Potential Fracture Risk Research Articles

Left Coronary Artery Occlusion After Percutaneous Pulmonary Valve Implantation

Percutaneous pulmonary valve implantation (PPVI) is an attractive option for patients with pulmonary valve insufficiency or stenotic right ventricular outflow tracts. We present the case of a 26-year-old patient in which PPVI was used to treat d-transposition of the great arteries, uncommon coronary artery anatomy, and conduit stenosis that resulted from multiple operations on the right outflow. Days after discharge to home, she experienced acute chest discomfort correlating with ischemia noted on an electrocardiogram and elevated troponin levels. Coronary angiography confirmed mechanical compression of the left anterior descending coronary artery. The valve was removed in an emergency operation and replaced with a biological conduit.

Choice of observational study design impacts on measurement of antipsychotic risks in the elderly: a systematic review

BackgroundAntipsychotics are frequently and increasingly prescribed to treat the behavioural symptoms associated with dementia despite their modest efficacy. Evidence regarding the potential adverse events of antipsychotics is limited and little is known about the longer-term safety of these medicines in the elderly. The aim of this review was to determine the impact of the choice of observational study design and methods used to control for confounding on the measurement of antipsychotic risks in elderly patients.MethodsWe searched PUBMED and the Cochrane controlled trials register for double-blind randomised controlled trials (RCTs), meta-analyses and published observational studies of antipsychotics.ResultsForty four studies were identified for the endpoints; death, cerebrovascular events, hip fracture and pneumonia. RCTs found a 20% to 30% increased risk of death, or an absolute increase of 1extra death per 100 patients with atypical antipsychotics compared to non-use. Cohort and instrumental variable analyses estimated between 2 to 7 extra deaths per 100 patients with conventional compared to atypical antipsychotics. RCTs found a 2 to 3 times increased risk of all cerebrovascular events with atypical antipsychotics compared to placebo and no association with serious stroke that required hospitalisation. Observational studies using cohort and self-controlled case-series designs reported similar results; no association where the endpoint was stroke causing hospitalisation and a doubling of risk when minor stroke was included. No RCTs were available for the outcome of hip fracture or pneumonia. Observational studies reported a 20% to 40% increased risk of hip fracture with both antipsychotic classes compared to non-use. The risk of pneumonia was a 2 to 3 times greater with both classes compared to non-use while a self-controlled case-series study estimated a 60% increased risk. Conventional antipsychotics were associated with a 50% greater hip fracture risk than atypical antipsychotics, while the risk of pneumonia was similar between the classes.ConclusionsChoice of observational study design is critical in studying the adverse effects of antispychotics. Cohort and instrumental variable analyses gave more consistent results to clinical studies for mortality outcomes as have self-controlled case-series for the risk of cerebrovascular events and stroke. Observational evidence has highlighted the potential for antipsychotics to be associated with serious adverse events that were not reported in RCTs including hip fracture and pneumonia. Good quality observational studies are required, that employ appropriate study designs that are robust towards unmeasured confounding, to confirm the potential excess risk of hip fracture and pneumonia with antipsychotics.

Age, eGFR, and CKD Complications

Age, eGFR, and CKD Complications

Proton pump inhibitors therapy and risk of hip fracture

Previous studies have reported inconsistent findings that proton pump inhibitors (PPIs) therapy might increase the risk of hip fracture. We investigated the association between PPIs therapy and hip fracture by a systematic review and meta-analysis. We systematically searched PubMed, EMBASE, and the Cochrane Library. We included studies assessing the effects of PPIs on hip fracture. Data from the studies about odds ratio and 95% confidence interval were gathered and summarized. Seven studies met the inclusion criteria. PPIs therapy was associated with a statistically significant increase of hip fracture risk (pooled odds ratio=1.24; 95% confidence interval: 1.15-1.34; P<0.00001) under a random model. Meanwhile, we found that the effect of PPIs on hip fracture differs in different duration groups. These results indicate that PPIs therapy might have the potential risk of hip fracture. Different effects on hip fracture in the subgroup analysis do not support a causal relationship between PPIs and hip fracture. Whether the risk exists warrants further investigation.

