Pregnancy-associated osteoporosis with seven vertebral compression fractures, a case treated with strontium ranelate.

This paper shows a case of pregnancy-associated osteoporosis (PAO) with seven vertebral compression fractures treated with strontium ranelate and supplementation of calcium and cholecalciferol. Clinical evaluation, laboratory and radiological results are analyzed in the case-report to demonstrate that strontium ranelate is a good option to restore quickly the value of bone mineral density in the treatment of a case of PAO.

The little finger ulnar palmar digital artery perforator flap: anatomical basis.

PURPOSE: The aim of this study was to explore the cutaneous vascularization of the hypothenar region and investigate the anatomical basis for perforator propeller flaps for coverage of the flexor aspect of the little finger. METHODS: The area between the pisiform and the base of the little finger was studied in 14 hands of fresh cadavers injected with red latex. An oval flap 1.5 cm large was raised along the axis between these two points. Perforators going into the flap were dissected up to their origin from the ulnar palmar digital artery of the little finger, and their distance from the proximal edge of the A1 pulley was recorded. RESULTS: The mean number of perforator arteries entering the flap was 5.8 (range 4-8). A constant sizeable perforator was identified within 0.7 cm from the proximal margin of the A1 pulley in all 14 specimens. In the majority of cases (64 %), the most distal perforator was located at this level. Dissection of the flap was carried out suprafascially on the most distal perforator and 180° rotation allowed the flap to reach the flexor surface of the fifth finger. The donor site was closed primarily. CONCLUSION: Distal perforators of the ulnar palmar digital artery of the little finger are constantly found. Our anatomical findings support the possibility of raising a propeller perforator flap from the hypothenar region for coverage of the flexor aspect of the little finger. Its clinical application could provide a quick and straightforward single-stage option with a negligible donor-site morbidity for reconstruction of such defects.

A model of osteoblast-osteocyte kinetics in the development of secondary osteons in rabbits.

The kinetics of osteogenic cells within secondary osteons have been examined within a 2-D model. The linear osteoblast density of the osteons and the osteocyte lacunae density were compared with other endosteal lamellar systems of different geometries. The cell density was significantly greater in the endosteal appositional zone and was always flatter than the central osteonal canals. Fully structured osteons compared with early structuring (cutting cones) did not show any significant differences in density. The osteoblast density may remain constant because some of them leave the row and become embedded within matrix. The overall shape of the Haversian system represented a geometrical restraint and it was thought to be related to osteoblast-osteocyte transformation. To test this hypothesis of an early differentiation and recruitment of the osteoblast pool which completes the lamellar structure of the osteon, the number and density of osteoblasts and osteocyte lacunae were evaluated. In the central canal area, the mean osteoblast linear density and the osteocyte lacunae planar density were not significantly different among sub-classes (with the exclusion of the osteocyte lacunae of the 300-1000 µm(2) sub-class). The mean number of osteoblasts compared with osteocyte lacunae resulted in significantly higher numbers in the two sub-classes, no significant difference was seen in the two middle sub-classes with the larger canals, and there were significantly lower levels in the smallest central canal sub-class. The TUNEL technique was used to identify the morphological features of apoptosis within osteoblasts. It was found that apoptosis occurred during the late phase of osteon formation but not in osteocytes. This suggests a regulatory role of apoptosis in balancing the osteoblast-osteocyte equilibrium within secondary osteon development. The position of the osteocytic lacunae did not correlate with the lamellar pattern and the lacunae density in osteonal radial sectors was not significantly different. These findings support the hypothesis of an early differentiation of the osteoblast pool and the independence of the fibrillar lamellation from osteoblast-osteocyte transformation.

Late presentation of a partial median nerve palsy following a Gartland III supracondylar humeral fracture.

A 28-year-old male patient was referred to the Peripheral Nerve Injury Unit at the Royal National Orthopaedic Hospital for evaluation and treatment of a neuropathic type pain he had developed in his right arm. Some twenty years previously, he had sustained a Gartland type III supracondylar humeral fracture with what was thought clinically to be an anterior interosseous nerve palsy. The fracture was reduced and the nerve palsy subsequently recovered with non operative measures. At his subsequent delayed presentation, surgical exploration revealed that the median nerve epineurium was embedded within the bone at the level of the previous fracture. A good clinical result was obtained following neurolysis. The case report highlights a late presentation of median nerve palsy following interposition of the neural structure within the reduced distal humeral fracture site; it shows that delayed surgery can be effective.

