Accuracy of Femoral Tunnel Placement between Anteromedial and Anterolateral Visualisation Portals in Anterior Cruciate Ligament Reconstruction - Outcomes of a CT based Cross-Sectional Study

Introduction

Anatomical femoral tunnel placement is critical for anterior cruciate ligament reconstruction (ACLR). Tunnel placement may vary with different surgical techniques. The aim of this study was to compare the accuracy of femoral tunnel placement between the Anteromedial (AM) and Anterolateral (AL) visualisation portals on post-operative CT scans among a cohort of ACLR patients.

Materials and methods

This cross-sectional study was conducted from January 2018 to March 2020 after obtaining ethics clearance. Patients who went for arthroscopic ACLR in our institute were divided into an AM (group 1) and an AL (group 2) based on the visualisation portal for creating the femoral tunnel and a 3D CT scan was done. The femoral tunnel position was calculated in deep to shallow and high to low direction using the Bernard Hertel grid. Femoral tunnel angle was measured in the 2D coronal image. Statistical analysis was done with the data collected.

Results

Fifty patients with an average age of 26.36 (18-55) years ±7.216 SD were enrolled in the study. In this study, the AM technique was significantly more accurate (p<0.01) than the AL technique in terms of femoral tunnel angle. Furthermore, the deep to the shallow position was significantly (p= 0.018) closer to normative values, as determined by the chi-square test. The chances of error in tunnel angle in femoral condyle are 2.6 times greater in the AL technique (minimal clinical difference).

Conclusion

To conclude, in ACLR the anteromedial visualisation portal can facilitate accurate femoral tunnel placement compared to the anterolateral visualisation portal.

Comparative analysis of the diagnostic performance of five commercial COVID-19 qRT PCR kits used in India

To meet the unprecedented requirement of diagnostic testing for SARS-CoV-2, a large number of diagnostic kits were authorized by concerned authorities for diagnostic use within a short period of time during the initial phases of the ongoing pandemic. We undertook this study to evaluate the inter-test agreement and other key operational features of 5 such commercial kits that have been extensively used in India for routine diagnostic testing for COVID-19. The five commercial kits were evaluated, using a panel of positive and negative respiratory samples, considering the kit provided by National Institute of Virology, Indian Council of Medical Research (2019-nCoV Kit) as the reference. The positive panel comprised of individuals who fulfilled the 3 criteria of being clinically symptomatic, having history of contact with diagnosed cases and testing positive in the reference kit. The negative panel included both healthy and disease controls, the latter being drawn from individuals diagnosed with other respiratory viral infections. The same protocol of sample collection, same RNA extraction kit and same RT-PCR instrument were used for all the kits. Clinical samples were collected from a panel of 92 cases and 60 control patients, who fulfilled our inclusion criteria. The control group included equal number of healthy individuals and patients infected with other respiratory viruses (n = 30, in each group). We observed varying sensitivity and specificity among the evaluated kits, with LabGun COVID-19 RT-PCR kit showing the highest sensitivity and specificity (94% and 100% respectively), followed by TaqPath COVID-19 Combo and Allplex 2019-nCoV assays. The extent of inter-test agreement was not associated with viral loads of the samples. Poor correlation was observed between Ct values of the same genes amplified using different kits. Our findings reveal the presence of wide heterogeneity and sub-optimal inter-test agreement in the diagnostic performance of the evaluated kits and hint at the need of adopting stringent standards for fulfilling the quality assurance requirements of the COVID-19 diagnostic process.

Clinico-microbiological spectrum of anaerobic pyogenic infections in an Indian tertiary care teaching hospital: A two-year study

Introduction:

Anaerobes are important however the most neglected pathogens. Timely isolation of anaerobes can guide the clinician about the correct course of clinical treatment and thus reduce the mortality and also the problem of antimicrobial resistance.

Materials and Methods:

Tissue and/or pus aspirates were collected aseptically from infectious sites in the Robertson's cooked meat medium (RCM) and sent to anaerobic bacteriology laboratory for culture. Subcultures from RCM for each sample were done on neomycin blood agar and 5% sheep blood agar along with metronidazole disc (5μg). The plates were incubated in an anaerobic jar using GasPak for 72 hrs. The preliminary identification was performed by standard biochemical tests for both obligate and facultative anaerobic isolates. Speciations of obligate anaerobes were performed by Vitek 2 automated system.