Use of Acid-Suppressive Drugs and Risk of Fracture: A Meta-analysis of Observational Studies

Previous studies have reported inconsistent findings regarding the association between the use of acid-suppressive drugs such as proton pump inhibitors (PPIs) and histamine 2 receptor antagonists (H(2)RAs) and fracture risk. We investigated this association using meta-analysis. We searched MEDLINE (PubMed), EMBASE, and the Cochrane Library from inception through December 2010 using common key words. We included case-control, nested case-control, and cohort studies. Two evaluators independently reviewed and selected articles. We determined pooled effect estimates by using random-effects meta-analysis, because of heterogeneity. Of 1,809 articles meeting our initial inclusion criteria, 5 case-control studies, 3 nested case-control studies, and 3 cohort studies were included in the final analyses. The pooled odds ratio (OR) for fracture was 1.29 (95% confidence interval [CI], 1.18-1.41) with use of PPIs and 1.10 (95% CI, 0.99-1.23) with use of H(2)RAs when compared with nonuse of the respective medications. Long-term use of PPIs increased the risk of any fracture (adjusted OR = 1.30; 95% CI, 1.15-1.48) and hip fracture risk (adjusted OR = 1.34; 95% CI, 1.09-1.66), whereas long-term H(2)RA use was not significantly associated with fracture risk. We found possible evidence linking PPI use to an increased risk of fracture, but no association between H(2)RA use and fracture risk. Widespread use of PPIs with the potential risk of fracture is of great importance to public health. Clinicians should carefully consider their decision to prescribe PPIs for patients already having an elevated risk of fracture because of age or other factors.

Retention Strength of Cobalt-Chromium vs Nickel-Chromium Titanium vs CP Titanium in a Cast Framework Association of Removable Partial Overdenture

There is little information considering the framework association between cast clasps and attachments. The aim of this study was to evaluate the retention strength of frameworks match circumferential clasps and extra resilient attachment cast in three different alloys (cobalt-chromium, nickel-chromium titanium and commercially pure titanium), using two undercut (0.25 and 0.75 mm) and considering different period of time (0, 1/2, 1, 2, 3, 4 and 5 years). Using two metallic matrices, representing a partially edentulous mandibular right hemiarch with the first molar crown, canine root and without premolars, 60 frameworks were fabricated. Three groups (n = 20) of each metal were cast and each group was divided into two subgroups (n = 10), corresponding the molar undercut of 0.25 mm and 0.75 mm. The nylon male was positioned at the matrix and attached to the acrylic resin of the prosthetic base. The samples were subjected to an insertion and removal test under artificial saliva environment. The data were analyzed and compared with ANOVAs and Tukey's test at 95% of probability. The groups cast in cobaltchromium and nickel-chromium-titanium had the highest mean retention strength (5.58 N and 6.36 N respectively) without significant difference between them, but statistically different from the group cast in commercially pure titanium, which had the lowest mean retention strength in all the periods (3.46 N). The association frameworks using nickel-chromium- titanium and cobalt-chromium could be used with 0.25 mm and 0.75 mm of undercut, but the titanium samples seems to decrease the retention strength, mainly in the 0.75 mm undercut. The circumferential clasps cast in commercially pure titanium used in 0.75 mm undercuts have a potential risk of fractures, especially after the 2nd year of use. This in vitro study showed that the framework association between cast clasp and an extra resilient attachment are suitable to the three metals evaluated, but strongly suggest extra care with commercially pure titanium in undercut of 0.75 mm. Frameworks fabricated in Cp Ti tend to decrease in retentive strength over time and have a potential risk of fracture in less than 0.75 mm of undercut.

Medial Femoral Condyle Strength After Tunnel Placement for Single- and Double-Bundle Posterior Cruciate Ligament Reconstruction

Single-bundle posterior cruciate ligament (PCL) reconstruction can restore normal posterior laxity; double-bundle reconstruction is needed to more closely mimic normal knee kinematics. Drilling two tunnels removes additional bone from the medial femoral condyle and may interfere with its vascular supply, increasing the risk of fracture or subchondral collapse. Three groups of seven synthetic femurs were tested: no tunnels, single anterolateral 10-mm tunnel, and double tunnel (anterolateral 10-mm tunnel and posteromedial 8-mm tunnel). The distal femur was potted to rigidly hold each specimen during testing. Compressive loading was performed at 2 mm/minute using an Instron (Instron Corp, Canton, Mass). Load and displacement at failure were recorded; stiffness was calculated from those measurements. Mean failure load of the double-tunnel group (7705 N) was significantly lower than the intact group (10962 N, P < .008). No other significant differences were detected. In this model, the double-bundle technique significantly reduced failure force, increasing the potential risk of medial femoral condyle fracture compared to the intact femur. The double-bundle technique also trended toward reduced stiffness. Therefore, a period of postoperative protected weight bearing is recommended.

