AO Group Research Articles

Comparative Study of Two Aspheric, Aberration-Free Intraocular Lenses in Cataract Surgery

Purpose: To compare clinical outcomes of aberration-free MI60 intraocular lens (IOL) in microincision cataract surgery and an aberration-free intraocular lens, Akreos AO in conventional cataract surgery. Methods: Patients were randomly assigned to two IOL groups, and were examined preoperatively, and at one and three months postoperatively. The performed ophthalmologic evaluation included best corrected visual acuity (BCVA), measurement of refractive error, corneal astigmatism, and surgically induced astigmatism. The spherical, total, and higher-order aberration analysis of the two groups were assessed at one month and three months after operation. Results: MI60 IOL group provided significantly less corneal astigmatism (p=0.020) one month after operation, compared to Akreos AO group. The MI60 group also showed significantly less surgically-induced astigmatism at one month (p=0.021) and three months postoperatively (p=0.043). There was no statistically significant difference in the spherical, higher-order, and total aberration between the two groups at one and three months after operation. Conclusions: MI60 IOL group resulted in less corneal astigmatism and surgically induced corneal astigmatism than the Akreos AO IOL group. There was no statistically significant difference in spherical, higher-order, and total aberrations between the two groups.

The Tonal Classification of Chungli Ao Verbs

This paper presents an analysis of the tonal behavi our exhibited by verb stems in Chungli Ao, a Tibeto-Burman language of north-east India. Three verb stem classes are established, and their tonal properties, along with those of various inflectional suffixes, are examined within the framework of Autosegmental Phonology (Goldsmith 1976a, 1976b). 1. CHUNGLI AO Chungli is the prestige dialect of Ao, a Tibeto- Burman language spoken in Nagaland, a hill state in north-east India. Chungli speakers number around 90,000, while the related dialect of Mongsen has approximately 70,000 speakers (Coupe 2008). Although genetic classificat ion of the so-called Naga languages is far from settled, a recent tentative a ttempt categorizes these two dialects of with the languages of Yacham-Tengsa, Sangtam, Yimchungru, and Lotha to form the Ao Group (Burling 2003). Most of the linguistic on the Chungli variety of is from the late 19 th - early 20 th century, consisting of a missionary grammar (Clark 1893), a voluminous (977pp.) Ao-English dictionary (Clark 1911), and a short (23pp.) grammatical description (Avery 1886). None of these publications, however, indicates tone. More recent works by Gowda include a phonetic reader designed for non-native speakers (1972) and a sketch grammar (1975). Both of these works include indications of tone levels, but lack a detailed analysis of tonal phenomena. The previously-neglected Mongsen variety has received more attention lately with the publication of Coupe's phonetic and phonol ogical description of Mongsen as spoken in Waromung village (2003), which contains detailed phonetic measurements of segmental and tonal phenomena. Coupe's most thorough work, however, is a 526-page grammar of Mongsen as spoken in Mangmetong village (2007). This publication contains a short chapter devoted to prosody, describing lexical & morphological tone, t one sandhi, and intonation in Mongsen Ao. Though Coupe presents a few examples of internal tone sandhi triggered by verbal morphology, he concludes with t he disclaimer that a detailed analysis of these patterns lies outside the scope of the present work (2007: 72). The purpose of this paper, therefore, is to present a preliminary investigation of tonal phenomena in the verbal morphology of Chungli 1 . Although * Special thanks to Larry Hyman and Russell Rhodes for their assistance in conducting this

Effects of Various Drugs on Alcohol-induced Oxidative Stress in the Liver

The major aim of this work was to investigate how alcohol-induced oxidative stress in combined chemotherapy changes the metabolic function of the liver in experimental animals. This research was conducted to establish how bromocriptine, haloperidol and azithromycin, applied to the experimental model, affected the antioxidative status of the liver. The following parameters were determined: reduced glutathione, activities of glutathione peroxidase, glutathione reductase, peroxidase, catalase, xanthine oxidase and lipid peroxidation intensity. Alanine transaminase was measured in serum. Alcohol stress (AO group) reduced glutathione and the activity of xanthine oxidase and glutathione peroxidase, but increased catalase and alanine transaminase activity. The best protective effect was achieved with the bromocriptine (AB1 group), while other groups had similar effects on the studied parameters.

