Synergetic impact of MgO on PMMA-ZrO2 hybrid composites: Evaluation of structural, morphological and improved mechanical behavior for dental applications.

This work aims to demonstrate the effect of ZrO2 and MgO inclusion into the Poly(methyl methacrylate) (PMMA). To fabricate novel hybrid composites via heat cure method, various composites (PZM2, PZM4 and PZM6) were synthesized in the system [(95-x) PMMA + 5 ZrO2 + x MgO] (x = 2, 4, and 6) respectively. Density of the prepared composites were determined and varying between 1.035-1.152 g/cm3. X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) followed by EDAX and mechanical testing were performed to evaluate the fabricated composite properties. Moreover, to explore the structure of the fabricated composites the 13 C CP-MAS SSNMR and 1 H-13 C Phase-Modulated Lee Goldberg (PMLG) HETCOR Spectrum were recorded which clarify chemical shifting and motional dynamics of the composites. Mechanical tests were performed by UTM and the obtained parameters such as compressive strength, Young's modulus, fracture toughness, brittleness coefficient, flexural strength and flexural modulus are found to be in the range of 91-100 MPa, 0.48-0.51 GPa, 9.122-9.705 MPa.m1/2, 0.66-0.815, 51.03-42.78 MPa and 499-663 MPa respectively. Some more mechanical parameters such as proportional limit, elastic limit, failure strength, modulus of resilience and modulus of toughness were also calculated. Furthermore, tribological properties were also determined and the coefficient of friction (COF) was decreased by 17.4 % and 38 % for composite PZM6 at 20 N and 40 N as compared to the composite PZM2 and the lowest wear volume of 1.55 mm3 was observed for PZM2, whereas the maximum volume loss of 5.64 mm3 is observed for composite PZM6. To check out the biocompatibility, cytotoxicity and genotoxicity of the fabricated composites the Trypan-blue assay was also performed for PZM2 and PZM6 composites. Dissection on the gut of larvae was also performed on the both composites followed by DAPI and DCFH-DA staining. Therefore, these synthesized samples can be used for the fabrication of denture materials.

Fabrication, structural, and enhanced mechanical behavior of MgO substituted PMMA composites for dental applications.

The most common denture material used for dentistry is poly-methyl-methacrylate (PMMA). Usually, the polymeric PMMA material has numerous biological, mechanical and cost-effective shortcomings. Hence, to resolve such types of drawbacks, attempts have been made to investigate fillers of the PMMA like alumina (Al2O3), silica (SiO2), zirconia (ZrO2) etc. For the enhancement of the PMMA properties a suitable additive is required for its orthopedic applications. Herein, the main motive of this study was to synthesize a magnesium oxide (MgO) reinforced polymer-based hybrid nano-composites by using heat cure method with superior optical, biological and mechanical characteristics. For the structural and vibrational studies of the composites, XRD and FT-IR were carried out. Herein, the percentage of crystallinity for all the fabricated composites were also calculated and found to be 14.79-30.31. Various physical and optical parameters such as density, band gap, Urbach energy, cutoff energy, cutoff wavelength, steepness parameter, electron-phonon interaction, refractive index, and optical dielectric constant were also studied and their values are found to be in the range of 1.21-1.394 g/cm3, 5.44-5.48 eV, 0.167-0.027 eV, 5.68 eV, 218 nm, 0.156-0.962, 4.273-0.693, 1.937-1.932, and 3.752-3.731 respectively. To evaluate the mechanical properties like compressive strength, flexural strength, and fracture toughness of the composites a Universal Testing Machine (UTM) was used and their values were 60.3 and 101 MPa, 78 and 40.3 MPa, 5.85 and 9.8 MPa-m1/2 respectively. Tribological tests of the composites were also carried out. In order to check the toxicity, MTT assay was also carried out for the PM0 and PM15 [(x)MgO + (100 - x) (C5O2H8)n] (x = 0 and 15) composites. This study provides a comprehensive insight into the structural, physical, optical, and biological features of the fabricated PMMA-MgO composites, highlighting the potential of the PM15 composite with its enhanced density, mechanical strength, and excellent biocompatibility for denture applications.

Correction to: Bilateral Radial Head Fracture Secondary to Weighted Push-Up Exercise: Case Report and Review of Literature of a Rare Injury.

[This corrects the article DOI: 10.1007/s43465-021-00427-0.].

