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At least 55 records · Page 3Linked to original sources
PubMed2003

Dual-rod correction and instrumentation of idiopathic scoliosis with the Halm-Zielke instrumentation.

STUDY DESIGN: A prospective clinical and radiographic evaluation of 45 consecutive patients with idiopathic adolescent and adult scoliosis treated with anterior dual-rod Halm-Zielke instrumentation. OBJECTIVES: Clinical and radiographic evaluation with a minimum follow-up of 2 years. SUMMARY OF BACKGROUND DATA: Halm-Zielke instrumentation was developed to eliminate the disadvantages of Zielke instrumentation in terms of lack of primary stability and a kyphogenic effect. METHODS: All patients underwent an identical anterior surgical technique with the Halm-Zielke instrumentation of the primary curve. The system is composed of a lid-plate, which is fixed to the lateral aspect of the vertebral body with two screws: a sunk screw anteriorly and a ventral derotation spondylodesis (VDS) screw posteriorly. The lid-plate design provides the lowest possible implant profile. The longitudinal components consist of a threaded rod and a solid, fluted rod. Correction is performed with both the threaded and the solid rod. The solid rod allows derotation and correction of the sagittal plane and provides primary stability. RESULTS: Preoperative curves ranged from 35 degrees to 92 degrees Cobb angle. Final correction of the frontal plane averaged 67% within the instrumented levels and 59% for the total primary curve. The apical vertebral rotation of the primary curve was corrected by 52% on average without loss of correction during follow-up. Thoracolumbar kyphosis was present in 11 patients and corrected in all cases from an average of 20 degrees to 2 degrees after surgery and to 8 degrees at follow-up. We observed two cases of implant failure with one resulting in a pseudarthrosis. CONCLUSION: Halm-Zielke instrumentation proved to be a major improvement of the original VDS-Zielke. It eliminates the kyphogenic effect and provides primary stability.

Adolescent↗
PubMed1990

[Experimental examinations about the influence of prosthetic therapeutic remedies for players on a wind-instrument as to the quality of the instrumental sound].

In 20 professional players on a wind-instrument (10 musicians on wood wind-instruments, 10 ones on brass wind-instruments) the condition was examined if there are significant connections between the meanwhile applied prosthetic therapeutic remedies (imitated by measuring bodies) and the instrumental sound produced by them. The sound quality was analysed as to the quality as well as to the quantity by an appropriate narrow band spectrometer, and a sound index was figured out. By this method we succeeded in demonstrating the use of a maxillary plate in the anterior third of the palate and that one of back-ground splints in the upper front tooth region of players on brass wind-instruments to cause significant sound changes. Additionally, a significant change in sound impression was stated by placing a maxillary plate into the middle of the third of the palate. Thus we succeeded to point out the prosthetic-critical zones of players on a wood wind- and a brass wind-instrument.

Adolescent↗
PubMed1997

Endodontic hand instruments: cutting efficiency, instrumentation of curved canals, bending and torsional properties.

In an assessment of the usefulness of different root canal instruments, two aspects are of particular interest for the endodontist: the cutting efficiency of the instruments and their ability to enlarge curved canals without undesirable changes of the canal shape such as the formation of zips and elbows. This review paper is based on own investigations on the cutting efficiency and instrumentation of curved canals. Additionally, two parameters which are described in ISO 3630-1, resistance to bending and resistance to fracture, are discussed. With regard to cutting efficiency in rotary motion, flexible stainless steel reamers and K-files clearly display the best results and are superior to conventional stainless steel as well as titanium-based reamers and K-files. Regarding cutting efficiency in linear motion, stainless steel Hedström files made by certain manufacturers are significantly superior to stainless steel and titanium-based Hedström files of other brands. Flexible stainless steel instruments with modified noncutting tips clearly produce the best canal shape in curved canals. With only rare exceptions, all the instruments tested fulfilled the requirements of the ISO standard concerning resistance to fracture and resistance to bending.

Alloys↗
PubMed2000

Cleaning dental instruments: measuring the effectiveness of an instrument washer/disinfector.

