bluuebunny/crossref_metadata_2025_split huggingface dataset:
Medial unicompartmental knee replacement in the under-50s
Authors: Parratte S. , Argenson J.-N. A. , Pearce O. , Pauly V. , Auquier P. , Aubaniac J.-M. 
Published: March 2009

We retrospectively reviewed 35 cemented unicompartmental knee replacements performed for medial unicompartmental osteoarthritis of the knee in 31 patients ≤50 years old (mean 46, 31 to 49). Patients were assessed clinically and radiologically using the Knee Society scores at a mean follow-up of 9.7 years (5 to 16) and survival at 12 years was calculated. The mean Knee Society Function Score improved from 54 points (25 to 64) pre-operatively to 89 (80 to 100) post-operatively (p < 0.0001). Six knees required revision, four for polyethylene wear treated with an isolated exchange of the tibial insert, one for aseptic loosening and one for progression of osteoarthritis. The 12-year survival according to Kaplan-Meier was 80.6% with revision for any reason as the endpoint. Despite encouraging clinical results, polyethylene wear remains a major concern affecting the survival of unicompartmental knee replacement in patients younger than 50.
Is there a biomechanical explanation for anterior knee pain in patients with patella alta?
Authors: Luyckx T. , Didden K. , Vandenneucker H. , Labey L. , Innocenti B. , Bellemans J. 
Published: March 2009

The purpose of this study was to test the hypothesis that patella alta leads to a less favourable situation in terms of patellofemoral contact force, contact area and contact pressure than the normal patellar position, and thereby gives rise to anterior knee pain.A dynamic knee simulator system based on the Oxford rig and allowing six degrees of freedom was adapted in order to simulate and record the dynamic loads during a knee squat from 30° to 120° flexion under physiological conditions. Five different configurations were studied, with variable predetermined patellar heights.The patellofemoral contact force increased with increasing knee flexion until contact occurred between the quadriceps tendon and the femoral trochlea, inducing load sharing. Patella alta caused a delay of this contact until deeper flexion. As a consequence, the maximal patellofemoral contact force and contact pressure increased significantly with increasing patellar height (p < 0.01). Patella alta was associated with the highest maximal patellofemoral contact force and contact pressure. When averaged across all flexion angles, a normal patellar position was associated with the lowest contact pressures.Our results indicate that there is a biomechanical reason for anterior knee pain in patients with patella alta.
Unipolar proximal femoral endoprosthetic replacement for tumour
Authors: Chandrasekar C. R. , Grimer R. J. , Carter S. R. , Tillman R. M. , Abudu A. , Jeys L. M. 
Published: March 2009

We undertook a cemental unipolar proximal femoral endoprosthetic replacement in 131 patients with a mean age of 50 years (2 to 84). Primary malignant tumours were present in 54 patients and 67 had metastatic disease. In addition, eight patients had either lymphoma or myeloma and two had non-oncological disorders. The mean follow-up was 27 months (0 to 180). An acetabular revision was required later in 14 patients, 12 of whom had been under the age of 21 years at the time of insertion of their original prosthesis. The risk of acetabular revision in patients over 21 years of age was 8% at five years compared with 36% in those aged under 21 years. All the unipolar hips in this younger age group required revision within 11 years of the initial operation. We conclude that unipolar replacement should not be used in younger patients and should be avoided in patients with a life expectancy of more than five years.
The risk of iatrogenic injury to the deep peroneal nerve in minimally invasive osteosynthesis of the tibia with the less invasive stabilisation system
Authors: Pichler W. , Grechenig W. , Tesch N. P. , Weinberg A. M. , Heidari N. , Clement H. 
Published: March 2009

