Time filter

Source Type

Farmington, CT, United States

Owens B.D.,United States Military Academy | Nelson B.J.,University of Minnesota | Duffey M.L.,Pennsylvania State University | Mountcastle S.B.,University of Kansas Medical Center | And 4 more authors.
Journal of Bone and Joint Surgery - Series A | Year: 2010

Background: Relative to dislocations, glenohumeral subluxation events have received little attention in the literature, despite a high incidence in young athletes. The pathoanatomy of first-time, traumatic, anterior subluxation events has not been defined, to our knowledge. Methods: As part of a prospective evaluation of all cases of shoulder instability sustained during one academic year in a closed cohort of military academy cadets, a total of thirty-eight first-time, traumatic, anterior glenohumeral subluxation events were documented. Clinical subluxation events were defined as incomplete instability events that did not require a manual reduction maneuver. Twenty-seven of those events were evaluated with plain radiographs and magnetic resonance imaging within two weeks after the injury and constitute the cohort studied. Magnetic resonance imaging studies were independently evaluated by a musculoskeletal radiologist blinded to the clinical history. Arthroscopic findings were available for the fourteen patients who underwent arthroscopic surgery. Results: Of the twenty-seven patients who sustained a first-time, traumatic, anterior subluxation, twenty-two were male and five were female, and their mean age was twenty years. Plain radiographs revealed three osseous Bankart lesions and two Hill-Sachs lesions. Magnetic resonance imaging revealed a Bankart lesion in twenty-six of the twenty-seven patients and a Hill-Sachs lesion in twenty-five of the twenty-seven patients. Of the fourteen patients who underwent surgery, thirteen had a Bankart lesion noted during the procedure. Of the thirteen patients who chose nonoperative management, four experienced recurrent instability. Two of the thirteen patients left the academy for nonmedical reasons and were lost to follow-up. The remaining seven patients continued on active-duty service and had not sought care for a recurrent instability event at the time of writing. Conclusions: First-time, traumatic, anterior subluxation events result in a high rate of labral and Hill-Sachs lesions. These findings suggest that clinical subluxation events encompass a broad spectrum of incomplete events, including complete separations of the articular surfaces with spontaneous reduction. A high index of suspicion for this injury in young athletes is warranted, and magnetic resonance imaging may reveal a high rate of pathologic changes, suggesting that a complete, transient luxation of the glenohumeral joint has occurred. Copyright © 2010 by The Journal of Bone and Joint Surgery, Incorporated. Source

Lieberman J.R.,University of Southern California | Varthi A.G.,Yale University | Polkowski G.G.,New England Musculoskeletal Institute
Journal of Arthroplasty | Year: 2014

There is no consensus with respect to the best procedures to preserve the knee joint in patients with osteonecrosis of the knee. We performed a systematic review of the literature between 1999 and 2012. Only 10 of 1057 studies met our inclusion criteria. Core decompression prevented additional surgical treatment in pre-collapse knees with a failure rate of 10.4% (7 of 67 knees). Autogenous and osteochondral grafts decreased the need for additional surgery in both pre-collapse (0%, 20 of 20) and post-collapse knees (10.5%, 8 of 76 knees). Although these results are quite promising multi-center randomized trials are needed to identify the optimal procedures to treat this disease. © 2014 Elsevier Inc. Source

Dukas A.G.,New England Musculoskeletal Institute | Wolf J.M.,New England Musculoskeletal Institute
Hand Clinics | Year: 2015

Fractures involving the bones of the hand are among the most common injuries in the United States. A significant portion of these fractures are periarticular. Although the great majority of these fractures are treated successfully by nonoperative means, complications arise. We present a comprehensive review of prevention and management of complications of periarticular fractures of the distal interphalangeal, proximal interphalangeal, metacarpophalangeal, and carpometacarpal joints. © 2015 Elsevier Inc. Source