PURPOSE: To analyze the cleaning effectiveness of one type of instrument washer available for use in a dental office. MATERIALS AND METHODS: Dental instruments were heavily contaminated with blood and specific test bacteria. They were placed in cleaning baskets or within instrument cassettes, processed through the instrument washer, and analyzed for remaining blood and viable bacteria. RESULTS: Information obtained indicated that the washer is an effective cleaning system for dental instruments.

Bacteria↗
PubMed2006

Dynamic light scattering in turbid colloidal dispersions: a comparison between the modified flat-cell light-scattering instrument and 3D dynamic light-scattering instrument.

It remains a challenge to measure dynamics in dense colloidal systems. Multiple scattering and low light-transmission rates often hinder measurements in such systems. One of the well-established techniques for overcoming the problem of multiple scattering is cross-correlation techniques such as 3D dynamic light scattering (3D-DLS). However, a high degree of multiple scattering, i.e., vanishing single-scattering contribution in the signal, limits the use of the 3D-DLS technique. We present another approach to measure turbid media by way of upgrading our flat-cell light-scattering instrument (FCLSI). This instrument was originally designed for static light-scattering (SLS) experiments and is similar to a Fraunhofer setup, which features a flat sample cell. The thickness of the flat sample cell can be varied from 13 mum to 5 mm. The small thickness increases the transmission, reduces multiple scattering to a negligible amount, and therefore enables the investigation of dense colloidal systems. We upgraded this instrument for DLS measurements by the installation of an optical single-mode fiber detector in the forward scattering regime. We present our instrumentation and subsequently test its limits using a concentration series of a turbid colloidal suspension. We compare the performances of our modified flat-cell light-scattering instrument with that of standard DLS and with that of 3D-DLS. We show that 3D-DLS and FCLSI only have a comparable performance if the length of the light path in the sample using the 3D-DLS is reduced to a minimum. Otherwise, the FCLSI has some advantage.

Journal Article↗
PubMed1993

Apical third instrumentation of curved canals with K-type and canal master instruments.

Forty acrylic blocks with curved canals were divided into two groups of 20 each. One group had canals with 30-degree curvature and the other with 45-degree curvature. Each group was divided into two subgroups of 10 blocks each. One subgroup was instrumented with precurved Kerr files and the other was instrumented with Canal Master hand instruments. The efficiency of the two instruments for preparing the apical third of curved canals was compared. In plastic blocks, Canal Master caused less transportation and was more suitable for instrumenting the canals.

Dental Cavity Preparation↗
PubMedDate not supplied

The effect of spinal instrumentation particulate wear debris. an in vivo rabbit model and applied clinical study of retrieved instrumentation cases.

