Antibacterial effect of PEO coating with silver on AA7075.

In this work, plasma electrolytic oxidation (PEO) coatings were produced on AA7075 using alkaline solution containing silicates compounds and silver micrometric particles in order to give to the coating an antimicrobial effect. In the optic of circular economy, silver chloride derived from the acid pre-treatment of electronic scraps was used as raw material and successively silver powders were synthesized from silver chloride solution using glucose syrup as reducing agent. The coatings were characterized by scanning electron microscope (SEM), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization test and antimicrobial tests. The results evidenced that the obtained coatings were homogenous and give to the samples higher corrosion resistance than untreated alloy. The silver particles, found both inside and outside of the pores that characterize the PEO layer, produced an efficacious antimicrobial effect both against E. coli and S. aureus.

Sweat rate and fluid turnover in American football players compared with runners in a hot and humid environment.

OBJECTIVES: To determine sweat rate (SwR) and fluid requirements for American footballers practicing in a hot, humid environment compared with cross country runners in the same conditions. METHODS: Fifteen subjects, 10 footballers and five runners, participated. On the 4th and 8th day of preseason two a day practices, SwR during exercise was determined in both morning and afternoon practices/runs from the change in body mass adjusted for fluids consumed and urine produced. Unpaired t tests were used to determine differences between groups. RESULTS: Overall SwR measured in litres/h was higher in the footballers than the cross country runners (2.14 (0.53) v 1.77 (0.4); p<0.01). Total sweat loss in both morning (4.83 (1.2) v 1.56 (0.39) litres) and afternoon (4.8 (1.2) v 1.97 (0.28) litres) practices/runs, and daily sweat losses (9.4 (2.2) v 3.53 (0.54) litres) were higher in the footballers (p<0.0001). The footballers consumed larger volumes of fluid during both morning and afternoon practices/runs (23.9 (8.9) v 5.5 (3.1) ml/min and 23.5 (7.3) v 13.6 (5.6) ml/min; p<0.01). For complete hydration, the necessary daily fluid consumption calculated as 130% of daily sweat loss in the footballers was 12.2 (2.9) litres compared with 4.6 (0.7) litres in the runners (p<0.0001). Calculated 24 hour fluid requirements in the footballers ranged from 8.8 to 19 litres. CONCLUSIONS: The American footballers had a high SwR with large total daily sweat losses. Consuming large volumes of hypotonic fluid may promote sodium dilution. Recommendations for fluid and electrolyte replacement must be carefully considered and monitored in footballers to promote safe hydration and avoid hyponatraemia.

New approaches to the chemical synthesis of bioactive oligosaccharides.

The past year has seen some major advances in the area of carbohydrate synthesis using chemical methods. Progress in all areas of synthetic methodology, including new protecting groups and coupling methods, has been reported. A number of complex carbohydrate structures have been prepared using known, as well as new, methods. The goal to allow nonspecialists access to defined carbohydrate structures for biochemical, biophysical and biological studies has drawn closer by the introduction of two approaches towards synthesis automation. A one-pot glycosylation strategy utilized computer-assisted synthesis planning and the first solid-phase automated synthesizer was introduced very recently.

Ethics in sports medicine.

Sports medicine physicians are not exempt from the ethical challenges of medical practice merely because their patients are robust and healthy. In fact, precisely because the patients with sports injuries are so healthy the moral issues remain subtle. Many ethical issues in sports medicine come about because the traditional relationship between doctor and patient is altered or absent. In the current review, several routine topics in biomedical ethics, including doctor and patient confidentiality, informed consent, the care of minors, medical advertising and use of innovative treatments, will be studied from the sports medicine perspective. Hypothetical case histories will be presented, along with an analysis of the underlying ethical issues. The goal of this analysis is not to offer answers to these moral questions, but to increase awareness and promote contemplation of the correct course of action.

A new procedure for the preparation of beta-keto-delta-lactones from sugars and their transformation into glycosyl acceptors in disaccharides synthesis

[reaction: see text] Glycals are effective starting materials for the synthesis of enantiopure beta-ketone-delta-lactones. They are easily transformed, through a two-step, one-pot reaction, into the corresponding alpha,alpha'-dioxothiones which in turn can be quantitatively trapped with dienophiles in inverse electron-demand [4 + 2] cycloadditions. The reaction of dioxothione 8b with endo and exo glucals allowed the elaboration of a new protocol to prepare 2-thio- or 2-deoxydisaccharides stereoselectively.

Arthroscopic treatment of patellar clunk.

