Effects of Femoral Offset on Musculoskeletal Multi-Body Dynamics and Contact Mechanics of Artificial Hip Joint for DDH Patients / 医用生物力学

Objective To investigate the biomechanical effects of femoral offset (FO) on total hip arthroplasty (THA) patients with developmental dysplasia of the hip (DDH). Methods Based on the musculoskeletal dynamic software AnyBody and the related data from a female patient with Crowe Ⅳ DDH, the corresponding patient-specific lower extremity musculoskeletal multi-body dynamic model was constructed to analyze both hip joint forces and abductor forces within ±20 mm variation of FOs. The dynamic finite element (FE) model of S-ROM stem with varying offsets was also established. The dynamic load during a whole walking gait cycle calculated by the multi-body musculoskeletal model was applied to this FE models, and the Von Mises stress, contact stress, and stem-sleeve micromotion were then analyzed. Results A variation of ±20 mm offset had small influences on peak forces of hip joints. However, the decrease in FO could lead to an obvious increase in peak abductor force, while the increase in FO could lead to an obvious increase in the maximum Von Mises stress, contact stress, and micromotion of S-ROM prosthesis stem. Conclusions The change in FO had an obvious influence on the abductor forces, the maximum Von Mises stress, the contact pressure and the consequent fretting wear of THA patients with DDH, which should be carefully considered by surgeons.

Detection and analysis of an ATP2A2 mutation in a family with Darier-White disease / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular basis for a pedigree affected with Darier-White disease.@*METHODS@#Genomic DNA was isolated from 3 patients and 1 unaffected member from the pedigree, as well as 80 healthy controls. Targeted sequence capture and next-generation sequencing were used to screen mutations of skin disease-related genes. Candidate mutations were verified by Sanger sequencing, and co-segregation analysis was carried out to confirm the pathogenicity of mutation. Conservation analysis and protein structure and function were also predicted with Bioinformatic tools.@*RESULTS@#A heterozygous mutation c.2246G>T (p.G749V) was identified in exon 15 of ATP2A2 gene in all 3 patients from the pedigree, but not in the unaffected member or 80 healthy controls. The corresponding amino acid was highly conserved, and mutation of which can lead to structural and functional changes of the protein.@*CONCLUSION@#The c.2246G>T missense mutation of the ATP2A2 gene probably underlies the Darier-White disease in this pedigree by causing damages to the structure and function of sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2).

An Analysis of the Masking Curves and Residual Inhibition Effects of Tinnitus Patients at Different Age with Less Severe Hearing Loss / 听力学及言语疾病杂志

Objective To investigate the relationships between tinnitus masking curve types and tinnitus re-sidual inhibition in the patients at different ages with normal hearing ,mild ,moderate severe hearing loss .Methods The minimum masking levels and residual inhibition of 335 patients with normal hearing ,mild to medium ,and mod-erate to severe hearing loss were tested and analyzed using the method of psychological acoustics .Results Ages and the duration of residual inhibition had a corresponding relationship :the 19～30 years old group had corresponding relations with 0～40 seconds of residual inhibition ,while the 31～50 years old group with 81～100 seconds of resid-ual inhibition ,and the 50～63 years old group with 101～200 seconds of residual inhibition ,respectively .The 31～50 years old group and 51％ ～80％ residual inhibition had a corresponding relationship ;0％ ～30％ residual inhibi-tion group and parallel type of tinnitus masking curves had a corresponding relationship ,31％ ～50％ residual inhibi-tion group and separation type of the tinnitus masking curves had a corresponding relationship ,the groups of 51％ ～80％ and 81％ ～100％ residual inhibition with the types of convergent and overlapping tinnitus masking curves had corresponding relationship ,respectively .Conclusion There were different characteristics of tinnitus masking patients at different ages with different levels of hearing loss .The older people are ,the better effects and longer time of residual inhibition are .Those tinnitus patients with the tinnitus masking curve of convergent type and overlapping type showed a better tinnitus masking effect than the others .

