Osteoporosis and cement usage in total hip arthroplasty.

PURPOSE: Cement usage in total hip arthroplasty (THA) is increasingly common. However, osteoporosis-related fracture risk in cemented vs uncemented THA patients is poorly characterized. We aim to analyze the usage of metabolic bone care and osteoporosis fracture risk in cemented vs uncemented THA patients using FRAX and radiographic bone measurements. METHODS: Chart review on 250 THA patients was performed retrospectively. Demographics, FRAX scores, hip radiograph measurements, osteoporosis diagnosis, treatment and screening were compared between cemented and uncemented THA patients. Logistic regression model was used to analyze factors influencing cement usage. RESULTS: Cemented THA patients have significantly higher osteoporosis-related fracture risk as measured by FRAX major (20% vs 13%) and FRAX hip (8% vs 5%). There is no significant difference in osteoporosis treatment, vitamin D / calcium supplementation, or metabolic bone disease screening based on patients' cement status. Female sex and rheumatoid arthritis status significantly predict cement usage, but FRAX scores do not predict cement usage. Additionally, 50% (10/20) of patients with Dorr C classification were uncemented. CONCLUSION: Although some patients undergoing THA with high osteoporosis-related fracture risk were identified and cemented, some risk factors including poor proximal femur shape (by Dorr classification) and poor bone quality (as measured by FRAX score) were potentially overlooked. Cemented patients had an increased risk for fractures but did not receive appropriately increased osteoporosis screening or treatment. LEVEL OF EVIDENCE: III.

The Effect of Social Isolation on 1-Year Outcomes After Surgical Repair of Low-Energy Hip Fracture.

OBJECTIVES: To evaluate whether social isolation or loneliness is associated with outcomes 1 year after low-energy hip fracture. DESIGN: Prospective inception cohort study. SETTING: Academic level I trauma center. PATIENT SELECTION CRITERIA: Participants were 65 years or older and enrolled 2-4 days after surgery for a first low-energy hip fracture. Exclusion criteria were bilateral or periprosthetic hip fracture, previous hip fracture, non-English speaking, international address, active cancer, stage 4 cancer in the past 5 years, radiation to the hip region, and cognitive impairment. Participants were followed longitudinally for 1 year. OUTCOME MEASURES AND COMPARISONS: The patient-reported outcomes measurement information system (PROMIS)-29 was elicited 2-4 days postoperatively and 1 year later. Patient-reported risk factors included the Lubben Social Networks Scale and the University of California, Los Angeles Loneliness Scale, which were compared with the lower extremity activity scale and PROMIS-29 domains. RESULTS: Three hundred and twenty-five patients were enrolled. Participants had a median age of 81.7 years, were 70.9% female, and were 85.9% White. In total, 31.6% of patients were socially isolated at the time of fracture. At 1 year, 222 of the 291 subjects who were confirmed alive at 1 year provided data. Multivariable linear models were performed separately for each outcome, including lower extremity activity scale and PROMIS-29 domains. Controlling for age, sex, education, and body mass index, those who were socially isolated at the time of fracture had worse PROMIS-29 function (ß = -3.83; P = 0.02) and ability to participate in social roles (ß = -4.17; P = 0.01) at 1 year. Secondary analyses found that prefracture loneliness was associated with clinically meaningfully worse function, anxiety, depression, fatigue, sleep, pain, and ability to participate in social roles at 1 year (all P < 0.01). CONCLUSIONS: Prefracture social isolation was associated with worse outcomes 1 year after surgical repair of low-energy hip fracture. These data suggest loneliness may be more strongly associated with important patient-centric metrics than prefracture social isolation. Given the dearth of modifiable risk factors in this population, future studies are needed to evaluate whether improving social connections could affect outcomes in this rapidly growing demographic. LEVEL OF EVIDENCE: Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Atmospheric Gas-Phase Formation of Methanesulfonic Acid.

Despite its impact on the climate, the mechanism of methanesulfonic acid (MSA) formation in the oxidation of dimethyl sulfide (DMS) remains unclear. The DMS + OH reaction is known to form methanesulfinic acid (MSIA), methane sulfenic acid (MSEA), the methylthio radical (CH3S), and hydroperoxymethyl thioformate (HPMTF). Among them, HPMTF reacts further to form SO2 and OCS, while the other three form the CH3SO2 radical. Based on theoretical calculations, we find that the CH3SO2 radical can add O2 to form CH3S(O)2OO, which can react further to form MSA. The branching ratio is highly temperature sensitive, and the MSA yield increases with decreasing temperature. In warmer regions, SO2 is the dominant product of DMS oxidation, while in colder regions, large amounts of MSA can form. Global modeling indicates that the proposed temperature-sensitive MSA formation mechanism leads to a substantial increase in the simulated global atmospheric MSA formation and burden.

