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BACKGROUND AND OBJECTIVES: Internal hemipelvectomy is a limb sparing procedure most commonly indicated for malignant bone and soft tissue tumors of the pelvis. Partial resection and pelvic reconstruction may be challenging for orthopedic oncologists due to late presentation, high tumor burden, and complex anatomy. Specifically, wide resection of tumors involving the periacetabular and sacroiliac (SI) regions may compromise adjacent vital neurovascular structures, impair wound healing, or limit functional recovery. We aimed to present a series of patients treated at our institution who underwent periacetabular internal hemipelvectomy (Type II) with or without sacral extension (Type IV) in combination with a systematic review to investigate postoperative complications, functional outcomes, and implant and patient survival following pelvic tumor resection via Type II hemipelvectomy with or without Type IV resection. MATERIALS AND METHODS: A surgical registry of consecutive patients treated with internal hemipelvectomy for primary or secondary pelvic bone tumors at our institution since 1994 was retrospectively reviewed. All type II resection patients were stratified into two separate cohorts, based on whether or not periacetabular resection was extended beyond the SI joint to include the sacrum (Type IV), as per the Enneking and Dunham classification. Patient demographics, operative parameters, complications, and oncological outcomes were collected. Categorical and continuous variables were compared with Pearson's chi square or Fisher's exact test and the Mann-Whitney U test, respectively. Literature review according to PRISMA guidelines queried studies pertaining to patient outcomes following periacetabular internal hemipelvectomy. The search strategy included combinations of the key words "internal hemipelvectomy", "pelvic reconstruction", "pelvic tumor", and "limb salvage". Pooled data was compared using Pearson's chi square. Statistical significance was established as p < 0.05. RESULTS: A total of 76 patients were treated at our institution with internal hemipelvectomy for pelvic tumor resection, of whom 21 had periacetabular resection. Fifteen patients underwent Type II resection without Type IV involvement, whereas six patients had combined Type II/IV resection. There were no significant differences between groups in operative time, blood loss, complications, local recurrence, postoperative metastasis, or disease mortality. Systematic review yielded 69 studies comprising 929 patients who underwent internal hemipelvectomy with acetabular resection. Of these, 906 (97.5 %) had only Type II resection while 23 (2.5 %) had concomitant Type II/IV resection. While overall complication rates were comparable, Type II resection alone produced significantly fewer neurological complications when compared to Type II resection with sacral extension (3.9 % vs. 17.4 %, p = 0.001). No significant differences were found between rates of wound complications, infections, or construct failures. Local recurrence, postoperative metastasis, and survival outcomes were similar. Type II internal hemipelvectomy without Type IV resection on average produced higher postoperative MSTS functional scores than with Type IV resection. CONCLUSION: In our series, the two groups exhibited no differences. From the systematic review, operative parameters, local recurrence or systemic metastasis, implant survival, and disease mortality were comparable in patients undergoing Type II internal hemipelvectomy alone compared to patients undergoing some combination of Type II/IV resection. However, compound resections increased the risk of neurological complications and experienced poorer MSTS functional scores.
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Purpose: To perform a meta-analysis and systematic review to compare the efficacy and complications of micropulse laser trabeculoplasty (MLT) and selective laser trabeculoplasty (SLT) in adult patients with open-angle glaucoma (OAG) and ocular hypertension (OHT). Methods: We performed a systematic review utilizing PubMed, Embase, and Scopus, on April 8, 2024. Meta-analyses were performed for the mean change in intraocular pressure (IOP) at one-month, six-month, and one-year follow-up visits, rate of IOP spikes (>5 mmHg increase from the pre-procedure baseline IOP), rate of treatment failure (<20% or <3 mmHg reduction in IOP or requiring additional medications or procedures), and mean change in number of medications. Results: Six studies, with a total of 593 eyes, were included: 283 underwent MLT, while 310 underwent SLT. A statistically significant difference in the efficacy of MLT versus SLT at one-month and six-month follow-ups was present, with SLT reducing IOP by 0.83 mmHg (95% CI: 0.20, 1.47; P = 0.01) more and 0.55 mmHg (95% CI: 0.02, 1.08; P = 0.04) more than MLT, respectively. At the one-year follow-up, there was no significant disparity in IOP reduction between SLT and MLT (WMD = 0.16; 95% CI: -0.40, 0.71; P = 0.58). There was a significantly lower rate of IOP spikes in the MLT treatment group (RR = 0.37; 95% CI: 0.16, 0.89; P = 0.03). There was no statistically significant difference in the rate of treatment failures (RR = 1.05; 95% CI: 0.68, 1.62; P = 0.84) or number of topical medications reduced (WMD = 0.06; 95% CI: -0.13, 0.26; P = 0.53). Conclusion: While SLT may offer greater short-term reductions in IOP, it may be associated with more postoperative IOP spikes when compared to MLT. At one-year follow-up, there were no significant differences in IOP reduction or failure rates between the MLT and SLT groups.
