Burkitt's lymphoma in the appendicular skeleton

Of 290 Ugandan children and adolescents with proven Burkitt's lymphoma 11 had lesions in the long bones or the pelvis. These started in the medulla as small osteolytic foci which coalesced and penetrated the cortex causing subperiosteal new bone formation in layers or spicules, and giving rise to large soft-tissue masses. Common sites were the femoral and tibial diaphyses and the metaphyses around the knee. Five were in the epiphyses. Other sites were the pelvis, humerus and ulna. One patient had a lymphomatous synovial effusion of the knee. In the lower limbs the lesions were often bilateral and symmetrical. Five patients had pathological fractures. Radiologically the lesions mimicked Ewing's sarcoma, osteosarcoma, osteomyelitis, acute leukaemia, syphilis and yaws, but clinically they were relatively painless, an important differential diagnostic feature. In the five patients with sustained remissions after chemotherapy the lesions and fractures healed well and the growth plates were undamaged.     

Adamantinoma of the appendicular skeleton in children

Summary The 260 cases of adamantinoma described in the world literature have been reviewed. Case histories of 60 patients up to the age of 16 years mirror those of adults. The mortality rate is 20% in children and adults. Wide excision with bone grafting is the ideal treatment for patients under 16 years.

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Résumé Deux cent soixante cas bien décrits d'adamantinome du squelette des membres ont été revus à partir de la littérature mondiale. Il est assez surprenant de constater une augmentation récente des cas observés chez l'enfant. La revue des observations de 60 malades âgés de seize ans ou moins fournit des informations comparables dans l'ensemble à celles obtenues chez l'adulte. Une large excision péritumorale suivie de fixation par une greffe osseuse constitue le traitement idéal chez le malade pédiatrique. La mortalité chez l'enfant est de l'ordre de 20%, à peu près identique à celle de l'adulte.

     

Giant-cell tumor of the appendicular skeleton

The common objective of all surgical procedures in the treatment of giant-cell tumor of bone is to minimize the incidence of local recurrence. The purpose of this study was to determine what, if any, patient factors, tumor characteristics, or surgical practices correlate with local recurrence. Seventy-five patients treated for a giant-cell tumor of the appendicular skeleton were followed up for at least 2 years. The mean duration of followup was 62 months (range, 24-224 months). The highest proportion of patients had intralesional curettage, high-speed burring, and adjuvant treatment. Ten patients (13%) had a local recurrence. Bivariate analysis revealed that, with the numbers available, none of the patient variables, tumor variables, or surgical approaches correlated with local recurrence. Post hoc power analysis revealed the power of the study to be 33% to detect a clinically significant difference between treatment groups. The data presented here potentially could contribute to a metaanalysis, which would have the statistical power to determine which tumor-related factors and surgical techniques are most important in predicting recurrence in giant-cell tumor of bone.     

Incorporation of sodium fluoride into cortical bone does not impair the mechanical properties of the appendicular skeleton in rats

Summary Clinical studies on the use of sodium fluoride (NaF) in osteoporotic patients have demonstrated increased spinal bone mass without a reduction in vertebral fracture incidence, and a trend towards reduced appendicular bone mass with an increase in peripheral fracture incidence. As previous reports have suggested that NaF becomes incorporated into bone's crystal structure, possibly affecting bone strength, we sought to examine the relationship among bone fluoride content, bone mass, and skeletal fragility. Twenty-one-day-old female Sprague-Dawley rats were treated with four different doses of NaF. The tibiae were subjected to histomorphometric and biochemical analyses, and the femora were tested in torsion for the properties of strength, stiffness, energy storage capacity, and angular deformation. The results showed that over 50% of the skeleton in these rats was turned over in the presence of NaF. The four different doses resulted in a linear increase in bone F concentration and suggested excellent absorption and incorporation of this drug. No changes in histomorphometric indices of bone formation or turnover were found. Despite the large fraction of bone formed during NaF treatment, and the linear increase in bone fluoride content in relation to dose, there were no changes observed in any of the mechanical properties. These results suggest that, even extensive incorporation of fluoride into bone, in the absence of an effect on bone mass or remodeling, does not significantly alter its capacity to withstand mechanical loads.     

