted particles. Here, the colloidal filtration theory (CFT) was employed to analyze the transport behavior of nZVI particles across the packed sand column. It has been observed that the surface properties of the reacted functionalized particles changed, possibly due to the entrapment of degraded products within the polymer adlayer. Moreover, quartz crystal microbalance with dissipation (QCM-D) measurements were performed to reveal the viscoelastic contribution of the adlayer formed by both bare and functionalized nZVI particles after the reaction on influencing their transport behavior across the sand column. Finally, we proposed the implementation of a high-gradient magnetic trap (HGMT) to reduce the transport distance of the colloidally stable CMC-nZVI, both before and after the reaction. This study sheds light on the behavioral changes of iron nanoparticles after the reaction and highlights environmental concerns regarding the presence of reacted nanoparticles.
Effect of growth differentiation factor 5 on the proliferation and tenogenic differentiation potential of human mesenchymal stem cells in vitro

Tan SL, Ahmad RE, Ahmad TS, Merican AM, Abbas AA, Ng WM, et al.

Cells Tissues Organs (Print), 2012;196(4):325-38.
PMID: 22653337

The use of growth differentiation factor 5 (GDF-5) in damaged tendons has been shown to improve tendon repair. It has been hypothesized that further improvements may be achieved when GDF-5 is used to promote cell proliferation and induce tenogenic differentiation in human bone marrow-derived mesenchymal stem cells (hMSCs). However, the optimal conditions required to produce these effects on hMSCs have not been demonstrated in previous studies. A study to determine cell proliferation and tenogenic differentiation in hMSCs exposed to different concentrations of GDF-5 (0, 5, 25, 50, 100 and 500 ng/ml) was thus conducted. No significant changes were observed in the cell proliferation rate in hMSCs treated at different concentrations of GDF-5. GDF-5 appeared to induce tenogenic differentiation at 100 ng/ml, as reflected by (1) a significant increase in total collagen expression, similar to that of the primary native human tenocyte culture; (2) a significant upregulation in candidate tenogenic marker gene expression, i.e. scleraxis, tenascin-C and type-I collagen; (3) the ratio of type-I collagen to type-III collagen expression was elevated to levels similar to that of human tenocyte cultures, and (4) a significant downregulation of the non-tenogenic marker genes runt-related transcription factor 2 and sex determining region Y (SRY)-box 9 at day 7 of GDF-5 induction, further excluding hMSC differentiation into other lineages. In conclusion, GDF-5 does not alter the proliferation rates of hMSCs, but, instead, induces an optimal tenogenic differentiation response at 100 ng/ml.
Fulltext Identification of Pathways Mediating Growth Differentiation Factor5-Induced Tenogenic Differentiation in Human Bone Marrow Stromal Cells

Tan SL, Ahmad TS, Ng WM, Azlina AA, Azhar MM, Selvaratnam L, et al.

PLoS One, 2015;10(11):e0140869.
PMID: 26528540 DOI: 10.1371/journal.pone.0140869

To date, the molecular signalling mechanisms which regulate growth factors-induced MSCs tenogenic differentiation remain largely unknown. Therefore, a study to determine the global gene expression profile of tenogenic differentiation in human bone marrow stromal cells (hMSCs) using growth differentiation factor 5 (GDF5) was conducted. Microarray analyses were conducted on hMSCs cultures supplemented with 100 ng/ml of GDF5 and compared to undifferentiated hMSCs and adult tenocytes. Results of QuantiGene® Plex assay support the use and interpretation of the inferred gene expression profiles and pathways information. From the 27,216 genes assessed, 873 genes (3.21% of the overall human transcriptome) were significantly altered during the tenogenic differentiation process (corrected p<0.05). The genes identified as potentially associated with tenogenic differentiation were ARHGAP29, CCL2, integrin alpha 8 and neurofilament medium polypeptides. These genes, were mainly associated with cytoskeleton reorganization (stress fibers formation) signaling. Pathway analysis demonstrated the potential molecular pathways involved in tenogenic differentiation were: cytoskeleton reorganization related i.e. keratin filament signaling and activin A signaling; cell adhesion related i.e. chemokine and adhesion signaling; and extracellular matrix related i.e. arachidonic acid production signaling. Further investigation using atomic force microscopy and confocal laser scanning microscopy demonstrated apparent cytoskeleton reorganization in GDF5-induced hMSCs suggesting that cytoskeleton reorganization signaling is an important event involved in tenogenic differentiation. Besides, a reduced nucleostemin expression observed suggested a lower cell proliferation rate in hMSCs undergoing tenogenic differentiation. Understanding and elucidating the tenogenic differentiation signalling pathways are important for future optimization of tenogenic hMSCs for functional tendon cell-based therapy and tissue engineering.
Fulltext A Biomechanical and Ease of Learning Comparison Study of Arthroscopic Sliding Knots

