睑袋成形术并发泪囊功能不全

目的 探讨睑袋成形术导致泪囊功能不全的原因和治疗方法。方法 对睑袋成形术后无睑外翻出现溢泪的患者，进行泪道功能检查，功能不全者行下睑睑部眼轮匝肌缩短或断端吻合，下睑眶部眼轮匝肌上移手术。结果 28例患者因睑袋成形术后并发泪囊功能不全，再次手术时均发现有过量切除或未能缩紧（或缩紧不足）睑部眼轮匝肌。经手术加强睑部眼轮匝肌张力后，泪囊“泵”功能恢复，溢泪消失。结论睑袋成形术中，对多余及松弛组织去除量的控制不当，或术中未能有效地恢复下睑各层结构张力的平衡，尤其是下睑睑部眼轮匝肌张力明显减弱时，其泪囊的“泵”作用消失，出现功能性溢泪。通过手术恢复下睑轮匝肌张力的“泪泵”功能，有效地治疗了因睑袋成形术所并发的泪囊功能不全。     

Calibration of an item pool for assessing the burden of headaches: An application of item response theory to the Headache Impact Test (HIT™)

Background: Measurement of headache impact is important in clinical trials, case detection, and the clinical monitoring of patients. Computerized adaptive testing (CAT) of headache impact has potential advantages over traditional fixed-length tests in terms of precision, relevance, real-time quality control and flexibility. Objective: To develop an item pool that can be used for a computerized adaptive test of headache impact. Methods: We analyzed responses to four well-known tests of headache impact from a population-based sample of recent headache sufferers (n = 1016). We used confirmatory factor analysis for categorical data and analyses based on item response theory (IRT). Results: In factor analyses, we found very high correlations between the factors hypothesized by the original test constructers, both within and between the original questionnaires. These results suggest that a single score of headache impact is sufficient. We established a pool of 47 items which fitted the generalized partial credit IRT model. By simulating a computerized adaptive health test we showed that an adaptive test of only five items had a very high concordance with the score based on all items and that different worst-case item selection scenarios did not lead to bias. Conclusion: We have established a headache impact item pool that can be used in CAT of headache impact.     

Creep dominates tensile fatigue damage of the cement-bone interface.

Fatigue damage from activities of daily living has been considered to be a major cause of aseptic loosening in cemented total hip arthroplasty. The cement-bone interface is one region where loosening could occur, but to date the fatigue response of the interface has not been examined. Cement-bone specimens were prepared from fresh frozen human cadaver tissue using simulated in vivo conditions. Tensile fatigue tests to failure were performed in an environmental chamber. Loss of specimen stiffness (stiffness damage) and permanent displacement after unloading (creep damage) were found in all specimens. At failure, creep damage accounted for the majority (79.9+/-10.6%) of the total strain damage accumulation at failure (apparent strain, epsilon=0.0114+/-0.00488). A power law relationship between strain-damage rate and time-to-failure showed that the strain-damage rate was an excellent predictor of the fatigue life of the cement-bone interface. The S-N response of the interface was obtained as a function of the applied stress ratio and the initial apparent strain. The total motion between cement and bone (72.2+/-29.8 microm) prior to incipient failure due to both stiffness and creep fatigue damage may be sufficient to result in fibrous tissue formation and contribute to eventual clinical loosening.     

张力带钢丝固定治疗髌骨骨折：附64例报告

我院自１９８５年应用张力带钢丝固定治疗６４例髌骨骨折。固定效果及功能恢复极其满意。经生物力学分析、证实此法优越于其它方法。文中介绍了手术方法并讨论了优点及适应征。     

颈后纵韧带张力性压迫症及手术治疗(附50例分析)

目的　用生物力学的观点认识颈后纵韧带张力性压迫症和手术技巧 ,从而提高临床疗效。方法　对 5 0例颈后纵韧带张力性压迫症患者施行了手术并进行分析。结果　发现颈后纵韧带由于病理性改变所出现的生物力学上的椎管内障碍 ,是影响脊髓功能的一个不可忽视的原因。结论　对于颈椎间盘突出、颈椎管狭窄症及颈前方压迫综合征的患者 ,在颈椎前手术的同时 ,采用彻底的切除该节段变性的颈后纵韧带 ,有较重要的临床应用价值     

The load of an implanted graft during and after fixation in anterior cruciate ligament reconstruction

Although the importance of initial graft load has been discussed in the literature, it has not been confirmed whether a surgeon can provide the desired load to an implanted graft in anterior cruciate ligament reconstruction. The purpose of this study was to compare the set force (initial load given to the graft before fixation) and residual load in the implanted graft using three different fixation techniques. A total of ninety porcine knees were tested using bone–patellar tendon–bone autograft. Each bone–tendon–bone autograft was fixed to the tibia with either the interference-fit screw, fixation post, or button technique. Graft load was monitored during fixation procedures, and for 10 min after fixation. Residual graft load with each fixation technique exhibited unique features. Highest graft load was obtained by the interference-screw fixation technique; however, the graft was usually over-loaded beyond the intended set force with this technique. In the fixation-post technique, the load of the graft increased while the screw was retightened. The graft load in the button-fixation technique was low, probably due to slight slippage of the button. When the graft was fixed under maximum manual tension, the graft loads at completion of fixation for the interference fit screw, fixation post, and button techniques were 116.3, 54.2, and 25.9 N respectively.     

