Is a Titanium Implant for Total Knee Arthroplasty Better? A Randomized Controlled Study

BackgroundLighter weight and lower modulus are potential advantages of titanium (Ti) implants over cobalt chrome (CoCr) implants in total knee arthroplasty (TKA). This study was conducted to determine whether Ti implants in TKA resulted in better clinical outcomes and radiologic results.MethodsOne hundred and eight patients (216 knees) with knee arthritis warranting bilateral primary TKA were randomly allocated to undergo Ti rotating-platform TKA in one knee and CoCr rotating-platform TKA in the contralateral knee. The mean follow-up period was 5.3 years (range, 1-7 years). The weight of Ti implants was one-third lighter than that of CoCr implants (133.9 g vs 390.1 g, P < .01). Clinical outcomes were evaluated using clinical scores, patient preferences (lightness, comfort, naturalness, and satisfaction), gait analysis (kinetic and kinematic data), range of motion, and degree of pain. Radiologic results were evaluated based on the radiolucent line (RLL), degree of medial tibial bone loss, and loosening as seen on X-ray.ResultsNo significant differences were observed in clinical scores or patient preference. Regarding implant weight, approximately 70% of patients did not perceive the Ti implant as lighter. No significant differences were observed in gait analysis, range of motion, or degree of pain. The RLL was seen in 9% of the Ti implant group and 19% of the CoCr implant group.ConclusionThe lighter Ti implant did not show any clinical benefit over CoCr implants. The lightness of the Ti implant is not sufficient to matter or be noticeable. However, the Ti implant showed lower rate of RLL than the CoCr implant.Level of Evidencelevel I, randomized controlled trial.     

Cellular neurothekeoma with possible neuroendocrine differentiation.

We report a case of cellular neurothekeoma showing unusual immunohistochemical findings and occurring on the left upper arm of a healthy 48-year-old woman. She presented with a 1 cm, red, asymptomatic, dermal nodule of 1 year duration. A biopsy showed dermal proliferation of plexiform fascicles of spindle-shaped or polygonal cells with plentiful eosinophilic cytoplasms. The immunohistochemical profile included negative stains for S-100, CD34, factor XIIIa, CD68, HMB45, cytokeratins, and EMA, strongly positive stains for neuron specific enolase (NSE), synaptophysin, and chromogranin A, and focally positive ones for NKI/C3 and alpha-smooth muscle actin. Ultrastructural analysis showed undifferentiated mesenchymal cells with cytoplasmic projections and abundant RER. Although we couldn't find any confirmative cell type in this cellular tumor, we believe that cellular neurothekeoma is predominantly composed of undifferentiated cells that can exhibit features of neuroendocrine cells in addition to fibroblastic or myofibroblastic ones, suggesting a divergent cell origin.     

The role of sebaceous gland activity and scalp microfloral metabolism in the etiology of seborrheic dermatitis and dandruff

Most common scalp flaking disorders show a strong correlation with sebaceous gland (SG) activity. Early SG activity in the neonate results in microfloral colonization and cradle cap. After maternal hormonal control subsides, there is little SG activity until puberty, when the SG turns on under sex hormone control. When the SG activity increases, the present but low Malassezia population has a new food source and proliferates, resulting in the scalp itching and flaking common to greater than 50% of adults. Dry scalp flaking, dandruff, and seborrheic dermatitis are chronic scalp manifestations of similar etiology differing only in severity. The common etiology is a convergence of three factors: (1) SG secretions, (2) microfloral metabolism, and (3) individual susceptibility. Dandruff and seborrheic dermatitis (D/SD) are more than superficial stratum corneum disorders, including alteration of the epidermis with hyperproliferation, excess lipids, interdigitation of the corneal envelope, and parakeratosis. The pathogenic role of Malassezia in D/SD has recently been elucidated, and is focused on their lipid metabolism. Malassezia restricta and M. globosa require lipids. They degrade sebum, free fatty acids from triglycerides, consume specific saturated fatty acids, and leave behind the unsaturates. Penetration of the modified sebaceous secretions results in inflammation, irritation, and scalp flaking.     