Underestimation of Bone Loss of the Spine With Posterior-Anterior Dual-Energy X-Ray Absorptiometry in Patients With Spinal Cord Injury

Background: Bone mineral density (BMD) of the lumbar spine (L-spine) has been reported to be normal by routine posterior-anterior (PA) bone density imaging in patients with chronic spinal cord injury (SCI).Objective: To determine BMD of the L-spine by PA and lateral (LAT) dual-energy radiographic absorptiometry (DXA) in patients with chronic SCI.Design: Prospective study.Setting: Veterans Affairs Medical Center and a private rehabilitation facility.Methods: Measurements of the PA and LAT L-spine and hip were performed in 15 patients with SCI: 9 with tetraplegia and 6 with paraplegia. The DXA (GE Lunar Advance DXA) images were obtained using standard software. Results are reported as mean ± SD.Results: The mean age was 35 ± 15 years (range = 20–62 years), and the duration of injury was 57 ± 74 months (range = 3–240 months). T-and Z-scores were lower for the LAT L-spine than those for PA L-spine (T-scores L2: -0.7 ± 1.2 vs 0.0 ± 1.4, P< 0.01; L3: -0.9 ± 1.6 vs 0.3 ± 1.3, P< 0.002; L2-L3: -0.8 ± 1.3 vs 0.2 ±1.3, P< 0.001; Z-scores L2: -0.3 ± 1.1 vs 0.2 ± 1.2, P< 0.05; L3: -0.6 ± 1.3 vs 0.5 ± 1.3, P < 0.01; L2-L3: -0.4 ± 1.1 vs 0.4 ± 1.2, P < 0.005). The T-and Z-scores for the total hip (-1.1 ± 1.0 and -1.0 ± 1.0, respectively) and L2-L3 LAT L-spine demonstrated remarkable similarity, whereas the L2-L3 PA L-spine scores were not reduced. Bone mineral density of the LAT L-spine, but not the PA L-spine, was significantly reduced with increasing duration of injury.Conclusions: Individuals with SCI may have bone loss of the L-spine that is evident on LAT DXA that may be misdiagnosed by PA DXA, underestimating the potential risk of fracture.

Letter to the Editor: Bone Graft Harvest Using a New Intramedullary System

To the Editor: We read with interest the December 2008 article by Belthur et al. [1] entitled “Bone Graft Harvest Using a New Intramedullary System.” The authors’ comparison of iliac crest bone graft harvesting to intramedullary collection with the Reamer/Irrigator/Aspirator (RIA) system (Synthes, Inc, West Chester, PA) is an important study comparing these two methods of bone graft harvesting. In discussing the potential risks associated with RIA, the authors caution, “Care should be taken not to over-thin the femoral cortices. The effect of cortical thinning on mechanical strength of the femoral diaphysis is negligible when overreamed by 2 mm.” Although we acknowledge the potential risk of iatrogenic fracture with over-thinning the cortices, we are curious about the 2 mm limit. Upon review of Pratt et al. [2], we found no mention of a 2 mm limit when reaming femurs. In their biomechanical evaluation of reaming on the torsional strength of femurs, Pratt et al. do not specify the size of the endosteal diameter in relationship to the size of the reamer. Rather they comment that a ratio of reamer diameter to bone diameter greater than 0.48 predicted a “significant change in the way in which the bone fails in torsion.” Would the authors please clarify the basis of their suggested 2 mm limit?