Cytokine profiling: A tool for predicting early MOF in trauma patients

ESULTS: 2258 patients included in the AO group, 2021 atients in the AO group. Demographics and injury severity ere similar. Incidence of VAP, sacral decubiti, wound dehisence, SIRS, renal failure and sepsis were similar between the roups. However, abdominal compartment syndrome (ACS) (90 s. 31, p 0.001), pulmonary failure (721 vs. 528, p 0.001), atheter related infections (75 vs. 50, p 0.004), and surgical site nfections (101 vs. 44, p 0.001) were significantly less in the O group.

Methods and results of external fixation in radius fractures

Both the radiocarpal and distal radioulnar joints are often affected in “distal radius fractures”. The incidence of this injury increases markedly among women over the age of 40. Bearing the wide variety of distal radius fractures in mind, a fixation system should be used which permits trans- and extraarticular application and subsequent reduction by means of distraction, as well as wrist mobilization and corrective osteotomies. It is important that both reduction and position of the carpal bones can be checked. This is possible using the double ball joint configuration with carpal height dimensioning. The possibility of extraarticular fixation should always be considered. AO group A.2 and A.3 fractures with sufficiently large fragments are suitable for this procedure. In other cases, transarticular application is advised. Complementary measures are justified in the case where two or more cortices in AP and lateral X-rays are destroyed. They are also used to stabilize the joint surface. Large bone defects should be filled with corticospongeous material.

Minimally Invasive Plate Osteosynthesis (MIPO): concepts and cases presented by AO East Asia

The Journal of Bone and Joint Surgery. British volumeVol. 89-B, No. 10 Book ReviewsFree AccessMinimally Invasive Plate Osteosynthesis (MIPO): concepts and cases presented by AO East Asia Edited by G. O. Tong and S. Bavonratanavech Pp. 370. New York: Thieme, 2006. ISBN: 3-13-143391-4. Euro 199.95.N. GearyN. GearySearch for more papers by this authorPublished Online:1 Oct 2007https://doi.org/10.1302/0301-620X.89B10.0891412aAboutSectionsPDF/EPUB ToolsDownload CitationsTrack CitationsPermissionsAdd to Favourites ShareShare onFacebookTwitterLinked InRedditEmail This AO instructional manual is a comendium of experience of the South-East Asian AO group. This book is well produced, eminently readable and the illustrations are clear and appropriate to the text. It should be a standard reference text in theatres and hospital libraries. The first third of the book deals with principles of minimally invasive fracture surgery and integrates this into updated AO principles. The latter two thirds cover specific techniques in relation to humeral, femoral, tibial and clavicular fractures. Icons at the top right corner of the page aid quick refernce by indicating the anatomical zone covered. It would have been helpful to differentiate more clearly the background basic science content of the first third.Purchase includes a DVD containing all the illustrations from the text which can be saved to your computer to illustrate your educational material. Illustrative animation on the DVD is referenced in the text by an icon but not to indicate when there is a video to illustrate a surgical approach. The videos are clear and well produced, but when run from the DVD menu, Quicktime runs in small form factor and does not have a full screen option. The reader would do better to run the videos directly from < Drive> :Applikation\Material\video in any MPEG player.It is never stated but slowly dawns on the viewer that this is a cadaveric workshop, not a surgical theatre. I can fault the content of the publication only in two minor areas. Having pointed out the proximity of the vessels to the middle third of the clavicle, and recommending general anaesthetic, the authors do not point out that as there is a risk of perforation of the subclavian vein, positive pressure ventilation should be recommended to avoid air embolism resulting from negative intra-thoracic pressure. Whilst the authors say that these plates seldom hav to be removed, it is necessary when an injured joint subsequently required prosthetic replacement. They point out that there are particular difficulties in removing the Locking Head Screws but specific techniques of removal are not described, (readers have to refer to AO Dialogue 4/06).This book is well produced, eminently readable and the illustrations are clear and appropriate to the text. It should be a standard reference text in theatres and hospital libraries.FiguresReferencesRelatedDetails Vol. 89-B, No. 10 Metrics Downloaded 222 times History Published online 1 October 2007 Published in print 1 October 2007 InformationCopyright © 2007, The British Editorial Society of Bone and Joint Surgery: All rights reservedPDF download

