Are surface water characteristics efficient to locate hyporheic biodiversity hotspots?

Location of river-groundwater exchange zones and biodiversity hotspot is essential for a river management plan, especially for Mediterranean karstic rivers. This location is often difficult and time-consuming when long river sectors are considered. We studied a 13 km-long sector of the Cèze River (Southern France) located in a karstic canyon. We compared five indicators of river-groundwater exchanges: longitudinal profiles of temperature, electrical conductivity and 222Rn concentrations in the surface water of the river, chemical characteristics of the hyporheic water and hyporheic biodiversity. Upwelling zones occurred downstream of geomorphological heterogeneities (here at the tail of gravel bars). Surface water chemistry, especially electrical conductivity and 222Rn concentrations, clearly traces large scale gaining sections, which were not associated to valley narrowing but with lateral springs, suggesting a crucial role of the geological structuration of the karstic plateau of Méjanne-le-Clap. Hyporheic water chemistry fits with the large-scale hydrological pattern, but with a high variability corresponding to local heterogeneities. The stygobite fauna (obligate groundwater organisms) and benthic EPTC (Ephemeroptera, Plecoptera, Trichoptera and Coleoptera) occurred preferentially in the gaining sections fed by groundwater, likely because of oligotrophic water and cooler temperature. The spatial distribution of river-groundwater exchange zone and hyporheic biodiversity may be thus predicted using changes in surface water chemistry, especially for electrical conductivity and 222Rn concentrations.

[Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation: a review of 28 cases]. / Greffe de chondrocytes autologues dans le traitement des pertes de substance condylienne du genou: bilan de 28 implantations.

PURPOSE OF THE STUDY: The knee has little capacity for spontaneous regeneration of deep cartilage defects. In 1999, the French Society of Arthroscopy initiated a multicentric clinical trial on autologous chondrocyte transplantation using the technique described by Brittberg and Peterson. The protocol of this prospective study was validated by the ethics committee and all patients provided the informed consent for participation. MATERIAL AND METHODS: Patients underwent surgery in seven hospitals: 28 patients (7 female, 21 male, mean age 28 years, age range 18-45 years). The underlying condition was: osteochondritis (n=14), isolated posttraumatic chondropathy (n=8), chondropathy plus ACL tear (n=6). All patients presented deep condylar cartilage defects (ICRS grades 3 and 4). Mean surface area involved after debridement was 490 mm2 (range 150-1050 mm2). Patients were reviewed two years at least after transplantation for functional assessment and an MRI performed 2 to 3 years after transplantation. Control arthroscopy was also performed in 13 patients with biopsy for histology and immunohistochemistry for 10. RESULTS: Twenty-six patients were reviewed with more than two years follow-up (mean 2 years 9 months). There were no general complications; three patients presented a partial avulsion of the autograft treated arthroscopically and one arthrolysis was performed at six months. Function was improved in all patients but four, but pain persisted in one patient. The mean ICRS score improved from 41 points (19-55 points) to 74 points (54-86 points), for an 80% gain. Follow-up MRI was available for 16 knees: the graft was hypertrophied in 11, at level in 3 and insufficient in 2; marginal integration was good in 10 knees and fair in 6. Items of marginal and subchondral integration had a very high positive predictive value for good clinical outcome. The arthroscopic score was nearly normal (range 8-11) in 8 knees and abnormal (range 4-7) in 5. The Knutsen histological groups according to richness of hyaline cartilage were: group 1 (>60%) (n=1); group 2 (>40%) (n=3), group 3 (<40%) n(=4) and group 4 (bone or fibrous tissue) (n=1). The function scores (r=0.80) and the MRI scores (r=0.76) were correlated with the arthroscopy scores. There was no correlation between the histological findings but the sample size was too small for meaningful analysis. DISCUSSION: The clinical results demonstrate an improvement in more than 80% of knees, findings similar to earlier reports. The arthroscopic and histological results were equivalent to those reported by Knutsen, but less satisfactory than those reported by Bentley or Peterson. Cell injections under a periosteal patch constitute the first generation of autologous chondrocyte grafts. Resorbable matrices loaded with chondrocytes before implantation are under development and have provided promising early results.

Autologous chondrocyte implantation. A review of techniques and preliminary results.

The treatment of deep focal bone and cartilage defects in weight-bearing areas of the knee remains challenging. Autologous chondrocyte implantation is a recently introduced alternative to drilling and mosaicplasty and is gaining ground in France under the impetus of favorable results obtained in other countries in highly selected cases. The technique and preliminary results are discussed herein.

[Implantation of autologous chondrocytes for cartilagenous lesions in young patients. A study of 24 cases]. / Implantation de chondrocytes autologues pour lésions cartilagineuses du sujet jeune. Etude de 24 cas.

