Search PubMed⌕ Search

Biomedical subjects

J M Guichet

Publications and source records attributed to J M Guichet.

10 recordsLinked to original sources
PubMed2001

Arthrography for reduction of a fracture of the radial neck in a child with a non-ossified radial epiphysis.

A fracture of the neck of the radius when the head is not ossified can be difficult to assess and treat. In a four-year-old child we suspected from the radiographs that there was an O'Brien type-III injury after trauma. Partial manual reduction of the non-ossified radial head was completed using the Métaizeau technique of intramedullary Kirschner (K-) wiring aided by intraoperative arthrography. The child had a full range of movement at the elbow and wrist when reviewed 11 weeks after the injury, three weeks after removal of the K-wire. We suggest that intraoperative arthrography is a useful complement to the Métaizeau technique for successful reduction of fractures of the radial neck in the presence of a non-ossified radial head.

Arthrography↗
PubMed2001

[Progressive limb lengthening with a centromedullary nail versus an external fixator: experimental study in sheep].

PURPOSE OF THE STUDY: Progressive limb lengthening with an external fixator often leads to pin-related complications. A new technique allowing progressive lengthening with a centromedullary nail without external fixation has been developed. This original double-locked device consists of matching male and female components fitted with a continuous thread. Lengthening is achieved via a one-way ratchet system. Twelve back-and-forth movements produce 1.25 mm lengthening. MATERIAL AND METHODS: We tested this new device on 20 sheep and compared results with external fixation lengthening in 20 other sheep. The animals were divided into groups for sacrifice on days 5, 10, 20, 45 and 90. Serial x-ray were obtained for all animals. In the 45-day and 90-day groups, histomorphometric (trichrome goldner coloration and polarized light microscopy) and densitometric studies were also performed. Bone mineral density (BMD) was determined and bone trabecular density (BTD) and trabecular bone volume (TBV) were expressed in percent of bone trabecular surface area. RESULTS: Mean lengthening in the 45-day and 90-day groups was 39 mm for the nail and 20 mm for external fixation (1 mm/day). At 90 days, 3 sheep out of 4 had consolidated radiologically with external fixation and 2 out of 4 with the nail. BMD was slightly better for external fixation (0.811 vs 0.695/cm(2)). This difference could probably be attributed to the greater lengthening obtained with the nail. At 45 days, BMD was the same (0.6 g/cm(2)) for both devices. BTD was nearly two-fold higher for the nail compared with external fixation (59.65% vs 32.61% at 90 days), most probably due to primary bone formation. The histomorphometric study allowed an analysis of the osteoid border. Bone quality obtained in the bone regenerate with the nail was superior to that obtained with external fixation. Primary bone formation resulted from membrane ossification with direct transformation of fibroblasts into osteoblasts. CONCLUSION: This work demonstrated that progressive lengthening can be achieved with a specifically designed centromedullary nail without iterative opening of the operative site. Tolerance to this type of device and quality of the bone regenerate are altogether satisfactory.

Absorptiometry, Photon↗
PubMed1999

[Leg lengthening and correction of deformity using the femoral Albizzia nail].

The albizzia femoral nail allows for lengthenings up to 10 cm. It can be used in achondroplastic patients. Multiplane corrections can be addressed with a special nail (3D-Albizzia) if multiple osteotomies are performed (e.g. for proximal and distal femoral varus). A derotation and a flexion/extension osteotomy can also be associated. IM nailing is suitable for patient with previous external fixators. Surgical planning should be careful. The operation is currently performed percutaneously, with a 1 to 2 cm skin incision for nail insertion, and a 6 mm incision for distal femoral dome osteotomies. CPM machine is applied in recovery room and rehabilitation resumes on day 1, allowing more than 120 degrees of knee flexion by day 1. Ratcheting for gradual lengthening is begun on day 5 at a rate of 1 mm/day. Muscle stretching and strengthening are maintained for one year. In bilateral cases, a preoperative strengthening program is set. A 120 degrees knee range of motion can be maintained all during lengthening. Intramedullary lengthening allows for maintaining muscle and soft tissue suppleness which protects from hyperpressure over joints and from long-term muscle waisting. The Albizzia is currently a good tool once the surgeon get used to its physiotherapy aspect. Previously reported general anaeshtesia for getting the ratcheting is barely needed, when the technique has been done percutaneously and when the full range of knee motion is recovered on day 1 and maintained thereafter.

