Malaria elimination campaigns in the Lake Kariba region of Zambia: a spatial dynamical model

Background As more regions approach malaria elimination, understanding how different interventions interact to reduce transmission becomes critical. The Lake Kariba area of Southern Province, Zambia, is part of a multi-country elimination effort and presents a particular challenge as it is an interconnected region of variable transmission intensities. Methods In 2012-13, six rounds of mass-screen-and-treat drug campaigns were carried out in the Lake Kariba region. A spatial dynamical model of malaria transmission in the Lake Kariba area, with transmission and climate modeled at the village scale, was calibrated to the 2012-13 prevalence survey data, with case management rates, insecticide-treated net usage, and drug campaign coverage informed by surveillance. The model was used to simulate the effect of various interventions implemented in 2014-22 on reducing regional transmission, achieving elimination by 2022, and maintaining elimination through 2028. Findings The model captured the spatio-temporal trends of decline and rebound in malaria prevalence in 2012-13 at the village scale. Simulations predicted that elimination required repeated mass drug administrations coupled with simultaneous increase in net usage. Drug campaigns targeted only at high-burden areas were as successful as campaigns covering the entire region. Interpretation Elimination in the Lake Kariba region is possible through coordinating mass drug campaigns with high-coverage vector control. Targeting regional hotspots is a viable alternative to global campaigns when human migration within an interconnected area is responsible for maintaining transmission in low-burden areas

Use of Denosumab in Children With Osteoclast Bone Dysplasias: Report of Three Cases.

Denosumab has been used successfully to treat disease-associated osteoclast overactivity, including giant cell tumor of bone. Given its mechanism of action, denosumab is a potent potential treatment of other osteoclast bone dysplasias including central giant cell granuloma (CGCG), aneurysmal bone cyst (ABC), and cherubism. Relatively little is known about the safety and efficacy of denosumab in patients with these conditions, especially in children. We report on 3 pediatric patients treated with denosumab over a 3-year period at UCLA Medical Center (Los Angeles and Santa Monica, CA, USA): a 12-year-old with recurrent ABC of the pelvis, a 14-year-old with CGCG of the mandible, and a 12-year-old with cherubism. All were started on a 1-year course of 15 doses 120 mg s.c., given monthly with two loading doses on day 8 and 15. All patients demonstrated rapid and pronounced clinical improvement while on denosumab, including a significant reduction in pain and sclerosis of lytic lesions on radiographs. Within 1 month of initiating therapy, 2 patients experienced hypocalcemia (Common Terminology Criteria for Adverse Events [CTCAE] grade 2) and hypophosphatemia, with 1 patient experiencing symptoms. One patient went on to experience symptomatic rebound hypercalcemia (CTCAE grade 4) 5 months after completing therapy, requiring bisphosphonates and calcitonin. For the second patient, we developed a schedule to wean denosumab involving the progressive lengthening of time between doses from 1 to 4 months in 1-month increments before cessation. We found that denosumab therapy results in significant clinical and radiographic improvement for pediatric patients with nonresectable ABC, CGCG, and cherubism. Problems with serum calcium may be more common in younger patients, with symptomatic and protracted rebound hypercalcemia after cessation of therapy the most significant. We present a potential solution to this problem with progressive spacing of doses. Potential serious adverse events from alterations in calcium homeostasis should be explored in prospective clinical trials. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research

MELD score predicts short-term outcomes after surgical management of proximal humerus fractures: a matched analysis