Excellent results have been reported with posterior stabilized total knee arthroplasty. A common complication relating to patellofemoral articulation is patellar clunk syndrome. Patellar clunk syndrome occurs when a fibrous nodule develops just proximal to the patellar button. At approximately 30 degrees to 45 degrees from full extension, the nodule catches the anterior flange of the femoral prosthesis, resulting in the clunk and a painful range of motion. The present study examines the use of arthroscopic debridement for this disorder. Thirty consecutive patients (32 knees) with the diagnosis of patellar clunk syndrome were evaluated at 1 year after arthroscopic debridement. All patients were evaluated clinically and radiographically according to the Knee Society score. In addition, patients were questioned specifically regarding anterior knee pain and patellofemoral symptoms. Radiographs were evaluated further regarding patella and component position. Patients were diagnosed with patellar clunk at an average of 12 months after their latest knee arthroplasty, with a range of 3 to 47 months. All patients complained of anterior knee pain and the clunk. All patients had a hypertrophic nodule at the junction of the proximal pole of the patella and quadriceps tendon and underwent arthroscopic debridement through a superolateral portal. All patients were free of patellar clunk postoperatively; one patient reported persistent anterior knee pain. Knee Society scores increased from an average of 64 points preoperative to 93 points postoperative. Radiographs showed patella alta in eight knees, patella baja in two. Four femoral components were in 5 degrees flexion. The present study represents the largest collection of data regarding patellar clunk syndrome. The data appear to support arthroscopic debridement as a successful treatment of patellar clunk syndrome.

Percutaneous and arthroscopic screw fixation of scaphoid fractures in the athlete.

The authors prefer to treat nondisplaced acute scaphoid fractures in the athlete on an individualized basis. Percutaneous or arthroscopic-assisted fixation are valuable techniques to employ when prolonged immobilization is a concern. Return to athletic competition has been rapid using these methods. Morbidity has been minimal, and there have been no nonunions to date at the authors' institution.

Lateral ankle sprains: a comprehensive review: part 1: etiology, pathoanatomy, histopathogenesis, and diagnosis.

Ankle sprains are among the most common injuries sustained by athletes and seen by sports medicine physicians. Despite their prevalence in society, ankle sprains still remain a difficult diagnostic and therapeutic challenge in the athlete, as well as in society in general. The purpose of this section of our two-part study is to review scope of the problem, the anatomy and biomechanics of the lateral ankle ligaments, review the pathoanatomical correlates of lateral ankle sprains, the histopathogenesis of ligament healing, and define the mechanisms of injury to understand the basis of our diagnostic approach to the patient with this common acute and chronic injury. We extensively review the diagnostic evaluation including historical information and physical examination, as well as options for supplementary radiographic examination. We further discuss the differential diagnosis of the patient with recurrent instability symptoms. This will also serve as the foundation for part two of our study, which is to understand the rationale for our treatment approach for this common problem.

Lateral ankle sprains: a comprehensive review part 2: treatment and rehabilitation with an emphasis on the athlete.

This is the second part of a two-part comprehensive review of lateral ankle sprains. In the first part of our review, we discussed the etiology, natural history, pathoanatomy, mechanism of injury, histopathogenesis of healing, and diagnostic approach to acute and chronic lateral ligamentous ankle injuries. Conservative intervention and treatment of grade I-III and chronic, recurrent sprains of the lateral ankle ligaments and appropriate rehabilitation guidelines are the topics of this article. We review the use and benefit of different modalities and external supports and outline our five-phase intervention program of rehabilitation based on the histopathogenesis of ligament healing. We discuss the expected timing of recovery of the acute injury as well as the management of chronic, recurrent ankle sprains. Treatment of acute ankle sprains depends on the severity of the injury. Conservative therapy has been found to be uniformly effective in treating grade I and II ankle sprains. Some controversy exists regarding the appropriate treatment of grade III injuries, particularly in high-level athletes. Our belief is that the majority of these patients may also be treated well with conservative management. Other options for the management of grade III sprains will be briefly discussed at the end of this article.

Failure properties of suture anchors in the glenoid and the effects of cortical thickness.