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Background: In clinical practice, internal fixation (IF) is a commonly utilized technique for metastatic bone disease (MBD) to the distal femur. Additionally, distal femoral reconstruction (DFR) has shown to be an effective surgical technique for primary tumors and MBD in the distal femur. The existing body of research comparing these methods has not focused on MBD or pathological fractures and thus does not guide surgical approach in the case of distal femoral MBD. Methods: A multi-institutional retrospective review of musculoskeletal oncology patients treated surgically with IF (n = 29) or DFR (n = 34) for distal femoral MBD between 2005 and 2023. Overall survival, revision risk, and functional status were assessed. Results: 5-year patient overall survival was 47.9 % (CI, 29.5-77.6 %) and 46.6 % (CI, 31.5-68.8 %), for DFR and IF, respectively (p = 0.91). After competing risk analysis, the 5-year risk of implant revision for DFR was 18 % (95 % CI: 5.1-37 %) and 11 % for IF (95 % CI: 2.4-28 %) (p = 0.3). DFR had longer operative times (p = 0.002), higher blood loss (p < 0.001), and greater postoperative (p = 0.006) complications than IF. In addition, patients undergoing DFR had more distal lesions than patients who received IF (p = 0.003). Conclusion: Despite similar overall survival and revision rates, IF may be preferable for patients due to its shorter operative time and lower rates of complication than DFR. However, specific anatomic location in the distal femur must be considered prior to deciding which procedure is optimal.
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BACKGROUND: Total humeral endoprosthetic reconstruction (THER) is a rare reconstruction option for limb salvage surgery for large humeral neoplasms or bone destruction. MATERIALS AND METHODS: Because of the limited data and need for this procedure, we reviewed the literature surrounding THER and assessed functionality, complications, and revisions using the PubMed, Embase, Ovid, and Scopus databases. RESULTS: Among 29 articles and 175 patients, the most common indication was neoplasm (n=25, 86%), mean follow-up was 61.98 months (SD=55.25 months), and mean Musculoskeletal Tumor Society score was 73.64% (SD=10.69%). Reported complications included 26 (23%) revisions in 7 studies, 35 (36%) cases of shoulder instability in 7 studies, and 13 (13.54%) cases of deep infection in 4 studies. CONCLUSION: THER should be considered with a thorough knowledge of outcomes and potential complications to guide patient and clinician expectations. [Orthopedics. 2024;47(3):e106-e113.].
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Úmero , Humanos , Úmero/cirurgia , Neoplasias Ósseas/cirurgia , Salvamento de Membro/métodos , Procedimentos de Cirurgia Plástica/métodos , Complicações Pós-Operatórias , ReoperaçãoRESUMO
Myxoid/round cell liposarcomas (MRCLPS) are a rare soft tissue sarcoma. We report the largest sarcoma in our institutional history. We discuss the patient's surgical management and treatment of the tumor and challenges given its dimensions. Several complications arose following primary resection that were managed by a multidisciplinary team. Although MRCLPS can vary in size, large MRCLPS must be treated cautiously given the potential for complications. Additionally, multidisciplinary treatment of MRCLPS is essential in diagnosing and treating these complex cases.
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Introduction: Spina bifida is a rare neurological condition that, if uncorrected, may cause chronic valgus knee stress difficulty with independent ambulation and significant pain. Current literature lacks comprehensive guidance on surgically correcting progressive hip and knee deformities in spina bifida patients, which include osteotomy and primary. When these options are contraindicated, alternative approaches such as arthrodesis may be indicated, although they remain understudied in this population. Case Report: A 47-year-old man presented with bilateral hip and knee pain. Radiographs demonstrated valgus knee deformities with severe arthrosis and bilateral femoral head subluxation. The patient had a history of spina bifida with chronic lower extremity weakness and neurogenic bladder. He underwent staged bilateral instrumented knee arthrodesis and staged bilateral total hip arthroplasty (THA). Conclusion: This is the first reported case of bilateral instrumented knee arthrodesis in a patient with spina bifida. Orthopedic care of these patients is complex. Surgical correction of symptomatic knee and hip deformities through instrumented arthrodesis and THA may permit an improved functional outcome.