Brennan T.,Temple University | Adapala N.S.,Temple University | Adapala N.S.,New England Musculoskeletal Institute | Barbe M.F.,Temple University | And 3 more authors.
Calcified Tissue International | Year: 2011

Cbl is an adaptor protein and E3 ligase that plays both positive and negative roles in several signaling pathways that affect various cellular functions. Tyrosine 737 is unique to Cbl and phosphorylated by Src family kinases. Phosphorylated CblY737 creates a binding site for the p85 regulatory subunit of phosphatidylinositol 3 kinase (PI3K) that also plays an important role in the regulation of bone homeostasis. To investigate the role of Cbl-PI3K interaction in bone homeostasis, we examined knock-in mice in which the PI3K binding site on Cbl was ablated due to the substitution of tyrosine 737 to phenylalanine (Cbl YF/YF, YF mice). We previously reported that bone volume in these mice is increased due to decreased osteoclast function (Adapala et al., J Biol Chem 285:36745-36758, 19). Here, we report that YF mice also have increased bone formation and osteoblast numbers. In ex vivo cultures bone marrow-derived YF osteoblasts showed increased Col1A expression and their proliferation was also significantly augmented. Moreover, proliferation of MC3T3-E1 cells was increased after treatment with conditioned medium generated by culturing YF bone marrow stromal cells. Expression of stromal derived factor- 1 (SDF-1) was increased in YF bone marrow stromal cells compared to wild type. Increased immunostaining of SDF- 1 and CXCR4 was observed in YF bone marrow stromal cells compared to wild type. Treatment of YF condition medium with neutralizing anti-SDF-1 and anti-CXCR4 antibodies attenuated MC3T3-E1 cell proliferation. Cumulatively, these results show that abrogation of Cbl-PI3K interaction perturbs bone homeostasis, affecting both osteoclast function and osteoblast proliferation. © Springer Science+Business Media, LLC 2010. Source

Estus T.L.,University of Connecticut | Estus T.L.,New England Musculoskeletal Institute | Choudhary S.,New England Musculoskeletal Institute | Pilbeam C.C.,University of Connecticut | Pilbeam C.C.,New England Musculoskeletal Institute
Bone | Year: 2016

Bone marrow macrophages (BMMs), in the presence of cyclooxygenase-(Cox2) produced PGE2, secrete an inhibitory factor in response to Rankl that blocks PTH-stimulated osteoblastic differentiation. This study was to determine if the inhibitory factor also blocks PTH-stimulated Wnt signaling. Primary calvarial osteoblasts (POBs) were co-cultured with conditioned medium (CM) from Rankl-treated wild type (WT) BMMs, which make the inhibitory factor, and Cox2 knockout (KO) BMMs, which do not. PTH induced cAMP production was blocked by WT CM but not by KO CM. In the presence of KO CM, PTH induced phosphorylation at β-catenin serine sites, ser552 and ser675, previously shown to be phosphorylated by protein kinase A (PKA). Phosphorylation was blocked by WT CM and by H89, a PKA inhibitor. PTH did not increase total β-catenin. PTH-stimulated transcription factor/lymphoid enhancer-binding factor response element activity in POBs was blocked by WT CM and by serum amyloid A (SAA), the human recombinant analog of murine Saa3, which has recently been shown to be the inhibitory factor. In POBs cultured with Cox2 KO CM, PTH increased expression of multiple genes associated with the anabolic actions of PTH and decreased expression of Wnt antagonists. This differential regulation of gene expression was not seen in POBs cultured with WT CM. These data highlight the ability of PTH to phosphorylate β-catenin directly via PKA and demonstrate the ability of a Cox2-dependent inhibitory factor, secreted by Rankl-stimulated BMMs, to abrogate PTH stimulated β-catenin signaling. Our results suggest that PTH can stimulate a novel negative feedback of its anabolic actions by stimulating Rankl and Cox2 expression. © 2016 Elsevier Inc. Source

Discover hidden collaborations