A clinical prediction model for 10-year risk of self-reported osteoporosis diagnosis in pre- and perimenopausal women.

A machine learning model using clinical, laboratory, and imaging data was developed to predict 10-year risk of menopause-related osteoporosis. The resulting predictions, which are sensitive and specific, highlight distinct clinical risk profiles that can be used to identify patients most likely to be diagnosed with osteoporosis. PURPOSE: The aim of this study was to incorporate demographic, metabolic, and imaging risk factors into a model for long-term prediction of self-reported osteoporosis diagnosis. METHODS: This was a secondary analysis of 1685 patients from the longitudinal Study of Women's Health Across the Nation using data collected between 1996 and 2008. Participants were pre- or perimenopausal women between 42 and 52 years of age. A machine learning model was trained using 14 baseline risk factors-age, height, weight, body mass index, waist circumference, race, menopausal status, maternal osteoporosis history, maternal spine fracture history, serum estradiol level, serum dehydroepiandrosterone level, serum thyroid-stimulating hormone level, total spine bone mineral density, and total hip bone mineral density. The self-reported outcome was whether a doctor or other provider had told participants they have osteoporosis or treated them for osteoporosis. RESULTS: At 10-year follow-up, a clinical osteoporosis diagnosis was reported by 113 (6.7%) women. Area under the receiver operating characteristic curve of the model was 0.83 (95% confidence interval, 0.73-0.91) and Brier score was 0.054 (95% confidence interval, 0.035-0.074). Total spine bone mineral density, total hip bone mineral density, and age had the largest contributions to predicted risk. Using two discrimination thresholds, stratification into low, medium, and high risk, respectively, was associated with likelihood ratios of 0.23, 3.2, and 6.8. At the lower threshold, sensitivity was 0.81, and specificity was 0.82. CONCLUSION: The model developed in this analysis integrates clinical data, serum biomarker levels, and bone mineral densities to predict 10-year risk of osteoporosis with good performance.

Reaction of Atmospherically Relevant Sulfur-Centered Radicals with RO2 and HO2.

The atmospheric oxidation of dimethyl sulfide and other emitted sulfur species leads to the formation of the methylthio radical, CH3S, which can be further oxidized to the CH3SO and CH3SO2 radicals. We investigated computationally the reactions of these three sulfur-centered radicals with the peroxy radicals ROO and HOO. Our results demonstrate that CH3S and CH3SO react with these peroxy radicals to form short-lived peroxide intermediates, which then decompose via a concerted O-O bond scission and S═O double bond formation that results in an increased valence of the sulfur atom. In contrast, CH3SO2 reacts to form stable CH3S(O)2OOR and CH3S(O)2OOH peroxide products, as sulfur is already at its highest valence. Multireference methods were used to describe these reactions in which the valence of the sulfur atom changes.

Bone loss after denosumab discontinuation is prevented by alendronate and zoledronic acid but not risedronate: a retrospective study.

A retrospective study of 121 patients who stopped denosumab (Dmab) then received no treatment (NT), risedronate (RIS), alendronate (ALN), or zoledronic acid (ZOL). Bone density (spine and hip) during and after Dmab discontinuation was measured. Treatment with ALN or ZOL, not NT and RIS, mitigated BMD loss after Dmab discontinuation. INTRODUCTION: Denosumab (Dmab) discontinuation is associated with bone loss and multiple vertebral fractures. The purpose was to compare bone mineral density (BMD) change in patients following Dmab discontinuation with no subsequent treatment (NT) and three bisphosphonate (BP) treatments: risedronate (RIS), alendronate (ALN), and zoledronic acid (ZOL). METHODS: In a review of 121 patients aged 71.2 ± 8.1 years, discontinuing Dmab (mean 5.4 doses), 33 received NT and 88 received BP (22 RIS; 34 ALN; 32 ZOL). BMD change after 1 year was compared between groups at the lumbar spine (LS), femoral neck (FN), and total hip (TH). Risk factors for bone loss after Dmab discontinuation were compared between groups and incidence of vertebral fractures was determined. RESULTS: Following Dmab discontinuation, LS mean change (g/cm2; 95% CI) was for NT: - 0.041 (- 0.062 to - 0.021); RIS: - 0.035 (- 0.052 to - 0.017); ALN: - 0.005 (- 0.020 to 0.009); and ZOL: - 0.009 (- 0.025 to 0.008). Differences in LS were found between NT and ALN (p =  0.015), and NT and ZOL (p=0.037), but not between NT and RIS. The only significant difference in TH was found between NT and ZOL (p 0.034) with no group differences in FN. BMD gains during Dmab treatment were associated with BMD loss after Dmab discontinuation. In a subset, discontinuation after Dmab treatment (> 5 doses) followed by ALN (n = 22) and ZOL (n = 11) showed no difference in BMD. Five of 7 vertebral fractures occurred after Dmab discontinuation in NT. CONCLUSION: Subsequent treatment with ALN or ZOL but not NT and RIS mitigates BMD loss after Dmab discontinuation.