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PURPOSE: Machine learning (ML) models have been used to predict cancer survival in several sarcoma subtypes. However, none have investigated extremity leiomyosarcoma (LMS). ML is a powerful tool that has the potential to better prognosticate extremity LMS. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of histologic extremity LMS (n = 634). Patient, tumor, and treatment characteristics were recorded, and ML models were developed to predict 1-, 3-, and 5-year survival. The best performing ML model was externally validated using an institutional cohort of extremity LMS patients (n = 46). RESULTS: All ML models performed best at the 1-year time point and worst at the 5-year time point. On internal validation within the SEER cohort, the best models had c-statistics of 0.75-0.76 at the 5-year time point. The Random Forest (RF) model was the best performing model and used for external validation. This model also performed best at 1-year and worst at 5-year on external validation with c-statistics of 0.90 and 0.87, respectively. The RF model was well calibrated on external validation. This model has been made publicly available at https://rachar.shinyapps.io/lms_app/ CONCLUSIONS: ML models had excellent performance for survival prediction of extremity LMS. Future studies incorporating a larger institutional cohort may be needed to further validate the ML model for LMS prognostication.
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PURPOSE: Determine the pediatric prevalence of keratoconus (KC) using Scheimpflug corneal tomography. METHODS: A prospective observational study was done on subjects aged 3 to 18 years at the Princeton Vision Clinic, Chicago, IL. Scheimpflug tomography (Pentacam HR, OCULUS Optikgerate GmbH) scans (Belin/Ambrósio Enhanced Ectasia BAD3) yielded BAD Final D (Final D) and Back Elevation at the Thinnest Point (BETP) measurements. Criteria differentiating non-KC from KC suspects & KC were, Non-KC -Final D <2.00 in both eyes; KC suspect -Final D ≥2.00 and <3.00 in combination with BETP ≥18 µm for myopia and ≥28 µm for hyperopia/mixed astigmatism in at least one eye; and KC -Final D of ≥3.00 with BETP ≥18 µm for myopia or ≥28 µm for hyperopia/mixed astigmatism in at least one eye. Two thousand two hundred and six subjects were recorded, removing duplicate and poor-quality scans leaving 2007 subjects. RESULTS: Of 2007 subjects, six were classified as KC -prevalence of 1:334, three subjects were KC suspects -prevalence of 1:669, and total prevalence of KC suspects and KC was 1:223. CONCLUSION: The prevalence of KC in children is higher than previously reported, emphasizing the importance of sensitive screening for KC at its earliest manifestation as standard in pediatric comprehensive eye examinations.
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Astigmatismo , Hiperopia , Ceratocone , Miopia , Criança , Humanos , Chicago/epidemiologia , Córnea/diagnóstico por imagem , Paquimetria Corneana , Topografia da Córnea/métodos , Ceratocone/diagnóstico , Ceratocone/epidemiologia , Miopia/diagnóstico , Miopia/epidemiologia , Prevalência , Curva ROC , Tomografia , Estudos ProspectivosRESUMO
A patient presented with melanocytoma and associated choroidal neovascular membrane with hemorrhage involving the macula. The patient was treated with monthly aflibercept (Eylea) injections with significant improvement of best corrected visual acuity. In this report, we explore the development of a choroidal neovascular membrane (CNVM) formation in a patient with melanocytoma and the effect of intravitreal aflibercept (Eylea) on disease course. Case report study used patient data obtained from examination and imaging. The patient was treated with monthly intravitreal aflibercept injections leading to complete resolution of CNVM and hemorrhage, with significant improvement of best corrected visual acuity. Awareness and proper monitoring for the sequelae of melanocytoma are important for early detection and prevention of visually threatening outcomes. In cases of melanocytoma-associated CNVM formation with large subretinal hemorrhage, intravitreal aflibercept can be an effective tool for inducing CNVM regression and allowing improvement of visual acuity.
