Finite element analysis of the stability of retrograde intramedullary nail and plate-screw combinations for periprosthetic femoral fractures following total knee replacement

OBJECTIVE

Periprosthetic fractures following total knee replacement are rare but challenging. The goal of the treatment is to achieve the most stable fixation that allows early mobilization. Therefore, the aim of this study was to evaluate the biomechanical results of the use of different fixation systems in the treatment of distal femur periprosthetic fractures with finite element analysis.

MATERIALS AND METHODS

A total knee prosthesis was implanted in Sawbone femur models. A transverse fracture line was created in the supracondylar region and was fixed in four different groups. In group 1, fracture line fixation was fixed using retrograde intramedullary nailing. In group 2, fixation was applied using a lateral anatomic distal femoral. In group 3, in addition to the fixation made in group 1, a lateral anatomic distal femoral plate was used. In group 4, in addition to the fixation made in group 2, a 3.5 mm Limited Contact Dynamic Compression Plate (LC-DCP) was applied medially. Computed Tomography (CT) scans were taken of the created models and were converted to three-dimensional models. Axial and rotational loading forces were applied to all the created models.

RESULTS

The least deformation with axial loading was observed in the double plate group. Group 3 was determined to be more advantageous against rotational forces. The greatest movement in the fracture line was found in group 2. The application of the medial plate was determined to reduce the tension on the lateral plate and increase stability in the fracture line.

CONCLUSIONS

Combining a lateral anatomic plate with intramedullary nailing or a medial plate was seen to be biomechanically more advantageous than using a lateral plate or intramedullary nailing alone in the treatment of distal femoral periprosthetic fractures.

Management of anesthesia in pregnant women with pulmonary hypertension

OBJECTIVE

Pulmonary hypertension (PH) is a rare heart disease associated with high maternal and fetal mortality. This study aims to discuss anesthesia management and the fetal and maternal outcomes of patients with PH followed-up at our clinic.

PATIENTS AND METHODS

This study includes a retrospective analysis of 105 pregnant women with PH. The patients were classified according to the mean pulmonary artery pressure (mPAP) values measured at rest by transthoracic echocardiography. The first group included patients with an mPAP value between 25 and 49 mmHg, considered to have a mild PH, whereas patients with an mPAB value ≥50 mmHg were considered to have severe PH and were included in the second group.

RESULTS

When the patients were examined for etiology, the majority (n=84, 70.5%) were found to have type 2 PH. It was found that in pregnant women with severe PH, the diameters of the left atrium, right atrium, and right ventricle were significantly larger (p=0.008, p=0.04, and p=0.013, respectively), and the ejection fraction was also significantly lower (p=0.04).

CONCLUSIONS

Although there has been a partial decrease in mortality for PH in recent years, it is still a serious condition that requires a multidisciplinary approach and well-planned obstetric treatment.

Ocular biometry characteristics and its relationship with age, gender, spherical equivalent in Turkish children

Background

Studying ocular biometric parameters in different populations and determining the relationship with personal characteristics can provide valuable information about ocular growth and help provide a better understanding of refractive errors.

Aims

To describe distributions of ocular biometry and to evaluate its associations with age, gender, spheric equivalent in Turkish children.

Patients and Methods

In this prospective study 344 children aged 3-14 years were evaluated. Parameters studied included axial length (AL), anterior chamber depth (ACD), and mean corneal radius (CR) measured with optical biometry. Cycloplegic refraction values were obtained using autorefractometer. The change of biometric parameters according to age and gender were evaluated. The relationship between ocular biometry parameters with refraction and age was analyzed by linear regression.

Results

Mean spherical equivalent (SE), AL, ACD and AL/CR observed to be lowest in the preschooler group (P < 0.001). SE reduced with age, and a weak correlation observed between SE and age (r = -0.333). AL and ACD had moderate and weak positive correlations with age respectively (r = 0.511; r = 0.304). There were negative correlations between SE with AL, ACD and AL/CR (r = -0.826; r = -0.540; r = -0.886). The strongest correlation with SE among these parameters was identified for AL/CR. AL and ACD were higher in boys, while the CR was lower in girls (p < 0.001).