Antioxidant Supplementation and Immunoendocrine Responses to Prolonged Exercise

Antioxidant supplementation may modulate systemic cortisol and interleukin-6 (IL-6) responses to prolonged exercise, but it is unclear whether such effects are also associated with a reduction in the magnitude of immunodepression. The purpose of the present study was to examine the effects of daily vitamin C (L-ascorbic acid, 1000 mg x d(-1)) and vitamin E (RRR-alpha-tocopherol, 400 IU x d(-1)) supplementation on immunoendocrine responses to prolonged exercise. Twenty healthy, recreationally active males cycled for 2.5 h at approximately 60% of maximal oxygen uptake after 4 wk of placebo (PLA, N=10) or antioxidant (AO, N=10) supplementation. A significant group x time interaction was observed for plasma cortisol concentration (P=0.008), and the postexercise increase was greater (P<0.05) in the PLA compared with AO group (approximately 170% compared with an approximately 120% increase above baseline). Plasma IL-6 concentration was significantly increased after exercise to a similar extent in both groups. Plasma free F2-isoprostane concentration was significantly increased after exercise and was unaffected by AO supplementation, whereas plasma TBARS was unaffected by exercise in the PLA group but was lower after exercise in the AO group than in the PLA group. Circulating neutrophil count was significantly increased after exercise, and in vitro bacteria-stimulated elastase release per neutrophil was significantly decreased to a similar extent in both groups. These results suggest that 4 wk of AO supplementation may blunt the cortisol response to a single 2.5-h bout of prolonged exercise independently of changes in oxidative stress or plasma IL-6 concentration, but it is not effective at modulating the exercise-induced neutrophilia or depression of neutrophil function.

Complete Myocardial Revascularization Using Arterial Grafts Only in Patients with Unstable Angina: Impact on Early Outcome

The aims of this study were 1) to assess early clinical outcomes for patients with unstable angina (UA) who undergo urgent/emergent coronary artery bypass grafting (CABG); and 2) to evaluate the feasibility and safety of complete revascularization using strictly arterial grafts in this patient group. Between September 2001 and May 2005, a total of 961 patients underwent CABG at our center. One hundred and sixty-seven (17.4 %) of these individuals underwent urgent or emergent CABG because of UA, and 794 (82.6 %) underwent elective CABG for stable angina (SA). Of the 167 patients with UA, 59 (35.3 %) underwent complete revascularization using arterial grafts only (AO subgroup: internal thoracic arteries and radial arteries) and the other 108 received a combination of arterial and venous grafts (AV subgroup: 1 internal thoracic artery plus saphenous vein grafts). The UA group had a significantly higher proportion of women and a significantly higher rate of left main coronary artery disease than the SA group ( P = 0.016 and P = 0.0001, respectively). Cardiopulmonary bypass time was significantly longer in the UA group ( P = 0.01). Higher proportions of the UA group required inotropic support ( P = 0.001), intra-aortic balloon pump support ( P = 0.001), and re-exploration for bleeding or cardiac tamponade ( P = 0.005). This group also had a significantly longer mean time on mechanical ventilation ( P = 0.001) and a longer mean intensive care unit stay ( P = 0.01). The rates of operative mortality (first 30 days) in the SA and UA groups were 1.8 % and 6 %, respectively ( P = 0.001). There were no statistical differences between the AO and AV subgroups with respect to any of the preoperative or intraoperative findings. The AO group had a significantly shorter mean intensive care unit stay than the AV group ( P = 0.05). The AV group had a roughly fivefold higher operative mortality than the AO group (8.3 % vs. 1.7 %, respectively), but this difference was not statistically significant ( P = 0.17). Urgent or emergent CABG in the setting of UA is associated with increased but acceptable rates of mortality and morbidity. Complete myocardial revascularization using arterial grafts only (combinations of internal thoracic and radial arteries) is feasible and safe in this patient group.

Comparative study of the clinical results of metacarpal and phalangeal fractures fixed by AO miniplates and cross K-wires

目的 评价AO微型钢板和克氏针治疗掌、指骨骨折的疗效.方法共评价68例88处掌、指骨骨折病例,分为AO微型钢板组(26例37处)及交叉克氏针组(42例51处),随访3～12个月(平均5.3个月).以TAFS评分为评价标准.结果所有病例均达骨性愈合.AO微型钢板组TAFS评分中,优良率为78.4%;而交叉克氏针组为54.9%.两者的TAFS功能评分结果差异有统计学意义(x2=5.179,P<0.05),前者明显优于后者.AO微型钢板组延迟愈合率为2.70%;交叉克氏针组为7.84%,前者优于后者.AO微型钢板组平均骨折愈合时间为4.5周,交叉克氏针组为7.6周,两者结果差异有统计学意义(t=2.964,P<0.05),前者病例骨折愈合时间明显短于后者.两者术后感染率相似.结论 AO微型钢板治疗掌、指骨骨折在术后关节功能恢复情况、骨折延迟愈合率及骨折愈合时间、并发症发生等指标上明显优于交叉克氏针固定,但在术后感染率上无明显差异。

