Femoral neck stress fractures and metabolic bone disease

OBJECTIVE: To determine whether metabolic bone disease plays a role in the cause of femoral neck stress fractures. STUDY DESIGN: Twenty-three patients with femoral neck stress fractures were enrolled prospectively in the study. Examination included computed tomography bone densitometry, trace mineral analysis, and histomorphometric analysis of the iliac crest in thirteen patients who underwent surgical treatment of their stress fractures. A control group of fifteen patients undergoing iliac crest bone grafting for scaphoid nonunions underwent similar examinations. SETTING: Tertiary military medical center. RESULTS: Patients with femoral neck stress fractures had lower bone mineral density than did control patients (p = 0.010), but no trace mineral deficiencies or consistent histomorphometric differences were noted. CONCLUSIONS: Bone mineral density is decreased in patients with femoral neck stress fractures. Despite observations of decreased bone mineral density in the stress fracture group, osteoporosis, as determined by histomorphometry, is not a consistent finding.     

医用磷酸钙在特发性脊柱侧凸矫形融合术中的应用

[目的]比较医用磷酸钙和自体髂骨在特发性脊柱侧凸矫形融合术中的临床效果.[方法]回顾性分析2006年6月～2009年1月在本科行钉-棒内固定系统矫形手术的62例特发性脊柱侧凸患者,其中自体髂骨移植组28例,医用磷酸钙移植组34例.对两组患者的平均手术时间、出血量、并发症、融合率、矫形丢失进行对比分析.[结果]62例患者均获得随访,每组至少随访24个月.两组患者出血量、手术时间相比,差异有统计学意义(P＜0.05).在自体髂骨组中,有2例(7.1％)出现感染,1例(3.6％)出现躯干不平衡,3例(10.7％)患者在最后一次随访中供区疼痛仍未消失.在磷酸钙组中,有2例(5.8％)出现术后切口渗出,1例(2.9％)出现感染.在移植术后第9个月,自体髂骨组融合率高于磷酸钙组(P＜0.05),其他时间相比两组融合率无统计学意义(P＞0.05).在术后最终随访中,主弯Cobb角度矫形丢失两组差异无统计学意义(P＞0.05).[结论]医用磷酸钙应用于特发性脊柱侧凸患者的后路融合术中可以达到满意的临床效果,避免了取髂骨移植带来的相应并发症.     

Persistent osteopenia in adolescent idiopathic scoliosis. A longitudinal follow up study.

STUDY DESIGN: A follow-up study assessing the bone mineral dynamics in adolescent patients with idiopathic scoliosis and associated osteopenia. OBJECTIVES: To investigate whether osteopenia in patients with adolescent idiopathic scoliosis is a transient phenomenon or a persistent problem. SUMMARY OF BACKGROUND DATA: Investigators have suggested a significant correlation of osteopenia with adolescent idiopathic scoliosis. Because one half of the skeletal mass is acquired during the adolescent years, it is of importance to know whether the osteopenia is transient or persistent. METHODS: Using dual-energy x-ray absorptiometry, bone mineral density of bilateral proximal femurs was studied longitudinally in 70 healthy control subjects and 14 patients with adolescent idiopathic scoliosis with significant osteopenia more than 2 standard deviations below the mean normal value. RESULTS: The 14 girls with osteopenic adolescent idiopathic scoliosis who were followed up longitudinally for up to 3 years showed persistent and significantly lower bone mineral density when compared with normal age-, sex- and maturity-matched control subjects. CONCLUSIONS: Patients with adolescent idiopathic scoliosis are at increased risk of osteoporosis than are healthy adolescents. The lower rate of increase of bone mineral density in patients with adolescent idiopathic scoliosis who have low bone mineral density could predict a significantly lower peak bone mass in adulthood, with all the associated problems of osteoporosis. Further investigation is needed to define whether osteopenia-associated scoliosis has the same cause, pathogenetic mechanism, and risk of progression when compared with adolescent scoliosis without osteopenia.     

