Shortening Technique Research Articles

Influence of Acute Shortening on the Spinal Cord: An Experimental Study

Morphometric changes of the spinal cord and influence on spinal cord-evoked potentials and spinal cord blood flow and postoperative function of hind limbs were studied in various degrees of acute spinal column shortening in dogs. To study the morphometric and physiologic effects of acute spinal column shortening on the spinal cord. The technique of acute spinal column shortening is sometimes applied for correction of spinal deformity, total en bloc spondylectomy operation, or other diseases. However, safe limits and physiologic effects of acute spinal column shortening have not yet been described. Total spondylectomy of T13 was performed in dogs after spinal instrumentation placed 2 levels above and 2 levels below the spondylectomy level. Spinal column was gradually shortened until the lower endplate of T12 contacted the L1 upper endplate (maximum of 20 mm). When any morphologic change of the dural sac or the spinal cord was observed, the length of shortening was measured. Spinal cord-evoked potentials were recorded on the exposed dura mater following epidural stimulation at the C7 level in 8 dogs. Spinal cord blood flow was measured during shortening in 6 dogs. Hindlimb function was evaluated 2 weeks after operation in 10 dogs. No morphometric changes occurred in the dural sac and the spinal cord until shortening of 7.2 +/- 1.7 mm (n = 6). From 7.2 +/- 1.7 to 12.5 +/- 1.1 mm shortening, the dural sac was deformed, whereas the spinal cord maintained its shape. Shortening more than 12.5 +/- 1.1 mm buckled the dural sac, and the spinal cord kinked itself and was compressed by the buckled dura in its concave side (n = 6). No changes could be detected in spinal cord-evoked potentials in 5 or 10 mm of shortening. Spinal cord-evoked potential changes were recorded in the 2 of 6 dogs with 15 mm of shortening. At 20 mm of shortening, spinal cord-evoked potential abnormality was observed in 4 of 6 dogs. At shortening of 5, 10, 15, and 20 mm, spinal cord blood flow was 146 +/- 10%, 160 +/- 21%, 102 +/- 17%, and 93 +/- 7% of the control (29.2 +/- 7.9 mL/100 g/min, n = 6), respectively. All 3 dogs with 10 mm ofshortening had normal hindlimb function 2 weeks after operation. One of the 3 dogs with 15 mm of shortening had paraparesis. Three of the 4 dogs with 20 mm of shortening had also paraparesis after operation. Acute spinal column shortening can be characterized into 3 phases. Phase 1, safe range: occurred during shortening within one-third of the vertebral segment and is characterized by no deformity of the dural sac or the spinal cord. Phase 2, warning range: occurred during spinal shortening between one-third and two-thirds of the vertebral segment and is characterized by shrinking and buckling of the dural sac and no deformity of the spinal cord. Phase 3, dangerous range: occurred after shortening in excess of two-thirds of the vertebral segment and is characterized by spinal cord deformity and compression by the buckled dura. Spinal shortening within the safe range increases spinal cord blood flow.

Pre-osteotomy plate application technique for ulnar shortening.

The self-compressing mode of the AO/ASIF LC-DC plate can be harnessed to close and compress modest osteotomy gaps that are created after provisional application of the plate with two screw holes on either side of the osteotomy. The oblique osteotomy cuts are made through 70% of the bone diameter and the actual osteotomy width is measured. After provisional plate application and removal, the cuts are completed and the plate is re-applied. Eccentric drilling of up to five holes of a 6-hole plate using the 3.5 mm universal drill guide allows closure and compression of osteotomy gaps of up to 4 mm. An interfragmentary screw is placed across the oblique osteotomy through the remaining hole. The technique is simple but requires careful planning and execution.

P43. Influence of acute shortening on the spinal cord: an experimental study

BACKGROUND CONTEXT: The technique of acute spinal column shortening is sometimes applied for correction of spinal deformity, total en bloc spondylectomy operation or other diseases. However, safe limits and physiological effects of acute spinal column shortening have not yet been described.

The long ulnar sliding osteotomy

This study presents a modified technique for performing ulnar shortening osteotomies. The long ulnar sliding osteotomy differs from standard ulnar shortening techniques in 2 ways: (1) a single cut is made in the ulna and (2) screws only are used for fixation.

Tibial shortening for correction of leg length discrepancy and deformity: a new technique

Where length discrepancy occurs in the skeletally mature lower leg, there may be a benefit in using the technique of tibial shortening. Existing techniques have not been widely adopted and are associated with a high incidence of soft tissue complications. We describe a technique of progressive shortening, which we believe is a safe method, having adapted this from techniques for dealing with traumatic bone loss.

Operative Shortening of the Elongated Defunctioned Tendoachillies Following Previous Rupture

Healing of the tendoachilles (TA) following rupture may result in lengthening over a long segment rather than discrete scar interposition. We describe our experience and results of a direct TA shortening technique of dysfunctionally long TAs. Five patients presented with impairment of their sporting level. Four patients had TA injuries that were managed by physiotherapy alone and 1 had been cast immobilised for 6 weeks. At open operation the TAs were found to be confluent but with evidence of scarring over a long segment. A 'Z' shortening was performed. The patients were reviewed up to a mean of 30 months post op. The overall scores were excellent in 1, good in 3 and fair in 1. All returned to their chosen level of sporting activity. The technique described is relatively straightforward and gives predictable improvement in function. It is therefore a useful technique in this often-unrecognised condition

The labial ledge

With aging, orbicularis contractions stretch and elongate the upper-lip area, contributing to an aged appearance. The author describes the ideal height of the labial ledge (mustache area) as shorter or equal to the area from the lower-eyelid margin to the supratarsal crease. He explains his technique of shortening the labial ledge and augmenting the philtral columns and upper and lower lips. (Aesthetic Surg J 2002;22:177-180.)