Exemestane

Exemestane (Aromasin) is an orally active steroidal irreversible inactivator of the aromatase enzyme indicated as an adjuvant treatment in postmenopausal women with estrogen receptor-positive early-stage breast cancer following 2-3 years of adjuvant treatment with tamoxifen, and for the treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen or other antiestrogen therapy. Exemestane is effective for the treatment of postmenopausal women with early-stage or advanced breast cancer. In early-stage disease, switching to exemestane for 2-3 years after 2-3 years of adjuvant tamoxifen treatment was more effective in prolonging disease-free survival than continuing tamoxifen therapy, although it was not associated with an overall survival benefit, except in those with estrogen receptor-positive or unknown receptor status disease when nodal status, hormone replacement therapy (HRT) and chemotherapy use were adjusted for. Moreover, preliminary data suggest that the efficacy of exemestane is generally no different to that of tamoxifen in the primary adjuvant treatment of early-stage breast cancer, although exemestane may be better in prolonging the time to distant recurrence. In advanced disease, exemestane showed equivalent efficacy to megestrol in patients with disease refractory to tamoxifen and an efficacy not significantly different from that of fulvestrant in those refractory to a nonsteroidal aromatase inhibitor. Available data, some of which are limited, suggest exemestane is also effective in the first-line hormonal treatment of advanced breast cancer in postmenopausal women. Exemestane is generally well tolerated, although the potential bone fracture risk of the drug requires further investigation. Results from directly comparative trials indicating the efficacy, tolerability and bone fracture risk of exemestane relative to third-generation aromatase inhibitors and other agents in both early-stage and advanced disease, as well as the optimal sequence of endocrine therapies, are awaited with interest. In the meantime, switching to exemestane should be considered in postmenopausal women who have received 2-3 years of adjuvant tamoxifen treatment for early-stage breast cancer, and is an emerging treatment option for postmenopausal women with advanced breast cancer refractory to one or more antiestrogen therapies.

A numerical study of failure mechanisms in the cemented resurfaced femur: Effects of interface characteristics and bone remodelling

Failure mechanisms of the resurfaced femoral head include femoral neck fracture in the short-term and stress shielding and implant loosening in the long-term. In this study, finite element simulations of the resurfaced femur considering a debonded implant-cement interface, variable stem-bone interface conditions, and bone remodelling were used to study load transfer within the resurfaced femur and to investigate its relationship with known failure mechanisms. Realistic three-dimensional finite element models of an intact and resurfaced femur were used. Various conditions at the interface between the stem of the prosthesis and the bone were considered. Loading conditions included normal walking and stair climbing. For all stem-bone contact conditions, the tensile stresses in the cement mantle varied between 1 MPa and 5.4 MPa, except near the distal rim of the resurfacing component where they reached 5.4-7MPa. In the case of full stem-bone contact, high von Mises stresses (114-121MPa) were generated in the implant at the stem-cup junction. These stresses were considerably reduced (maximum von Mises stress, 76 MPa) where a gap was present at the stem-bone interface. Resurfacing led to strain shielding of the bone of the femoral head (20-75 per cent strain reductions) and periprosthetic bone resorption (50-80 per cent bone density reductions) for all interface stem-bone contact conditions. In the lateral femoral head and the proximal femoral shaft around the trochantric region, bone density reductions varied between 10 per cent and 50 per cent. Bone apposition was observed in the inferior-medial part of the femoral head and proximal femoral neck region. For full stem-bone contact, more load was transferred through the stem to the surrounding bone, exacerbating strain shielding. Although femoral hip resurfacing conserves bone stock at the primary operation, strain shielding and periprosthetic bone resorption might lead to eventual loosening over time. Post-operatively, the resurfacing procedure generated elevated strains (0.50-0.75 per cent strain) in the proximal femoral neck-component junction irrespective of the variation in interface conditions, indicating an initial risk of femoral neck fracture. Subsequent to bone remodelling, this strain concentration was considerably reduced (0.35-0.50 per cent strain), lowering the risk of neck fracture. In order to reduce the potential risk of neck fracture, patients should avoid activities which might induce high loading of the hip during the early post-operative period to allow the bone around the proximal femoral neck to remodel and heal.