Conclusion

While AL in children in late schooler group is higher than European countries, it shows similar characteristics in early schooler group. In addition AL is lower in all age groups than Asian population sexcept preschooler group. With age AL increases, SE decreases and AL plays a key role in refractive development.

Assessment of the orbital structures using computed tomography in healthy adults

Objectives

In this study, we retrospectively evaluated the orbital and ocular dimensions using computed tomography (CT) scans in healthy adults.

Materials and Methods

This retrospective study included 302 Turkish adult individuals aged 20-76 years (158 males and 144 females), who underwent paranasal sinus or craniofacial CT due to headache or suspicion of sinusitis, but abnormal orbital or cranial CT findings were not detected. Linear and volumetric measurements of the orbital structures were performed in the sagittal, coronal, and axial planes on CT slices. The volume was estimated in cubic centimeters using the equation of the ellipsoid method. A total of 34 parameters were measured from both eyes of each individual using 14 different anatomical landmarks and analyzed by gender and age.

Results

Parameter values of orbital structures in males and females are shown in millimeters or cubic centimeters. In most of the 34 parameters that we evaluated, it was seen that males had statistically significant higher mean values than females (P < 0.05). Also, there was no statistically significant difference between the measurements of right and left orbits. The correlation with age was varied according to the 34 parameters. Interestingly enough, there were no statistically significant differences between the two genders for extraocular muscles thickness (except superior muscles group thickness-SMT) and left optic nerve thickness (LOT) (p > 0.05). The mean right superior muscles group thickness was 5.35 ± 0.85 mm in the male subjects and 4.64 ± 1.10 mm in the female subjects (P < 0.001). The mean left superior muscles group thickness (LSMT) was 5.28 ± 0.88 mm in the male subjects and 4.67 ± 1.16 mm in the female subjects (P < 0.001). The mean LOT was 6.15 ± 0.97 and 5.88 ± 1.07 mm in males and females, respectively (P = 0.099).

Conclusion

This study can be applied to the standardization of orbital morphometry in healthy adults.

MRI Predictors of Recurrence and Outcome after Acute Transverse Myelitis of Unidentified Etiology

BACKGROUND AND PURPOSE

The early prediction of recurrence after an initial event of transverse myelitis helps to guide preventive treatment and optimize outcomes. Our aim was to identify MR imaging findings predictive of relapse and poor outcome in patients with acute transverse myelitis of unidentified etiology.

MATERIALS AND METHODS

Spinal MRIs of 77 patients (mean age, 36.3 ± 20 years) diagnosed with acute transverse myelitis were evaluated retrospectively. Only the patients for whom an underlying cause of myelitis could not be identified within 3 months of symptom onset were included. Initial spinal MR images of patients were examined in terms of lesion extent, location and distribution, brain stem extension, cord expansion, T1 signal, contrast enhancement, and the presence of bright spotty lesions and the owl's eyes sign. The relapse rates and Kurtzke Expanded Disability Status Scale scores at least 1 year (range, 1-14 years) after a myelitis attack were also recorded. Associations of MR imaging findings with clinical variables were studied with univariate associations and binary log-linear regression. Differences were considered significant for P values < .05.

RESULTS

Twenty-seven patients (35.1%) eventually developed recurrent disease. Binary logistic regression revealed 3 main significant predictors of recurrence: cord expansion (OR, 5.30; 95% CI, 1.33-21.11), contrast enhancement (OR, 5.05; 95% CI, 1.25-20.34), and bright spotty lesions (OR, 3.63; 95% CI, 1.06-12.43). None of the imaging variables showed significant correlation with the disability scores.

CONCLUSIONS

Cord expansion, contrast enhancement, and the presence of bright spotty lesions could be used as early MR imaging predictors of relapse in patients with acute transverse myelitis of unidentified etiology. Collaborative studies with a larger number of patients are required to validate these findings.

Medial olivocochlear suppression in musicians versus non-musicians

The medial olivocochlear efferent (MOCE) branch synapses with outer hair cells (OHCs), and the efferent pathway can be activated via a contralateral acoustic stimulus (CAS). The activation of MOCE can change OHC motile responses and convert signals that are capable of controlling the sensitivity of the peripheral hearing system in a frequency-specific manner. The aim of this study was to examine the MOCE system activity in professional musicians using transient evoked otoacoustic emission test and CAS. Musician group showed stronger suppression in all frequency bands in the presence of CAS.