The ultimate pullout strength and fatigue properties of a screw-design suture anchor implanted in the anterior glenoid rim were investigated and compared with results from a nonscrew-design suture anchor. Twenty-two cadaveric glenoids were harvested and one to two anchors were implanted in the superior and inferior quadrants. Fifty-seven Statak 3.5 anchors (Zimmer, Warsaw, IN) were tested and compared with results obtained in a previous study on 50 Mitek GII anchors (Mitek Products, Inc, Westwood, MA). The specimens were mounted on an Instron fatigue testing machine (Instron Corp, Canton, MA) and cycled between preselected minimum and maximum loads until pullout. The Mitek GII maintained a higher pullout strength than the Statak 3.5 after cyclic loading. Cortical thickness at the implantation sites was measured, and found to decrease monotonically from superior to inferior positions. The ultimate pullout strength, and subsequently the fatigue life, of both types of suture anchors depended directly on cortical thickness. The significantly lower performance of both anchors when placed inferiorly emphasizes the importance of correct anchor selection, number, and placement in this region. All anchors settled during the first 10 to 100 cycles, resulting in partial exposure of the implant. Intraoperative cycling of the anchors before suture tying may be necessary to achieve complete settling and prevent subsequent loss of coaptation between capsule and glenoid. The study shows that for the anchors to last 1,000 cycles or more, less than 50% of the theoretical ultimate pullout strength should be applied cyclically. With aggressive early rehabilitation exercises, this significant decrease in fixation strength could shift reconstruction failure from suture breakage or soft tissue tearing to anchor pullout.

The utility of contrast-enhanced MRI in diagnosis of muscle injuries occult to conventional MRI.

PURPOSE: Our goal was to define the utility of contrast-enhanced MRI in the diagnosis of occult muscle injuries on T2 and STIR sequences. METHOD: We retrospectively reviewed the pre- and postcontrast MR studies of four professional athletes with a clinical diagnosis of suspected muscle injuries. RESULTS: The four cases demonstrated muscle strain injuries not visualized on the conventional T2 and STIR sequences but visualized on the postcontrast MR studies as areas of localized enhancement. CONCLUSION: We recommend the intravenous administration of gadolinium in the setting of clinically suspected muscle injuries not visualized on T2 and STIR sequences.

The relationship between passive joint laxity and functional outcome after anterior cruciate ligament injury.

Twenty patients with anterior cruciate ligament-deficient knees were studied. Ten patients returned to all sports activities (compensators) and 10 patients were not improved with nonoperative management and required surgical stabilization (noncompensators). Joint laxity was measured using a KT-2000 arthrometer (manual maximum Lachman). Subjects completed a Lysholm questionnaire and Knee Outcome Score. The International Knee Documentation Committee form was also completed. Patients also rated their knee function on a scale of 1 to 100. There was no difference in level and frequency of athletic activity between the two groups before their anterior cruciate ligament injuries as determined by the knee outcome score. The compensator group had a mean side-to-side difference of 3.25 mm at 89 N and the noncompensators had a mean difference of 3 mm preoperatively. Manual maximum tests gave side-to-side differences of 6.7 mm for the compensators and 6 mm for the noncompensators. There were no differences in laxity measures between groups. The correlation between knee outcome scores and side-to-side laxity measurements were not significant. Measurements of anterior laxity in anterior cruciate ligament-deficient patients were not correlated with measures of functional outcome used in this study. Functional outcome measurements that are partially based on joint laxity measures, such as the International Knee Documentation Committee form, may artificially overestimate the disability after anterior cruciate ligament rupture.

Endoscopic preperitoneal herniorrhaphy in professional athletes with groin pain.

INTRODUCTION: Surgical exploration of the groin with subsequent herniorrhaphy has been recommended for obscure groin pain in athletes. The purpose of this study was to evaluate the efficacy of endoscopic preperitoneal herniorrhaphy and, if indicated, contralateral groin exploration in professional athletes with groin pain. PATIENTS AND METHODS: Eight professional athletes presented with groin pain and underwent endoscopic preperitoneal herniorrhaphy between February 1994 and May 1996. All athletes were male with a median age of 25.1 years (range: 22-30). Seven of the athletes complained of unilateral groin pain while one patient had bilateral pain. Seven had undergone previous conservative treatment without success. Despite multiple examinations, only two patients had been diagnosed with hernias prior to referral to the surgeon. Of the remaining six patients, all were found to have small inguinal hernias in the symptomatic groin. Seven of the patients were noted to have bilateral pathology. RESULTS: Operative time averaged 55.3 min. All patients were ambulatory without significant difficulty within the first 24 h, discontinued oral narcotic use within 72 h of surgery, and were back to recreational activities within 1 week. Aerobic conditioning was resumed within a maximum of 2 weeks. Full conditioning and/or return to full competition occurred within a 2- to 3-week period. At the time of 4 week follow-up, all athletes reported no more than minimal postexertional discomfort, with near total relief of early postoperative symptoms. No athletes noted any impairment in their ability to perform at peak levels. CONCLUSIONS: Groin pain in athletes is a difficult problem requiring a multidisciplinary approach to diagnosis and treatment planning. Endoscopic preperitoneal herniorrhaphy is an effective treatment for obscure groin pain when the pain is associated with an inguinal hernia and allows for a short recovery time back to full athletic activity.