Adolescent↗
PubMed1998

Periosteum and bone marrow in bone lengthening: a DEXA quantitative evaluation in rabbits.

We quantitatively studied the role of periosteum and bone marrow-endosteum during lengthening in 18 growing rabbits, comparing four surgical procedures: 1) periosteum and bone marrow preservation, 2) periosteum preservation, bone marrow destruction, 3) periosteum destruction, bone marrow preservation, 4) periosteum and bone marrow destruction. An external fixator was set on one femur, the other serving as a control. Distraction began on day 5 and stopped on day 25 (0.25 mm/12 hours). On day 30, femora were harvested with a layer of muscle. Area, bone mineral content and density were measured by dual-energy x-ray absorptiometry. Procedure 2 showed the highest increase in bone mineral content around the elongated callus (127%) compared to procedures: 1 (81%), 3 (25%) and 4 (-8%, i.e., resorption of bone ends). A statistically significant effect on bone formation was observed when preserving (vs. destroying): 1) periosteum, 2) bone marrow (effect observed only around the distraction gap), 3) periosteum and bone marrow in combination. Periosteum alone forms a larger callus, with more mineral content than bone marrow alone, and destruction of both results in the absence of bone formation around the distraction area. Careful preservation of periosteum is essential to bone healing. Formation of bone with a large mineral content does not require bone marrow preservation, but there is an interaction effect on healing between bone marrow and periosteum.

Absorptiometry, Photon↗
PubMed1997

Mechanical characterization of a totally intramedullary gradual elongation nail.

An intramedullary gradual elongation nail (Albizzia) capable of fulfilling the function of traditional intramedullary nails while providing the gradual, controlled distraction of an external fixator was designed for progressive lengthening of lower limbs. In this study, the biomechanics of the gradual elongation nail were compared with several intramedullary nails: Grosse & Kempf, Russell-Taylor, AO, and Laffay. Bending stiffness, torsional stiffness, ultimate bending strength, and torsional strength were determined using the American Society for Testing and Materials standard F383-73 as a guide. The results show that in unextended and elongated conditions, the gradual elongation nail has torsional stiffness (1-5 Nm2) comparable with the AO nail (2 Nm2) and bending stiffness (41-89 Nm2), ultimate bending (246 Nm), and torsional (28-37 Nm) strengths within the ranges obtained for other intramedullary nails (27-105 Nm2, 167-298 Nm, and 2-100 Nm, respectively). Additionally, the low torque required to lengthen the device under a 500 N load (3 Nm) and the low longitudinal stiffness because of the active dynamization system with bimodal load deformation characteristics (80-120 N/mm initial, 600-800 N/mm secondary) produce a device with almost no torsional and longitudinal stress shielding. From a biomechanical point of view, this single, completely implantable device is a safe, viable, and efficacious alternative to external fixation for progressive lengthening of lower limbs.

Biomechanical Phenomena↗
PubMed1997

A modified Kapandji procedure for Smith's fracture in children.

Anteriorly displaced fractures of the wrist can be treated by the Kapandji technique of percutaneous intrafocal pinning with pins inserted through an anterior approach to give good reduction and stabilisation of the fracture. We have modified this technique by placing the pins through a posterior approach which decreases the risks of neurovascular damage. We have used this method to treat six children with distal radial fractures showing anterior displacement or instability. Good anterior stabilisation was achieved. The pins were removed at an average of eight weeks and the patients were then able to return to full activity. This simple technique can be used for unstable fractures after the failure of conservative treatment or in bilateral fractures in adolescents.

Adolescent↗
PubMed1992

[A nail for progressive lengthening. An animal experiment with a 2-year follow-up].

