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PubMed1984

Wedge-shaped epiphyses of the knees in two siblings: a new recessive rare dysplasia?

A peculiar form of metaphyseal dysplasia, mainly of the lower limbs, occurred in two male siblings born to healthy, unrelated parents. The clinical and radiological features were short stature, psychomotor retardation, accelerated bone maturation, the limbs and especially the knees showing cup-shaped widening of the ends of the metaphyses and wedge-shaped widening of the epiphyses. This condition does not fit the description of any syndrome reported so far and may therefore be classified as a new recessive dysplasia.

Bone Diseases, Developmental↗
PubMed1983

Kinetics of osteoclast formation: the significance of blood monocytes as osteoclast precursors during 1 alpha-hydroxycholecalciferol-stimulated bone resorption in the mouse.

The significance of blood monocytes as a source of osteoclast precursors was investigated during 1 alpha-hydroxycholecalciferol-stimulated bone resorption in mice. Animals were given three injections of tritiated thymidine at 8 hourly intervals in order to label blood monocytes. The proportion of labelled monocytes was then compared with the proportion of labelled nuclei in osteoclasts, the formation of which was provoked by daily injections of 1 alpha-hydroxycholecalciferol, beginning 48 hours after the first injection of isotope. Although more than 60% of blood monocytes were labelled during the period of peak osteoclast formation, labelling of osteoclast nuclei in the metaphyseal endosteum of the femur never exceeded 8%. These results suggest strongly that the majority of osteoclast nuclei were derived from a source of unlabelled precursors, and that very few osteoclasts were derived directly from blood monocytes. Although few labelled osteoclasts were found, the proportion of labelled spindle shaped cells in the metaphyseal endosteum rose gradually to 16%. It is likely, therefore, that labelled mononuclear cells, possibly blood monocytes, were attracted to the endosteum where they formed a population of tissue macrophages. At this site they may participate in bone resorption, either individually or by providing a local pool of osteoclast precursors.

Animals↗
PubMed1983

Recovery of the rat skeleton from the adverse effects of simulated weightlessness.

A rat model that involves total mechanical unloading of the hind limbs has been used to simulate some aspects of weightlessness. In a previous study, the presence of marked skeletal abnormalities in the proximal tibial and humeral metaphyses of unloaded rats was detected. In the current study, the rats were removed from the model after a 2-week suspension period and allowed to recover for 2 weeks in individual metabolic cages before sacrifice. Tetracycline derivatives were administered on three separate occasions to evaluate radial and longitudinal bone growth. Periosteal bone formation in the tibial diaphysis of suspended animals was significantly depressed during the suspension period but approached control levels during the recovery period. Periosteal bone formation in the humeral diaphysis was not affected by simulated weightlessness. In the proximal tibial and humeral metaphyses, longitudinal bone growth, the amount of mineralized tissue, and the fat content of the bone marrow, all of which were previously determined to be abnormal after 2 weeks of simulated weightlessness, returned to control levels during the recovery period. The previously observed decline in the osteoblast population and increased numbers of osteoclasts adjacent to the growth plate in suspended animals also proved to be reversible at both skeletal sites. This study demonstrates that the skeleton of growing rats is capable of a rapid recovery from the adverse effects of simulated weightlessness.

Animals↗
PubMed1984

Radiographic, macroscopic, and microscopic changes in growth plates of calves raised on hard flooring.

The effect of flooring on the development of physeal and metaphyseal lesions of the limbs was studied in 1- to 5-month-old dairy calves. Calves were allotted to 2 groups. Group I was housed on a clay floor throughout the study and group II was housed on metal slats until weaned and then on concrete. Radiographs of the right thoracic limb of the animals were made 7 times during the experimental period and of the right thoracic and pelvic limbs at necropsy. Selected sections of the physeal regions of the distal part of the radius, metacarpus, metatarsus, and rib were examined microscopically. The physes of the limbs in the 2 groups had eosinophilic streaks and patches which originated in the germinal zone and were associated with blood vessels. These foci varied from small streaks parallel to the chondrocyte columns to multiple horizontal branching patches in which cleft formation and necrosis interrupted the physis, resulting in osseous bridging. Remnants of necrotic cartilage or cartilage containing hypertrophied chondrocytes were located in the metaphysis adjacent to the areas of physeal disruption. Multiple undulations of the physes with variations in thickness and orientation of the chondrocyte columns occurred in the physes of all limbs examined. These areas did not interrupt the physis and were not associated with metaphyseal lesions. The ribs in both groups had focal areas of failure of endochondral ossification characterized by elongation of the hypertrophied zone, accumulation of fibrin and hemorrhage in the zone of provisional calcification, and retention of cartilage within the metaphysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Experimental rickets in broilers: gross, microscopic, and radiographic lesions. I. Phosphorus deficiency and calcium excess.