Morbidity of iliac crest bone graft harvesting in adolescent deformity surgery

The iliac crest as a source of bone graft has remained popular and continues to be the standard source of bone graft material in spinal arthrodesis surgery. The purpose of the present study was to quantify the frequency and severity of posterior iliac crest bone graft harvest site pain associated with adolescent spinal deformity correction procedures. Patients were evaluated prospectively at a minimum of 1 year after a spinal fusion procedure for idiopathic scoliosis or kyphosis. Patients were asked to quantify the pain level at their harvest site over the previous month based on a 0-to-10 numeric rating scale. Data were collected on 71 patients: 60 with adolescent idiopathic scoliosis and 11 with Scheuermann's kyphosis. There was no gender difference noted, with 1 of the 10 boys (10%) and 6 of the 61 girls (10%) reporting postoperative pain. Seven of 60 patients with scoliosis reported pain (12%), whereas none of the patients with Scheuermann's kyphosis reported pain. None reported a pain level greater than 3 of 10 or any effect on activity level. This series shows that iliac crest bone graft harvest site pain is absent in most patients (90%) and of limited severity in those who reported pain (score 相似文献   

Trabecular bone micro‐architecture and bone mineral density in adolescent idiopathic and congenital scoliosis

Objective: To investigate the microstructure of trabecular bone in adolescent idiopathic scoliosis (AIS) and age‐matched congenital scoliosis (CS), and to evaluate the bone mineral status of CS patients compared with normal controls and AIS patients. Methods: This study included 15 AIS and 16 CS female patients and 35 healthy female adolescents. Corrective surgery was indicated for the AIS and CS patients, from whom iliac crest biopsies were collected during autograft harvesting, and scanned by micro‐computer tomography. Bone mineral status was assessed at the lumbar and hip areas in every patient by dual energy X‐ray absorptiometry (DEXA). Results: Significantly lower lumbar and femoral neck bone mineral density (BMD) was found in AIS patient compared with normal controls. All BMD and bone mineral content (BMC) parameters were significantly lower in CS patients compared with age‐matched normal controls. Under DEXA assessment significant associations between bone volume/tissue volume (BV/TV) and BMD values were observed. In the 3D model, BV/TV was significantly higher in AIS (19.9% ± 3.4%) than in CS (13.3% ± 3.0%, P < 0.05). Significant differences between AIS and CS were also found in trabecular thickness (Tb.Th) and bone surface/bone volume (BS/BV) (155.5 ± 54.9 µm vs. 108.1 ± 17.4 µm and 16.4% ± 3.3% vs. 22.0% ± 3.4% respectively, P < 0.05 in both). Conclusion: Lower bone mineral status and weak trabecular bone structure observed in AIS and CS justify further investigation of the bone mineral status in scoliosis of various etiologies.     

青少年特发性脊柱侧凸患者后路髂棘处取骨植骨并发症

目的探讨青少年特发性脊柱侧凸患者后路髂棘处取骨并发症的发生率。方法对1999～2002年201例后路取髂骨行脊柱植骨融合术的青少年特发性脊柱侧凸患者进行回顾性研究。其中85例患者获得随访，最短随访时间为2年。结果住院期间有2例发生局部感染，通过灌洗引流和清创得到恢复。1例发生髂骨内板穿透，未引起临床症状。3例发生持续性疼痛，1例发生麻木。总的并发症发生率为3。5％。在随访的85例患者中，21例(24。7％)有髂棘取骨处疼痛，其中13例(15．3％)影响日常生活。7例(8．2％)需要服用非甾体类抗炎药以缓解取骨部位疼痛。6例(7.1％)瘢痕周围的皮肤感觉过敏，15例(17．6％)有瘢痕周围皮肤麻木。结论尽管青少年脊柱侧凸患者住院期间髂棘取骨处并发症较低，但经过长期随访，疼痛及麻木的并发症明显增高，应值得更多关注。     

Correlation of Risser sign and bone age determination in adolescent idiopathic scoliosis

At the present, there appears to be a lack of unanimity in the choice of whether the Risser sign (iliac apophysis maturation) or determination of skeletal maturation by bone age roentgenograms is the more accurate indicator of maturity in adolescent idiopathic scoliosis. In an effort to clarify this issue, the authors correlated data from 111 patients to determine the relationship between accuracy of Risser sign and bone age determinations performed during similar chronologic intervals. Data from bone age determinations were then correlated with Risser sign data, and a regression line statistical determination was made. The iliac crest apophysis maturation was statistically significantly (p less than 0.01) correlated with data retrieved by skeletal age assessment.     