The elongation nail was experimented on 10 pure-breed Romanov ewes aged 9 to 12 month-old. It was implanted in a randomly chosen femur, the other femur being used as a control. After a superior and lateral approach to the femur, drilling and initial distraction averaging 26 mm, the nail was inserted and locked at both ends. Lengthening began at D1 by alternate inward and outward rotation maneuvers exerted on the pelvic limb. One ewe presented an intraoperative hip dislocation, another one unlocked the upper lock, with secondary shortening. The other 8 ewes underwent successful lengthening without apparently suffering (63-mm gain, i.e. 37% at the end of lengthening). Two ewes died at 9 months and their femura presented with a space remaining to fill smaller than 3 mm. Five of the other 6 ewes were followed up for an average of 10 months after bone healing and nail removal, over a total follow-up of 2 years. The femur is modified all over its diaphysis and widened at the level of the regenerated tissue, where cortical bone is thinner but has a normal lamellar appearance. Bone marrow is replaced by trabecular bone filled with fatty marrow. The pathology study of the last of the 6 ewes followed up for 2 years showed a bridge between both sites of incipient regeneration, indicating bone healing. The final gain as compared to the non-operated side is 27%. Progressive lengthening can be performed with an internal fixator in animals. The clinical trial in progress with allow evaluating this technique and establishing its field of application.

Animals↗
PubMed1991

Lower limb-length discrepancy. An epidemiologic study.

Two retrospective epidemiologic studies have examined the incidence and prevalence of significant lower limb-length discrepancy and the number of surgical corrections by lengthening in 1987 in France. The incidence of apparatus prescriptions for asymmetry correction filled was 2.16 per 100,000 population. The prevalence of people using a corrective apparatus was one per 1000 population. The male-to-female ratio was 1.95:1. Because of biases in the study population, the actual incidence and prevalence of significant limb-length discrepancies is likely to be considerably higher. A questionnaire administered to surgeons of the French Orthopedic Society revealed that the majority of surgical lengthenings were performed by large orthopedic teams. In the 418 procedures reported, the tibia was lengthened more often than the femur (ratio 1.1:1). Gradual distraction techniques were used in 89.4% of cases, with the Ilizarov apparatus used in 57.4%, the Wagner apparatus in 20.6%, and the Orthofix fixator in 11.2%. Immediate distraction techniques were used in 7.9% of cases, 85% of which were done on the femur. Average total lengthening was 51 mm for tibia and femur. Average lengthening was greater for methods of gradual distraction (53.5 mm) than for immediate distraction (31.4 mm).

Adolescent↗
PubMedDate not supplied

[Bilateral lengthening of short lower limbs. 26 cases treated with the Ilizarov method].

Gradual distraction with the Ilizarov external fixator was used on 26 patients for short stature. 19 patients complete their program (G1, 64 fixators): average pain is 12 cm for an initial stature of 133 cm; 3 patients stopped their program before end for psychological problems. Surgical procedures included: section of tensor fascia lata (9 cases), lengthening of Achilleus tendon (16 cases), skin debridement around pins (3 cases), modification of apparatus under general anesthesia (53 cases), iterative corticotomy (4 cases in G1) or peroneus section (4 in G1). Healing index was 23 D/cm for femur and 29 D/cm for tibia. Events occurred during the program: 1) mechanicals: 1 pin rupture; 2) bony: 1 delayed healing needing graftng, 3 bone impactions and 11 fractures after fixator removal, 1 axial deviation needing callotasy at fixator removal; 3) nervous and musculary: 12 transitory peroneal nerve lesions, 3 compartment syndromes, 2 proximal sciatic lesion, recovered, and 2 motor palsies; 4) joint lesions: 1 knee stiffness needing an extensive quadriceps release; 5) vascular: 1 deep venous thrombosis; 6) infectious: 10 superficial infections around pins, 4 osteitis and 1 arthritis; 7) cutaneous: 7 scar removals. Lengthening of people with short stature concerns motivated people fully aware of events occurring during a lengthening program which will decrease the initial handicap.

Achondroplasia↗