Incidence and risk factors for low trauma fractures in men with prostate cancer

BackgroundMen with prostate cancer on androgen deprivation therapy (ADT) are at increased risk of bone loss. The present study sought to determine the incidence of low trauma fracture in men with prostate cancer (PC), and to characterize the association between potential risk factors and fracture risk in these men. MethodsIn the prospective, population-based Dubbo Osteoporosis Epidemiology Study, 43 men aged 60+ years reported a history of prostate cancer; among whom, 22 men received ADT, and 21 men did not. Low-trauma fractures were ascertained between 1989 and 2004. Bone mineral density at the femoral neck (FNBMD), postural instability and lifestyle factors were obtained at baseline. ResultsMen with prostate cancer had significantly higher lumbar spine BMD than those without cancer (p=0.013). During the follow-up period, 15 men with prostate cancer had sustained a fracture, yielding the age-adjusted incidence of fracture among this group was 31.6 per 1000 person-years, which was greater than those without cancer (22.1 per 1000 person-years). The age-adjusted incidence of fracture was more pronounced among those with prostate cancer on ADT (40.2 per 1000 person-years). After adjusting for age, the increase in fracture risk among prostate cancer patients was associated with lower femoral neck BMD (hazard ratio [HR] per SD=1.8, 95% CI: 1.0–3.4) and increased rate of bone loss (HR 2.3, 1.2–4.6). ConclusionsMen with prostate cancer, particularly those treated with ADT, had an increased fracture risk. Although the average BMD in men with prostate cancer was higher than men without cancer, a low BMD prior to treatment or increased rate of bone loss after initiating ADT treatment was each a significant predictor of fracture in these.

Residual interface tensile strength of ceramic bonded to dentin after cyclic loading and aging

To guard against the potential risk of cusp fracture, esthetic onlay restorations have been advocated for teeth with large restorations. The influence of the adhesive resin cement is believed to play a role in strengthening these restorations. The durability of this tooth/adhesive/ceramic interface is critical to ensure clinical longevity. The purpose of this study was to assess the effects of cyclic loading and environmental aging on the residual interface strength of a ceramic bonded to dentin structure. Eighteen simple trilayer specimens were fabricated, consisting of a 1.5-mm-thick ceramic plate (ProCAD) bonded to a flattened human molar tooth with exposed coronal dentin. The ceramic plates were bonded using resin cement (Nexus 2) and manufacturer-recommended bonding techniques. The specimens were divided into 3 equal groups and were stored in water at 37 degrees C for 10 weeks as a control group (CT), 9 months as an aging group (AG), or placed in water at 37 degrees C while being subjected to 10 million vertical loading cycles between 20 N to 200 N, as a fatigue group (FG). After the specimens were subjected to the experimental conditions, they were sectioned perpendicular to the flat ceramic surface into 1 x 1-mm sticks. The mean residual interface microtensile bond (MTB) strength was determined for each specimen using only those sticks which contained ceramic bonded to dentin. The MTB strength data were analyzed using Weibull analysis methods to determine differences between groups. All subsequent failed specimen surfaces were evaluated under a stereomicroscope at x10 magnification to determine the apparent failure modes. Some specimens were selected from each failure mode category for surface evaluation under a scanning electron microscope (SEM). The characteristic Weibull means for the 3 groups were CT, 19.2, FG, 14.7, and AG, 11.7. The bond strength of group CT was significantly greater than both AG (P=.007) and FG (P=.014). Light microscopic categorization of the failure modes suggests that adhesive failure at the ceramic/cement interface was the most common (65%) for all 3 groups. SEM evaluation of failed surfaces of select specimens from each group could not distinguish any interface appearance differences. For indirect adhesive-retained ceramic restorations, both cyclic masticatory loading and hydrolytic degradation may contribute to a weakening of the interface bond. The ceramic/resin interface may be more susceptible to these changes over the time frame of this investigation than the dentin/resin interface.

Further exploring hip protector use

Objective: To explore hip protector adherence in high‐risk older people. Methods: In‐depth interviews were conducted with 14 older people (and/or their carers) discharged from hospital with hip protectors. Four outpatients were recruited to supplement numbers. Thematic analysis was carried out on the interview data. Results: Hip protector use largely paralleled daily dressing routines, this contributed to periods of disuse and partial adherence. Another factor in abandoning hip protector use was a fatalistic view of an end of life stage, where injury prevention was not actively sought. Committed carers who demonstrated understanding and support were vital in encouraging ongoing use. Conclusion: Daily routines of a lifetime, reluctance to change, and a readiness to endure the potential risk of hip fracture discouraged use of hip protectors. Family and carer support was vital for continuation. These findings can assist with strategies to improve adherence.