Structural pattern and functional correlations of the long bone diaphyses intracortical vascular system: investigation carried out with China ink perfusion and multiplanar analysis in the rabbit femur.

The intracortical vessel system of the rabbit femur has been studied after perfusion of the vascular tree with a water solution of dye (China ink) with multiplanar analysis. This method utilizes the full depth of field of the microscope objectives focusing different planes of the thick cortex. The microscopic observation even if restricted to a limited volume of cortex allowed to differentiate true 3-D nodes (54.5%) from the superimposition of vessels lying on different planes. The network model with elongated meshes preferentially oriented along the longitudinal axis of the diaphysis in his static configuration is not very different from the vascular anatomy depicted in the 2-D traditional models; however, the semi-quantitative morphometric analysis applied to the former supported the notion of a multidirectional microvascular network allowing change of flow according to the functional requirements. Other peculiar aspects not previously reported were cutting cone loops, blind-end and short-radius-bent vessels, and button-holes figures. The network design and node distribution were consistent with the straight trajectory of the secondary remodeling, with the proximal-to-distal and distal-to-proximal advancement directions of the cutting cones and with two main modes of node formation, namely bifurcation of the cutting cone and interception with pre-existing canals. The general organization of the network and its uninterrupted transformation during bone modeling and remodeling suggested a substantial plasticity of the intracortical vascular system capable to adapt itself to the changeable haemodynamic conditions.

The shape modulation of osteoblast-osteocyte transformation and its correlation with the fibrillar organization in secondary osteons: a SEM study employing the graded osmic maceration technique.

Cortex fractured surface and graded osmic maceration techniques were used to study the secretory activity of osteoblasts, the transformation of osteoblast to osteocytes, and the structural organization of the matrix around the cells with scanning electron microscopy (SEM). A specialized membrane differentiation at the base of the cell was observed with finger-like, flattened processes which formed a diffuse meshwork. These findings suggested that this membrane differentiation below the cells had not only functioned in transporting collagen through the membrane but also in orienting the fibrils once assembled. Thin ramifications arose from the large and flat membrane foldings oriented perpendicular to the plane of the osteoblasts. This meshwork of fine filaments could not be visualized with SEM because they were obscured within the matrix substance. Their 3-D structure, however, should be similar to the canalicular system. The meshwork of large, flattened processes was no more evident in the cells which had completed their transformation into osteocytes.

Dietary tryptophan manipulation reveals a central role for serotonin in the anabolic response of appendicular skeleton to physical activity in rats.

Several studies support a serotonin role in the physiological control of bone mass. However, whether serotonin (5-HT) is involved in bone loss due to reduced mechanical stress or unloading is unknown. We investigated the effects of reduced 5-HT tone, induced by tryptophan-free diet, in movement-restraint osteopenia induced by housing mature rats, acclimatised in single cages with a floor area of 1,500 cm(2), in smaller size single cages where their motor activity was reduced. Tryptophan-deficiency significantly worsened movement-restraint-induced bone loss in both femoral metaphysis and diaphysis (DXA analysis) but not at lumbar vertebrae and impaired the mechanical properties of the femur by significantly reducing both cortical thickness and strength strain index (pQCT analysis). Such effects resulted from an impairment of bone turnover with bone resorption exceeding bone formation. Tryptophan-supplemented diet reversed the worsening effects of tryptophan-deficiency on movement-restraint osteopenia. The improvements of both bone mass and strength were associated with an increase of serum osteocalcin and IGF-I, markers of osteoblast activity. In vitro studies in primary cultures of rat osteoblasts suggest that the anabolic action of 5-HT involves the activation of the Wnt/ß-catenin pathway. Serotonin significantly increased the cytoplasmatic ß-catenin protein levels by the inhibition of the enzyme glycogen synthase kinase-3ß, that by phosphorylating ß-catenin promotes its degradation. Our data support a role for 5-HT in the anabolic response of the appendicular skeleton to mechanical loading. We suggest that serotonin might stimulate canonical Wnt/ß-catenin-dependent bone formation to occur.

Morphometry and patterns of lamellar bone in human Haversian systems.