Fatigue properties of suture anchors in anterior shoulder reconstructions: Mitek GII.

Suture anchors have simplified anterior capsule labral reconstruction. During rehabilitation the shoulder goes through many repetitions of range of motion exercises. These exercises will repetitively submaximally load the anchor and in theory should reduce the pullout strength of the suture anchor. No published reports exist on the fatigue strengths and properties of one of the most commonly used anchors: Mitek GII suture anchors. Fifty trials of cyclic submaximal load were done on 22 cadaveric glenoids with an average age of 66.8 years (range, 40 to 90 years). At two to three different sites on the same specimen, the anchors were inserted according to manufacturer's specifications. The anchors were tested to failure on a Instron 1331 servohydraulic mechanical testing system at 2 Hertz sinusoidal loading pattern using steel sutures and a predetermined load. There were 22 (44%) tests performed in the superior quadrant and 28 (56%) tests in the inferior quadrant. All anchors pulled out, and no wires broke. There were statistically significant differences between the superior and inferior portion of the glenoid with regard to number of cycles to failure at a given maximum load. The anchors underwent an average of 6,220 cycles before pullout at an average load of 162 N (SD = 73 N). In the superior quadrant, the average ultimate pullout strength was 237 N (SD = 42 N), whereas in the inferior quadrant the average ultimate pullout strength was 126 N (SD = 36 N). Hence, the ultimate pullout strength of the Mitek GII anchor was significantly higher (P < .002) in the superior quadrant than in the inferior quadrant. Using a least squares regression analysis, it was possible to predict the fatigue life of the superiorly and inferiorly placed suture anchors over a wide range of cycles. The R-squared values for trendlines showed good reliability (superior R2 = 0.55; inferior R2 = 0.28). The fatigue life curves for the two different quadrants were normalized using the ultimate pullout strength. This new, universal curve predicts the fatigue life of the Mitek GII anchor as a percentage of the ultimate pullout strength for any selected location. For a clinically relevant number of cycles, no more than approximately 40% to 50% of the ultimate pullout strength of the suture anchor can be cyclically applied to the anchor to guarantee a life for the duration of rehabilitation. For the entire system, the inferiorly placed anchors dictate the amount of cyclically applied load the system can experience without failing, and rehabilitation should be adjusted accordingly.

How much does inferior capsular shift reduce shoulder volume?

The purpose of this study was to quantitate the effect of inferior capsular shift on shoulder volume. Four fresh frozen cadaveric shoulders were analyzed. Volume before and after shift was determined using 3 techniques: (1) Magnetic resonance imaging sequences were digitized to computer and analyzed for volume via a 35-mm camera using Cue 2 software. The capsule was delineated by contrast between light and dark regions. Volume was calculated by summing the total area of respective slices. (2) Ultrasound images, obtained after surgical exposure of the capsule, were digitized. Volume was calculated using the formula for a prolate ellipsoid. (3) An 18-gauge needle was used to inject and evacuate saline via an anterior approach. Quantity of aspirated fluid provided a direct measure of volume. Inferior capsular shift was performed. After the operation, measurements were repeated. Inferior capsular shift reduced volume in all shoulders with each technique. On average, inferior capsular shift reduced joint volume by 57 %). A measurable reduction in shoulder joint volume is an effect of capsular shift. This measurement may have clinical application if volume is an indicator of instability or laxity.

MR evaluation of the anterior cruciate ligament: value of axial images.

OBJECTIVE: To investigate the accuracy of diagnosing anterior cruciate ligament (ACL) tears with axial MR imaging. MATERIALS AND METHODS: Two blinded independent observers retrospectively reviewed axial T2 weighted or FSE fat suppressed imaging of the knee from 47 patients. Arthroscopy had demonstrated a complete tear of the ACL in 25 patients and a normal ACL in 22 patients. The two criteria used to diagnose ACL tears on sequential axial imaging were (a) lack of visualization of the ACL in its expected course or (b) focal increased signal in the expected course of the ACL. RESULTS: Observer 1 demonstrated a sensitivity of 92% (23 of 25) and a specificity of 100% (22 of 22) in diagnosing ACL tears (chi 2 = 39.6, p < 0.001). Observer 2 demonstrated a sensitivity of 92% (23 of 25) and a specificity of 82% (18 of 22) in diagnosing ACL tears (chi 2 = 26.1, p < 0.001). The Kappa value was 0.75 (agreement in 41 of 47 cases), indicating a high degree of intraobserver agreement. CONCLUSION: Axial T2 weighted or FSE fat suppressed imaging provides an accurate means of confirming the diagnosis of ACL tears.