Bilateral Radial Head Fracture Secondary to Weighted Push-Up Exercise: Case Report and Review of Literature of a Rare Injury.

A 33-year-old male presented with bilateral radial head fractures after weighted prone push-up exercise. The patient had Mason type I and II on right and left sides, respectively. He was managed conservatively with limited immobilisation and early range of motion exercises. The fracture healed and patient had no complaints at the last follow-up of 13 months. Bilateral radial head fracture is rare with push-up exercise, and can be successfully treated conservatively with immobilisation and early rehabilitation. Although push-up exercises are an excellent workout with known benefits, unusual modifications of standard techniques should be avoided.

Is Flexion Gap Rectangular in Native Indian Knees? Results of an MRI Study.

BACKGROUND: The purpose of this study was to evaluate the flexion-gap of the native knees in the normal population and to assess any gender-specific variations in the flexion gap of the knees. METHODS: A total of 50 normal asymptomatic volunteers with normal knee radiographs were selected for MRI of the knee. The left knee was scanned in an open MRI using a T1-weighted sequence. Imaging was performed in neutral, passive varus and valgus stress at 90° of knee flexion by placing custom-made blocks on a special board consecutively below the distal part of the leg. RESULTS: The study population consisted of 26 males and 24 females with a mean age of 25.77 years. Under varus stress, the mean lateral flexion gap increased to 9.28 ± 1.53 mm and under valgus stress, the mean medial flexion gap increased to 2.75 ± 1.22 mm from neutral. The increase in the flexion gap on the lateral side was 5.28 ± 1.79 mm, which was significantly higher compared to that on the medial side. In gender-specific analysis, the mean lateral flexion gap was 10.21 mm in females and 8.46 mm in males under varus stress. CONCLUSION: The findings of the study indicate that the lateral soft tissues are more lax compared to the medial soft tissue structures and this laxity is higher in females as compared to males. The study provides evidence of the existing physiological variations of these soft tissue structures resulting in a trapezoidal flexion gap in the native knees rather than the recommended rectangular gap.

Plate Osteosynthesis or Figure-of-Eight Brace: Which One Is Better in Midshaft Clavicle Fractures?

Introduction Fracture of the clavicle bone is a very common injury owing to its subcutaneous location. Controversy exists about the optimal treatment of midshaft clavicle fractures in the presence of significant displacement and comminution of the fracture. Traditionally, non-surgical management was considered the first treatment option for most clavicle fractures. However, recent evidence shows that the non-surgical option causes more complications than previously reported. The purpose of this study was to compare the clinical and radiological outcomes of conservative treatment and surgical treatment for midshaft clavicle fractures. Materials and methods A total of 45 patients meeting the inclusion criteria were included in this randomized study. The patients were allocated to two groups: conservative and operative on an alternate basis. Patients in the conservative group were managed with figure-of-eight bandage, whereas patients in the operative group were treated surgically by plate fixation. Primary outcome was recorded at six weeks, three months, six months, and 12 months follow-up using the Disabilities of the Arm, Shoulder, and Hand (DASH) and American Shoulder and Elbow Surgeons (ASES) scores. We also assessed patient's satisfaction after the treatment, fracture union, and complication rates among the study cohort. Results The ASES scores were significantly better in the operative group at three months and six months follow-up; however, at 12 months follow-up, there was no significant difference in the score between the groups. Although not statistically significant, the DASH score was better in the operative group than in the conservative group at all the follow-ups. This study showed that the time to union was lesser, rate of non-union was lower, and return to work was faster on the operative group. The mean satisfaction score in the operative and conservative groups was 4.16±0.76 and 4.05±1.24, respectively (p = 0.76). Conclusion This study suggests that open reduction and internal fixation with plate reduced the incidence of mal-union and non-union; however, surgical treatment showed no significant difference in the functional outcome as compared to conservative treatment.

Bent Tibial Nail with Refracture: A Cost-Effective Removal Method: A Case Report.

CASE: A 45-year old man presented with a right open tibial fracture with a prominent, fixed deformity because of a retained right tibial intramedullary nail from a previous tibial fracture. After multiple futile intraoperative attempts to extract the bent nail, it was finally sectioned using an industrial drill bit that permitted its removal and revision tibial nailing. CONCLUSIONS: A tibial fracture resulting in a retained, bent nail presents unique challenges for nail extraction and subsequent exchange nailing. Failed implant removal can be limited by the equipment available in the operating theater. In this setting, the judicious use of inexpensive industrial materials and instruments may be effective in select cases.

