Gender differences in the association of cognitive impairment with the risk of hip fracture in the older population.

OBJECTIVES: To test the hypothesis that differences by gender will be observed in the association of hip fracture risk with stages of cognitive impairment; and to explore the association between Petersen's "mild cognitive impairment" (MCI) and DSM-5 "mild neurocognitive disorder" (MND). STUDY DESIGN: A community sample of 4803 individuals aged 55+ years was assessed in a two-phase case-finding enquiry in Zaragoza, Spain, and was followed up for 16 years. Medical and psychiatric history was collected with standardized instruments, including the Mini-Mental Status Examination (MMSE), Geriatric Mental State (GMS), History and Aetiology Schedule, and a Risk Factors Questionnaire. The statistical analysis included calculations of Hazard Ratios (HR) in multivariate Cox proportional hazards regression models. MAIN OUTCOME MEASURES: Identified cases of hip fracture, validated by blind researchers. RESULTS: In men, hip fracture risk was increased at the "mild" (HR=4.99 (1.39-17.91)) and at the "severe" (HR=9.31 (1.35-64.06)) stages of cognitive impairment, indicated by MMSE performance. In contrast, in women no association could be documented at the "mild stage" (power=89%), and the association disappeared altogether at the "severe stage" in the final multivariate statistical model (power 100%). No association observed between hip fracture and mild cognitive impairment in both men (power=28% for P-MCI) and women (power=44% and 19% for Petersen's MCI and DSM-5 MND, respectively). CONCLUSIONS: Increased hip fracture risk was associated with "mild" stages of cognitive impairment in men, but not in women. To explore the potential association with the construct MCI or MND, studies with greater statistical power would be required.

Gender differences in the incidence of and risk factors for hip fracture: A 16-year longitudinal study in a southern European population.

OBJECTIVES: To analyze independently in men and women the incidence rate of and risk factors for hip fracture in a southern European population. Illiteracy, dementia, clinically significant depression and disability were factors to receive special emphasis. STUDY DESIGN: A community sample of 4803 individuals aged over 55 years was assessed in a two-phase case-finding study in Zaragoza, Spain, and was followed up for 16 years. Medical history and psychiatric history were collected with standardized instruments, including the History and Aetiology Schedule, the Geriatric Mental State (GMS) scale, and a Risk Factors Questionnaire. Operational criteria were used to define covariates, including diagnostic criteria for both dementia and depression. The statistical analysis included calculations of incidence rate, IR; women/men incidence rate ratio (IRR); and Hazard Ratios (HR) in multivariate Cox proportional hazards regression models. MAIN OUTCOME MEASURES: Cases of hip fracture (International Classification of Diseases, WHO) identified in the treating hospitals, validated by blinded researchers. RESULTS: Hip fractures were more frequent among women than men (IRR=3.1). Illiteracy (HR=1.55) and depression (HR=1.44) increased the risk in women, and smoking (HR=2.13) and disability in basic activities of daily living (HR=3.14) increased the risk in men. Dementia was associated with an increased risk in an univariate analysis, but the association disappeared (power=85% in men, 95% in women) when disability was included in the multivariate models. CONCLUSIONS: The IR of hip fractures was three times higher among women. Illiteracy and clinically significant depression among women and active smoking and disability (HR=3.14) among men independently increased the risk, but dementia did not.

Cementless hydroxyapatite coated hip prostheses.

More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

Prevalence of osteoporotic vertebral fracture in Spanish women over age 45.

The aim of this work is to study the prevalence of osteoporotic vertebral fractures in Spanish women over 45 years of age, based on the selection of a nationwide sample. An observational, cross-sectional, multicenter study was conducted during 2006, in all of Spain's regions. The sample analyzed was of 5000 individuals, representative of the female population over age 45 in Spain. A questionnaire was used to determine which factors are most often associated with vertebral fractures. We also assessed whether the Prevalent Vertebral Fracture Index, proposed by Vogt, is useful in indicating a possible osteoporotic vertebral fracture. Five hundred orthopedic surgeons, from various Spanish regions, were trained in different aspects of the study: inclusion and exclusion criteria, management of the risk factor questionnaire, and implementation of the Vogt questionnaire. The number of fracture cases was 1549 (31.79%). 528 Women (34.08%) had a single vertebral fracture, and 1021 (65.92%) had multiple vertebral fractures. The following factors were statistically significantly associated with vertebral fracture: age, late menarche, early menopause, diabetes mellitus, hyperparathyroidism, rheumatoid arthritis, height loss, daily physical activity, corticosteroid therapy, personal history of osteoporotic fracture and previous diagnosis of osteoporosis. The differences in Vogt score according to age and fracture status were statistically significant. The conclusion of the study is that vertebral osteoporotic fracture in the female Spanish population is frequent. The high prevalence in the Spanish population older than 60 years is probably related to malnutrition in the period from 1936 to 1952.