The outcome of surgical treatment for recurrent giant cell tumor in the appendicular skeleton

BackgroundThe treatment for recurrent giant cell tumor (GCT) remains controversial. In this study, we evaluated the outcome of surgical intervention for recurrent GCT.MethodTwenty-seven patients (14 males and 13 females) with recurrent GCT were recruited. Their primary GCTs were all treated with intralesional surgery. Among these recurrent GCTs, 9 grade III and 1 grade II tumors were treated with en bloc resection and endoprosthetic replacement, whereas 16 grade II and 1 grade III tumors were treated with intralesional curettage and PMMA bone cement filling.ResultsThe mean interval between initial surgery and first recurrence was 28.8 months (range 7–97 months). About 70 % of first recurrences affected bones around the knee, 44 % in the proximal tibia and 26 % in the distal femur. Of 27 patients, 3 women treated with intralesional procedures suffered second recurrences in the proximal tibia. No second recurrence was found in patients with en bloc resection. Two grade III re-recurrence GCTs were treated with en bloc resection, and 1 grade II was treated with an intralesional procedure. One patient with en bloc resection developed tumor metastasis in both lungs. Compared to patients with intralesional treatment, the functional score was significantly decreased in patients with en bloc resection (p < 0.01).ConclusionThe re-recurrence risk of grade III GCTs can be significantly decreased by wide en bloc resection and endoprosthetic replacement. However, intralesional treatment is a good option for less aggressive (相似文献   

Surgical treatment of central grade 1 chondrosarcoma of the appendicular skeleton

Background

Diagnosis and treatment of low-grade chondrosarcoma remain controversial. We performed a review of a single-center series with the aims of assessing the oncologic outcome of these patients, verifying if intralesional curettage can be adequate treatment, and defining clinical criteria to support the surgeon and the oncologist in decision-making for surgery and subsequent follow-up.

Materials and methods

A retrospective review of 85 patients was performed (61 females and 24 males, age range 20–76 years). The site of the lesion was the femur in 35 cases, humerus in 33, tibia in 15, and fibula in 2. Sixty-four patients were treated by intralesional curettage. Twenty-one patients with aggressive radiological patterns were treated with wide resection.

Results

Mean follow-up was 67 months (range 24–206 months). Two patients developed local recurrence, both after intralesional curettage. The difference in incidence of recurrence was not statistically significant between the two groups. No distant metastases were observed. Postsurgical complications were significantly higher in the resection group.

Conclusions

Low-grade chondrosarcoma of the appendicular skeleton without aggressive radiological patterns can be treated with intralesional surgery with good oncological outcome and very low rate of postsurgical complications. Wide resection, following surgical principles of malignant bone tumors, should be considered only when aggressive biologic behavior is evident on imaging.     

Multiple pathologic fractures of the appendicular skeleton in a patient with Cushing's disease

A 33-year-old woman with asymptomatic osteoporosis sustained a spontaneous middiaphyseal fracture of the femur as the initial sign of Cushing's disease. Subsequently, she incurred a fracture of the ipsilateral hip and both bones of the forearm. All four fractures failed to unite. There were no symptoms of involvement of the axial skeleton. Although axial osteopenia is the most common skeletal finding in hypercortisolism, fractures exclusively limited to the appendicular skeleton should not preclude detailed diagnostic investigations of hypercortisolism.     

A review of methods currently used for assessment of in vivo endothelial function.

An intact vascular endothelium is critical to the maintenance of normal arterial tone and coagulation status. Endothelial injury leading to dysfunction is thought to be a precursor to most if not all vascular disease, and has been implicated as a critical event in atherosclerosis. At present there are several methods available for detection of in vivo endothelial function, and the aim of this study was to critically review these methods. Five distinct methods were identified and studied in detail. These methods are diverse and each assesses a different vascular bed. Importantly there is no uniformity among investigators over choice of method and protocol, making it difficult to compare in vivo enothelial dysfunction between groups. These issues need to be addressed in large scale comparative analyses so that investigators can agree a common approach to endothelial function assessment.     

Response to parathyroidectomy at the axial and appendicular skeleton in renal patients.

