Solitary fibrous tumor of the scalp: a case report

The solitary fibrous tumor is a rare tumor, ubiquitous, mesenchymatous essentially affecting serosal surfaces. The location in the scalp is exceptional. We report a case of tumor in left occipital scalp discovered after recurrence of a tumor initially taken for a lipoma. The motive for consultation was mainly aesthetic. The pathological examination is the main element of diagnosis. The assumption is based on a large lumpectomy and an extended and regular clinical monitoring. The forecast is favourable with a decline of one year. However, relapses may occur in the long-term and there are malignant forms.     

Management of humeral fracture nonunion in severe osteoporosis by a combination of locking plating and intramedullary fibular grafting

Nonunion of the humerus in a severely osteoporotic bone is a likely event especially if the fracture is transverse. The management of such a combination is a challenge. Most of the conventional fixation methods are unlikely to succeed as the bone failure precedes implant failure in osteoporosis. The challenge is further compounded in severe osteoporosis when the cortical thickness is affected more severely. We used a combination of an intramedullary fibula with a locking plate in 5 cases. The results show that it may be a good combination in such situations as the bone strength is augmented and the plate pullout is less likely.     

Hip Arthroscopy Without a Perineal Post: A Safer Technique for Hip Distraction

Pudendal nerve palsy is a reported complication of hip arthroscopy. We report a technique using a deflated taped beanbag rather than a perineal post. The patient is placed in the supine or lateral position on a fracture table. The beanbag is contoured around the patient’s flank and thorax. The distal aspect of the beanbag is placed no further than the iliac crest, and care is taken to avoid compression of the posterior aspect of the axillary region or the posterior humerus. The molded beanbag is deflated, a blanket is positioned over the abdomen and lower thorax, and with the use of 3-in-wide cloth tape, the patient and beanbag are secured to the operative table circumferentially. The superior margin of the deflated beanbag remains firm, preventing compression of the thorax and avoiding compromised ventilation. The arm on the operative side is placed across the chest and secured to avoid obstruction of the operative field. This patient positioning provides sufficient stability for adequate traction and good visualization while minimizing the risk of a pudendal nerve palsy.     

Optimal manpower policies in a dynamic staff-maximizing bureau

The dynamic problem of optimal manpower planning in a public agency is considered. The budget available to the bureau is replenished at a rate proportional to the output. The objective of the bureau manager is to maximize the staff at the terminal time. The model is non-linear in the control, the hiring rate. Cases where a deficit is allowed are also considered. Boundary solutions are investigated for the case of no deficit, and it is shown that the hiring rate is non-differentiable but continuous.     

Arthroscopic-Assisted Lateral Ligamentous Reconstruction in Combined Ankle and Subtalar Instability

We describe an arthroscopic technique by which to reconstruct both the calcaneofibular ligament and anterior talofibular ligament anatomically. The ankle joint is examined through the anteromedial portal and a lateral portal close to the talar insertion of the anterior talofibular ligament. The subtalar joint is examined through the anterolateral portal and the middle portal. Associated intra-articular pathology (e.g., osteochondral defect) is evaluated and addressed. The calcaneofibular ligament is an extracapsular structure that can be examined arthroscopically through the anterolateral portal in the extra-articular plane. The peroneal tendon sheath is stripped with a small periosteal elevator through the middle subtalar portal, and the calcaneal insertion of the calcaneofibular ligament is identified. The plantaris tendon is identified and freed through multiple small wounds at the medial calf, and the tendon is cut proximally and retrieved to its calcaneal insertion. A calcaneal bone tunnel (tunnel 1) is created between the plantaris tendon and the calcaneofibular ligament insertions by use of a 3.5-mm drill bit. The tendon graft is then looped onto a suture, and the suture is passed through the tunnel to the calcaneofibular ligament insertion and retrieved to the middle subtalar portal. Through the anterolateral subtalar portal, the fibular insertion of the calcaneofibular ligament is identified. Another bone tunnel is created from this point to the posterior edge of the fibula (tunnel 2) with a 3.5-mm drill through the middle subtalar portal. The fibular insertion of the anterior talofibular ligament is identified on ankle arthroscopy. Tunnel 3 is created from this point to the exit point of tunnel 2 through the lateral ankle portal. The tendon graft is retrieved to the lateral ankle joints through the second and third tunnels and is pierced through the lateral ankle capsule and course from intracapsular to extracapsular. The tendon graft loop is anchored to the insertion point of the anterior talofibular ligament by a 4.0-mm cancellous screw with a spiked washer. The tendon graft is tensioned by pulling the free end of the tendon graft while tightening the screw. The free end of the tendon graft and the stay stitch are sutured to surrounding soft tissue or anchored with another 4.0-mm cancellous screw and spiked washer. The procedure is then completed, and a short leg cast is applied. The patient is advised to perform non–weight-bearing walking for 6 weeks.     