STUDY DESIGN: The current study was undertaken to determine if the presence of spinal instrumentation wear particulate debris deleteriously influences early osseointegration of posterolateral bone graft or disrupts an established posterolateral fusion mass. OBJECTIVES: Using an in vivo animal model, the first phase (basic science) of this study was to evaluate the effect(s) of titanium wear particulate on a posterolateral spinal arthrodesis based on serological, histological and immunocytochemical analyses. The second phase (clinical) was to perform the same analysis of soft tissue surrounding spinal instrumentation in 12 symptomatic clinical patients. SUMMARY OF BACKGROUND DATA: The effect of unintended wear particulate resulting from micromotion between the interconnection mechanisms in spinal instrumentation remains a clinical concern. METHODS: Thirty-four New Zealand White rabbits were randomized into two groups based on postoperative time periods of 2 months (Group 1, n=14) and 4 months (Group II, n=20). Group I underwent a posterolateral arthrodesis (PLF) at L5-L6 using tricortical iliac autograft or tricortical iliac autograft plus titanium particulate. Group 2 all received iliac autograft at the initial surgery and were reoperated on after 8 weeks and treated with PLF exposure alone or titanium particulate. Postoperative analysis included serological quantification of systemic cytokines. Postmortem microradiographic, immunocytochemical and histopathological assessment of the intertransverse fusion mass quantified the extent of osteolysis, local proinflammatory cytokines, osteoclasts and inflammatory infiltrates. Clinical aspect of study: Over the last 2 years, 12 patients more than 0.4 years after spinal instrumentation presented with painful paraspinal inflammation. At surgical exploration, the cultures were negative for infection and the surrounding soft tissue was examined for cytokine reactions. There was loosening of implants and osteolysis in the location of the wear debris in 8 of 12 patients. RESULTS: Basic science phase: serological analysis of systemic cytokines indicated no significant differences in cytokine levels (p>.05) between the titanium or autograft treatments. Immunocytochemistry indicated increased levels of local cytokines: TNF-alpha at the titanium-treated PLF sites at both time periods (p<.05). Osteoclast cell counts and regions of osteolytic resorption lacunae were higher in the titanium-treated versus autograft-alone groups (p<.05), and the extent of cellular apoptosis was markedly higher in the titanium-treated sites at both time intervals. Electron microscopy indicated definitive evidence of phagocytized titanium particles and foci of local, chronic inflammatory changes in the titanium-treated sites. Clinical aspect: Eleven of 12 clinical cases demonstrated elevated TNF-alpha levels and an increased osteoclastic response in the vicinity of wear debris caused by dry frictional wear particles of titanium or stainless steel. Osteolysis most commonly involved loose transverse connectors. Resection of the wear debris and surrounding fibroinflammatory glycocalyx resulted in resolution of clinical symptoms in all 12 cases. CONCLUSIONS: Titanium particulate debris introduced at the level of a spinal arthrodesis elicits a cytokine-mediated particulate-induced response favoring proinflammatory infiltrates, increased expression of intracellular TNF-alpha, increased osteoclastic activity and cellular apoptosis. This is the first basic scientific study and the first clinical study demonstrating associations of spinal instrumentation particulates wear debris and increased cytokines and increased osteoclastic activity. Osteolysis is the number one cause of failure of orthopedic implants in the appendicular skeleton. Spinal surgeons need to increase their awareness of this destructive process.

Acid Phosphatase↗
PubMed1989

Spine fusion in cerebral palsy with L-rod segmental spinal instrumentation. A comparison of single and two-stage combined approach with Zielke instrumentation.

The benefits of achieving rigid internal fixation and eliminating the need for postoperative external orthotic support with L-rod spinal instrumentation made it desirable for use in the surgical treatment of neuromuscular scoliosis. From May 1981 to May 1985, 31 severely involved cerebral palsy patients with progressive spinal deformity underwent posterior fusion and L-rod instrumentation. All patients except one were nonambulatory. Surgical indications included prevention of curve progression, correction of pelvic obliquity, and achievement of balanced spinal alignment in order to improve sitting balance and tolerance without external spinal orthotic support. Ten patients (Group I), with an average age of 15.2 years, with double major or flexible paralytic C-curves or scoliosis measuring less than 70 degrees, underwent posterior fusion and L-rod instrumentation only. Twenty-one patients (Group II), with an average age of 22.1 years, with thoracolumbar, lumbar, or rigid paralytic C-curves or scoliosis measuring greater than 70 degrees, underwent initial anterior release, bone grafting, and Zielke instrumentation followed by second-stage L-rod instrumentation. In Group I, scoliosis averaged 57 degrees and postoperatively 27 degrees (53% correction). In Group II, scoliosis averaged 88 degrees and postoperatively 36 degrees (63% correction). Fifteen Group II patients had posterior fusion extend into the sacrum using the Galveston technique. Six Group II patients were not fused into the sacrum. Scoliosis and pelvic obliquity were corrected in both groups. Torso decompensation improved to 2.7 cm in the Galveston group, but increased to 5.6 cm at follow-up in the patients not fused into the sacrum.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2000

The biomechanical effect of postoperative hypolordosis in instrumented lumbar fusion on instrumented and adjacent spinal segments.