Percutaneous stabilisation of tibial fractures by locking plates has become an accepted form of osteosynthesis. A potential disadvantage of this technique is the risk of damage to the neurovascular bundles in the anterior and peroneal compartments. Our aim in this anatomical study was to examine the relationship of the deep peroneal nerve to a percutaneously-inserted Less Invasive Stabilisation System tibial plate in the lower limbs of 18 cadavers. Screws were inserted through stab incisions. The neurovascular bundle was dissected to reveal its relationship to the plate and screws. In all cases, the deep peroneal nerve was in direct contact with the plate between the 11th and the 13th holes. In ten specimens the nerve crossed superficial to the plate, in six it was interposed between the plate and the bone and in the remaining two specimens it coursed at the edge of the plate. Percutaneous insertion of plates with more than ten holes is not recommended because of the risk of injury to the neurovascular structures. When longer plates are required we suggest distal exposure so that the neurovascular bundle may be displayed and protected.
Joint replacement in Malawi
Authors: Lubega N. , Mkandawire N. C. , Sibande G. C. , Norrish A. R. , Harrison W. J. 
Published: March 2009

In Africa the amount of joint replacement surgery is increasing, but the indications for operation and the age of the patients are considerably different from those in the developed world. New centres with variable standards of care and training of the surgeons are performing these procedures and it is important that a proper audit of this work is undertaken. In Malawi, we have pioneered a Registry which includes all joint replacements that have been carried out in the country. The data gathered include the age, gender, indication for operation, the prosthesis used, the surgical approach, the use of bone graft, the type of cement, pressurising systems and the thromboprophylaxis used. All patients have their clinical scores recorded pre-operatively and then after three and six months and at one year. Before operation all patients are counselled and on consent their HIV status is established allowing analysis of the effect of HIV on successful joint replacement. To date, 73 total hip replacements (THRs) have been carried out in 58 patients by four surgeons in four different hospitals. The most common indications for THR were avascular necrosis (35 hips) and osteoarthritis (22 hips). The information concerning 20 total knee replacements has also been added to the Registry.
Co‐occurrence of self‐reported disordered eating and self‐harm in UK university students
Authors: Wright Fiona , Bewick Bridgette M. , Barkham Michael , House Allan O. , Hill Andrew J. 
Published: March 2009

Objectives. Students are reported to have more symptoms of mental health problems than other young people. Disordered eating and self‐harm are common but evidence on comorbidity, especially in community samples, is limited. This study aimed to examine their co‐occurrence, onset timing, and the help‐seeking of UK university students.Methods. Two surveys were administered to undergraduate students at a single UK university. One was administered electronically (UNIversity Quality of Life and Learning survey) and completed by 5,045 students. The second, questionnaire‐based, was completed by 805 students (Student Well‐Being study). Both surveys included questions about disordered eating, self‐harm thoughts and behaviours, and psychological well‐being.Results. A strong relationship was found between reports of disordered eating and self‐harm, with co‐occurrence observed in 4.5 and 4.9% of students in the two surveys. Disordered eating and self‐harm often pre‐dated university entrance and there was no evidence of increasing levels of pathology by university year group. A younger age of onset of disordered eating behaviours was reported in those with co‐occurring disordered eating and self‐harm. Help‐seeking rates were low.Conclusions. The risk of co‐occurrence and earlier onset‐timing of disordered eating are consistent with a limited clinical literature. Information on co‐occurrence of mental health problems, their history, and low rates of help‐seeking identifies some of the challenge to universities and practitioners. These results suggest the value of access to screening resources and the involvement of service‐users in shaping the support provided.
Elevated expectancies among persons diagnosed with bipolar disorder
Authors: Johnson Sheri L. , Eisner Lori R. , Carver Charles S. 
Published: March 2009

ObjectiveStudents at risk for bipolar disorder endorse highly ambitious goals. This study examined expectations for the future among people with actual bipolar disorder, versus people with no history of mood disorder and persons with history of unipolar depression.MethodsOne hundred and three students were assessed for Axis I disorders and completed a measure of expected life outcomes.ResultsHistory of mania, but not history of depression, related to higher expectations of achieving popular fame and wealth.ConclusionsPeople with history of mania anticipate great success in domains involving public recognition.
Mindfulness‐based cognitive therapy may reduce thought suppression in previously suicidal participants: Findings from a preliminary study
Authors: Hepburn Silvia R. , Crane Catherine , Barnhofer Thorsten , Duggan Danielle S. , Fennell Melanie J. V. , Williams J. Mark G. 
Published: March 2009