Arthroscopic implantation of a three dimensional scaffold for autologous chondrocyte transplantation

The arthroscopic M-ACT technique is applicable for defects at the femoral condyle up to 5 cm2. The size of the defect has to be assessed with a specific scaled, percutaneously inserted needle. Then an 8 mm water-stop-cannula is positioned in a suprameniscal portal. The chondrocyte seeded matrix is trimmed to size the defect. The scaffold is introduced in the joint through the cannula and placed into the defect with a blunt arthroscopic grasp instrument to prevent damage of the scaffold. Then a specific drill guide is inserted through an additional anteromedial portal to place it on the scaffold in a perpendicular angle. The position of the drill guide should not be changed during the next two steps. It may be helpful to hold the matrix in place with a probe inserted through the cannula. A 1.5 mm K-wire is drilled at least 16 mm into the subchondral bone. Then the biodegradable pin (length 16 mm) is placed in the drill guide and carefully hammered into the subchondral bone. The joint is flexed so that the drill guide can be placed on the posterior end of the scaffold. Another hole is drilled with the K-wire and a second pin is inserted. Finally the stability of the matrix is tested with a probe and the joint is mobilized.     

A rare case of Monteggia's lesion in children

The authors present a rare case of a Monteggia lesion in a child. The fracture of the proximal ulnar metaphysis is associated with a dislocation of the radial head. The outcome is good after closed reduction and six weeks cast. Two years later, the function is normal.     

胰腺实性假乳头状瘤的临床病理研究进展

胰腺实性假乳头状肿瘤是一种少见的低度恶性的胰腺实体肿瘤,好发于年轻女性,临床表现无特异性,而病理学特征明显,肿瘤呈囊实性结构,外被纤维包膜,典型表现为肿瘤细胞围绕纤维血管复层排列而形成假乳头状突起,少数肿瘤可出现侵袭性表现.肿瘤细胞表现出广泛的免疫标记表达.其发病机制与Wnt信号通路异常相关,β-catenin、P120-catenin、结肠腺瘤性息肉病基因APC、细胞周期素依赖的激酶抑制物p21和p27在其中发挥重要作用.     

Optimal operation of solar heat storage with off-peak energy price incentive

The problem of minimum cost control of a solar-assisted heat pump/heat storage system is considered. The system is configured to have separate storage for collected solar heat and high-temperature heat, so that night-time (‘off-peak’) operation of the heat pump is possible. The problem of finding the optimal operating strategy when electrical energy is priced at a discount during off-peak hours is considered. The solution of the periodic optimization problem is obtained through the use of state increment dynamic programming, simplified through the use of state feedback linearization/decoupling and augmented with a label-tracing procedure to identify the periodic but unknown initial/terminal state. The algorithm is applied for a typical case study. The results lead to several observations concerning economical operating strategies.     

