Walking speeds are lower for short distance and turning locomotion: Experiments and modeling in low-cost prosthesis users.

Preferred walking speed is a widely-used performance measure for people with mobility issues, but is usually measured in straight line walking for fixed distances or durations, and without explicitly accounting for turning. However, daily walking involves walking for bouts of different distances and walking with turning, with prior studies showing that short bouts with at most 10 steps could be 40% of all bouts and turning steps could be 8-50% of all steps. Here, we studied walking in a straight line for short distances (4 m to 23 m) and walking in circles (1 m to 3 m turning radii) in people with transtibial amputation or transfemoral amputation using a passive ankle-foot prosthesis (Jaipur Foot). We found that the study participants' preferred walking speeds are lower for shorter straight-line walking distances and lower for circles of smaller radii, which is analogous to earlier results in subjects without amputation. Using inverse optimization, we estimated the cost of changing speeds and turning such that the observed preferred walking speeds in our experiments minimizes the total cost of walking. The inferred costs of changing speeds and turning were larger for subjects with amputation compared to subjects without amputation in a previous study, specifically, being 4x to 8x larger for the turning cost and being highest for subjects with transfemoral amputation. Such high costs inferred by inverse optimization could potentially include non-energetic costs such as due to joint or interfacial stress or stability concerns, as inverse optimization cannot distinguish such terms from true metabolic cost. These experimental findings and models capturing the experimental trends could inform prosthesis design and rehabilitation therapy to better assist changing speeds and turning tasks. Further, measuring the preferred speed for a range of distances and radii could be a more comprehensive subject-specific measure of walking performance than commonly used straight line walking metrics.

Automated Closed-Loop Propofol Anesthesia Versus Desflurane Inhalation Anesthesia in Obese Patients Undergoing Bariatric Surgery: A Comparative Randomized Analysis of Recovery Profile.

INTRODUCTION: Precision general anesthesia (GA) techniques that minimize the presence of residual anesthetic and facilitate recovery, are desirable in patients with morbid obesity. Automated administration of propofol total intravenous anesthesia (TIVA), which facilitates precision propofol delivery by factoring in continuous patient input variable (bispectral index) to establish a closed feedback loop system, may help mitigate concerns related to propofol's lipid solubility and adverse accumulation kinetics in patients with morbid obesity. This randomized study evaluated the recovery of patients with morbid obesity undergoing bariatric surgery under propofol TIVA automated by a closed-loop anesthesia delivery system (CLADS) versus desflurane GA. METHODS: Forty patients, randomly allocated to receive propofol TIVA (CLADS group) or desflurane GA (desflurane group), were evaluated for postoperative recovery (early and intermediate) (primary objective); they were evaluated for intraoperative hemodynamics, anesthesia depth consistency, anesthesia delivery performance characteristics, patient satisfaction, and incidence of adverse events (sedation, pain, postoperative nausea, and vomiting) (secondary objective). RESULTS: No difference was found for the time-to-eye-opening (CLADS group: 4.7 [3.0, 6.7] min vs. desflurane group: 5.6 [4.0, 6.9] min, P = 0.576), time-to-tracheal-extubation (CLADS group: 6.7 [4.7, 9.3] min vs. desflurane group: 7.0 [5.8, 9.2] min, P = 0.528), ability-to-shift score from operating room table to the transport bed (CLADS group: 3 [3.0, 3.5] vs. desflurane group: 3 [3.0, 4.0], P = 0.703), and time to achieve a modified Aldrete score 9/10 (CLADS group: 15 [15.0, 37.5] min vs. desflurane group: 15 [15.0, 43.7] min, P = 0.867). CONCLUSION: Automated propofol TIVA as administered by CLADS, which matched desflurane GA with respect to depth of anesthesia consistency and postanesthesia recovery profile, can be explored further as an alternative anesthesia technique in patients with morbid obesity.

Contemporary challenges in clubfoot treatment: A quantitative study among Indian parents.