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CASE: A 10-year-old boy presented with bilateral absent patella and dislocation of the extensor mechanism in the left lower extremity. He underwent a lateral release and medial plication of the extensor mechanism with a Roux-Goldthwait procedure, followed by casting and bracing treatment. The patient fully recovered with a return to sports and improved active range of motion. CONCLUSION: Bilateral absent patella without other congenital anomalies is an exceedingly rare condition and can be accompanied by a dislocation of the extensor mechanism. Treatment should address functional limitations, including extensor mechanism dislocation, when present.
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Luxações Articulares , Deformidades Congênitas das Extremidades Inferiores , Anormalidades Musculoesqueléticas , Masculino , Criança , Humanos , Extremidade Inferior , BraquetesRESUMO
OBJECTIVES: To report on the topographic and visual outcomes 10 years after corneal cross-linking in patients with progressive keratoconus and corneal ectasia after refractive surgery. METHODS: Cross-sectional cohort study of an original, prospective, randomized, clinical trial. Patients treated in a single center cornea and refractive surgery practice as part of the U.S. pivotal trials, which led to the Food and Drug Administration approval of corneal cross-linking, were recruited for a 10-year follow-up examination. LogMar lines (LL) of uncorrected visual acuity (UCVA) and best spectacle--corrected visual acuity (BSCVA), maximum keratometry, and thinnest pachymetry were evaluated. In addition, the Belin ABCD progression display was used to determine progression (95% confidence interval) of the anterior curvature, posterior curvature, and corneal thickness of each individual eye included. RESULTS: Nineteen eyes of 13 patients treated with standard cross-linking returned for a 10-year follow-up examination. Mean maximum keratometry changed from 58.2±12.0 diopters (D) to 58.3±10.1 D, thinnest pachymetry changed from 440.6±51.6 µm to 442.3±54.4 µm, UCVA changed from 0.79±0.42 LL to 0.86±0.46 LL, and BSCVA changed from 0.38±0.26 LL to 0.33±0.34 LL, 10 years after cross-linking. Individually, 68.5% of the entire cohort, 81.8% of keratoconus eyes, and 50% of eyes with corneal ectasia remained topographically stable 10 years after standard cross-linking. CONCLUSIONS: In the entire cohort, visual acuity and topography remained stable 10 years after cross-linking. Over the long-term, eyes with keratoconus seem to be more stable than those with corneal ectasia.
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Ceratocone , Fotoquimioterapia , Humanos , Crosslinking Corneano , Substância Própria , Topografia da Córnea , Reagentes de Ligações Cruzadas/uso terapêutico , Estudos Transversais , Dilatação Patológica/tratamento farmacológico , Seguimentos , Ceratocone/tratamento farmacológico , Ceratocone/diagnóstico , Fármacos Fotossensibilizantes/uso terapêutico , Estudos Prospectivos , Riboflavina/uso terapêutico , Raios UltravioletaRESUMO
OBJECTIVES: To report on baseline refractive and keratometric values and their correlation with tomographic characteristics of eyes with keratoconus (KC). METHODS: Retrospective chart review of patients treated in a single-center cornea and refractive surgery practice. Baseline topographic measurements were reviewed for 1,012 keratoconic eyes of 586 patients between 2008 and 2018. The manifest refraction, thinnest pachymetry (P thin ), corneal astigmatism (K astig ), and the maximum (K max ), steep (K steep ), flat (K flat ), and mean (K mean ) keratometry were analyzed. The location of K max (x, y) was used to determine central (<1 mm), paracentral (1-3 mm), pericentral (3-5 mm), or peripheral (>5 mm) cone locations. RESULTS: In the entire cohort, the mean manifest sphere was -2.2±4.4 diopters (D) and the cylinder was -3.2±2.3 D. In total, 48.6% of patients had against the rule (ATR) manifest astigmatism (M astig ). The average K astig was 3.8±2.7 D, and unlike the manifest axis, 50.2% of patients had with the rule (WTR) K astig . Patients with a K max less than 50 D had an M astig of -1.9±1.6 D, 45.9% of which was ATR M astig . With respect to baseline tomography measurements, K max , K steep , K flat , and K mean were 58.0±9.4, 50.6±6.5, 46.8±5.9, and 48.6±6.1 D, respectively. There was a weak correlation between K max and simulated keratometry (K steep , K flat , and K mean ) for patients with a K max less than 60 D. CONCLUSIONS: Simulated keratometry is poorly correlated with KC severity until the disease is more severe. M astig ≥2 D and ATR M astig were correlated with KC at all levels of severity. M astig ≥2 D and ATR M astig may serve as a simple, inexpensive, and widely available indicator for topographic analysis to identify possible KC and suggest further workup; however, further prospective studies are needed to confirm its utility.