ObjectiveWe aimed to evaluate the difference in 30-day outcomes after surgical management of proximal humerus fractures (PHFs) between patients with and without chronic liver disease as defined by a MELD score greater than 10.DesignThis was a retrospective database review.SettingAll centers participating in the American College of Surgeons National Surgical Quality Improvement Program database were included.Patients/participantsPatients with proximal humerus fractures who (1) underwent ORIF, HA, or SA and (2) had calculable MELD scores were included.InterventionOpen reduction and internal fixation, hemiarthroplasty, or shoulder arthroplasty was used for treatment.Main outcome measurementsThirty-day complications, mortality, readmission, and reoperation rates were measured.ResultsOf the total 1732 PHF patients identified, 300 had a MELD score higher than 10. After propensity matching by significant covariates, MELD score higher than 10 was found to be significantly associated with higher rates of 30-day mortality, 30-day readmission, transfusion within 72 hours, and systemic complications. Among patients with a MELD score higher than 10, treatment with SA or HA instead of ORIF was associated with a higher rate of transfusion and longer operative time. There were no significant differences between treatment cohorts regarding mortality, reoperation, readmission, or complications.ConclusionsA MELD score higher than 10 is associated with higher risk of surgical complications, transfusion, and death in patients undergoing surgery for proximal humerus fractures. Among patients with a MELD score higher than 10, ORIF was associated with a lower transfusion rate and shorter operative time than arthroplasty or hemiarthroplasty.Level of evidencePrognostic Level III

The Utility of Routine Radiographic Monitoring in Pediatric Osteoarticular Infections

BackgroundPediatric musculoskeletal (MSK) infections broadly include isolated osteomyelitis (OM), septic arthritis (SA), and combined infections (OM+SA). These diagnoses are often monitored with serum inflammatory markers and serial radiographs to monitor treatment response and development of negative sequelae, despite limited data supporting these practices. The purpose of this study is to evaluate the utility of obtaining serial radiographic follow-up for pediatric osteoarticular infections.MethodsAn institutional review board-approved retrospective review was completed. Children 18 years and below admitted to a single institution with a culture/biopsy-proven diagnosis of OM, SA, or OM+SA. All postdischarge radiographs were reviewed and retrospectively categorized as either routine (scheduled) or reactive. Routine radiographs were obtained regardless of clinical presentation. Reactive radiographs were obtained in patients presenting with the sign of an altered clinical course. Negative sequelae, defined as growth arrest/disturbance, pathologic fracture, recurrent MSK infection, and underlying neoplastic process, were recorded and tracked. Descriptive statistics were used to summarize demographic and outcome variables. Number needed to screen (NNS) was defined as the inverse of the incidence of negative sequelae detected.ResultsA total of 131 patients were included for analysis, with a mean age of 11.9 years (SD: 4.96 y). Ninety (69%) patients were diagnosed and treated for OM, 25 (19%) for SA, and 16 (12%) for combined infections. A total of 329 radiographs were obtained following discharge. Of those obtained, 287 (88%) were routine, resulting in the detection of 2 (0.7%) negative sequelae and a resultant NNS of 143 radiographs (95% confidence interval: 36-573). The remaining 39 were reactive radiographs, resulting in the detection of 2 (5.1%) negative sequelae with an NNS of 20 radiographs (95% confidence interval: 5-78).ConclusionsWhile radiographs remain a widely utilized tool to screen for the development of negative sequelae in pediatric osteoarticular infections, they rarely alter management in the absence of other concerning clinical signs or symptoms such as recurrent fevers, swelling of the extremity, or limb deformity. Moreover, routine radiographic surveillance should be replaced with a reactive radiographic protocol.Level of evidenceLevel III-retrospective comparative study

Lower Rates of Ceramic Femoral Head Use in Non-White Patients in the United States, a National Registry Study

