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Biomedical subjects

D Mainard

Publications and source records attributed to D Mainard.

At least 37 records · Page 2Linked to original sources
PubMed1995

Antivitamin K prevents heterotopic ossification after hip arthroplasty in diffuse idiopathic skeletal hyperostosis. A retrospective study in 67 patients.

We investigated the risk of heterotopic ossification (HO) after total hip arthroplasty in 67 patients, 16 of whom had diffuse idiopathic skeletal hyperostosis (DISH). DISH was diagnosed on chest, dorsolumbar and pelvic radiographs. HO was graded according to DeLee et al. (1976). After a 1.4 year follow-up, 21 patients had HO. The risk of HO was 5 times higher in DISH than in non-DISH patients, but lower in patients receiving antivitamin K than in those receiving other anticoagulant therapy (relative risk 0.2). Our findings lead us to recommend that DISH should be diagnosed preoperatively for preventive therapy. They also suggest a preventive effect of antivitamin K against heterotopic ossification after hip arthroplasty.

Acenocoumarol↗
PubMed1995

[Imaging of osteomedullary infarctions and their complications].

Radiographic, CT, bone scan and MR patterns of the infarcts of the metaphyses and diaphyses of tubular bones and their main complications are presented. Bone marrow infarcts are located in the medullary cavity of long bones. They most often involve the lower limbs. They are commonly associated with necrosis of the epiphyses and have common origin. In contrast to necrosis of the epiphyses, bone infarcts may present specific complications. They are most often detected incidentally, because of their clinical latency. Radiographic and CT changes appear late, showing localized areas of increased density with irregular rims, or sharply demarcated shells of calcification. Earlier changes are demonstrated by bone scan and MRI. MR pattern is characteristic, showing an area of hyposignal on T1- and T2-weighted sequences, with irregular rims, and sometimes small areas of fat signal. Their complications include cystic formation and malignant degeneration (sarcoma and particularly malignant fibrous histocytoma). An unusual complication, infection involving bone infarcts is also presented.

Bone Cysts↗
PubMed1995

[Double use of sural fascio-cutaneous flap with distal pedicle to cover loss of substance of ankle or heel].

The authors report on a case of a distally based fascio-cutaneous flap from the sural region which has been used twice to cover two different cutaneous sites of an ankle. A 50 years old patient underwent a polytrauma including an open fracture of the ankle. The wound at the anterior aspect of the ankle did not heal and the cover by a distally based fascio-cutaneous sural flap was decided and realized successfully. Three weeks later, owing to the development of an ulcer of the heel, it was decided to cover this skin ulceration with the same distally based flap. This second procedure needed a complementary dissection at the bottom of the flap. Twenty days later, the remaining flap was put back and the uncovered donor site was skin-grafted. The two sites covered by the flap healed, without any further complications. They only benefited in the following months of plastic revision to improve their shapes. In the discussion the authors remind the anatomic basis of this distally based flap, described by Donsky and Fogdestam in 1983. They also discuss the other possibilities to cover these two lesions on the same ankle, using others flaps particularly the lateral supra malleolar flap described by Masquelet, the medial plantar island skin flap described by Harrison and Morgan, the lateral calcaneal skin flap described by Grabb and Argenta and the neuro-vascular island skin flap proposed by Masquelet et al. This clinical case emphasizes on the great interest of the distally based sural flap in the cover of the skin defect of the ankle. The flap is easy to raise and offers a great available skin surface, which can be used, as demonstrated by this original case, in two different sites of the ankle.

Ankle↗
PubMed1995

[Macroscopic, histologic and ultrastructural study of 89 prostheses of anterior cruciate ligament excised because of prosthesis failure].

PURPOSE OF THE STUDY: This study concerns the etiology of failed synthetic anterior cruciate ligament (ACL) prostheses, and attempts to identify the primary mechanisms that lead to their premature rupture. MATERIAL AND METHODS: A total of 89 failed and surgically excised ACL prostheses were retrieved from young and active patients (27 +/- 7 years) at various orthopaedic centres in France. Their average duration of implantation was 34 +/- 24 months. They were examined macroscopically, histologically and by scanning electron microscopy (SEM) to determine the model, the manufacturer, the surgical technique used at implantation, the extent of healing, the site of rupture, as well as the morphology of the damage fibers. RESULTS: Seventy two of these explants represented 6 different models. While all 6 were fabricated from polyester fibres, each had a different textile construction, and each were associated with a unique healing and mechanical response in vivo. SEM observations confirmed that abrasion of the textile fibres were a phenomenon common to all models, and were the primary cause of prosthesis failure. Such wear zones were particularly prevalent at the exit of the tibial tunnel and around the femoral condyle. Collagenic infiltration into the synthetic ACL was poorly organized and unpredictable. It did not increase with the duration of implantation. In fact in certain models, it appeared to have caused deterioration and fraying of the textile structure rather than serving as a reinforcing matrix around the prosthesis. DISCUSSION: A synthetic ACL prosthesis is to be preferred for patients who do not have tissue available for autologous ligamentoplasty. Yet none of the synthetic devices examined in the present study were capable of stabilizing the knee over the long term. Among the factors that influenced their failure we found that the three most common mechanisms were flat abrasion against an osseous surface, flexural and rotational fatigue of the fibres, and loss of integrity of the textile structure due to unpredictable tissue infiltration during healing. CONCLUSION: The results of the present study show that none of the current models succeed in replacing the natural ACL. Future improvements may be achieved by developing surgical procedures for implantation combined with a prosthesis made from fibres and textile structures which are more abrasion resistant and promote predictable and controlled tissue infiltration.

