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PubMed2004

[Early functional results with the Mayo-hip, a short stem system with metaphyseal-intertrochanteric fixation].

Total hip arthroplasty has become one of the most successful standard procedures in orthopedic surgery. With a more frequent use in young and active patients bone saving procedures become more important. The goal is to save good bone stock for the revision procedure. One example of conservative femoral implants is the Mayo-stem with reported long term results. The stem design allows a metaphyseal intertrochanteric multipoint fixation for primary fixation. The surgical technique is simple. Using a transgluteal approach, the medial preparation of the femoral neck decreases significantly the irritation of the abductor tendons. In a prospective-randomized study, the early functional results with the Mayo-stem were significantly better than the results achieved with a cement-free standard stem. The Mayo-stem may not be indicated for every hip situation. Its use, however, in cases with normal anatomy contributes to save autologeous bone. Therefore, this short stem is a sensible alternative to standard stems.

Adult↗
PubMed2002

A new syndrome of "spondylo-epi-metaphyseal dysplasia: mixed type".

A new type of rare bone dysplasia is described, which shares some common features with spondylo-meta-epiphyseal dysplasia: short limb-abnormal calcification type and lethal metatropic dysplasia. Besides these features, the present case has some additional unusual features. Facial malformation was very obvious and of a different type. The nose and nares were completely flattened. Hypertrophied acetabular bones, round densities on the ilia, premature ossification of many epiphyses and carpal bones, curvilinear calcifications in some joints, fusion of the ischiopubic rami, calcification of many costal cartilages and thick sclerotic base of the skull were a few of the significant findings. On the basis of the clinical and radiological features, the condition has been named "spondylo-epi-metaphyseal dysplasia: mixed type".

Abnormalities, Multiple↗
PubMed2002

Results of proximal metaphyseal fractures in children.

BACKGROUND: The aims of the present study were: determining the extent of the two typical outcomes (valgus deformity and leg overgrowth); examining the extent, limits and duration of possible spontaneous corrections; and analysing the consequences of different types of therapy. METHODS: Metaphyseal tibial fractures in children are rare (incidence 5.6:100,000). Seven children were retrospectively re-examined by their medical records and roentgenograms. The patients' ages at the time of the accident ranged from 1 year 10 months to 10 years 2 months, and the average observation period was 34 months. RESULTS: All the patients experienced a subjective recovery, with the exception of one child who had minor functional problems. All of them were able to move their knee joint freely. Six patients developed a genu valgum (proximal tibia angle between 6 degrees and 16 degrees ); each of them was treated conservatively. Only two patients--both under the age of 5--experienced a partial spontaneous correction. Overgrowth on the side of the fracture was observed in four cases, varying from 0.5 cm to 1.5 cm, most pronounced after complete reduction and stable osteosynthesis. CONCLUSIONS: We recommend surgical correction and osteosynthesis as the preferred method of treatment, even with the increased likelihood of overgrowth. This is based on our observation of valgus deformity occurring in all cases after conservative treatment, with partial remodelling seen only in children up to the age of 5.

Child↗
PubMed1997

Anabolic effect of genistein on bone metabolism in the femoral-metaphyseal tissues of elderly rats is inhibited by the anti-estrogen tamoxifen.

Whether the anabolic effect of genistein on bone metabolism in the femoral-metaphyseal tissues of elderly rats is inhibited by the anti-estrogen tamoxifen was investigated in vitro. Bone tissues were cultured for 24 h in the medium containing either vehicle or genistein. The presence of genistein (10(-6) and 10(-5) M) caused a significant increase in calcium content, alkaline phosphatase activity and DNA content in the bone tissues. The effect of genistein (10(-5) M) in increasing bone alkaline phosphatase activity and DNA content was equal to the stimulatory effect of 17 beta-estradiol (10(-10) and 10(-9) M) on the bone components. The genistein effect was not significantly enhanced by the presence of 17 beta-estradiol (10(-10) and 10(-9) M). The anti-estrogen tamoxifen (10(-7) M) completely blocked the effect of 17 beta-estrogen in increasing bone alkaline phosphatase activity and DNA content. The genistein (10(-5) M)-induced increases in bone alkaline phosphatase activity and DNA content were completely abolished by the presence of tamoxifen (10(-7) and 10(-6) M), although tamoxifen itself had no effect on the bone components. The present study demonstrated that the anabolic effect of genistein on bone components is inhibited by anti-estrogen tamoxifen. The effect of genistein may be mediated through estrogen-like action.

Aging↗
PubMed1998

Novel missense mutation resulting in the substitution of tyrosine by cysteine at codon 597 of the type X collagen gene associated with Schmid metaphyseal chondrodysplasia.