Chronic Warfarin Anticoagulation in Hip Fracture Patients Delays Surgery and Is Associated With Increased Risk of Postoperative Complications: A Multicenter Propensity-Score-Matched Analysis.

OBJECTIVE: To evaluate the effect of warfarin on blood transfusion and postoperative complications in a low-energy hip fracture population compared with a non-anticoagulated comparison group. DESIGN: Multicenter Retrospective Cohort. SETTING: Three Urban Level I Academic Trauma Centers. PATIENTS: Acute, low-energy, native hip fractures in patients 55 years of age or older on chronic warfarin anticoagulation, propensity score matched 1:2 to non-anticoagulated hip fracture patients meeting all other inclusion criteria. MAIN OUTCOME MEASUREMENTS: Transfusion and postoperative complication rates. RESULTS: Two hundred ten anticoagulated hip fracture patients were matched to 420 nonanticoagulated patients. A higher proportion of patients required blood transfusion in the warfarin cohort (52.4% vs. 43.3%, P < 0.001), attributable mostly to the subgroup of patients undergoing arthroplasty. Warfarin patients had higher incidence of overall 90-day complications (47% vs. 38%, P = 0.039) and readmissions (31.4% vs. 8.9%, P < 0.001). Day of surgery international normalized ratio (INR) did not influence transfusions or complications among warfarin patients. Warfarin patients undergoing surgery within 24 hours had no difference in transfusions and had fewer complications compared with those undergoing surgery after 24 hours. On multivariable logistic regression analysis, warfarin use and day of surgery INR were not predictors of transfusion or complications. CONCLUSIONS: Patients on warfarin experienced longer time to surgery and higher incidence of overall transfusion and postoperative complications within 90 days of surgery. However, warfarin use and day of surgery INR was not independently associated with transfusions or complications. The reason for poorer outcomes in warfarin patients remains a topic of further investigation. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Against the Norm: Non Irving-Williams Transmetalation in Transition Metal Dimers.

We report the synthesis and characterization of three dinuclear 3d3d' complexes, CuCu ([Cu2IIL(NO3)2]), MnMn ([Mn2IIL(MeOH)2(NO3)2]), and CuMn ([CuIIMnIIL(NO3)2]), that utilize the ligand, H2L (6,6'-dimethoxy-2,2'-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol). The relative stabilities of these complexes were investigated using experimental and computational techniques, revealing a non-Irving-Williams transmetalation, whereby a MnII ion can displace a CuII ion from its binding pocket in CuCu to yield the more stable CuMn complex. Magnetic characterization of the reported complexes revealed an unexpected ferromagnetic coupling between the two CuII ions of CuCu with J = +63.0 cm-1.

Nonunion of the Coracoid Base Secondary to Cutibacterium acnes Infection in a Surgically Naive Patient: A Case Report.

CASE: We present the case of a 42-year-old man with a coracoid base fracture that progressed to nonunion. The patient underwent percutaneous autologous bone-marrow and demineralized bone matrix (DBM) grafting 8 months after injury, with all intraoperative cultures positive for Cutibacterium acnes. The patient had no prior surgeries, but he began shaving his axillae around the time of injury. He was treated with amoxicillin; by the 6-week follow-up, computed tomography demonstrated complete fracture healing. CONCLUSION: Our case demonstrates a novel etiology of coracoid nonunion treated successfully by eradicating the infection with biologic augmentation by percutaneous autologous bone-marrow grafting with DBM and oral antibiotics.

Fracture Risk Assessment Tool Scores and Radiographical Bone Measurements in Total Hip Arthroplasty Patients.

