Background: The average age at menarche (AAM) among girls is influenced by various factors, including the socioeconomic status of the country, geographical location, and anthropometric characteristics. In Mongolia, limited research has been conducted on this topic Aim: This study aimed to compare the mean age at menarche among girls living in Bayanzürkh District of Ulaanbaatar and those in Uvs Province. Materials and Methods: A cross-sectional study was conducted between April and June 2025. The study participants included schoolgirls aged 8 years and older from general education schools located in Bayanzürkh District and Uvs Province. Statistical analyses were performed using R version 4.5.1 (RStudio 2025.05.1-513) Results: A total of 486 girls participated in the study. The mean age at menarche among the participants was 12.23±1.29 years. The mean age at menarche among girls aged 8–18 years in Bayanzürkh District was 11.84±1.19 years, while that among girls aged 8–18 years in Uvs Province was 12.97±1.15 years. Thus, girls in Bayanzürkh District experienced menarche 1.13 years earlier on average than those in Uvs Province. The difference in mean AAM between urban (Ulaanbaatar) and rural (Uvs Province) girls was statistically significant (p<0.0001). Conclusion The mean age at menarche among girls residing in Bayanzürkh District was significantly lower than that of girls living in Uvs Province, indicating a tendency toward earlier onset of menarche in urban areas.

Background: To determine the visual and anatomical outcomes after rhegmatogenous retinal detachment surgery. Methods: Case files of patients who had surgery for rhegmatogenous retinal detachment at the 3rd state central hospital May 2019 and May 2021 were reviewed. Information obtained included age, sex, presenting and post-operative visual acuity, anatomical reattachment, post- operative complications and causes of treatment failure. Results: Risk factors for retinal detachment included myopia in 8 eyes (32%), trauma in 7 eyes (28%), prior cataract surgery in 2 eyes (8%). 22 eyes (88%) presented with macula off while 3 eyes (12%) presented with macula partly or completely attached. Visual acuity at presentation was <0.01 in 15 eyes (60%). Following surgery, retina was attached in 23 eyes (92%) and remained detached 2 eyes (8%). Visual acuity after surgery was 0.1< 17 eyes, 0.4< 7 eyes. Visual acuity improved in 23 eyes (84%), remained the same in 2 eyes (8%). Conclusion Myopia and trauma are important risk factors for Rhegmatogenous Retinal Detachment. Majority of patients in this setting presented late with Rhegmatogenous Retinal Detachment and this was responsible for relatively poor visual outcomes despite good anatomical results after surgery. Proper screening of eyes at risk and education of patients is important for preventing visual loss due to retinal detachment.

Introduction: Orthopedic surgery is a highrisk of surgical formation of thromboemboliccomplications.Many researchers are exploringprevent surgical complications.Anticoagulanttreatment is the first choice to preventthromboembolic complications.Artificial jointreplacement surgery has been made in 2008,in National First Central Hospitals (NFCH).Wehave not guideline of anticoagulant treatmentafter surgery and have not principle of choisefollow-drug treatment and unclear testingschedule to monitor anticoagulant treatment,that has become the basis for this study. Westudied by comparing a comparative benefitfor anticoagulant treatment of unfractionatedand low molecular weight heparin results.And studied thromboembolic complications,monitoring test of anticoagulant treatment,fatal bleeding, changes hemostasis ofanticoagulant therapy in both groups. Thesurvey results in practice is doing researchaims to introduce and review the results of thelong-term results.Materials and Methods: Included in thesurvey about 1,400 patients, who had kneeand hip replacement surgery in 2008-2016, inJoint Center of NFCH. All patients are dividedin three group. The first group is control group,do not use anticoagulation treatment, in thesecond group used unfractionated heparin andin the third group used low-molecular-weightheparin.Each group studied comparativewhether thromboembolic complications anddeath caused by thromboembolic, fatalbleeding.Between surgical complication andanticoagulant therapy relationship to investigatethe relationship the correlation is likely trueof 95%. Caused by other thromboemboliccomplications detected cases were removedfrom the study.Results: Control groups has not hospitalmortality, but has 3 cases of sudden death ina after discharge.Hemostasis is longer (INR1,3-1,5) in the second group. There hospitalmortality occurred in 1 (cardiac infarction),and thromboembolic complications 1 (arterialthrombosis in the jugular) in the third group.Low molecular weight heparin are no changeshemostasis, it is strongly dependent (r=0,8).Also in this group there is no fatal bleeding.Conclusions: Orthopedic surgery isnecessary for prevention of thromboemboliccomplications are showing from in controlgroup has sudden death.2 groups have not fatalbleeding when used heparin in normal doses.Other countries researchers conclude lowmolecular-weight-heparin is more effectivethan unfractionated heparin, our study is notvisible correlation reliability.When used lowmolecularweight heparin, hemostasis is notchanged is showing a strong dependence.