Antioxidants versus corticosteroids in the treatment of severe alcoholic hepatitis—A randomised clinical trial

Severe alcoholic hepatitis is associated with high morbidity and short-term mortality. Corticosteroids are the only widely used therapy but established contraindications to treatment or the risk of serious side-effects limit their use. The perceived need for alternative treatments together with the theoretical benefits of anti-oxidant therapy triggered the design of a randomised clinical trial comparing these treatment modalities. One hundred and one patients were randomized into a clinical trial of corticosteroids or a novel antioxidant cocktail with a primary endpoint of 30-day mortality. At 30 days there were 16 deaths (30%) in the corticosteroid treated group compared with 22 deaths (46%) in the antioxidant treated group (P=0.05). The odds of dying by 30 days were 2.4 greater for patients on antioxidants (95% confidence interval 1.0-5.6). A diagnosis of sepsis was made more frequently in the AO group (P=0.05), although microbiologically proven episodes of infection occurred more often in the CS group (P<0.01). The survival advantage for corticosteroid treated patients was lost at 1 year of follow-up (P=0.43). This study has shown that corticosteroids in the form of prednisolone 30 mg daily are superior to a broad antioxidant cocktail in the treatment of severe alcoholic hepatitis.

Antioxidant supplementation prevents exercise-induced lipid peroxidation, but not inflammation, in ultramarathon runners

To determine if 6 weeks of supplementation with vitamins E and C could alleviate exercise-induced lipid peroxidation and inflammation, we studied 22 runners during a 50 km ultramarathon. Subjects were randomly assigned to one of two groups: (1) placebos (PL) or (2) antioxidants (AO: 1000 mg vitamin C and 300 mg RRR-α-tocopheryl acetate). Blood samples were obtained prior to supplementation (baseline), after 3 weeks of supplementation, 1 h pre-, mid-, and postrace, 2 h postrace and for 6 days postrace. Plasma levels of α-tocopherol (α-TOH), ascorbic acid (AA), uric acid (UA), F 2-isoprostanes (F 2-IsoPs), tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), and C-reactive protein (CRP) were measured. With supplementation, plasma α-TOH and AA increased in the AO but not the PL group. Although F 2-IsoP levels were similar between groups at baseline, 28 ± 2 (PL) and 27 ± 3 pg/ml (AO), F 2-IsoPs increased during the run only in the PL group (41 ± 3 pg/ml). In PL women, F 2-IsoPs were elevated postrace ( p < .01), but returned to prerace concentrations by 2 h postrace. In PL men, F 2-IsoP concentrations were higher postrace, 2 h postrace, and 1, 2, 3, 4, and 6 days postrace (PL vs. AO group, each p < .03). Markers of inflammation were increased dramatically in response to the run regardless of treatment group. Thus, AO supplementation prevented endurance exercise-induced lipid peroxidation but had no effect on inflammatory markers.

Olecranon fractures--a reliable technique for accurate positioning of the tension band wire.

Background Tension band wiring as described by the AO group is the treatment of choice for simple displaced fractures of the olecranon.1 The most frequent complication of this procedure is symptomatic prominence of the wires.2 Most descriptions of this procedure emphasise the importance of inserting the Kirschner wires and the proximal loop of the tension band wire deep to the triceps tendon (Fig. 1) if such problems are to be minimised,1–4 but do not describe how to pass the proximal loop of the tension band wire.

Amaranth squalene reduces serum and liver lipid levels in rats fed a cholesterol diet

In this study, the hypocholesterolaemic effect of amaranth grain, oil and squalene are examined. In experiment 1, rats are given a semi-purified diet containing 1% (w/w) cholesterol for four weeks and either amaranth grain (AG; 300 g/kg) or amaranth oil (AO; 90 g/kg) substituted in experimental groups. Both AG and AO lowered serum and hepatic cholesterol and triglyceride levels. Faecal excretion of cholesterol and bile acid in the AO group increased, while AG ANected only bile acid excretion. In experiment 2, rats were fed the cholesterol diet for four weeks and injected (i.p.) with saline (control), amaranth squalene (AS) or shark liver squalene (SS, 200 mg/kg) for seven days. The hypolipidaemic effects of AS were evident in both serum and liver. In addition, AS markedly increased faecal excretions of cholesterol and bile acid, and slightly inhibited 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity. In contrast, none of these effects were observed in the SS group. This preliminary study suggests that the cholesterol-lowering effect of AS may be mediated by increased faecal elimination of steroids through interference with cholesterol absorption, and that different sources of squalene (plant versus animal) may ANect cholesterol metabolism differently.