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Astigmatismo , Ceratocone , Humanos , Ceratocone/diagnóstico , Ceratocone/terapia , Estudos Retrospectivos , Topografia da Córnea/métodos , Córnea/diagnóstico por imagem , Refração Ocular , Astigmatismo/diagnóstico , TomografiaRESUMO
ABSTRACT: In this report, we discuss contact lens (CL) fitting in a patient with a history of keratoconus (KC), before and after undergoing topography-guided photorefractive keratectomy (TG PRK). Before TG PRK, the patient failed multiple CL modalities and reported difficulty with his habitual CLs and inadequate spectacle-corrected visual acuity to perform his activities of daily living. In this case, a collaborative, comprehensive approach to visual management in a patient with KC was used, and after TG PRK was performed to improve his corneal contour and symmetry, our patient was fit with a standard soft CL and additionally had improved spectacle-corrected visual acuity.
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Lentes de Contato Hidrofílicas , Ceratocone , Ceratectomia Fotorrefrativa , Humanos , Ceratectomia Fotorrefrativa/efeitos adversos , Ceratocone/cirurgia , Atividades Cotidianas , Lasers de Excimer/uso terapêutico , Acuidade Visual , Topografia da Córnea , Lentes de Contato Hidrofílicas/efeitos adversos , Reagentes de Ligações CruzadasRESUMO
PURPOSE: To report results of Corneal Tissue Addition Keratoplasty (CTAK) for keratoconus (KC) and ectasia after laser in situ keratomileusis. SETTING: Cornea and refractive surgery practice. DESIGN: Single center, prospective, open label clinical trial. METHODS: 21 eyes of 18 patients underwent CTAK. A tissue inlay of preserved corneal tissue was cut to customized specifications with a femtosecond laser and placed in a laser-created channel in the host cornea. Postoperative uncorrected and corrected distance visual acuity (UDVA, CDVA), manifest refraction spherical equivalent (MRSE), topographic mean keratometry (Kmean), maximum keratometry (Kmax), and the point of maximum flattening (Kmaxflat) were measured. RESULTS: Average UDVA improved from 1.21 ± 0.35 logMAR lines (LL) (20/327) to 0.61 ± 0.25 LL (20/82) ( P < .001). Average CDVA improved from 0.62 ± 0.33 LL (20/82) to 0.34 ± 0.21 LL (20/43) ( P = .002), and average MRSE improved from -6.25 ± 5.45 diopters (D) to -1.61 ± 3.33 D ( P = .002). Individually, 20 eyes (95.2%) gained more than 2 lines of UDVA, with 10 eyes (47.6%) gaining more than 6 lines, and no eyes worsening. 12 eyes (57.1%) gained at least 2 lines of CDVA, with 1 eye worsening by more than 2 lines. At 6 months, average Kmean flattened by -8.44 D ( P = .002), Kmax flattened by -6.91 D ( P = .096), and mean Kmaxflat was -16.03 D. CONCLUSIONS: CTAK is a promising procedure to improve visual acuity and topography in patients with KC and ectasia.
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Transplante de Córnea , Ceratocone , Humanos , Córnea/cirurgia , Substância Própria/cirurgia , Topografia da Córnea , Transplante de Córnea/métodos , Dilatação Patológica/cirurgia , Ceratocone/cirurgia , Lasers , Estudos Prospectivos , Implantação de Prótese , Refração OcularRESUMO
INTRODUCTION: Total joint arthroplasty (TJA) volume and the number of orthopaedic surgeons in the United States have increased in recent years, but local growth variation has not been studied. This study assesses recent changes in state-level distribution of orthopaedic surgeons in the United States and corresponding local trends in TJA volume. METHODS: Data from the National Inpatient Sample database (2000 to 2014) were reviewed. Urban versus rural setting and teaching versus nonteaching hospitals were identified among TJA procedures for comparison. Data from the American Academy of Orthopaedic Surgeons (2002 to 2016) detailing orthopaedic surgeon practice location were evaluated, and linear regression analysis was used to correlate state population data with orthopaedic surgeon density. RESULTS: From 2000 to 2014, there was a 0.1% to 0.3% (P < 0.01) annual decrease in the proportion of TJA procedures conducted in rural hospitals. No notable change was observed in the proportion of TJA procedures conducted at urban teaching versus nonteaching hospitals. Linear regression analysis demonstrated that decreased state population was associated with higher orthopaedic surgeon density (adjusted R2 = 0.114, P < 0.01). States with a higher percentage of population living in rural areas had a lower density of orthopaedic surgeons in the South region and a higher density of orthopaedic surgeons in the remainder of the county. CONCLUSIONS: Less populated, rural states have a higher density of orthopaedic surgeons than states with increased population and less rural areas. Although TJA volume has increased since 2000, the proportion of TJA procedures conducted at rural hospitals has decreased. No change was found in the proportion of TJA procedures conducted at urban teaching versus nonteaching hospitals. This may indicate that more patients living in rural areas are seeking TJA care in urban centers. Future studies are needed to confirm this and ensure that patients living in rural areas have appropriate access to TJA care.
