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.

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.

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.

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.

Comprehensive phenotyping of erythropoiesis in human bone marrow: Evaluation of normal and ineffective erythropoiesis.

Identification of stage-specific erythroid cells is critical for studies of normal and disordered human erythropoiesis. While immunophenotypic strategies have previously been developed to identify cells at each stage of terminal erythroid differentiation, erythroid progenitors are currently defined very broadly. Refined strategies to identify and characterize BFU-E and CFU-E subsets are critically needed. To address this unmet need, a flow cytometry-based technique was developed that combines the established surface markers CD34 and CD36 with CD117, CD71, and CD105. This combination allowed for the separation of erythroid progenitor cells into four discrete populations along a continuum of progressive maturation, with increasing cell size and decreasing nuclear/cytoplasmic ratio, proliferative capacity and stem cell factor responsiveness. This strategy was validated in uncultured, primary erythroid cells isolated from bone marrow of healthy individuals. Functional colony assays of these progenitor populations revealed enrichment of BFU-E only in the earliest population, transitioning to cells yielding BFU-E and CFU-E, then CFU-E only. Utilizing CD34/CD105 and GPA/CD105 profiles, all four progenitor stages and all five stages of terminal erythroid differentiation could be identified. Applying this immunophenotyping strategy to primary bone marrow cells from patients with myelodysplastic syndrome, identified defects in erythroid progenitors and in terminal erythroid differentiation. This novel immunophenotyping technique will be a valuable tool for studies of normal and perturbed human erythropoiesis. It will allow for the discovery of stage-specific molecular and functional insights into normal erythropoiesis as well as for identification and characterization of stage-specific defects in inherited and acquired disorders of erythropoiesis.

Rationale for Bone Health Optimization in Patients Undergoing Orthopaedic Surgery.

Osteoporosis is common, affecting more than 40 million people, and is associated with increased fracture risk, loss of independence, chronic pain, and disability. Osteoporosis is underdiagnosed and undertreated even after fracture where secondary fracture prevention has been shown to be cost effective in reducing further fracture risk and mortality. Osteoporosis is also undiagnosed in patients undergoing orthopaedic and spine surgery in up to one-third of cases and negatively affects outcomes, need for revision surgery, and risk of complications. The diagnosis of osteoporosis was previously based on bone mineral density; however, recent clinical definitions include T-scores less than -2.5, the presence of hip and spine fractures, and high fracture risk. Surgeons should adopt bone health optimization for elective surgery. This program screens patients to determine whether a bone mineral density test is indicated and provides counseling for nutritional supplements, elimination of toxins, fall risk assessment, and education regarding bone health. Following assessment, patients meeting the criteria for osteoporosis are referred to a bone health specialist or a fracture liaison program. Both antiresorptive and anabolic antiosteoporotic medications appear effective at improving outcomes and reducing complications of orthopaedic and spine surgery, although a delay in surgery may be required.

The Basics of Bone Physiology, Healing, and Osteoporosis.

Osteoporosis is a skeletal condition characterized by decreased bone mineral density and poor bone quality with resultant greater fracture risk. There has been a focus on bone mineral density deficiency, which is easily measured with dual-energy x-ray absorptiometry and managed with pharmaceutic medications. More recently, impaired bone quality independent of bone mineral density has been recognized as a potential cause of fragility fracture and poor bone healing. Many conditions lead to poor bone quality; the most common is vitamin D deficiency and others are genetic causes and other nutritional deficits. In addition, the cellular and molecular changes associated with osteoporosis are being investigated and are potential targets for treatment. Treatment of patients with poor bone health include nutritional supplementation with vitamin D and calcium, weight-bearing exercises, and antiosteoporotic medications when warranted. Antiosteoporotic medications include antiresorptive drugs such as diphosphonate and denosumab that inhibit osteoclastic bone resorption. Anabolic agents such as teriparatide, abaloparatide, and romosozumab stimulate osteoblastic differentiation and bone formation. All these agents are effective in reducing fracture risk.

Prediction of Long Bone Fractures in Multiple Myeloma Patients in an Advanced Imaging World.

