Integrated fixed-film activated sludge ANITA™Mox process--a new perspective for advanced nitrogen removal.

ANITA™Mox is a Veolia process using moving-bed biofilm reactor (MBBR) technology tested and validated in full-scale for energy- and cost-effective autotrophic N-removal from sidestream effluent using anammox (ANaerobic AMMonium OXidation) bacteria. In order to increase the ANITA™Mox process performances under different operating conditions (e.g. mainstream and sidestream application), substrate transport and accessibility inside the biofilm must be enhanced. In this work, (i) two laboratory scale biofilm ANITA™Mox reactors were operated using different configurations (IFAS - integrated fixed-film activated sludge - and MBBR) and (ii) the distribution of the anammox (AnAOB) and ammonia-oxidizing bacteria (AOB) in the suspended sludge and the biofilm was characterized using molecular tools (qPCR). This study showed that in IFAS configuration, the ANITA™Mox process achieved very high N-removal rate (up to 8 gN/m².d), which was three to four times higher than that achieved in the pure MBBR mode. The high concentration of suspended solids (mixed liquor suspended solids (MLSS)) in the bulk obtained within the IFAS mode induces a very efficient bacterial distribution between the AOB and AnAOB population. AnAOB activity mainly occurs in the biofilm (96% of total AnAOB in the reactor), whereas nitritation by AOB mostly takes place in the suspended phase (93% of total AOB). This spatial distribution observed in the IFAS reactor results from a natural selection due to more easily substrate accessibility for AOB in the bulk (NH4(+), O2) creating higher nitrite concentration in the bulk liquid compare to pure MBBR mode. The efficient control of MLSS level in the IFAS reactor is a key parameter to enhance the nitrite production by AOB and increase the substrate availability in the AnAOB-enriched biofilm leading to higher N-removal rate. These promising results obtained at laboratory scale have been further confirmed in on-going full-scale IFAS ANITA™Mox trials opening new roads for the widespread application of a very compact and robust ANITA™Mox process for sidestream but also mainstream cost-effective N-removal.

Artificial intelligence solution to accelerate the acquisition of MRI images: Impact on the therapeutic care in oncology in radiology and radiotherapy departments.

PURPOSE: MRI is essential in the management of brain tumours. However, long waiting times reduce patient accessibility. Reducing acquisition time could improve access but at the cost of spatial resolution and diagnostic quality. A commercially available artificial intelligence (AI) solution, SubtleMR™, can increase the resolution of acquired images. The objective of this prospective study was to evaluate the impact of this algorithm that halves the acquisition time on the detectability of brain lesions in radiology and radiotherapy. MATERIAL AND METHODS: The T1/T2 MRI of 33 patients with brain metastases or meningiomas were analysed. Images acquired quickly have a matrix divided by two which halves the acquisition time. The visual quality and lesion detectability of the AI images were evaluated by radiologists and radiation oncologist as well as pixel intensity and lesions size. RESULTS: The subjective quality of the image is lower for the AI images compared to the reference images. However, the analysis of lesion detectability shows a specificity of 1 and a sensitivity of 0.92 and 0.77 for radiology and radiotherapy respectively. Undetected lesions on the IA image are lesions with a diameter less than 4mm and statistically low average gadolinium-enhancement contrast. CONCLUSION: It is possible to reduce MRI acquisition times by half using the commercial algorithm to restore the characteristics of the image and obtain good specificity and sensitivity for lesions with a diameter greater than 4mm.

Experience from start-ups of the first ANITA Mox plants.

ANITA™ Mox is a new one-stage deammonification Moving-Bed Biofilm Reactor (MBBR) developed for partial nitrification to nitrite and autotrophic N-removal from N-rich effluents. This deammonification process offers many advantages such as dramatically reduced oxygen requirements, no chemical oxygen demand requirement, lower sludge production, no pre-treatment or requirement of chemicals and thereby being an energy and cost efficient nitrogen removal process. An innovative seeding strategy, the 'BioFarm concept', has been developed in order to decrease the start-up time of new ANITA Mox installations. New ANITA Mox installations are started with typically 3-15% of the added carriers being from the 'BioFarm', with already established anammox biofilm, the rest being new carriers. The first ANITA Mox plant, started up in 2010 at Sjölunda wastewater treatment plant (WWTP) in Malmö, Sweden, proved this seeding concept, reaching an ammonium removal rate of 1.2 kgN/m³ d and approximately 90% ammonia removal within 4 months from start-up. This first ANITA Mox plant is also the BioFarm used for forthcoming installations. Typical features of this first installation were low energy consumption, 1.5 kW/NH4-N-removed, low N2O emissions, <1% of the reduced nitrogen and a very stable and robust process towards variations in loads and process conditions. The second ANITA Mox plant, started up at Sundets WWTP in Växjö, Sweden, reached full capacity with more than 90% ammonia removal within 2 months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period.

