Emerging organic compounds as markers of the degradation of groundwater qualitative and quantitative equilibrium in a context of rapid urban expansion.

With the neo-metamorphosis of the residential landscape worldwide and sluggish sanitation strategies in urban environments, rudimentary on-site sanitation systems remain commonly used, especially in developing countries, despite the risks of groundwater contamination. The effective management of such water resources relies on assessment of the sensitivity of anthropized aquifers to man-made impact, including groundwater behavioural alteration, in terms of both quality and quantity. Associated with tracking of changes in land use, this study proposes an approach involving emerging organic contaminants (EOCs) as indicators of the alteration of groundwater balance due the exposure of shallow aquifers to the risks of infiltration of untreated wastewater from soak pits. This methodology was applied to the shallow aquifer beneath the urban agglomeration of Grand-Sfax (Tunisia). Combined with an updated follow-up of groundwater piezometric fluctuations in relation with inputs from surface contamination sources, the spatialisation of contamination levels by EOCs provided a clear delineation of the most impacted aquifer zones. This approach revealed a significant link between the continuous rise in piezometric levels by contributions from untreated inputs and the accumulation of high levels of contamination in groundwater. The understanding of EOC underground pathways allowed the determination of the fates and processes responsible for the diffusion of contamination throughout the studied aquifer. The ability of groundwater to reflect population life style and the use patterns of such organic molecules was also assessed. Besides revealing the legacy of persistent contamination, this approach involving EOCs as tracers with different levels of persistence provided a spatial observation of the aquifer exposure to continuous contamination processes. This approach made it possible to develop a conceptual presentation of aquifer vulnerability to urban pressures and to predict the effects of subsequent expansion of unplanned urbanisation on groundwater quality.

A critical assessment of widely used techniques for nitrate source apportionment in arid and semi-arid regions.

The assessment of nitrate pollution origin using stable isotope techniques is a fundamental prerequisite for the application of sustainable groundwater management plans. Although nitrate pollution is a worldwide groundwater quality problem, existing knowledge on the origin of nitrate pollution in arid and semi-arid regions is still scarce. Using the example of the Grombalia aquifer (NE Tunisia), this work summarizes the main strengths and constraints of multi-isotope techniques targeting at nitrate source identification and apportionment The results highlighted that, even in the case of well-established methodologies, like those of isotope hydrogeochemistry (δ15NNO3, δ 18ONO3 and δ 11B) and mixing modelling for source apportionment, it is fundamental to take into account regional and local end-members to avoid biased data interpretation and to fully exploit the potential of such accurate tools.

Integrated socio-hydrogeological approach to tackle nitrate contamination in groundwater resources. The case of Grombalia Basin (Tunisia).

Nitrate contamination still remains one of the main groundwater quality issues in several aquifers worldwide, despite the perduring efforts of the international scientific community to effectively tackle this problem. The classical hydrogeological and isotopic investigations are obviously of paramount importance for the characterization of contaminant sources, but are clearly not sufficient for the correct and long-term protection of groundwater resources. This paper aims at demonstrating the effectiveness of the socio-hydrogeological approach as the best tool to tackle groundwater quality issues, while contributing bridging the gap between science and society. An integrated survey, including land use, hydrochemical (physicochemical parameters and major ions) and isotopic (δ15NNO3 and δ18ONO3) analyses, coupled to capacity building and participatory activities was carried out to correctly attribute the nitrate origin in groundwater from the Grombalia Basin (North Tunisia), a region where only synthetic fertilizers have been generally identified as the main source of such pollution. Results demonstrates that the basin is characterized by high nitrate concentrations, often exceeding the statutory limits for drinking water, in both the shallow and deep aquifers, whereas sources are associated to both agricultural and urban activities. The public participation of local actors proved to be a fundamental element for the development of the hydrogeological investigation, as it permitted to obtain relevant information to support data interpretation, and eventually guaranteed the correct assessment of contaminant sources in the studied area. In addition, such activity, if adequately transferred to regulators, will ensure the effective adoption of management practices based on the research outcomes and tailored on the real needs of the local population, proving the added value to include it in any integrated investigation.