BACKGROUND: Multiple myeloma (MM) affects the long bones in 25% of patients. The advent of positron-emission tomography/computed tomography (PET/CT) scanners offers the possibility of both metabolic and radiographic information and may help determine fracture risk. To the best of our knowledge, no published study correlates these two factors with long bone fractures. OBJECTIVES: To evaluate the impact of PET/CT on fracture risk assessment in multiple myeloma patients. METHODS: We identified all bone marrow biopsy proven multiple myeloma patients from 1 January 2010 to 31 January 2015 at a single institution. We prospectively followed patients with long bone lesions using PET/CT scan images. RESULTS: We identified 119 patients (59 males/60 females) with 256 long bone lesions. Mean age at diagnosis was 58 years. The majority of lesions were in the femur (n=150, 59%) and humerus (n=84, 33%); 13 lesions in 10 patients (8%) required surgery for impending (n=4) or actual fracture (n=9). Higher median SUVmax was measured for those with cortical involvement (8.05, range 0-50.8) vs. no involvement (5.0, range 2.1-18.1). SUVmax was found to be a predictor of cortical involvement (odds ratio = 1.17, P = 0.026). No significant correlation was found between SUVmax and pain or fracture (P = 0.43). CONCLUSIONS: Improved medical treatment resulted improvement in 8% of patients with an actual or impending fracture. The orthopedic surgeons commonly use the Mirels classification for long bone fracture prediction. Adding PET/CT imaging to study in myeloma long bone lesions did not predict fracture risk directly but suggested it indirectly by cortical erosion.

Atypical fracture with long-term bisphosphonate therapy is associated with altered cortical composition and reduced fracture resistance.

Bisphosphonates are the most widely prescribed pharmacologic treatment for osteoporosis and reduce fracture risk in postmenopausal women by up to 50%. However, in the past decade these drugs have been associated with atypical femoral fractures (AFFs), rare fractures with a transverse, brittle morphology. The unusual fracture morphology suggests that bisphosphonate treatment may impair toughening mechanisms in cortical bone. The objective of this study was to compare the compositional and mechanical properties of bone biopsies from bisphosphonate-treated patients with AFFs to those from patients with typical osteoporotic fractures with and without bisphosphonate treatment. Biopsies of proximal femoral cortical bone adjacent to the fracture site were obtained from postmenopausal women during fracture repair surgery (fracture groups, n = 33) or total hip arthroplasty (nonfracture groups, n = 17). Patients were allocated to five groups based on fracture morphology and history of bisphosphonate treatment [+BIS Atypical: n = 12, BIS duration: 8.2 (3.0) y; +BIS Typical: n = 10, 7.7 (5.0) y; +BIS Nonfx: n = 5, 6.4 (3.5) y; -BIS Typical: n = 11; -BIS Nonfx: n = 12]. Vibrational spectroscopy and nanoindentation showed that tissue from bisphosphonate-treated women with atypical fractures was harder and more mineralized than that from bisphosphonate-treated women with typical osteoporotic fractures. In addition, fracture mechanics measurements showed that tissue from patients treated with bisphosphonates had deficits in fracture toughness, with lower crack-initiation toughness and less crack deflection at osteonal boundaries than that of bisphosphonate-naïve patients. Together, these results suggest a deficit in intrinsic and extrinsic toughening mechanisms, which contribute to AFFs in patients treated with long-term bisphosphonates.

Operative Fixation of Hip Fractures in Nonagenarians: Is It Safe?

BACKGROUND: With the shift in hip fracture epidemiology toward older individuals as well as the shift in demographics toward nonagenarians, it is important to understand the outcomes of treatment for these patients. METHODS: Geriatric patients (≥65 years old) who underwent surgery for hip fracture were identified in the 2005-2017 National Surgical Quality Improvement Program database and stratified into 2 age groups: <90 and ≥90 years old (nonagenarians). Preoperative and procedural characteristics were compared. Multivariate regressions were used to compare risk for complications and 30-day readmissions. Risk factors for serious adverse events (SAEs) and 30-day mortality in nonagenarians were characterized. RESULTS: This study included 51,327 <90 year olds and 15,798 nonagenarians. Overall rate of SAEs in nonagenarians was 19.89% while in <90 year olds was 14.80%. Multivariate analysis revealed higher risk for blood transfusion (relative risk [RR] = 1.21), death (RR = 1.74), pneumonia (RR = 1.24), and cardiac complications (RR = 1.33) in nonagenarians (all P < .001). Risk factors for SAEs in nonagenarians include American Society of Anesthesiologists ≥3, dependent functional status, admitted from nursing home/chronic/intermediate care, preoperative hypoalbuminemia, and male gender (all P < .05), but not time to surgery (P > .05). In fact, increased time to surgery in nonagenarians was associated with lower risk of 30-day mortality (RR = 0.90, P = .048). CONCLUSION: Overall complication risk after hip fracture fixation in nonagenarians remains relatively low but higher than their younger counterparts. Interestingly, since time to surgery was not associated with adverse outcomes in nonagenarians, the commonly accepted 48-hour operative window may not be critical to this population. Additional time for preoperative medical optimization in this vulnerable population appears prudent.