Teo SH, Ng WM, Abd Rahim MR, Al-Fayyadh MZM, Ali MRM

Indian J Orthop, 2020 Apr;54(2):168-173.
PMID: 32257034 DOI: 10.1007/s43465-019-00024-2

Introduction: This study aims to compare the biomechanical properties and ease of learning and tying of our novel knot (UM Knot) with other commonly used arthroscopic sliding knots.
Materials and methods: The Duncan, HU, SMC, Pretzel, Nicky's and square knots were selected for comparisons with UM knot. All knots were prepared with size 2 HiFi® suture by a single experienced surgeon and tested with cyclic loading and load to failure tests. The ease of learning was assessed objectively by recording the time to learn the first correct knot and the total number of knots completed in 5 min by surgeons and trainees.
Results: The UM knot average failure load is significantly superior to the HU knot (p
Low-Cost Self-Made Arthroscopic Training Camera Is Equally as Effective as Commercial Camera: A Comparison Study

Ling JL, Teo SH, Mohamed Al-Fayyadh MZ, Mohamed Ali MR, Ng WM

Arthroscopy, 2019 02;35(2):596-604.
PMID: 30611592 DOI: 10.1016/j.arthro.2018.08.038

PURPOSE: To assess the effectiveness of a low-cost self-made arthroscopic camera (LAC) in basic arthroscopic skills training compared with a commercial arthroscopic camera (CAC).
METHODS: One hundred fifty-three orthopaedic residents were recruited and randomly assigned to either the LAC or CAC. They were allocated 2 practice sessions, with 20 minutes each, to practice 4 given arthroscopic tasks: task 1, transferring objects; task 2, stacking objects; task 3, probing numbers; and task 4, stretching rubber bands. The time taken for participants to complete the given tasks was recorded in 3 separate tests; before practice, immediately after practice, and after a period of 3 months. A comparison of the time taken between both groups to complete the given tasks in each test was measured as the primary outcome.
RESULTS: Significant improvements in time completion were seen in the post-practice test for both groups in all given arthroscopic tasks, each with P < .001. However, there was no significant difference between the groups for task 1 (P = .743), task 2 (P = .940), task 3 (P = .932), task 4 (P = .929), and total (P = .944). The outcomes of the tests (before practice, after practice, and at 3 months) according to repeated measures analysis of variance did not differ significantly between the groups in task 1 (P = .475), task 2 (P = .558), task 3 (P = .850), task 4 (P = .965), and total (P = .865).
CONCLUSIONS: The LAC is equally as effective as the CAC in basic arthroscopic skills training with the advantage of being cost-effective.
CLINICAL RELEVANCE: In view of the scarcity in commercial arthroscopic devices for trainees, this low-cost device, which trainees can personally own and use, may provide a less expensive and easily available way for trainees to improve their arthroscopic skills. This might also cultivate more interest in arthroscopic surgery among junior surgeons.
Characterisation of a cryptic plasmid from an Antarctic bacterium Pedobacter cryoconitis strain BG5

Wong CM, Tam HK, Ng WM, Boo SY, González M

Plasmid, 2013 Mar;69(2):186-93.
PMID: 23266397 DOI: 10.1016/j.plasmid.2012.12.002

A cryptic plasmid, pMWHK1 recovered from an Antarctic bacterium Pedobacter cryoconitis BG5 was sequenced and characterised. The plasmid is a circular 6206bp molecule with eight putative open reading frames designated as orf1, orf2, orf3, orf4, orf5, orf6, orf7 and orf8. All the putative open reading frames of pMWHK1 are found to be actively transcribed. Proteins encoded by orf2 and orf4 are predicted to be responsible for the mobilization and replication of the plasmid respectively. orf4 shares 55% and 61% identities with the theta-type Rep proteins from two strains of Riemerella anatipestifer. This suggests that pMWHK1 could be a member of the theta-type replicating plasmid. The origin of replication is located within the AT-rich region upstream of orf4. orf5 and orf6 encode bacterial toxin-antitoxin proteins predicted to maintain plasmid stability. orf3 encodes an entry exclusion protein that is hypothetically involved in reducing the frequency of DNA transfer through conjugation. orf1, orf7 and orf8 encode proteins with unknown functions. Plasmid, pMWHK1 is stably maintained in P. cryoconitis BG5 at 20°C.
Magnetophoresis of Magnetic Pickering Emulsions Under Low Field Gradient: Macroscopic and Microscopic Motion

Tham FK, Ng WM, Leong SS, Yeap SP, Low SC, Lee HL, et al.