STUDY DESIGN: Change in lumbar lordosis was measured in patients that had undergone posterolateral lumbar fusions using transpedicular instrumentation. The biomechanical effects of postoperative lumbar malalignment were measured in cadaveric specimens. OBJECTIVES: To determine the extent of postoperative lumbar sagittal malalignment caused by an intraoperative kneeling position with 90 degrees of hip and knee flexion, and to assess its effect on the mechanical loading of the instrumented and adjacent segments. SUMMARY OF BACKGROUND DATA: The importance of maintaining the baseline lumbar lordosis after surgery has been stressed in the literature. However, there are few objective data to evaluate whether postoperative hypolordosis in the instrumented segments can increase the likelihood of junctional breakdown. METHODS: Segmental lordosis was measured on preoperative standing, intraoperative prone, and postoperative standing radiographs. In human cadaveric spines, a lordosis loss of up to 8 degrees was created across L4-S1 using calibrated transpedicular devices. Specimens were tested in extension and under axial loading in the upright posture. RESULTS: In patients who underwent L4-S1 fusions, the lordosis within the fusion decreased by 10 degrees intraoperatively and after surgery. Postoperative lordosis in the proximal (L2-L3 and L3-L4) segments increased by 2 degrees each, as compared with the preoperative measures. Hypolordosis in the instrumented segments increased the load across the posterior transpedicular devices, the posterior shear force, and the lamina strain at the adjacent level. CONCLUSIONS: Hypolordosis in the instrumented segments caused increased loading of the posterior column of the adjacent segments. These biomechanical effects may explain the degenerative changes at the junctional level that have been observed as long-term consequences of lumbar fusion.

Adult↗
PubMed2004

A comparison of highly instrumented and minimally instrumented unicompartmental knee prostheses.

In this study, two specific implants are compared: the Oxford prosthesis, which uses a highly instrumented technique and was placed through a traditional arthrotomy; and the Repicci prosthesis, which uses a minimally instrumented technique and was placed with a minimally invasive surgical approach. The study looked specifically at limb alignment, because achieving appropriate alignment is correlated with the best long-term implant function and achieving alignment is a function of the implant instrumentation. The rationale of more instrumentation for a surgical technique is to add precision and reproducibility; less instrumentation requires less surgical exposure and therefore is more minimally invasive. The senior author presents his long-term experience with the Oxford implant (55 implants; average followup 10.4 years) and short-term experience with the Repicci implant (164 implants; average followup 1.3 years for the first 30 implants.). With available followup, the clinical results using both implants have been favorable. The average alignment of the Oxford prosthesis was 5.6 degrees valgus and the average alignment of the Repicci prosthesis was 4.5 degrees valgus. Side-to-side long-term comparison is not yet available, although the literature would suggest that both implants can have satisfactory long-term results. Specific implant selection probably is not as important as precise patient selection.

Arthroplasty, Replacement, Knee↗
PubMed2006

In vitro comparison of NiTi rotary instruments and stainless steel hand instruments in root canal preparations of primary and permanent molar.

This study is an attempt to compare the NiTi rotary and K-files hand instrumentation on root canal preparation of primary and permanent molars for their efficiency in preparation time, instrument failure and shaping the canals. About 20 primary mandibular second molar (I) and 20 permanent mandibular first molar (II) were selected. Each was further divided into 10 for K-files (a) and 10 for NiTi (b) groups, respectively. Results showed that preparation time Ib Ia and IIab<IIa, which was highly significant. In instrument failure, Ia (40%), IIa (30%) showed more deformation but not fracture and Ib (10%), IIb (20%) showed fracture, but not deformation. Profiles showed good canal taper and smoothness compared to the K-files. To conclude profile 0.04 taper 29 series, prepared canal rapidly than conventional K-file with good taper, smoothness though the flow was not satisfactory. Instrument failure with K-files was less. In primary teeth preparation time, instrument failure with profile was less compared to the permanent. To conclude it's encouraging to use the profiles in primary teeth.

Dental Alloys↗
PubMed2003

Clinical outcome in monosegmental fusion of degenerative lumbar instabilities:instrumented versus non-instrumented.