Brain MRI Findings in Pediatric-Onset Neuromyelitis Optica Spectrum Disorder: Challenges in Differentiation from Acute Disseminated Encephalomyelitis

BACKGROUND AND PURPOSE

Differentiating pediatric-onset neuromyelitis optica spectrum disorder from acute disseminated encephalomyelitis could be challenging, especially in cases presenting with only brain manifestations. Our purpose was to investigate brain MR imaging features that may help distinguish these 2 entities.

MATERIALS AND METHODS

We retrospectively examined initial brain MR imaging studies of 10 patients with pediatric-onset neuromyelitis optica spectrum disorder (female/male ratio, 7:3) and 10 patients with acute disseminated encephalomyelitis (female/male ratio, 2:8). The mean age of the patients was 10.3 ± 5.6 and 8.7 ± 5.3 years, respectively. Brain lesions were evaluated with respect to location, extent, expansion, T1 hypointensity, contrast enhancement/pattern, and diffusion characteristics. The χ² test (Yates or Fisher exact χ²tests) was used to compare differences between groups.

RESULTS

Cerebral subcortical ± juxtacortical and pons ± middle cerebellar peduncle were the most frequent locations involved in both neuromyelitis optica spectrum disorder (n = 5 and 4, respectively) and acute disseminated encephalomyelitis (n = 9 and 7, respectively). Thalamic lesions were more frequent in acute disseminated encephalomyelitis (P = .020) and were detected only in 1 patient with neuromyelitis optica spectrum disorder. None of the patients with neuromyelitis optica spectrum disorder had hypothalamic, internal capsule, or cortical lesions. The internal capsule involvement was found to be significantly different between groups (P = .033). There was no significant difference in terms of extent, expansion, T1 hypointensity, contrast enhancement/pattern, and diffusion characteristics.

CONCLUSIONS

Although there is a considerable overlap in brain MR imaging findings, thalamic and internal capsule involvement could be used to differentiate pediatric-onset neuromyelitis optica spectrum disorder from acute disseminated encephalomyelitis.

Brachial Plexus Ultrasound and MRI in Children with Brachial Plexus Birth Injury

BACKGROUND AND PURPOSE

Brachial plexus birth injury is caused by traction on the neck during delivery and results in flaccid palsy of an upper extremity commonly involving C5-C6 nerve roots. MR imaging and MR myelography help to assess the anatomic location, extent, and severity of brachial plexus injuries which influence the long-term prognosis along with the surgical decision making. Recently, sonography has been increasingly used as the imaging modality of choice for brachial plexus injuries. The aim of this study was to assess the degree of correlation among brachial plexus sonography, MR imaging, and surgical findings in children with brachial plexus birth injury.

MATERIALS AND METHODS

This prospective study included 55 consecutive patients (girls/boys = 32:23; mean age, 2.1 ± 0.8 months) with brachial plexus birth injury between May 2014 and April 2017. The patients were classified according to the Narakas classification and were followed up at 4- to 6-week intervals for recovery by the Modified Mallet system and sonography without specific preparation for evaluation. All patients had MR imaging under general anesthesia. Nerve root avulsion-retraction, pseudomeningocele, and periscalene soft tissue were accepted brachial plexus injury findings on imaging. Interobserver agreement for MR imaging and the agreement between imaging and surgical findings were estimated using the κ statistic. The diagnostic accuracy of sonography and MR imaging was calculated on the basis of the standard reference, which was the surgical findings.

RESULTS

Forty-three patients had pre- and postganglionic injury, 12 had only postganglionic injury findings, and 47% of patients underwent an operation. On sonography, no patients had preganglionic injury, but all patients had postganglionic injury findings. For postganglionic injury, the concordance rates between imaging and the surgical findings ranged from 84% to 100%, and the diagnostic accuracy of sonography and MR imaging was 89% and 100%, respectively. For preganglionic injury, the diagnostic accuracy of MR imaging was 92%. Interobserver agreement and the agreement between imaging and the surgical findings were almost perfect for postganglionic injury (κ = 0.81-1, P < .001).