Pseudoaneurysm of Superficial Femoral Artery Following Proximal Femoral Nail Fixation

Pseudoaneurysm of the femoral artery is a rare complication following the fixation of the fracture of proximal femur or protruded bony fragment and reports injuring on superficial femoral artery is very rare compared to deep femoral artery complicated by the insertion of distal interlocking screw. The chance of injuring superficial femoral artery may increase by deep insertion of drill bit or the repetitive arterial pulsation on prominent distal interlocking screw tip during the perioperative period. Authors experienced one case of injury on the superficial femoral artery postoperative 42 hours followed by the use of proximal femoral nail advocated by the AO group recently and would like to call attention upon the possibilities of vessel injury complicated with the use of the distal interlocking screw.

Surgical priorities in damage control in polytrauma.

©2003 British Editorial Society of Bone and Joint Surgery doi:10.1302/0301-620X.85B4.14217 $2.00 J Bone Joint Surg [Br] 2003;85-B:478-83. The management of the multiply-injured patient has been revolutionised during the past century. Advances in prehospital care, resuscitation, implants and intensive-care medicine have all contributed to better treatment of the patient in physiological crisis after trauma, who is at risk for the multiple-organ dysfunction syndrome and is battling for survival. The introduction of standardised surgical treatment for fractures in the early 1950s by the AO group and the implementation of advanced trauma life-support training were probably the greatest stimuli affecting the philosophy in the treatment of patients with polytrauma. However, more recent developments in molecular medicine and genetics have influenced our perception of management leading to the concept of ‘damage control orthopaedics’. While the basic concept of ‘save life limit disability’ has not changed, the type and timing of our interventions have been gradually modified. This review highlights the current concepts in the management of patients with multiple injuries with particular emphasis on the surgical priorities in damage control orthopaedics.

Hypocholesterolemic Effect of Amaranth Squalene (Amaranth esculantus) in Rats Fed a High Cholesterol Diet

In experiment 1, rats (n=6) fed diet containing 10 g/kg cholesterol for 4 wk (control) with either no amaranth (control), amaranth grain (300 g/kg, AG) or amaranth oil (90 g/kg, AO). Both the AG and AO groups had lower concentration of serum and hepatic cholesterol and triglyceride than the controls (p＜0.05). Fecal excretions of cholesterol and bile acid in AO group increased about 4 fold and 2 fold, respectively, while AG affected only bile acid excretion (p＜0.05). In experiment 2, rats (n=6) were fed the cholesterol diet for 4 wk and injected intraperitoneally with saline (control) or amaranth squalene (AS) for 7 d. The hypolipidemic effect of AS was evident in both serum and liver. Fecal excretions of cholesterol and bile acid were greater (p＜0.05) in AS than control. HMG - CoA (3 - hydroxy - 3 - methylglutaryl coenzyme A) reductase activity was reduced in AS group (11.6%, p=0.13). This study suggests that the cholesterol - lowering effect of AS is mediated by greater fecal elimination of steroids through interference with cholesterol absorption.

Classification and diagnosis of intracapsular fractures of the proximal femur.

Intracapsular fractures of the hip have been classified by different authors with a basis on various concepts. Pauwels classified these fractures according to the angle of inclination; Linton used trabecular disposition among the fractural fragments, and Garden described four types according to the order of displacement. The AO group used the comprehensive classification of fractures of the long bones and divided them among types, groups, and subgroups. However, the presence of posterior comminution of the femoral neck in intracapsular fractures as a factor foretelling instability was overlooked by each of the aforementioned classifications. With a basis on the factors previously described, the current authors developed a classification in which the criteria of instability in intracapsular fractures are given priority. Consequently, the characteristics of full or partial lines, angulation, displacement, and the presence of posterior comminution have been considered. Radiology is the first complementary study for diagnosis; it enables observation of the fracture line or trabecular changes in most cases and fragmental displacement and posterior comminution of the neck. In patients with stress fractures, radiographs often fail to show alterations, so a different diagnostic methodology is required. A diagnosis algorithm is presented. Differential diagnoses are focused toward diseases that may reveal images of pseudofractures.

