bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Pulsed Electromagnetic Field Frequencies on the Osteogenic Differentiation of Human Mesenchymal Stem Cells
Authors: Luo Fei , Hou Tianyong , Zhang Zehua , Xie Zhao , Wu Xuehui , Xu Jianzhong 
Published: April 2012

The purpose of this study was to evaluate the effect of different frequencies of pulsed electromagnetic fields on the osteogenic differentiation of human mesenchymal stem cells. Third-generation human mesenchymal stem cells were irradiated with different frequencies of pulsed electromagnetic fields, including 5, 25, 50, 75, 100, and 150 Hz, with a field intensity of 1.1 mT, for 30 minutes per day for 21 days. Changes in human mesenchymal stem cell morphology were observed using phase contrast microscopy. Alkaline phosphatase activity and osteocalcin expression were also determined to evaluate human mesenchymal stem cell osteogenic differentiation.Different effects were observed on human mesenchymal stem cell osteoblast induction following exposure to different pulsed electromagnetic field frequencies. Levels of human mesenchymal stem cell differentiation increased when the pulsed electromagnetic field frequency was increased from 5 hz to 50 hz, but the effect was weaker when the pulsed electromagnetic field frequency was increased from 50 Hz to 150 hz. The most significant effect on human mesenchymal stem cell differentiation was observed at of 50 hz.The results of the current study show that pulsed electromagnetic field frequency is an important factor with regard to the induction of human mesenchymal stem cell differentiation. Furthermore, a pulsed electromagnetic field frequency of 50 Hz was the most effective at inducing human mesenchymal stem cell osteoblast differentiation in vitro.
Heat Generated With Pegged or Keeled Glenoid Components Fixed With Defined Amounts of Cement
Authors: Martens Kelly A. , Edwards Sara L. , Omar Imran M. , Saltzman Matthew D. 
Published: April 2012

Glenoid component loosening is a common complication of total shoulder arthroplasty and has been associated with the progression of radiolucent lines at the glenoid bone–cement interface. Generation of heat during the exothermic reaction of cement curing may cause osteonecrosis of bone, potentially leading to the development of radiolucent lines. The purpose of this study was to measure the heat generated with various defined amounts of cement used for glenoid component fixation.
Ten fresh-frozen cadaver scapulas were randomized to receive a keeled or pegged component with 1, 2, 3, 5, or 7 g of cement for fixation. An infrared camera was used to record the surface temperature generated during the cement curing process to an accuracy of ±2.0°C. Computed tomography was used to evaluate the cement mantle. The maximum temperatures generated did not exceed the critical value for osteonecrosis (56°C) in any of the specimens. The 4 specimens without a complete mantle were those fixed with a smaller quantity of cement (1, 2, or 3 g), and the largest cement mantle thicknesses were observed with the use of 7 g of cement.
Up to 7 g of cement can be used without significant concern for thermal necrosis. Incomplete cement mantles were observed when ⩽3 g of cement was used for fixation. Our results suggest that surgeons should use >3 g of cement to avoid incomplete cement mantles and that up to 7 g of cement can safely be used for glenoid fixation.
Arthroscopic Pancapsular Plication for Multidirectional Shoulder Instability in Overhead Athletes
Authors: Ma Hsiao-Li , Huang Hui-Kuang , Chiang En-Rung , Wang Shih-Tein , Hung Shih-Chieh , Liu Chein-Lin 
Published: April 2012