Osteopenia: a new prognostic factor of curve progression in adolescent idiopathic scoliosis

BACKGROUND: Studies have shown that 27% to 38% of girls with adolescent idiopathic scoliosis have systemic osteopenia. The aim of this study was to investigate whether osteopenia could serve as one of the important prognostic factors in predicting curve progression. METHODS: A prospective study was performed in 324 adolescent girls with adolescent idiopathic scoliosis who had a mean age of thirteen and a half years. Bone mineral density of the spine and both hips was measured at the time of the clinical diagnosis of scoliosis. All patients were followed longitudinally until skeletal maturity or until the curve had progressed > or =6 degrees . The univariate chi-square test and stepwise logistic regression were used to predict the prevalence of curve progression, and a receiver operating characteristic curve was plotted. RESULTS: The overall prevalence of curve progression was 50%. The prevalence of osteopenia at the spine and hips was 27.5% and 23.1%, respectively. A larger initial Cobb angle (odds ratio = 4.6), a lower Risser grade (odds ratio = 4.7), premenarchal status (odds ratio = 2.5), osteopenia in the femoral neck of the hip on the side of the concavity (odds ratio = 2.3), and a younger age at the time of diagnosis (odds ratio = 2.1) were identified as risk factors in predicting curve progression. A predictive model was established, and the area under the receiver operating characteristic curve of the model was 0.80 (p < 0.01). CONCLUSION: Osteopenia may be an important risk factor in curve progression. The measurement of bone mineral density at the time of diagnosis may serve as an additional objective measurement in predicting curve progression in adolescent idiopathic scoliosis. The bone mineral density-inclusive predictive model may be used in treatment planning for patients with adolescent idiopathic scoliosis who are at high risk of curve progression.     

Pulmonary function in adolescent idiopathic scoliosis relative to the surgical procedure

BACKGROUND: The long-term pulmonary function of patients with adolescent idiopathic scoliosis undergoing surgical correction is uncertain. To our knowledge, no report has demonstrated the changes in pulmonary function five years or more following spinal arthrodesis with use of modern segmental spinal instrumentation techniques for the treatment of all types of adolescent idiopathic scoliosis in a similar adolescent population. METHODS: One hundred and eighteen patients with adolescent idiopathic scoliosis undergoing surgical treatment at a single institution were evaluated with pulmonary function tests to assess the absolute and percent-predicted value of forced vital capacity and forced expiratory volume in one second at the preoperative examination and at regular intervals postoperatively. The patients were divided into four groups depending upon the surgical procedure: Group 1 comprised forty-nine patients who had posterior spinal arthrodesis with iliac crest bone graft; Group 2, forty-one patients who had posterior spinal arthrodesis with thoracoplasty; Group 3, sixteen patients who had open anterior spinal arthrodesis with a rib resection thoracotomy; and Group 4, twelve patients who had combined anterior and posterior spinal arthrodesis with a rib resection thoracotomy and iliac crest bone graft, respectively. RESULTS: A comparison of absolute pulmonary function values from the preoperative and final follow-up evaluations demonstrated a significant (p < 0.0001) increase in both the forced vital capacity and the forced expiratory volume in one second for Group 1, whereas no change was seen in those values for Groups 2, 3, and 4. A comparison of the changes in the percent-predicted pulmonary function values demonstrated significant (p < 0.05) decreases in forced vital capacity and forced expiratory volume in one second for Groups 2, 3, and 4, except for the latter value for Group 4, whereas Group 1 had no change. CONCLUSIONS: Patients who have had any type of chest cage disruption during the surgical treatment of adolescent idiopathic scoliosis demonstrate no change in the absolute value and a significant decline in the percent-predicted value of pulmonary functions at five years following surgery. Chest cage preservation is recommended to maximize both absolute and percent-predicted pulmonary function values after surgical treatment of adolescent idiopathic scoliosis.     