Study of the polycarbonate-urethane/metal contact in different positions during gait cycle.

Nowadays, a growing number of young and more active patients receive hip replacement. More strenuous activities in such patients involve higher friction and wear rates, with friction on the bearing surface being crucial to ensure arthroplasty survival in the long term. Over the last years, the polycarbonate-urethane has offered a feasible alternative to conventional bearings. A finite element model of a healthy hip joint was developed and adjusted to three gait phases (heel strike, mid-stance, and toe-off), serving as a benchmark for the assessment of the results of joint replacement model. Three equivalent models were made with the polycarbonate-urethane Tribofit system implanted, one for each of the three gait phases, after reproducing a virtual surgery over the respective healthy models. Standard body-weight loads were considered: 230% body-weight toe-off, 275% body-weight mid-stance, and 350% body-weight heel strike. Contact pressures were obtained for the different models. When comparing the results corresponding to the healthy model to polycarbonate-urethane joint, contact areas are similar and so contact pressures are within a narrower value range. In conclusion, polycarbonate-urethane characteristics are similar to those of the joint cartilage. So, it is a favorable alternative to traditional bearing surfaces in total hip arthroplasty, especially in young patients.

Clinical outcomes of minimally invasive versus open approach for one-level transforaminal lumbar interbody fusion at the 3- to 4-year follow-up.

PURPOSE: Supporters of minimally invasive approaches for transforaminal lumbar interbody fusion (TLIF) have reported short-term advantages associated with a reduced soft tissue trauma. Nevertheless, mid- and long-term outcomes and specifically those involving physical activities have not been adequately studied. The aim of this study was to compare the clinical outcomes of mini-open versus classic open surgery for one-level TLIF, with an individualized evaluation of the variables used for the clinical assessment. METHODS: A prospective cohort study was conducted of 41 individuals with degenerative disc disease who underwent a one-level TLIF from January 2007 to June 2008. Patients were randomized into two groups depending on the type of surgery performed: classic open (CL-TLIF) group and mini-open approach (MO-TLIF) group. The visual analog scale (VAS), North American Spine Society (NASS) Low Back Pain Outcome instrument, Oswestry Disability Index (ODI) and the Short Form 36 Health Survey (SF-36) were used for clinical assessment in a minimum 3-year follow-up (36-54 months). RESULTS: Patients of the MO-TLIF group presented lower rates of lumbar (p = 0.194) and sciatic pain (p = 0.427) and performed better in daily life activities, especially in those requiring mild efforts: lifting slight weights (p = 0.081), standing (p = 0.097), carrying groceries (p = 0.033), walking (p = 0.069) and dressing (p = 0.074). Nevertheless, the global scores of the clinical questionnaires showed no statistical differences between the CL-TLIF and the MO-TLIF groups. CONCLUSIONS: Despite an improved functional status of MO-TLIF patients in the short term, the clinical outcomes of mini-open TLIF at the 3- to 4-year follow-up showed no clinically relevant differences to those obtained with open TLIF.

Long-term outcomes of a new model of anatomical hydroxyapatite-coated hip prosthesis.

This prospective study was designed to evaluate 196 Anatomique Benoist Giraud (ABG II) total hip arthroplasties which were implanted between September 1999 and December 2000. A minimum 11 years follow up was completed in 183 cases. The bearing surfaces were polyethylene-zirconia in 84 cases, polyethylene-metal in 42 and ceramic-ceramic in 57. Changes in the femoral stem design, in relation to the previous ABG I model, have led to a significant improvement in stress-shielding. Polyethylene wear rate was lower by more than 50% compared with non-crosslinked polyethylene. Excellent and good results were obtained in 90.32% of cases, and implant survival was 98.39% at the end of follow-up.

A mechanical model for predicting the probability of osteoporotic hip fractures based in DXA measurements and finite element simulation.