Modelling and simulation revealing mechanisms likely responsible for achieving the nitrite pathway through aeration control.

Nitrogen removal via nitrite has recently gained a lot of interest because it results in significant savings in both aeration costs and COD (chemical oxygen demand) requirements for denitrification, when compared to the conventional biological nitrogen removal via nitrate. The effectiveness of two different control strategies to achieve the nitrite pathway in systems with sludge retention has been experimentally demonstrated: (i) control of aerobic phase length, with which aeration is terminated as soon as ammonia is completely oxidised; (ii) operation at low DO setpoints in the aerobic phase. These strategies have been extensively studied in nitrifying reactors and are currently applied in real systems achieving biological carbon, nitrogen and phosphorus removal. In this work, we aim to demonstrate, through modelling and simulation, that the competition between nitrite reducers and nitrite oxidisers for nitrite, rather than kinetic selection plays a major role in NOB washout. Moreover, the results show that the occurrence of simultaneous nitrification and denitrification under "aerobic" conditions is very helpful for the nitrite pathway obtainment and for a more efficient COD utilisation.

Cartilage oligomeric matrix protein expression in systemic sclerosis reveals heterogeneity of dermal fibroblast responses to transforming growth factor beta.

OBJECTIVE: Cartilage oligomeric matrix protein (COMP) accumulates in systemic sclerosis (SSc) skin and is upregulated by transforming growth factor (TGF)beta. To further characterise the response to TGFbeta in SSc, we investigated TGFbeta1 and COMP expression and myofibroblast staining in SSc skin. METHODS: Skin biopsies from patients with diffuse cutaneous SSc (dSSc), limited cutaneous SSc (lSSc) and healthy controls were evaluated for COMP mRNA expression using real-time PCR. COMP, alpha-smooth muscle actin (SMA) and TGFbeta were assessed in skin sections and in cultured fibroblasts by immunohistochemistry. Clinical disease status was assessed by the modified Rodnan skin score (mRSS). RESULTS: Myofibroblasts expressing SMA and COMP were found coexpressed in many cells in dSSc dermis, but each also stained distinct cells in the dermis. Cultured SSc dermal fibroblasts also showed heterogeneity for COMP and SMA expression, with cells expressing SMA, COMP, both or neither. TGFbeta treatment increased COMP and SMA-expressing cells. COMP mRNA expression in lesional skin from patients with dSSc correlated with the mRSS and TGFbeta1 staining. CONCLUSION: These findings suggest that TGFbeta upregulation of COMP and/or SMA expression in subpopulations of fibroblasts contributes to different pathways of fibrosis and that multiple TGFbeta regulated genes may serve as biomarkers for the degree of SSc skin involvement.

Development and numerical/experimental characterization of a lab-scale flat flame reactor allowing the analysis of pulverized solid fuel devolatilization and oxidation at high heating rates.

This paper deals with the thorough characterization of a new experimental test bench designed to study the devolatilization and oxidation of pulverized fuel particles in a wide range of operating conditions. This lab-scale facility is composed of a fuel feeding system, the functioning of which has been optimized by computational fluid dynamics. It allows delivering a constant and time-independent mass flow rate of fuel particles which are pneumatically transported to the central injector of a hybrid McKenna burner using a carrier gas stream that can be inert or oxidant depending on the targeted application. A premixed propane/air laminar flat flame stabilized on the porous part of the burner is used to generate the hot gases insuring the heating of the central coal/carrier-gas jet with a thermal gradient similar to those found in industrial combustors (>10(5) K/s). In the present work, results issued from numerical simulations performed a priori to characterize the velocity and temperature fields in the reaction chamber have been analyzed and confronted with experimental measurements carried out by coupling particle image velocimetry, thermocouple and two-color pyrometry measurements so as to validate the order of magnitude of the heating rate delivered by such a new test bench. Finally, the main features of the flat flame reactor we developed have been discussed with respect to those of another laboratory-scale system designed to study coal devolatilization at a high heating rate.