BackgroundThe purpose of our study was to investigate the association of race and ethnicity with the use of the newest technology and postoperative outcomes in total hip arthroplasty (THA) using the American Academy of Orthopaedic Surgeons (AAOS) American Joint Replacement Registry (AJRR).MethodsAdult THA procedures were queried from the AJRR from 2012 to 2020. A mixed-effects multivariate regression model was used to evaluate the association of race and ethnicity with the use of the newest technology (ceramic femoral head, dual-mobility implant, and robotic assist) at 30-day, and 90-day readmission. A proportional subdistribution hazard model was used to model a risk of revision THA.ResultsThere were 85,188 THAs with complete data for an analysis of outcomes and 103,218 for an analysis of ceramic head usage. The median length of follow-up was 37.9 months (interquartile range [IQR] 21.6 to 56.3 months). In multivariate models, compared to White non-Hispanic patients, Black (odds ratio [OR] 0.79, 95% confidence interval [CI] 0.69-0.92, P < .001), Hispanic (OR 0.76, CI 0.59-0.99, P = .037), Asian (OR 0.74, CI 0.55-1.00, P = .045), and Native American (OR 0.52, CI 0.30-0.87, P = .004) patients all had significantly lower rates of ceramic head use in THA. Compared to White non-Hispanic patients, Asian (hazard ratio [HR] 0.39, CI 0.18-0.86, P = .008) and Hispanic (HR 0.43, CI 0.19-0.98, P = .043) patients had significantly lower rates of revision. No differences in 30-day or 90-day readmission rates were seen.ConclusionBlack, Hispanic, Native American, and Asian patients had lower rates of ceramic head use in THA when compared to White patients. These differences did not translate into worse clinical outcomes on a short-term follow-up. In fact, Asian patients had lower revision rates compared to non-Hispanic White patients. Additional study is necessary to evaluate the long-term consequence of lower ceramic head use in non-White patients in the United States

Long term outcomes of total humeral replacement for oncological reconstructions: A single institution experience.

BackgroundThere is a paucity of data on long-term survivorship and outcomes for total humerus replacements (THR) with only two series reporting 10-year survival.Patients and methodsA review of 769 consecutive, prospectively collected endoprosthetic reconstructions for oncological diagnoses at a single-center between 1980 and 2019 was performed. Patients with THRs were isolated and analyzed for outcomes, complications, and modes of failure.ResultsEighteen patients with 20 THR implants were identified. The median follow-up for surviving patients was 148 months (interquartile range [IQR] = 74-194) and 60 months (IQR = 17-155 months) for all patients. Two prostheses required revision for failure, both for symptomatic shoulder dislocation. There were three local recurrences. Revision-free survival at 5, 10, and 15 years was 100%, 86% and 86%, respectively. There were no cases of ulnar component failure, radial nerve palsy, or periprosthetic infection.ConclusionsTHR prosthesis survivorship is comparable to the previous series, with a longer follow-up than has previously been reported. Symptomatic shoulder instability was common (25%), and was the only cause of revision. Reverse total shoulder could be an important way to address this in the future. Local recurrence rates were high, as has been reported elsewhere for THR

Long-term follow-up of all-polyethylene tibial components when used for oncological endoprosthetic reconstruction.

AIMS:We aimed to examine the long-term mechanical survivorship, describe the modes of all-cause failure, and identify risk factors for mechanical failure of all-polyethylene tibial components in endoprosthetic reconstruction. METHODS:This is a retrospective database review of consecutive endoprosthetic reconstructions performed for oncological indications between 1980 and 2019. Patients with all-polyethylene tibial components were isolated and analyzed for revision for mechanical failure. Outcomes included survival of the all-polyethylene tibial component, revision surgery categorized according to the Henderson Failure Mode Classification, and complications and functional outcome, as assessed by the Musculoskeletal Tumor Society (MSTS) score at the final follow-up. RESULTS:A total of 278 patients were identified with 289 all-polyethylene tibial components. Mechanical survival was 98.4%, 91.1%, and 85.2% at five, ten and 15 years, respectively. A total of 15 mechanical failures were identified at the final follow-up. Of the 13 all-polyethylene tibial components used for revision of a previous tibial component, five (38.5%) failed mechanically. Younger patients (< 18 years vs > 18 years; p = 0.005) and those used as revision components (p < 0.001) had significantly increased rates of failure. Multivariate logistic regression modelling showed revision status to be a positive risk factor for failure (odds ratio (OR) 19.498, 95% confidence interval (CI) 4.598 to 82.676) and increasing age was a negative risk factor for failure (OR 0.927, 95% CI 0.872 to 0.987). Age-stratified risk analysis showed that age > 24 years was no longer a statistically significant risk factor for failure. The final mean MSTS score for all patients was 89% (8.5% to 100.0%). CONCLUSION:The long-term mechanical survivorship of all-polyethylene tibial components when used for tumour endoprostheses was excellent. Tumour surgeons should consider using these components for their durability and the secondary benefits of reduced cost and ease of removal and revision. However, caution should be taken when using all-polyethylene tibial components in the revision setting as a significantly higher rate of mechanical failure was seen in this group of patients. Cite this article: Bone Joint J. 2020;102-B(2):170-176

Long-term follow-up of all-polyethylene tibial components when used for oncological endoprosthetic reconstruction.