无张力疝修补术治疗老年腹股沟疝54例临床分析

目的探讨应用疝环充填式无张力疝修补术治疗老年腹股沟疝的临床经验。方法回顾分析自2002年1月至2006年5月用美国Bard公司产品(Bard Mesh Perfix Plug)修补老年腹股沟疝共54例的临床资料。结果本组病例全部治愈。切口无感染,均为甲级愈合,恢复快,术后并发症少。随访1~14个月,无一例复发。结论疝环充填式无张力疝修补术保持了腹股沟管的正常解剖结构,具有手术创伤小,操作简便、省时、术后患者痛苦小、恢复快、复发率低等优点,是一种值得推广的手术方法。适合于老年疝的外科治疗。     

Altered tension cost in (TG(mREN-2)27) rats overexpressing the mouse renin gene

The present study aimed to characterize cardiac hypertrophy induced by activation of the renin–angiotensin system in terms of functional alterations on the level of the contractile proteins, employing transgenic rats harboring the mouse renin gene (TGR(mREN2)27). Ca²⁺-dependent tension and myosin ATPase activity were measured in skinned fiber preparations obtained from TGR(mREN2)27 and from age-matched Sprague–Dawley rats (SPDR). Western blots for troponin I (TnI) and troponin T (TnT) were performed and the phosphorylation status of TnI were evaluated in myocardial preparations. TnT and myosin heavy chain (MHC) isoforms were analyzed by RT-PCR. The pCa/tension relationship was shifted to the right in TGR(mREN2)27 compared to SPDR as indicated by increased Ca²⁺-concentrations required for half maximal activation of tension (SPDR 5.80, 95% confidence limits 5.77–5.82 vs. TGR(mREN2)27 5.69, 95% confidence limits 5.67–5.72, pCa units), while maximal developed tension was unaltered. Even more pronounced was the shift in the relationship between pCa and myosin–ATPase (SPDR 6.01, 95% confidence limits 5.99–6.03 vs. TGR(mREN2)27 5.77, 95% confidence limits 5.73–5.79, pCa units). The maximal myosin–ATPase activity was reduced in TGR(mREN2)27 compared to SPDR, respectively (211.0 ± 28.77 μmol ADP/s vs. 271.6 ± 43.66 μmol ADP/s, P < 0.05). Tension cost (ATPase activity/tension) was significantly reduced in TGR(mREN2)27. The β-MHC expression was significantly increased in TGR(mREN2)27. There was no isoform shift for TnT (protein and mRNA), as well as TnI, and no alteration of the phosphorylation of TnI in TGR(mREN2)27 compared to SPRD. The present study demonstrates that cardiac hypertrophy, induced by an activation of the renin–angiotensin system, leads to adapting alterations on the level of the contractile filaments, which reduce tension cost.     

运用654－2治疗张力性水泡的临床体会

运用６５４－２进行水泡内注射治疗张力性水泡２５例。结果表明，一旦发现张力性水泡，即行６５４－２泡内注射，从注射到泡内渗出液的吸收均在２４ｈ内，注射后局部无感染，无色素沉着。     

α-氰基丙烯酸正辛酯粘接胫骨中段蝶形骨折后骨块受力分析

目的：探讨α-氰基丙烯酸正辛酯粘接新鲜人胫骨中段蝶形骨块后,骨块所承受应力的力学特性。方法沿胫骨脊制作出占周径1/2的90°的蝶形骨折模型,α-氰基丙烯酸正辛酯粘接蝶形骨块后,测定骨块在拉伸、剪切、压缩等状态下直到胶体断裂时的应力数值及压缩状态下应力-应变曲线。结果α-氰基丙烯酸正辛酯粘接固定的蝶形骨块平均抗拉强度为1.04 MPa,抗剪切应力强度为3.26 MPa;在压缩载荷下,最大可承受47.2％的压缩应力,平均3.75 KN。结论采用α-氰基丙烯酸正辛酯粘接骨块,具有一定的生物力学强度。在临床操作中,可以减少骨折碎块固定时周围的软组织剥离,从而最大程度上保持骨折处的血供,有利于骨折的愈合。