AIM AND METHODS: We report increases in axial and appendicular bone density after parathyroidectomy in renal patients. Bone density was recorded pre-operatively and at 6 weeks, 6 months and 1 year post-operatively. We have previously reported that axial bone density increased dramatically at 6 weeks but that there were no early cohort increases at the appendicular skeleton [Stein et al. 1997]. RESULTS: We now report that at six months, bone density had continued to increase at the lumbar spine and femoral neck, with median respective 6 months increases over baseline of 1.3 (p < 0.01) and 0.7 (p < 0.01 ) Z-scores. Bone density then appeared to stabilize at the axial skeleton. At the appendicular skeleton increases were significant at the one year time point with median respective increases at the ultradistal radius and one third radius of 0.46 (p < 0.05) and 0.49 (p < 0.05) Z-scores. The different pattern of responses to parathyroidectomy between the axial and appendicular sites supports the concept that appendicular bone turnover is slower than axial bone turnover. Furthermore, at the appendicular skeleton, bone turnover appears similar between cortical and trabecular bone. CONCLUSION: In renal patients, bone density increases after parathyroidectomy at both the axial and appendicular skeleton. Axial increases are large and occur early. Appendicular increases occur at both cortical and trabecular sites but are slower than the axial changes.     

Age-dependent change in the 3D structure of cortical porosity at the human femoral midshaft

Microstructural change associated with cortical bone remodeling has been extensively explored with 2D techniques. However, relatively little is known regarding the 3D dynamic microstructure of cortical bone. Therefore, we employed micro-CT imaging to investigate 3D remodeling-related change in the structure of cortical bone porosity across the human lifespan. Anterior femoral midshaft specimens (n=51 male, 28 female) spanning 18 to 92 years of age were scanned with 7 mum nominal isotropic resolution. Canal volume fraction (Ca.V/TV), mean diameter (Ca.Dm), mean separation (Ca.Sp), degree of anisotropy (DA), connectivity density (Ca.ConnD), and number (Ca.N) were calculated for subperiosteal cylindrical regions of interest. Ca.N was calculated in 2D (Ca.N(2D)) and 3D (Ca.N(3D)). Regression was used to examine the relation between the structural parameters and age. Additionally, the impact of sex, height, and weight were investigated collectively (MANCOVA) and individually (ANCOVA). For all analyses, Ca.V/TV and Ca.Dm were inverted (Ca.V/TV(-1), Ca.Dm(-1)) to establish normality and linear relations with age. Ca.N values (2D and 3D) were non-linearly (quadratic) related to age, increasing until the 6th decade then decreasing. This relation was only significant for the pooled sexes Ca.N(3D) values (p=0.012). Ca.ConnD was positively related to age (p<0.05), while all remaining 3D parameters, except DA for males (p=0.070), were negatively related (p<0.05). In all cases, the relation with age was strongest for females. MANCOVA revealed that age was the only significant (p<0.001) covariate overall. Univariate ANCOVA indicated significant differences between the sexes for Ca.V/TV(-1) and Ca.Dm(-1) (p=0.018 and 0.010, respectively). Relative to males, females had lower values for these parameters, translating into larger mean canal diameter and overall porosity. Body weight had a significant (p=0.043) positive relation with Ca.Dm(-1), indicating lower weight was also associated with increased mean canal diameter. Therefore, while age was the most important factor, sex and body size were found to play a role in parameters related to canal size and the overall level of porosity. This study is unique in that changes in cortical bone microstructure were examined across the adult human lifespan in three rather than two dimensions.     

Magnesium deficiency: effect on bone mineral density in the mouse appendicular skeleton

Background  

Dietary magnesium (Mg) deficiency in the mouse perturbs bone and mineral homeostasis. The objective of the present study was to evaluate bone mineral density of the femur in control and Mg-deficient mice.     

