PubMed Health⌕ Search

Biomedical subjects

L Renzi Brivio

Publications and source records attributed to L Renzi Brivio.

8 recordsLinked to original sources
PubMed1986

Limb lengthening by distraction of the epiphyseal plate. A comparison of two techniques in the rabbit.

We have compared, in rabbits, two techniques of limb lengthening by distraction of the epiphyseal plate using a unilateral external fixation frame. In all cases, 14 mm of symmetrical lengthening without deviation was achieved. With rapid distraction at rates of 1 mm per day (distractional epiphyseolysis) separation of the epiphysis from the metaphysis occurred by day 7, and by day 70 almost complete ossification of the cartilage and the elongated segment was evident. In contrast, slow distraction at 0.25 mm every 12 hours (chondrodiatasis) produced hyperplasia of growth cartilage without any evidence of detachment at 28 days, the end of the distraction period. By day 70 the epiphyseal plate had returned to normal thickness with normal cellular morphology, while the lengthened segment was occupied by ossified tissue. The significance of these findings is discussed.

Animals↗
PubMed1986

Chondrodiatasis-controlled symmetrical distraction of the epiphyseal plate. Limb lengthening in children.

We describe a technique for slow, progressive, symmetrical distraction of the growth plate using a lightweight dynamic axial fixation system. Results are given for the elongation of 40 bony segments in children with limb-length discrepancies and 60 segments in children with achondroplasia or hypochondroplasia. Increases in limb length of up to 36% were obtained in non-achondroplastic and up to 64.5% in achondroplastic patients. There were no nerve or vascular lesions or bony infections and no case required a bone graft. Pin-track complications occurred in only 1.5%.

Achondroplasia↗
PubMed1986

Dynamic axial fixation. A rational alternative for the external fixation of fractures.

Conventional external fixation systems neither inhibit motion at the fracture site sufficiently to permit primary bone healing, nor do they allow sufficient motion to encourage adequate external callus formation. Healing with such systems is therefore prolonged. These methods are usually reserved for the most severe fractures when internal fixation may be contraindicated. A unilateral, dynamic axial fixation system (Orthofix - registered trademark) is described which allows for simple conversion from a rigid to a dynamic mode, and so can be readily adapted to the changing physiological patterns of fracture repair. In 288 fresh fractures a success rate of 94% was achieved, with an average time to healing of 4.4 months. The incidence of pin-track infection was only 0.6%. The contribution which the mechanical and design features of the apparatus make to the results obtained is discussed. It is suggested that the system is capable of extending the range of indications for an externally mounted system to include many cases which would formerly have been treated by internal fixation, plaster cast or traction.

Adult↗
PubMed1984

The treatment of fractures with a dynamic axial fixator.

The results obtained with a lightweight dynamic axial fixator in the treatment of fractures are reported. The apparatus comprises a single bar with articulating ends which clamp self-tapping screws and can be locked at an angle appropriate for axial alignment. A telescopic facility allows ready conversion from rigid to dynamic fixation once periosteal callus formation has commenced. Reduction and controlled distraction or compression are achieved by means of a detachable compressor unit. We treated 288 patients with fresh fractures and 50 with ununited fractures. The success rate for fresh fractures was 94%, with average healing times ranging from 3.4 to 6.5 months. In ununited fractures also, the success rate was 94% with average healing times ranging from 4.7 to 6.5 months. Complications were minimal. The device is versatile and can be applied in an average of 15 minutes. It permits ambulatory fracture care without sacrificing a sound anatomical result.

Adolescent↗