转录因子Runx2在青少年特发性脊柱侧凸患者成骨细胞中的表达及其意义

目的 从成骨细胞(OB)水平探讨转录因子Runx2与青少年特发性脊柱侧凸(AIS)患者骨量降低的关系.方法 2008年3月至12月行后路手术的AIS患者28例为试验组,男性2例,女性26例;年龄12～18岁,平均14.9岁;Cobb角40～94°,平均57.3°.试验组根据骨密度(BMD)情况又分为:A组(骨量正常组)15例,B组(骨量减低组)13例.正常对照组(C组)为住院治疗的非脊柱畸形的8例患者,男性6例,女性2例;年龄12～18岁,平均15.3岁.各组均采用双能X线吸收测量仪(DEXA)测量骨密度(BMD),测量部位包括非优势侧股骨近端及腰椎.所有受试者术中取适量髂前上嵴的松质骨,运用植块法培养OB.培养至P2代后行表型鉴定,用RT-PCR和Western blot法检测各组Runx2 mRNA及蛋白的表达水平并进行统计学分析.结果 Runx2的mRNA及蛋白水平的表达,B组较A组和c组均降低,差异均有统计学意义(P<0.05),A组与C组差异无统计学意义(P>0.05).结论 Runx2在OB水平mRNA及蛋白表达水平的异常可能与MS骨量降低的分子机制相关.     

Allograft versus autograft bone in scoliosis surgery

The results of a study of the use of autograft versus allograft bone in the surgery of idiopathic adolescent scoliosis are presented. Two groups of patients, matched for age, sex, level and angle of curve, received bone grafts, 20 patients having autogenous bone from the iliac crest and the other 20 having donor bone from a bone bank. Both groups had otherwise identical posterior fusions and Harrington instrumentation. There was no difference between the two groups in a blind, radiographic assessment of bone graft mass at six months, nor in maintenance of the curve correction over the same period. No major operative complications nor failures of instrumentation were encountered. There was, however, a marked reduction in operative time and blood loss in the patients receiving donor bone and also a much lower incidence of late symptoms relating to the operative sites. We conclude that, even in the presence of adequate iliac crest, the use of bank bone is superior for grafting in idiopathic scoliosis surgery.     

Bone density accumulation is not affected by brace treatment of idiopathic scoliosis in adolescent girls

Bracing for adolescent scoliosis has been postulated to cause permanent loss of bone mass and to predispose to adult osteoporosis. To determine whether brace use affects the rate of bone accretion with growth, the authors conducted a prospective study of 52 girls with adolescent idiopathic scoliosis. Dual-energy x-ray absorptiometry (DEXA) showed a significant increase in spinal bone mineral density (BMD) over a 1-year period of brace wear. BMD correlated with measures of growth and pubertal status, but not average daily brace wear or severity of scoliosis. The annual rate of bone density accumulation was similar to reported normal values. The annual rate of change of volumetric bone density increased only slightly during the study period, suggesting that most of the change in BMD with time reflects growth in the dimensions of the spine. Brace treatment does not appear to inhibit bone density accumulation in girls with adolescent idiopathic scoliosis.     

Interrelationships between bone microarchitecture and strength in ovariectomized monkeys treated with teriparatide.

