Disentangling Thermal from Electronic Contributions in the Spectral Response of Photoexcited Perovskite Materials

Disentangling electronic and thermal effects in photoexcited perovskite materials is crucial for photovoltaic and optoelectronic applications but remains a challenge due to their intertwined nature in both the time and energy domains. In this study, we employed temperature-dependent variable-angle spectroscopic ellipsometry, density functional theory calculations, and broadband transient absorption spectroscopy spanning the visible to mid-to-deep-ultraviolet (UV) ranges on MAPbBr3 thin films. The use of deep-UV detection opens a new spectral window that enables the exploration of high-energy excitations at various symmetry points within the Brillouin zone, facilitating an understanding of the ultrafast responses of the UV bands and the underlying mechanisms governing them. Our investigation reveals that the photoinduced spectral features remarkably resemble those generated by pure lattice heating, and we disentangle the relative thermal and electronic contributions and their evolutions at different delay times using combinations of decay-associated spectra and temperature-induced differential absorption. The results demonstrate that the photoinduced transients possess a significant thermal origin and cannot be attributed solely to electronic effects. Following photoexcitation, as carriers (electrons and holes) transfer their energy to the lattice, the thermal contribution increases from ∼15% at 1 ps to ∼55% at 500 ps and subsequently decreases to ∼35-50% at 1 ns. These findings elucidate the intricate energy exchange between charge carriers and the lattice in photoexcited perovskite materials and provide insights into the limited utilization efficiency of photogenerated charge carriers.

Cooling dynamics of electrons in MAPbBr3 probed in the deep-UV

Transient absorption in the Visible and in the deep-UV is performed on MAPbBr3 thin films with 3.1 eV pump excitation. The UV probe can access higher order transitions in the material exploring different high-symmetry points of the Brillouin zone. Uncorrelated electron-hole pairs are generated within the instrument response function of 150 fs. The photobleaching at 3.3 eV shows that electron cooling happens in ~ 1 ps.

Effects of mulberry leaves on production performance and the potential modulation of antioxidative status in laying hens

This study evaluated the antioxidant ability of Taisung No. 3 mulberry leaf extract (MLE) as well as the potential of mulberry leaf (ML)-based dietary supplementation for modulating the antioxidative status of laying hens. The results showed that the MLE had a total phenolic compound content of 7.4 ± 0.15 mg of gallic acid equivalent/g dry weight (DW) and a total flavonoid content of 4.4 ± 0.19 mg of quercetin equivalent/g DW. The 2, 2-diphenyl-1-picrylhydrazyl free-radical-scavenging ability was 45.9% when 0.1 mg/mL MLE was added. The lipid oxidation inhibition ability was 43.9% when 50 mg/mL MLE was added. We subjected 96 laying hens (Hendrix Genetics) to 4 treatments, namely diets supplemented with dry ML at 0 (control), 0.5, 1, or 2% for 12 weeks. Each treatment involved 8 replicates with 3 hens each. The results indicated that the 0.5% ML-supplemented group exhibited significantly higher mRNA levels of antioxidant-regulated genes, such as Nrf2, HO-1, and GST, and significantly lower ROMO1 gene expression levels at wk 12. The serum malondialdehyde level was lower and the catalase activity and superoxide dismutase activity were higher in all the ML-supplemented groups than in the control group. The egg mass and feed conversion rate significantly improved in the ML-supplemented groups compared with the control group, and, overall, 1% ML supplementation had the most favorable effects at one to 12 weeks. The egg yolk weight, shell weight, shell strength, shell thickness, yolk color, and Haugh unit were increased among all ML-supplemented groups at one to 12 weeks. On the basis of these observations, we conclude that 0.5% ML can be used as a new feed additive to potentially modulate the antioxidative status of laying hens and improve their production performance and egg quality.

How does graphene grow on complex 3D morphologies?

The growth of two-dimensional materials into three-dimensional geometries holds the promise for high performance hybrid materials and novel architectures. The synthesis of such structures, however, proceeds in fundamentally different flow regimes compared to conventional CVD where pressure differences and wall collisions are neglected. We here demonstrate the remarkable stability of graphene growth under varying fluid dynamic flow regimes. We investigate the growth process across different flow conditions using confined growth in refractory pores. Analysis of the growth rate reveals a transport-limited process which allows experimental determination of the gas diffusion coefficient. The diffusion coefficient was found to be constant for large pore dimension but scales with pore dimension as the pore size decreases below the mean free path providing clear evidence for previously predicted Knudsen molecular-flow conditions for atomic confinement. Surprisingly, changes to the flow conditions by two orders of magnitude do not cause qualitative changes of the graphene growth process. This unique behavior was attributed to rarefied flow conditions by scaling analysis and an analytical relation between growth rate and constriction could be extracted that proves accurate throughout the investigated conditions. Our results demonstrate a fundamentally different growth process compared to traditional CVD processes that is akin to atomic layer deposition and highlight the feasibility of high-quality 2D-material growth on 3D morphologies with ultra-high aspect ratios.

ApoE4 allele is associated with late-life depression: a population-based study

OBJECTIVE

This study aimed to clarify the relationship between the epsilon4 allele and late-life depression, taking into account lipid profile, vascular diseases, and sociodemographics.

METHODS

Using a multilevel stratified random sampling strategy, a total of 500 subjects aged 65 to 74 years were recruited for this cross-sectional study from the official household records of an entire county in southern Taiwan. Depressive symptoms were assessed by the Taiwanese Depression Questionnaire (TDQ). Cognitive function was assessed by the Short Portable Mental Status Questionnaire. Blood samples were collected for the determination of the apolipoprotein E (ApoE) polymorphism and the lipid profile.

RESULTS

A total of 283 subjects (58.7% male, with a mean age of 69.2 +/- 2.7 years) completed all questionnaires and collection of blood samples. Using the chi(2) test, the overall difference for frequency of the presence of the epsilon4 allele was significant among the severe group (TDQ score >18), moderate group (TDQ score 9-18), and mild group (TDQ score <9). The proportion of history of heart disease was significantly higher in the severe group than in the mild or moderate group. Kruskal-Wallis statistics revealed that the mean total and low-density lipoprotein cholesterol levels were significantly higher in the severe group than in the moderate or mild group. With our two-level four-class latent class regression model, the presence of the epsilon4 allele was significantly associated with the severely depressed group as compared to the nondepressed group, adjusting for vascular diseases and lipid profile.

CONCLUSION

The ApoE epsilon4 allele may be correlated with severe depression in the elderly through ways other than the "vascular depression" hypothesis.

The development and application of the telemedicine system in psychiatric counseling

Telemedicine are the application and development of the telecommunication networks. In this study, we try to develop the telemedicine system and to discuss the network application of this system in psychiatric counseling. The preliminary result of this study is that the telemedicine system is more effective than traditional consultation and it can provide teleconsultation service for clients with depression through the internet.