Purpose: The studies conducted a decade ago showed that the Ponseti method, suffers from many execution-related issues-particularly in low and middle-income countries including poverty, physical distance, lack of transportation etc. The society has undergone many changes, including improvements in literacy, connectivity (both transport and digital), etc., in the last decade. Therefore, this study is designed to identify the contemporary apprehensions, concerns, and challenges of parents seeking CTEV treatment for their child through the Ponseti Method in India. Methods: A descriptive cross-sectional study of 200 parents of the children undergoing treatment at a multi-specialty hospital is carried out using an interview guide. The semi-structured interviews were conducted telephonically and recorded. Results: The statistical analysis shows that a male child is presented late than a female child. The physical distance is associated with child discomfort during the casting and bracing phase, with the travel method affecting the follow-up. The increase in travel time may result in increased casts due to a lack of regular follow-up. Parents' income level is also strongly associated with regularity of follow-up and child discomfort during treatment. Conclusions: The patients traveling long distances in public transport are the most vulnerable group regardless of gender. The children in such cases are more likely to experience discomfort during the casting and bracing phase with a lack of regular follow-up. Expert doctors and brace unavailability in the local area remain vital challenges for the parents.

Study of Cell Viability and Etiology of Contamination in Decalcified Bone Allograft: A Pilot Study.

BACKGROUND: Bone allografts can elicit immune responses which is correlated with the presence of Human Leukocyte Antigen (HLA) and cellular DNA. It also has risk of causing occult infection arising out of contamination during its processing and storage. The presence of immunogenic materials like cells, cellular remnants and DNA in a decalcified bone allograft during different phases of processing has never been studied. Present study was conducted to explore- the cell viability using routine Hematoxylin and Eosin, presence of DNA using Feulgen staining and etiology of contamination in decalcified bone allograft during procurement, demineralization and ethanol preservation. METHODS: The harvested bones from patients undergoing hemireplacement/THR/TKR were processed to prepare decalcified bone allografts. The samples during procurement (A), HCL treatment (B) and ethanol preservation (C) were sent for histopathological analysis (number of osteocytes in the maximum density field under 40x and the cells demonstrating presence of DNA on feulgen stain) and microbiological assessment (aerobic/anaerobic/fungal cultures). RESULTS: Histopathological study demonstrated the presence of osteocytes and other cells like bone marrow, adipocytes, endothelial cells in the decal bone allograft. The average number of osteocytes gradually decreased from 55.47, 9.6, 0.86 in sample A, B, C, respectively. Feulgen staining confirmed the presence of DNA in osteocytes and other cells which decreased both qualitatively and quantitatively in subsequent stages of processing. Rate of contamination demonstrated at the procurement was 6.67% (Staphylococcus aureus). After treatment with HCl (demineralisation), 7.14% of non-contaminated allografts were found contaminated (Staphylococcus epidermidis). None of the remaining 13 non-contaminated allografts showed contamination after storage in ethanol. Overall 13% of the patients had positive cultures on microbiological assessment. CONCLUSION: The population of osteocytes in the harvested bone reduced significantly after processing with HCl and ethanol preservation. Presence of DNA, demonstrated by using Feulgen staining, was observed in bone marrow cells, adipocytes along with osteocytes which showed quantitative reduction on processing. Hence, antigenicity, conferred by cells and their DNA, reduced significantly after processing of decal bone. Contamination rate of banked decalcified allograft was 13%. Thus, culture and sensitivity tests should be carried out at each step of processing of decal bone allograft.

Evaluation of Hearing Loss in Congenital Hypothyroid Children at a Tertiary Care Hospital in Central India.

Hearing loss has long been associated with congenital hypothyroidism and, if not noticed and treated early, may result in delayed language acquisition and difficulties in comprehension. In light of the implications of congenital hypothyroidism and its associated hearing loss, we decided to conduct this study. The aim of this study was to identify the prevalence of hearing loss in congenital hypothyroidism and its relation to the severity of the disease and age of initiation of treatment. This study was conducted from July 2016 to June 2021 at a tertiary care hospital in Bhopal. The hearing status of congenital hypothyroid children and matched controls was assessed by pure tone audiometry or free field audiometry and, in selected cases, with brainstem evoked response audiometry. Eight children (25%) with congenital hypothyroidism had hearing loss, compared to one (3.12%) in the control group (p < 0.05). No statistically significant difference has been found in the gender, mean age of diagnosis, mean age of initiation of levothyroxine treatment, mean screening FT4 levels, and mean screening TSH levels between congenital hypothyroid children with and without hearing loss. Due to the high prevalence of hearing loss in congenital hypothyroidism and its impact on language and cognitive development, it is critical to create awareness among healthcare professionals that children diagnosed with congenital hypothyroidism must undergo audiological evaluation at the time of diagnosis and periodically thereafter. Alternatively, children with unexplained hearing loss must be screened for congenital hypothyroidism.