Adult↗
PubMed1994

Fungal arthritis due to Pseudallescheria boydii (Scedosporium apiospermum).

Musculoskeletal infections by fungal agents are uncommon conditions. Pseudallescheria boydii is an ubiquitous saprophytic fungus frequently involved in maduromycosis but rarely in septic arthritis. We describe a case of Pseudallescheria boydii destructive suppurative arthritis and osteomyelitis of the knee in an adult Guadeloupean man. Osteoarticular infections due to Pseudallescheria boydii are reviewed.

Arthritis, Infectious↗
PubMed1993

[Scanning electron microscopy and microcrystals in articular diseases].

The value of scanning electron microscopy (SEM) in the study of crystals in articular diseases is underlined in several cases of examination of joint fluid, or crystal deposits in articular or periarticular tissues obtained by percutaneous or surgical treatment with chemical and crystallographic correlations. Apatite crystals. Two deposits of hydroxyapatite of the rotator cuff were studied by SEM, crystallographic techniques and chemical analysis. SEM study showed spherical aggregates of various size. Urate crystals. Three tophi were observed by SEM, with crystallographic techniques and chemical analysis. Their needle-shape and their great size (20 m) were characteristic. Calcium pyrophosphate crystals. In a case of typical clinical and radiological features, examination of joint fluid, with chemical correlation showed shorter and thicker crystals than those or urate. The precise identification of crystals is based on sophisticated crystallographic techniques such as X-ray diffraction, although SEM allows an accurate and quite simple morphologic study, most often sufficient.

Apatites↗
PubMed1992

Acute haematogenous osteomyelitis of the patella revealed by a pathological fracture in multiple myeloma.

A 57-year-old man was followed up for multiple myeloma with no lytic bone lesions. During a septicaema, he presented with a pathological fracture of the patella. Despite a poor haematological status, he received surgical treatment, which allowed diagnosis of haematogenous osteomyelitis of the patella. The outcome was favourable, with a 6-week plaster immobilization after cerclage and 4 months of intravenous antibiotic therapy. This case emphasizes the fact that one well-known cause of bone lesions may lead to an erroneous diagnosis. The successful clinical course suggests that accurate therapeutic management may be discussed in haematological malignancies when intensive-care support is available.

Acute Disease↗
PubMed1992

[Preparation of a polymer named Porimid, and its sterilization].

From a concrete example, the authors remind the interest to envisage the possibilities of sterilization as early as the initial period of a research about biomaterials. Indeed certain kinds of sterilization may be too much aggressive for biomaterials, especially the polymers, whom the structure is so impaired. These biomaterials may become ineffective even dangerous and blight a long time of research. The authors also expose the necessity to respect the good manufacturing practices of laboratory and the rules of hospital hygienics which is indispensable for all the members of the teams which participate to biomedical or clinical researches. A condition for the respect of these rules is the utilization of a common and well understood language between the medical and no medical teams.

Biocompatible Materials↗
PubMed1992

[Risk of infection related to the use of cryopreserved bone grafts from domestic banks].

The authors report their experience of a home bone bank of cryopreserved femoral heads on a period of 3 years. They remind the rules to observe for the harvesting, the storage and the utilization of these allografts, and also the indispensable biological tests (at the moment when the article was written). About their series, the authors remind the risks of infection in relation with the utilization of femoral head from bone bank, which justify a great rigour in the organization and the managing of these home bone bank.

Bone Transplantation↗
PubMed1991

Tenoxicam concentrations in synovium and joint cartilage in humans.

Tenoxicam is an NSAID of the oxicam group. Its distribution in articular tissues was investigated in 12 patients who required total arthroplasty of the hip. They were given tenoxicam 20 mg once daily for 8 to 30 days before surgery. Blood, synovium and cartilage samples were taken concurrently during surgery, about 14 hours after the last tenoxicam dose. The tissues were ground using a freeze grinder. Tenoxicam was assayed by HPLC. Tenoxicam concentrations averaged 6.21 +/- 3.81 micrograms/ml in plasma, 7.56 +/- 4.67 micrograms/g in synovium and 2.05 +/- 1.43 micrograms/g in cartilage. The individual synovium/cartilage ratios ranged from 1.9 to 9.7. Finally tenoxicam exhibited more affinity for its target organ (synovial tissue) than for joint cartilage.