The Frank Stinchfield Award : Total Hip Arthroplasty for Femoral Neck Fracture Is Not a Typical DRG 470: A Propensity-matched Cohort Study.

BACKGROUND: Hip fractures are a major public health concern. For displaced femoral neck fractures, the needs for medical services during hospitalization and extending beyond hospital discharge after total hip arthroplasty (THA) may be different than the needs after THA performed for osteoarthritis (OA), yet these differences are largely uncharacterized, and the Medicare Severity Diagnosis-Related Groups system does not distinguish between THA performed for fracture and OA. QUESTIONS/PURPOSES: (1) What are the differences in in-hospital and 30-day postoperative clinical outcomes for THA performed for femoral neck fracture versus OA? (2) Is a patient's fracture status, that is whether or not a patient has a femoral neck fracture, associated with differences in in-hospital and 30-day postoperative clinical outcomes after THA? METHODS: The National Surgical Quality Improvement Program (NSQIP) database, which contains outcomes for surgical patients up to 30 days after discharge, was used to identify patients undergoing THA for OA and femoral neck fracture. OA and fracture cohorts were matched one-to-one using propensity scores based on age, gender, American Society of Anesthesiologists grade, and medical comorbidities. Propensity scores represented the conditional probabilities for each patient having a femoral neck fracture based on their individual characteristics, excluding their actual fracture status. Outcomes of interest included operative time, length of stay (LOS), complications, transfusion, discharge destination, and readmission. There were 42,692 patients identified (41,739 OA; 953 femoral neck fractures) with 953 patients in each group for the matched analysis. RESULTS: For patients with fracture, operative times were slightly longer (98 versus 92 minutes, p = 0.015), they experienced longer LOS (6 versus 4 days, p < 0.001), and the overall frequency of complications was greater compared with patients with OA (16% versus 6%, p < 0.001). Although the frequency of preoperative transfusions was higher in the fracture group (2.0% versus 0.2%, p = 0.002), the frequency of postoperative transfusion was not different between groups (27% versus 24%, p = 0.157). Having a femoral neck fracture versus OA was strongly associated with any postoperative complication (odds ratio [OR], 2.8; 95% confidence interval [CI], 2.1-3.8]; p < 0.001), unplanned readmission (OR, 1.8; 95% CI, 1.0-3.2; p = 0.049), and discharge to an inpatient facility (OR, 1.7; 95% CI, 1.4-2.0; p < 0.001). CONCLUSIONS: Compared with THA for OA, THA for femoral neck fracture is associated with greater rates of complications, longer LOS, more likely discharge to continued inpatient care, and higher rates of unplanned readmission. This implies higher resource utilization for patients with a fracture. These differences exist despite matching of other preoperative risk factors. As healthcare reimbursement moves toward bundled payment models, it would seem important to differentiate patients and procedures based on the resource utilization they represent to healthcare systems. These results show different expected resource utilization in these two fundamentally different groups of patients undergoing hip arthroplasty, suggesting a need to modify healthcare policy to maintain access to THA for all patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

Low Vitamin D Levels are Associated With Need for Surgical Correction of Pediatric Fractures.