Clinical research of sudden sensorineural hearing loss due to inner-ear hemorrhage / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>This study addresses the characters of magnetic resonance imaging (MRI) and clinical features, and curative effects in the screening of SSNHL due to inner-ear hemorrhage.</p><p><b>METHODS</b>MRI and relevant audiometric test were given to 160 patients with SSNHL, who were hospitalized in the First Affiliated Hospital of Sun Yat-sen University from January 2011 to April 2013. The clinical features and curative effects of patients with high signals in the labyrinth on MRI were analyzed.</p><p><b>RESULTS</b>MRI abnormities were found in 22 (13.8%) of the patients. Specifically, eight cases were considered for inner-ear hemorrhage. For the eight inner-ear hemorrhage cases, clinical features included the sudden onset of complete hearing loss, which worsened within several hours. Pure tone audiometry indicated profound sensorineural deafness. The prevalence of inner-ear hemorrhage was 5% in SSNHL cases and 18.6% in cases of profound sensorineural. MRI showed high signal intensity in the cochlear, semicircular canals or vestibule on unenhanced T1-weighted and fluid-attenuated inversion recovery images. The high signal intensity in the inner ear gradually degraded in six months. There was no improvement in hearing for the patients with inner-ear hemorrhage following symptomatic therapy.</p><p><b>CONCLUSION</b>SSNHL due to inner-ear hemorrhage is characterized by profound sensorineural deafness in all frequencies, and high signal intensity for the hemorrhagic inner ear on T1-weighted MRI, with poor prognosis.</p>

A study of applied microanatomy by endoscope-assisted via retrolabyrinthine approach / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To study the microanatomy by endoscope-assisted via retrolabyrinthine approach.@*METHOD@#Nineteen cadaveric heads fixed with formalin were dissected in our study. The data that endoscope could be extent and the distance between the important point were measured. By simulated the retrolabyrinthine approach, endoscope was placed to observe the nerves and vessels, the distance between nerves and the central point of the anterior edge of sigmoid sinus were measured.@*RESULT@#The distance from the inferior margin of petrous ridge to the upper bound of endolymphatic sac was (9.93+/-1.52)mm; and from superior margin of petrous ridge to the inferior margin common bony crus was (4.64+/-0.91)mm;and from the intersection of posterior semicircular canal to the anterior wall of sigmoid was (7.85+/-1.47)mm on the left, and (5.69+/-1.68)mm on the right. The distance from inferior margin common bony crus to the anterior wall of sigmoid was (13.9+/-1.71)mm on the left, and (11.31+/-2.03)mm on the right. The trochlear nerve and abducent nerve could be observed under endoscope. The relationship between the trigeminal nerve, acoustic nerve and the vessels could be identified clearly. The distance from the central point of the anterior edge of sigmoid to the roots of the trigeminal nerve, facial nerve, vestibulocochlear nerve and glossopharyngeal nerve were (29.88+/-2.77) mm, (32.04+/-2.04) mm, (29.17+/-1.65) mm, (35.49+/-1.53) mm respectively.@*CONCLUSION@#The visual field of the cerebellopontine angle appear wider by the endoscope assisted retrolabyrinthine approach. Nerves, vessel, internal acoustic pore, jugular foramen region can be clearly seen. Some minimal invasive surgery can be done by this approach.

Auditory steady-state response measurement in evaluating hearing loss milder than moderate to severe level / 中国组织工程研究