Bone microarchitecture measured at the iliac crest at 6 mo was confirmed to be a reasonable surrogate for, and a predictor of, architecture and strength of the femoral neck and lumbar vertebra after 18 mo of teriparatide treatment. However, the data taken together showed the importance of cortical bone volume for vertebra to assess pharmacological effects on bone quality. INTRODUCTION: Improvements in bone architecture with teriparatide treatment are suggested to contribute to fracture risk reduction in osteoporotic patients. Teriparatide significantly improves microarchitecture in the iliac crest of humans by stimulating bone modeling and remodeling processes that differ dramatically from those induced by antiresorptives. The relationship between improvements of bone microarchitecture and improvements of bone strength with teriparatide treatment has not yet been fully studied. MATERIALS AND METHODS: Ovariectomized monkeys were administered vehicle (n = 20); teriparatide 1.0 microg/kg/d (n = 19); or teriparatide 5.0 microg/kg/d (n = 21) for 18 mo. Iliac crest biopsies were obtained at 6 and 15 mo after initiation of treatment. Animals were killed after 18 mo of treatment, and adjacent vertebrae or contralateral proximal femora were processed for biomechanical or histomorphometric analyses. Pearson correlation analyses were performed to assess the relationship between biomechanical and static histomorphometric parameters of lumbar vertebra, femoral neck, and iliac crest biopsies. RESULTS: Static histomorphometric parameters of the 6- and 15-mo biopsies were significantly correlated with the vertebral and femoral neck parameters obtained at 18 mo of teriparatide treatment. Iliac crest biopsy parameters at 6 and 15 mo also correlated with vertebral and femoral neck strength at 18 mo. Static histomorphometry of the lumbar vertebra and femoral neck at 18 mo also significantly correlated with strength at these sites. However, cortical bone volume of the lumbar vertebrae had the strongest correlation with vertebral and femoral neck strength (r = 0.74 and 0.71, respectively). CONCLUSIONS: Teriparatide dose dependently improved cortical and trabecular microarchitecture of vertebra and femoral neck, as well as trabecular microarchitecture of the iliac crest. Bone microarchitecture at all sites was significantly correlated with lumbar vertebra and femoral neck strength. Cortical bone volume of vertebra had the strongest correlation with vertebral and femoral neck strength. Therefore, structural improvement seemed to be part of the mechanism for improved strength observed with teriparatide treatment. Trabecular bone architecture of the iliac crest at 6 mo also correlated with vertebral and femoral neck strength, as did femoral neck (cortical and trabecular) histomorphometry and trabecular histomorphometry of vertebra after 18 mo of treatment. Because clinical assessment of cortical bone volume is not readily possible for vertebra noninvasively, these findings confirm the importance of iliac crest biopsies to monitor skeletal health and show that biopsies are a reasonable surrogate to assess spine and femoral neck structure and function.     

M-CSF在青少年特发性脊柱侧凸患者成骨细胞中的表达及意义

目的从成骨细胞（osteoblast,OB）水平探讨巨噬细胞集落因子（macrophage colony stimulating factor,MCSF）与青少年特发性脊柱侧凸（adolescent idiopathic scoliosis,AIS）患者骨量降低的关系。方法AIS患者27例,其中男25例,女2例;年龄12～18岁,平均14.9岁;Cobb角40°～94°,平均57.3°。将所有AIS患者分为两组：A组14例,为骨量正常患者;B组13例,为骨量减低患者。正常对照组8例（定为C组）,年龄12～18岁,平均15.3岁。3组均采用双能X线吸收测量仪（dual-energy X-ray absorptiometry,DEXA）测量骨密度（bone mineral density,BMD）,测量部位包括非优势侧股骨近端及腰椎。所有受试者术中取适量髂前上嵴的松质骨,运用植块法培养成骨细胞。培养至P3代后行表型鉴定,用RT-PCR检测AIS组和正常对照组中M-CSF mRNA的表达水平。结果B组中M-CSFmRNA的表达量均较A组（P〈0.05）和C组高（P〈0.05）,A组与C组M-CSFmRNA的表达量无显著统计学差异（P〉0.05）。结论M-CSF在OB水平mRNA表达强度的异常可能与AIS骨量降低的分子机制相关。     

Supplementation of autogenous bone graft with coralline hydroxyapatite in posterior spine fusion for idiopathic adolescent scoliosis

Twenty-seven consecutive patients with adolescent idiopathic scoliosis underwent posterior spinal fusion with pediatric Texas Scottish Rite Hospital instrumentation. Coralline hydroxyapatite (Interpore, Irvine, Calif) was mixed with limited autograft from posterior iliac crest (an approximate 70/30 ratio of coralline hydroxyapatite to autograft). Patient evaluation was based on clinical and radiographic findings. On initial radiographic evaluation, a "snowstorm" appearance consistent with the exoskeleton of the coralline hydroxyapatite was observed. After two years, the fusion mass had a "marble-like" appearance with distinct decreased visibility of the disk spaces in the fusion mass. This latter stage of "marbilization correlated with solid fusion clinically. All patients achieved solid fusion at an average follow-up of 27 months. Coralline hydroxyapatite is safe, biocompatible, and effective in augmenting autogenous bone graft in the treatment of idiopathic adolescent scoliosis with posterior spinal fusion. In addition to decreased donor site morbidity, this may be invaluable in cases where there is insufficient autograft available.     