Suicidal ideation and associated factors among community-dwelling elders in Taiwan

The purpose of the present study was to explore the suicidal ideation of community-dwelling elderly and the factors associated with their intention to commit suicide. Using a multilevel stratified sampling strategy, 1000 elderly subjects were recruited (aged 65-74 years old) in Taiwan during the year 2001. The degree of depression and its correlates were assessed. Suicidal ideation was measured by asking respondents if they had had any suicidal thoughts in the previous week. In all, 16.7% of respondents reported suicidal ideation within the past week; its occurrence was related to sex, religious belief, employment status, marital status, average family monthly income, physical health status, depressive symptoms, and community activity participation. Further multivariate logistic regression revealed that, aside from depressive symptoms and a lower level of education, no community participation in the past 6 months was significantly associated with the appearance of suicidal ideation. The prevalence of suicidal ideation among the elderly in Taiwan is higher than in Western countries. Participation in social activities is negatively associated with elderly suicidal ideation. The dimension of social participation deserves further exploration and should be considered in community mental health promotion interventions for elderly people.

Religious attendance and depressive symptoms among community dwelling elderly in Taiwan

BACKGROUND

The purpose of this study was to investigate the unique association between religious attendance and the prevalence of depressive symptoms among community dwelling elderly persons.

METHODS

Employing a multilevel stratified sampling strategy, a total of 1000 subjects, aged 65-74 and living in Taiwan, were recruited for this interview survey during the year 2001. Aside from background information, the Taiwanese Depression Questionnaire (TDQ) and the Neighborhood Quality Index were used to assess degree of depression and its correlates.

RESULTS

Altogether, 863 subjects (age, M = 69.4, SD = 2.7) had complete data for analysis; 215 (24.8%) had had depressive symptoms in the past week. Among them, those who were female, (OR = 2.17, 95% CI = 1.59-2.97), illiterate(OR = 2.42, 95% CI = 1.76-3.33), unemployed (OR = 1.80, 95% CI = 1.24-2.61), or not married (OR = 1.71, 95% CI = 1.22-2.38), or those who had less family income (OR = 1.84, 95% CI = 1.24-2.73), physical illness (OR = 2.68, 95% CI = 1.86-3.86), or less social capital (OR = 0.91, 95% CI = 0.88-0.94), were at higher risk of being depressed. Moreover, those (95.2% with religious belief ) who had not attended religious activities during the past 6 months were at higher risk of being depressed than those (100% with religious belief ) who had (OR = 2.63, 95% CI = 1.41-4.91). Multivariate logistic regression disclosed that those never attending religious activities were 2.70 times more likely to be depressed when compared to those who had, after taking into consideration sociodemographics and social capital.

CONCLUSION

The attending of religious activities is a protective factor for geriatric depression.

Cognitive impairment and associated risk factors among aged community members

OBJECTIVE

The objective of this paper is to investigate the prevalence of and risk factors associated with cognitive impairment in a community-dwelling elderly population.

METHODS

1000 community residents aged 65-74 years were recruited in the cross-sectional survey of associated factors of cognitive impairment in southern Taiwan. We employed a multilevel stratified sampling strategy and conducted this interview survey from April to June 2001. The survey questionnaire included background information and the Short Portable Mental Status Questionnaire. The relationship between cognitive impairment and each individual variable in personal attributes and social participation were explored.

RESULTS

Eight hundred and ninety-four (89.4%) subjects completed the interview and questionnaires. The cognitive impairment rate among all subjects was 4.92%. Of those surveyed, 54.98% were male and 45.02% were female, and the average age was 69.37 (SD 2.73) years. Most survey respondents (72.05%) were married, and 68.90% of the subjects did not participate in any social activities in the last 6 months. Females, those who were illiterate or did not attend school, those who had an average family income below US$860 per month, and persons who did not participate in any social activities had a significantly higher rate of cognitive impairment.

CONCLUSION

The educational level and participation in social activities were associated with the cognitive impairment among the aged community dwellers.

Hip arthroplasty in patients with cirrhosis of the liver

We retrospectively reviewed 45 hip arthroplasties which were performed over a period of 20 years in 38 patients with cirrhosis of the liver. There was a high perioperative 30-day complication rate (26.7%). Advanced cirrhosis was associated with a higher risk of complications (p = 0.004) as also was increased age, a high level of creatinine, a low level of albumin, a low platelet count, ascites, encephalopathy and an increased operative blood loss. The survival of the prosthesis at five years was 77.8% and infection was a major cause of failure. In view of the high rate of early complications and the limited longevity of the prosthesis, surgeons who perform hip arthroplasty on such patients should counsel them appropriately preoperatively.

Effects of Tamm-Horsfall protein and albumin on calcium oxalate crystallization and importance of sialic acids

BACKGROUND

Tamm-Horsfall protein and human serum albumin are common urinary proteins that show uncertain inhibitory action on the crystallization of calcium oxalate monohydrate.

MATERIALS AND METHODS

Batch experiments on crystal nucleation, growth, and aggregation were performed using purified Tamm-Horsfall protein and albumin before and after enzymatic removal of sialic acids from the proteins.

RESULTS

At a concentration of 100 nM, both Tamm-Horsfall protein and albumin promoted the time of crystal nucleation by 18.4% and 8.9%, respectively, relative to the control. However, both of the proteins exerted an inhibitory effect on crystal growth, with the IC(50) being 7.27 nM for Tamm-Horsfall protein and 37.5 nM for albumin. The inhibition of crystal aggregation was 81.82% by Tamm-Horsfall protein 100 nM but only 54.55% at 50 nM after enzymatic removal of the sialic acid. Instead of increasing the inhibition, the effect was changed to promotion after an increase in the concentration of Tamm-Horsfall protein to more than 500 nM for native protein and to more than 100 nM for the enzymatic digest. Albumin showed little change after enzymatic treatment and maintained a maximal inhibitory effect of 72.73% on crystal aggregation when the concentration reached to 100 nM.

CONCLUSION

Because the promotion of nucleation could lessen the subsequent saturation of a calcium oxalate solution, it is concluded that Tamm-Horsfall protein and albumin show an overall effect of inhibition on crystallization in vitro. The inhibitory effect of Tamm-Horsfall protein is partly related to sialic acid.

Hepatitis C virus infection among teenagers in an endemic township in Taiwan: epidemiological and clinical follow-up studies

The aim of the study was to elucidate the epidemiological features of Hepatitis C virus (HCV) infection among teenagers in an endemic area by conducting a mass screening study. We also investigated the clinical outcome of the anti-HCV-positive subjects by conducting subsequent short-term and long-term follow-up studies. All 2837 students of two junior middle schools in Tzukuan, aged 13-16 years, were invited to be screened for anti-HCV, HBsAg, AST and ALT in October 1995. A total of 2726 (96%) students responded. Anti-HCV, HCV RNA and aminotransferase levels were evaluated among anti-HCV-positive students 1 month and 30 months later, respectively. A total of 38 (1.4%; M/F = 22/16) participants were anti-HCV-positive. The anti-HCV-positive students had higher rates of exposures to transfusion, anti-HCV-positive families and surgery. The prevalence (2.8%) of the 7 maritime villages was markedly higher than that (0.7%) of the other 8 villages (P < 0.001). Subsequent follow-up studies demonstrated that there might be 5 cases of acute or recent HCV infection, and 6 cases who had recovered from chronic HCV infection.