Schmid metaphyseal chondrodysplasia (SMCD) is one of the most common forms of the osteochondrodysplasias. Mutations or deletions in the COL10A1 gene that encodes type X collagen have been shown to cause this disorder. Most of the gene mutations and deletions are located in the non-collagenous carboxy (C)-terminal (NC1) domain. We describe a novel missense mutation in a patient with SMCD that leads to the substitution of Tyr at codon 597 by Cys in the NC1 domain. Sequence analysis indicated that the proband was heterozygous for the mutation. Her parents were homozygous for the normal sequence, indicating the de-novo occurrence of this mutation.

Adult↗
PubMed1985

Effect of an adrenocorticotropin analogue, ACTH 1-17, on DNA synthesis in murine metaphyseal bone.

The effects of injections of a synthetic adrenocorticotropin (ACTH 1-17, Synchrodyn) on the rate of DNA labeling in the metaphyseal bone of CD2F1 mice were tested on a chronopharmacological dosing schedule. Groups of mice that had been conditioned to a 12-hr light/12-hr dark schedule were injected at one of six different timepoints, 4 hr apart, during a single 24-hr span with either a low (0.02 I.U./kg) or a high (20 I.U./kg) dose of ACTH 1-17. Control groups received injections of a placebo at corresponding timepoints. Subgroups of mice were injected with [3H]thymidine ([3H]Tdr) to follow the changes in DNA labeling in the proximal tibial metaphysis at 15 min and 2, 4, 8, 12 and 24 hr after ACTH 1-17 or placebo treatment. All mice were injected with the isotope 30 min before killing, except for those killed 15 min after Rx administration where the isotope had been injected 14 min before killing. The data were analyzed both by analysis of variance and by the cosinor method, the latter of which tests the fit of a 24-hr cosine curve to the data. The effect of ACTH 1-17 on the target cell population was dependent not only upon the dose but upon the time of administration. Both doses exerted time-dependent action, ranging from stimulation to inhibition of DNA labeling. Inhibition was noted when the ACTH 1-17 was administered at 2 hr after the beginning of the daily dark span when nocturnal animals become active. When administered at this circadian stage, the larger dose in particular was associated with an inhibition of DNA labeling lasting for 24 hr. The inhibitory effect was much shorter when the same dose was injected 4 hr earlier. Moreover, the large ACTH 1-17 dose had a stimulatory effect lasting for 24 hr when it was administered 2 hr after the onset of the daily light span, with a much shorter stimulation following administration of the large dose at 6 hr after the beginning of the daily dark span. A circadian stage-dependent stimulation or inhibition of DNA labeling at 2 or 14 hr after light onset, respectively, was thus complemented by an initial inhibition followed by stimulation and vice versa at 10 and 18 hr after light onset respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenocorticotropic Hormone↗
PubMedDate not supplied

The skeletal effects of colony-stimulating factor-1 in toothless (osteopetrotic) rats: persistent metaphyseal sclerosis and the failure to restore subepiphyseal osteoclasts.

Toothless (tl), one of four osteopetrotic mutations in the rat, is characterized by few osteoclasts, undetectable bone resorption, and failure of correction by bone marrow transplantation. We recently reported that CSF-1 treatment improves these skeletal problems but that metaphyseal sclerosis persists. In the present study we demonstrate that optimal reduction of the skeletal sclerosis in tl rats following CSF-1 treatment has lower and upper dosage thresholds and that skeletal sclerosis returns after CSF-1 withdrawal. Osteoclasts increase significantly in tl rats after CSF-1 treatment, but compared to untreated normal littermates, histochemical staining for characteristic enzymes and osteoclast number is reduced and no osteoclasts appear in the subepiphyseal areas of long bones. These data are interpreted to mean that there are dosage limits to the beneficial skeletal effects of CSF-1, that persistent sclerosis is related to the failure to restore subepiphyseal osteoclasts, that osteoclast or progenitor populations may be deficient or differ in their responses to CSF-1, and that the defect in tl rats is not merely lack of a circulating, biologically active form of CSF-1.

Animals↗
PubMed1995

Mutations in collagen genes resulting in metaphyseal and epiphyseal dysplasias.