Review of typical ice hockey injuries. Survey of the North American NHL and Hockey Canada versus European leagues.

Ice hockey is considered to be one of the fastest and roughest of all sports. Prospective injury reports of the North American National Hockey League, the Canadian Amateur Hockey Association and of several European teams (UdSSR, CSSR, Sweden and Switzerland) are reviewed to evaluate the patterns, anatomic locations, circumstances and sequelae of ice hockey-related injuries. Although different injury reporting systems are used in North America and Europe, knee injuries (sprains of the collateral ligaments) accounted for the majority of games missed (40%), followed by injuries to the shoulder (dislocation, acromio-clavicular joint separation, rotator cuff strain and tears, 20%), the groin (15%), and the back (10%). Mandatory helmets and face masks reduced the number of facial and eye injuries to a quarter from 1972 to 1983. The frequency of only concussion but also cervical spine lesions is increasing. The prevention of head, face, eye and neck injuries should mainly be accomplished by enforcement of current rules (mandatory helmets with face masks) and institution of new rules. Improvement in protective equipment would also have the effect of decreasing the frequency of injuries. Ice hockey is the fastest team sport and involves both finesse and controlled aggression. It is also considered to be one of the roughest of all sports. In recent years, ice hockey has grown tremendously in popularity, not only in the United States and in Canada but also in many European countries [1]. The number of both professional and amateur hockey players has increased with the expanding interest in the sport around the world [1].(ABSTRACT TRUNCATED AT 250 WORDS)

[The role of CT and MR in assessing the patient operated on for rectal carcinoma: the local recurrence of the disease]. / Ruolo della TC e della RM nella valutazione del paziente operato per carcinoma rettale: recidiva locale della malattia.

Computed tomography (CT) and magnetic resonance (MR) findings in a series of 27 patients treated surgically for rectal cancer (13 rectal amputations, 8 sphincter-saving resections and 6 with the Hartmann technique) and affected with local recurrence at the time of examination (1989-1993), were retrospectively reviewed. Every detected lesion was studied relative to morphologic features (shape, outline, surrounding tissue involvement, symmetric growth toward the mid-longitudinal plane), patterns of both CT contrast enhancement and MR signal intensity with different acquisition techniques. The most typical patterns of disease recurrence were: a roundish or nodular shape (the whole group of rectal amputations), irregular outline (25 of 27 cases), infiltrative growth (23 of 27), asymmetry (25 of 27), CT enhancement > 20 HU (24 of 27), medium-high MR signal intensity on T2-weighted images (26 of 27 cases). We report on 5 cases with no positive correlation between CT enhancement and MR signal on T2-weighted images, trying to correlate this disagreement with specific histopathologic patterns.

[Role of CT and RM in postoperative evaluation of the patient after rectal carcinoma surgery: postoperative anatomy and nonneoplastic sequelae]. / Ruolo della TC e della RM nella valutazione del paziente operato per carcinoma rettale: anatomia post-chirurgica e sequele non neoplastiche.

The CT and MRI findings in a series of 57 patients submitted to curative surgery for rectal cancer, 1989 to 1993, and locally free of disease at the time of examination, were retrospectively reviewed. Both postoperative anatomy and tissue repair features were studied relative to the different surgical approaches, i.e., rectum amputation, sphincter-saving resection, Hartmann technique. The retrospective analysis of CT and MR findings led to the identification of some signs rather typical of every predictable non-malignant postoperative event, with max accuracy when radiologic findings were correlated with clinical and laboratory findings, as well as with the results of baseline study performed about 3-6 months after surgery. Florid granulation tissue exhibited marked enhancement after i.v. contrast agent administration and high signal intensity on T2-weighted MR scans: such questionable findings as a pseudonodular pattern were often clarified on multiplanar MR images by the identification of normal anatomic structures within repairing scar tissue. The major features exhibited by fibrosis were low signal intensity on T2-weighted MR scans, laminar or spindle-like shape and some retraction of the surrounding tissues. Poor enhancement after i.v. contrast agent administration proved to be a less reliable diagnostic criterion. Abscesses were identified because of their water-like content and ring of peripheral enhancement, both easily demonstrated on CT scans. The differential diagnosis of necrotic colliquative recurrence required clinical correlation with a careful morphologic analysis of lesion outline. Non-colliquative inflammation exhibited no typical CT/MR features suggestive of diagnosis. Finally, radiation fibrosis was characterized by laminar pattern but its enhancement patterns and MR signal behavior were quite different from postoperative scar tissue: irregular enhancement spots and fairly high signal areas were often observed in these patients even months and years after radiation exposure.