Treating shoulder multidirectional instability with an open stabilization procedure has been reported to have good results. However, few studies exist of arthroscopic plication, especially in overhead athletes. The purpose of this study was to evaluate the clinical outcomes of arthroscopic pancapsular plication for multidirectional instability in overhead athletes.Twenty-three athletes with symptomatic multidirectional instability were treated with arthroscopic pancapsular plication and evaluated at a mean follow-up of 36.3 months (range, 24–61 months). Mean patient age was 23.3 years (range, 19–33 years). Functional outcomes were evaluated with the American Shoulder and Elbow Surgeons (ASES) score, Constant shoulder score, and Rowe instability score. The degree of pain and range of motion were also recorded. All postoperative functional scores were rated good to excellent, with an average ASES score of 88.4 (range, 82–95), average Constant shoulder score of 88.1 (range, 81–100), and average Rowe instability score of 86.7 (range, 80–100). Five patients returned to the same level of competitive sports, and 18 returned to a limited level. All patients were satisfied with the stability postoperatively. No significant change was observed in postoperative range of motion, but patients who returned to a limited level of sports had lower functional scores and more pain than did those who fully returned to sports.Arthroscopic pancapsular plication for treating multidirectional instability in overhead athletes can provide good stability. However, the low rate of return to a full level of overhead sports is a problem. Further evaluation of the benefits of this procedure for overhead athletes with symptomatic multidirectional instability is needed.
Characterization of Daptomycin-loaded Antibiotic Cement
Authors: Kaplan Lige , Kurdziel Michael , Baker Kevin C. , Verner James 
Published: April 2012

Antibiotics are commonly mixed with polymethylmethacrylate (PMMA) cement to suppress severe periprosthetic infections associated with total joint arthroplasty. The relationship between antibiotic concentration and the resulting elution kinetics remains unclear. The purpose of this study was to characterize the release of daptomycin from PMMA cement and the subsequent effects on mechanical properties.
Varying concentrations of daptomycin and tobramycin were vacuum mixed in commercially available PMMA and subjected to an in vitro elution period. High-performance liquid chromatography was used to quantify the concentration of the amount of daptomycin eluted at predetermined time points. Samples were subjected to compressive loading to analyze the effect of antibiotic concentration on cement mechanical properties. Daptomycin elution increased when initial tobramycin concentration was increased. Furthermore, the addition of antibiotics increased the compressive strength of the cement in the postelution period. The binary addition of tobramycin with daptomycin antibiotics modifies the elution and mechanical properties of PMMA bone cement. Based on the findings of our study, 2 g of daptomycin and 3.6 g of tobramycin per 40-g packet of cement should be used to promote daptomycin elution without sacrificing PMMA mechanical properties.
Nonoperative Treatment of Displaced Type II Odontoid Peg Fractures With a Philadelphia Collar
Authors: Singh Vinay , Banerjee Samik , Onukaogu Smart , Singh Pankaj , Leitao James 
Published: April 2012

Although a consensus exists on the nonoperative management of types I and III odontoid peg fractures, treatment of type II fractures remains controversial. An increasing trend exists toward primary fixation of type II peg fractures due to a high rate of nonunion, especially if the displacement is >4 mm. This article reports the results of nonoperative treatment of patients with displaced odontoid peg fractures (>4 mm) using a Philadelphia collar.
A retrospective review of clinical and radiological records was performed for nonoperatively treated patients who sustained displaced type II peg fractures between January 2003 and April 2008. The study group comprised 9 patients (2 men and 7 women), and all patients were treated with Philadelphia collars. Patients were followed up for an average of 24.8 months (range, 8–28 months) for clinical and radiological outcomes. Functional outcomes were measured according to the Smiley-Webster scale. Fractures united uneventfully in 6 patients, but nonunion developed in 3 patients. Average time to union was 12.3±2.94 weeks (95% confidence interval, 9.97–14.68 weeks; range, 10–16 weeks). No patient had clinical or radiological signs of instability or delayed onset myelopathy at follow-up. Three patients had excellent, 4 had good, and 2 had fair results as per the Smiley-Webster functional scoring system.
Displaced type II peg fractures can be managed nonoperatively in patients who refuse surgery or those with multiple comorbidities. Adequate patient counseling and compliance with close clinicoradiological follow-up is paramount to avoid adverse clinical events and achieve an optimal functional outcome.
Rate of Adverse Reactions to More Than 1 Series of Viscosupplementation
Authors: Webber Tracy A. , Webber Anthony E. , Matzkin Elizabeth 
Published: April 2012