Arthroplasty of the shoulder

Although the first shoulder arthroplasty was implanted in 1893 by the French surgeon Jules-Emile Pean,[1][1] the development of the procedure came in the 1950s when Neer[2][2] described the results using a vitallium prosthesis to treat comminuted fractures of the head of the humerus. About 20

Bone remodelling inside a cemented resurfaced femoral head

Although the short-term performance of modern resurfacing hip arthroplasty is impressive, the long-term performance is still unknown. It is hypothesised that bone remodelling and the resulting changes in stress/strain distribution within the resurfaced femur influence the risk of fixation failure. Three-dimensional finite element models and adaptive bone remodelling algorithms have been used to predict long-term changes in bone density following cemented femoral head resurfacing. Applied loading conditions include normal walking and stair climbing. The remodelling simulation was validated by comparing the results of an analysis of a proximal femur implanted with a Charnley femoral component with known clinical data in terms of bone density adaptations. Resurfacing caused a reduction of strain of 20-70% in the bone underlying the implant as compared to the intact femur, immediately post operative. Elevated strains, ranging between 0.50 and 0.80% strain, were generated post-operatively around the proximal femoral neck regions, indicating a potential risk of neck fracture. However, this strain concentration was considerably reduced after bone remodelling. After remodelling, bone resorption of 60-90% was observed in the bone underlying the implant. Reduction in bone density of 5-47% occurred in the lateral femoral head. Bone apposition was observed in the proximal-medial cortex, around the inferior edge of the implant. Hardly any changes in bone density occurred in the distal neck or the femoral diaphysis. Although resurfacing has produced encouraging clinical results, bone remodelling within the femoral head might be a concern for long-term fixation. Regions of strain concentration at the head-neck junction, which may increase the initial risk of femoral neck fracture, are reduced with bone remodelling. In order to reduce this risk of femoral neck fracture, patients should avoid activities which induce high loading of the hip during the early rehabilitation period after surgery.

Clinical relevance of calcaneal bone cysts: a study of 50 cysts in 47 patients.

The clinical relevance and nature of calcaneal cysts is controversial. The risk of pathologic fracture is undefined and diagnostic criteria to differentiate between cysts in patients who can be treated nonoperatively and patients who require surgical intervention are not available. To address these questions, 50 calcaneal bone cysts in 47 patients were evaluated. The majority of cysts (40 of 50) were asymptomatic and were treated nonoperatively. Cysts reaching a critical size, defined as 100% intracalcaneal cross section in the coronary plane and at least 30% in the sagittal plane, are at risk for becoming symptomatic and at risk for fracture. Fracture is a significant complication and occurred in four of 47 patients, three of whom were treated by open reduction internal fixation and bone grafting. In addition, six patients with symptomatic critical size cysts without apparent fracture were treated by curettage and subsequent autogenous bone grafting or calcium-phosphate cement filling, and there were no recurrences. We report one of the largest series of cysts in the calcaneus. The results suggest that calcaneal cysts are clinically relevant because of the potential risk of fracture and that size is a significant factor in terms of the treatment of the cyst.

The Properties of Endocal 10 and Its Potential Impact on the Structural Integrity of the Root

The purpose of this research was to determine if the use of Endocal 10 (previously called Biocalex 6.9) is associated with root fracture and to assess its sealability. Thirty-six freshly extracted, single canal human mandibular incisors were instrumented and randomly divided into two equal groups (n = 15). Canals in group A were obturated with vertically compacted gutta-percha and Sealapex, and those in group B were filled with Endocal 10 placed with a #25 Lentulo spiral per manufacturer's instructions. Two blinded investigators evaluated the teeth for fractures using transillumination and an operating microscope at 12 x magnification. Three of the fifteen samples filled with Endocal 10 had vertically fractured in half, whereas none of the teeth filled with gutta-percha had any evident fracture lines. The remaining teeth were tested for leakage via a fluid filtration model at 1 wk and 30 days postobturation. No leakage was found among any of the samples whether filled with gutta-percha or with Endocal 10 at either time interval. Statistical analyses were completed using Fisher's exact test (p = 0.023), which showed that there was a significant increase in chance of fracture when using Endocal 10 versus gutta-percha. The results indicate that, although Endocal 10 is able to seal the tooth as well as gutta-percha and sealer, there is a significant potential risk of root fracture.