Specific expression of matrix metalloproteinases 1, 3, 9 and 13 associated with invasiveness of breast cancer cells in vitro.

Several matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) were studied in highly invasive (MDA-MB-231) and slightly invasive (MCF-7, T47D, BT-20) breast cancer cell lines. Investigations were carried out at the protein level and/or at the mRNA level, either in cells cultured as monolayers on plastic, or in cells seeded on a thin layer of Matrigel basement membrane matrix. Analysis of MMP expression by RT-PCR showed expression of MMP-1. MMP-3, and MMP-13 in highly invasive MDA-MB-231 cells, but not in slightly invasive cell lines. The extracellular secretion of MMP-1 and MMP-3 by MDA-MB 231 cells could be also shown by ELISA. TIMP-1 and TIMP-2 mRNAs were found in all cell lines, however, the extracellular secretion of both TIMPs was much higher in MDA-MB-231 cells than in the other cell lines. When the cells were cultured on Matrigel matrix, MMP-9 expression was induced in MDA-MB-231 cells only, as assessed by RT-PCR and zymography experiments. The invasive potential of MDA-MB-231 cells evaluated in vitro through Matrigel was significantly inhibited by the MMP inhibitor BB-2516, by 25% and 50% at the concentrations of 2 x 10(-6) M and 10(-5) M, respectively. In conclusion, our data show that highly invasive MDA-MB-231 cells but not slightly invasive T47D, MCF-7 and BT-20 cells express MMP-1, MMP-3, MMP-9 and MMP-13. MMP-9 which is specifically up-regulated by cell contact to Matrigel, may play a key role in the invasiveness of MDA-MB-231 cells through basement membranes.

Fracture of the radial head with associated elbow dislocation: results of treatment using a floating radial head prosthesis.

OBJECTIVES: To assess elbow function, complications, and problems of radial head fractures associated with elbow dislocation receiving surgical treatment with a floating prosthesis. DESIGN: Prospective clinical study. SETTING: University Hospital, Orthopaedic Department, Sart Tilman, Liège, Belgium. PATIENTS: Eleven consecutive adult patients were treated with a floating prosthesis for acute radial head fractures associated with elbow dislocation from January 1994 to September 1996. INTERVENTION: The floating radial head prosthesis (Tornier SA, Saint-Ismier, France) was used in all our patients. The implant is in two parts: a radial head made of high-density polyethylene enclosed in a cobalt-chrome cup, which articulates in a semiconstrained manner with the spherical end of a cemented intramedullary stem. The implants were inserted within the first week following the injury (range 2 to 7 days). Three cases also required internal fixation of the coronoid process of the ulna; in one case plate fixation of an olecranon fracture was also performed. MAIN OUTCOME MEASUREMENTS: Patients were assessed by physical examination, a functional rating index (Morrey et al.), and radiographs. The parameters evaluated were motion, stability, pain, and grip strength. Potential complications such as infection, prosthetic failure, or dislocation were investigated. RESULTS: The minimum follow-up time was two years (mean 32 months, range 24 to 56 months). Four patients were considered to have excellent results, four patients were considered to have good results, two patients had fair results, and one patient had a poor result. There were no cases of infection, prosthetic failure, or dislocation. No patient required prosthetic revision. CONCLUSION: The basic principle of maintaining anatomic and physiologic relationships applies when deciding on treatment for radial head fractures with associated elbow dislocation. The loss of lateral osseous support will render the elbow grossly unstable. We believe that a floating prosthesis may be indicated in Mason Type III radial head fractures associated with elbow dislocation, especially in the presence of associated destabilizing fractures. Well-controlled comparative randomized studies will be needed to delineate the optimal treatment for a given situation.

[Digestive lymphomatous polyposis]. / Polypose lymphomateuse digestive.