Viscosupplementation, hyaluronic acid treatment, is an ancillary method for treating patients with symptomatic stage I or II osteoarthritis. Previous studies reported that local reactions occurred more frequently in patients receiving >1 course of treatment compared with patients receiving their first course of treatment. One (2%) of 42 first series patients and 4 (21%) of 19 of repeated series patients had adverse reactions severe enough to seek unscheduled care.
This study was performed to determine whether patients receiving >1 series of viscosupplementation had an increased adverse reaction rate. A retrospective chart review was performed on all patients who received >1 series of viscosupplementation during the study. A local adverse reaction was defined as acute swelling and pain in the knee, with no injury or trauma within 72 hours after hyaluronic acid injection.

Twenty-eight knees received >1 series of viscosupplementation. The adverse reaction rate to second series injections was 1.28% (3.57% of knees). The adverse reaction rate to ⩾3 series was 0.9% (6.67% of knees). This adverse reaction rate was significantly less than the 21% reported in previous studies for multiple series injections (
z
=−1.90;
P
<.05) and is not significantly different than the 2% rate of adverse reactions reported for first series injections. No significant difference existed in the adverse reaction rates between 2 series and ⩾3 series of viscosupplementation.

The current study suggests that the rate of adverse reaction was low at 1.28% of second series viscosupplementation.
Complete Anterior Knee Dislocation 16 Years After Cruciate-retaining Total Knee Arthroplasty
Authors: Sato Yusuke , Saito Masahiko , Akagi Ryuichiro , Suzuki Masahiko , Kobayashi Tatsuya , Sasho Takahisa 
Published: April 2012

Anterior dislocation after total knee arthroplasty (TKA) is rare; 9 cases have been reported in the English literature. Five patients sustained subluxation, with recurvatum as the clinical manifestation, and 4 patients sustained complete dislocation, usually accompanying other serious complications.
This article describes a case of complete dislocation that developed atraumatically 16 years after TKA and was characterized by dislocation in extension and spontaneous reduction in flexion. Revision TKA was planned, with several alternative procedures under consideration, ranging in degree of invasiveness from simple polyethylene exchange to conversion to a hinge-typed prosthesis. Intraoperatively, extensive areas of blackened synovium and posterior-dominant polyethylene wear existed medially and laterally. Considering the patient’s age of 82 years, low activity level in activities of daily living, edematous skin, and number of stable components, we performed simple polyethylene exchange to a cruciate-retaining component that left the partial metal defect in the tibial plate untouched. Successful outcome was achieved for >2 years. The dislocation mechanism was polyethylene thinning, leading to relative valgus and anteroposterior instability that aggravated the anterior cruciate ligament dysfunction, which is speculated as the inherent key causative factor in every TKA.
Complete dislocation, usually accompanying other complications, requires prompt treatment because the possibility of serious consequences exists. Due to the absence of a gold standard, the treatment of choice needs to be made on a case-by-case basis.
Deep External Pudendal Artery Injury After Percutaneous Adductor Tenotomy During THA in Ankylosing Spondylitis
Authors: Sandri Andrea , Egis Darior , Marino Marco Andrea , Perandini Simone , Bonetti Ingrid , Toso Mirko 
Published: April 2012