Day-old broiler chicks were fed diets high in calcium or low in phosphorus for 30 days. Chicks in both groups had similar gross, microscopic, and radiographic lesions. At 2 weeks, the growth-plate degenerating hypertrophied zone (DHZ) and metaphyseal primary spongiosa were lengthened and decreased in radiopacity. Metaphyseal vessels extended to the growth-plate hypertrophied zone (HZ), and osteoid seams were widened. At 3 and 4 weeks, lesions were similar; however, folding fractures were common and cartilage columns of the metaphysis were thinned and replaced with increased woven bone.

Animals↗
PubMed1983

Morphologic and biochemical changes in cartilage of foals treated with dexamethasone.

Epiphyseal and articular cartilages were examined in pony foals treated with intramuscular injections of either 0.5 mg dexamethasone per 100 kg bodyweight daily for 3, 8 or 11 months, or 5.0 mg per 100 kg for 11 months, and in horse foals treated with 5.0 mg per 100 kg for 20 weeks. The proximal femoral growth plates exhibited increased spatial separation between chondrocyte columns, narrowed zones of disorganized columnar and hypertrophic cartilage, abnormal penetration of hypertrophic cartilage by metaphyseal capillaries, retained cartilage in the spongiosa, distal terminal plate formation, transverse trabeculation, chondronecrosis and metaphyseal osteochondrosis dissecans. Destructive articular lesions were observed after 3 months of treatment with 0.5 mg per 100 kg bodyweight. Joint damage originated either at the joint surface or deep within the cartilage. Signs of surface deterioration included edema, fibrillation, enlargement of lacunae, pitting, shredding and erosions of cartilage. Inactivity of articular cartilage growth centers was common, with failure of epiphyseal capillaries to penetrate the lacunae in the calcified cartilage. Chondronecrosis adjacent to the calcification front was accompanied by cartilage ulceration and fracture. Intracartilaginous cysts and subchondral chondroid cysts were also observed. Healing responses included reparative chondrogenesis (focal cartilage hyperplasia), formation of fibrous or fibrocartilaginous "scars," subchondral osteopetrosis and epiphyseal marrow petrosis. Lactate dehydrogenase specific activities per chondrocyte, 35S uptake per cell and glycosaminoglycan contents of articular cartilages were all reduced 55% by 3 months of treatment. This inhibition of articular chondrocyte metabolism initiated cartilage degeneration. Surface destruction and osteochondrosis dissecans followed continued mechanical stress of compromised cartilage.

Animals↗
PubMed1983

External skeletal fixation using methylmethacrylate. Current technique, clinical results, and indications.

External skeletal fixation using self-curing acrylic resin was applied by inserting A-O cortical screws into the diaphyseal region and A-O cancellous screws into the epiphyseal and/or metaphyseal regions. The position of the screws was designed to secure three-dimensional fixation. Points of insertion are selected that avoid infected bone, open wounds, thick muscles, and skin that is relatively mobile during joint motion. After reduction the acrylic resin rather than conventional metal linking devices is used for fixation of the screws. Once the fixation is completed, it is adjustable and so rigid that exercises for joint function are possible. The apparatus is light in weight and sufficiently compact to fit under clothing. In the 204 patients treated by this method, open tibial fractures occurred in 123; nonunion or delayed union in 28; metaphyseal and epiphyseal fractures in 30; femoral fractures in ten children; and miscellaneous fractures and other conditions in 13. Nearly all of the operations were successful. Three patients had refractures after removal of the fixation device.

Adult↗
PubMed1978

Cementum-like bone production in solitary bone cysts. (so-called "cementoma" of long bones). Report of three cases. Electron microscopic observations supporting a synovial origin to the simple bone cyst.