Distribution of collagen cross-links in normal human trabecular bone.

Infrared imaging analysis of normal human iliac crest biopsy specimens shows a characteristic spatial variation in the nonreducible:reducible collagen cross-links at trabecular surfaces, depending on the surfaces' metabolic status. INTRODUCTION: Bone is a composite material consisting of mineral, collagen, non-collagenous proteins, and lipids. Bone collagen, mainly type I, provides the scaffold on which mineral is deposited and imparts specific mechanical properties, determined in part by the amount of collagen present, its orientation and fibril diameter, and the distribution of its cross-links. MATERIALS AND METHODS: In this study, the technique of Fourier transform infrared imaging (FTIRI) was used to determine the ratio of nonreducible:reducible cross-links, in 2- to 4-microm-thick sections from human iliac crest biopsy specimens (N = 14) at trabecular surfaces as a function of surface activity (forming versus resorbing), with an approximately 6.3-mm spatial resolution. The biopsy specimens were obtained from patients devoid of any metabolic bone disease based on histomorphometric and bone densitometric parameters. RESULTS AND CONCLUSIONS: Distributions of collagen cross-links within the first 50 mm at forming trabecular surfaces demonstrated a progressive increase in the nonreducible:reducible collagen cross-link ratio, unlike in the case of resorbing surfaces, in which the collagen cross-links ratio (as defined for the purposes of the present report) was relatively constant.     

Coronal plane imbalance in adolescent idiopathic scoliosis with left lumbar curves exceeding 40 degrees: the role of the lumbosacral hemicurve

STUDY DESIGN: Retrospective radiographic analysis of the potential role the lumbosacral hemicurve has on adolescent idiopathic scoliosis coronal trunk imbalance. OBJECTIVE: To determine if the lumbosacral hemicurve predisposes adolescent idiopathic scoliosis to coronal decompensation preoperatively and postoperatively. SUMMARY OF BACKGROUND DATA: Although coronal decompensation remains a clinical problem in adolescent idiopathic scoliosis, the literature regarding the role of potential intrinsic structural properties of the lumbosacral hemicurve is sparse. METHODS: Fifty patients with adolescent idiopathic scoliosis were used to measure several potential parameters predisposing to coronal decompensation including lumbosacral hemicurve magnitude and flexibility, sacral and iliac obliquity. RESULTS: Overall, 84% (42/50) demonstrated preoperative decompensation. A more rigid lumbosacral hemicurve was significantly related to preoperative coronal decompensation in the combined and the King I groups. Preoperatively, significant correlation with decompensation was observed for sacral and iliac obliquity in the King I group and for iliac obliquity in the combined group. Postoperatively, coronal decompensation remained significantly correlated to sacral obliquity in the combined group and King I groups. Iliac obliquity was significantly related to postoperative decompensation in the combined group. CONCLUSIONS: The lumbosacral hemicurve represents an important structure predisposing to left coronal plane imbalance in adolescent idiopathic scoliosis that includes a large left lumbar curve as a component of the curve pattern. "At-risk" signs for persistent postoperative coronal decompensation include iliac and sacral obliquity noted on the preoperative standing full-length radiographs.     

Three children with lower limb fractures and a mineralization defect: a novel bone fragility disorder?

