OBJECTIVE: Recognizing melody in music involves detection of both the pitch intervals and the silence between sequentially presented sounds. This study tested the hypothesis that active musical training in adolescents facilitates the ability to passively detect sequential sound patterns compared to musically non-trained age-matched peers. METHODS: Twenty adolescents, aged 15-18 years, were divided into groups according to their musical training and current experience. A fixed order tone pattern was presented at various stimulus rates while electroencephalogram was recorded. The influence of musical training on passive auditory processing of the sound patterns was assessed using components of event-related brain potentials (ERPs). RESULTS: The mismatch negativity (MMN) ERP component was elicited in different stimulus onset asynchrony (SOA) conditions in non-musicians than musicians, indicating that musically active adolescents were able to detect sound patterns across longer time intervals than age-matched peers. CONCLUSIONS: Musical training facilitates detection of auditory patterns, allowing the ability to automatically recognize sequential sound patterns over longer time periods than non-musical counterparts.

The analysis of explosives with ion mobility spectrometry (IMS) directly from aqueous solutions was shown for the first time using an electrospray ionization technique. The IMS was operated in the negative mode at 250 degrees C and coupled with a quadrupole mass spectrometer to identify the observed IMS peaks. The IMS response characteristics of trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), 2-amino-4,6-dinitrotoluene (2-ADNT), 4-nitrotoluene (4-NT), trinitrobenzene (TNB), cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), cyclo-tetramethylene-tetranitramine (HMX), dinitro-ethyleneglycol (EGDN) and nitroglycerine (NG) were investigated. Several breakdown products, predominantly NO(2)(-) and NO(3)(-), were observed in the low-mass region. Nevertheless, all compounds with the exception of NG produced at least one ion related to the intact molecule and could therefore be selectively detected. For RDX and HMX the [M+Cl(-)](-) cluster ion was the main peak and the signal intensities could be greatly enhanced by the addition of small amounts of sodium chloride to the sprayed solutions. The reduced mobility constants (K(0)) were in good agreement with literature data obtained from experiments where the explosives were introduced into the IMS from the vapor phase. The detection limits were in the range of 15-190 mug l(-1) and all calibration curves showed good linearity. A mixture of TNT, RDX and HMX was used to demonstrate the high separation potential of the IMS system. Baseline separation of the three compounds was attained within a total analysis time of 6.4 s.

Background: Alcoholics Anonymous (AA) members represent an important and relatively understudied population for improving our understanding of alcohol dependence recovery as over 1 million Americans participate in the program. Further insight into coffee and cigarette use by these individuals is necessary given AA members' apparent widespread consumption and the recognized health consequences and psychopharmacological actions of these substances. Methods: Volunteers were sought from all open-AA meetings in Nashville, TN during the summer of 2007 to complete a questionnaire (n = 289, completion rate = 94.1%) including timeline followback for coffee, cigarette, and alcohol consumption; the Alcoholics Anonymous Affiliation Scale; coffee consumption and effects questions; the Fagerstrom Test for Nicotine Dependence (FTND); and the Smoking Effects Questionnaire. Results: Mean (+/-SD) age of onset of alcohol consumption was 15.4 +/- 4.2 years and mean lifetime alcohol consumption was 1026.0 +/- 772.8 kg ethanol. Median declared alcohol abstinence was 2.1 years (range: 0 days to 41.1 years) and median lifetime AA attendance was 1000.0 meetings (range: 4 to 44,209 meetings); average AA affiliation score was 7.6 +/- 1.5. Most (88.5%) individuals consumed coffee and approximately 33% of coffee consumers drank more than 4 cups per day (M = 3.9 +/- 3.9). The most common self-reported reasons for coffee consumption and coffee-associated behavioral changes were related to stimulatory effects. More than half (56.9%) of individuals in AA smoked cigarettes. Of those who smoked, 78.7% consumed at least half a pack of cigarettes per day (M = 21.8 +/- 12.3). Smokers' FTND scores were 5.8 +/- 2.4; over 60% of smokers were highly or very highly dependent. Reduced negative affect was the most important subjective effect of smoking. Conclusions: A greater proportion of AA participants drink coffee and smoke cigarettes in larger per capita amounts than observed in general U.S. populations. The effects of these products as described by AA participants suggest significant stimulation and negative affect reduction. Fundamental knowledge of the quantitative and qualitative aspects of coffee and cigarette consumption among AA members will enable future research to discern their impact on alcohol abstinence and recovery.