ObjectivesThought suppression is a strategy aimed at mental control that may paradoxically increase the frequency of unwanted thoughts. This preliminary study examined effects of mindfulness‐based cognitive therapy (MBCT) on thought suppression and depression in individuals with past depression and suicidality.MethodsIn a randomized controlled trial design, 68 participants were allocated to an MBCT group or a treatment‐as‐usual waitlist control. Measures of thought suppression and depression were taken pre‐ and post‐treatment.ResultsMBCT did not reduce thought suppression as measured by the White Bear Suppression Inventory, but significantly reduced self‐reported attempts to suppress in the previous week.ConclusionsPreliminary evidence suggests that MBCT for suicidality may reduce thought suppression, but differential effects on thought suppression measures warrant further studies.
Sustained BMP Signaling in Osteoblasts Stimulates Bone Formation by Promoting Angiogenesis and Osteoblast Differentiation
Authors: Zhang Fengjie , Qiu Tao , Wu Xiangwei , Wan Chao , Shi Weibin , Wang Ying , Chen Jian-guo , Wan Mei , Clemens Thomas L , Cao Xu 
Published: March 2009

Abstract
Angiogenesis and bone formation are tightly coupled during the formation of the skeleton. Bone morphogenetic protein (BMP) signaling is required for both bone development and angiogenesis. We recently identified endosome-associated FYVE-domain protein (endofin) as a Smad anchor for BMP receptor activation. Endofin contains a protein-phosphatase pp1c binding domain, which negatively modulates BMP signals through dephosphorylation of the BMP type I receptor. A single point mutation of endofin (F872A) disrupts interaction between the catalytic subunit pp1c and sensitizes BMP signaling in vitro. To study the functional impact of this mutation in vivo, we targeted expression of an endofin (F872A) transgene to osteoblasts. Mice expressing this mutant transgene had increased levels of phosphorylated Smad1 in osteoblasts and showed increased bone formation. Trabecular bone volume was significantly increased in the transgenic mice compared with the wildtype littermates with corresponding increases in trabecular bone thickness and number. Interestingly, the transgenic mice also had a pronounced increase in the density of the bone vasculature measured using contrast-enhanced μCT imaging of Microfil-perfused bones. The vessel surface and volume were both increased in association with elevated levels of vascular endothelial growth factor (VEGF) in osteoblasts. Endothelial sprouting from the endofin (F872A) mutant embryonic metatarsals cultured ex vivo was increased compared with controls and was abolished by an addition of a VEGF neutralizing antibody. In conclusion, osteoblast targeted expression of a mutant endofin protein lacking the pp1c binding activity results in sustained signaling of the BMP type I receptor, which increases bone formation and skeletal angiogenesis.
Loss of Cbl-b Increases Osteoclast Bone-Resorbing Activity and Induces Osteopenia
Authors: Nakajima Arata , Sanjay Archana , Chiusaroli Riccardo , Adapala Naga Suresh , Neff Lynn , Itzsteink Cecile , Horne William C , Baron Roland 
Published: March 2009

Abstract
Cbl proteins are multifunctional adaptor molecules that modulate cellular activity by targeting the ubiquitylating system, endocytic complexes, and other effectors to a wide variety of regulatory proteins, especially activated receptor and nonreceptor tyrosine kinases. Cbl and Cbl-b perform unique functions in various cells, in addition to redundant functions that are required for embryonic development. We previously showed that eliminating Cbl impaired osteoclast motility, which modestly delayed embryonic bone development. We now report that Cbl-b−/− mice are osteopenic, because of increased bone resorption with little compensating increase in bone formation. In vitro bone-resorbing activity and differentiation of osteoclast-like cells (OCLs) were increased, as were some RANKL-induced signaling events (activation of NF-κB and the mitogen-activated protein kinases extracellular signal-regulated kinase [ERK] and p38), suggesting that specific RANKL-activated mechanisms contribute to the increased rate of differentiation and bone-resorbing activity. Re-expressing Cbl-b in Cbl-b−/− OCLs normalized the increased bone-resorbing activity and overexpressing Cbl-b in wildtype OCLs inhibited bone resorption. Cbl was without effect in either wildtype or Cbl-b−/− OCLs. Functional tyrosine kinase binding (TKB) and RING finger domains were required for the rescue by Cbl-b. Thus, both Cbl and Cbl-b perform regulatory functions in osteoclasts that are unique to one or the other protein (i.e., functions that cannot be compensated by the other homolog). One of Cbl-b's unique functions in osteoclasts is to downregulate bone resorption.
Promiscuous and Depolarization-Induced Immediate-Early Response Genes Are Induced by Mechanical Strain of Osteoblasts
Authors: Ott Claus-Eric , Bauer Sebastian , Manke Thomas , Ahrens Susan , Rödelsperger Christian , Grünhagen Johannes , Kornak Uwe , Duda Georg , Mundlos Stefan , Robinson Peter N 
Published: March 2009