BACKGROUND: There is growing concern over the relationship between the severity of pediatric fractures and low vitamin D [25-hydroxyvitaminD (25(OH)D)] status. OBJECTIVE: Compare 25(OH)D levels and lifestyle of children with fractures to nonfracture controls to determine if 25(OH)D levels are associated with fractures and if there is a 25(OH)D fragility fracture threshold. METHODS: Pediatric fracture and nonfracture controls were included. Bone health survey and medical record data were analyzed. Fractures were categorized using the Abbreviated Injury Scale (AIS). AIS 3 fractures were identified as fractures that required surgical intervention. Univariate and multivariable ordinal regression analyses were performed to identify potential risk factors for increased fracture severity. RESULTS: A total of 369 fracture patients and 662 nonfracture controls aged 18 years and younger were included. Both groups' 25(OH)D levels were comparable. 25(OH)D was 27.5±8.9 in the fracture group compared with 27.4±9.1 ng/mL in nonfracture controls (P=0.914). AIS 3 fractures had lower 25(OH)D levels (24.6±9.3 ng/mL) versus AIS 1 and 2 (30.0±10.8 and 28.3±8.4, respectively, P=0.001). Univariate correlations for AIS severity were found with age (P=0.015) and outdoor playtime (P=0.042). Adjusted odds ratios for 25(OH)D levels <12 ng/mL was 55.4 (P=0.037), 25(OH)D between 12 and 20 ng/mL was 6.7 (P=0.039), 25(OH)D between 20 and 30 ng/mL was 2.8 (P=0.208), and 25(OH)D between 30 and 40 was 1.7 (P=0.518). CLINICAL RELEVANCE: Occurrence of a pediatric fracture was not associated with 25(OH)D levels in our study. However, children with lower vitamin D levels were found to be at higher risk for more severe fractures. Early evidence suggests that the target serum level for 25(OH)D should be at least 40 ng/mL in patients less than 18 years of age as the relative risk of more severe fractures increased as 25(OH)D levels decreased <40 ng/mL. LEVEL OF EVIDENCE: Level III.

Variation in Resource Utilization for Patients With Hip and Pelvic Fractures Despite Equal Medicare Reimbursement.

BACKGROUND: Medicare currently reimburses hospitals for inpatient admissions with "bundled" payments based on patient Diagnosis-related Groups (DRGs) regardless of true hospital costs. At present, DRG 536 (fractures of the hip and pelvis) includes a broad spectrum of patients with orthopaedic trauma, likely with varying inpatient resource utilization. With the growing incidence of fractures in the elderly, inadequate reimbursements from Medicare for certain patients with DRG 536 may lead to growing financial strain on healthcare institutions caring for these patients with higher costs. QUESTIONS/PURPOSES: The purposes of the study were to determine whether (1) inpatient length of stay; (2) intensive care unit stay; and (3) ventilator time differ among subpopulations with Medicare DRG 536. METHODS: A total of 56,683 patients, 65 years or older, with fractures of the hip or pelvis were identified in the 2011 and 2012 National Trauma Data Bank. This clinical registry contains data on trauma cases from more than 900 participating trauma centers, allowing analysis of resource utilization in centers across the United States. Patients were grouped in the following subgroups: hip fractures (n = 35,119), nonoperative pelvic fractures (n = 15,506), acetabulum fractures, operative and nonoperative, (n = 7670), and operative pelvic fractures (n = 682). Total inpatient length of stay, intensive care unit (ICU) stay, and ventilator time were compared across groups using multivariate analysis that controlled for hospital factors. RESULTS: After controlling for patient and hospital factors, difference in inpatient length of stay was -0.2 days for patients with nonoperative pelvis fractures compared with inpatient length of stay for patients with hip fractures (95% CI, -0.4 to -0.1 days; p = 0.001); 1.7 days for patient with acetabulum fractures (95% CI, 1.4-1.9 days; p < 0.001); and 7.7 days for patients with operative pelvic fractures (95% CI, 7.0-8.4 days; p < 0.001). The difference in ICU length of stay for patients with nonoperative pelvis fractures was 0.8 days compared with ICU length of stay for patients with hip fractures (95% CI, 0.7-0.9 days; p < 0.001); 1.9 days for patients with acetabulum fractures (95% CI, 1.8-2.1 days; p < 0.001); and 6.3 days for patients with operative pelvic fractures (95% CI, 5.9-6.7 days; p < 0.001). The difference in mechanical ventilation time for patients with nonoperative fractures was 0.5 days compared with ventilation time for patients with hip fractures (95% CI, 0.4-0.6 days; p < 0.001); 1.1 days for patients with acetabulum fractures (95% CI, 1.0-1.2 days; p < 0.001); and 3.9 days for patients with operative fractures (95% CI, 2.5-3.2 days; p < 0.001). CONCLUSIONS: In our current multitiered trauma system, certain centers will see higher proportions of patients with acetabulum and operative pelvic fractures. Because hospitals are reimbursed equally for these subgroups of Medicare DRG 536, centers that care for a greater proportion of patients with more-complex pelvic trauma will experience lower financial margins per trauma patient, limiting their potential for growth and investment compared with competing institutions that may not routinely see patients with high-energy trauma. Because of this, we believe reevaluation of this Medicare Prospective Payment System DRG is warranted. LEVEL OF EVIDENCE: Level IV, economic and decision analysis.