Langmuir, 2021 Jan 26.
PMID: 33496594 DOI: 10.1021/acs.langmuir.0c03153

Monodispersed iron oxide nanoparticles (IONPs) coated with polystyrenesulfonate (PSS) and cetrimonium bromide (CTAB) have been used to stabilize magnetic Pickering emulsions (MPEs). Magnetophoresis of MPEs under the influence of a low gradient magnetic field (∇B < 100 T/m) was investigated at the macroscopic and microscopic scale. At the macroscopic scale, for the case of pH 7, the MPE achieved a magnetophoretic velocity of 70.9 μm/s under the influence of ∇B at 93.8 T/m. The magnetic separation efficiency of the MPE at 90% was achieved within 30 min for pH 3, 7, and 10. At pH 10, the colloidal stability of the MPE was the lowest compared to that for pH 3 and 7. Thus, MPE at pH 10 required the shortest time for achieving the highest separation efficiency, as the MPE experienced cooperative magnetophoresis at alkaline pH. The creaming rate of the MPE at all conditions was still lower compared to magnetophoresis and was negligible in influencing its separation kinetics profiles. At the microscopic scale, the migration pathways of the MPEs (with diameters between 2.5 and 7.5 μm) undergoing magnetophoresis at ∇B ∼ 13.0 T/m were recorded by an optical microscope. From these experiments, and taking into consideration the MPE size distribution from the dynamic light scattering (DLS) measurement, we determined the averaged microscopic magnetophoretic velocity to be 7.8 ± 5.5 μm/s. By making noncooperative magnetophoresis assumptions (with negligible interactions between the MPEs along their migration pathways), the calculated velocity of individual MPEs was 9.8 μm/s. Such a value was within the percentage error of the experimental result of 7.8 ± 5.5 μm/s. This finding allows for an easy and quick estimation of the magnetophoretic velocity of MPEs at the microscale by using macroscopic separation kinetics data.
Fulltext Soft-Tissue Loop for Medial Patellofemoral Ligament Reconstruction

Miswan MF, Al-Fayyadh MZ, Seow Hui T, Mohamed Ali MR, Ng WM

Arthrosc Tech, 2016 Apr;5(2):e321-7.
PMID: 27354953 DOI: 10.1016/j.eats.2016.01.003

A patient with patellar instability frequently presents with anterior knee pain, patellar subluxation, or dislocation. Medial patellofemoral ligament (MPFL) has a key role for normal patella tracking and stability. Reconstruction of the MPFL using a hamstring graft is a commonly used procedure for the treatment of chronic lateral subluxation of patella. Anchor sutures and bony tunnels are used for the patellar attachment of the graft. This can be associated with complications such as patella fracture; besides, it does not produce an anatomical reconstruction for the native MPFL that can alter the direction of tension applied on the patella. To overcome these problems, a soft-tissue loop technique is used for MPFL reconstruction. During this procedure, a semitendinosus graft was passed through the prepatellar extensor retinaculum and secured with sutures. The free ends of the graft were then passed between the second and third layers of the medial patellofemoral retinaculum and fixed to a femoral tunnel on the medial femoral condyle with an interference screw. The desired amount of tension on the graft is achieved under direct vision of patella tracking arthroscopically. We found this method to be relatively safe and fast. It is more anatomical and can avoid the complications during the conventional bony procedures.
Elevated plasma and synovial fluid interleukin-8 and interleukin-18 may be associated with the pathogenesis of knee osteoarthritis

Koh SM, Chan CK, Teo SH, Singh S, Merican A, Ng WM, et al.