Quality assessment of the cortical bone of the human mandible

This study is the first to investigate simultaneously both the regional and the directional variations in mechanical properties and computed tomography (CT) numbers of the fresh mandible bone and to explore the correlation between the two sets of data with a view to provide a noninvasive method for determining the bone quality for designers of dental implants. Using a three-point bending test the regional variation of Young's modulus of bone in the human mandible was determined from five fresh specimens from donors representative of patients in need of dental implants in that some of the mandibles were fully dentulate, some partly so, and some fully edentulate. While a pattern of the modulus distribution was evident in the mandibles we tested, these mandibles did have, as a result of their respective states, their own peculiarities. We determined also the directional variations of the modulus for the mandible, which are due to the anisotropic nature of bone. The modulus values obtained in our study were much lower than those listed in the only other published study, which was conducted on dry mandibles. These differences in the modulus data from the two studies were attributed partly to the differences in condition of the bone and differences in the dimensions of specimens tested in the two studies. Because the values of the modulus obtained in this study are lower than those previously published, they would be safer as a basis for implant designs. A weak correlation was found between the modulus values and the CT number of the mandible. This would not be sufficient for accurate predictions of the bone properties from CT scans. The development of a noninvasive method for determining the bone quality in various patients thus remains a challenge for researchers.     

Spongious and cortical osteoblastoma of the axial skeleton

Eleven cases of osteoblastoma (spongious osteoblastoma) and four cases of osteoid osteoma (cortical osteoblastoma) involving the spine, diagnosed at Hadassah Hospital between 1970 and 1983 were analyzed. The age range was 7 to 34 years and the average clinical follow up was 63 months. The cervical spine was involved in four patients, thoracic in four, lumbar in six and the sacrum in one patient. Back or neck pain associated with stiffness was present in all cases and was often accompanied by scoliosis or torticollis. All the patients with osteoid osteoma were symptom relieved by surgery without recurrence. Seven of the patients with benign osteoblastoma presented with neurological signs or symptoms and three of these had recurrence following primary surgery. Although cortical and spongious osteoblastoma are considered as members of the same family of benign tumors of osteoblastic derivation, spongious osteoblastoma does not seem to be limited in growth potential as is cortical osteoblastoma.     

A novel mechanism for induction of increased cortical porosity in cases of intracapsular hip fracture

It has been suggested that, in hip fracture, the cortex on the inferoanterior (IA) to superoposterior (SP) axis is thinned and shows increased porosity. This is dependent on the presence of giant canals (i.e., diameter >385 microm), which are related to clusters of remodeling osteons. To investigate further the relationship between remodeling and bone loss, osteonal diameter (On.Dm), wall thickness (W.Th), osteoid width (O.Wi), and extent (OS) were measured in femoral neck biopsies from 12 female intracapsular hip fracture cases and 11 age- and gender-matched controls. Over 83% of giant canals were "composite" osteonal systems in which a single canal was surrounded by multiple packets of osteonal bone. Among smaller canals, over 80% of systems had a canal encircled by a single cement line containing one packet of bone ("simple"). Composites were nearly twice as prevalent in fractures (fracture cases 9.8 +/- 0.7/25 mm(2), controls 5.3 +/- 0.4/25 mm(2), p < 0. 0001), and were dependent (R(2) = 0.52) on femoral neck region (p = 0.0008) and the regional distribution of clusters of remodeling osteons (p = 0.0045). Both the inferior (I) and anterior (A) regions had an elevated number of composites (I: 263% of control values, p = 0.0054; A: 202% of control values, p = 0.0092). On.Dm was similar in fracture cases and controls (simple: fracture cases 183 +/- 3 microm, controls 191 +/- 4 microm; composites: fracture cases 446 +/- 13 microm, controls 460 +/- 13 microm). W.Th in simples was similar in fracture cases and controls (fracture cases 51 +/- 0.8 microm, controls 49 +/- 0.7 microm), but composites had significantly (p < 0. 0001) thinner walls, with the reduction in fracture cases (31%) being twice that of controls (12%, p < 0.0001). There were no differences in O.Wi. It was unusual for osteoid to fully surround the composite canal surface; OS was 38% lower in composite than simple canals (p < 0.0001). This study indicates that, in the femoral neck cortex, the principal remodeling deficit in hip fracture is specific to composite osteons. Hip fracture cases had zonal increases in composite osteon density with reduced bone formation. The data suggest that generation of composite osteons is a plausible mechanism leading to increasing porosity and trabecularization of the cortex, thus weakening the cortex in regions maximally loaded on fall impact.