Genetic mapping and positional cloning of genes, in which mutations lead to osteochondrodysplasias in humans and mice, combined with studies of transgenic mice with mutations in cloned genes, is providing novel and exciting insights into the molecular mechanisms of cartilage and bone development and growth as well as the basis for a variety of osteochondrodysplasias. Studies of mice with targeted disruption of c-src and c-fos have shown that these two genes have essential roles in the function and differentiation of osteoclasts. Combined mouse and human studies demonstrate that a unique extracellular matrix molecule (collagen X) in the mineralizing hypertrophic zone of growth plates is essential for normal growth plate function. Mutations in this molecule cause metaphyseal chondrodysplasia type Schmid (MCDS) in humans. Identification of the gene causing autosomal recessive chondrodysplasia in mice demonstrates that the quantitatively minor fibrillar collagen XI is essential for the cohesive properties of cartilage and the normal differentiation and spatial organization of chondrocytes in growth plates. Finally, mutations in all three collagen components of cartilage fibrils, collagens II, IX, and XI, have been found to cause a spectrum of clinical disorders, ranging from severe, perinatal lethal, osteochondrodysplasias to extremely mild conditions presenting themselves as a genetic predisposition to osteoarthritis.

Animals↗
PubMed2006

Treatment of distal tibial metaphyseal fractures: Plating versus shortened intramedullary nailing.

BACKGROUND: Fractures in the distal tibial metaphysis are more complicated to treat than diaphyseal fractures. We compared treatment with plating to treatment with shorted intramedullary (IM) nailing. METHODS: Patients with AO type 43A fractures were treated with plate fixation (group A, n=14) or shortened IM nailing (group B, n = 13). We compared postoperative radiographic deformities, functional results (Iowa ankle scores), and symptoms (Olerud and Molander ankle scores). RESULTS: All fractures had healed at final follow-up (mean, 33 month). Mean union times were 27.8 week (range, 18-36 week) in group A and 22.6 week (range, 18-30 week) in group B (P<0.05). Mean postoperative valgus angulations were larger in group B (3.7 degrees ) than in group A (0.5 degrees ) (P<0.05). However, malunions did not differ between groups (P<0.05). Functional results and postoperative symptoms were similar. CONCLUSIONS: Both plate fixation and shortened IM nailing were effective for treating distal tibial metaphyseal fractures.

Adult↗
PubMed2000

Dia-metaphyseal distal tibial fractures--treatment with a shortened intramedullary nail: a review of 15 cases.

Fifteen patients were reviewed retrospectively with distal tibial fractures treated with a reamed intramedullary nail which had approximately 1 cm removed just distal to the lowermost locking screw. There were 15 patients (nine males and six females). All patients had returned to normal activities of daily living. Eleven patients could perform all leisure activities with no symptoms and three had only minor discomfort, which did not preclude sport. All fractures united, 12 uneventfully and three after a secondary surgical procedure. Three patients had malalignment defined as varus-valgus angulation or recurvatum of 5 degrees or greater. Whilst technically challenging, intramedullary nailing for dia-metaphyseal distal tibial fractures represents a safe and reliable method for managing these injuries. This represents the first report in the English Language literature specifically examining treatment with a shortened tibial nail.

Adult↗
PubMed1999

The unreamed tibial nail in the treatment of distal metaphyseal fractures.

In recent years biological surgical solutions have been recommended in cases of distal tibial fractures, with the aim of reducing damage to soft tissues and to bone vascular supply. Between the years 1991-1995, 52 patients suffering from fractures of the distal tibial metaphysis were treated in our department with an unreamed tibial nail (UTN). Fractures were categorized in accordance with the AO Classification. 32 fractures had no articular involvement (43A1, 43A2, 43A3) and 20 included intra-articular extension (43C1, 43C2). 32 fractures had significant metaphyseal comminution (43A2, 43A3, 43C2). 12 were open fractures. All the fractures were treated by means of UTN using distal locking. In 13 patients an additional percutaneous interfragmentary fixation was also applied. 22 patients underwent an additional operation in order to facilitate bone union (dynamization, bone grafting and/or fibulectomy). In 50 of the 52 patients the fracture united with a very good range of knee and ankle motion. In 2 patients non-union with breakage of the UTN occurred and in two open fractures post-operative infections were observed. Our experience with the treatment of fractures of the distal tibia, including intra-articular fractures with no comminution, points at an excellent functional outcome with a low incidence of complications.

Adult↗
PubMed2002

Impaction grafting with morsellised allograft and tricalcium phosphate-hydroxyapatite: incorporation within ovine metaphyseal bone defects.