Covid-19 Pandemic: Resumption of Orthopedic Care and Medical Education.

Covid-19 is a respiratory disease caused by coronavirus 2 (SARS-CoV-2) first identified in Wuhan, China (December 2019). The disease rapidly crossed the barrier of countries, continents and spread globally. Non-pharmaceutical measures such as social distancing, face mask, frequent hand washing and use of sanitizer remained the best available option to prevent the spread of disease. OPD, IPD admissions, elective O. Ts were curtailed. Orthopedic care was only limited to emergency and semi-urgent procedures like necrotizing fasciitis, open fracture, and compartment syndrome. These measures were taken to preserve infrastructure and manpower to manage covid-19 pandemic. The children were thought to have a low susceptibility to covid-19 as compared to an adult. Deferring the patient during pandemic has led to high orthopedic disease burden, morbidity and disease-related sequelae, hence elective care must be resumed with modified hospital infrastructure. Resumption of elective/emergent orthopedic care should be slow, phasic and strategic, much similar to unlocking. Cases must be stratified depending on covid status and severity. Dedicated O.Ts with neutral/negative pressure and HEPA filter for covid positive and suspected patients are to be used. All symptomatic and suspected patients should be investigated for covid-19 by RT-PCR, blood counts and CT scan. Regional anaesthesia should be preferred to General anaesthesia. Power drill/saw/burr/pulse lavage should be minimized to avoid aerosol generation. Postoperatively continuous surveillance and monitoring to be done for covid related symptoms. Medical institutes rapidly shifted to the online mode of education. Blended learning (virtual & physical) and imparting skills have to be continued in post covid phase with equitable distribution of teaching hours to students of different years.

Osteochondroma of the talus: three varying cases.

Osteochondroma of the talus is a rare entity that can cause pain, swelling, restriction of movements, synovitis and tarsal tunnel syndrome (TTS). We present three such cases with varying presentation. Case 1 presented with synovitis of the ankle along with a bifocal origin of the talar osteochondroma. Case 2 presented with TTS as a result of compression of the posterior tibial nerve. Case 3 presented with deformity of the foot. In all the three cases, the mass was excised en bloc and histologically proven to be osteochondroma. In case 3, the ankle joint was reconstructed with plate, bone graft and arthrodesis of the inferior tibiofibular joint. All the three cases had good clinical outcomes.

Conventional Tracheostomy Versus Percutaneous Tracheostomy: A Retrospective Study.

Objectives Emergency Tracheostomy is a life saving surgical procedure. With the advent of newer instruments and equipments in the critical care units, there is marked improvement in the quality of care of the critically ill patients and such patients are able to survive for a longer period. Elective tracheostomy is being done in those patients who needs positive pressure ventilation, for a longer duration. Objectives of our study are to compare conventional tracheostomy (CT) to percutaneous tracheostomy (PcT) and to identify the strategy with the lowest frequency of potentially life threatening events. Study Design Retrospective comparative study. Patients Included 30 patients who met inclusion criteria. Study Settings Tertiary care centre (medical college). Results 15 patients underwent CT and 15 underwent PcT. Blood loss, mean operation time and complications were compared. Blood loss and operation time was lesser in CT compared to PcT. There were no reported complications in both the techniques. Conclusion In our study CT took lesser time with lesser blood loss and without any complications. But statistically, this difference was not significant. Thus person with refined skill in the technique is of utmost importance in deciding the choice of a technique.

Microscopic Versus Endoscopic Myringoplasty: A comparative study.