Signal transduction pathways and apoptosis in bacteria infected chondrocytes

The mechanism underlying chronic destructive arthropathy after pyogenic arthritis is not clear. This study evaluated the role of apoptosis in Staphylococcus aureus infected human articular chondrocytes and investigated the signal transduction pathways activated by bacterial infection. Chondrocytes cultured in monolayer were challenged with bacteria for 6 h and were analyzed after incubation for 2, 18, and 24 h. Chondrocytes showed morphologic and biochemical evidences of apoptosis after infection and the following incubation period. Although treatment with extensive washing and vancomycin could ameliorate the amount of apoptosis from 31% to 15% at 2 h, from 48% to 23% at 18 h, and from 58% to 33% at 24 h, the infected samples with treatment still had higher amount of apoptosis than the un-infected controls (ANOVA P < 0.001). Accompanying with the increasing amount of apoptosis, the caspase activity was upregulated in bacteria infected samples and remained high in samples with treatment (ANOVA P < 0.05). Signal transduction pathways activated by bacterial infection were assessed by co-transfection technique. After infection, the c-Jun N-terminal kinase, extracellular signal-regulated kinase, and cyclic AMP-dependent protein kinase activities were elevated by 7.6-, 7.3-, and 3.2-fold, respectively, compared to the uninfected controls. The data support the hypothesis that human chondrocytes will undergo apoptosis after infection by a single organism. Apoptosis and activated intracellular kinase activities may be related to the pathogenesis of post-infectious destructive arthropathy.

Destructive spondyloarthropathy mimicking spondylitis in long-term hemodialysis patients

A 63-year-old man with end-stage renal disease (ESRD) who had been undergoing hemodialysis for 18 years suffered persistent neck pain, progressive quadriparesis, and a deteriorating ataxic gait during the 6 months before admission. A sudden onset of aggravating quadriparesis and an inability to ambulate occurred during his trip to Sydney, Australia, 1 week before this admission. Vertebral tuberculosis osteomyelitis of the C5/6 segment was considered and treated in a hospital there. Findings from cervical magnetic resonance imaging (MRI; low signal intensity on both T1- and T2-weighted images) were diagnostic of destructive spondyloarthropathy (DSA) and distinguishable from spinal osteomyelitis preoperatively. Amyloid masses, mainly composed of B-2 microglobulin, filled in disc and paradiscal ligaments, with adjacent end-plate destruction by cytokine-mediated reactive inflammation, and appeared to be mostly related to the pathogenesis of DSA. The cervical spine, especially C5/6, is the most common site of DSA. Spinal instability and neurologic compression cause the clinical symptoms and signs. Adequate decompression and successful cervical fusion ensure the best therapeutic results.

Primary cultures of human chondrocytes are susceptible to low inocula of Staphylococcus aureus infection and undergo apoptosis

Hypocellularity after joint infection has been attributed to the cytotoxic effects of pus, which can cause necrosis of chondrocytes. In this study, primary cultures of human chondrocytes lost their viability and underwent necrosis rapidly with high inocula of Staphylococcus aureus infection. Chondrocytes were shown to undergo apoptosis with low inocula of Staphylococcus aureus or their culture ultrafiltrate. These findings further support the hypothesis that residual bacterial toxins or triggered apoptotic processes in chondrocytes participate in the pathogenesis of post-infectious arthropathy.

Lateral collateral ligament reconstruction using quadriceps tendon-patellar bone autograft with bioscrew fixation

The lateral collateral ligament is the primary stabilizer against varus stress and is also an important contributor in maintaining posterolateral knee stability. Quadriceps tendon-patellar bone autograft has been used for anterior or posterior cruciate ligament reconstruction. We introduce a reconstructive procedure to restore the lateral collateral ligament using a quadriceps tendon-patellar bone autograft. The procedure is designed for unstable knees with concomitant cruciate ligament tear and posterolateral complex injury. This is a reasonable choice especially when allograft tissue is not available or in patients who are not suited for the use of bone-patellar tendon-bone autograft.

Surgical treatment for pathological long bone fracture in patients with multiple myeloma: a retrospective analysis of 22 cases

BACKGROUND

The purpose of this study was to retrospectively review the cases of pathologic long bone fractures caused by multiple myeloma treated in our hospital, to analyze the surgical method, complications, radiation therapy, survival time, and influence on quality of life.

METHODS

In a retrospective study, 22 patients with the pathological long bone fractures due to multiple myeloma who were surgically treated between 1987 and 1997 were analyzed. All patients received open reduction and internal fixation either with plates or intra-medullary nailing. Cement augmentations were performed in the majority of cases (91%). A detailed retrospective analysis was done to correlate the surgical methods, radiation therapy, functional results, and complications post-surgically.

RESULTS

The most common site of fracture was the femur. The mean postoperative survival time was around 19 months. Post-operative pain relief was satisfactory, and only two patients required narcotics. No major complications were observed. However the union rate was only 30%, which might have been due to the inhibitory effect of radiation therapy on bone healing, or insufficient osteogentic ability of the myeloma-involved bone.

CONCLUSION

Satisfactory pain relief and low implant failure rate was achieved and no definite evidence of tumor dissemination was found in this study. The authors suggest that open reduction and internal fixation with cement augmentation is a favorable treatment option for those patients suitable for surgery. However, postoperative radiation therapy may be associated with a low rate of union.

Tension-band technique for ankle fusion

A prospective study was conducted to develop a better technique for ankle fusion. Eleven consecutive patients were treated using the tension-band technique for ankle fusion and underwent follow-up for a minimum of 2 years (range: 2-5 years). All 11 patients achieved solid fusion for a fusion rate of 100%. Average time to fusion was 3 months (range: 2-6 months). The indication for ankle fusion was intractable aching pain that could not be controlled by conservative methods. Two of 11 patients underwent surgery due to infected arthritis. After ankle fusion, there was no recurrence of infection during a 3-year follow-up period. The technique included osteotomy of the bimalleoli from the inside out, removal of articular cartilage and preserving wedge space for cancellous bone grafting, with or without staple stabilization, and external immobilization supplementation. The functional outcome in all 11 patients improved from unsatisfactory preoperatively to satisfactory at latest follow-up (P<.001). No significant complications were noted. This simple technique proved excellent for ankle fusion with a satisfactory outcome and is recommended for treating severe ankle arthropathies.

Arthroscopic double-bundled posterior cruciate ligament reconstruction with quadriceps tendon-patellar bone autograft

An arthroscopic technique for double-bundled reconstruction for posterior cruciate ligament with quadriceps tendon-patellar bone autograft is presented. Anterolateral and posteromedial tunnels were created to simulate and reproduce the double-bundle structure of the posterior cruciate ligament. The bone plug is situated at the tibial tunnel and fixed by a titanium interference screw. Each of the bundles of tendon graft is rigidly fixed at the femoral tunnel with a bioabsorbable screw.