Abstract
Whereas mechanical stimulation is essential for bone homeostasis, straining of larger magnitude promotes bone regeneration by directing cell differentiation and proliferation and influencing the gene expression patterns of osteoblasts, which play a vital role in fracture healing by producing and mineralizing osteoid matrix. To elucidate the molecular mechanisms underlying the response of osteoblasts to mechanical strains comparable to those occurring during bone regeneration, MC3T3 S4 (MC4) osteoblast-like cells were stretched in vitro. Analysis based on microarray expression profiling during the first 8 h after straining showed 674 differentially expressed genes. The response to mechanical strain can be divided in an immediate-early response (IER) and later responses. Examination of the ∼40 genes differentially expressed within the first 60 min, including 11 involved in regulating gene transcription, showed both promiscuous IER genes such as Fos that are upregulated by multiple extracellular stimuli, as well as a number of genes previously shown in neurons to be induced preferentially by depolarization (IPD-IER). Selected differentially expressed genes were validated after mechanical straining and KCl-induced depolarization. The effects of inhibitors for protein kinase A, mitogen-activated protein kinase, and calcineurin pathways were assessed in separate experiments by quantitative RT-PCR and shown to have differential effects on the response of MC4 cells and primary calvaria osteoblasts to both mechanical straining and KCl-induced depolarization. Therefore, our results showed the existence of two distinct pathways that mediate the IER of osteoblasts to large-magnitude mechanical straining and suggest that the IER to depolarizing stimuli is conserved in cell types as different as osteoblasts and neurons.
Is QUS or DXA Better for Predicting the 10-Year Absolute Risk of Fracture?
Authors: Moayyeri Alireza , Kaptoge Stephen , Dalzell Nichola , Bingham Sheila , Luben Robert N , Wareham Nicholas J , Reeve Jonathan , Khaw Kay Tee 
Published: March 2009

Abstract
Although quantitative ultrasound (QUS) is known to be correlated with BMD and bone structure, its long-term predictive power for fractures in comparison with DXA is unclear. We examined this in a sample of men and women in the European Prospective Investigation into Cancer (EPIC)-Norfolk who had both heel QUS and hip DXA between 1995 and 1997. From 1455 participants (703 men) 65–76 yr of age at baseline, 79 developed a fracture over 10.3 ± 1.4 yr of follow-up. In a sex-stratified Cox proportional-hazard model including age, height, body mass index, prior fracture, smoking, alcohol intake, and total hip BMD, a 1 SD decrease in BMD was associated with a hazard ratio (HR) for fracture of 2.26 (95% CI: 1.74–2.95). In the multivariable model with heel broadband ultrasound attenuation (BUA) in place of BMD, HR for a 1 SD decrease in BUA was 2.04 (95% CI: 1.55–2.69). Global measures of model fit showed relative superiority of the BMD model, whereas the area under the receiving operator characteristic (ROC) curve was slightly higher for the BUA model. Using both Cox models with BMD and BUA measures, we calculated exact 10-yr absolute risk of fracture for all participants and categorized them in groups of &lt;5%, 5% to &lt;15%, and ≥15%. Comparison of groupings based on two models showed a total reclassification of 28.8% of participants, with the greatest reclassification (∼40%) among the intermediate- and high-risk groups. This study shows that the power of QUS for prediction of fractures among the elderly is at least comparable to that of DXA. Given the feasibility and lower cost of ultrasound measurement in primary care, further studies to develop and validate models for prediction of 10-yr risk of fracture using clinical risk factors and QUS are recommended.
Ibandronate Prevents Bone Loss and Reduces Vertebral Fracture Risk in Male Cardiac Transplant Patients: A Randomized Double-Blind, Placebo-Controlled Trial
Authors: Fahrleitner-Pammer Astrid , Piswanger-Soelkner Jutta Claudia , Pieber Thomas Rudolf , Obermayer-Pietsch Barbara Maria , Pilz Stefan , Dimai Hans Peter , Prenner Guenther , Tscheliessnigg Karl-Heinz , Hauge Ellen , Portugaller Rupert Horst , Dobnig Harald 
Published: March 2009