To compare the results of myringoplasty by using operating microscope (postaural) with that of myringoplasty by using endoscope (permeatal). Our study was conducted in Department of ENT of in Chirayu Medical College and Hospital. Total 60 patients of age group 18-60 were taken for study having chronic otitis media or trauma with central perforation. Patients were randomly selected microscopic or endoscopic myringoplasty. 30 patients for Microscopic Myringoplasty and 30 patients for endoscopic Myringoplasty were selected. Out of total 60 patients 35 were females and the 25 were males, 27 were in the age group 15-30 and 23 were in age group 31-45 and only 10 in the age group of 46-60. 18-30 age group cohort was predominant. The average time taken for endoscopic myringoplasty was 65.5 ± 3.45 min and for microscopic myringoplasty 85.7 ± 3.42 min. 26 were having Large central perforation (LCP), of which 13 underwent microscopic and 13 underwent endoscopic myringoplasty. The graft was taken up in situ in 22 patients while 4 patients had small residual central perforation. Out of these four residual perforations 3 were done by endoscopy and 1 by microscopy. 19 (of 60) were having Medium size central perforation (MCP), 10 were operated with endoscope and 9 with microscope. 15 (60) were having Small central perforation (SCP), 7 done with endoscope and 8 with microscope. In all patient graft take up was well. Large central perforation present in maximum patient and had least graft uptake as compared to MCP and SCP. Out of the 30 these endoscopic myringoplasty 27 patients had good graft uptake and 3 had small central residual perforation after 3 months. Out of the 30 microscopic myringoplasty 29 patients had good graft uptake and 1 patient had small central residual perforation after 3 months. In our study pre operative and post operative Air Bone Gaps (ABGs) were 22.05 ± 2.04 and 9.05 ± 1.36 db respectively in endoscopic myringoplasty and 21.81 ± 1.85 and 8.55 ± 1.44 db respectively in microscopic myringoplasty. Microscopic myringoplasty has greater success rate in larger perforations that is LCP and MCP and equal result in SCP. Advantage of microscope is depth perception and both hands are free for procedure which is limitation of endoscopic myringoplasty (need to use endoscope holder). Advantage of endoscopic permeatal myringoplasty is superior visualization, least tissue trauma and better cosmetic outcome, almost equal graft uptake and hearing outcome with less operative time. Endoscope system is portable, so convenient for surgeon where microscope is not available. Also endoscope is a less costly armamentarium. Our study shows better result in myringoplasty can be achieved if both methods of surgery are used in combination.

Randomised Controlled Clinical Study of Injection Caroverine and Ginkgo Biloba Extract in Cochlear Synaptic Tinnitus.

Tinnitus, also known as phantom auditory perception, is an annoying symptom and 13-17% of population reports bothersome tinnitus. Cochlear synaptic tinnitus is the most common type. Many treatments have been tried but none is yet considered to be well established. To evaluate effect of Inj.Caroverine and Ginkgo Biloba extract in cochlear synaptic tinnitus in terms of improving tinnitus grading, tinnitus matching and quality of life of patient. It is Randomised controlled study, conducted in department of ENT, on 86 patients, who met inclusion criteria, divided into 4 groups. Gr1-Inj Caroverin, Gr2-Inj Placebo, Gr3-Ginkgo Biloba extract, Gr4-Placebo as extract. A single dose infusion of caroverine immediately improves tinnitus grading and matching and provides immediate relief in reducing severity of tinnitus in 54.54% cases but improvement was not sustained in caroverine group at 3 month and 6 month follow-up after infusion. Ginkgo biloba also is effective in improving tinnitus grading and matching in 31.8% cases and improvement was sustained in ginkgo biloba group even after 3 month of cessation of treatment i.e. at 6 month follow-up. It is suggested that Inj.Caroverine as intravenous infusion should be given in severe cases of tinnitus to reduce its severity immediately and then patient should be put on Tab.Ginkgo biloba for a period of 3 months to provide sustained and long lasting relief. Thus combination therapy of Inj.Caroverin and Tab.Ginkgo Biloba, appropriately tailored to the need of patient will provide better results in greater majority of patients.

Teaching Ear Examination Skill to Undergraduate Students Using Check List.

For examination of ear, proper illumination is a pre requisite. Diseases related to ear may lead to altered sense of hearing and may affect normal balance system. If students are taught to examine ear using a check list, they may perform better. To teach ear examination to undergraduate students using a check list. Total 50 undergraduate students of M.B.B.S. attending E.N.T. clinic in Chirayu Medical College and Hospital were included in the study. They were given enrolment no. 1 to 50 and were divided into two groups. Group 1, enroll. no. 1 to 25 and group 2, enroll. no. 26 to 50. Group 1 was taught using check list and the Group 2 was taught without use of checklist. Both the groups were evaluated using check list. The group B students were again taught, using check list and were again evaluated using check list. Use of check list showed that there was statistically significant improvement in learning by students using check list in group 1 students compared to group 2 students who were taught without use of check list. The group 2 students also had improvement on evaluation, after they were taught using check list. Study suggests that use of check list for ear examination skill to undergraduate students has significant role and students learn better than when taught without use of checklist. Inclusion of checklist for teaching ear examination to undergraduate students may be considered.