Bipolar versus total hip arthroplasty for hip osteonecrosis in the same patient

The authors studied 28 patients with bilateral avascular necrosis of the femoral head who were treated with a cementless bipolar endoprosthesis in one hip and cementless total hip arthroplasty in the other. All the hips selected for bipolar endoprostheses were classified as having avascular necrosis of the femoral head Ficat Stage III, and all the hips selected for total hip arthroplasty were classified as having Ficat Stage IV avascular necrosis. After a midterm followup of an average of 6.4 years (range, 4-12 years), 24 of 28 hips that received bipolar endoprostheses were considered satisfactory, whereas 23 of 28 hips in which an arthroplasty was done were considered satisfactory. After a followup of more than 6 years, the cartilaginous space of the acetabulum could be preserved in 25 hips (89.3%) that received a bipolar endoprosthesis. There were no statistical differences in both groups in terms of clinical result, thigh pain, groin pain, osteolysis, dislocation, and revision rate. Total hip arthroplasty is not the preferred treatment for all patients with hip osteonecrosis. In young patients with Ficat Stage III osteonecrosis with Grade 0 or Grade I cartilage, the use of a cementless bipolar endoprosthesis with a bone ingrowth stem may be considered as an alternative to total hip arthroplasty.

Treatment of deltoid contracture in adults by distal release of the deltoid

Twenty-five consecutive adult patients (32 shoulders) with deltoid contracture were treated with distal release and followed up for an average of 4 years (range, 2-8 years). All shoulders achieved full range of motion and complete relief of pain and deformity after 3 months. No muscle weakness was clinically evident. In addition, another five adult patients (nine shoulders) with deltoid contracture were treated with distal release and quantitative measurement of muscle power recovery around the shoulder with Cybex 340 dynamometer before surgery, and 3 months and 1 year after surgery. Isokinetic peak torque of shoulder muscles did not decrease significantly at either 60 degrees per second or 180 degrees per second angular velocity after surgery. In addition, the shoulder extensors showed a twofold increase of isokinetic peak torque after surgical release of deltoid contracture. Distal release was a simple and effective surgical technique to treat deltoid contracture in adults. All patients in this series achieved a satisfactory outcome.

Mechanical properties of acrylic bone cement containing PMMA-SiO2 hybrid sol-gel material

An organic-inorganic hybrid material, poly(methyl methacrylate) (PMMA)-SiO2 (SiO2 content of 72 wt%), was prepared by incorporating PMMA structure units covalently into an SiO2 glass network via the sol-gel approach. The hybrid sol-gel material PMMA-SiO2 was subsequently used as the solid powder component of bone cement and its mechanical properties were evaluated. The effects of the addition of tricalcium phosphate (TCP), hydroxyethyl methacrylate (HEMA), and ethylene glycol dimethacrylate (EGDMA) on the properties of the sol-gel hybrid bone cement were also investigated. The influence of these components on the temperature rise during polymerization was discussed. It was found that the new bone cement containing PMMA-SiO2 hybrid sol-gel material had higher modulus than that of Simplex-P bone cement. The addition of TCP in the new bone cement increased the Young's modulus and the polymerization time; the inverse was observed for the tensile, bending, and compressive strengths, and the polymerization temperature. The addition of HEMA and EGDMA in the new bone cement had the opposite effect of TCP. The comparison between the new sol-gel bone cement and the commercial Simplex P bone cement was discussed.

Characterization of acrylic bone cement using dynamic mechanical analysis

Dynamic mechanical analysis (DMA) was used to characterize the properties of acrylic bone cement with the addition of tricalcium phosphate (TCP), hydroxyethyl methacrylate (HEMA), and ethylene glycol dimethacrylate (EGDMA). The glass transition temperature of acrylic bone cement is >100 degrees C; the cement has a flat modulus response near human body temperature. The height of the damping peak decreases and becomes broader with increasing TCP content. Thus, TCP is incompatibile with acrylic bone cement. When the frequency is changed from high to low, the damping peak shifts to low temperature. The shift in damping peak with frequency indicates that this relaxation is time-dependent. When acrylic bone cement contains TCP with HEMA and EGDMA, the incompatibility between acrylic bone cement and TCP can be ameliorated.

Biomechanical comparison for different configurations of tension band wiring techniques in treating an olecranon fracture

BACKGROUND

The aim of this study was to compare the superiority between the newly designed modified AO tension band wiring technique and the traditional modified AO tension band wiring technique in treating an olecranon fracture.

METHODS

Eight pairs of fresh cadaveric ulnae were tested biomechanically. After transverse osteotomy of the olecranon, all left ulnae were fixed by the traditional modified AO technique with two Kirschner wires inserted through the anterior ulnar cortex and all right ulnae by the new technique with two Kirschner wires inserted into the marrow cavity from the olecranon to the ulnar styloid process. All specimens were tested by the Material Testing System machine to evaluate fragment displacement and the maximal failure load. A dual linear variable displacement transducer was used to measure relative minimal displacement.

RESULTS

There was no significant difference between the techniques. The maximal failure load by either technique was more than 80 kg. Even at testing failure, no Kirschner wires migrated proximally.

CONCLUSION

The new technique may be applied widely to treat all olecranon fractures, because it is a technically easier and safer technique. Less than 5.5-kg loads could be permitted in daily activity postoperatively. A single tolerable loading weight should not exceed 8 kg. Kirschner wires will not migrate proximally, despite increased joint loading. Clinically, this study may confirm indirectly the hypothesis that proximal migration of Kirschner wires was mainly due to triceps traction.

Tibial shaft malunion treated with reamed intramedullary nailing: a revised technique

Thirty-seven consecutive adult tibial shaft malunions which had not undergone surgical treatment were prospectively treated with reamed intramedullary nailing. Indications for this treatment modality included a malunion of a tibial shaft which had only been conservatively treated, lesion level fitting for traditional or locked reamed intramedullary nail fixation, less than 2 cm shortening, and without evidence of deep infection at present. The malunions were treated with fibulotomy, closed wedge tibial osteotomy, open reaming of the marrow cavity, stable reamed intramedullary nail stabilization with or without supplementation, and cancellous bone grafting. Thirty-four (92%) patients were followed up for at least 1 year (range 1.0-4.3 years), and all achieved a solid union. The union period was 5.8+/-0.8 months. Complications included 2 (6%) patients with deep infection and 1 (3%) with cortical perforation. However, all 3 patients recovered completely after adequate management. In conclusion, a reamed intramedullary nail is an ideal instrument for tibial shaft malunions in indicated cases. Good exposure of the bony segments to ream the marrow cavity precisely can avoid cortical perforation. Gentle dissection of the soft tissues may lower the infection rate. Concomitant cancellous bone grafting can improve the union rate.