Elderly patient's mortality and morbidity following trochanteric fracture. A prospective study of 100 cases.

BACKGROUND: Trochanteric fractures are a major source of mortality, morbidity and functional impairment in the elderly. Morbidity is closely related to the degree of instability and comminution and is substantially influenced by the quality of reduction and internal fixation. Advanced age and associated co-morbidities are two decisive factors of mortality secondary to trochanteric fracture. OBJECTIVES: This prospective study examined the epidemiological profile of trochanteric fractures and assessed mortality and morbidity with the aim of establishing management guidelines and improving prevention strategies. MATERIAL AND METHODS: One hundred patients were included; 60% were male. Mean age was 76 years (range, 60-96 yrs). One, or more than one, co-morbidities were present in 68% of cases. The fractures were caused by a simple fall in 90% of cases. Fractures were classified according to the criteria of Ramadier and the ones of Ender. Sixty-five percent of these fractures were unstable. A dynamic hip screw was systematically used as the standard means of internal fixation. RESULTS: Anatomic and functional results were analyzed in 82 patients (18 had died within the first year following fracture occurrence). Mean follow-up period was 24 months (range, 12-36 months). Bone healing was achieved in 96% of cases. There were numerous postoperative complications (four cases of thromboembolism, fourteen immobility-related complications, two infections, six secondary displacement combined to loss of fixation, four non-unions, and nine malunions). At 2 years follow-up, 28 patients had died. Mortality was strongly correlated with older age (over 90 years), associated co-morbidity and fracture instability. Good functional outcomes (72%) correlated with younger age (60-74 years), fracture stability, adequate reduction and internal fixation. DISCUSSION: In stable trochanteric fractures, osteosynthesis by dynamic screw-plate is more effective than alternative techniques (blade-plate, nail-plate, Ender nail or even trochanteric nail). In unstable trochanteric fractures, delayed weight-bearing should be preferred to avoid mechanical complications. In fractures that are unstable or extend far below the lesser trochanter, trochanteric nailing is indicated since providing enhanced stability, but sometimes at the cost of insufficient reduction. The treatment objective should be the complete resumption of weight-bearing as early as possible with the fewest possible complications. Prevention consists in detecting and treating osteoporosis and countering the causes of falls in elderly subjects (muscular reinforcement and correction of neurosensory deficit). LEVEL OF EVIDENCE: Level III: Prospective diagnostic study.

[Systematic circumferential (360 degree) decompression treatment of major arthrotic cervical stenosis]. / Abord circonférenciel (360 degrees) systématique dans le traitement des sténoses cervicales arthrosiques majeures.

PURPOSE OF THE STUDY: Worsening and irreducible evolution of neural involvement in cervical stenosis requires cord decompression. Different techniques have been proposed. We associated a dual posterior then anterior approach to achieve 360 degrees decompression. We evaluated results on the basis of neurological and mechanical outcome. MATERIAL AND METHODS: Twenty-eight patients, 16 men and 12 women, mean age 60.2 years (range 40-82) underwent surgery between 1989 and 1999 for severe cervical canal stenosis. Patients were referred for neurological symptoms: 20 for radicular symptoms (8 pain, 11 motor deficit, 12 sensitive deficit). Fifteen patients presented myelopathic symptoms. Pyramidal syndrome in 11 and tetraparesia in 3. Neurological involvement was scored according to Nurick (average 1.74) and JOA (average 12.6). Pain was scored on the Robinson scale. Levels to decompress were identified on static and dynamic plain x-rays, CT scans and MRI. Myelography was rarely used (first case only). MRI demonstrated preoperative myelomalacia in 5 patients and syringomyelia in 2. The surgical technique for 360 degrees fusion involved two steps, performed with a 1-week interval for 12 patients and during the same procedure for the others. The first approach was posterior enabling spine fixation with bilateral Roy-Camille plates and decompression by laminectomy using the lobster shell technique. The anterior approach consisted in corpectomy with the Simmons technique (22 cases or multilevel interbody fusion according to Robinson. Iliac bone grafting was used in all but one patient who had a fibular bone graft. Mean follow-up was 18.5 months (6-78). RESULTS: Neurological improvement was 1.74 to 0.92 on the Nurick sclae and from 12.6 to 15.2 on the JOA scale at last follow-up. Fusion was obtained in all cases. There were 2 cases of neurological worsening and one transient dysphagia. Operative bleeding for the two steps was 700 ml (150 ml for the posterior procedure and 400 ml for the anterior procedure). CONCLUSION: 360 degrees arthrodesis for severe cervical canal stenosis provides a satisfactory solution to mechanical problems and substantial neurological improvement. Fusion is regularly obtained without complementary anterior instrumentation. Neurological improvement is correlated with disease duration and the degree of deficit at onset. Anteroposterior decompression and 360 degrees fusion provide cure for all the components of stenotic disease. The dual approach is indicated in severe cases with cord involvement as recognized by myleopathic clinical manifestations and on the MRI.