BACKGROUND: Auditory steady-state responses (ASSR) is an objective method of hearing examination in clinic in recent years. ASSR has the frequency specificity as compared with previous auditory brainstem responses (ABR).OBJECTIVE: To investigate the accuracy of ASSR in objective hearing assessment.DESIGN: A case-control observation.SETTING: Department of Otorhinolaryngology, the First Affiliated Hospital of Sun Yat-sen University.PARTICIPANTS: The subjects in the normal hearing group were the 21 undergraduates (42 ears) were enrolled, they all had not any symptoms of ear disease, without history of noise exposure and disease of vestibule system, and they were normal in otoscopy. The outpatients and inpatients with neurosensory deafness were selected from the Department of Otorhinolaryngology, the First Affiliated Hospital of Sun Yat-sen University. All the children cases worn hearing aids, and had the speech ability, and cooperated in the examination. The main types included 6 ears of sudden deafness,8 ears of presbycusis, and 20 ears of neurosensory deafness due to other unknown causes. Central lesions were excluded by MR examination, and all the patients agreed with the enrollment. The results of pure-tone audiometry were all flat or descending audiogram. According to the severity of hearing damage, the patients were divided into mild deafness group (13ears), moderate deafness group (9 ears) and moderate-to-severe deafness group (12 ears).METHODS: ① The pure-tone audiometry was performed at the frequencies of 0.125-8 000 Hz in a sound insulation room. The auditory threshold grades of the subjects with normal hearing all accorded with the standards of GB-7583-87 expected value distribution. The average value of air-conduction auditory thresholds of pure-tone audiometry at the frequencies of 0.5, 1, 2 and 4 kHz was calculated. ② ASSR measurement was performed with the synchronous stimulation pattern in a sound and electromagnetic shielding room, including 8 points for both ears of the same stimulation intensity and the carrier frequency tones of 0.5, 1, 2 and 4 kHz respectively.③ ABR examination was performed by click sounds with sparse waves in a sound and electromagnetic shielding room, and insert earphones were used.The threshold results were judged according to the minimal stimulation sound intensity of the distinguishable Ⅴ wave. ③ The results of pure-tone audiometry were compared with those of ABR examination, and the results of ASSR measurement in different hearing groups were processed with analysis of variance, multi-classification discrimination based Bayes standard and q test.MAIN OUTCOME MEASURES: The thresholds of pure-tone audiometry, ASSR measurement and ABR examination, and the correct rate analyzed by the multi-classification discrimination based Bayes standard were mainly observed.RESULTS: The indexes of the 42 ears in the normal hearing group, 13, 9 and 12 ears in the mild, moderate and moderate-to-severe deafness groups were all involved in the analysis of results. ① The ABR values were accorded with the actual hearing levels, and the closest to the ASSR thresholds at 1-2 kHz; ASSR reflected induction rates at different frequencies were gradually decreased with the aggravation of hearing damage, and that at each frequency varied with the changes of hearing level, the induction rates of ASSR responses were all 100% for the subjects with normal hearing and patients with mild deafness, but those for the patients with moderate and moderate-to-severe deafness were decreased (0.5 kHz: 77.8%,92.8%; 4 kHz: 88.9%, 85.7%). At different frequencies, the ASSR thresholds in the moderate-to-severe deafness group were significantly higher than those in the normal hearing group (P ＜ 0.05). The ASSR thresholds at 0.5 and 4 kHz in the moderate-to-severe deafness group were significantly higher than those in the mild deafness group (P ＜ 0.05). The ASSR threshold at 2 kHz in the mild deafness group was significantly higher than that in the normal hearing group (P ＜ 0.05). The ASSR thresholds at 4 kHz in the everedeafness group were significantly higher than those in the normal hearing group and mild deafness group. ② The incorrect discriminations of actual pure-tone audiometry were analyzed with the interactive clustering discriminant analysis of ASSR measurement and actual pure-tone audiometry, and the results showed that the correct rate of discrimination was 100% in the normal hearing group; Only 1 of the 12 cases in the mild deafness group was incorrectly judged, and the correct rate was 92%; Only 1 of the 19 cases in the moderate deafness group was incorrectly judged, and the correct rate was 89%; the correct rate in the moderateto-severe deafness group was 83%.CONCLUSION: The results of ASSR measurement can detect the incorrect discrimination of objective hearing condition by taking the results of pure-tone audiometry as the standards. ASSR has an acceptable accuracy for deafness higher than mild level in estimating objective hearing, and it has a better prospect of application in practice.

Intraoperative NRT Measurement During Cochlea Implant Surgery / 听力学及言语疾病杂志

Objective To explore the advantages of intraoperative NRT measurement(neural response telemetry)during cochlea implant surgery.Methods Intraoperative and postoperative NRT measurements were tested in ten SNHL children with CI24M-Nucleus and four SNHL children with CI24R(CS)-Nucleus, the ECAP threshold of intraoperative and postoperative measurements were compared, and the first maps were set up according to the intraoperative ECAP threshold.Results The average intraoperative ECAP threshold of 22 electrodes was higher than postoperative ECAP threshold, the average intraoperative ECAP threshold of CI24M-Nucleus' 22 electrodes was 11CL greater than postoperative ECAP threshold. It was just five minutes to record ECAP of 10 electrodes, and the beginning of fitting was finished in one hour.Conclusion It is confirmed that intraoperative NRT measurement could test the integrity of implants, and could estimate the first map. It is convenient to use and should be popularized.