Knee, 2020 Jan;27(1):26-35.
PMID: 31917106 DOI: 10.1016/j.knee.2019.10.028

PURPOSE: Osteoarthritis (OA) of the knee is a multifactorial degenerative disease typically defined as the 'wear and tear' of articular joint cartilage. However, recent studies suggest that OA is a disease arising from chronic low-grade inflammation. We conducted a study to investigate the relationship between chronic inflammatory mediators present in both the systemic peripheral blood system and localised inflammation in synovial fluid (SF) of OA and non-OA knees; and subsequently made direct comparative analyses to understand the mechanisms that may underpin the processes involved in OA.
METHODS: 20-Plex proteins were quantified using Human Magnetic Luminex® assay (R&D Systems, USA) from plasma and SF of OA (n = 14) and non-OA (n = 14) patients. Ingenuity Pathway Analysis (IPA) software was used to predict the relationship and possible interaction of molecules pertaining to OA.
RESULTS: There were significant differences in plasma level for matrix metalloproteinase (MMP)-3, interleukin (IL)-27, IL-8, IL-4, tumour necrosis factor-alpha, MMP-1, IL-15, IL-21, IL-10, and IL-1 beta between the groups, as well as significant differences in SF level for IL-15, IL-8, vascular endothelial growth factor (VEGF), MMP-1, and IL-18. Our predictive OA model demonstrated that toll-like receptor (TLR) 2, macrophage migration inhibitory factor (MIF), TLR4 and IL-1 were the main regulators of IL-1B, IL-4, IL-8, IL-10, IL-15, IL-21, IL-27, MMP-1 and MMP-3 in the plasma system; whilst IL-1B, TLR4, IL-1, and basigin (BSG) were the regulators of IL-4, IL-8, IL-10, IL-15, IL-18, IL-21, IL-27, MMP-1, and MMP-3 in the SF system.
CONCLUSION: The elevated plasma IL-8 and SF IL-18 may be associated with the pathogenesis of OA via the activation of MMP-3.
Sedimentation Kinetics of Magnetic Nanoparticle Clusters: Iron Oxide Nanospheres vs Nanorods

Ng WM, Katiyar A, Mathivanan V, Teng XJ, Leong S, Low S, et al.

Langmuir, 2020 May 19;36(19):5085-5095.
PMID: 32338911 DOI: 10.1021/acs.langmuir.0c00135

A detailed study of the sedimentation kinetics of iron oxide nanoparticle (IONP) clusters composed of nanospheres and nanorods is presented. Measurements were performed to determine the absorbance of an IONP suspension undergoing sedimentation over time by using a UV-vis spectrophotometer with simultaneous monitoring of the hydrodynamic diameter of the clusters formed with dynamic light scattering (DLS). Mathematical analysis based on Happel's spherical and cylindrical models was conducted to reveal the relationship between the settling velocity of the IONP clusters and their packing density. For the case of IONP clusters composed of rodlike particles, two distinctive phases of sedimentation were recorded, with the occurrence of rapid sedimentation at the beginning of the process (phase I) followed by a slower settling rate (phase II). In sedimentation phase II, even though the nanorod clusters had a hydrodynamic size of >500 nm, which was much larger than that of the nanosphere clusters (∼200 nm), their settling velocity of 0.0038 mm/min was still slower than that of the nanosphere clusters. Such observations were mainly a result of the packing density differences between the formed clusters; due to the end-to-end particle interactions of nanorods, the nanorod clusters were less tightly packed and more permeable. In addition to the mathematical analysis, quartz crystal microbalance with dissipation (QCM-D) was employed to measure the "softness" of the IONP clusters formed, and this physical property can be further related to their packing density. This study illustrated that for a rapidly aggregating system, such as magnetic IONPs, not only do the particle shape and size uniformity contribute to the physical properties of the particle clusters formed but also the nature of the aggregation, either end-to-end and/or side-to-side, should be carefully considered when designing a colloidally stable IONP suspension.
Fulltext Crossing Suture Technique for the Osteochondral Fractures Repair of Patella

Ng WM, Al-Fayyadh MZM, Kho J, Seow Hui T, Mohamed Ali MRB

Arthrosc Tech, 2017 Aug;6(4):e1035-e1039.
PMID: 28970989 DOI: 10.1016/j.eats.2017.03.020

Osteochondral fracture of the patella is a common concomitant injury of the knee, especially in lateral patellar instability, and the importance of early stable fixation with minimal complication and early mobilization should be emphasized. Screws and Kirschner wires both absorbable and nonabsorbable have been the common mode of fixation of these fractures. Nevertheless, these fixation techniques require larger osteochondral fragments and are associated with cartilage abrasion, hardware prominence, synovitis, and foreign body reaction. In contrast, suture fixation can adequately stabilize smaller osteochondral fragments without comminution and prevent some of the possible complications of other techniques of fixation. We created 4 holes in a rectangular pattern on the patella oriented perpendicular to its anteroposterior surface. We used readily available, and affordable, no. 2 Ultrabraid sutures inserted into the holes and looped around the osteochondral fragment, compressing it to the patella. The technique is very simple and is relatively easy to learn. It provides secure fixation and allows early mobilization. And it spares the knee from subsequent surgical procedure for removal of metallic implants.

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