We report 7 prospectively followed cases of lymphomatous polyposis of the gastrointestinal tract. They were characterized by multiple polypoid lesions affecting several segments of the gastrointestinal tract always involving the colon and the rectum. An ileocecal mass was present in 4 cases. Regional lymph node involvement was constant. Peripheral lymphadenopathy was frequent (5 cases out of 7), as was other extra-digestive extension to the bone marrow (4 cases out of 7) and cavum (3 cases out of 7). The histopathological aspect was that of a small cleaved cells (working formulation) or centrocytic (Kiel classification) non-Hodgkin's lymphoma. The peculiar morphology and phenotype of the tumoral B-lymphocytes suggest their possible follicle marginal zone origin. Lymphomatous polyposis bore a rapidly fatal prognosis in every case (mean survival 20 months). This study of seven patients together with the 20 well-documented cases of the literature confirms the existence of lymphomatous polyposis as a distinctive clinicopathological entity among gastrointestinal non-Hodgkin's lymphoma.

[The motor structures responsible for venous flow]. / Les structures motrices responsables de l'écoulement veineux.

There are numerous forces which propel the blood within the veins: --At tissue venule level the residual arteriolar pressure especially intervenes. --At peripheral vein level, the dominant forces are those which lower the transmural pressure, either by decreasing intravascular pressure (gravity, aspiration from neighbouring veins), or by increasing the extravascular pressure creating a compression effect by squeezing of the flexible vessel between muscles and a rigid aponeurosis. --At central vein level, the principal role is ensured by the thoraco-abdominal mechanics, whereby contraction of the diaphragm produces compression and aspiration. The right heart intervenes, when required, and directs blood towards the pulmonary circulation. The result of the simultaneous, successive application of these forces, differs depending on the organ. In addition, the flexibility of the vessel varies according to neuro-hormonal control. Finally, the rheological properties of the fluid and the degree of backflow must be taken into account. Thus, one gets a double flow (hydraulic transfer, propagated waves) which varies according to requirements. The energy expenditure due to flow is a function of the characteristics and volume of the liquid displaced. The complexity of such a flow has the advantage of adaptability but the inconvenience of fragility.

A novel wastewater treatment process: simultaneous nitrification, denitrification and phosphorus removal.

Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic enhanced biological phosphorus removal (EBPR) are two processes that can significantly reduce the COD demand for nitrogen and phosphorus removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and phosphorus removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen concentration (DO, 0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification and phosphorus removal. Under anaerobic conditions, COD was taken up and converted to polyhydroxyalkanoates (PHA), accompanied with phosphorus release. In the subsequent aerobic stage, PHA was oxidized and phosphorus was taken up to less than 0.5 mg/L at the end of the cycle. Ammonia was also oxidised during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis found that the final denitrification product was mainly nitrous oxide (N2O) not N2. Further experimental results demonstrated that nitrogen removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms rather than denitrifying polyphosphate-accumulating organisms were responsible for the denitrification activity.

[Prosthetic knee arthroplasty: current status and future perspectives]. / L'arthroplastie prothétique du genou: état actuel et perspectives d'avenir.

Prosthetic replacement of the knee-joint has become an accepted method of treatment for osteo-arthritis and various inflammatory, metabolic or hematologic conditions of the knee-joint. It usually makes use of semi-constrained resurfacing prostheses which belong to several types differing by their degree of constraint and their intrinsic stability which are related to implant geometry and implantation technique. Ancillary instruments have been developed which make it possible, provided the rationale of the operation is well understood, to reproducibly attain the goals of the operation, i.e. limb realignment, ligament balance in flexion and extension, adjustment of joint-line level and correct patellar tracking. Improvement in the clinical outcome of the operation has also resulted from better rehabilitation and postoperative treatment, particularly to prevent local and systemic complications.

[Osteoarthrosis of the knee joint, a predictable consequence of meniscectomy in patients with angular deformity of the knee (author's transl)]. / L'arthrose fémoro-tibiale, conséquence prévisible de la méniscectomie sur genoux désaxés.