A Large Posteromedial Parameniscal Cyst Masquerading a Baker's Cyst: An Unusual Presentation.

INTRODUCTION: Meniscal cysts are rare and strongly associated with a horizontal meniscal lesion. Arthroscopic partial meniscectomy of the meniscus with intra-articular cyst drainage has become the standard of care for small cyst; however, sometimes large cyst requires open excision. CASE PRESENTATION: We report a case of a large symptomatic medial parameniscal cyst in 52-year-old female which was clinically misdiagnosed as Baker's cyst. The patient had swelling over the posteromedial aspect of the right knee with difficulty and pain on squatting. Magnetic resonance imaging (MRI) reported horizontal tear in the posterior horn of medial meniscus and parameniscal cyst adjacent to medial meniscus with features of early osteoarthritis of the knee. She was successfully treated with open excision and repair of the defect of the cyst along with arthroscopic partial medial meniscectomy. CONCLUSION: This case highlights the importance of MRI in diagnosis and planning and the use of a combined approach for successful management of large parameniscal cyst.

Evaluating the Outcome of Two Different Regimes in Adhesive Capsulitis: A Prospective Clinical Study.

OBJECTIVE: Adhesive capsulitis or frozen shoulder is a painful condition affecting up to 5% of the general population. We conducted this study with the aim of evaluating the results of physiotherapy plus intra-articular methylprednisolone injection versus physiotherapy alone in idiopathic frozen shoulder. METHODS: This prospective clinical study was conducted in a tertiary care center between August 2016 and August 2018. Patients who were diagnosed with idiopathic frozen shoulder were included in the study, and each patient was randomly allocated to one of two groups: physiotherapy alone (group A) and physiotherapy plus intra-articular steroid injection (group B). RESULTS: A total of 52 cases diagnosed with idiopathic frozen shoulder were included and treated with the two modalities. There was a significant improvement in group B compared to group A at 6 weeks and 3 months in the range of flexion, abduction, and external rotation. The Shoulder Pain and Disability Index showed improvement in both pain and disability score in group B -compared to group A, and improvement was significant at 6 weeks and 3 months. CONCLUSION: The results demonstrate the advantages of physiotherapy plus intra-articular steroid injection in idiopathic frozen shoulder. The predictability of results with physiotherapy plus intra-articular steroid injection in selected patients is excellent, and it is a better modality of treatment compared to physiotherapy alone.

A Rare Case Report on Xanthogranulomatous Osteomyelitis of Hip Mimicking Tuberculosis and Review of Literature.

Xanthogranulomatous osteomyelitis (XO) is a rare chronic inflammatory process characterized by the presence of a large number of lipid-containing macrophages with lymphocytes and plasma cells. We present a case of XO of the hip in a 50-year-old woman with pain in the left hip for 28 months. The patient had a history of taking anti-tuberculosis chemotherapy for five months. Laboratory data revealed an increased erythrocyte sedimentation rate and C-reactive protein (CRP) level. Plain radiographs showed the destruction of the femoral head with arthritis and subluxation. Magnetic resonance imaging (MRI) was suggestive of tubercular infection of the left hip and a benign lesion in the left ilium. The histopathologic examination of the specimen demonstrated the presence of dead bone surrounded by lymph-plasma cells, foamy cells, and histocytes, which was consistent with XO, and culture was positive for Staphylococcus aureus infection. The patient was successfully treated with resection arthroplasty and antibiotics. It is important for the surgeons to keep XO in the list of differentials in cases with lytic lesions of bone and assessment should include microbiological culture along with the biopsy.

Do we really need to repair the pronator quadratus after distal radius plating?

