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Biomedical subjects

D Hannouche

Publications and source records attributed to D Hannouche.

At least 19 recordsLinked to original sources

Embedding of bone samples in methylmethacrylate: a suitable method for tracking LacZ mesenchymal stem cells in skeletal tissues.

Considerable research has been focused on the use of bone marrow-derived mesenchymal stem cells (MSCs) for the repair of non-unions and bone defects. To date, the question of whether transplanted MSCs survive and engraft within newly formed tissue remains unresolved. The development of an easy and reliable method that would allow cell fate monitoring in transplant recipients is a pressing concern for the field of tissue engineering. To demonstrate the presence of transplanted cells in newly formed bone, we established a xenograft nude rat model allowing the detection of murine LacZ MSCs in vivo. MSCs were isolated from transgenic lacZ mice, seeded onto bioabsorbable collagen sponges, and transplanted to repair a calvarial defect in nude rats. As a preliminary step, the histological procedure was adapted to optimize the detection of LacZ cells in bone tissue embedded in methylmethacrylate (MMA). Four fixatives and four fixation times were evaluated. Among all the fixatives tested, 2% formaldehyde/0.2% glutaraldehyde at 4C for 4 days gave the best results for X-gal staining at pH 7.4 on both cell cultures and bone explants. All fixatives were effective for immunodetection of beta-gal. In the chimeric LacZ/nude rat animal model, MSCs were detected in vivo for up to 4 weeks after implantation and contributed to the repair and the neovascularization of the bone defect. LacZ is a suitable phenotypic marker to track MSCs in skeletal tissues embedded in MMA.

Animals↗

A meta-analysis of patellar replacement in total knee arthroplasty.

From individual randomized studies it is unclear whether the patella should be replaced during total knee replacement. We did a meta-analysis to provide quantitative data to compare patellar resurfacing with nonresurfacing during total knee arthroplasty. Only randomized, controlled trials reported between January 1966 and August 2003 comparing patellar replacement with patella retention were included for a total of 12 studies. Two reviewers assessed trial quality and extracted data from papers. The outcomes identified were reoperations for patellar problems, anterior knee pain, knee scores, stair climbing, and patient satisfaction. The resurfaced patella performed better, and we found an increased relative risk (defined by the ratio of the risk of the event in the resurfaced group on the risk of the event in the nonresurfaced group) for reoperation, for significant anterior knee pain, and for significant pain during stair climbing when the patella was left unresurfaced. No differences were observed between the two groups for International Knee Society function score, Hospital for Special Surgery score, and for patient satisfaction. Despite these general findings, forming a definitive conclusion is difficult because many confounding factors, such as component design, surgeon experience, and technical aspects of the surgery, might influence the result in a patient.

Activities of Daily Living↗

Trigger finger treatment by ulnar superficialis slip resection (U.S.S.R.).

Surgical release of the A1 pulley for treatment of trigger finger normally produces excellent results. However, in patients with long-standing disease, there may be a persistent fixed flexion deformity of the proximal interphalangeal joint. This is sometimes due to a degenerative thickening of the flexor tendons and may be treated by resection of the ulnar slip of flexor digitorum superficialis tendon. One hundred seventy-two patients (228 fingers) who had undergone this procedure were reviewed at a mean follow-up of 66 months. Mean pre-operative fixed flexion deformity of the proximal interphalangeal joint was 33 degrees. All but eight fingers were improved by surgery and there was an average gain of 26 degrees in passive extension (7 degrees residual fixed flexion deformity) of the proximal interphalangeal joint. Full extension was attained in 141 of the 228 fingers, and in all 101 fingers with a pre-operative loss of passive extension of 30 degrees or less. This technique is indicated for patients with loss passive extension in the proximal interphalangeal joint and a long history of triggering.

Adult↗

[Medical treatment of ocular burns].

Chemical burns, especially alkali burns, can induce severe damage to the eye, not only of its surface, but also of its deep structures. Ocular chemical burns require urgent medical care and sometimes surgery. Medical management of chemical burns of the ocular surface includes controlling the inflammation of the underlying corneal stroma, preserving limbal vasculature, and restoring the limbal stem cell population if necessary, as early as the 3rd week following the injury, which sometimes also requires surgery consisting for the most part of amniotic membrane and/or limbal stem cell transplantation.

Eye Burns↗

Hybrid alumina total hip arthroplasty using a press-fit metal-backed socket in patients younger than 55 years. A six- to 11-year evaluation.

Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) died from unrelated causes. Four hips had revision surgery for either deep infection, unexplained persistent pain, fracture of the alumina head, or aseptic loosening of the socket. The nine-year survival rate was 93.7% with revision for any cause as the end-point and 98.4% with revision for aseptic loosening as the end-point. The outcome in the surviving patients (50 patients, 57 hips) with a minimum five-year follow-up (mean eight years) was excellent in 47 hips (82.5%), very good in eight (14%), good in one and fair in one. A thin, partial, lucent line, mainly in zone III was present in 38% of the sockets and one socket had a complete lucency less than 1 mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis. This hybrid arthroplasty gave satisfactory medium-term results in active patients. The press-fit metal-backed socket appeared to have reliable fixation in alumina-on-alumina hip arthroplasty. The excellent results using cemented fixation of the stem may be related to the low production of wear debris.

Adult↗

[Reconstructive surgery using composite tissue allografts: perspectives from the first clinical cases].

Tissue allotransplantation is defined by the transfer of tissues harvested from a cadaveric donor (in a brain dead condition) and revascularized to a recipient subject. This is based on the mastery of microsurgical techniques and on the induction of a therapeutic immunosuppression for the recipient. The first allografts (flexor tendon systems, knees and femoral diaphysis, hands, nerves, larynx) opened the field of composite tissue allotransplantation (C.T.A.) in reconstructive surgery. Immunosuppressive agents are now efficient enough to prevent the rejection of the allografts. The first patients operated on did not suffer from major or irreversible complications, but some potential side-effects of the immunosuppression remain an obstacle to the development of allografts in reconstructive surgery. The early functional results of the allografts are encouraging but their long term evolution remains uncertain. Some immunological (the chronic rejection) or psychological (the refusal of the graft and of its constraints) phenomenon might curtail the functional, aesthetic and psychological result. Currently considered as an extreme solution to exceptional indications, C.T.A. represents a tremendous hope for the future of reconstructive surgery.

Hand Transplantation↗

In vivo tracking of bone marrow fibroblasts with fluorescent carbocyanine dye.

Recent advances in the field of tissue engineering have culminated in new tissue substitutes that combine a biomaterial and precursor cells. The effectiveness of these materials is generally assessed in animals, but few studies explore the fate of the transplanted cells in vivo, despite its paramount importance for understanding the function of the engineered tissues. Current methods that use reporter genes or chimeric animals are not always well suited to solving tissue-engineering problems. We therefore developed a new method for irreversible labeling of cells to track their fate in vivo. We used a fluorescent lipophilic probe, CM-Dil, that avidly binds to the cell membrane. Human bone marrow stromal fibroblasts could be labeled with 20 microM CM-Dil in 30 min. The CM-Dil was not cytotoxic and did not affect cell proliferation in vitro. Cells could be monitored for up to 30 days when placed in a coral scaffold and implanted intramuscularly or in a bony site. However, the fluorescence intensity decreased roughly in parallel with the number of cell divisions. This fact needs to be taken into account during the design and interpretation of experiments. We believe that this technique is also of interest for other cell types.

Bone Marrow Cells↗

Prevention of wear and osteolysis: alumina-on-alumina bearing.

Alumina-on-alumina bearings in total hip replacement have been used for 30 years. Excellent tribologic properties and extra low debris generation could, in theory, provide an answer to osteolysis. A review of the authors' experience with alumina-on-alumina bearings showed that, except in a few bearings that had been loose for a long time, osteolysis was not a problem. Although the cemented titanium stem and the alumina-on-alumina couple were not a problem, fixation of the socket had to be improved. To improve the socket fixation system and to avoid the use of a cemented titanium stem that may have created problems in the long-term, a new design was introduced in 1997. The current authors present the preliminary results of the first 96 hips with cementless fully-coated hydroxyapatite titanium alloy stems and sockets, 32-mm alumina femoral head, and alumina liner, both held with a Morse taper. Ninety-six consecutive hips in 89 patients (57 males, 32 females) with a median age of 46 years (range, 14-72 years) were analyzed. One socket was revised at 4 months because of poor primary stability in a patient with a severe acetabular fracture. One patient experienced a traumatic fracture of the implanted femur 3 weeks after surgery. The mean followup was 16 months (range, 4-38 months). One patient died from rupture of an aneurysm. Ninety-three hips in 86 patients were assessed regarding the clinical and radiologic ratings. Two patients (two hips) were interviewed by telephone. The Merle d'Aubigné rating system was 18 in 65 hips (59 patients), 17 in 25 hips (25 patients), and 16 in three hips (three patients) mainly related to a previous disability including limp, sciatic palsy, or stiffness. Examination of 93 available radiographs revealed no ostelolysis, no radiolucent lines at the last examination, and no subsidence. The level of excellent results, even in this young population, and lack of osteolysis and wear are encouraging, even if the followup is too short to allow any conclusions to be made.