BACKGROUND: Osteoporotic hip fractures represent major cause of disability, loss of quality of life and even mortality among the elderly population. Decisions on drug therapy are based on the assessment of risk factors for fracture, from BMD measurements. The combination of biomechanical models with clinical studies could better estimate bone strength and supporting the specialists in their decision. METHODS: A model to assess the probability of fracture, based on the Damage and Fracture Mechanics has been developed, evaluating the mechanical magnitudes involved in the fracture process from clinical BMD measurements. The model is intended for simulating the degenerative process in the skeleton, with the consequent lost of bone mass and hence the decrease of its mechanical resistance which enables the fracture due to different traumatisms. Clinical studies were chosen, both in non-treatment conditions and receiving drug therapy, and fitted to specific patients according their actual BMD measures. The predictive model is applied in a FE simulation of the proximal femur. The fracture zone would be determined according loading scenario (sideway fall, impact, accidental loads, etc.), using the mechanical properties of bone obtained from the evolutionary model corresponding to the considered time. RESULTS: BMD evolution in untreated patients and in those under different treatments was analyzed. Evolutionary curves of fracture probability were obtained from the evolution of mechanical damage. The evolutionary curve of the untreated group of patients presented a marked increase of the fracture probability, while the curves of patients under drug treatment showed variable decreased risks, depending on the therapy type. CONCLUSION: The FE model allowed to obtain detailed maps of damage and fracture probability, identifying high-risk local zones at femoral neck and intertrochanteric and subtrochanteric areas, which are the typical locations of osteoporotic hip fractures.The developed model is suitable for being used in individualized cases. The model might better identify at-risk individuals in early stages of osteoporosis and might be helpful for treatment decisions.

Applications of finite element simulation in orthopedic and trauma surgery.

Research in different areas of orthopedic and trauma surgery requires a methodology that allows both a more economic approach and the ability to reproduce different situations in an easy way. Simulation models have been introduced recently in bioengineering and could become an essential tool in the study of any physiological unity, regardless of its complexity. The main problem in modeling with finite elements simulation is to achieve an accurate reproduction of the anatomy and a perfect correlation of the different structures, in any region of the human body. Authors have developed a mixed technique, joining the use of a three-dimensional laser scanner Roland Picza captured together with computed tomography (CT) and 3D CT images, to achieve a perfect reproduction of the anatomy. Finite element (FE) simulation lets us know the biomechanical changes that take place after hip prostheses or osteosynthesis implantation and biological responses of bone to biomechanical changes. The simulation models are able to predict changes in bone stress distribution around the implant, so allowing preventing future pathologies. The development of a FE model of lumbar spine is another interesting application of the simulation. The model allows research on the lumbar spine, not only in physiological conditions but also simulating different load conditions, to assess the impact on biomechanics. Different degrees of disc degeneration can also be simulated to determine the impact on adjacent anatomical elements. Finally, FE models may be useful to test different fixation systems, i.e., pedicular screws, interbody devices or rigid fixations compared with the dynamic ones. We have also developed models of lumbar spine and hip joint to predict the occurrence of osteoporotic fractures, based on densitometric determinations and specific biomechanical models, including approaches from damage and fracture mechanics. FE simulations also allow us to predict the behavior of orthopedic splints applied to the correction of deformities, providing the recovering force-displacement and angle-moment curves that characterize the mechanical behavior of the splint in the overall range of movement.

Delayed union in pediatric forearm fractures.

BACKGROUND: The aim of this study was to assess the predictive factors of delayed union in pediatric forearm fractures. Few previous reports have approached this complication, but contrary to these studies we excluded cases with known pathogenic factors and included in the sample cases treated with conservative methods. METHODS: This is a case-control study of all pediatric shaft forearm fractures presenting delayed union in a minimum follow-up period of 12 months, from 2003 through 2009, in a hospital covering a health area. Exclusion criteria were fracture dislocations, infection, suboptimal osteosynthesis, greenstick, open, pathologic, and associated radial head fractures. Statistical assessment included bivariate and multivariate linear regression analysis. RESULTS: Four hundred and forty-one complete, both-bone forearm fractures were treated during the study period: 14 of them (3.2%) were identified as suffering delayed union; and 63 controls fulfilling inclusion criteria were randomly selected. Bivariate analysis showed significant differences between "union delay" and "control" groups in age, need of surgical treatment, open versus closed reduction, and mean time to hardware removal. However, open reduction of the fracture, more frequent in the "union delay" group, was the only variable that remained associated with time to consolidation in the multivariate analysis. CONCLUSIONS: The strongest predictor of union delay in pediatric forearm fractures is open reduction. Based on our results, we recommend to avoid when possible the open reduction of the fracture in patients undergoing surgery and to use instead closed reduction and internal fixation. LEVEL OF EVIDENCE: A case-control study. Therapeutic level III.