Efficacy of local wound infiltration analgesia with ropivacaine and dexmedetomidine in tubercular spine surgery - A pilot randomised double-blind controlled trial.

BACKGROUND AND AIMS: Regional analgesic techniques are difficult to use in tubercular spine patients due to distorted spinal anatomy and presence of infection. This study was conducted with the aim to evaluate analgesic efficacy of local wound infiltration before wound closure in tubercular spine patients. METHODS: This pilot randomised double-blind controlled study was conducted in 32 American Society of Anesthesiologists I-III patients, age ≥15 years, undergoing elective surgery for spinal tuberculosis. All the patients received general anaesthesia using standard technique and intravenous morphine for intraoperative analgesia. They received wound infiltration with either normal saline (group C) or local infiltration analgesia with 0.375% ropivacaine 3 mg/kg, adrenaline 5 µg/mL and dexmedetomidine 1 µg/kg in a total volume of 0.8 mL/kg (group LIA) before wound closure. Patient-controlled analgesia using intravenous morphine provided postoperative analgesia. The primary objective was to study 24-h morphine consumption, whereas the secondary objectives included pain scores, complications and patient satisfaction. Repeated measures analysis of variance, Chi-square test and Mann-Whitney U test were used for statistical analysis. RESULTS: Morphine requirement was lower in group LIA (6.7 ± 2.7 mg) than in group C (27.7 ± 7.9 mg);P < 0.001. Group LIA also had lower pain scores (P < 0.001), longer time to rescue analgesic (P < 0.001), better patient satisfaction to pain relief (P = 0.001) and lower incidence of postoperative nausea and vomiting than group C. CONCLUSION: Wound infiltration with ropivacaine, adrenaline and dexmedetomidine before wound closure provided good postoperative analgesia with lower morphine requirement.

Hypoglossal Nerve Palsy as a Rare Complication of C1-C2 Pott's Spine.

Reporting a rare scenario of hypoglossal nerve palsy in craniovertebral tuberculosis. Two patients presented in outpatient department with chief complaints of pain in neck, restricted neck movements, gait changes, difficulty in speech and weakness in all the extremities. On the basis of clinicoradiological correlation, the patients were diagnosedwithtuberculosis of C1-C2 spine. They were started on antituberculosis therapy Category 1. The patients improved clinically and there was no worsening of symptoms, but they noticed tongue deviation and hypotrophy on one side of the tongue. C1-C2 tuberculosis along with cranial nerve palsy, especially hypoglossal nerve is one of the rarest presentations. Hypoglossal nerve arises from the medulla, exits through hypoglossal canal in the base of the skull and traverses neck to supply tongue musculature. Prevertebral fascia extends from superior mediastinum to base of the skull. Abscess in this area can cause either actual compression of the hypoglossal canal or C1 and base of the skull dissociation which can lead to compression of the canal.

Prevalence of allergic bronchopulmonary aspergillosis in asthmatic patients: A prospective institutional study.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is characterized by an allergic inflammatory response to colonization by Aspergillus species, most commonly Aspergillus fumigatus. AIM: To study the prevalence of ABPA in asthmatic patients presenting to our institute. MATERIALS AND METHODS: All consecutive asthma patients attending our allergy clinic Out Patient Department (OPD) over a period of 20 months were tested with skin prick test (SPT) for Aspergillus antigens and those who were found positive were further evaluated for ABPA using Greenberger's criteria. RESULTS: Seventy consecutive asthmatic patients were screened by SPT using Aspergillus antigens. Thirteen patients (18.57%) were found to be SPT positive, out of which nine patients (12.9%) were diagnosed as having ABPA using Greenberger's criteria. ABPA was common among 25-35 age group with no gender predilection. ABPA patients had longer duration of illness, predominantly mixed pattern in PFT, higher mean absolute eosinophil count (AEC) and serum total IgE compared to non-ABPA asthmatic patients. Specific IgE for A. fumigatus was positive in all ABPA patients and serum precipitins were positive in seven patients (77.58%). Chest X-ray abnormalities were seen in five patients (55.6%) and HRCT showed central bronchiectasis in eight patients (88.9%) with varying other radiological features. None were sputum fungal culture positive and five patients (55.6%) have been misdiagnosed as pulmonary tuberculosis in the past. CONCLUSION: The prevalence of ABPA is significantly higher in bronchial asthma patients presenting to tertiary care centers and hence awareness is required among physicians for early diagnosis and management of ABPA to achieve better asthma control and to avoid permanent lung damage.