Introduction: We performed more than1200 arthroplasty surgeries at National FirstCentral Hospitalfrom 2008, so we haveour surgical technique and experiences.Thepurpose of this study is to assess our surgicalresults and complications after surgery forfemoral neck fracture made in Joint Center,National First Central Hospital, and tocomparingsimilar studies in other countries,and to develop the best optionsurgicaltherapy.Materials and Methods: Between 2008-2015, hip replacement surgery accountedatotal of 168 cases, that was 13.9% allof replacement surgery. A retrospectiveanalysis of patient database based onhospital discharge data and medical recordswas performed. The medical records ofthese patients were reviewed to confirmthe presence of a surgical site infection asdescribed by the Centers for Disease Control(CDC)/NNIS guidelines.Results: Between 2008-2015, in theJoint Center,National First Central Hospital,are seeing increasing number of patientswith hip replacement surgery each year.The cause for hip replacement surgery isaseptic necrosis (42%), at second is femoralneck fractures (22%). Joint Center,NationalFirst Central Hospital currently not providedemergency trauma care center. Therefore,younger patient with femoral neck fracturewas not to happen duringresearch. Olderthan 60 year patients with osteoporosis and,in some cases with nonunion, was doneforhip replacement surgery. The averageage of 75.7 (61-87).Bipolar hip arthroplastywas 14 cases all of 36 patients with femoralneck fracture.9 (5,31%), complications ariseall of hip replacement surgery (168 cases).Including: Infection - 1 (0.59%), sliding - 1(0.59%), dislocation - 2 (1.78%), fracture- 2 (1,18%), nerve injury - 2 (1,18%) andpostoperative mortality - 1 (0.59%).Conclusion: Internal Fixation- for patientage under 60 andgood bone quality. Thatoperation complication is femoral headnecrosis, not healing /nonunion/ delivery ofa lot of research that shows focus. Further,most surgery for femoral neck fracture is hipreplacement that is expected to be widelyavailable.

Introduction: Artificial joint replacementsurgery started in 2008, in Joint centerof National First Central Hospital. Hasexperienced a variety of post-surgicalcomplications.Postoperative infectiouscomplications, prevent and investigate thecauses of the research is carried out todetermine whether the opportunity.Materials and Methods: Facilitiesrandomly selected cases difficult patientswith postoperative septic, and analyzedby descriptive method. In all cases,Bacteriological analysis of the clinicallaboratory department of joint fluidsamples received. We determined artificialjoints causes of postoperative infectiouscomplications and artificial joints determinethe factors of postoperative infectiouscomplications. Calculate the treatment ofinfectious complications.Results: Since 2008, done a total1200 with an artificial joint replacementsurgery. Each year, a surgical number isincreasing. 82% of all cases were kneeartificial joint replacement surgery and18% were hip artificial joint replacementsurgery. There are 20 cases of postoperativeinfectious complications.Most suppurativecomplications (14 cases, 70%) are earlycomplications, that directly related to thesurgery and hospital infections are likelyto be. Pathogenic bacterial samples weredetected 10 cases. An assay blanks dependon laboratory capacity and the number ofsamples. Open surgery is 83,3% effective,when early infectious period. No mortalitydue to infectious complications in our center.Conclusion: The main reason of thepostoperative infectious complications ofartificial joint surgery is S. Aureus (99%).14 cases (70%) of all postoperativecomplications are early complications, thatdirectly related to the surgery and hospitalinfections are likely to be. The main factorsaffecting disinfection of the surgical roomand trauma.