Vascular endothelial growth factor expression predicts outcome and lymph node metastasis in squamous cell carcinoma of the esophagus

Vascular endothelial growth factor (VEGF) expression and tumor microvessel density (MVD) were examined by immunohistochemical staining in 117 cases of thoracic esophageal squamous cell carcinoma. Thirty-six (31%) of the 117 cases were evaluated as VEGF-positive. The average number of metastatic lymph nodes at surgery was 5.6 in the VEGF-positive cases and 3.0 in the VEGF-negative cases and was significantly higher in those with VEGF-positive cases (P = 0.04). The incidence of pathological tumor (PT)2-4 cases among the high-MVD cases was significantly higher than among the low-MVD cases (P = 0.01). MVD was 59.4 +/- 4.7 (mean +/- SE)/mm2 in the VEGF-positive cases and 47.9 +/- 3.8/mm2 in the VEGF-negative cases. The MVD of the VEGF-positive tumors was higher than that of VEGF-negative tumors, but the difference was not significant (P = 0.08). The survival rate of the patients with high-MVD tumors was significantly poorer than those with low-MVD tumors, and the survival rate of those patients with VEGF-positive tumors was significantly poorer than in those with VEGF-negative tumors (P = 0.009 and P = 0.04, respectively). The cumulative survival rates in the VEGF-positive groups were found to be significantly poorer in the pT3 and pathological node (pN)1 groups when stratified according to pT factor (pathological T category) and pN factor (pathological N category) in the tumor-node-metastasis (TNM) classification. VEGF expression had the second highest hazard ratio in the multivariate analysis, after pN factor. These results indicate that VEGF is a useful marker for predicting the outcome in patients with more advanced esophageal squamous cell carcinoma. It seems that TNM factors and VEGF expression are important factors in the selection of appropriate treatments.

MicroStructured Omnifit acetabular components: concerns with locking system complications and excessive polyethylene wear

BACKGROUND

We began to use cementless MicroStructured Omnifit acetabular components in November 1988. Liner dislodging and excessive polyethylene wear later occurred in some of our patients. This finding prompted us to review our experience with the use of such modular acetabular components.

METHODS

A total of 887 hips in 672 patients, which had been fitted with cementless MicroStructured Omnifit acetabular components, were evaluated for locking system complications using radiographic examinations. Of the cases, 240 hips which had received a 26-mm femoral head (group 1) and 110 hips which had received a 32-mm femoral head (group 2) were compared using a digitiser to determine the influence of femoral head size on polyethylene wear.

RESULTS

There were two types of radiographic signs of locking system complications in 7 hips, at a mean time of 2.9 years after implantation. The incidence of liner locking system complications using this modular acetabular component was 0.8%. The mean liner wear rate per year was 0.15 mm in group 1 and 0.20 mm in group 2 (p <0.005). The initial polyethylene thickness ranged from 5.9 to 13.6 mm in group 1, compared with 3.9 to 10.6 mm in group 2 (p < 0.005).

CONCLUSION

A patient who has received a total hip arthroplasty that includes a MicroStructured Omnifit acetabular component should be monitored frequently for radiographic signs of locking system complications. In this study, the mean liner wear rate was significantly higher in group 2. Inadequate polyethylene thickness in this group was implicated as the major cause of excessive polyethylene wear.

Anterior reconstructive spinal surgery with Zielke instrumentation for metastatic malignancies of the spine

From March 1984 to April 1996, 60 consecutive patients with spinal metastasis underwent palliative surgery by anterior corpectomy and Zielke instrumentation. Their ages ranged from 21 to 76 years (mean 54 years). Thirty-two patients had metastasis to the thoracic spine, 20 to the lumbar spine, and 8 had both thoracic and lumbar metastases. The primary malignancies were lung cancer in 12 patients, colorectal cancer in 10, hepatoma in 9, thyroid cancer in 7, breast cancer in 3, and cancers of the stomach, kidney, nasopharynx, long bones, skin, and cervix in 1 patient each. A primary carcinoma was never identified in 13 patients. In the present series, 4 patients died within 1 month, and 56 patients were followed-up. All maintained spinal stability postoperatively. Forty of 52 patients with severe pain obtained significant symptomatic relief for 3 months or more, and 33 of the 46 paralyzed patients gained neural improvement. Sphincter dysfunction became better in 10 patients, and none became worse. We conclude that anterior corpectomy to decompress neural encroachment with instrumental reconstruction to stabilize the collapsed spine is a good adjunctive treatment in these highly selected patients.

Complications of liner locking system in Micro-structured Omnifit acetabular components: a radiographic evaluation of 887 hips followed for 5-10 years

We evaluated 887 hips in 672 patients with uncemented MicroStructured Omnifit acetabular components for liner locking complications. We found 2 types of radiographic signs of liner locking system complications in 7 hips, developing between 2 and 4 years postoperatively. The incidence of liner locking system complications was 0.8% using this modular acetabular component. We recommend that a patient who has received a total hip arthroplasty including a MicroStructured Omnifit acetabular component should be monitored frequently for radiographic signs of liner locking system complications, especially with a polyethylene thickness of less than 8 mm.

Early polyethylene wear and osteolysis in cementless total hip arthroplasty: the influence of femoral head size and polyethylene thickness

We examined initial polyethylene thickness, early polyethylene liner wear, and osteolysis in 350 primary, cementless total hip arthroplasties (THAs). All of the prostheses were of identical design and used Omnifit components. In the 32-mm head group, the mean liner wear correlated significantly with polyethylene thickness (P<.001) and increased rapidly with initial thinner polyethylene following a logarithmic model, although this increase was not statistically significant (r = -.633). Inadequate polyethylene thickness in the 32-mm head group was implicated as the major cause of higher liner wear. A minimal polyethylene thickness of 7 mm is recommended in cementless metal-backed THAs. The use of a large head combined with poor prosthetic design appeared to be responsible for the unacceptably high incidence of femoral osteolysis.

Hyperbaric oxygen therapy mitigates the adverse effect of cigarette smoking on the bone healing of tibial lengthening: an experimental study on rabbits

OBJECT

We investigated whether -intermittent hyperbaric oxygen (HBO) therapy can mitigate the adverse effects of cigarette smoking on the bone healing of tibial lengthening by using a previously validated rabbit model.

METHODS

Eighteen male rabbits were randomly divided into three groups of six animals each. Group 1 (smoking plus HBO) went through intermittent cigarette smoke inhalation and hyperbaric oxygen therapy, group 2 (control) did not go through intermittent cigarette smoke inhalation or hyperbaric oxygen therapy and group 3 (smoking) went through intermittent cigarette smoke inhalation. Each animal's right tibia was lengthened 5 mm by using an uniplanar lengthening device. Bone mineral density (BMD) study was performed for all the animals at 1 day before operation and 3, 4, 5, and 6 weeks after operation. All of the animals were killed at 6 weeks postoperatively for biomechanical testing.

