Shoulder arthroscopy positioning: lateral decubitus versus beach chair.

Since the introduction of the beach chair position for shoulder arthroscopy, orthopaedic surgeons have debated whether the beach chair or lateral decubitus is superior. Most surgeons use the same patient position to perform all of their arthroscopic shoulder procedures, regardless of the pathology. Each position has its advantages and disadvantages. The evidence regarding the efficiency, efficacy, and risks of the lateral decubitus and the beach chair positions for shoulder arthroscopy does not show one position to be superior. This review presents a comparison of these positions with regard to setup, surgical visualization, access, and patient risk

Triceps Tendon Ruptures Requiring Surgical Repair in National Football League Players.

BACKGROUND: Complete triceps tendon ruptures are relatively rare in the general population but slightly more prevalent in professional football. One prior study found 11 complete ruptures over a 6-season period. HYPOTHESIS: Triceps ruptures occur more commonly in football linemen due to forced elbow flexion during an eccentric contraction and may occur more commonly with the increasing size and speed of professional players. Surgical repair allows full return to sports, but with a lengthy recovery time. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A search of the National Football League Injury Surveillance System (NFLISS) found a total of 37 triceps tendon ruptures requiring surgical repair from the years 2000 to 2009. Data were obtained for setting of injury, player position, activity causing injury, play type, time of game when injury occurred, height, weight, body mass index (BMI), and number of days lost from football. RESULTS: There were 37 players requiring surgical repair for triceps tendon ruptures over the 10-season period. The average height, weight, and BMI of the players were 75 inches, 292 pounds, and 36.5 kg/m(2), respectively. The majority of players were linemen (86%): 16 defensive, 15 offensive, and 1 tight end. The injury took place while blocking or being blocked in 29 players (78%) and while tackling or being tackled in 5 players (14%). Players missed an average of 165 days (range, 49-318 days) from football as a result of their injury and surgery. CONCLUSION: Triceps tendon tears requiring surgical repair are more common in professional football players than in the general population and are occurring more commonly than previously reported. Surgical repair allows return to play. CLINICAL RELEVANCE: Our study identifies the rate of triceps tendon tears requiring repair in the NFL according to position, identifying which players may be most at risk for this injury

Return to Play Criteria Following Operative Management of Acromioclavicular Joint Separation: A Systematic Review

Introduction: Acromioclavicular (AC) joint separation is a leading cause of shoulder injury among athletes. High grade injuries may require operative fixation, and comprehensive return to play guidelines have not yet been established. The purpose of this investigation is to summarize return to play criteria following operative management of AC joint separation. Methods: A systematic review of the literature was performed to evaluate clinical evidence regarding return to play following operative management of isolated AC joint separation. Studies satisfying inclusion criteria were analyzed for return to play timeline and other factors used to guide return to play following surgery. Results: Sixty-three studies with at least 1 explicitly stated return to play criterion were identified out of an initial database search of 1,253 published articles. Eight separate categories of return to play criteria were identified, the most common of which was time from surgery (95.2%). Return to play timelines ranged from 2 – 12 months, the most common timeline being 6 months (37.8%). Only 4 (6.3%) studies utilized conditional criteria to guide return to play, among which included range of motion, strength, clinical stability, radiographic stability, functional assessment, safety assessment, and hardware removal. Discussion: Most published studies utilize only time-based return to play criteria, and only a small number of studies employ patient-centered conditional criteria. While this systematic review helps provide a foundation for developing a comprehensive return to play checklist, further investigation is needed to establish safe and effective guidelines that will enable athletes to safely return to sport and minimize the recurrence of injury

Total Knee Arthroplasty in Patients with Prior Meniscus Surgery: A Matched Case Control Study

Introduction: Meniscus surgery is one of the most commonly performed orthopedic surgical procedures in the United States. However, outcomes following a Total Knee Arthroplasty (TKA) in patients with a history of prior knee arthroscopy are varied with small patient cohorts, warranting further research. The research question investigates how the clinical outcomes of TKA compare between patients with and without prior meniscectomy history. It is hypothesized that there will be no significant difference in clinical outcomes between the two cohorts. Methods: The study design is a retrospective case-control study. The study population included patients from Rothman Institute with TKA and prior meniscal surgery on the ipsilateral knee. Patients were matched on a 2:1 basis to the control group undergoing TKA without meniscal history. Physician chart notes, operative reports, and images were reviewed to compare outcomes. The outcomes were based on postoperative complications, including the rate of revision, re-operation, infection, and clinical outcome score. Results: 1028 patients met the inclusion criteria for the study population and were available for analysis. To date, 111 patients have been analyzed. Preliminary data shows that 97% (108) of the study population experienced no TKA complications. 2.7% (3) of the analyzed patients experienced TKA complications, warranting revision. Statistical analysis between the study and control group complication rates is pending. Discussion: The results implicate that there is no statistical difference between the two cohorts, which may support the hypothesis. This data might serve as a point of education for TKA patients and provide modifiable risk factors for meniscectomy patients