AIMS:We aimed to examine the long-term mechanical survivorship, describe the modes of all-cause failure, and identify risk factors for mechanical failure of all-polyethylene tibial components in endoprosthetic reconstruction. METHODS:This is a retrospective database review of consecutive endoprosthetic reconstructions performed for oncological indications between 1980 and 2019. Patients with all-polyethylene tibial components were isolated and analyzed for revision for mechanical failure. Outcomes included survival of the all-polyethylene tibial component, revision surgery categorized according to the Henderson Failure Mode Classification, and complications and functional outcome, as assessed by the Musculoskeletal Tumor Society (MSTS) score at the final follow-up. RESULTS:A total of 278 patients were identified with 289 all-polyethylene tibial components. Mechanical survival was 98.4%, 91.1%, and 85.2% at five, ten and 15 years, respectively. A total of 15 mechanical failures were identified at the final follow-up. Of the 13 all-polyethylene tibial components used for revision of a previous tibial component, five (38.5%) failed mechanically. Younger patients (< 18 years vs > 18 years; p = 0.005) and those used as revision components (p < 0.001) had significantly increased rates of failure. Multivariate logistic regression modelling showed revision status to be a positive risk factor for failure (odds ratio (OR) 19.498, 95% confidence interval (CI) 4.598 to 82.676) and increasing age was a negative risk factor for failure (OR 0.927, 95% CI 0.872 to 0.987). Age-stratified risk analysis showed that age > 24 years was no longer a statistically significant risk factor for failure. The final mean MSTS score for all patients was 89% (8.5% to 100.0%). CONCLUSION:The long-term mechanical survivorship of all-polyethylene tibial components when used for tumour endoprostheses was excellent. Tumour surgeons should consider using these components for their durability and the secondary benefits of reduced cost and ease of removal and revision. However, caution should be taken when using all-polyethylene tibial components in the revision setting as a significantly higher rate of mechanical failure was seen in this group of patients. Cite this article: Bone Joint J. 2020;102-B(2):170-176

Severity and location of lumbar spine stenosis affects the outcome of total knee arthroplasty.

BackgroundRecent studies have noted that patients with pre-existing lumbar spinal stenosis (LSS) have lower functional outcomes after total knee arthroplasty (TKA). Given that LSS manifests heterogeneously in location and severity, its influence on knee replacement merits a radiographically targeted analysis. We hypothesize that patients with more severe LSS will have diminished knee mobility before and after TKA.MethodsThis retrospective case series assessed all TKAs performed at our institution for primary osteoarthritis from 2017-2020. Preoperative lumbar magnetic resonance image (MRI) with no prior lumbar spine surgery was necessary for inclusion. Stenosis severity was demonstrated by (1) anterior-posterior (AP) diameter of the thecal sac and (2) morphological grade. TKA outcomes in 103 cases (94 patients) were assessed by measuring preoperative and postoperative arc of motion (AOM), postoperative flexion contracture, and need for manipulation under anesthesia.ResultsPatients with mild stenosis did significantly better in terms of postoperative knee AOM. As AP diameter decreased at levels L1-2, L2-3, L3-4, and L4-5, there was a significant reduction in preoperative-AOM (p < 0.001 for each), with a 16 degree decrease when using patients' most stenotic level (p < 0.001). The same was noted with respect to increased morphological grade (p < 0.001), with a 5 degree decrease for patients' most stenotic level (p < 0.001).ConclusionSevere LSS, which is readily demonstrated by a reduction in the AP diameter of the thecal sac or increased morphological grade on MRI, correlated with a significant reduction in preoperative AOM that was not improved after TKA. Persistent postoperative reductions in AOM may contribute to reduced patient satisfaction and recovery.Level of evidenceLevel 4