Outcome quality in trauma surgery

Trauma surgery and orthopedic trauma surgery have been accompanied not only by internal quality assessment, but also by external quality assessment procedures right from the beginning. The reasons for these mechanisms were based on legal regulations of treatment of work-related accidents. In 1958, the Arbeitsgemeinschaft für Osteosynthese (Working Group on Osteosynthesis, AO group) was founded. The results of the AO's scientific activities built the basis of osteosyntheses. In 1988, legal regulations changed again in Germany. Since this reform of some important facets of public health care, each hospital or institution is committed to perform external and internal quality assessment. In addition, the introduction of a payment system based on diagnosis-related groups makes it necessary to install basic quality management systems within the next few years. This paper presents some well-established procedures, especially the diagnosis-related study in the whole district of Westphalia-Lippe. The aim of the study was a quality assessment of the treatment of intracapsular fractures of the collum of the femur. Problems in data analysis and interpretation are shown. Because of some grave problems, certain changes in the study design seem to be warranted. Despite these facts, however, we are convinced that we not only need this kind of quality assessment, but that we should try to expand these studies based on the experiences we gained.

An (CA)n dinucleotide repeat polymorphism of the interleukin-6 (IL-6) gene is associated with metacarpal bone mineral density in hemodialysis patients.

Genetic factors may play an important role in the pathogenesis of reduced bone mineral density (BMD). IL-6 is a multifunctional cytokine and a candidate gene for regulation of bone mineral density (BMD). The relationship between a microsatellite polymorphism of the IL-6 gene and metacarpal BMD in Japanese hemodialysis patients was examined. We selected 165 patients (96 males and 69 females) with a mean age of 62.0 +/- 13.7 years (mean +/- standard deviation (SD) in this study. They were dialyzed for an average of 75.8 +/- 60.8 months (mean +/- SD). The microsatellite polymorphism in the IL-6 gene was examined. According to the number of cytosine-adenine repeats, varying from 13 to 18, 6 alleles could be distinguished. Patients were categorized based on the presence or absence of the allele with 126 bp (i.e. 14 CA repeats) (allele A, all others allele O). The frequencies of IL-6 gene genotypes in hemodialysis patients were 16.4% for OO, 52.1% for AO and 31.5% for AA. The BMD score adjusted for age and body weight (Z score) in the AA genotype group (-0.93 +/- 1.17) was significantly lower than that in the OO (-0.09 +/- 1.42, mean +/- SD, p < 0.005) or AO group (-0.48 +/- 1.15, mean +/- SD, p < 0.01). Serum intact PTH in the OO genotype group (79.3 +/- 84.6) was lower than that in the AA (120.8 +/- 113.6, mean +/- SD, p 0.10) or AO group (132.1 +/- 106.5, mean +/- SD, p < 0.05). These results suggest that polymorphism of the IL-6 gene may be a useful marker for reduced BMD.

Prospects for bone fixation—development of new cerclage fixation techniques

The principles for the fixation and treatment of bone fractures have been well established based on the multidisciplinary studies performed by the Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF group). As the basis for modern internal fixation of fractures, these principles are presently supported by the majority of orthopedic surgeons. However, with recent advances in bioengineering and biomaterials, it has become necessary to reconsider these principles. We focused our attention on cerclage fixation, which is not considered so important by the AO group, and developed two new cerclage materials. One is a nylon strap that is in wide industrial use. In the field of orthopedics, Partridge first employed the nylon strap for internal fixation and demonstrated its efficacy in 1976. However, its use was thereafter discontinued because of various complications. We developed a nylon strap for temporary fracture fixation and demonstrated its efficacy in clinical studies. We also developed a bioabsorbable thread for the tight tying of bones. Bone fixation with a thread is sometimes used clinically, but adequate fixation often cannot be obtained because of loosening of the knot. Therefore, we prepared a blended thread by mixing poly- l-lactic acid (PLLA) and ε-polycaprolactone (PCL) fiber, so that it could be fixed tightly by melting. The fatigue strength of this thread was higher than that of a stainless-steel wire with the same cross-sectional area. We are aiming to establish more effective and convenient methods of treatment by developing new bone fixation materials and examining their efficacy. In the future treatment of fractures, it will be important to develop new instruments and bone fixation materials for the purpose of standardizing the procedures used by surgeons.