John M. O’Donnell

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Norepinephrine (NE) is a neuromodulator that in multiple ways regulates the activity of neuronal and non-neuronal cells. NE participates in the rapid modulation of cortical circuits and cellular energy metabolism, and on a slower time scale in neuroplasticity and inflammation. Of the multiple sources of NE in the brain, the locus coeruleus (LC) plays a(More)
BACKGROUND Femoroacetabular impingement is a common cause of hip/groin symptoms and impaired functional performance in younger sporting populations and results from morphological abnormalities of the hip in which the proximal femur abuts against the acetabular rim. Many people with symptomatic femoroacetabular impingement undergo arthroscopic hip surgery to(More)
To determine the accuracy of MR imaging for the evaluation of the subscapularis tendon as well as define imaging findings that will increase accuracy. Retrospective review of the MR and operative (OR) reports of 286 patients was conducted and reviewed for the presence/degree (partial (PT)/full-thickness (FT)) of tearing; only PT articular tears were(More)
Most tears of the Ligamentum Teres (LT) are diagnosed when treating other hip pathologies. The purpose of this study was to evaluate the outcome of arthroscopic surgery for a unique group of patients with symptomatic isolated Ligamentum Teres rupture of the hip. The study included 29 patients who suffered from an isolated Ligamentum Teres rupture of the hip(More)
Ischiofemoral impingement (IFI) is an uncommon source of hip pain characterized by abnormal proximity of the lesser trochanter (LT) and the anterior border of ischium. The condition can be treated non-operatively but in severe cases, LT excision can provide beneficial results. Most previous descriptions for IFI operation use an open surgical approach but(More)
The authors tested the hypothesis that increasing the allotted testing time from two to four hours for the National Board of Medical Examiners medicine subject examination would increase the score on this examination when given as part of the clerkship evaluation. One-hundred six students who completed their medicine clerkships between September 1991 and(More)
We conducted the first comparison of dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) outcomes in adolescent girls with anorexia nervosa. We observed deficits in bone density by both tools. pQCT assessments were associated with many of the same clinical parameters as have been previously established for DXA.(More)
Online education has become increasingly popular for providing learning experiences in all disciplines. Despite continued evidence that online learning is at least equivalent to traditional methods, some educators are reluctant to embrace online educational offerings. This study evaluated whether an online class provided within an otherwise traditional(More)
The importance of the ligamentum teres (LT) in the hip is increasingly being recognized. However, the incidence of LT tears in the literature is extremely variable. Although classification systems exist their reliability in classifying LT pathology arthroscopically has not been well defined. To determine the inter- and intra-observer reliability of two(More)
Acetabular dysplasia is one of the most common sources of hip arthritis. With the recent innovation in hip arthroscopy, the question has been raised whether arthroscopy can be used to treat dysplastic hip conditions. The purposes of this systematic review are (i) describe the prevalence of intra-articular pathologies and (ii) report the outcomes of(More)