[Congenital hypoplasia of lumbosacral articular process: report of a case, review of the literature, and therapeutic proposition]. / Hypoplasie congénitale d'un massif articulaire lombosacré: rapport d'un cas, revue de la littérature et proposition thérapeutique.

Congenital hypoplasia of the lumbosacral process is an uncommon cause of recurrent lumbalgia. The 37 cases reported in the literature illustrate the complexity of the pathological implications of these anomalies. We report another case and our diagnostic methodology. We propose lumbosacral arthrodesis which provided complete relief in our patient. This satisfactory outcome has been maintained at one year.

[Comminuted fractures in multiple trauma patients: an analysis of 31 cases]. / Fracture comminutive du calcanéum chez le polytraumatisé. Analyse de 31 cas.

PURPOSE OF THE STUDY: We analyzed calcaneum burst fractures in multiple trauma patients and propose a management scheme. MATERIAL AND METHODS: In a retrospective study, we isolated 23 patients with 31 calcaneum burst fractures. All were stage V in the Duparc classification. We call them "pied de mine" fractures as they resembled those described in military reports. Half of them (16 cases; 54%) were open fractures. All patients suffered multiple injuries and 12 had a psychiatric history. These fractures were associated with spinal fracture in 17 cases (73%) and half had neurologic deficit, limb fracture in 16 (73%), and pelvic fracture in 12 (52%). The most frequent associated foot injuries were a talus fracture in 9 cases (29%) and Chopart displacement in 10 cases (32%). Clinical evaluation used the Maryland foot score, foot print and radiologic evaluation with lateral retrotibial view. RESULTS: Mean follow-up was 35 months. Mean Maryland foot score was 62.7 and 13 cases were pain free. Pain was due to conflict with the lateral malleolus, bony plantar thorns, medial malleolus and subtalar osteoarthritis. Orthopedic shoes were used 11 times. The other patients used sports shoes. Subtalar mobility was most frequently absent (23/29 cases, 2 amputations). Foot print showed 13/16 flat feet; 6 thorns were indirectly visible. Two patients had retraction toes and were initially treated by external fixation. Radiologic evaluation showed 23/29 complete subtalar arthrodeses, 23/29 migration of the great tuberosity, often(17/23 cases) associated with varus angulation. Eleven patients needed subsequent surgery: 5 for arthrodeses and 6 for resection of bony thorns. Rate of complication was high, especially for open fractures: 2 infections for 15 closed fractures, and 8 infections (50%) for 16 open fractures with 2 cases of chronic osteitis. Secondary amputation was required in 2/31 cases due to sepsis. TREATMENT PROPOSITIONS: For closed calcaneum burst fractures, it is better to wait one week before osteosynthesis. This delay is used to decrease edema with limb elevation and compressive bandaging. Skin tension due to trauma is increased by edema and osteosynthesis gives a high risk of wound disunion. We recommend reduction and Y-plate fixation even for burst fracture. Reduction must lower the tuberosity and correct the varus. After surgery, subtalar spontaneous arthrodesis is usually observed in a good position. Any bony plantar thorn must be resected. For open calcaneum burst fracture, the risk of sepsis is high. First treatment is debridement, stabilization and external fixation with antibiotic therapy. Stabilization should improve vascularization and facilitate internal fixation. The external fixation can be placed on the medial side to free the lateral approach to the calcaneum. Flap repair can be performed after one week when skin tension has subsided and areas of necrosis controlled.