The load-bearing function of the menisci is now well established. Meniscectomy increases the load per unit area in the operated femorotibial compartment; this may result into accelerated wear and osteoarthrosis. This is even more likely to occur if meniscectomy is performed on a knee-joint which presents with a mechanical imbalance secondary to angular deformity in the frontal plane. Often, in such cases, the meniscus only displays secondary, degenerative changes, which do not justify meniscectomy. Through a better knowledge of the load-bearing function of the menisci and a more thorough clinical and roentgenological preoperative study in painful knees, undue meniscectomy could be avoided in a number of cases and the frequence of iatrogenic postmeniscectomy osteoarthrosis of the knee-joint could be reduced.

[Treatment of osteoarticular lesions associated with traumatic vascular lesions]. / Traitement des lésions ostéo-articulaires associées á des lésions vasculaires traumatiques.

A critical study is made of the management of fractures associated with major vascular injuries. The pros and cons of surgical and conservative management are analyzed; it is emphasized that internal fixation, although largely used in civilian practice, is by no means necessary for successful vascular repair. The latter must be given prevalence in every instance, and an aggressive approach to the skeletal lesion is justified only in selected cases where it will not jeopardize the results of vascular repair. The therapeutic approach is analyzed step by step: selection of external or internal fixation, chronological sequence of procedures, selection of a mode of internal fixation and of a surgical approach. The different techniques of internal fixation available for upper and lower limb fractures are considered. It is concluded that the method of management of fractures associated with vascular injuries remains controversial and must be selected in every instance by a team discussion taking into account the various parameters related to both skeletal and vascular problems.

[Surgery in the octogenarian (introduction). Results of a national survey]. / Chirurgie de l'octogénaire (introduction). Résultats d'une enquête nationale.

Presentation of the results of a national, multicentric and retrospective study regarding the surgery of the octogenarian. The series counts 7,407 patients accepted for surgery, and which can be divided into 4,581 women (61.8%) and 2,826 men (38.2%) of an average age of 84.4 years old (extremities 80-101 years old). The global mortality of this population of elderly (whether operated on or not) amounts to 16.7%. The postoperative mortality of the 4,177 operated patients is 18.2% with different rates according to the surgical disciplines: 34.7% for surgery of the colon, 23.2% for bone surgery, 22.4% for vascular surgery, 15.3% for biliary surgery, 8.7% for urologic surgery and 5.6% for cardiac surgery.

Diagnosis and treatment of acute ruptures of the Achilles tendon. Current concepts review.

Subcutaneous rupture of the Achilles tendon seems to have become more common in recent years. This results from a combination of more awareness in the medical field and greater participation in physical activities by the general population. The causes of Achilles tendon rupture are multifactorial and still unclear. The diagnosis can be made based on physical examination; special diagnostic studies are rarely necessary. The literature on ruptures of the Achilles tendon and associated treatment has expanded over the past decade. The lack of a universal, consistent protocol for subjective and objective evaluation following treatment of Achilles tendon rupture has prevented any comparison of results. There is still controversy concerning the best treatment. From a literature review, it appears that a satisfactory outcome may be achieved with either nonoperative or operative treatment but surgical repair appears to provide better functional capacity. Lower rerupture rates and slightly improved strength and functional ability may be expected with surgical treatment; however, the rate of minor complications is higher than with nonoperative treatment. Reports in the literature indicate that in active, young, very demanding individuals, surgical repair should be considered, with nonsurgical treatment reserved for elderly or sedentary patients. There is no single, uniformly accepted surgical technique for Achilles tendon repair. Most acute ruptures have been treated successfully with simple end-to-end suture, although various augmentation procedures have been combined with simple suture with satisfactory outcomes. To minimize the complications typically associated with open surgery, percutaneous techniques to repair the ruptured Achilles tendon have been advocated, and the results are reported to be promising, although not without failures and complications. Several recent studies have reported functional benefits of early postoperative tendon mobilization in well-motivated patients, since treatment results are determined not only by the method of repair but also, and perhaps more importantly, by the early postoperative functional rehabilitation.

[Current role of the osteoplastic shelf in the treatment of sequelae of hip dislocation in adults]. / Place actuelle de la butée ostéoplastique dans le traitement des séquelles de la maladie luxante chez l'adulte.