Using Hounsfield Units to Assess Osteoporotic Status on Wrist Computed Tomography Scans: Comparison With Dual Energy X-Ray Absorptiometry.

PURPOSE: Rates of evaluation and treatment for osteoporosis following distal radius fragility fractures remain low. As a subset of patients with these fractures undergo diagnostic computed tomography (CT) scan of the wrist, utilizing bone mineral density (BMD) measurements available with this imaging can be used to detect osteopenia or osteoporosis. This information may consequently prompt intervention to prevent a subsequent fracture. The purpose of this study was to determine if Hounsfield unit (HU) measurements at the wrist correlate with BMD measurements of the hip, femoral neck, and lumbar spine and to assess the ability of these HU measurements to detect osteoporosis of the hip. METHODS: Forty-five female patients with distal radius fractures who underwent CT scan and dual energy x-ray absorptiometry scan as part of the management of their wrist fracture were identified. Bone mineral density measurements were made using the regional cancellous bone HU value at the capitate and compared with values obtained by a dual energy x-ray absorptiometry scan. RESULTS: Hounsfield unit values at the capitate were significantly correlated with BMD and t scores at the femoral neck, hip, and lumbar spine. An HU threshold of 307 in the capitate optimized sensitivity (86%) and specificity (94%) for detecting osteoporotic patients. CONCLUSIONS: By demonstrating that capitate HU measurements from clinical CT scans are correlated with BMD and t scores at the hip, femoral neck, and lumbar spine, our data suggest that clinical CT scans should have a role in detecting osteopenia and osteoporosis. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

Comparison of Sagittal Balance between Radiofrequency Targeted Vertebral Augmentation and Balloon Kyphoplasty in Treatment of Vertebral Compression Fracture: A Retrospective Study.

Objective: To compare the effectiveness of high viscosity cement radiofrequency targeted vertebral augmentation (RF-TVA) and balloon kyphoplasty on spinal sagittal balance through radiologic evaluation. Material and Method: The present retrospective study included patients whom underwent either balloon kyphoplasty utilizing the Kyphon system or RF-TVA utilizing the DFine system between 2007 and 2014. Medical record reviews included demographic data and radiographic findings including pre- and post-operative lateral radiographs of the whole spine and post-operative computerized topography. All spinal sagittal alignment parameters such as pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), sagittal vertical axis (SVA), and spinosacral angle (SSA) were measured and evaluated. Results: Thirty-three vertebral compression fracture (VCF) patients were included in the present study. Sixteen of them underwent RF-TVA and 17 underwent balloon kyphoplasty. There were no significant differences in age, gender, and pre-operative spinal sagittal alignment parameters between these two groups of patients. In the RF-TVA group, there were no significant differences in percent of vertebral collapse and kyphotic angle between pre-and post-operative radiographs. In the balloon kyphoplasty group, there were significant improvement in both percent of vertebral collapse and kyphotic angle. The balloon kyphoplasty group also showed a statistically significant change in pelvic tilt (p = 0.02). Neither group demonstrated statistically significant changes in any other spinal sagittal alignment parameters (p>0.05). Conclusion: The RF-TVA and balloon kyphoplasty did not play a role in improving the whole spine alignment in the treatment of VCF. However, balloon kyphoplasty did demonstrate regional improvement of the VCF.

A comprehensive overview of osteoporotic fracture treatment.

Osteoporosis is a worldwide epidemic, affecting more than 75 million people in the United States, Europe, and Japan. At a consensus conference in 1990, European and American leaders defined osteoporosis as a disease characterized by low bone mass, microarchitectural deterioration of bone tissue, and a resulting increase in fracture risk. In 2000, the National Institutes of Health modified this definition, describing osteoporosis as a skeletal disorder characterized by compromised bone strength and a predisposition for increased fracture risk. It was emphasized that bone strength, which is a more comprehensive concept than bone mass, integrates the concepts of both bone density and bone quality. As orthopaedic surgeons, recognizing osteoporosis and its healthcare implications is critical to optimize the musculoskeletal health of patients of all ages and both sexes.