Adult↗
PubMed1991

[Ulnar nerve compression at the elbow caused by synovial cyst of rheumatoid origin].

The authors report on a case of a fifty year old white woman affected by a rheumatoïd arthritis of 3 year duration who develops a progressive ulnar nerve compression by a synovial cyst of the right elbow joint. Surgical procedure confirms the articular and rheumatoïd origin of the synovial cyst and obtains complete healing of the motor and sensory deficit without recurrence of the synovial cyst. Synovial cysts are rare at the elbow joint where they cause as an exception a compression of the ulnar nerve, the authors having found only five cases in the literature.

Arthritis, Rheumatoid↗
PubMed1991

[Study of loosening and wear of total hip prosthesis. Apropos of a series followed-up over 10 years].

After reviewing 30 cases of patients having had a total hip arthroplasty by the Charnley's technique between 1970 and 1978, the authors study the radiographic parameters of the cup and of the femoral stem, using geometric buildings described by Sutherland. On the acetabulum, the inclinaition angle, the medialisation and the wear of the cup were calculated. The varisation of the stem and its migration were looked for on the femur. The presence of a radiolucent line, prosthesis--bone or cement--bone and the importance of peri-articular calcifications, was also noted. The verticalisation of the cup and its anteversion were a pejorative factor. The medialisation was disquieting only if it was associated with a verticalisation. The wear more than 2 mm was noted only in 5 cases; the radiolucent line was pejorative only if it was type cement--bone; the type cement--cup, rare, was of less bad prognostic. On the femur, the most failing was the varus of the stem which determined a loosening most often when it was present. The disquieting radiolucent line was always type cement--bone and was always associated with a bicortical reaction showing a mobility of the stem. In a last part, the authors studied the wear of expanted cups in polyethylene which was different of the fluage. A distinction between the theoretical wear and the clinical wear was made. Photographs in scanning electron microscopy which permit to describe the different types of wear are presented.

Adult↗
PubMed1989

Laser-Doppler versus fluorometry in the postoperative assessment of a cutaneous free flap.

To find the optimal means for monitoring the vascularity of a cutaneous free flap in the postoperative period, we have experimentally compared laser-Doppler velocimetry and fluorometry. Using the rat groin model, five groups were evaluated: 1. flap isolation without division of the pedicle vessels (island flap); 2) flap isolation, division, and repair of the pedicle artery and vein (free flap); 3) flap isolation, with ligation of the pedicle artery immediately or 1 hour later; 4) flap isolation, with ligation of the pedicle vein immediately or 1 hour later; 5) flap isolation, with ligation of the pedicle artery and vein immediately or 1 hour later. The laser-Doppler processes the signal by combination of the root mean square and differential amplification. The fluoroscan gives an index in relation to the fluorescence of a control area. The results obtained with both methods correlated well with findings in clinical situations. However, the laser-Doppler readings were more rapid and sensitive than those with fluorometry. We suggest that laser-Doppler velocimetry is a superior means of monitoring the vascular status of a free tissue transfer or digital replant.

Animals↗
PubMed1989

[Value of the scanner for diagnosing synovial cysts of the hip. Apropos of 2 cases. Review of the literature].

Two cases of synovial cysts of the hip have been observed by the authors. They were extending anteriorly and were developing from the psoas iliac muscle bursa. After a review of the literature it is concluded that this is a rare condition, and that CT scan made the diagnosis much easier. In one case the cyst complicated a rheumatoid arthritis, in the other the origin was not clear. The clinical features and differential diagnoses are recalled.

Aged↗
PubMed1986

Gastric stress ulcer of the rat: relative contribution of the pyloric sphincter, HCO3- bile reflux and mucosal blood flow.

Gastric ulceration has been induced after stress, combining 24 h of fasting and 48 h of restraint in 9 groups of 20 rats with or without a pyloroplasty or a pylorojejunostomy combined with atropine and gastric infusion of NaHCO3 or taurocholic acid. After death or sacrifice at 48 h, ulcer index and blood in the jejunum were determined. Gastric mucosal blood flow was measured semi-continuously by a laser Doppler velocimeter. There were 45% deaths after 48 h of restraint alone, and 70% in the group combining pylorojejunostomy with taurocholic acid. Mortality was lower (p less than or equal to 0.01) pylorojejunostomy alone and more significantly so (p less than or equal to 0.001) when associated with NaHCO3. There was no death when NaHCO3 and atropine were combined with restraint. The mucosal blood flow increased significantly during the first 12 h of restraint in the taurocholic acid group. Both groups with NaHCO3 had mucosal blood flows similar to the controls. Gastric acid and gastric emptying, mucosal ischemia and bile reflux are joint factors inducing gastric stress ulcer. The 100% survival and the low ulcer index after a treatment by atropine and gastric infusion of NaHCO3 suggest that these well-known drugs should be used more frequently.

Animals↗