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Cirurgiões Ortopédicos , Artroplastia , Hospitais Rurais , Humanos , Pacientes Internados , População Rural , Estados UnidosRESUMO
PURPOSE: Enhanced Recovery after Surgery (ERAS) pathways have been shown to decrease length of stay (LOS) after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). The aim of this study was to compare immediate post-operative outcomes following an ERAS pathway with a traditional pathway for AIS. METHODS: A prospective dual-center study of patients treated using an ERAS pathway (203 patients) or a traditional discharge (TD) pathway (73 patients) was performed with focus on pain at discharge, quality of life at one month, and return to school/work. RESULTS: LOS was 55% less in the ERAS group (4.8 days TD vs. 2.2 days ERAS, p < 0.001). Length of surgery (4.8 h TD vs. 2.8 h, p < 0.001) and EBL (500 cc vs. 240 cc, p < 0.001) were greater in the TD group, likely related to larger curve magnitudes ((62.0° TD vs. 54.0° ERAS, p < 0.001), a higher percentage of patients undergoing osteotomies (94% vs. 46%, p < 0.001) and more levels fused (11.4 ± 1.6 vs. 10.1 ± 2.6, p < 0.001) in the TD group. Regression analysis showed no difference in Visual Analog Score (VAS) score at discharge or quality of recovery using the QOR9 instrument between groups at follow up. There was no difference in return to school (p = 0.43) and parents' return to work (p = 0.61) between the groups. CONCLUSION: Patients managed with an ERAS pathway had similar pain scores at discharge than those managed with a TD pathway. Both groups showed evidence of rapid return to normalcy by the first follow up visit.
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Recuperação Pós-Cirúrgica Melhorada , Escoliose , Fusão Vertebral , Adolescente , Humanos , Alta do Paciente , Estudos Prospectivos , Qualidade de Vida , Estudos Retrospectivos , Escoliose/cirurgiaRESUMO
BACKGROUND: With the recent removal of total knee arthroplasty (TKA) from the Centers for Medicare and Medicaid Services (CMS) Inpatient Only list, facility reimbursement for outpatient TKA now falls under the Outpatient Prospective Payment System at the same rate as unicompartmental knee arthroplasty (UKA). The purpose of this study was to compare true facility costs of patients undergoing outpatient TKA with those undergoing UKA. METHODS: We reviewed a consecutive series of 2310 outpatient TKA and 231 UKA patients from 2018 to 2019. Outpatient status was defined as a hospital stay of less than 2 midnights. Facility costs were calculated using a time-driven, activity-based costing algorithm. Implants, supplies, medications, and personnel costs were compared between outpatient TKA and UKA patients. A multivariate analysis was performed to control for confounding medical and demographic variables. RESULTS: When compared with patients undergoing UKA, outpatient TKA patients had higher implant costs ($3403 vs $3081; P < .001) and overall hospital costs ($6350 vs $5594; P < .001). Outpatient TKA patients had a greater length of stay (1.2 vs 0.5 days; P < .001) and greater postoperative personnel costs ($783 vs $166; P < .001) than UKA patients. When controlling for comorbidities, outpatient TKA was associated with a $803 (P < .001) increase in overall facility costs compared with UKA. CONCLUSION: Despite equivalent reimbursement from CMS as UKA, outpatient TKA has increased facility costs to the hospital. Although implant costs can vary greatly by institution, CMS should consider appropriately reimbursing outpatient TKA for the additional personnel costs when compared with UKA.