Arterial injuries following total hip arthroplasty (THA) are uncommon and are usually related to revision THA. Deep external pudendal artery injury and delayed bleeding due to percutaneous adductor tenotomy during THA has not been reported.
A 62-year-old man with bilateral hip osteoarthritis and ankylosing spondylitis was treated with right cementless THA. Persistent severely limited hip abduction after prosthetic implantation required a percutaneous adductor tenotomy, which was performed bilaterally. No clinical signs of bleeding existed postoperatively. On postoperative day 3, the patient had a hypotensive attack, his right anteromedial thigh at the tenotomy site was distended, and the hemoglobin was 5.9 g/dL. Computed tomography angiography of the iliac and femoral vessels showed a right hematoma medial to the common femoral artery, with active contrast extravasation. Volumetric data reconstruction revealed active bleeding from the right external pudendal artery into an inguinal collection. Angiography was performed by the standard Seldinger technique via the contralateral femoral artery. A guiding catheter was placed as near to the lesion as possible. A microcatheter system and microguidewire were used for superselective catheterization, and 2 embolization coils were used to control the bleeding. The patient remained hemodynamically stable and was discharged 12 days later. Two-year follow-up was uneventful.
The deep external pudendal artery may be injured during percutaneous adductor tenotomy, especially in patients with fragile arterial walls, and life-threatening complications may occur. Angiography and embolization are the best treatment options.
Acetabular Liner Revision Using an Anterolateral Approach
Authors: Shigemura Tomonori , Kishida Shunji , Akamura Junichin , Takeshita Munenori , Takazawa Makoto , Arada Yoshitadah 
Published: April 2012

Total hip arthroplasty (THA) is recognized as a successful treatment for degenerative hip joint disease. An epidemiological study using the National Hospital Discharge Survey in the United States reported that the number of primary THAs increased from 119,000 in 1990 to 193,000 in 2002. According to nationwide inpatient sample data, the demand for primary THA was estimated to increase from 208,600 in 2005 to 572,000 (174%) in 2030 in the United States. The number of revision THAs in the United States has subsequently increased and is projected to increase from 40,800 in 2005 to 96,700 in 2030. Because revision THAs have a higher incidence of dislocation than primary THAs, preserving the soft tissue, including the gluteus medius muscle, is more necessary at revision THA. However, to our knowledge, few studies have reported soft tissue damage at revision THA. An anterolateral modified Watson-Jones approach, which is between the hip abductor and the tensor fascia lata, preserves the abductor muscles.
This article describes 2 cases in which acetabular liner revision was performed through an anterolateral modified Watson-Jones approach. The anterolateral approach provided an excellent surgical field at acetabular liner revision, with no major complications, and has the possibility of being a useful for acetabular liner revision.
Neuritis Ossificans of the Radial Nerve
Authors: Muzaffar Nasir , Ahmad Nawaz , Bhat Aejaz , Shah Nissar 
Published: April 2012

Neuritis ossificans is a rare reactive process affecting the peripheral nerves that is challenging to diagnose and treat. The usual presentation is mononeuropathy, pain, variable weakness, and a palpable mass along the nerve distribution. A paucity of literature exists on this disorder. It is often confused with myositis ossificans; many cases in the literature have reported myositic masses that have caused neuropathies. Diagnosing neuritis ossificans requires a high degree of clinical suspicion and excellent radiological and histopathological evaluation. The exact etiology of neuritis ossificans is unclear, but repeated localized trauma may be a factor. Treatment is mostly surgical, although conservative management with drugs has been reported to give good relief. The chance of iatrogenic nerve damage during microsurgical excision is high.
This article describes a case of neuritis ossificans of the radial nerve, which was treated by surgical excision of the lesion without nerve resection. No iatrogenic neurodeficit occurred, and the patient made a full recovery.
Neuritis ossificans should be considered in the differential diagnosis of painful mononeuropathies, particularly at atypical sites for compression neuropathy. Surgical resection of the mass may relieve pain and improve strength if the nerve can be sufficiently spared. Enucleation of this rare lesion is possible without neural compromise and should be considered as a treatment option for neuritis ossificans.
Rotationally Asymmetric Multifocal IOL Implantation With and Without Capsular Tension Ring: Refractive and Visual Outcomes and Intraocular Optical Performance
Authors: Alió Jorge L. , Plaza-Puche Ana B. , Piñero David P. 
Published: April 2012

PURPOSE:
To ascertain whether the refractive, visual, and intraocular optical quality outcomes of a rotationally asymmetric multifocal intraocular lens (IOL) are enhanced by the use of a capsular tension ring.