Endoscopic-Assisted Achilles Tendon Repair With Plantaris Tendon Augmentation

Six portals are made at the sides of the Achilles tendon. The plantaris tendon is harvested and retrieved to the distal-medial portal. The investing fascia of the Achilles tendon is released at the medial border of the tendon. The suture is passed through the tendon end through the medial portal and exits at the tendon surface and then the fascia and skin. The suture is retrieved at the tendon surface through the medial portal. The loops of the suture are retrieved through the proximal-medial, proximal-lateral, and lateral portals, and a loop of suture is then formed at the surface of the tendon and beyond the boundary of the tendon. The suture is passed through the tendon again in a deep-to-superficial direction within the loop and is retrieved through the proximal-medial portal. The suture is tensioned, and a locking stitch is formed. The loops of the suture are retrieved through the medial, lateral, and proximal-lateral portals. The suture is then passed through the tendon in a deep-to-superficial direction and is retrieved again through the proximal-medial portal, and the second locking stitch is formed. This is repeated 3 to 4 times over the medial side of the proximal tendon through the proximal-medial portal, and the suture is then passed to the proximal-lateral portal at the surface of the tendon. Locking stitches are then applied to the lateral side of the tendon. The same procedure is then repeated over the distal tendon with another suture. The tendon ends are approximated with the pair of sutures tied through the medial and lateral portals. The plantaris tendon is passed through the Achilles tendon with a pointed tendon passer through the proximal and distal portals. The plantaris tendon is then looped around the Achilles tendon and sutured to it.     

Unloading of congestion in deterministic queueing networks

The purpose of this paper is to find a control procedure which would efficiently unload the congestion in a queueing network. The congestion phenomenon is described by a dynamic deterministic model. The total waiting time of all entities in the overloaded region is assumed to be a performance index. The Pontryagin maximum principle is applied to show that for the optimal flow pattern cycles cannot exist and all routes leading from the given node to the outside of the overloaded region have to have the same length. These two properties are the basis for a construction of the algorithm. A topological optimization algorithm is used, since the solution must be a tree. The existence and uniqueness of the optimal solution are investigated.     

Surgical treatment of ureteral stenosis after kidney transplantation

Ureteral stenosis is the most frequent complication after kidney transplantation. The diagnosis is based on an elevated creatinine level and a dilatation of the urinary cavity. The first step of the management is a urinary diversion with endo-ureteral prosthesis or a nephrostomy placement. The surgical gold standard is the pyelo-ureterostomy. This is a safe and efficient technique in the treatment of this complication. We describe the different surgical alternatives and the endo-urologic management of the stenosis.     

Variational method for the distributed control of a vibrating beam

The problem of damping out the oscillations of a simply supported beam subject to viscous damping is solved analytically by employing a maximum principle. The basic control problem is to minimize the deflection and the velocity of displacements in a given period of time with the minimum possible expenditure of force. The multiobjective problem is scalarized by using a linear combination of the criteria. This problem is also solved by two heuristic approaches: a direct method and an integral equation approach.     

Normal bone physiology,remodelling and its hormonal regulation

Bone is a complex tissue, which has a number of mechanical and physiological functions. The maintenance and repair of bone is ensured by a constant cycle of turnover and remodelling. The control of this process is equally complex and is regulated by both mechanical and biological controls.     

Restricted structure control of multiple model systems with Series 2 DOF tracking and feedforward action

The solution of a scalar optimal control problem is discussed where the feedback, series tracking and feedforward controllers are chosen to have a very simple. Each controller term may be chosen to be of reduced order, lead/lag, or PID forms, and the controller is required to minimize an LQG cost‐index. The optimization is based upon a cost‐function which also allows separate costing of the terms due to the feedback, tracking and feedforward controllers. The system model can be uncertain and can be represented by a set of models over which the optimization is performed. This provides a form of robust optimal control that might even be applied to non‐linear systems that can be approximated by a set of linearized models. The theoretical problem considered is to obtain the causal, stabilizing, feedback, series‐tracking and feedforward controllers, of a prespecified form, that minimize an LQG criterion over the set of possible linear plant models. The underlying practical problem of importance is to obtain a simple method of tuning low‐order controllers, given only an approximate model of the process. The results are illustrated in a power generation control problem for a system represented by 12 different linearized plant models. The single feedback controller that is obtained has a simple form and stabilizes the full set of models. Copyright © 2001 John Wiley & Sons, Ltd.     

Management of nasolabial clefts: the issue in Dakar

The management of patients with a cleft lip in developing countries is often the prerogative of humanitarian missions from developed countries. The goal of our work is to conduct a first epidemiological, clinical and therapeutic assessment of the management of cleft lips by a local team and to evidence the difficulties faced by us in our working conditions. In a retrospective study covering a period of about five years (January 2004 to March 2009), 205 cases of nasolabial clefts are assembled. The mean age at the time of the first visit is 17 months. A slight female predominance is observed. The majority of patients are from the capital city. A close relative with a cleft is found in 6.8% of them. In 44.9% of cases, it is a simple cleft lip. A cleft palate is associated in 47.8% of cases. Associated malformations are observed in 10.5% of cases. We operated on 110 patients. The mean age at the first surgery is two years. Millard's technique is our technique of choice. No operative mortality is observed. In 17.4% of cases, operative morbidity occurred in the form of suppuration with partial or complete early suture release. The esthetic result is satisfactory in 67.7% of cases. This management could be improved by creating a multidisciplinary team including--in addition to surgeons--dentists, speech-language pathologists, psychologists, etc.     