Epidemiological study of failures of the Jaipur Foot.

OBJECTIVE: The purpose of this study was to examine effects of usage and demographics on damage to the Jaipur Foot prosthesis as well as the epidemiology and etiology of amputations performed at Santokba Durlabjhi Memorial Hospital (SDMH) in Jaipur, India. DESIGN: Total time spent standing, total time spent wearing and total distance walked were compared against severity and location of damage to the prosthesis. Time between initial fitting and follow-up visit for damaged prosthetic was also considered in this analysis. A novel damage severity scale based on prosthesis functionality is presented along with a damage location legend. RESULTS: Patients from 10 different states and two territories throughout India were included in the study. No main effects were found to be statistically significant in predicting severity or location of damage. Only the interaction between a patient's total time spent standing and their total time spent wearing the prosthesis as well as the interaction between a patient's total time spent standing and total distance walked was significant in predicting location of damage to the Jaipur Foot (p = .0327, p = .0278, respectively). CONCLUSIONS: The lack of significant usage factor effect on damage severity or location could support previous findings that lack standardization in materials and manufacturing processes, which is the major drawback of the Jaipur Foot. Implications for Rehabilitation The Jaipur Foot is a safe, reliable and stable product as no abrupt breakage or sudden falls causing injury to the patient were noted. Hence, it is a safe rehabilitation device for lost limbs. The population can squat and sit cross-legged while wearing the prosthetic foot and it does not affect damage severity or location of damage, allowing for these activities to be performed while rehabilitating. The manufacturing of the foot needs to be standardized to improve life of foot. Total time spent standing, total time spent wearing and total distance walked were not predictive of severity or location of damage to the prosthesis, hence providing patient guidelines for activity during rehabilitation.

Reliability and validity of an audio signal modified shuttle walk test.

BACKGROUND: The audio signal in the conventionally accepted protocol of shuttle walk test (SWT) is not well-understood by the patients and modification of the audio signal may improve the performance of the test. OBJECTIVES: The aim of this study is to study the validity and reliability of an audio signal modified SWT, called the Singla-Richa modified SWT (SWTSR), in healthy normal adults. PATIENTS AND METHODS: In SWTSR, the audio signal was modified with the addition of reverse counting to it. A total of 54 healthy normal adults underwent conventional SWT (CSWT) at one instance and two times SWTSRon the same day. The validity was assessed by comparing outcomes of the SWTSRto outcomes of CSWT using the Pearson correlation coefficient and Bland-Altman plot. Test-retest reliability of SWTSRwas assessed using the intraclass correlation coefficient (ICC). The acceptability of the modified test in comparison to the conventional test was assessed using Likert scale. RESULTS: The distance walked (mean ± standard deviation) in the CSWT and SWTSRtest was 853.33 ± 217.33 m and 857.22 ± 219.56 m, respectively (Pearson correlation coefficient - 0.98; P < 0.001) indicating SWTSRto be a valid test. The SWTSRwas found to be a reliable test with ICC of 0.98 (95% confidence interval: 0.97-0.99). The acceptability of SWTSRwas significantly higher than CSWT. CONCLUSIONS: The SWTSRwith modified audio signal with reverse counting is a reliable as well as a valid test when compared with CSWT in healthy normal adults. It better understood by subjects compared to CSWT.