METHODS:
Ninety consecutive eyes from 53 patients (age range: 36 to 82 years) were divided into two groups: the no ring group comprised 43 eyes implanted with the multifocal rotationally asymmetric Lentis Mplus LS-312 (Oculentis GmbH) without a capsular tension ring; and the ring group comprised 47 eyes with the same IOL with a capsular tension ring. Distance and near visual acuity and refractive outcomes were evaluated pre- and postoperatively. Contrast sensitivity, intraocular aberrations, and defocus curve were evaluated postoperatively.

RESULTS:

Significant postoperative differences between groups were found in sphere, spherical equivalent refraction, and near addition (
P
⩽.02). Regarding defocus curve, significantly better visual acuity was present in eyes with the capsular tension ring for intermediate vision conditions (
P
⩽.05). Intraocular aberrometry did not differ significantly between groups (
P
⩾.09).

CONCLUSIONS:
Refractive predictability and intermediate visual outcomes with the Lentis Mplus LS-312 IOL improved significantly when implanted in combination with a capsular tension ring.
Relative Value of Managed Wetlands and Tidal Marshlands for Wintering Northern Pintails
Authors: Coates Peter S. , Casazza Michael L. , Halstead Brian J. , Fleskes Joseph P. 
Published: April 2012

Abstract
Northern pintail Anas acuta (hereafter pintail) populations have declined substantially throughout the western United States since the 1970s, largely as a result of converting wetlands to cropland. Managed wetlands have been developed throughout the San Francisco Bay estuaries to provide wildlife habitat, particularly for waterfowl. Many of these areas were historically tidal baylands, and plans are underway to remove dikes and restore tidal action. The relationship between tidal baylands and waterfowl populations is poorly understood. Our objective was to provide information on selection and avoidance of managed and tidal marshland by pintails. During 1991–1993 and 1998–2000, we radiomarked and relocated 330 female pintails (relocations, n  = 11,574) at Suisun Marsh, California, the largest brackish water estuary within San Francisco Bay, to estimate resource selection functions during the nonbreeding months (winter). Using a distance-based modeling approach, we calculated selection functions for different ecological communities (e.g., tidal baylands) and investigated variation explained by time of day (day or night hours) to account for differences in pintail behavior (i.e., foraging vs. roosting). We found strong evidence for selection of managed wetlands. Pintails also avoided tidal marshes and bays and channels. We did not detect differences in selection function between day and night hours for managed wetlands, but the degree of avoidance of other habitats varied by time of day. We also found that areas subjected to tidal action did not influence the selection of immediately adjacent managed wetlands. In areas where tidal marsh is restored, improving habitat conditions in adjacent wetlands would likely increase local carrying capacities and offset the loss of wetland area.
13q Deletion syndrome and retinoblastoma in identical dichorionic diamniotic monozygotic twins
Authors: De Francesco Sonia , Galluzzi Paolo , Del Longo Alessandra , Piozzi Elena , Renieri Alessandra , Menicacci Cristina , Mari Francesca , Munier Francis , Hadjistilianou Theodora , Mastrangelo Domenico 
Published: April 2012

Purpose To report the case of identical dichorionic diamniotic female twins with unilateral retinoblastoma in 13q deletion syndrome. Methods Clinical and ophthalmoscopic evaluation, combination of multiple ligation-dependent probe amplification, array–comparative genomic hybridization analyses, and magnetic resonance imaging were performed. Results Peculiar facial features, marked hypotonia, gastroesophageal reflux, interatrial septal defect with left to right shunt and light dilatation of right chambers, 5th finger hypoplasia, 3rd-5th toes clinodactyly, 2nd toe overlapped to 3rd toe, and cutis marmorata were found. Ophthalmoscopic evaluation revealed unilateral retinoblastoma in both girls. Magnetic resonance imaging detected corpus callosum hypoplasia in both twins. A 34.4-Mb deletion involving bands 13q13.2-q21.33 and including the RB1 gene was identified in both twins. The deletion was not present in the DNA of their parents and older brother. Conclusions Dysmorphic features in children must be always suspicious of 13q deletion syndrome and a short ophthalmoscopic follow-up is necessary to detect the presence of a retinoblastoma.