Results:

Obligate anaerobes either single or polymicrobial were obtained in 38/216 (14.5 %) samples processed during the study period. Polymicrobial infections were reported in 21/216 (55.26%) samples and most commonly with obligate anaerobic gramnegative bacilli i.e. Prevotella-Porphyromonas and Bacteroides fragilis group. Most common monomicrobial anaerobic infections were observed with Veillonella spp. (n=4) and Porphyromonas spp. (n=4) followed by Bacteroides fragilis (n=3). Obligate anaerobes were predominantly isolated from skin and soft tissue infections (n=14) followed by surgical site infections (n=8).

Conclusion:

Although most of the infections are polymicrobial, a rise in the incidence of monomicrobial anaerobic infections has been noticed. Therefore, the performance of anaerobic cultures along with aerobic cultures is much needed for complete bacterial work-up of specimens from infectious sites and better patient management.

Predictors of Functional Outcome in Unstable Ankle Fractures Treated Surgically - A Prospective Cohort Study

Introduction:

Unstable ankle injuries require anatomical reduction and stabilisation for optimal outcome. In spite of adequate care, a few patients have poor outcome. In this study, we assessed the risk factors that predict the clinical outcomes in surgically treated unstable ankle fractures.

Material and methods:

This prospective cohort study was conducted on 68 patients who underwent surgical management for an unstable ankle injury. Demographic details, fracture type and associated medical comorbidities were recorded. Pre-operative radiographic assessment was done for all patients. At the end of one year follow-up, clinical (American Orthopaedic foot and ankle society-AOFAS and Olerud-Molander ankle - OMAS) scores and radiological parameters were assessed and analysed.

Results:

Fracture dislocation (0.008), diabetes mellitus (0.017), level of alchohol consumption (0.008) and pre-operative talocrural angle (TCA) > 100° (0.03) were significant predictors of poor outcomes as per AOFAS. Fracture dislocation (0.029), diabetes mellitus (0.004), pre-operative TCA > 100° (0.009), female gender (0.001), age more than 60 years (0.002) and open injuries (0.034) had significantly poor outcome as per OMAS. Other parameters (smoking, hypertension, classification, syndesmotic injury, medial clear space and tibiofibular overlap) did not affect the outcome significantly.

Conclusion:

Our study showed that poor outcome predictors in unstable ankle fractures are age >60 years, female gender, diabetes mellitus, alcohol consumption, fracture dislocation, open fractures and pre-op TCA >100°.

Solitary Osteochondroma of the Tibial Tuberosity Mimicking Osgood-Schlatter Lesion: A Rare Cause of Anterior Knee Pain in Adolescents: A Case Report

Osteochondroma arising from the tibial tuberosity is very rare. We report such a case which mimicked OsgoodSchlatter's disease in an adolescent. A 12 years-old boy presented with swelling over his right proximal tibia of one year duration associated with pain in the last three months. Examination revealed a 4 x 2cm bony mass arising from the proximal tibia. Radiographs revealed an osteochondroma of the tibial tuberosity. Computer tomography and magnetic resonance imaging confirmed the continuity of the medulla of the bony mass to that of the parent bone. Excision biopsy was done. At the final follow up, he was asymptomatic and returned back to his daily activities. We present this case for its rarity, challenges involved in diagnosis and the difficulties encountered in planning the surgery because of involvement of the apophysis and extensor mechanism attachment in a skeletally immature boy.

Study of HIV-1 subtypes in serodiscordant couples attending an integrated counselling and testing centre in Mumbai using heteroduplex mobility analysis and DNA sequencing

AIMS

To determine the prevalent subtypes of HIV-1 in serodiscordant couples.

SETTING

Integrated Counselling and Testing Centre (ICTC), Department of Microbiology.

STUDY DESIGN

Prospective pilot study.

PARTICIPANTS

Thirty HIV-1 serodiscordant couples.

INCLUSION CRITERIA

a) Documentation of HIV-1 infection in one partner and seronegative status in the other, current history of continued unprotected sexual activity within the partnership, demonstration that they have been in a partnership for at least 1 year and are not currently on highly active antiretroviral therapy HAART; b) willingness of both partners to provide written informed consent including consent to continued couple counselling for 3 months.

MATERIALS AND METHODS

HIV-1 subtyping was carried out by heteroduplex mobility analysis (HMA) by amplifying env region; and DNA sequencing by amplifying gag region.