STUDY AIM: The aim of this study was to describe the treatment of symptomatic knee cartilage defects on young active patients by autologous chondrocyte implantation and to report preliminary results in 24 patients. PATIENTS AND METHODS: Since April 1996, 24 selected patients underwent 25 implantations in five military hospitals. There were 19 men and five women (all of them practicing sports); mean age was 27. Lesions were localized on left (n = 13) and right (n = 12) aligned and stabilized knees. There were 12 isolated cartilage defects (eight OCD and four posttraumatic) and 13 associated with ligament lesions (n = 8) or multiple and severe lesions (n = 3 indication of salvage). Mean surface of cartilage defects was 6 cm2. Mean preoperative evolution was 11 months and stage was grade IV (Outerbridge) for all. The first step was arthroscopy for classification and biopsy. The second one was implantation after a 3-week delay (for the ex vivo culture) through arthrotomy, under a periosteal flap taken from tibia and sutured on the edges of the prepared defect. Weight bearing was allowed after the 6th week; MRI was performed at 6, 12, 18, 24 months. The follow up was evaluated with three scales: Lysholm 2, Tegner Activity, Cincinnati Knee Rating System. RESULTS: Postoperative complications included: algodystrophy (n = 2) and phlebitis (n = 1). Four patients were revised at 6 months, seven between 6 and 12 months, 11 after. The longest follow-up was 26 months. Results were poor in one patient (salvage). For the others, pain and swelling decreased after 6 months and disappeared after 12 months. CONCLUSION: Autologous chondrocyte implantation used in this senes and in a large international ongoing series seems to be the only procedure allowing a true long-term regeneration of cartilage defects. Some questions remain, on the biological level in relation with the use of some growth factors and the risk of chromosomic abnormalities, and on the economical level because of the high cost of this technique.

The SFA system for assessing articular cartilage lesions at arthroscopy of the knee.

We proposed to establish a system of assessing severity of chondropathy taking into account localization, size, and depth of cartilage lesions. The design of the study was prospective and multicenter. The subjects were 755 patients who had undergone arthroscopy of the knee. Criteria for assessment of severity of chondropathy were as follows: (a) Physician's overall assessment using a 100-mm-long Visual Analogue Scale, and (b) size, grade, and localization of cartilage lesions recorded on a diagram. We used multivariate parametric and nonparametric analyses. The analyses resulted in two systems of assessing severity of chondropathy: SFA scoring for the three compartments of the knee, which is a continuous variable, and SFA grading, which is a semiquantitative variable. These systems seem to be of clinical relevance. However, more studies are required to further validate them and their capacity to detect changes in severity of chondropathy.

[Upper femoral epiphysiolysis in French Polynesia. Hip pain with serious consequences]. / L'épiphysiolyse fémorale supérieure en Polynésie Française. Une douleur de hanche aux conséquences lourdes.

High femoral epiphysiolysis is a frequent disability in French Polynesia, occurring more in obese young people that being a morphotype quite frequent in this geographical area. It is often at the stage of acute epiphysiolysis or fixed coxa vara these patients are examined. At such stage, sequellae are major and evolving to precocious coxarthrosis. It is at a stage of progressive coxarthrosis at the beginning that treatment and recovery are possible without sequellae. Any practitioner has to think about it when confronted to any pain in a hip of teenager, so a surgical treatment, in good conditions could be performed.

[Changes in the peroneal flap and its use in reconstructive surgery of the lower limb. Apropos of an experience of 10 cases]. / Variations sur le thème lambeau péronier et ses applications en chirurgie reconstructrice du membre inférieur. A propos d'une expérience de dix cas.

A peroneal fasciocutaneous flap supplied by the peroneal septocutaneous vessels and raised from the lateral side of the lower leg was reported by Yoshimura in 1983. This flap which can be used as a proximally or distally pedicled or free flap is very useful for leg skin coverage. This flap has a great potential for skin cover and composite reconstruction of the lower limb due to its multiple structural facets (cutaneo-aponevrotic or composite flap), its possible extensions to other vascular territories and the variable geometry of its mode of transfer. 8 reconstructions have been performed. Their indications are described: 4 proximally pedicled flaps (3 with the fibula), 4 reverse-flow island flaps (1 with Soleus and Peroneus longus muscles). The authors stress the importance of preoperative assessment of the feasibility of a given flap which may be limited by post-traumatic, surgical or anatomic modifications. In particular, the uppermost septocutaneous artery which corresponds inconstantly to the "circumflex peroneal artery" can only be visualized by preoperative arteriography. This artery supplies a proximal peroneal flap which can be used as an island or a free flap. We have used this new variety as a free flap in 2 cases and were satisfied with the results. These various clinical applications without any significant complication or flap failure confirm the biological performance and the safe procedure of peroneal flaps.