A careful history and physical examination are the cornerstones of orthopaedic sports medicine. When evaluating a patient for ligamentous instability of the knee joint, an understanding of the contribution of anatomic structures to stability enhances a practitioner's ability to achieve an accurate clinical diagnosis. This article reviews the various types of knee instability and the associated anatomic structures. Ultimately, information must be obtained from multiple tests to reach the final diagnosis. We describe in detail the pathologic and biomechanical basis of the tests for both tibiofemoral and patellofemoral instability of the knee joint and provide recommendations for performance and interpretation of these physical examinations.

PURPOSE: In 1998, four cases of contaminated allografts for anterior cruciate ligament (ACL) reconstruction resulted in Clostridium infection, and a patient with Clostridium infection from a femoral condylar allograft died. It was subsequently published that implanting surgeons should culture ACL allografts so that action could be taken should highly pathogenic bacteria be encountered. The purpose of this study is to test the hypothesis that ACL allograft cultures correlate with clinical infections. METHODS: Since October 2003, a single surgeon performing ACL reconstruction prospectively cultured all allografts in the operating room before implantation. After culture, grafts were thawed in warm saline mixed with bacitracin. All patients received a single dose of preoperative antibiotics. Final culture results were obtained in all patients, and all patients were followed for a minimum of 90 days to evaluate for postoperative infection. The cost of cultures was determined by multiplying hospital charges by the hospital cost-to-charges ratio. RESULTS: Two hundred and ten cases were included. Ten allografts (4.8%) had positive culture results (6 coagulase-negative Staphylococci, 1 alpha-Streptococcus-not-group-B, 1 Enterobacter, 1 Clostridium, and 1 polymicrobial [Klebsiella, Escherichia coli, and Enterococcus]). None of these patients had signs of infection; the three positive highly pathogenic bacteria (Enterobacter, Clostridium, and polymicrobial) graft recipients were treated with antibiotics. The others were observed. One patient with negative cultures developed Staphylococcus aureus infection. Mean culture cost was $127 (USD). CONCLUSIONS: Our results demonstrate that ACL allograft cultures do not correlate with clinical infections. LEVEL OF EVIDENCE: Level I, diagnostic study (testing of previously developed diagnostic criteria [culture]) in a series of consecutive patients (with universally applied reference gold standard [clinical evaluation for knee sepsis]).

BACKGROUND: Autologous chondrocyte implantation (ACI) is an expensive treatment option for focal cartilage defects, and commercial funding of research is associated with a study reaching a positive conclusion. The purpose of this analysis is to compare outcomes (and levels of evidence) between published ACI outcome studies that were commercially funded and studies that were not commercially funded. HYPOTHESIS: Commercially funded ACI literature could be commercially biased. STUDY DESIGN: Comparative meta-analysis. METHODS: MEDLINE was searched for human, knee, ACI, nonmembrane, English language, and clinical outcome studies. Studies were evaluated with regard to funding status (commercially funded or not commercially funded), outcomes, and levels of evidence. Outcomes and levels of evidence were evaluated and compared for commercially funded studies versus those that were not commercially funded. RESULTS: Twenty-three studies were included; 16 (70%) were commercially funded. Pooled clinical outcome measures data were not significantly different (Lysholm, Modified Cincinnati, patient-reported Cincinnati, Tegner, pain Visual Analog Scale) when comparing commercially funded studies with those that were not commercially funded. However, distribution of levels of evidence was significantly lower (P =.045) for commercially funded studies. CONCLUSION: Reassuringly, commercial funding of ACI studies did not result in a difference in published clinical outcomes versus those that were not commercially funded. However, the lower levels of evidence of commercially funded studies suggests that commercially funded ACI studies may be of less value to surgeons desiring to practice evidence-based medicine, and, in the future, commercial entities funding medical research could selectively fund studies of the highest levels of evidence.