Síndrome malformaciones capilares-malformaciones arteriovenosas: presentación de 2 casos,claves diagnósticas y manejo

Capillary malformation-arteriovenous malformation syndrome is a rare type of vascular malformation first described in 2003. It is an autosomal dominant inherited disorder that has been reported in association with heterozygous mutations in the RASA1 gene, which encodes the protein RASp21. The clinical picture is characterized by multiple small capillary malformations which are associated with either arteriovenous malformations or arteriovenous fistulas in both the affected individual and other members of their family. We describe 2 new familial cases of this syndrome that were clinically and genetically diagnosed and studied in our hospital.     

Pigmentation in Koreans: study of the differences from caucasians in age, gender and seasonal variations

BACKGROUND: Human skin colour shows variations throughout life, and many extrinsic and intrinsic factors influence melanogenesis. Facultative pigmentation of sun-exposed skin has been suggested to reflect cumulative lifetime ultraviolet (UV) exposure in caucasians. However, pigmentary changes due to various regulatory factors may be different in dark-skinned peoples. OBJECTIVES: To observe the variations in skin colour due to ageing, gender differences and seasonal changes in Koreans with skin type IV or V. METHODS: Skin pigmentation was measured at five body sites (buttock, glabella, the V of the neck area, inner arm and dorsal forearm) using skin reflectance spectroscopy in 497 subjects (age range 0-87 years) in winter and 311 subjects (age range 0-84 years) in summer. Among these subjects, 110 were assessed in both seasons. Three independent measurements at each site were done and the average value was used as the pigmentation level. RESULTS: Constitutive pigmentation of the buttock was highest in the first decade of life. It then decreased during the second decade and this decreased level was maintained after the third decade. In contrast to caucasians, facultative pigmentation and sun exposure index did not increase with ageing. Gender differences were significant at all body sites after the first decade. Seasonal changes were apparent in dorsal forearm pigmentation. Little difference was seen in forehead pigmentation between summer and winter. CONCLUSIONS: Basal melanogenic regulation might not be different between Asians and caucasians. However, the sun exposure index may not represent lifelong cumulative UV exposure in Koreans. Age-, gender- and season-related characteristics of skin pigmentation in Koreans imply that genetically determined basal skin colour plays an important part in characterizing later responsiveness to UV radiation and sex hormones. Understanding differences between races will be helpful in studying the regulatory mechanisms of melanogenesis.     

Laser photoirradiation of the canine ureteral orifice: comparison between contact and noncontact techniques

We studied the long-term effects of Nd:YAG laser photoirradiation in 17 canine ureteral orifices, comparing results of the contact and noncontact (free-fiber) techniques. The noncontact technique damaged four of eight ureters, causing ureteral obstruction with significant hydronephrosis in three and reflux in one. The amount of energy used correlated with the subsequent appearance of ureteral obstruction; obstruction developed in both cases when 3,000 and 3,300 joules were used but in only one of five cases when less than 2,300 joules were used. In contrast, the contact technique, using 350-800 joules, caused no hydronephrosis and only one case of reflux. Since these animal studies clearly document that the Nd:YAG laser may significantly damage the ureter, particularly when the noncontact technique is used, we recommend that the surgeon consider the contact technique to reduce the risk of ureteral damage and use the smallest amount of energy required for adequate tumor eradication when treating tumors in or near the ureteral orifice.     

Use of robotics in the realization of external perosseous osteosynthesis

The authors expound the principles of making up of the algorithm (program) for diagnosis and implementation of the optimal variations of rod insertion in various types of fractures of the extremities and the method of adaptation of the program to a specific fracture according to its biomechanical characteristics. The succession of the realization of the program of insertion of the rods, reposition of the fragments and application of the apparatus with the aid of the robot are described.