BACKGROUND: Osteoporosis is a major risk factor for periprosthetic fractures (PPFx) in total hip arthroplasty (THA) patients but is not routinely screened for in this population. Given the availability of hip x-rays and preoperative screenings, Fracture Risk Assessment Tool (FRAX) scores and radiographic bone measurements are potentially promising, novel risk stratification tools. This study aims to characterize FRAX scores and radiographic bone measurements in THA and PPFx patients. METHODS: A retrospective chart review for demographic variables and FRAX scores was performed on 250 THA and 40 PPFx patients. Radiographic bone measurements including cortical thicknesses (both antero-posterior [AP] and lateral), canal to calcar ratio, canal flare index, and Dorr classifications were obtained from preoperative x-rays. Correlation between FRAX scores and radiographic bone measurements was investigated with linear regressions. FRAX scores and radiographic bone measurements were compared between the THA and PPFx patients. Multivariate logistic regressions were used to identify factors predicting PPFx. RESULTS: FRAX scores were significantly correlated with both AP (P < .001) and lateral (P = .007) cortical thicknesses. Compared to THA patients, those with PPFx had significantly higher FRAX scores (P = .003) and lower AP cortical thickness (P = .005). Multivariate logistic regressions demonstrated that FRAX major osteoporotic fracture risk score and AP cortical thickness were independent predictors of PPFx (P = .001 and .024, respectively). CONCLUSION: Cortical thicknesses are good proxy measurements of osteoporosis-related fracture risk in THA patients. In addition, both major and AP cortical thickness indices are promising tools for identifying patients who are at a high risk of PPFx in the THA population.

Osteonecrosis of the Femoral Head.

Osteonecrosis of the femoral head is a progressive and debilitating condition with a wide variety of etiologies including trauma, steroid use, and alcohol intake. Diagnosis and staging are based on imaging including MRI at any stage and plain radiography in more advanced lesions. The only definitive treatment is total hip arthroplasty, although numerous treatments including disphosphonates and core decompression are used to delay the progression. Lack of satisfactory conservative measures suggests the need for additional research of osteonecrosis including large patient registries to further understand this condition.

Epidural Steroid Injections Acutely Suppress Bone Formation Markers in Postmenopausal Women.

CONTEXT: Over 9 million epidural steroid injections (ESIs) are performed annually in the United States. Although these injections effectively treat lumbar radicular pain, they may have adverse consequences, including bone loss. OBJECTIVE: To investigate acute changes in bone turnover following ESI. We focused on postmenopausal women, who may be at greatest risk for adverse skeletal consequences due to the combined effects of ESIs with aging and estrogen deficiency. METHODS: Single-center prospective observational study. Postmenopausal women undergoing lumbar ESIs and controls with no steroid exposure were included. Outcomes were serum cortisol, markers of bone formation, osteocalcin, and procollagen type-1 N-terminal propeptide (P1NP), and bone resorption by C-telopeptide (CTX) measured at baseline, 1, 4, 12, 26, and 52 weeks after ESIs. RESULTS: Among ESI-treated women, serum cortisol declined by ~50% 1 week after injection. Bone formation markers significantly decreased 1 week following ESIs: osteocalcin by 21% and P1NP by 22%. Both markers remained suppressed at 4 and 12 weeks, but returned to baseline levels by 26 weeks. There was no significant change in bone resorption measured by CTX. Among controls, there were no significant changes in cortisol or bone turnover markers. CONCLUSION: These results provide evidence of an early and substantial reduction in bone formation markers following ESIs. This effect persisted for over 12 weeks, suggesting that ESIs may have lasting skeletal consequences. Given the large population of older adults who receive ESIs, further investigation into the long-term skeletal sequelae of these injections is warranted.

Total Joint Arthroplasty and Osteoporosis: Looking Beyond the Joint to Bone Health.