Sagittal alignment in lumbosacral fusion: relations between radiological parameters and pain.

The objective of this study was to conduct a radiological analysis of posture before and after lumbosacral fusion to evaluate the influence of spinal alignment on the occurrence and pattern of post surgical pain. The study included 81 patients, of whom 51 had a history of previous low back surgery. We excluded patients with suspected or confirmed nonunion. In the fusion group, the 27 patients who were pain free after the procedure were compared to the 54 patients with residual pain. Thirty patients had pain only or primarily when they were standing immobile, 18 when they were sitting immobile, and six in both positions. Measurements were done on full-length lateral radiographs of the spine, with the patient standing according to Duval Beaupère criteria. The subgroup with postfusion pain was characterized at baseline by a more vertical sacrum with less sacral tilt (ST) (P < 0.0062) and more pelvic tilt (PT) (P < 0.0160). PT at last follow-up (PT fu) correlated with the presence of postfusion pain (NP: P = 0.0003). In the patients with postfusion pain, PT was almost twice the normal value. ST at last follow-up (ST fu) in the standing position was also correlated with the presence of postfusion pain (P < 0.0001) indicating that the sacrum remained abnormally vertical in the subjects with postfusion pain. Using logistic regression, the only prognostic factor for residual pain at last follow-up was ST fu. Both at pre-operative evaluation and at last follow-up, patients with pain in the standing position or in both the standing and sitting positions were characterized at pre-operative status by a more vertical sacrum with less sacral tilt. The results of this study indicate that, achieving a strong fusion should not be the only goal. Appropriate position of the fused vertebrae is also of paramount importance to minimize muscle work during posture maintenance. The main risk is failing to correct or to causing excessive pelvic retroversion with a vertical sacrum leading to a sagittal alignment that replicates the sitting position. This situation is often accompanied by loss of lumbar lordosis and adversely affects stiff or degenerative hips.

Vertical atlantoaxial dislocation.

An unusual case of vertical atlantoaxial dislocation without medulla oblongata or spinal cord injury is reported. The pathogenic process suggested occipito-axial dislocation. The case was treated surgically with excellent results on mobility and pain.

Anatomic basis of minimal anterior extraperitoneal approach to the lumbar spine.

Anterior lumbar spine approaches may be indicated for fusion in degenerative lumbar spine disorders or to fill discal and bone gaps after fracture reduction. We present an anterior extraperitoneal approach applicable to any discal and vertebral levels from T12 to S1. The anatomic study, based on 25 cadavers, highlights retroperitoneal dissection principles for easy kidney and duodenopancreatic mobilisation and direct left anterior access to the entire lumbar spine. We established a precise description of the lumbar veins and the anastomoses between the left renal vein and hemiazygos system, in order to define different topographic and anatomic factors related to safe and easily reproducible approaches for cage or graft implementation. Independent of the level and previous intraperitoneal surgery, lumbar spine access with this approach safeguards the kidney, ureter, spleen, hypogastric plexus and duodenopancreatic system. Regarding operating time, blood-loss and possibilities for freshening and grafting, this technique seems an effective counterbalance to the difficulties and complex technology of endoscopic approaches. The clinical study includes our first 42 cases in traumatic and degenerative lesions. Avoiding the neurologic or hemorrhagic risk inherent in classical posterior lumbar interbody fusion (PLIF) techniques, it can be considered as a reasonable and valid alternative. This technique could be used in the near future for mini invasive discal prosthesis insertion.

[Practical aspects of knee anatomy]. / Aspects pratiques de l'anatomie du genou.

The anatomy of the knee provides a standardised description of articular surfaces, ligament and tendinous insertions in order to understand the combined action of the femoro-tibial and femoro-patellar compartments, as well as their stabilisation mechanisms. Nevertheless, the isolated vision of the articulation is insufficient; one also needs to study the global action of the limb by integrating the rotation of the whole skeletal body and its positions in the sagittal and frontal plans.