Bone density changes in Paget’s disease 2 years after iv pamidronate: profound, sustained increases in pagetic bone with severity-related loss in forearm nonpagetic cortical bone

Bone mineral density (BMD) was measured at three sites (forearm, spine, and hip) using dual X-ray and single-photon absorptiometry in 68 patients with Paget’s disease before and after treatment with iv pamidronate. Patients were treated according to the severity of their disease; the mild category (Group I, hydroxyproline excretion (Hyp E) <5.0 μmol/L GF) received 120 mg, the moderate category (Group II, Hyp E 5.0–9.99 μmol/GF) 180 mg, and the severe category (Group III, ≥ 10.0 μmol/GF) 240 mg. Group I was followed for 1 year, and both Groups II and III for 2 years. At the lumbar spine in pagetic bone there were no differences between groups in early responses, with a profound increase 6 months after treatment 20.5 ± 2.0% above baseline values to 1.403 ± 0.063 g/cm 2 (mean ± SEM)( P < 0.001). This increase in BMD was sustained to 2 years (1.355 ± 0.078 g/cm 2, P < 0.001) and was 15.0 ± 2.2% above baseline values. The pagetic total hip BMD increased after treatment in all groups, with a mean rise of 10.4 ± 1.4% at 1 year to 1.505 ± 0.083 g/cm 2 ( P < 0.01). At the pagetic femoral neck the response was similar, with a peak significant rise at 1 year of 10.7 ± 1.7% to 1.403 ± 0.097 g/cm 2 ( P < 0.01). In nonpagetic spinal bone there were no differences between the group responses, with a combined mean increase of 4.3 ± 0.7% at 1 year to 0.999 ± 0.027 g/cm 2 ( P < 0.01). In both Groups II and III the increase in BMD was significantly higher than baseline values at 1 and 2 years ( P < 0.01). In the nonpagetic total hip BMD remained unchanged over the 2-year period and likewise, there were no significant changes from baseline at the nonpagetic femoral neck site. In the nonpagetic forearm we found a significant loss in BMD at the ultradistal (mainly trabecular), midregion (80% cortical), and proximal shaft (95% cortical) sites in Group III, persisting to 2 years at the latter two sites. The increase in bone density in pagetic bone, persisting at least 2 years, provides a new modality of assessment of the response of pagetic bone to treatment and suggests a mechanism for the reduction in fracture risk in such bone after effective bisphosphonate treatment. Severity-dependent nonpagetic forearm bone loss, persisting to 2 years at cortical sites, suggests a potential drug-induced fracture risk at the forearm and possibly elsewhere in the absence of appropriate preventive cotreatment.

Geometria do fêmur proximal em ossos de brasileiros

Objetivo: Fornecer dados sobre a morfometria do fêmur proximal adulto para que se estabeleçam parâmetros e correlações entre as diversas medidas dessa porção do osso de brasileiros. Material e Método: Realizamos a avaliação da geometria da extremidade proximal de 183 fêmures secos de adultos brasileiros, de ambos os sexos, sem idade cronológica determinada. A morfometria constou da obtenção das medidas: comprimento do colo do fêmur (CCF); largura do colo do fêmur (LCF); comprimento do eixo femoral (CEF); ângulo colodiafisário (ACD). Foi realizada também a densitometria óssea (DEXA) de 18 fêmures. A análise estatística constou do cálculo da média aritmética (X); desvio-padrão (SD) e mediana (Me), sendo testadas essas variáveis quanto ao lado através dos testes t de Student e Não- Paramétrico de Mann Whitney. Realizamos a correlação e a regressão linear simples entre as variáveis que apresentavam associação com o CEF. Resultado: Correlacionamos as medidas morfométricas com a densidade mineral óssea (DMO) e as densidades entre si. Encontramos os seguintes valores médios para os lados direito e esquerdo: CCF = 24,9 ± 4,5 mm e 24,3 ± 4,2 mm; LCF = 26,7 ± 3,1 mm e 26,3 ± 3,3 mm; CEF = 92,1 ± 6,9 mm e 92,0 ± 7,1 mm; ACD = 111,2° ± 5,9 e 114,2° ± 5,5. A correlação entre CEF x ACD não foi significante. As correlações entre morfometria e DMO foram menos significativas que as correlações das densidades entre si. Conclusão: Podemos acreditar que a associação entre o CEF e as outras medidas pode ter valor preditivo no risco de fratura. Considerando a importância desse fator, procedemos a este estudo para podermos fornecer dados da geometria femoral de ossos de brasileiros, bem como possibilitar aplicação desses dados na prática clínica.