joints with severe defects of the medialtibia usually progress as varus or valgusdeformities, with daily functional handicapssuch as, limping, aches and instability. Duringthe last seven years, in total 1200 knees ofpatients were treated by both bilateral andunilateral total knee arthroplasty in the Jointcenter of National First Central Hospital. Thisresearch shed a light on patients that weretreated by unilateral total knee arthroplastyto correct large defects of tibia.Materials and Methods: The objectiveof this paper is to compare patients whowere treated with auto bone graft withpatients who were treated without auto bonegraft, in order to assess the effectiveness ofthe auto bone graft technique through theretrospective method.Results: The unilateral total kneearthroplasty was operated on 553 patients,30 (5,42%) of whom were treated withautobone graft and 523(94,58%) of whomwere treated without the auto bone graft.Postoperative complication was observed in3 cases (9,9%) among the first group ofpatients, and in 25 cases (4,5%) amongthe second group of patients. As patients,diagnosed with osteoarthrotic knees withsevere tibial bone defects, were treatedthrough the auto bone graft, it could beconcluded that more complications wereobserved on patients with large tibialbone losses. However, no complicationwas observed in other 27 cases that weretreated with the bone graft during the postoperativefollow-up period ranged fromtwelve to eighty four months.Conclusion: In conclusion, total kneearthroplasty using auto bone graft forpatients with severe tibial bone defects iseconomically as well as clinically effectivetechnique for our country.

Environmental pollution, manufactured cities related to human activities such as soil contaminated by heavy metals pollution is one of the problems of the world’s major cities. Heavy metals are one of the main sources of pollution and the environment through biogeochemical cycles, and stored for a long time in the body of living organisms, poisoning is able to generate a negativeimpact on human health. Ulaanbaatar, 2010, along the main road in 11 point analysis of 22 soil samples from some of the heavy metal pollution in the soil lead levels were within normal limits,but the high concentration of topsoil is defined. A study conducted in 2011, but the average leadconcentration of 47.3 ppm healthy uncontaminated soil that is 3-4 times larger than defined.Heavy metals in the soil pollution, but pollution levels being conducted quarterly study and their sources of research have been identified. Heavy metal contamination of Ulaanbaatar soil andcalculation of the amount of heavy metals enter the body. Specialized inspection agency of Ulaanbaatar cities laboratory analysis conducted, the data used as descriptive research study design, participated in the study. Metropolitan areas in the 80 point balance divided analyzed by standard analysis of soil samples collected in spring and autumn, MNS5850:2008 was assessed by comparison with the standard.The average amount of lead in the soil of Ulaanbaatar 18.09 mg/kg (95%CI 13.7-22.4mg/kg), and cadmium concentration of 1.02 mg/kg (95%CI 0.7-1.3mg/kg), the mercury concentration of0.03 mg/kg (95%CI 0.006-0.05 mg/kg) that “The quality of the soil, and soil pollutants, maximum permissible elements” MNS5850:2008 standards, compared to less than the maximum allowed. Lead in the soil through the ingestion 11.75x10-3 mg/kg/day (95%CI 8.9-14.55x10-3 mg/kg/day) and cadmium 0.66x10-3 mg/kg/day (95%CI 0.45-0.84x10-3 mg/kg/day) of mercury 0.02x10-3 mg/kg/day (95%CI 0.0-0.03x10-3 mg/kg/day), and inhalation of lead 1.06x10-6 mg/m3 (95%CI 0.80-1.32x10-6 mg/m3) and cadmium 0.06x10-6 mg/m3 (95%CI 0.00-0.08x10-6 mg/m3), dermal adsorption lead 2.62x10-6 mg/kg/day (95%CI 1.98-3.24x10-6 mg/kg/day) and cadmium 0.15x10-6 mg/kg/day (95%CI 0.10-0.19x10-6 mg/kg/day) be digestible. Ulaanbaatar soil containing lead, cadmium, mercury, “The quality of the soil, and soil pollutants, maximum permissible elements” MNS5850:2008 compared to less than the maximum permitted levels. Three entry through access to the body of heavy metals in the soil to estimate the amount of mercury and cadmium lead digestive, respiratory and skin is a little more access.