Male osteoporosis: A review.

Osteoporosis in men is a heterogeneous disease that has received little attention. However, one third of worldwide hip fractures occur in the male population. This problem is more prevalent in people over 70 years of age. The etiology can be idiopathic or secondary to hypogonadism, vitamin D deficiency and inadequate calcium intake, hormonal treatments for prostate cancer, use of toxic and every disease or drug use that alters bone metabolism.Risk factors such as a previous history of fragility fracture should be assessed for the diagnosis. However, risk factors in men are very heterogeneous. There are significant differences in the pharmacological treatment of osteoporosis between men and women fundamentally due to the level of evidence in published trials supporting each treatment. New treatments will offer new therapeutic prospects. The goal of this work is a revision of the present status knowledge about male osteoporosis.

Predictive factors for cutting-out in femoral intramedullary nailing.

BACKGROUND: Femoral intramedullary nailing is currently one of the most frequent surgical treatments for extracapsular hip-fracture fixation. Cutting-out of the lag screw is the main complication of this technique, but only few studies have approached the cutting-out focussed on femoral nailing. The aim of this study was to confirm in patients treated with intramedullary nailing not only with regard to previous reports about the association of cutting-out with technical factors, but also with regard to clinical factors not previously studied. METHODS: Case-control study of all patients sustaining a cut-out of the femoral nail was carried out and a control sample was randomly selected among all extracapsular hip-fracture patients during the study period (2005-2008). All clinical and technical variables were collected from medical records. Orthopaedic Trauma Association (AO/OTA) fracture classification, Singh Osteoporosis Index of the contralateral hip and the American Society of Anaesthesiology (ASA) criteria for preoperative clinical status were used. Statistical assessment included bivariant analysis and multivariant logistic regression analysis. RESULTS: A total of 916 hip-fracture cases were treated in the study period: 33 of them (3.6%) were identified as suffering cutting-out, and 315 controls fulfilling inclusion criteria were also recruited. No statistical differences were found in age, sex or other socio-demographic variables between the two groups. Bivariant analysis showed significant differences between groups in technical variables (tip-apex distance, suboptimal placement of lag screw, fracture diastasis, inadequate fixation quality and distal static locking) and in clinical variables (osteoporosis severity, right hip affected, better previous ability for walking and better preoperative ASA status). Multivariant logistic regression analysis showed significant association only for tip-apex distance and inadequate fixation quality. Differences in distal static locking were close to statistical significance. CONCLUSIONS: The strongest predictor of cutting-out in femoral nailing is tip-apex distance. This study suggests that distal static locking and other clinical conditions play an important role in this fixation failure.

Somatic and psychiatric comorbidity in the general elderly population: results from the ZARADEMP Project.

OBJECTIVE: In a representative sample of the elderly population in a southern European city, we tested the hypothesis that there is an association between general somatic and general psychiatric morbidity. METHODS: A stratified random sample of 4803 individuals aged > or =55 years was selected for the baseline study in the ZARADEMP Project. The elderly were assessed with standardized Spanish versions of instruments, including the Geriatric Mental State (GMS)-AGECAT. Psychiatric cases were diagnosed according to GMS-AGECAT criteria, and somatic morbidity was documented with the EURODEM Risk Factors Questionnaire. RESULTS: General comorbidity clustered in 19.9% of the elderly when hypertension was removed from the somatic conditions category, with 33.5% of the sample remaining free from both somatic and psychiatric illnesses. General comorbidity was associated with age, female gender, and limited education, but did not increase systematically with age. The frequency of psychiatric illness was higher among the somatic cases than among noncases, and the frequency of somatic morbidity among the psychiatric cases was higher than among noncases. This association between somatic and psychiatric morbidity remained statistically significant after controlling for age, gender, and education [odds ratio (OR)=1.61; confidence interval (CI)=1.38-1.88]. Most somatic categories were associated with psychiatric illness, but after adjusting for demographic variables and individual somatic illnesses, the association remained statistically significant only for cerebrovascular accidents (CVAs) (OR=1.47; CI=1.09-1.98) and thyroid disease (OR=1.67; CI=1.10-2.54). CONCLUSION: This is the first study to document that there is a positive and statistically significant association between general somatic morbidity and general psychiatric morbidity in the (predominantly) elderly population. CVAs and thyroid disease may have more weight in this association.