BACKGROUND: Degenerative lumbar instabilities are one of the major reasons for low back pain, especially in elderly people. There is still controversy in the literature about the clinical outcome of instrumented monosegmental fusions compared to noninstrumented posterolateral fusions. MATERIAL/METHODS: In this study we described the postoperative outcome of 33 patients who underwent posterolateral monosegmental spinal fusion:instrumented (17 patients)or noninstrumented (16 patients).All patients received the same instrumentation system. Medical history (considering daily activities,sports,social contacts and quality of life),clinical examination and radiological analysis served as evaluation parameters. Data were collected by a questionnaire based on the Oswestry Disability Score for low back pain. RESULTS: 86.6%of all subjects showed an improvement of postoperative health status. Although patients with fusion without internal fixation needed a reduced dose of postoperative analgesics compared to the monosegmental non-instrumented group,there were no statistical differences in patient-reported,clinical and radiographical outcome between the two groups. CONCLUSIONS: The results do not indicate a benefit in outcome from added instrumentation in elective lumbar fusions. This should be considered in each single case when a spinal fusion in the treatment of degenerative lumbar instability is indicated.

Adult↗
PubMed1999

A comparison of instrumentation using Naviflex and Profile nickel-titanium engine-driven rotary instruments.

This study was designed to compare the changes in canal configuration resulting from instrumentation by either Profile or Naviflex instruments. Forty mesial canals in extracted human molar teeth were embedded and sectioned at two root levels. Reassembled teeth were instrumented with a modified crown-down technique as described in the Profile training video for Profile files and in a similar manner for Naviflex instruments. Superimposed pre- and postinstrumented cross-sectional root images were projected, traced, and scanned into a computer for analysis. Canal movement, in relation to the furca, and canal area change were recorded. The results showed no significant difference in canal center movement or canal area change between the Profile or Naviflex groups. The degree of canal curvature had no effect on canal center movement or canal area change.

Dental High-Speed Technique↗
PubMed2005

[Surgical instruments (I). An introduction to surgical instruments].

In surgical wards, the variety and increasing complexity of techniques used, together with the high number of materials and instruments employed, demands that professionals who join these wards have a specific professional development related to instruments and techniques. In this short series of articles, the author shall present distinct manners to gain knowledge about instruments in such a way that at the end of this series, professionals who are interested will have a guide to help them acquire a deep understanding of surgical instruments, their common usage and their specialized characteristics. A bibliography will be included with the last article.

Equipment Design↗
PubMed1994

[An instrument for positioning elastic ligatures (ligature instrument)].

The ligature instrument is constructed for placing in position elastomeric ligatures. The instrument has two types--one designed for fore-teeth area and one for premolars and molars--traditional or ergonomical aspects were taken into consideration with metal or sterilizable plastic handle. This instrument fills a long felt gap because to complete this process until now no such type of special instrument existed.

Dental Instruments↗
PubMed1995

[In vitro comparison of instruments for root canal preparation. III. Study of the instruments from the viewpoint of shaping asymmetry].

The shape of the prepared root canals is not consistent with the original anatomical shape in the majority of curved canals. The discrepancy is dependent of the type of instrument, the original anatomical form of the root canal and the location of the measurement. The original shape of the root canal has to be taken into consideration in the selection of preparatory instruments because their application is limited by the above mentioned factor. The sonic and ultrasonic preparatory instruments form an exception in this respect due to their non aggressive way of shaping. These instruments cannot be disregarded in the preparation of curved root canals.

Dental Instruments↗
PubMed2003

Development of a new instrument for rheumatoid arthritis: the Cedars-Sinai Health-Related Quality of Life instrument (CSHQ-RA).

OBJECTIVE: To update and complement existing instruments, we developed a multidimensional disease-specific instrument, intended to reflect the impact of rheumatoid arthritis (RA) with modern treatment options on patient's Health-Related Quality of Life (HRQOL). METHODS: Items were developed from a systematic review of published HRQOL measures and transcripts of RA patient focus groups. Items were refined by an expert panel and administered to 350 patients for psychometric testing. RESULTS: The systematic review identified 228 potential items, and the focus group transcripts identified 96 additional items. Expert review and pilot testing resulted in an initial 58-item instrument. Twenty-six items were excluded due to floor/ceiling effects, poor response rates, or high item-item correlations. Factor analysis identified a 5-factor structure (eigenvalues >or=1). Multi-trait scaling performed on both completed surveys confirmed the 5 sub-scale structure (Cronbach's > 0.87). CONCLUSION: The CSHQ-RA consists of 33 items that address 5 HRQOL domains, each with high internal consistency. Additional testing will assess the instrument's validity and responsiveness.

Adult↗