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Artroplastia do Joelho , Osteoartrite do Joelho , Idoso , Centers for Medicare and Medicaid Services, U.S. , Humanos , Articulação do Joelho/cirurgia , Tempo de Internação , Medicare , Osteoartrite do Joelho/cirurgia , Pacientes Ambulatoriais , Resultado do Tratamento , Estados UnidosRESUMO
BACKGROUND: The goal of kinematically aligned (KA) total knee arthroplasty (TKA) is to restore native knee anatomy. However, there are concerns about patellofemoral tracking problems with this technique that lead to early revision. We measured the differences between preoperative anatomic alignment and postoperative component alignment in a consecutive series of KA TKA and evaluated the association between alignment changes and the likelihood of early revision. METHODS: The charts of 219 patients who underwent 275 KA TKA procedures were reviewed. Preoperative anatomic alignment and postoperative tibial and femoral component alignment were measured radiographically. The difference in component alignment compared with preoperative anatomic alignment was compared between patients who underwent aseptic revision and those who did not at a minimum of 12 months of follow-up. Receiver operating characteristic curves were created for statistically significant variables, and the Youden index was used to determine optimal alignment thresholds with regard to likelihood of revision surgery. RESULTS: Change in tibial component alignment compared with native alignment was greater (P = .005) in the revision group (5.0° ± 3.7° of increased varus compared with preoperative anatomic tibial angle) than in the nonrevision group (1.3° ± 4.2° of increased varus). The Youden index indicated that increasing tibial varus by >2.2° or more is associated with increased likelihood of revision. Preoperative anatomic alignment and change in femoral alignment and overall joint alignment (ie, Q angle) were not associated with increased likelihood of revision. CONCLUSION: Small increases in tibial component varus compared with native alignment are associated with early aseptic revision in patients undergoing KA TKA.
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Artroplastia do Joelho , Prótese do Joelho , Osteoartrite do Joelho , Artroplastia do Joelho/efeitos adversos , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/cirurgia , Tíbia/diagnóstico por imagem , Tíbia/cirurgiaRESUMO
Protein engineering is an important tool for the design of proteins with novel and desirable features. Templates from the protein databank (PDB) are often used as initial models that can be modified to introduce new properties. We examine whether it is possible to reconnect a protein in a manner that generates a new topology yet preserves its structural integrity. Here, we describe the rethreading of dihydrofolate reductase (DHFR) from E. coli (wtDHFR). The rethreading process involved the removal of three native loops, and the introduction of three new loops with alternate connections. The structure of the rethreaded DHFR (rDHFR-1) was determined to 1.6 Å, demonstrating the success of the rethreading process. Both wtDHFR and rDHFR-1 exhibited similar affinities towards methotrexate. However, rDHFR-1 showed no reducing activity towards dihydrofolate, and exhibited about ~6-fold lower affinity towards NADPH than wtDHFR. This work demonstrates that protein rethreading can be a powerful tool for the design of a large array of proteins with novel structures and topologies, and that by careful rearrangement of a protein sequence, the sequence to structure relationship can be expanded substantially.
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Proteínas de Bactérias/genética , Engenharia de Proteínas/métodos , Tetra-Hidrofolato Desidrogenase/genética , Sequência de Aminoácidos , Proteínas de Bactérias/química , Bases de Dados Factuais , Escherichia coli , Modelos Moleculares , Estrutura Terciária de Proteína , Tetra-Hidrofolato Desidrogenase/químicaRESUMO
BACKGROUND: SNP genotyping typically incorporates a review step to ensure that the genotype calls for a particular SNP are correct. For high-throughput genotyping, such as that provided by the GenomeLab SNPstream instrument from Beckman Coulter, Inc., the manual review used for low-volume genotyping becomes a major bottleneck. The work reported here describes the application of a neural network to automate the review of results. RESULTS: We describe an approach to reviewing the quality of primer extension 2-color fluorescent reactions by clustering optical signals obtained from multiple samples and a single reaction set-up. The method evaluates the quality of the signal clusters from the genotyping results. We developed 64 scores to measure the geometry and position of the signal clusters. The expected signal distribution was represented by a distribution of a 64-component parametric vector obtained by training the two-layer neural network onto a set of 10,968 manually reviewed 2D plots containing the signal clusters. CONCLUSION: The neural network approach described in this paper may be used with results from the GenomeLab SNPstream instrument for high-throughput SNP genotyping. The overall correlation with manual revision was 0.844. The approach can be applied to a quality review of results from other high-throughput fluorescent-based biochemical assays in a high-throughput mode.