Three cases of simple bone cysts (S.B.C) in association with cementum-like bone production are reported. Analysis of our cases and the 2 previously reported in the literature as so-called cementomas has led us to conclude that the "cementoma" of long bone is not a distinct entity, but merely, a form of S.B.C. associated with a peculiar, poorly cellular form of bone which mimics tooth cementum by light microscopy only. Electron microscopic studies of this substance demonstrate collagen fibers and numerous matrix vesicles which form the initial sites of calcification. Matrix vesicles are a product of osteoblastic activity and are never found in the cementum of the tooth or oral cementum producing tumors. We also report the first ultramiscroscopic observations on the wall of the simple bone cyst and its lining. Two cell types constitute the lining, having features identical to those described for type A and type B synovial cells. Because of this new observation, we believe, the most reasonable explanation for the simple bone cyst is that it represents a congenital "rest" of synovial tissue displaced into the thin, cortical metaphyseal region of bones at the synovial-capsularbone reflection. Its benign nature and slow growth would explain its discovery in early childhood and the marked preponderance of its proximal humerofemoral location dependent upon the fact that these 2 bones have the largest area of capsular to metaphyseal bone reflection.

Adolescent↗
PubMedDate not supplied

[Epiphyseal chondroblastoma. Clinical and anatomo-radiographic aspects].

The clinical radiological and anatomohistological features of fourteen cases of epiphyseal chondroblastoma are described. The seat, origin, and evolution of the tumor are discussed. The diagnosis of the epiphyseal localization is easy, but there are same problems in the differential diagnosis of the epiphyseal-metaphyseal of metaphyseal forms.

Adolescent↗
PubMed1982

Periosteal chondroma. A clinicopathologic study of 23 cases.

The periosteal chondroma (juxtacortical chondroma) is an unusual tumor which usually occurs on the surface of tubular bones in the metaphyseal area. In this study, we reviewed the clinicopathologic features of 22 patients representing 23 instances of periosteal chondroma and discuss the radiologic and histologic features necessary for accurate diagnosis. The characteristic radiologic appearance is of a single cartilaginous mass in the metaphyseal periosteum causing well-defined depression or "saucerization" of the adjacent cortex. The radiologic differential diagnoses include soft-tissue tumors compressing bone, fibrous cortical defect, and periosteal chondrosarcoma or osteosarcoma. Histologic features include lobules of hyaline cartilage with frequent areas of hypercellularity, binucleate chondrocytes, and focal mild cytologic atypia. The histologic features clearly identify the tumor as chondrogenic; however, familiarity with the x-rays may be necessary to recognize the tumor as benign.

Adolescent↗
PubMed1981

Some vagaries of the medial epicondyle.

Roentgenographic data on the maturing epiphysis of the medial epicondyle of the humerus are prone to misinterpretation for the following reasons. First, fractures of the medial epicondyle may not be associated with joint effusion or metaphyseal avulsion fragments. Second, in the medial epicondyle the center of ossification, which lies posteromedial to the distal end of the humerus and is the last of the elbow epiphyses to unite with the humerus, may be quite distant from the humeral metaphysis, and differentiation of this normal characteristic from minimum avulsion is necessary. Also, multicentric ossification, although uncommon, will give the epiphysis a fragmented appearance. Finally, just before ossification of the medial epicondylar epiphysis, on its metaphyseal surface on the distal end of the humerus a sharp, straight sclerotic edge develops.

Child↗
PubMed1978

The activity of the metaepiphyseal chondrocytes in the humerus of growing mammals.

In the postnatal period of development of animals there have been established differences in the length of the distal and proximal metaphyses, as well as in the biosynthesis of sulphated proteoglycans and collagen proteins by chondrocytes. The local peculiarities of the functional and reproductive activity of chondrocytes exert influence upon the histological structure of metaphyses. The locomotive function with its certain supporting-power loads on various joints is supposed to be the main cause for these changes.

Animals↗
PubMedDate not supplied

Changes in the capital growth plate and the proximal femoral metaphysis in Legg-Calvé-Perthes disease.

Studies on about 350 hips treated during the years from 1946 to 1965 for Legg-Calvé-Perthes disease (LCPD) showed that metaphyseal changes regularly appear in this condition. When these changes are extreme, a step-like irregularity appears in the capital growth plate and the bony epiphysis adapts itself to the metaphyseal defect. This phenomenon of step-like progression of changes in the growth plate is seen in other conditions as a consequence of cartilage necrosis. When premature closure of the capital epiphyseal plate occurs in LCPD it may be followed by "overgrowth" of the greater trochanter and a positive Trendelenburg sign. This functional disability may be prevented by apophyseodesis of the greater trochanter if it is performed early enough.

Adolescent↗
PubMed1995

[The significance of blood vessels on both sides of the growth plate].