Risedronate in children with osteogenesis imperfecta: a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Children with osteogenesis imperfecta are often treated with intravenous bisphosphonates. We aimed to assess the safety and efficacy of risedronate, an orally administered third-generation bisphosphonate, in children with the disease. METHODS: In this multicentre, randomised, parallel, double-blind, placebo-controlled trial, children aged 4-15 years with osteogenesis imperfecta and increased fracture risk were randomly assigned by telephone randomisation system in a 2:1 ratio to receive either daily risedronate (2·5 or 5 mg) or placebo for 1 year. Study treatment was masked from patients, investigators, and study centre personnel. Thereafter, all children received risedronate for 2 additional years in an open-label extension. The primary efficacy endpoint was percentage change in lumbar spine areal bone mineral density (BMD) at 1 year. The primary efficacy analysis was done by ANCOVA, with treatment, age group, and pooled centre as fixed effects, and baseline as covariate. Analyses were based on the intention-to-treat population, which included all patients who were randomly assigned and took at least one dose of assigned study treatment. The trial is registered with ClinicalTrials.gov, number NCT00106028. FINDINGS: Of 147 patients, 97 were randomly assigned to the risedronate group and 50 to the placebo group. Three patients from the risedronate group and one from the placebo group did not receive study treatment, leaving 94 and 49 in the intention-to-treat population, respectively. The mean increase in lumbar spine areal BMD after 1 year was 16·3% in the risedronate group and 7·6% in the placebo group (difference 8·7%, 95% CI 5·7-11·7; p<0·0001). After 1 year, clinical fractures had occurred in 29 (31%) of 94 patients in the risedronate group and 24 (49%) of 49 patients in the placebo group (p=0·0446). During years 2 and 3 (open-label phase), clinical fractures were reported in 46 (53%) of 87 patients in the group that had received risedronate since the start of the study, and 32 (65%) of 49 patients in the group that had been given placebo during the first year. Adverse event profiles were otherwise similar between the two groups, including frequencies of reported upper-gastrointestinal and selected musculoskeletal adverse events. INTERPRETATION: Oral risedronate increased areal BMD and reduced the risk of first and recurrent clinical fractures in children with osteogenesis imperfecta, and the drug was generally well tolerated. Risedronate should be regarded as a treatment option for children with osteogenesis imperfecta. FUNDING: Alliance for Better Bone Health (Warner Chilcott and Sanofi).

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.

Heat and radiofrequency plasma glow discharge pretreatment of a titanium alloy promote bone formation and osseointegration.

Orthopedic and dental implants manifest increased failure rates when inserted into low density bone. We determined whether chemical pretreatments of a titanium alloy implant material stimulated new bone formation to increase osseointegration in vivo in trabecular bone using a rat model. Titanium alloy rods were untreated or pretreated with heat (600°C) or radiofrequency plasma glow discharge (RFGD). The rods were then coated with the extracellular matrix protein fibronectin (1 nM) or left uncoated and surgically implanted into the rat femoral medullary cavity. Animals were euthanized 3 or 6 weeks later, and femurs were removed for analysis. The number of trabeculae in contact with the implant surface, surface contact between trabeculae and the implant, and the length and area of bone attached to the implant were measured by histomorphometry. Implant shear strength was measured by a pull-out test. Both pretreatments and fibronectin enhanced the number of trabeculae bonding with the implant and trabeculae-to-implant surface contact, with greater effects of fibronectin observed with pretreated compared to untreated implants. RFGD pretreatment modestly increased implant shear strength, which was highly correlated (r(2) = 0.87-0.99) with measures of trabecular bonding for untreated and RFGD-pretreated implants. In contrast, heat pretreatment increased shear strength 3-5-fold for both uncoated and fibronectin-coated implants at 3 and 6 weeks, suggesting a more rapid increase in implant-femur bonding compared to the other groups. In summary, our findings suggest that the heat and RFGD pretreatments can promote the osseointegration of a titanium alloy implant material.

Atypical femoral fractures: a review of the literature.

Bisphosphonates are the most commonly used drugs worldwide for treating osteoporosis. Atypical femoral fractures most commonly are associated with prolonged bisphosphonate use. They also may occur with denosumab use or in patients without a history of using these drugs. In this article, we provide a comprehensive review of the mechanism of action of bisphosphonate and the definition, incidence, epidemiology, pathogenesis, diagnosis, management, and prevention of atypical femoral fractures.