RESULTS

HIV-1 env gene was amplified successfully in 10/30 samples; gag gene, in 25/30 samples; and both env and gag gene were amplified successfully in 5/30 samples. HIV-1 subtype C was detected from 21 samples; subtype B, from 7; and subtype A, from 2. Sample from 1 positive partner was detected as subtype C by env HMA and subtype B by gag sequencing.

CONCLUSION

HIV-1 subtype C was found to be the predominant subtype of HIV-1 in serodiscordant couples attending our ICTC, followed by HIV-1 subtype B and HIV-1 subtype A, respectively. DNA sequencing was found to be the most reliable method for determining the subtypes of HIV-1.

Stability of reconstituted parecoxib for injection with commonly used diluents

OBJECTIVE

The purpose of this study was to evaluate the effect of diluent type, storage conditions and the nature of package on the stability of reconstituted Parecoxib sodium for injection (PSI).

METHODS

Parecoxib sodium for injection is a lyophilized product for single use. It is intended for the management of acute pain. Six diluent types were initially evaluated for physical compatibility with PSI. Reconstituted PSI was visually inspected at 8, 24 and 48 h after reconstitution with 0.9% sodium chloride injection (NS), lactated ringers injection (LR), bacteriostatic 0.9% NaCl injection (BNS), lactated ringers and 5% dextrose injection (LR + D5W), 5% dextrose injection (D5W), and 5% dextrose + 0.45% NaCl injection (D5W + 1/2NS). Reconstituted PSI, stored in glass vials and glass or plastic syringes at 5 degrees and 25 degrees C, under 500 lx light intensity for 48 h or subjected to freeze-thaw cycles, were tested for chemical stability by high-performance liquid chromatography (HPLC).

RESULTS

The PSI reconstituted with NS, BNS, D5W, and D5W + 1/2NS met visual acceptance criteria and showed almost no (<0.5% total) degradation under all storage conditions. No significant differences were seen between storage in glass vials or polypropylene/glass syringes. PSI reconstituted with LR and LR + D5W showed visual precipitation in many vials which was confirmed by the decrease in the HPLC assay values at all time points. The needlelike crystals (precipitate), analyzed by Infrared Spectroscopy and Scanning Electron Microscopy-Energy Dispersive Spectrometry (SEM-EDS) analyses, were identified as the free acid form of the active drug.

CONCLUSION

PSI is stable after reconstitution, with NS, BNS, D5W, and D5W + 1/2NS, when stored at room temperature in glass vials or glass/plastic syringes for up to 48 h* LR and LR + D5W are not recommended for reconstitution because of crystallization of the drug (free acid).

Emerging bacterial drug resistance in hospital practice

The growing multiple drug resistance among bacteria in hospital practice is posing a serious threat to the successful antimicrobial therapy. Our data on the bacterial drug resistance at a tertiary care centre during 1995-1996 has been alarming with an incidence of 73 to 99% resistance to the common antibiotics like ampicillin, chloramphenicol, cotrimoxazole and first generation cephalosporins among the gram negative isolates. The resistance to gentamicin and ciprofloxacin ranged from 53 to 79%. Resistance to amikacin, netilmicin and the third generation cephalosporins ranged from 30 to 73%. The frightening observation was the emergence of resistant isolates which were sensitive only to two drugs, sensitive only to one drug and resistant to all the available antibiotics (2.64, 17.6 and 11.5% respectively) during 1994 to 1996. Resistance among the gram positive bacteria was much less but the increase in methicillin resistant Staphylococci (52-65%) was a serious matter. The data were an eye opener and the infection control measures could bring marginal improvement in the situation in 1996. It is vehemently appealed that the national antibiotic policies be formed and be stringently implemented before we are thrown back to the pre-antibiotic era.

Excipients and their use in injectable products

Formulation of a new drug product with excipients, that have been previously added to an approved injectable product, may save pharmaceutical companies developmental time and cost. The Physicians' Desk Reference (PDR) and Handbook on Injectable Drugs were reviewed, extracting all information on excipients. The information was consolidated into eight tables, categorizing excipients as 1) Solvents and Co-solvents, 2) Solubilizing, Wetting, Suspending, Emulsifying or Thickening agents, 3) Chelating Agents, 4) Antioxidants and Reducing Agents. 5) Antimicrobial Preservatives, 6) Buffers and pH Adjusting Agents, 7) Bulking Agents, Protectants, and Tonicity Adjustors, and 8) Special Additives. Where applicable, tables list frequency of use, concentration, and an example of a commercial product containing the excipient. Excipients which are included in the 1996 FDA 'Inactive Ingredient Guide,' but do not appear in the PDR or Handbook on Injectable Drugs, were included as a separate list.