BACKGROUND: Metabolic bone diseases in the total joint arthroplasty (TJA) population are undertested and undertreated, leading to increased risk of adverse outcomes such as periprosthetic fractures. This study aims to better characterize the current state of bone care in TJA patients using Fracture Risk Assessment Tool (FRAX) score risk stratifications. METHODS: In total, 505 consecutive TJA patients who meet the Endocrine Society guidelines for osteoporosis screening were included for review. They were divided into a high risk or low risk group depending on FRAX scores and were compared based on screening, diagnosis, and treatment of metabolic bone disease. Logistic regression models were used to analyze factors influencing screening and treatment. A population analysis involving 2,000 TJA patients, and a complication analysis involving 40 periprosthetic fracture patients were conducted. RESULTS: Among high risk patients undergoing TJA, 90% did not receive any pharmacological treatment for osteoporosis, 45% were not treated with vitamin D or calcium, and 88% did not receive bone density testing in the routine care period. Among patients with pre-existing osteoporosis undergoing TJA, 80% were not treated with any osteoporosis medications and 33% of these patients were not taking vitamin D or calcium. Female gender and past fracture history contributed to whether patients received screening and treatment. Patients with periprosthetic hip fractures have significantly higher FRAX scores compared to control THA patients. CONCLUSION: There are significant gaps in metabolic bone care of the geriatric TJA population regarding both screening and treatment. Metabolic bone care and risk identification with FRAX should be highly considered for TJA patients.

Conceptualizing Biological Aging and Frailty in Orthopaedics: A Framework for Clinical Practice.

➤: Biological aging can best be conceptualized clinically as a combination of 3 components: frailty, comorbidity, and disability. ➤: Despite advancements in the understanding of senescence, chronological age remains the best estimate of biological age. However, a useful exercise for practitioners is to look beyond chronological age in clinical and surgical decision-making. ➤: A chronologically aging person does not age biologically at the same rate. ➤: The best way to understand frailty is to consider it as a physical phenotype. ➤: Physical optimization should parallel medical optimization before elective surgery. ➤: The poorer the host (both in terms of bone quality and propensity for healing), the more robust the implant construct must be to minimize reliance on host biology.

Delayed Surgery Does Not Reduce Transfusion Rates in Low-Energy Hip Fractures on Direct Oral Anticoagulants.

OBJECTIVES: To compare transfusion rates in patients on direct oral anticoagulants (DOACs) with nonanticoagulated patients undergoing hip fracture surgery and, secondarily, to determine whether time to surgery or complications differ between these groups. DESIGN: Multicenter retrospective cohort. SETTING: Three tertiary care, academic, Level I trauma centers. PATIENTS: Acute, operatively treated, low-energy hip fracture patients 55 years of age and older were included. Anticoagulated patients were matched in a 1:2 ratio to "control" nonanticoagulated hip fracture patients using propensity score matching. MAIN OUTCOME MEASUREMENTS: The primary outcome was incidence of perioperative transfusion. The secondary outcomes included time to surgery, length of stay, and 90-day complications, readmissions, reoperations, and mortality. RESULTS: One hundred thirty-two patients with hip fracture admitted on DOACs were identified (107 factor Xa inhibitors, 25 dabigatran) and were matched to 262 "control" nonanticoagulated patients. There was no difference in overall transfusion rates between anticoagulation and control groups (43.2%; n = 57 DOAC vs. 39.7%; n = 104 control; P = 0.517). The median time from admission to surgery was 41.7 hours in the DOAC group and 26.0 hours in the control group (P < 0.001). There were no differences in 90-day complication, readmission, reoperation, or mortality rates between DOAC and control groups. Comparing DOAC patients undergoing surgery within 24 hours and after 24 hours, there were no differences in transfusion rates (P = 0.558) or overall complication rates (P = 0.179). CONCLUSIONS: This study supports growing evidence that DOAC use should not be a determining factor in delaying surgery for patients with hip fracture who are otherwise medically optimized. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Comparison of Risks and Benefits Regarding Hip Arthroplasty Fixation.

Since the field-changing invention of noncemented hip arthroplasty fixation in the 1980s, noncemented fixation has been progressively replacing cemented fixation. However, analyses of fixation frequencies reveal new patterns in cement versus noncemented preferences. Although cementation is again gaining ground in the United States, noncemented models remain the dominant fixation mode, seen in more than 90% of all hip arthroplasties. This stark preference is likely driven by concerns regarding implant durability and patient safety. Although advances in surgical techniques, intensive perioperative care, and improved instrument have evolved in both methods, data from large arthroplasty registries reveal shifting risks in contemporary hip arthroplasty, calling the use of noncemented fixation into question. Varying risk profiles regarding sex, age, or health comorbidities and morphological and functional differences necessitate personalized risk assessments. Furthermore, certain patient populations, based on the literature and data from large registries, have superior outcomes from cemented hip arthroplasty techniques. Therefore, we wanted to critically evaluate the method of arthroplasty fixation in primary hip arthroplasties for unique patient populations.