Isolated primary osteoma cutis of the head: Case report

Osteoma cutis is a rare disease in which there is formation of bony tissue in the skin that causes deformities. The etiology remains unknown and its treatment is controversial. A rare case of primary osteoma cutis in the face and scalp, which was not associated with any syndrome, is described. The patient was treated with surgery and topical retinoic acid. The retinoic acid treatment resulted in an improvement of the frontal area, and stabilized the disease over a two-year follow-up period. Surgical resection was a simple treatment with a quick recovery, minimal scarring and no local recurrence. The patient was followed for two years and presented a satisfactory result.The treatment of osteoma cutis is quite variable, and surgery is the most frequently reported treatment. However, a combination of clinical and surgical treatments seems to be an efficient way to manage these patients.     

A microfluidic device for continuous white blood cell separation and lysis from whole blood

A microfluidic device, which is composed of a blood inlet, a cell lysis solution inlet, a bifurcation outlet containing six microchannels, and a white blood cell (WBC)-lysed solution outlet, is proposed in this study to separate WBCs from whole blood and lyse the WBCs in a continuous and near real-time fashion. The geometry of the microfluidic device is determined based on the bifurcation law and a cell crossover method. The microflow patterns of blood cells in the microfluidic channels are simulated by computational fluid dynamics. The simulation results agree with the experiment results by considering the reduction of blood viscosity in the microfluidic channels. The performance of the microfluidic device is evaluated by investigating the WBC recovery efficiency and the ratio of spectrophotometric absorbance of the blood sample at 260 to that at 280nm. The WBC recovery efficiency at the main channel outlet is 97.2%. The measured spectrophotometric absorbance ratio of 1.82 indicates that the separated WBCs are completely lysed, leaving only pure DNA in the WBC-lysed solution. The continuous cell separation and lysis is completed within only 0.5s. Therefore, it is concluded that the proposed microfluidic device is promising for separating WBCs from whole blood without any pretreatment and lysing the WBCs in a continuous and near real-time fashion. The proposed microfluidic device may be applicable to a lab-on-a-chip for blood analysis.     

A method of hypospadias repair

Summary The treatment of hypospadias requires the release of chordee and the reconstruction of a new urethra to provide for a satisfactory sexual function and normal micturition. A technique is described in two stages. In the first stage a large dorsal apron flap of prepuce skin is developed by a pericoronal incision. The chordee is released well beyond the urethral opening. A button-hole incision allows the prepuce flap to be reflected to the ventral surface. The distal part of this flap is formed into a skinlined tube with raw surface outward and pulled through a transglandular tunnel incision to the tip of the glans while rotating it 180 degrees. The ventral surface is closed. After three to six months, the penis presenting with a subglandular opening of the tube and the proximal hypospadiac urethra, the final reconstruction is undertaken. The excess ventrally shifted skin from the first stage between both orifices is incised by means of two parallel incisions and tubed to form one continuous urethral skin tube. A multi-layer closure burying the tube completes the procedure. The technique has given very encouraging results.     

Splenic pseudocysts. Apropos of a case

The authors report a case of pseudocyst of the spleen. This is a rare entity which is part of nosological type of nonparasitic splenic cysts. It has most often a post-traumatic origin. The diagnosis is evoked in front of a mass of the left hypochondrium and has to be confirmed by further examinations, in particular by sonography and scanner. A microscopic examination of the surgical specimen is the only way to establish the diagnosis of a pseudocyst. The histological characteristic of pseudocyst is absence of epithelium. The splenic pseudocysts require a surgical treatment. In most cases, a splenectomy is performed. A the moment, cyst resection and partial splenectomies are performed by a few authors. This is the type of technique that we prefer especially when the patient is young.