[Injuries caused by garfish in New Caledonia and its dependencies]. / Les accidents causés par les aiguillettes en Nouvelle-Caledonie et ses dépendances.

Garfish, which are found in the Indo-Pacific ocean areas, have a long spear-like beak with two narrow jaws and small pointed teeth. They often make sudden leaps while swimming, particularly when attracted by bright lights or when frightened by boats or by one of their predators, mainly in warm seasons. Serious injuries may be caused by a fish jumping and its beak piercing part of the body. The surface wound may appear deceptively small and innocent but if the wound is on the chest or abdomen the beak may have penetrated sufficiently deep to cause internal injuries and death may result. Patients may have to be admitted to the hospital for removal of the beak which may remain embedded in a limb.

[Anterior ligamentoplasty of the knee under arthroscopic control]. / Ligamentoplastie antérieure du genou sous contrôle arthroscopique.

In the technique reported here an anterior cruciate ligament of the knee made of Dacron is inserted under arthroscopy, thus avoiding the usual wide tissue damage and delay in recovery. The very small incisions make it possible to install the prosthesis within an isometric, and therefore reliable, framework. Dacron is used alone for patients who underwent several unsuccessful operations on the knee, and Dacron wrapped in fascia lata, as suggested by Mansat, for patients operated upon for the first time. The results are very encouraging, with no post-operative complications, but the future of this technique will depend on the discovery of a better prosthetic material. This approach to reconstruction of the cruciate ligament might be considered a breakthrough in the treatment of chronic laxity of the knee.

[Injuries by marine animals in New Caledonia and dependencies (author's transl)]. / Blessures par animaux marins en Nouvelle-Calédonie et ses dépendances.

Injuries by marine animals present diverse types and forms. The responsible sea-animals resort to many zoological species, vertebrates and invertebrates, ranging from fishes to sponges. The vulnerant processes are also various: the wound being or not associated with envenomation. Venoms are different, according to the species: some ones are only histotoxic and have a local effect around the wound, others are viscerotoxic, giving a generalized and sometimes fatal intoxication. New Caledonia is an archipelago situated in particularly warm waters, and therefore is a privileged area to observe marine animals injuries. These accidents are more frequent in number in Noumea area, but mainly concern newcomers. In other areas, the insular population much in contact with sea because the food it harvests from it, provides many victims. From personal cases and from those recorded in dispensaries and in G. Bourret Hospital of Noumea, the authors describe the main syndromes: --traumas by non venomous marine animals, --traumas by venomous marine animals: --bites --pricks: single or few - multiple and urticant. For each of these syndromes, the responsible animals, their vulnerant apparatus and their modes of action, their symptomatologies and their treatment are given with a practical view.

[Stings by venomous cones observed in New Caledonia and dependencies (author's transl)]. / Les piqûres par cônes venimeux observées en Nouvelle-Calédonie et ses dépendances.

Authors review height cases of stings by venomous cones observed in New Caledonia. They describe the morphology of the venom apparatus of these attracting molluscs and emphasize the severity of the injuries. Prognosis is the worst in children, and Conus geographus is the most dangerous species of the genus Conus. There is no valuable treatment and prevention is the sole protection.

[Treatment by plants of injuries caused by marine animals in New Caledonia. An approach of the indigenous treatment (author's transl)]. / Le traitement par les plantes des blessures par animaux marins en nouvelle-calédonie. Essai d'approche du traitement indigène.

An approach by an ethnobotanist and a surgeon of the indigenous treatment of injuries caused by marine animals in New Caledony. Actually, the indigenous plants used are under pharmaco-chemical study. They seem to have a real efficiency against thermolabiles venoms, but the mechanism of their action is still unknown; there is no proof of any antidote action. Their efficiency may result from their mode of preparation and local application on the wounds, with a physical action neutralizing the venoms by chemical structure destabilization. Plants used to treat wounds caused by predators have demonstrated a good healing effect when associated with logic surgical tactic (wounds left unsutured). Nowadays, and in the expectation of further studies, severe cases require modern treatments with pathophysiologic bases, such as serotherapy when available or resuscitation technics. Antibiotics and surgery are an absolute requirement in case of septicemic condition.

[An external fixation frame in auto-polymerising acrylic resin (author's transl)]. / Fixateur externe en cadre et en résine acrylique auto-polymérisante.

An external fixation frame for the leg is made up of Bonnel pins, strengthened by bands of autopolymerising resin. The experiment shows this apparatus to be solid, reliable and easy to use. The technique of application is extremely simple and the cost low. The indications are the same as those of proven classical fixation devices, which must be preferred for the moment, when possible. Its use is therefore limited, but justified under special circumstances (poorly equipped units far from major centres, war surgery).