Abstract
Bone loss and fractures are common complications after cardiac transplantation (CTP). The aim of this study was to investigate whether intravenous ibandronate is an effective preventive option. Thirty-five male cardiac transplant recipients received either ibandronate (IBN) 2 mg intravenously every 3 mo or matching placebo (CTR) in addition to 500 mg calcium carbonate and 400 IE vitamin D3. Sera were collected at CTP and every 3 mo thereafter. At baseline and 6 and 12 mo, standardized spinal X-rays and BMD measurements were taken. Bone biopsies were taken at CTP and after 6 mo from six patients. In the IBN group, 13% of the patients sustained a new morphometric vertebral fracture compared with 53% in the CTR group (absolute risk reduction [ARR], 40%; relative risk reduction [RRR], 75%; p = 0.04). BMD remained unchanged with IBN treatment but in the CTR group decreased at the lumbar spine by 25% and at the femoral neck by 23% (both p &lt; 0.0001) over the 1-yr period. Serum bone resorption markers carboxy-terminal telopeptide region of type I collagen (sCTX) and TRACP 5b were significantly increased in the CTR group and decreased in the IBN group at all time points compared with baseline. In contrast, both osteocalcin and bone-specific alkaline phosphatase levels showed, after a similar decrease over the first 3 mo in both groups, a marked rise in the CTR subjects and steadily declining levels in the IBN patients throughout the remainder of the study period. Three paired biopsies were available from each group. Despite the small sample size, a difference in the relative change of eroded surface (68% in the CTR versus −23% in the IBN group, p &lt; 0.05) could be shown. Intravenous IBN reduced fractures, preserved bone mass, and prevented uncoupling of bone formation and resorption after CTP. The favorable effects on bone turnover were also supported by histomorphometric findings.
Natural History and Correlates of Hip BMD Loss With Aging in Men of African Ancestry: The Tobago Bone Health Study
Authors: Sheu Yahtyng , Cauley Jane A , Wheeler Victor W , Patrick Alan L , Bunker Clareann H , Kammerer Candace M , Zmuda Joseph M 
Published: March 2009

Abstract
Little is known about the magnitude, pattern, and determinants of bone loss with advancing age among men, particularly among those of African descent. We examined the rate of decline in hip BMD and identified factors associated with BMD loss among 1478 Afro-Caribbean men ≥40 yr of age. BMD was measured at baseline and after an average of 4.4 yr by DXA. The rate of decline in femoral neck BMD was 0.29 ± 0.81%/yr in the total sample (p &lt; 0.0001). However, a U-shaped relationship between advancing age and the rate of decline in BMD was observed. The rate of decline in BMD at the femoral neck was −0.38 ± 0.77%/yr among men 40–44 yr of age, decelerated to −0.15 ± 0.81%/yr among men 50–54 yr of age, and then accelerated to −0.52 ± 0.90%/yr among those 75+ yr of age (all p &lt; 0.003). Men who lost ≥5% of their body weight during follow-up had significantly greater BMD loss than those who remained weight stable or gained weight (p &lt; 0.0001). The relationship between weight loss and BMD loss was more pronounced among men who were older and leaner at study entry (p &lt; 0.03). We also observed a strong impact of advanced prostate cancer and its treatment with androgen deprivation on BMD loss. Men of African ancestry experience substantial BMD loss with advancing age that seems to be comparable to the rate of loss among white men in other studies. Additional studies are needed to better define the natural history and factors underlying bone loss with aging in men of African ancestry.