RESULTS

By using the preoperative BMD as an internal control, we found that the BMD of group 1 (smoking plus HBO)and group 2 (control) was superior to that of group 3 (smoking). The mean %BMD at 3, 4, 5, and 6 weeks were 58.6%, 66.6%, 73.7%, and 83.8%, respectively, in group 1, whereas the mean %BMD were 52.0%, 64.3%, 70.1%, and 76.2%, respectively, in group 2, and the mean %BMD were 46.2%, 54.0%, 64.9%, and 69.4%, respectively, in group 3 (two-tailed t test, p > 0.05, p > 0.05, p > 0.05, and p < 0.05 at 3, 4, 5, and 6 week respectively between group 1 and group 2, p < 0.01,p < 0.01,p < 0.01, and p < 0.01 at 3, 4, 5, and 6 week, respectively, between group 1 and group 3 and p < 0.05, p < 0.05, p < 0.05, and p < 0.05 at 3, 4, 5, and 6 week respectively between group 2 and group 3). By using the contralateral nonoperated tibia as an internal control, we found that the torsional strength of group 1 (smoking plus HBO) and group 2 (control) was superior to that of group 3 (smoking). The mean percentage of maximum torque was 80.9% in group 1 (smoking plus HBO) and was 78.0% in group 2 (control), whereas the mean percentage of maximum torque was 59.6 % in group 3 (smoking) (two-tailed t test, p < 0.05 between groups land 3 and between groups 2 and 3, whereas p > 0.05 between groups 1 and 2).

CONCLUSION

This study suggests that smoke inhalation delays the bone healing in tibial lengthening; however, HBO mitigates the delayed healing effect of smoke inhalation and, thus, helps the smoking animal in achieving an expeditious bone healing in tibial lengthening.

Treatment of ununited femoral shaft fractures associated with locked nail breakage: comparison between closed and open revision techniques

OBJECTIVES

To investigate and compare closed and open revision techniques in the treatment of ununited femoral shaft fractures associated with locked nail breakage.

DESIGN

Retrospective.

SETTING

University hospital.

METHODS

Ununited femoral shaft fractures associated with locked nail breakage were treated with either closed or open revision (nine or eighteen cases, respectively). The closed technique entailed closed removal of the broken nail and reinsertion of a stable intramedullary nail after reaming the marrow cavity. The open technique included open removal of the broken nail, reinsertion of a stable intramedullary nail or plate, and cancellous bone graft supplementation. Union rate, union period, perioperative course, and complications were compared.

RESULTS

Eight closed and fifteen open technique cases were followed for at least one year (median two years). Cases treated with the closed technique had a union rate of 100 percent, a union period of 4.4+/-0.9 months, an operating time of 1.5+/-0.4 hours, no blood transfusion, and no complications. Open technique cases demonstrated a union rate of 100 percent, a union period of 5.7+/-1.5 months (p = 0.033), an operating time of 2.4+/-0.4 hours (p < 0.001), blood transfusion of 1,000+/-500 milliliters (p < 0.001), and no complications.

CONCLUSIONS

We recommend the closed revision technique because its union period and operating time are shorter, and it does not require a blood transfusion. Because there is no local wound dissection, infection rates should also be lower. However, the procedure is technically demanding. If it cannot be completed successfully, using the open technique can still achieve a satisfactory outcome.

Acute postoperative aggravation of radiculopathy as a complication of free fat transplantation in lumbar disc surgery: case report

This case report illustrates a rare case of motor weakness caused by a free fat graft herniation. A 40-year-old woman who had undergone surgery for a herniated lumbar intervertebral disc experienced right lower leg weakness. On magnetic resonance image (MRI) a herniated free fat graft was noted. An emergent operation was performed and the herniated fat graft was removed. Postoperatively, the patient recovered well with improvement of the motor weakness. MRI is a good method for diagnosis of fat graft herniation. The mechanisms of this complication have been documented, and the size of the fat graft plays an important role. The methods for prevention of this herniation are also discussed. Although the transplantation of adipose tissue has many advantages, including the prevention of postoperative epidural fibrosis, great care is needed when applying a fat graft intra-operatively. When a postoperative neurologic deficit develops, herniation of the fat graft must be considered. An emergent operation is the treatment of choice for this particular complication.

Effect of reaming bone grafting on treating femoral shaft aseptic nonunion after plating

Rigid intramdullary nailing with cancellous bone grafting provided by intramedullary reaming was prospectively used to treat femoral shaft aseptic nonunions after plating. Indications for this technique were a femoral shaft nonunion with an inserted plate, no previous infection sign in the treatment course, less than 1.5 cm shortening, and no segmental bony defects. After the plate was removed, a flexible guidewire was inserted antegradely. The local wound was closed, and intramedullary reaming was done as widely as possible until some resistance to it occurred. Finally, a rigid intramedullary nail was inserted. Twenty-four consecutive patients were treated with this regimen, and 21 were followed-up for at least 1 year (range 1-5 years). All 21 nonunions healed with a union rate of 100% (21/21). The time to union was 4.5 +/- 1.0 months. There were no significant complications. We conclude that for indicated cases, reaming bone grafting is a very effective technique and avoided donor site morbidity. Therefore, whenever possible, this technique could be considered first.

Fixation of small tibial avulsion fracture of the posterior cruciate ligament using the double bundles pull-through suture method

BACKGROUND

Avulsion of the tibial insertion of the posterior cruciate ligament is commonly repaired via open reduction and internal fixation with a screw, Kirschner's wire, and suture. In the case of a major bony fragment, this technique is adequate to achieve rigid fixation. In the case of an avulsion fracture with a small bony fragment, however, it is not uncommon to break the bone fragment during screw fixation. We describe a new technique for fixation of an avulsion fracture with a small bony fragment. The technique uses a double bundles pull-through suture technique that repairs the anterolateral and posteromedial components of the posterior cruciate ligament simultaneously.

METHODS

From March 1994 through May 1997, 12 patients with small tibial avulsion fractures of the posterior cruciate ligament were treated using this technique.

RESULTS

At an average of 18 months after surgery (range, 12-24 months), the preliminary clinical and radiographic results were satisfactory. Eleven patients could return to the same or a higher level of preinjury sports activity. According to the International Knee Documentation Committee rating system, 10 of the 12 patients had normal or nearly normal ratings.

CONCLUSION

The double bundles pull-through suture technique can avoid the risk of breakage of the small bony fragment, does not require the removal of hardware, and can achieve adequate repair in the anatomic situation. Our clinical experience suggests that it is a good choice for fixation in cases of avulsion fracture with a small bony fragment.