PURPOSE: The superior-medial (SM) shoulder arthroscopic portal (Neviaser portal) is the portal anatomically closest to the suprascapular nerve, and any potential benefits of this portal would be mitigated if risk of suprascapular nerve injury were significant. The purpose of this study is to determine the safety of the SM arthroscopic shoulder portal. We hypothesize that the SM shoulder arthroscopic portal is safe. METHODS: Twelve fresh cadaveric shoulders were securely positioned to simulate shoulder arthroscopy in the beach-chair position with the arm at the patient's side in neutral rotation. An SM portal was established 1 cm medial to the acromion and 1 cm posterior to the clavicle, and a 5.5-mm burr sheath was oriented toward the acromioclavicular joint. The skin and trapezius were resected, the supraspinatus was retracted, and the suprascapular nerve was identified. The distance between the sheath and the nerve was measured by 2 independent observers with calipers. A safe distance was defined as 10 mm. RESULTS: The measured distances between the nerve and burr ranged from 18.5 to 35.7 mm, with a mean of 24.2 +/- 5 mm. The distance is significantly greater than the safe distance of 10 mm (P <.0001). CONCLUSIONS: This study shows that the SM portal is safe. The distance between an instrument oriented toward the acromioclavicular joint via the SM portal and the suprascapular nerve was 18.5 mm or greater in all specimens. CLINICAL RELEVANCE: Our study has clinical relevance because the SM portal is useful for arthroscopic rotator cuff repair, arthroscopic superior labrum repair, and arthroscopic distal clavicle excision.

Meniscus allotransplantation represents the biological solution for the symptomatic, meniscus-deficient patient who has not developed advanced osteoarthritis. A growing body of evidence suggests that pain relief and functional improvement may reliably be achieved at short- and medium-term follow-up, and even, in some cases, at long-term (>10 years) follow-up. Future research must address the issue of optimal timing of the procedure and whether meniscal transplantation results in demonstrable long-term benefits, especially with regard to protection of articular cartilage.

Arthroscopic reduction and internal fixation (ARIF) is recommended as state-of-the-art treatment for patients with pure compression fracture of the tibial plateau. We describe a new technique for ARIF of pure compression tibial plateau fractures that uses a cannulated, bioabsorbable interference screw. After a guide pin is placed in the center of the compressed fragment and a tamp is used to elevate the fracture (with bone grafting as desired), the interference screw is advanced over the guide pin, resulting in both elevation and buttressing of the fracture. As compared with previously described techniques in which percutaneous buttress screws were used, ARIF attained with an interference screw via the tibial metaphyseal window allows substantially improved efficiency of surgical steps, improved preservation of the soft tissue envelope, definitive articular reduction under arthroscopic visualization, use of a bioabsorbable implant, and elimination of the need for fluoroscopy.

Minimally invasive surgery-total knee arthroplasty (MIS-TKA) requires a skin incision of < or =5 inches (measured with the knee in full extension). A mini midvastus approach limits surgical dissection and resultant soft tissue trauma. The patella is subluxated laterally but not everted . MIS-TKA is technically challenging and instrument dependent. The design of cutting guides, sizers, and retractors must continue to evolve. Prospective, randomized controlled trials are required to test the hypothesis that MIS-TKA results in decreased patient morbidity and outcome equal to or better than traditional TKA. The purpose of this article is to describe the MIS-TKA technique.