Functional Brain Networks Develop from a “Local to Distributed” Organization

The mature human brain is organized into a collection of specialized functional networks that flexibly interact to support various cognitive functions. Studies of development often attempt to identify the organizing principles that guide the maturation of these functional networks. In this report, we combine resting state functional connectivity MRI (rs-fcMRI), graph analysis, community detection, and spring-embedding visualization techniques to analyze four separate networks defined in earlier studies. As we have previously reported, we find, across development, a trend toward ‘segregation’ (a general decrease in correlation strength) between regions close in anatomical space and ‘integration’ (an increased correlation strength) between selected regions distant in space. The generalization of these earlier trends across multiple networks suggests that this is a general developmental principle for changes in functional connectivity that would extend to large-scale graph theoretic analyses of large-scale brain networks. Communities in children are predominantly arranged by anatomical proximity, while communities in adults predominantly reflect functional relationships, as defined from adult fMRI studies. In sum, over development, the organization of multiple functional networks shifts from a local anatomical emphasis in children to a more “distributed” architecture in young adults. We argue that this “local to distributed” developmental characterization has important implications for understanding the development of neural systems underlying cognition. Further, graph metrics (e.g., clustering coefficients and average path lengths) are similar in child and adult graphs, with both showing “small-world”-like properties, while community detection by modularity optimization reveals stable communities within the graphs that are clearly different between young children and young adults. These observations suggest that early school age children and adults both have relatively efficient systems that may solve similar information processing problems in divergent ways

Mother-infant interactions and regional brain volumes in infancy: an MRI study

Background: It is generally agreed that the human brain is responsive to environmental influences, and that the male brain may be particularly sensitive to early adversity. However, this is largely based on retrospective studies of older children and adolescents exposed to extreme environments in childhood. Less is understood about how normative variations in parent-child interactions are associated with the development of the infant brain in typical settings. Method: To address this, we used magnetic resonance imaging to investigate the relationship between observational measures of mother-infant interactions and regional brain volumes in a community sample of 3-6 month old infants (N=39). In addition, we examined whether this relationship differed in male and female infants. Results: We found that lower maternal sensitivity was correlated with smaller subcortical grey matter volumes in the whole sample, and that this was similar in both sexes. However, male infants who showed greater levels of positive communication and engagement during early interactions had smaller cerebellar volumes. Conclusion These preliminary findings suggest that variations in mother-infant interaction dimensions are associated with differences in infant brain development. Although the study is cross-sectional and causation cannot be inferred, the findings reveal a dynamic interaction between brain and environment that may be important when considering interventions to optimize infant outcomes

Measuring Granger Causality between Cortical Regions from Voxelwise fMRI BOLD Signals with LASSO

Functional brain network studies using the Blood Oxygen-Level Dependent (BOLD) signal from functional Magnetic Resonance Imaging (fMRI) are becoming increasingly prevalent in research on the neural basis of human cognition. An important problem in functional brain network analysis is to understand directed functional interactions between brain regions during cognitive performance. This problem has important implications for understanding top-down influences from frontal and parietal control regions to visual occipital cortex in visuospatial attention, the goal motivating the present study. A common approach to measuring directed functional interactions between two brain regions is to first create nodal signals by averaging the BOLD signals of all the voxels in each region, and to then measure directed functional interactions between the nodal signals. Another approach, that avoids averaging, is to measure directed functional interactions between all pairwise combinations of voxels in the two regions. Here we employ an alternative approach that avoids the drawbacks of both averaging and pairwise voxel measures. In this approach, we first use the Least Absolute Shrinkage Selection Operator (LASSO) to pre-select voxels for analysis, then compute a Multivariate Vector AutoRegressive (MVAR) model from the time series of the selected voxels, and finally compute summary Granger Causality (GC) statistics from the model to represent directed interregional interactions. We demonstrate the effectiveness of this approach on both simulated and empirical fMRI data. We also show that averaging regional BOLD activity to create a nodal signal may lead to biased GC estimation of directed interregional interactions. The approach presented here makes it feasible to compute GC between brain regions without the need for averaging. Our results suggest that in the analysis of functional brain networks, careful consideration must be given to the way that network nodes and edges are defined because those definitions may have important implications for the validity of the analysis

Refinement of 1p36 Alterations Not Involving PRDM16 in Myeloid and Lymphoid Malignancies

Fluorescence in situ hybridization was performed to characterize 81 cases of myeloid and lymphoid malignancies with cytogenetic 1p36 alterations not affecting the PRDM16 locus. In total, three subgroups were identified: balanced translocations (N = 27) and telomeric rearrangements (N = 15), both mainly observed in myeloid disorders; and unbalanced non-telomeric rearrangements (N = 39), mainly observed in lymphoid proliferations and frequently associated with a highly complex karyotype. The 1p36 rearrangement was isolated in 12 cases, mainly myeloid disorders. The breakpoints on 1p36 were more widely distributed than previously reported, but with identifiable rare breakpoint cluster regions, such as the TP73 locus. We also found novel partner loci on 1p36 for the known multi-partner genes HMGA2 and RUNX1. We precised the common terminal 1p36 deletion, which has been suggested to have an adverse prognosis, in B-cell lymphomas [follicular lymphomas and diffuse large B-cell lymphomas with t(14;18)(q32;q21) as well as follicular lymphomas without t(14;18)]. Intrachromosomal telomeric repetitive sequences were detected in at least half the cases of telomeric rearrangements. It is unclear how the latter rearrangements occurred and whether they represent oncogenic events or result from chromosomal instability during oncogenesis