Development of a biodegradable antibiotic delivery system

Antibiotic beads have been used as a drug delivery system for the treatment of various surgical infections. In this study, the copolymer 50:50 poly(DL-lactide):co-glycolide was mixed with vancomycin powder and hot compressing molded at 55 degrees C to form five types of biodegradable antibiotic beads. The beads were placed in 1 mL of phosphate buffered saline and incubated at 37 degrees C. The phosphate buffered saline was changed daily, and the removed buffer solutions were stored at -70 degrees C until the antibiotic concentration in each sample was determined by high performance liquid chromatography system assay. The concentration of vancomycin in each sample was well above the breakpoint sensitivity concentration (the antibiotic concentration at the transition point between bacterial killing and resistance to the antibiotic) for more than 32 days. The release was most marked during the first 48 hours. All copolymer 50:50 poly(DI lactide):co-glycolide biodegradable beads released high concentrations of the antibiotics in vitro for the time needed to treat bone infections (4 to 6 weeks). The diameter of the sample inhibition zone ranged from 6.5 mm to 10 mm, and the relative activity of vancomycin ranged from 12.5% to 100%. Copolymers with low heat of formation temperatures are required for making a controlled release system to prevent antibiotic decomposition, which occurs when using the hot compressing molded method. The rate and duration of release from the antibiotic beads can be adjusted by varying the diameter of the beads. This offers a convenient method to adjust the release rate to meet the specific antibiotic requirements for different patients.

Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon-patellar bone autograft

BACKGROUND

Surgical reconstruction of the anterior cruciate ligament (ACL) is indicated in the ACL-deficient knee with symptomatic instability and multiple ligaments injuries. Bone patellar tendon-bone and the hamstring tendon generally have been used. In the present study, we describe an alternative graft, the quadriceps tendon-patellar bone autograft, by using arthroscopic ACL reconstruction.

METHODS

From March of 1996 through March of 1997, a quadriceps tendon-patellar bone autograft was used in 12 patients with ACL injuries.

RESULTS

After 15 to 24 months of follow-up, the clinical outcome for those patients with this graft have been encouraging. Ten patients could return to the same or a higher level of preinjury sports activity. According to the International Knee Documentation Committee rating system, 10 of the 12 patients had normal or nearly normal ratings. Recovery of quadriceps muscle strength to 80% of the normal knee was achieved in 11 patients in 1 year.

CONCLUSION

The advantages of the quadriceps tendon graft include the following: the graft is larger and stronger than the patellar tendon; morbidity of harvest technique and donor site is less than that of patellar tendon graft; there is little quadriceps inhibition after quadriceps harvest; there is quicker return to sports activities with aggressive rehabilitation. A quadriceps tendon-patellar autograft is a reasonable alternative to ACL reconstruction in patients who are not suitable for either a bone-patellar tendon-bone autograft or a hamstring tendon autograft.

Arthroscopic posterior cruciate ligament reconstruction with quadriceps tendon-patellar bone autograft

Surgical reconstruction of the posterior cruciate ligament (PCL) is indicated in the PCL-deficient knee with symptomatic instability and multiple ligamentous injury. However, the choice of graft tissues continues to be controversial. We describe an arthroscopic PCL reconstruction technique using the quadriceps tendon-patellar bone autograft. From March through September 1996, this autograft was used in 12 patients with PCL injuries. After 1-1.5 years' follow-up, the clinical outcome has been encouraging. In addition, the quadriceps tendon-patellar autograft has the advantage of being self-available. Furthermore, the technique is easy to perform and has comparable anatomic and biomechanical qualities to other available techniques. Quadriceps tendon-patellar autograft is a reasonable alternative choice for PCL reconstruction.

Congenital dislocation of the knee

Between February 1988 and June 1995, 24 congenital dislocations of the knee joints (17 patients) were reduced with closed methods including immediate reduction, serial casting, or traction in patients from 10 min to 26 days old. At an average follow-up of 4 years and 10 months, an excellent or good result was achieved if there were no associated anomalies. Fair or poor results were the result of delayed treatment or associated musculoskeletal anomalies including arthrogryposis multiplex congenita or Larsen's syndrome. Routine check of the hip dislocation is suggested. Diagnosis with manual testing was difficult, and other methods such as radiography or sonography were suggested in combination to detect hip dysplasia. The dislocated knee should be reduced before treating the hip dislocation. Concomitant treatment of the congenital dislocation of the knee and the hip with Pavlik harness provided satisfactory results. When late, progressive, genu valgus deformity occurred because of global instability of the knee and asymmetric physeal growth, reconstruction of the medial structures of the knee and prolonged bracing provided good results.

Treatment of femoral neck nonunions with a sliding compression screw: comparison with and without subtrochanteric valgus osteotomy

BACKGROUND

The aim of this prospective study was to investigate and compare the results of treatment of femoral neck nonunions using a sliding compression screw (SCS) with and without subtrochanteric valgus osteotomy (SVO).

METHODS

Thirty-two consecutive patients with femoral neck nonunions, which sustained no osteonecrosis of the femoral head based on bone scan study, were prospectively treated with SCS with (21 patients) or without (11 patients) SVO. The indication for SCS with SVO was a femoral neck nonunion with leg shortening of more than 1.5 cm. SCS without SVO was for leg shortening of less than 1.5 cm.

RESULTS

Seventeen patients with osteotomy and nine patients without osteotomy were followed for at least 2 years (range, 2-8 years). All femoral neck fractures healed, with a union period of 4.6+/-1.0 months (95% confidence interval, 4.1-5.1 months) for osteotomy cases and 4.6+/-1.1 months (95% confidence interval, 3.8-5.4 months) for nonosteotomy cases (p = 0.83). However, in the osteotomy group, two patients sustained osteonecrosis of the femoral head, and nonunion remained in 1 patient at the osteotomy site (complication rate, 18%; 3 of 17 patients). There were no complications in the nonosteotomy group (p = 0.26). The average lengthening achieved from osteotomy was 1.0 to 1.5 cm (p < 0.001).

CONCLUSION

Using SCS without SVO to treat femoral neck nonunions can result in a very satisfactory outcome. It is thus preferred for indicated patients. SCS without SVO, however, cannot concomitantly correct a femoral neck shortening; furthermore, shortening may deteriorate because of a telescoping effect. For patients with evident shortening, therefore, combined SVO with SCS is more suitable.

Nonunion and shortening after femoral fracture treated with one-stage lengthening using locked nailing technique. Good results in 48/51 patients

We report on 56 consecutive aseptic femoral shaft nonunions with shortening, which were treated with local debridement, skeletal traction, a spine-spreader aiding lengthening, static locked nail stabilization and corticocancellous bone grafting. 51 patients were followed for 2 (1-4) years and 48 achieved a solid union. The median period to bony union was 4 (3-8) months and lengthening achieved was 2.8 (1.5-4.5) cm. 3 patients had nonunion, 2 without implant failure and 1 with implant failure. However, all 3 healed after reoperation. There was no neurovascular injury or deep infection.