This operation, first described by König at the end of the 19th century, continues to have some indications. This simple operation should be performed with a very precise technique: the new shelf is placed at the rim of the acetabulum on the capsule; the shelf should be solid and well-fitting, making any secondary displacement impossible, even when the patient is walking. The hip should be covered anteriorly and superiorly. The main indication is a dysplastic acetabulum, especially with a vertical roof. The best results are seen after operation on dysplastic hips without osteoarthritis; when osteoarthritis is present, the results are less good. The procedure is generally indicated only in patients younger than 45 years and it is relatively contraindicated in patients over 50 years old. It is very important to discuss the indication for this operation with the patient; it is a prophylactic measure performed on a hip with normal mobility and little pain.

[Radiological study of the migration of prosthetic implants following hip arthroplasty]. / Etude radiologique de la migration des implants prothétiques après arthroplastie de hanche.

Migration of the acetabular and femoral implants after THR is a better index of the stability of the bone-implant interfaces than are clinical or radiological results. Roentgenstereophotogrammetry (RSA) studies 3-D migration of the implants with high accuracy (0.15 to 0.28 mm for linear migrations). RSA presents several drawbacks which restrict its use to prospective studies on small numbers of patients. Simpler methods have therefore been developed to assess 2-D migration on standard films in retrospective studies. The precision of these "simple" methods is limited, due to several factors: the difficulty to define reliable landmarks on femur or pelvis, sometimes even on implants, measurement errors, related to variations in radiographic technique (focal distance, beam centering, patient positioning). Sutherland, Wetherell and Nunn have proposed methods with an accuracy around 2-3 mm. It appears impossible to correct migration measurements for distorsions due to patient positioning; the EBRA method was therefore developed to reject non-comparable films using a comparability algorithm. A precision of 0.20 to 0.32 mm can thus be reached for the study of cup migration. The same pitfalls are encountered in assessment of migration of the femoral implant; a preliminary theoretical study is mandatory for every implant studied. The data presently available show that migration at 2 years is predictive of the long-term evolution of an implant; for the cup, migration of 1 mm or more at 2 years is predictive of late failure, and similar conclusions can be drawn regarding the femoral implant. The 2-D assessment of implant migration using a correct "simple" method provides a mean to evaluate a new implant or an innovative technical modification in a reasonable amount of time, on a limited number of patients.

[Morphology of the tibial tuberosity]. / La morphologie de la tubérosité tibiale.

The influence of anterior projection of the tibial tuberosity in the pathogenesis of anterior knee pain syndromes has been given relatively little attention. This point has been investigated by performing a morphological study of 77 knee-joints with a standard radiological method. The knees fell into two groups: one of them included typical patellar syndromes, the other group included knees presenting with some other conditions, mostly meniscal. A subjective evaluation of the shape of the tuberosity was made and correlated with clinical status. An objective rating was attempted by measuring the anterior projection of the tuberosity, in order to eliminate the influence of skeletal size, it was expressed as a ratio between two values. Subjective evaluation of the shapes of the tuberosities was found unreliable. The individual values for the calculated index of anterior projection were found to be scattered for every morphological type. It appeared difficult to conclude that there is a definite proven relationship between hypoplasia of the tuberosity and overloading of the femoro-patellar joint. Evaluation of the anterior projection of the tuberosity should take into account the position of the tuberosity in the coronal plane.

[Transposition of the tibial tuberosity in recurrent dislocations and painful femoro-patellar syndromes. Study of a continuous series of 140 operated knees]. / La transposition de la tubérosité tibiale dans les luxations récidivantes et les syndromes douloureux fémoro-patellaires. Etude d'une série continue de 140 genoux opérés.

Surgical displacement of the tibial tuberosity has been performed in 140 cases over a 10-year period. Medial displacement with or without ventralization of the tuberosity gave excellent results in all 11 cases presenting with recurrent patellar dislocation. Anterior displacement of the tuberosity using a modified Maquet procedure was performed in 129 knees presenting with femoro-patellar pain (chondromalacia patellae, femoro-patellar osteoarthritis). Indication for surgery was intractable femoropatellar pain. Surgical technique (isolated anterior translocation or anterior and internal translocation of the tuberosity) was selected according to clinical and radiological examination. Results were very good in 50% of cases, good in 30%, poor in 20%. No patient was made worse after the procedure. The complication rate was acceptably low, due to meticulous surgical technique. The overall good results in this series are related to strict selection of patients.