The lamellar architecture of secondary osteons (Haversian systems) has been studied with scanning electron microscopy (SEM) in transverse sections of human cortical bone. Na(3) PO(4) etching was used to improve the resolution of the interface between neighboring lamellae and the precision of measurements. These technical improvements permitted testing of earlier morphometry assumptions concerning lamellar thickness while revealing the existence of different lamellar patterns. The mean lamellar thickness was 9.0 ± 2.13 µm, thicker and with a wider range of variation with respect to earlier measurements. The number of lamellae showed a direct correlation with the lamellar bone area, and their thickness had a random distribution for osteonal size classes. The circular, concentrical pattern was the more frequently observed, but spiral and crescent-moon-shaped lamellae were also documented. Selected osteons were examined by either SEM or SEM combined with polarized light microscopy allowing comparisons of corresponding sectors of the osteon. The bright bands observed with polarized light corresponded to the grooves observed in etched sections by SEM. The dark bands corresponded to the lamellar surface with the cut fibrils oriented approximately longitudinally along the central canal axis. However, lamellae with large and blurred bright bands could be observed, which did not correspond to a groove observed by SEM. These findings are in contrast with the assumption that all the fibril layers within a lamella are oriented along a constant and unchangeable angle. The different lamellar patterns may be explained by the synchronous or staggered recruitment and activation of osteoblasts committed to the osteon's completion.

The surgical treatment of isolated mason type 2 fractures of the radial head in adults: comparison between radial head resection and open reduction and internal fixation.

OBJECTIVES: To compare the outcomes of two different surgical treatments for the management of isolated closed Mason Type 2 radial head fractures. DESIGN: Retrospective study. The Student t test and McPearson chi-square test were used to evaluate whether there was a significance difference between the groups. PATIENTS: Fifty-nine patients with isolated Mason Type 2 radial head fractures. INTERVENTION: Twenty-four patients treated with radial head excision (Group I) and 35 treated with open reduction and internal fixation (Group II). MAIN OUTCOME MEASUREMENTS: Clinical outcomes were assessed using the Broberg and Morrey functional rating scores and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. Orthogonal radiographs were performed on both the elbow and the wrist; these were assessed for the presence of arthritis, heterotopic ossification, and the degree of proximal radial migration. RESULTS: The length of postoperative follow-up was 157 ± 61.84 months (Group I) and 125 ± 39.09 months (Group II). The Broberg and Morrey functional rating score was 86.21 ± 6.10 points and 95.09 ± 4.78 points, respectively. The DASH score was 21.82 ± 6.01 points and 2.81 ± 2.73 points, respectively. Radiologically moderate or severe osteoarthritis was present in the elbows of nine patients in Group I and only two patients in Group II. CONCLUSIONS: Patients with isolated Mason Type 2 radial head fractures treated by open reduction and internal fixation (Group II) had less residual pain, greater range of motion, and better strength than patients treated by radial head excision (Group I). Additionally, Group II had a lower incidence of severe posttraumatic arthritis, which contributed to improved DASH and Broberg and Morrey functional scores. These results support open reduction and internal fixation as the treatment of choice for these fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The possible introduction of anti-osteoporosis drugs as an integrated treatment in total hip arthroplasty.

The anchorage of cementless total hip arthroplasty relies on a direct bone to implant bonding. Several factors including material properties and surface treatment determine the interfacial response of the host bone to a foreign material. Another factor that must be taken into account is the bone remodeling after the prosthesis introduction. Considering this bone remodeling, in the last few years the possibility of using anti-osteoporotic drugs has been introduced as a supplementary and integrated treatment in total hip replacement.

The fibrillar organisation of the osteon and cellular aspects of its development : a morphological study using the SEM fractured cortex technique.

The collagen architecture of secondary osteons was studied with scanning electron microscopy (SEM) employing the fractured cortex technique and osmic maceration. Fibrillar orientation and the change in their direction in sequential lamellae was documented where lamellar formation was ongoing, as well as in resorption pits where osteoclasts had exposed the collagen organisation of the underlying layers. Applying an adaptive stereo matching technique, the mean thickness of matrix layers removed by osteoclasts was 1.36 ± 0.45 µm. It was also documented that osteoclasts do not attack the cellular membrane of the exposed osteocytes. The mean linear osteoblast density in fractured hemicanals was assessed with SEM and no significant differences were observed comparing larger with smaller central canal osteons. These findings suggested a balance between the differentiated osteoblasts that have aligned on the surface of the cutting cone and those that are transformed into osteocytes, because the canal surface is progressively reduced as the lamellar apposition advances.