A new 3-D presentation of the whole vasculature of the epiphyseal growth plate clearly allows for a distinction between arterial and venous sections of the blood circulation. Histological investigations using these processing methods could neither prove the connection between epiphyseal and metaphyseal vessels through the growth plate in newborns nor the concept of an arterial epiphyseal blood supply of the growth plate presented by Trueta. It is rather a question of an arterial metaphyseal perfusion and an epiphyseal venous drainage system.

Animals↗
PubMed1995

Fatigue failure in small diameter tibial nails.

The prevalence of implant failure in small diameter tibial nails has not been well characterized. In a series of 130 tibial fractures stabilized with 8-mm and 9-mm nails, implant failure occurred in 18 fractures (13.8%): 4 nails (3%) broke and 16 (12.3%) screws failed. All nail failures occurred in open, unstable fractures with delayed union, and all of the nails that broke were dynamically locked during the failure. Of the 130 fractures, 128 (98.5%) eventually united. Delayed union, degree of comminution, metaphyseal location, and dynamic locking of unstable fractures contribute to hardware failure. Based on these findings, dynamization could be used to treat delayed union only in axially stable diaphyseal fractures. Exchange nailing is recommended to treat delayed union in comminuted or metaphyseal fractures to prevent hardware failure. Bone grafting should be performed at 6 to 12 weeks for fractures with > 50% bone loss.

Bone Nails↗
PubMed1995

Indirect reduction and composite fixation of extraarticular proximal tibial fractures.

Forty-one extraarticular comminuted proximal tibial fractures were treated during a 7-year period. The fractures were proximal tibial metaphyseal injuries or metaphyseal-diaphyseal junction injuries with extension proximally and distally but not involving the knee joint. All fractures were treated surgically with open reduction and internal fixation using an indirect reduction technique with a lateral plate, and a medial substitution external fixator concomitantly. All fractures were seen for followup until they healed (average healing time, 12.1 weeks). The timing of internal fixation was based on the status of the soft tissue (average time to surgery, 8.5 days after injury). A temporary spanning external fixator was used in 17 (41.5%) fractures to allow for further assessment, demarcation, and improvement of the anterior soft tissues. There were 3 (7%) delayed unions, 1 (2%) malunion, and no nonunions. There were 2 (5%) wound infections and 5 (12%) pin track problems. One postsurgical soft tissue problem was encountered. Through this technique, reliable healing and alignment were achieved in this often difficult fracture pattern, particularly for fractures that were difficult or impossible to treat with an intermedullary nail.

Adolescent↗
PubMed1995

Posttraumatic nonunion of the distal tibial metaphysis. Treatment using the Ilizarov circular external fixator.

Ten nonunions of the distal tibial metaphysis were treated by using the Ilizarov circular external fixator. Original fractures were classified in terms of the Association for the Study of Internal Fixation as AO type A (4 cases), type B (5 cases), and type C (1 case). Six patients had a history of osteomyelitis. Bifocal compression-distraction lengthening osteosynthesis was performed in all cases. Proximal metaphyseal corticotomy was combined with resection and compression of the distal nonunion site in five cases, and compression alone in three patients. Ankle arthrodesis, in addition to nonunion resection, was performed in two patients. Follow-up averaged 48 months (range, 26 to 81). Eight nonunions healed (80%). Limb length was completely corrected in five cases; angular and rotational alignment was corrected to within 5 degrees in seven patients (70%). Based on an objective and subjective scale, the results were considered good-to-excellent in seven cases and poor in three. Despite the high complication rate and relatively low success rate (70%), the use of the circular frame with small-diameter, tensioned wires may provide an alternative method for the treatment of the very difficult problems associated with complex low distal tibial metaphyseal nonunions.

Adult↗
PubMed1994

Chondrodysplasia in five Great Pyrenees.

Five disproportionate, short-limbed, short-trunked (dwarf) Great Pyrenees pups were examined. The mode of inheritance was compatible with a simple autosomal recessive trait, and skeletal radiography revealed flaring of the metaphyses of all long bones and the costochondral junctions of the ribs. Vertebral bodies were poorly ossified and short, and had a beak-like extension on the caudal metaphyseal margin. Vertebral body end-plates were thin and concave, and ossification was abnormal. Three of the 5 dogs were deaf, and 1 had testicular atrophy. Ocular examinations did not reveal any abnormalities. Histologic examination of the growth plates revealed disorganized chondrocyte columns, and chondrocytes appeared to have undergone degenerative changes in the zone of chondrocyte proliferation. Transmission electron micrography of growth plate chondrocytes revealed dilated profiles of rough endoplasmic reticulum.

Animals↗