Antibiogram study over bacterial isolates from cases of bacteraemias

During January, 1994 to December, 1994, 703 of the 1778 blood specimen were positive for blood culture and 59.9% of the isolates were of staphylococci. Thirty two percent of the staphylococci were methicillin resistant. Netilmycin showed the lowest in vitro resistance among Gram positive cocci & Klebsiella species. Netilmycin, amikacin, ciprafloxacin and the third generation cephalosporins in general showed greater in vitro sensitivity among gram negative bacilli. The netilmycin had the lowest incidence of drug resistance based on the pooled data over the blood culture.

Protection of a model protein, lactate dehydrogenase by encapsulation in liposome

The objective of this study was to determine if encapsulating a model protein, lactate dehydrogenase (LDH), inside liposomes can protect it during storage, upon freeze-thaw cycles and during freeze-drying. LDH, which undergoes cold denaturation, was entrapped insides liposomes prepared using modification of Bangham's method. It was found that when LDH was entrapped in liposomes and subjected to a single freeze-thaw treatment, there was about 7 times more recovery of activity than when LDH was free in solution. Similarly, LDH encapsulated in liposomes showed 60% recovery after freeze-drying compared to 1-2% recovery for the unentrapped LDH. The role of phospholipid content, residual moisture content and protein content were evaluated. Possible mechanism(s) of cold temperature inactivation of proteins and role of liposomes in preventing such cryodenaturation will be discussed in light of these results.

Protection of lactate dehydrogenase against protease digestion by encapsulation in liposomes

Lactate dehydrogenase (LDH) was entrapped in phosphatidylcholine liposomes to evaluate the protective effect of liposomes against protease digestion. Three different preparations of LDH either encapsulated in liposomes, unencapsulated in liposomes or in the absence of liposomes were incubated with the protease trypsin. The loss of LDH activity was measured at intervals over a 12-hour period. The degradation rate of LDH was found to be the same when LDH was unencapsulated in the presence or absence of liposomes. However, when LDH was entrapped in liposomes the degradation rate was 4 to 24 folds slower. This finding indicates that encapsulation of a protein in a liposome protects the protein from the degrading effects of a protease enzyme.

Freeze-thaw studies of a model protein, lactate dehydrogenase, in the presence of cryoprotectants

The objective of this study was to investigate the behavior of lactate dehydrogenase (LDH) upon freezing and thawing, alone or in the presence of several selected cryoprotectants. Also, the influence of the freezing rate on retainment of LDH activity was investigated. It was observed that fast freezing caused less loss of LDH activity than slow freezing. The probable mechanisms of loss of activity after freeze-thaw cycles were discussed. Selected cryoprotectants were evaluated for their ability to protect LDH during freeze-thaw cycles. Surface tension and pH change measurements upon freezing of the cryoprotectant solutions were carried out. Based on the results of these experiments, a potential mechanism of cryoprotection has been developed.

Loss of LDH activity during membrane filtration

Membrane filters rendered hydrophilic and composed of biphenyl polycarbonate, polyvinylidene fluoride (PVDF), acrylic copolymer, polysulfone, and mixed esters of cellulose were evaluated to determine which type of filter best can be used for the filtration of lactate dehydrogenase (LDH) solution. Also, the effect of the membrane pore size was evaluated. LDH solution was passed through the filters at a controlled flow rate, after which the filtrate was assayed for LDH activity and protein content using the Bradford method. Polycarbonate and PVDF filters generally showed low loss of protein, except 5 microns PVDF filters. Mixed esters of cellulose, acrylic copolymer, and polysulfone caused considerable loss of protein during passage of the LDH solution through the filter. Interestingly, it was also found that, generally, as the pore size increased the amount of protein loss decreased. However, 5 microns PVDF and mixed esters of cellulose filters showed more loss than their corresponding 0.65 microns and 3 microns pore size filters, respectively. In all cases, more protein was recovered in the filtrate fractions as the volume of LDH solution filtered was increased, suggesting that the mechanism of loss is adsorption and that the magnitude of loss is related to saturation of the matrix polymer surfaces.