Langerhans cell histiocytosis of the scapula - diagnosis & treatment options / Histiocitose de células de langerhans da escápula - diagnóstico e opções de tratamento / Histiocitosis de células de langerhans de la escápula - diagnóstico y opciones de tratamiento

ABSTRACT Langerhans cell histiocytosis (LCH) is characterised by an abnormal histiocytic accumulation in tissues such as the lung, spleen, bone marrow, skin, central nervous system, liver and lymph nodes, causing focal or systemic effects. No specific clinical & radiographic presentation of LCH is described in literature. This poses a diagnostic dilemma for surgeons. The scapula is the site of 3% of bone tumours, while for LCH it is the least common site. In a 10-year-old boy with isolated lesion of the scapula with no other systemic involvement, and no specific finding in MRI or CT scan of scapula, diagnosis was confirmed on biopsy. Division into single and multi-system disease is paramount in treatment, given that it is a single system disease. The patient improved clinically on follow-up of 2 years. The scapula is one of the rarest site of LCH, and because various lesions mimic each other, a biopsy is always required, with immunohistochemistry for CD68 & S-100. This was only a single system disease, so conservative management was performed, and the patent improved clinically.

RESUMO A histiocitose de células de Langerhans (HCL) caracteriza-se por acúmulo anormal de histiócitos em tecidos como pulmão, baço, medula óssea, pele, sistema nervoso central, fígado e linfonodos, causando efeitos focais ou sistêmicos. Nenhuma apresentação clínica e radiográfica específica da HCL está descrita na literatura. Isso impõe um dilema diagnóstico para os cirurgiões. A escápula é o local de 3% dos tumores ósseos, ao passo que é o lugar menos comum para a HCL. Em um menino de 10 anos de idade, com lesão isolada na escápula e sem outro envolvimento sistêmico, sem achados específicos na RM ou na TC da escápula, o diagnóstico foi confirmado pela biópsia. A divisão entre doença isolada e de múltiplos sistemas é fundamental para o tratamento, considerando-se que este caso é uma doença de um só sistema. O paciente teve melhora clínica no acompanhamento de dois anos. A escápula é um dos locais mais raros de ocorrência da HCL, e como as lesões mimetizam umas às outras, sempre é preciso realizar biópsia por imuno-histoquímica para CD68 e S-100. Esta doença atingiu apenas um sistema, levando ao tratamento conservador e o paciente apresentou melhora clínica.

RESUMEN La histiocitosis de células de Langerhans (HCL) se caracteriza por la acumulación anormal de histiocitos en tejidos como pulmón, bazo, médula ósea, piel, sistema nervioso central, hígado y linfonodos, causando efectos focales o sistémicos. Ninguna presentación clínica y radiográfica específica de la HCL está descrita en la literatura. Eso impone un dilema diagnóstico para los cirujanos. La escápula es el local de 3% de los tumores óseos, al paso que es el lugar menos común para la HCL. En un niño de 10 años de edad, con lesión aislada en la escápula y sin otro compromiso sistémico, sin hallazgos específicos en la RM o en la TC de la escápula, el diagnóstico fue confirmado por la biopsia. La división entre enfermedad aislada y de múltiples sistemas es fundamental para el tratamiento, considerándose que este caso es una enfermedad de un único sistema. El paciente tuvo mejora clínica en el acompañamiento de dos años. La escápula es uno de los locales más raros de ocurrencia de la HCL, y como las lesiones mimetizan unas a otras, siempre es preciso realizar biopsia por inmunohistoquímica para CD68 y S-100. Esta enfermedad alcanzó a sólo un sistema, llevando al tratamiento conservador y el paciente presentó mejora clínica.

Modeling of un-deformed chip thickness in RUM process and study of size effects in µ-RUM.

Un-deformed chip thickness is a critical parameter in machining processes. Measuring un-deformed chip thickness experimentally is a complicated process, especially in micro machining and may not even be measured accurately. The un-deformed chip thickness has an influence on material removal rate, cutting forces, specific energy and surface finish etc. In ceramic machining, it is also an indication of material removal mode such as ductile or brittle fracture. In the present study, an effort is made to model undeformed chip thickness, cutting forces and specific cutting energy in rotary ultrasonic machining (RUM) applied to the side milling operation. RUM may be considered as super-imposition of ultrasonic vibrations on the grinding process. The kinematics of ultrasonic motion has been applied to the grinding for the development of the RUM process models. To validate the models, machining experiments have been performed on borosilicate glass in RUM and grinding modes. Percentage of ductile mode of fracture for the machined surfaces has been evaluated using SEM images. Surface roughness values have also been compared for the same material removal rate conditions to ascertain fracture mode. Developed models have been verified and found that ductile mode of fracture as well as surface finish were higher in RUM as compared to grinding process for same material removal rate. RUM process for six aerospace grade materials has also been tried using micro and macro tools and size effects studied.