CONCLUSIONS

High-resolution sonography can identify and locate the postganglionic injury associated with the upper and middle trunks. The ability of sonography to evaluate pre- and the postganglionic injury associated with the lower trunk was quite limited. Sonography can be used as a complement to MR imaging; thus, the duration of the MR imaging examination and the need for sedation can be reduced by sonography.

Spontaneous otoacoustic emission recordings during contralateral pure-tone activation of medial olivocochlear reflex

We hypothesized that cochlear frequency discrimination occurs through medial olivocochlear efferent (MOCE)-induced alterations in outer hair cell (OHC) electromotility, which is independent from basilar membrane traveling waves. After obtaining informed consent, volunteers with normal hearing (n = 10; mean age: 20.6 ± 1.2 years) and patients with unilateral deafness (n = 10; mean age: 30.2 ± 17.9 years) or bilateral deafness (n = 8; mean age: 30.7 ± 13.8 years) underwent a complete physical and audiological examination, and audiological tests including transient evoked otoacoustic emission and spontaneous otoacoustic emission (TEOAE and SOAE, respectively). SOAE recordings were performed during contralateral pure-tone stimuli at 1 and 3 kHz. SOAE recordings in the presence of contralateral pure-tone stimuli showed frequency-specific activation out of the initial frequency range of SOAE responses. Basilar membrane motion during pure-tone stimulation results from OHC activation by means of MOCE neurons rather than from a traveling wave. Eventually, frequency-specific responses obtained from SOAEs suggested that OHC electromotility may be responsible for frequency discrimination of the cochlea independently from basilar membrane motion.

Comparison of HbA1c analysers: Agilent 1100 HPLC using kits produced by Gordion Diagnostic (Turkey) with Premier Hb9210 using kits produced by Trinity Biotech (USA) in different patient groups

BACKGROUND

The aim of this study was to compare the performance of Agilent 1100 HPLC analyser using HbA1c kits manufactured by Gordion Diagnostic (Turkey) with that of Premier Hb9210 using the original kits for the measurement of HbA1c in different patient groups.

METHODS

Subjects were divided into four groups: Group 1 included 140 diabetic and non-diabetic subjects with normal urea and haemoglobin levels; Group 2 included 84 diabetic and non-diabetic subjects with high urea levels; Group 3 included 44 diabetic and non-diabetic subjects with iron deficiency anaemia; and Group 4 included 52 diabetic and non-diabetic subjects with high haemoglobin levels. EP Evaluator Release 8 program was used to evaluate the resultant data.

RESULTS

According to the comparison results of the two methods in all groups, there was an excellent correlation between the two methods (R>0.98). Moderate-low correlation was found between increased urea concentration and the difference of the two methods (R= -0.374, p = 0.0005). The difference between the methods was found to be increased with increased urea concentrations. This difference, although statistically significant, was within the permitted limits. The observed correlation between the difference of the two methods and the low and high haemoglobin concentrations was statistically non-significant (R = 0.149, p = 0.3343; R = 0.263, p = 0.0594).

CONCLUSIONS

We found that Agilent 1100 HbA1c analyser and Gordions' HbA1c kit comply with the clinical requirements and are suitable for HbA1c analysis at high levels of urea and Hb and low levels of Hb in diabetic and non-diabetic patients.

Greater Efficiency Observed 12 Months Post-Implementation of an Automatic Tube Sorting and Registration System in a Core Laboratory

BACKGROUND

Sample classification and registration have been recognized as important and time-consuming processes in laboratories. There is increasing pressure on laboratories to automate processes due to intense workload and reduce manual procedures and errors. The aim of the present study was to evaluate the positive effects of an automatic tube registration and sorting system on specimen processing.

METHODS

An automatic tube registration and sorting system (HCTS2000 MK2, m-u-t AG, Wedel, Germany) was evaluated. Turnaround time (TAT), rate of sample rejection and unrealized tests were examined 12 months pre- and post-implementation of the automatic tube sorting and registration system.

RESULTS

The mean TAT of routine chemistry immunoassay, complete blood cell count (CBC) and coagulation samples were significantly improved (P<0.001). The number of rejected samples and unrealized tests was insignificantly decreased post-implementation of the system (0.4% to 0.2% and 4.5% to 1.4%, respectively) (P>0.05).