In vitro elution of vancomycin from biodegradable beads

The current antibiotics delivery system for orthopedic infection treatment uses polymethylmethacrylate (PMMA) beads as a drug release. However the nonbiodegradable nature of the PMMA necessitates a second operation to remove the beads. This article explores the alternative of using biodegradable polymers as antibiotic beads for a long-term drug release. The effect of different processing factors on the release rate of the beads was investigated. To manufacture an antibiotic bead, polylactide-polyglycolide copolymers were mixed with vancomycin. The mixture was compressed and sintered at 55 degrees C to form beads of different sizes. An elution method was employed to characterize the release rate of antibiotic over a 35-day period at 37 degrees C. Biodegradable beads released high concentrations of antibiotic (well above the breakpoint sensitivity concentration) in vitro for the period of time needed to treat bone infection; i.e., 4-6 weeks. A bacterial inhibition test was carried out to determine the relative activity of the released antibiotics. The diameter of the sample inhibition zone ranged from 6.5-10 mm, which is equivalent to 12.5-100% of relative activity. By changing the processing parameters, we were able to control the release rate of the beads. This provides advantages of meeting the specific antibiotics requirement for patients with various surgical infections.

Bone healing of tibial lengthening is delayed by cigarette smoking: study of bone mineral density and torsional strength on rabbits

OBJECTIVE

We investigated the effect of intermittent cigarette smoke inhalation on the bone healing of tibial lengthening in rabbits.

METHODS

Twelve male rabbits were divided into two groups of six animals each. The first group underwent intermittent cigarette smoke inhalation, and the second group did not undergo intermittent cigarette smoke inhalation. Each animal's right tibia was lengthened 5 mm by using an uniplanar lengthening device. Bone mineral density (BMD) study was performed for all of the animals 1 day before operation and 3, 4, 5, and 6 weeks after operation. All of the animals were killed 6 weeks postoperatively for biomechanical testing.

RESULTS

By using the preoperative BMD as an internal control, we found that the BMD of the smoke-inhalation group was decreased significantly compared with the non-smoke-inhalation group. The mean %BMD at 3, 4, 5, and 6 weeks were 49.9%, 61.2%, 65.9%, and 71.0%, respectively, in the smoke-inhalation group, whereas the mean %BMD were 54.9%, 71.8%, 76.4%, and 82.0%, respectively, in the non-smoke-inhalation group (two-tailed t test, p > 0.05, p < 0.01, p < 0.01 and p < 0.01 at 3, 4, 5, and 6 weeks, respectively). By using the contralateral nonoperated tibia as internal control, we found that torsional strength of the smoke-inhalation group was decreased significantly compared with the non-smoke-inhalation group. The mean percentage of maximal torque was 63.8% in the smoke-inhalation group, whereas the mean percentage of maximal torque was 77.1% in the non-smoke-inhalation group (two tailed t test, p < 0.01).

CONCLUSION

This study suggests that cigarette smoking delays the mineralization during the bone healing process of distraction osteogenesis and, thus, decreases the mechanical strength of the regenerating bone.

Management of femoral diaphyseal infected nonunion with antibiotic beads local therapy, external skeletal fixation, and staged bone grafting

BACKGROUND

Fifteen patients with femoral shaft fractures complicated by infected nonunions were treated with a two-stage protocol.

METHODS

In the first stage, radical debridement was performed along with antibiotic bead chains local therapy and external skeletal fixation. In the second stage, the debrided nonunion site was repaired with bone grafting and the external skeletal fixator was used until bony union was achieved. The time between the first and second stages of treatment was 2 to 6 weeks. The debrided bone defects ranged from 0.5 to 15 cm. Autogenous iliac cancellous bone grafting was performed in 11 patients, and microvascularized osteoseptocutaneous fibular transfer was performed in 4 patients.

RESULTS

Wound healing and bone union were achieved in all 15 cases. The duration of external fixation of these patients ranged from 7 to 15 months, with an average of 9 months. Minor pin-track infection was seen in seven patients. Postoperative infection after the second-stage bone grafting occurred in three patients. These three infections were arrested by limited debridement along with 2 to 4 weeks of parenteral antibiotic therapy. In one case, stress fracture occurred at 11 months after microvascularized fibular transfer; this was managed with another 5 months of external skeletal fixation. With an aggressive physical therapy program, 10 patients achieved nearly full range of knee motion and 5 patients had relevant knee flexion deficits. The follow-up averaged 58 months (range, 40-76 months); no recurrence of osteomyelitis was observed even at 76 months.

CONCLUSION

We have found that our two-stage treatment with antibiotic beads local therapy, definitive external skeletal fixation, and staged bone grafting is an acceptable treatment protocol for the management of femoral diaphyseal infected nonunion. It results in rapid recovery from osteomyelitis and a predictable recovery from nonunion.

High success rate with exchange nailing to treat a tibial shaft aseptic nonunion

OBJECTIVE

To investigate the effects of tibial exchange nailing in treating a tibial shaft aseptic nonunion and to establish optimal indications for using this technique.

DESIGN

Prospective, consecutive.

SETTING

University hospital.

METHODS

Twenty-five consecutive tibial shaft aseptic nonunions were prospectively treated with the exchange nailing technique. Indications for this procedure were a tibial shaft aseptic nonunion that had previously been treated with an inserted nonreamed or reamed intramedullary nail, displayed less than one centimeter of shortening, was with or without rotational or angular deformity, exhibited no segmental bony defects, and was anatomically suited for conventional or locked reamed intramedullary nail stabilization. The marrow cavity was reamed as extensively as possible, and a rigid intramedullary nail with stable fixation was inserted.

RESULTS

During a follow-up period of two to four years (median thirty-two months), twenty-four nonunions healed, on average, in four months (range three to six months). The one remaining nonunion healed four months after a cancellous bone grafting procedure. No wound infection or malunion was noted.

CONCLUSION

Because of its high union rate, low complication rate, and simplicity of method, we believe that the exchange nailing technique should be considered preferentially for all indicated cases.

Staple augmentation to treat a humeral nonunion after failed Seidel locked nailing

Seidel locked nailing has been successfully used to treat a humeral shaft fracture or nonunion. However, if union fails despite this treatment, the next approach to try has not been well defined. We, therefore, developed a technique using a staple to enforce the local stability without removing the failed nail. The technique was very simple, and the outcome was always satisfactory.

Cementless Roy-Camille femoral component

From 1984 to 1987, a complete, single-layered, porous-coated femoral component (Roy-Camille type) was used for primary cementless total hip replacement in 80 patients. Seventy-two patients (77 hips) with a minimal follow-up of 5 years (mean 7.2 years) were assessed clinically and radiographically. Thigh pain occurred in 4 hips. Osteolysis appeared in 5 hips. Cortical thinning around the femoral component was significant at the proximal and middle levels. In total, 6 femoral components failed, which led to reoperation due to aseptic loosening (4 hips) and septic loosening (2 hips). The hip rating score (modified d'Aubigne and Postel rating system) in the surviving hips progressed from 9.0 (range 6-10) preoperatively to 16.3 (range 12-18) points at the latest follow-up. From this study, we found that the complete, single-layered, porous-coated stem had a low loosening rate after 5 years. Bone ingrowth into the porous coating was found in most of the cases. A lower stress shielding effect in comparison with the complete, multi-layered, porous-coated prosthesis was also noted.