In this report, we describe three unrelated children with an apparently novel bone fragility disorder that is associated with an idiopathic mineralization defect. Recurrent lower limb fractures started with weight bearing. The patients had none of the phenotypic, radiological, or histomorphometric features classically associated with known bone fragility disorders such as osteogenesis imperfecta (OI), idiopathic juvenile osteoporosis (IJO), or mild autosomal dominant osteopetrosis. Radiologically, there was increased metaphyseal trabeculation, normal to increased cortical thickness, and no evidence of rickets or osteomalacia. Areal and volumetric bone mineral density (BMD) of the lumbar spine did not show any major alteration. Peripheral quantitative computed tomography of the radius showed elevated cortical thickness and total and trabecular volumetric bone mineral density in one patient. Qualitative histology of iliac bone biopsy specimens showed a paucity of the birefringent pattern of normal lamellar bone. Quantitative histomorphometric analysis demonstrated osteomalacia with a prolonged mineralization lag time in the presence of a decreased mineral apposition rate. There was no biochemical evidence of abnormal calcium or phosphate metabolism. Type I collagen mutation analysis was negative. We conclude that this is a bone fragility disorder of moderate severity that tends to cause fractures in the lower extremities and is associated with the accumulation of osteoid due to an intrinsic mineralization defect. The pathogenetic basis for this disorder remains to be elucidated.     

Is lactose malabsorption a risk factor in fractures of the elderly?

The prevalence of lactose malabsorption (LM) was determined by lactose tolerance tests in 18 women with spinal fragility fractures and 28 women with hip fractures and compared with 35 female controls of the same ethnic background. The association of LM with bone density in the spine, bone mineral density in the distal radius and histomorphometric values of iliac crest biopsies was also evaluated. The prevalence of LM did not differ between the fracture groups and the control subjects. Patients with LM did not differ from those with normal lactose tolerance with regard to bone densitometry or histomorphometric findings in iliac crest biopsies. These results suggest that in Finland LM is not a risk factor for osteopenic fractures in the elderly.     

Abnormalities in bone mineral density and bone histology in thalassemia.

This study demonstrated that there was extensive iron staining on trabecular surface and marked reduction in trabecular bone volume without significant alteration in bone formation and bone resorption rates as well as significant reduction in bone mineral density in 18 thalassemic patients. Serum IGF-I was reduced and may modulate the reduction of bone mass. INTRODUCTION: Bone histomorphometric studies in thalassemia to show alterations in bone histology and their relationship to biochemical parameters are very limited. Therefore, this study was systematically conducted to determine the alterations in thalassemia patients. METHODS: Serum biochemical parameters, trans-iliac crest bone biopsy, and determination of bone mineral density of femur and lumbar spine were done in 18 thalassemic patients (10 females and 8 males). RESULTS: Serum osteocalcin, carboxy terminal teleopeptide fragment of type I collagen, and parathyroid hormone levels were within normal limits, but serum 25(OH) vitamin D (19.3 +/- 1.6 ng/ml) and 1,25(OH)2 vitamin D (33.77 +/- 1.51 pg/ml) levels were decreased. Serum insulin-like growth factor I (IGF-I; 145.2 +/- 20 ng/ml) was suppressed, whereas serum ferritin (1366.6 +/- 253.9 ng/ml) was markedly elevated. Reduced bone mineral density was found in all studied areas. Trabecular bone volume was significantly decreased (16.65 +/- 1.12%), whereas bone formation rate, eroded surface, and other bone histomorphometric parameters were within normal limits. The trabecular bone volume varied significantly with bone mineral density of total femur (r = 0.48, p = 0.04). There was an extensive stainable iron surface on the mineral front (9-60%). Significant correlation between serum IGF-I, serum ferritin, stainable iron surface, and bone mineral density, lumbar spine, and total femur were found. Serum IGF-I correlated with trabecular bone volume (r = 0.6, p = 0.03), inversely with both serum ferritin level (r = -0.6, p < 0.01), and inversely with stainable iron surface (r = -0.53, p = 0.02). Multiple regression analysis demonstrated that IGF-I was the only independent variable that determined bone mineral density of lumbar spine and total femur. CONCLUSION: Low bone mineral density and reduced trabecular bone volume with extensive iron deposition are the predominant findings in thalassemic patients. There was no evidence of increased bone resorption or mineralization defect. A reduction in circulatory IGF-I may modulate the reduction of bone mass.