CONCLUSIONS

By reducing delays and errors in the preanalytical processing and sorting of samples, significant improvements in specimen processing were observed after implementation of the system. These results suggest that an automatic tube registration and sorting system may also be used to improve specimen processing in a higher-volume core laboratory.

Evaluation of the analytical performance of Unicel DXI 800 for the Total 25 (OH) Vitamin D measurements

OBJECTIVES

We assessed the analytical performance of newly developed Access 25(OH) Vitamin D Total assay with Beckman Coulter Unicel DXI 800 and evaluated the agreement between a reference method liquid chromatography/tandem mass spectrometry (LC-MS/MS) and a chemiluminescence method (LIAISON, DiaSorin).

DESIGN AND METHODS

160 serum samples were included. Deming Regression analysis and Bland-Altman plots were used. The concordance correlation coefficient (CCC) was used to assess the degree of agreement between assays and the reference method.

RESULTS

The CV% values of Unicel DXI 800 for within-run, between-run and between-day were lower than 6%. When compared to LC-MS/MS, the Access 25(OH) Vitamin D Total assay demonstrated an R value of 0.9444 (intercept -0.089, slope 0.951), with an average bias of -2.9%, and the LIAISON 25(OH) Vitamin D Total assay an R value of 0.9405 (intercept -0605, slope 0.924), with an average bias of -13.6%. In comparison with the LIAISON 25(OH) Vitamin D Total assay, the Access 25(OH) Vitamin D Total assay demonstrated an R value of 0.9498 (intercept 0.528, slope 1.029), with an average bias of 1.2%. The agreement with the LC-MS/MS method, based on values of the CCC, was moderate for the Unicel DXI 800 and LIAISON method (0.95, 0.94 respectively).

CONCLUSIONS

The new, automated Access 25(OH) Vitamin D Total assay showed an acceptable correlation with LC-MS/MS and LIAISON. Both methods moderately achieved to classify the patients according to their vitamin D status. However, we need further standardization of vitamin D assays to enhance the accuracy and comparability.

Efficacy of Ankaferd Blood Stopper on bone healing in diabetic rats: a stereological and histopathological study

We evaluated the effects of Ankaferd Blood Stopper (ABS) and routine antibiotic prophylaxis (AP) on early healing of bone defects in diabetic rats. We used 48 rats in the study. Diabetes was induced in 24 rats using streptozotocin; the remaining 24 healthy untreated rats served as controls. Twelve of the diabetic rats and 12 of the healthy rats were treated with AP for 3 days before surgery. Bilateral bone defects were created in the mandible of all animals. ABS was applied to the defects on the left sides of the mandibles, while nothing was applied to the right sides. Animals were sacrificed on days 7 and 14 after operation and examined for histopathology and by stereology. The volume of newly formed bone was significantly less in the diabetic rats on both days 7 and 14. Local administration of ABS significantly increased the mean volume of newly formed bone in both diabetic and nondiabetic rats at days 7 and 14. No significant difference in new bone formation was found between AP and ABS treatment in diabetic rats. Both AP and local administration of ABS have beneficial effects on bone healing in diabetic animals.

Shear bond strength of orthodontic attachments bonded to impacted teeth under in vivo and in vitro conditions

OBJECTIVES

To evaluate and compare the shear bond strength (SBS) of stainless steel and gold-plated attachments to impacted lower third molars in vivo and in vitro with a light-cured orthodontic resin.

SETTING AND SAMPLE POPULATION

Sixteen patients with bilaterally full soft tissue impaction of lower third molars were recruited on a voluntary basis from an oral and maxillofacial surgery department.

MATERIALS AND METHODS

A split-arch technique was used. Following surgical exposure of the crown, the tooth was luxated but not extracted. Then, two attachments (one stainless steel button and one gold-plated eyelet) were bonded to the labial enamel surface of the loosened tooth. Five minutes later, the luxated tooth was removed from its socket. In each patient, the impacted tooth on the other side was extracted, and attachments were bonded in vitro. The SBSs of the attachments were evaluated. For comparison, analysis of variance and multiple range tests were used (α = 0.05).

RESULTS

Statistically significant differences were evident in attachment adhesion to the impacted tooth surfaces among the four groups (p < 0.001). Superior SBS values were obtained for stainless steel button groups bonded in vitro. The mean bond strengths of the groups bonded in vitro were better than those of the same groups bonded in vivo.

