Level of amputation following failed arterial reconstruction compared to primary amputation--a meta-analysis. (1/2843)

OBJECTIVES: To determine if the level of amputation after failed vascular reconstruction was comparable to the level of amputation after primary amputation. DESIGN AND METHODS: Medline literature search (1975-1996), meta-analysis. RESULTS: The odds ratio of transtibial to transfemoral (TT/TF) amputations was 927/657 = 1.41 (95% confidence limits: 1.278-1.561) in postrevascularisation amputation (PRVA) and 1590/1162 = 1.37 (95% confidence limits: 1.269-1.477) in primary amputation (PA) (p = 0.65). The pooled data show that the number of conversions from transtibial (TT) to transfemoral (TF) amputations due to amputation stump complications were 85/369 (23%) in PRVA against 93/752 (12.4%) in PA (p < 0.01). CONCLUSIONS: We could not detect any difference in TT/TF ratio between PRVA and PA. However, the risk of conversion i.e. reamputation to a higher level is higher after PRVA compared to PA. The chance of having a successful transtibial amputation is approximately 58% for postrevascularisation amputation as well as for primary amputations. An aggressive approach towards vascular reconstruction seems justified.  (+info)

Active signaling of leg loading and unloading in the cockroach. (2/2843)

The ability to detect changes in load is important for effective use of a leg in posture and locomotion. While a number of limb receptors have been shown to encode increases in load, few afferents have been demonstrated to signal leg unloading, which occurs cyclically during walking and is indicative of slipping or perturbations. We applied mechanical forces to the cockroach leg at controlled rates and recorded activities of the tibial group of campaniform sensilla, mechanoreceptors that encode forces through the strains they produce in the exoskeleton. Discrete responses were elicited from the group to decreasing as well as increasing levels of leg loading. Discharges of individual afferents depended on the direction of force application, and unit responses were correlated morphologically with the orientation of the receptor's cuticular cap. No units responded bidirectionally. Although discharges to decreasing levels of load were phasic, we found that these bursts could effectively encode the rate of force decreases. These discharges may be important in indicating leg unloading in the step cycle during walking and could rapidly signal force decreases during perturbations or loss of ground support.  (+info)

Chondrodiatasis in a patient with spondyloepimetaphyseal dysplasia using the Ilizarov technique: successful correction of an angular deformity with ensuing ossification of a large metaphyseal lesion. A case report. (3/2843)

Distraction through the physis (chondrodiatasis) is a controversial technique with unpredictable results. However, it has been used in the past for the lengthening and correction of angular deformities of long bones. We report the case of an 11-year-old patient with spondyloepimetaphyseal dysplasia (SEMD) who presented with a severe recurvatum deformity of the left proximal tibia secondary to collapse of the tibial plateau into a large metaphyseal cystic lesion. Using the chondrodiatasis technique with a percutaneously applied Ilizarov circular frame, we were able to correct this deformity. Surprisingly, healing and ossification of the metaphyseal lesion was simultaneously observed at the end of the treatment, a finding which, to the best of our knowledge, has not been previously reported.  (+info)

The aetiology of congenital angulation of tubular bones with constriction of the medullary canal, and its relationship to congenital pseudarthrosis. (4/2843)

It is suggested that there is a group of cases of congenital angulation of tubular bones in which the lesion is a defect of ossification of the primary cartilaginous anlage and in which neurofibromatosis is not implicated. It appears that in this group the prognosis with regard to the resolution of deformity and the prevention of pseudarthrosis with conservative treatment or relatively simple surgical procedures is better than that in the neurofibromatous type.  (+info)

The clinical manifestations and pathomechanics of contracture of the extensor mechanism of the knee. (5/2843)

Experience with thirty-eight Asian children and adolescents who presented with either stiffness of the knee, genu recurvatum, habitual dislocation of the patella or congenital lateral dislocation of the patella showed that all those disorders were manifestations of contracture of the extensor mechanism, which fell into two groups according to the components involved. In Group I the main components affected were in the midline of the limb, namely rectus femoris and vastus intermedius; these patients presented with varying degrees of stiffness of the knee, or worse, with genu recurvatum. In Group II the main components involved were lateral to the midline of the limb, namely vastus lateralis and the ilio-tibial band; these patients presented with habitual dislocation of the patella, or worse, congenital lateral dislocation of the patella. In both groups untreated patients developed secondary adaptive changes such as subluxation of the tibia or marked genu valgum which made operative procedures more formidable and less effective. Release of the contracture should therefore be performed as early as possible.  (+info)

Limb salvage surgery in bone tumour with modular endoprosthesis. (6/2843)

Thirty-three patients with bone tumours were treated by resection of the growth and reconstruction with a Kotz modular endoprosthesis. The average follow-up was for 50 months, ranging from 14 to 79 months. At the last review, 12 patients (36%) had died due to the tumour and 9 others (27%) had metastases. All 4 patients with proximal tibial reconstruction had poor functional results, due to an extension lag or to knee stiffness. Four of the six tumours of the proximal femur were complicated by local recurrence or dislocation of the hip, and had poor or fair functional results. Of the patients with distal femoral reconstruction, 17 out of 22 had excellent or good functional results. Reconstruction with a modular prosthesis after resection of a tumour gives excellent or good functional results in more than three-fourths of the cases of distal femur reconstruction, but it should be used with caution in the proximal tibia and proximal femur.  (+info)

Spontaneous or traumatic premature closure of the tibial tubercle. (7/2843)

A premature closure of the physis of the tibial tubercle in a young man has given rise to a shortening of the tibia, a patella alta and a reversed tibial slope of 20 degrees with clinical genu recurvatum. After a proximal open wedge tibial osteotomy all three postural deformities could be restored. The etiology of this complex deformity is discussed.  (+info)

Characterization of bone marrow laminins and identification of alpha5-containing laminins as adhesive proteins for multipotent hematopoietic FDCP-Mix cells. (8/2843)

Laminins are extracellular matrix glycoproteins that influence the phenotype and functions of many types of cells. Laminins are heterotrimers composed of alpha, beta, and gamma polypeptides. So far five alpha, three beta, and two gamma polypeptide chains, and 11 variants of laminins have been proposed. Laminins interact in vitro with mature blood cells and malignant hematopoietic cells. Most studies have been performed with laminin-1 (alpha1beta1gamma1), and its expression in bone marrow is unclear. Employing an antiserum reacting with most laminin isoforms, we found laminins widely expressed in mouse bone marrow. However, no laminin alpha1 chain but rather laminin alpha2, alpha4, and alpha5 polypeptides were found in bone marrow. Our data suggest presence of laminin-2 (alpha2beta1gamma1), laminin-8 (alpha4beta1gamma1), and laminin-10 (alpha5beta1gamma1) in bone marrow. Northern blot analysis showed expression of laminin alpha1, alpha2, alpha4, and alpha5 chains in long-term bone marrow cultures, indicating upregulation of laminin alpha1 chain expression in vitro. Laminins containing alpha5 chain, in contrast to laminin-1, were strongly adhesive for multipotent hematopoietic FDCP-mix cells. Integrin alpha6 and beta1 chains mediated this adhesion, as shown by antibody perturbation experiments. Our findings indicate that laminins other than laminin-1 are functional in adhesive interactions in bone marrow.  (+info)