Prevalence of “organic brain syndrome” in a Southern European population in two different time periods. The ZARADEMP Project

Background: Comparative studies of dementia in different time periods are quite limited in the international literature, but might be useful to test environmental hypotheses. The aim of this study is to compare the prevalence of “organic brain syndrome”, as a measure of dementia, in the elderly living in the same community in two different time periods and using the same methods. Methods: Representative samples of the elderly in the Zaragoza Study or ZARADEMP0 (n= 1,080), completed the past decade, and now in Wave I of the ZARADEMP Project or ZARADEMP I (n= 4,803) were interviewed. The Geriatric Mental State (GMS) was the main case-finding instrument and the results were analysed using the AGECAT diagnostic package to generate diagnoses. Results: Adjusted, total prevalence of “organic brain syndrome” in individuals aged 65years and older has not varied from the previous decade. It was 8.4% in ZARADEMP I ,and 7.4% in ZARADEMP 0 (prevalence ratio, PR = 0.83; CI 0.65-1.07). Adjusted prevalence among men was lower in ZARADEMP I (3.6%) when compared to ZARADEMP 0(5.5%), although the differences do not reach statistically significance (PR= 0.65; CI 0.41-1.05). However, in support of the working hypothesis, the differences were more marked, and we consider they reach statistically significant proportions in the age group 80-84years.Conclusions: The prevalence of “organic brain syndrome” has not increased from the previous decade. On the contrary, the prevalence tends to be lower in men, and the differences reach statistical significance in the age group 80-84 years. New analysis using diagnostic criteria of dementia in the same sample are required to confirm these findings (AU)

The ZARADEMP Project on the incidence, prevalence and risk factors of dementia (and depression) in the elderly community: I. The context and the objectives

Background and Objectives: The public health dimension of the problem ofdementia and depression in the elderly population is well documented, but epidemiologicaldata are generally considered to be insufficient and, at times, contradictory. This paperidentifies relevant research areas for the ZARADEMP Project, which follows the ZaragozaStudy (or ZARADEMP 0) and is part of both EURODEM and EURODEP Studies.Methods: Review of the literature. Hypotheses emerging in previous studies of thisresearch group.Results: The following relevant objectives to study in relation to dementia (and depression)have been identified: a) potential variations over time in the prevalence rate; b) provisionof reliable estimations of incidence rates, specific for age and gender; c) data aboutthe course and natural history of so called “mild cognitive deficit”; d) association betweenhypothesized risk factors and cases of dementia (and depression) and its most frequentsubtypes; and e) testing of hypotheses related to the overlap between dementia and depressionand, specifically, to what extent depression has an increased risk for DAT. Otherobjectives of the study are also reviewed, in particular the cross-cultural comparison offindings in Zaragoza and in other European cities incorporated in both EURODEM andEURODEP Studies. The importance of maintaining good, contemporary methodologicalstandards is emphasized.Conclusions: A number of relevant research areas in the epidemiology of both dementiaand depression in the elderly have been identified. Case-control studies based on incidentcases of dementia of the Alzheimer’s type (DAT) to adequately assess risk factorsseem particularly timely (AU)

The ZARADEMP Project on the incidence, prevalence and risk factors of dementia (and depression) in the elderly community: II. Methods and first results

Background: There is a pressing need to identify environmental risk factorsof dementia and depression in the elderly.Aims: To describe the methods and first results of the ZARADEMP Project, the firstpsychiatric study to document risk factors in incident cases of dementia (and depression)in a Southern European elderly population.Method: A three-wave (baseline and two follow-up waves) epidemiological study toidentify incident cases of dementia (and depression) was completed in a representativesample population. Valid Spanish versions of case-finding instruments, including theGeriatric Mental State (GMS) were administered by standardized researchers. The incidentcases, diagnosed by a panel of psychiatrists using DSM-IV criteria, will be includedin a case-control study.Results: Response rate was acceptable (63.6% in Wave I, 87’2% in Wave II and 85’8%in Wave III), and 4,803 individuals completed Wave I. Diagnostic agreement was achievedin 91.4% of probable cases presented to the panel, and a total of 146 incident cases ofdementia were identified.Conclusions: We feel confident that modern epidemiological requirements have beenfulfilled and the statistical power in the calculations of risk will be acceptable (AU)