PURPOSE: Fractures of distal radius are one of the common orthopaedic injuries. Placing the plate on volar surface requires release of underlying pronator quadratus (PQ) muscle. No consensus is present in the literature about the repair or not of the PQ. The purpose of this study was to evaluate the influence of PQ repair on functional outcome and complications. METHODS: Retrospectively 83 patients of distal radius fractures managed with volar plating between 2014 and 2016 were evaluated. Demographic data, operative notes and physical therapy records were retrieved. Patients were divided into group A where PQ repair was done and group B where no repair was done. Functional data such as range of motion (ROM), grip strength, visual analogue scale (VAS) score and disabilities of arm, shoulder and hand (DASH) score at 4 weeks, 3 months, 6 months and finial follow-up were retrieved. RESULTS: Totally 63 patients (n = 29 in group A and n = 34 in group B) with the mean age of 51.64 years were examined. Patients were followed up for a mean of 35.2 months (range 27.2-47.1 months) in group A and 38.6 months (range 28.6-51.0 months) in group B. Though functional outcome of the affected limb was not significantly different between two groups after 3 months, PQ repair did affect the recovery at an early stage. Repair group had significantly better ROM (p = 0.0383) and VAS score at 4 weeks (p = 0.017) while grip strength (p = 0.014) was significantly better at 3 months. CONCLUSIONS: Repair of PQ may provide pain relief and increased ROM in early postoperative period and hence every attempt should be made to achieve the repair.

Enhanced mechanical properties of hBN-ZrO2 composites and their biological activities on Drosophila melanogaster: synthesis and characterization.

In this study, six compositions in the system [x(h-BN)-(100 - x)ZrO2] (10 ≤ x ≤ 90) were synthesized by a bottom up approach, i.e., the solid-state reaction technique. XRD results showed the formation of a novel and main phase of zirconium oxynitrate ZrO(NO3)2 and SEM exhibited mixed morphology of layered and stacked h-BN nanosheets with ZrO2 grains. The composite sample 10 wt% h-BN + 90 wt% ZrO2 (10B90Z) showed outstanding mechanical properties for different parameters, i.e., density (3.12 g cm-3), Young's modulus (10.10 GPa), toughness (2.56 MJ m-3), and maximum mechanical strength (227.33 MPa). The current study further checked the in vivo toxicity of composite 10B90Z and composite 90B10Z using Drosophila melanogaster. The composite 10B90Z showed less cytotoxicity in this model, while the composite 90B10Z showed higher toxicity in terms of organ development as well as internal damage of the gut mostly at the lower concentrations of 1, 10, and 25 µg mL-1. Altogether, the current study proposes the composite 10B90Z as an ideal compound for applications in biomedical research. This composite 10B90Z displays remarkable mechanical and biological performances, due to which we recommend this composition for various biomedical applications.

Evaluation of practical framework for industrial noise mapping: A case study.

Strategic noise maps are typically prepared for large-scale areas, towns and cities. However, some comparatively smaller industries are given less importance during preparation of noise maps. Very few studies have been reported worldwide providing insight on industrial noise mapping, and similar reports from India are negligible. This study provides a noise map of a forging plant and also investigates noise distribution pattern within 2 km of surrounding area. The complete study is evaluated in two types of scenario; in the first scenario all individual noise sources of the plant were considered as point sources whereas in the second scenario complete plant was treated as an area source. Furthermore, a regression graph is generated between the predicted and measured values for both scenarios individually which gives coefficients of determination of 0.4689 and 0.6382. This study reveals that the second scenario provides more precise noise prediction map than the first scenario.

Realizing modeling and mapping tools to study the upsurge of noise pollution as a result of open-cast mining and transportation activities.

INTRODUCTION: In open-cast mines, noise pollution has become a serious concern due to the extreme use of heavy earth moving machinery (HEMM). MATERIALS AND METHODS: This study is focused to measure and assess the effects of the existing noise levels of major operational mines in the Keonjhar, Sundergadh, and Mayurbhanj districts of Odisha, India. The transportation noise levels were also considered in this study, which was predicted using the modified Federal Highway Administration (FHWA) model. RESULT AND DISCUSSION: It was observed that noise induced by HEMM such as rock breakers, jackhammers, dumpers, and excavators, blasting noise in the mining terrain, as well as associated transportation noise became a major source of annoyance to the habitants living in proximity to the mines. The noise produced by mechanized mining operations was observed between 74.3 and 115.2 dB(A), and its impact on residential areas was observed between 49.4 and 58.9 dB(A). In addition, the noise contour maps of sound level dispersion were demonstrated with the utilization of advanced noise prediction software tools for better understanding. CONCLUSION: Finally, the predicted values at residential zone and traffic noise are correlated with observed values, and the coefficient of determination, R2, was calculated to be 0.6891 and 0.5967, respectively.