An ovine model was used to investigate the in vivo properties of impacted tricalcium phosphate-hydroxyapatite (TCP-HA) aggregates, varying in chemical composition (ratio of TCP to HA) and particle size distribution (8 versus 3 particle size ranges). All pellets were impacted to a standard compactive effort. Eight sheep underwent implantation of pellets in 4 metaphyseal defects in both rear limbs. Treatment groups consisted of: (1) allograft (clinical control). (2) 50/50 allograft/80% HA/20% TCP in 8 particle size ranges, (3) 50/50 allograft/80% TCP/20% HA in 8 sizes and (4) 50/50 allograft/80% HA/20% TCP in only 3 sizes of particles. Healing of defects was evaluated at 14 weeks with computed tomography, histology and histomorphometry. The computer tomography (CT) density measured in all defects containing synthetic agents was higher than in defects filled with allograft alone (p<0.01). Defects containing 8 sizes of 80% HA/ 20% TCP granules (group 2) achieved lower histological scores and contained less bone than the clinical control (p<0.05), whereas groups 3 and 4 did not differ from the control. Although all synthetic agents were osteoconductive, our results suggest that increasing the ratio of TCP over HA and limiting the number of particle size ranges to 3 instead of 8 improve the performance of impacted aggregates as graft expanders. Evaluation under loading conditions of morsellised allograft expanded with 80% TCP/20% HA (BoneSave) in 3 particle size ranges is warranted.

Animals↗
PubMed1998

A mild form of pseudoachondroplasia: minimal epi-metaphyseal involvement of long bones.

A problem in diagnosing pseudoachondroplasia (PSACH) is that the pathognomonic changes of vertebral bodies invariably disappear around the age of 10, and an adult case might subsequently be misdiagnosed as MED, Fairbank type, though the latter is less severe than PSACH. We present a Japanese girl (follow-up, 3-10 years of age) whose epi-metaphyseal involvement of long bones was minimal and whose height was +2 S.D. of standard for PSACH in spite of the typical changes of the vertebral bodies. She might not have been diagnosed only as PSACH but also as MED, Fairbank type, after disappearance of the typical vertebral body changes because of the apparent lack of stubby fingers. Since the overlap of PSACH and MED has recently been discussed from the viewpoint of molecular biology, study of the spectrum of clinical features of PSACH is important.

Achondroplasia↗
PubMed2003

A resorbable porous ceramic composite bone graft substitute in a rabbit metaphyseal defect model.

The success of converted corals as a bone graft substitute relies on a complex sequence of events of vascular ingrowth, differentiation of osteoprogenitor cells, bone remodeling and graft resorption occurring together with host bone ingrowth into and onto the porous coralline microstructure or voids left behind during resorption. This study examined the resorption rates and bone infiltration into a family of resorbable porous ceramic placed bilaterally in critical sized defects in the tibial metaphyseal-diaphyseal of rabbits. The ceramics are made resorbable by partially converting the calcium carbonate of corals to form a hydroxyapatite (HA) layer on all surfaces. Attempts have been made to control the resorption rate of the implant by varying the HA thickness. New bone was observed at the periosteal and endosteal cortices, which flowed into the centre of the defect supporting the osteoconductive nature of partially converted corals. The combination of an HA layer and calcium carbonate core provides a composite bone graft substitute for new tissue integration. The HA-calcium carbonate composite demonstrated an initial resorption of the inner calcium carbonate phase but the overall implant resorption and bone ingrowth behaviour did not differ with HA thickness.

Animals↗
PubMed1986

Tracheobronchomalacia in an adult with metaphyseal chondrodysplasia.

Anaesthetic complications such as obstruction of airways by submucosal cartilage-bone protuberances, immobility of the neck or instability of the atlanto-axial joint have been described earlier in paediatric patients with congenital osteochondral disorders. This report concerns a case in which tracheal collapse due to tracheobronchial malacia in an adult patient with metaphyseal chondrodysplasia evidently caused severe ventilatory difficulties in the induction of anaesthesia. The management of the patient on three subsequent occasions is described. During the first operation, support of the upper respiratory tract was performed. For this procedure, awake tracheal intubation with local anaesthesia applied to the larynx, vocal cords and trachea was used. After surgical correction of the bronchus of the right upper lobe and the stem bronchus, subsequent anaesthesias for surgical treatment of scoliosis could be conducted safely. The possibility of co-existing tracheobronchial malacia in patients with osteochondrodysplasias should be considered and tracheal intubation under local anaesthesia is recommended.

Adult↗
PubMed1998

Production of cartilage collagens during metaphyseal bone healing in the mouse.

Small defects of unfractured bone are believed to heal without a cartilaginous intermediate. We have determined the extent of cartilage production in an experimental model of metaphyseal bone repair involving defects in both cortical and cancellous bone, but no fracture. Northern analyses revealed the presence of mRNAs for type X and II collagens in the repair tissue. Immunohistology confirmed subperiosteal deposition of both collagen types adjacent to the defect. While the mRNAs for the two collagen types peaked by one week of defect healing, immunodetectable type X collagen was not observed until the second week. The data suggest that reactivity of periosteum and activation of chondrogenesis and subsequent endochondral ossification programs are involved in murine bone repair regardless of defect type.

Animals↗