CONCLUSIONS

Although the in vitro-bonded groups showed higher SBS values, adequate bond strength is possible with stainless steel buttons bonded in vivo.

Oral rehabilitation with endosseous implants in a child with ectodermal dysplasia: a case report

AIM

The purpose of this article is to report the clinical course of a 12-year-old child with ectodermal dysplasia who was treated with an implant-supported overdenture for the mandible and an overdenture for the maxilla.

CASE REPORT

Two dental implants were placed in the canine regions of the mandible. The maxillary teeth were prepared for the milled copings. Because the preparation of parallel walls was difficult, near-parallelism with an angle of convergence or taper of approximately 5 degrees was achieved. The cervical third of the teeth was prepared to be as parallel as possible to one another. In addition, the occlusal surfaces were reduced 1.5 mm, and the axial surfaces were reduced 1 mm. Occlusal reduction was performed to provide adequate thickness for the overlying denture base material. A chamfer finish line was prepared. The copings were cast with a Cr-Ni-based metal alloy and luted, bilateral balanced occlusion was developed using anatomic acrylic teeth. An impression was taken with an individual tray for impressions of overdentures. In response to the patient's dry mucosa, the impressions were taken using rapid-setting silicone impression material with high elasticity. Bilateral balanced occlusion was achieved using anatomic acrylic teeth for overdentures. The maxillary overdenture and implant-supported mandibular overdenture were prepared by conventional methods using thermal-curing acrylic resin. The patient was seen 48 hours later for adjustment, then after 1 and 2 weeks, 1, 3, and 6 months, and 1 year and he is still satisfied with his prosthesis both aesthetically and functionally.

CONCLUSION

The use of endosseous implants in the prosthetic rehabilitation of children with ectodermal dysplasia may provide a considerable improvement in comparison with traditional prosthetic methods.

An adenomatoid odontogenic tumor with unusual clinical features

Adenomatoid odontogenic tumors are uncommon odontogenic lesions characterized by duct-like structures that form from the epithelial component of the lesion. Most of these masses develop in the second or third decade of life, and there is a strong female bias in occurrence. Typically, these lesions arise in the lateral incisor/canine region of the maxilla, where they produce a swelling. Only in very rare cases is the lesion found distal to the premolar area. Nearly all of these growths are associated with an embedded anterior maxillary tooth (usually a canine), and most resemble a 1-3 cm diameter dentigerous cyst. Radiopacity is reported in two-thirds of cases. This article describes the case of a 9-year-old Caucasian male who presented with a painless swelling in the left premolar-molar region of his maxilla. This case is of particular interest because the features (patient age, gender, lesion location, size, and radiographic findings) were not typical of adenomatoid odontogenic tumor.

The value of routine antibiotic prophylaxis in mandibular third molar surgery: acute-phase protein levels as indicators of infection

Postoperative infections in the oral region are usually caused by anaerobic bacteria. While some authors claim that routine antibiotic prophylaxis is necessary after third molar surgery, others do not recommend this practice. The major subject of controversy is what constitutes postoperative infection. Previous studies that have examined the benefit of routine antibiotic prophylaxis have used several clinical symptoms (pain, swelling, and trismus) as indicators of infection; however, these clinical symptoms may be vague and unreliable, and cannot be evaluated scientifically. As a result, their use has only sparked more debate in this area of research. The present study assessed the value of routine antibiotic prophylaxis in impacted mandibular third molar surgery using acute-phase protein levels as potential indicators of early and late postoperative infection. Specifically, serum levels of C-reactive protein and alpha-1 antitrypsin were measured preoperatively and postoperatively in patients who received either prophylactic antibiotics or placebos. The results revealed no statistically significant difference between treated and control patients in terms of incidence of postoperative infection.

Cleidocranial dysplasia. Case report

A 29-year-old Caucasian woman who presented with short stature and multiple unerupted supernumerary teeth is described. Radiological investigations of her cranial and skeletal abnormalities revealed cleidocranial dysplasia. Because of the advanced age of the patient and contraindication for orthodontic treatment, only surgical and prosthetic treatment were performed. The characteristics and treatments of this rare autosomal dominant disorder are discussed.