Adolescent↗

Functional anatomy of the lateral collateral ligament complex of the elbow.

Postero-lateral instability of the elbow joint is a rare clinical condition, commonly related to a disruption of the lateral collateral ligament complex of the elbow. Twenty elbow joint specimens were studied in order to describe the morphologic characteristics of this complex, and to determine the role of its different components in the stability of the elbow. After a morphologic and morphometric investigation, serial divisions of the medial bundle of the lateral collateral ligament were performed, with or without section of the annular ligament and the anterior bundle of the lateral collateral ligament. The anterior and medial bundles of the lateral collateral ligament had close relationships with the annular ligament and a common proximal course. Isolated section of the medial bundle of the lateral collateral ligament induced only minor laxity of the elbow joint. Combined divisions of the medial and the anterior bundles at their humeral insertion, or the medial bundle and the annular ligament at their ulnar insertion resulted in a reproducible subluxation of the ulno-humeral joint. Thus, postero-lateral rotatory stability of the elbow joint is largely maintained by the lateral collateral ligament complex, composed of three elements: the anterior and medial bundles of the lateral collateral ligament, and the annular ligament. In clinical practice, chronic postero-lateral instability is best treated by a ligamentous reconstruction, that must take into account all these anatomic considerations. We report here a new technique of ligamentoplasty using the fascia of the extensor carpi ulnaris muscle.

Aged↗

Silicone oil removal combined with macular pucker dissection: a retrospective review of 14 cases.

PURPOSE: Silicone oil must be removed from the eye to avoid late complications after the surgical management of proliferative vitreoretinopathy (PVR). Macular pucker, frequently observed after retinal detachment surgery, is responsible for visual impairment. The safety of a procedure combining epimacular membrane peeling and silicone oil removal was retrospectively evaluated. METHODS: Fourteen eyes that had previously undergone vitrectomy and silicone oil tamponade for rhegmatogenous retinal detachment with severe PVR, penetrating or blunt trauma, and intraocular foreign bodies were included. Silicone oil tamponade was maintained for a mean period of 30 weeks (range, 12-108 weeks). The removal of silicone oil was combined with the peeling of an epimacular membrane. RESULTS: Mean follow-up after silicone oil removal was 86 weeks (range, 13-234 weeks). The final retinal reattachment rate was 78%. Macular pucker recurred in one eye after a 24-month period. Best-corrected visual acuity improved two lines or more in eight eyes (57%) and reached 20/200 or better in eight eyes (57%) at last follow-up. CONCLUSION: Macular pucker dissection and silicone oil removal can be safely combined. This single procedure can obviate the need for further surgery in eyes that have already undergone multiple operations and allows good visual recovery.

Adolescent↗

[Surgical treatment of retrofoveal choroid neovascularization in multifocal choroiditis].

BACKGROUND: Surgical removal of subfoveal choroidal neovascularization allows visual improvement, especially in young patients. METHODS: Three eyes of 3 patients were prospectively studied. Subfoveal choroidal neovascularization was related to presumed ocular histoplasmosis syndrome. The surgical procedure included vitrectomy, surgical excision of the neovascular membrane, and air tamponnade. RESULTS: Follow-up was 6, 12 and 20 months. Vision improved in 2 eyes. In one case, recurrent extrafoveal neovascularization was treated with laser photocoagulation. DISCUSSION: Surgery seems to be an alternative to photocoagulation in subfoveal choroidal neovascularization in presumed ocular histoplasmosis.

Adult↗

[Value of posterior capsulorrhexis during combined phacoemulsification and silicone oil removal].

Combined surgery with silicone oil removal, phacoemulsification and intraocular lens implantation was retrospectively evaluated in 9 eyes of 9 patients. Visual acuity was better after surgery in 7 eyes, and 8 eyes did not required further posterior capsulotomy during follow-up (10 months). In 2 eyes post-op intraocular inflammation was observed. Redetachment of the retina occurred in one eye. Posterior capsulorrhexis can be done during cataract surgery and silicone oil removal in a vitrectomised eye, without inducing direct complications.

Adult↗