Macular translocation: unifying concepts, terminology, and classification

PURPOSE: To describe some unifying concepts, terminology, and classification of macular translocation so as to facilitate communication within the scientific community. METHODS: A panel of ophthalmologists with expertise in macular translocation reviewed available data and developed some unifying concepts, terminology, and classification of macular translocation. RESULTS: Macular translocation may be defined as any surgery that has a primary goal of relocating the central neurosensory retina or fovea intraoperatively or postoperatively specifically for the management of macular disease. It may be classified according to the size of the retinotomy and, where applicable, the technique of chorioscleral shortening used. The direction of macular translocation is denoted by the movement of the neurosensory macula relative to the underlying tissues. Effective macular translocation may be defined as successful intraoperative or postoperative relocation of the fovea overlying a subfoveal lesion to an area outside the border of the lesion. The concepts of minimum desired translocation and median postoperative foveal displacement can give some useful idea of the likelihood of effective macular translocation before surgery. CONCLUSIONS: Use of a common standardized terminology for macular translocation will facilitate communication within the scientific community and enhance further research in this area. However, the definitions, terms, classification, and concepts concerning macular translocation are likely to continue to evolve as macular translocation undergoes further modifications and refinements.

成人脱臼性股関節症に対する転子下短縮骨切りを併用した人工股関節全置換術（ＴＨＡ）の経験

Complete congenital dislocation of the hip is one of the most challenging reconstructions in hip arthroplasty. The distorted anatomy in this hip include a high hip center, a small femoral canal, leg length discrepancy, soft tissue contractures, and increased anteversion of the femoral neckshaft angle. Therefore, total hip arthroplasty in CDH has been associated with higher failure and complication rates.We report a case of total hip arthroplasty using subtrochanteric femoral shortening via transverse osteotomy unilateral high-riding congenital dislocation of the hip. This shortening technique was used with non-cemented components, reinforced with bicortical autograft struts and cables. Noncemented acetabular reconstruction was performed at the level of the true acetabulum without bone grafting.The time to union of the osteotomy site was 4 months. JOA scores improved from 52 points preoperatively to 76 points at the latest follow-up at 6 months after surgery.

A new technique of subtrochanteric shortening in total hip arthroplasty: Surgical technique and results of 9 cases

Total hip arthroplasty for severe chronic proximal femoral migration, most commonly seen in congenital dislocation of the hip, has been associated with high rates of complications. A new technique of femoral subtrochanteric shortening osteotomy with the prosthesis in situ is described. This technique minimizes the potential complications, allows for correction of severe femoral neck anteversion, and gives excellent rotational stability, while preserving the proximal femur for better press-fit cementless fixation. In this series, there were 9 cases: 6 women and 2 men with a mean age of 53 years (range, 26-77 years). The average follow-up period was 56 months (range, 6-86 months). The mean preoperative Harris Hip Score was 31 (range, 20-35), and the mean postoperative score was 81 (range, 60-98). At follow-up, all patients reported significant pain relief and functional improvement. All osteotomies appeared to be healed on radiographs by 12 weeks. There were 3 complications. The first complication was a recurrent dislocation resulting from muscle incompetence, which was revised using a constrained liner and a 32-mm head with no further dislocations. The second complication was a breach of the femoral shaft, which was treated operatively using a longer stem. The third complication was a proximal femoral shaft split, which was treated by leaving the cerclage wire in situ. This technique should be considered in cases of congenital dislocation of the hip and when femoral shortening is needed.

Genetics-based multiprocessor scheduling using task duplication

We propose a new genetics-based approach to scheduling parallel program tasks on multiprocessors. In the presence of communication delays, it is shown that task duplication is a useful technique for shortening the length of schedules. Though some genetic algorithms (GAs) for multiprocessor scheduling have been proposed so far, none of them allows task duplication. To overcome this deficiency, we develop a new GA, incorporating new genetic operators to control the degree of replication of tasks. Through simulation studies, we show that the proposed GA works effectively, especially when communication delays are relatively small.

1.TE短縮技術とその効果(MR装置による機能の描出-形態から機能へ-)

1.TE短縮技術とその効果(MR装置による機能の描出-形態から機能へ-)

Callus distraction in tibial defect fractures

Lower leg fractures with an osseous defect can be treated effectively with the callus distraction technique by Bier-Ilizarov. Because osteocytes are cultivated at the site of the defect, a real biological system is working-in contrast to other methods. Especially in lower leg fractures with a denuded tibia, the technique of primary shortening to cover the soft-tissue defect with subsequent compensatory lengthening by callus distraction is valuable. This technique does not need special hospitals but skillful surgeons. A closed surgeon-patient relation ship is required because most treatments are done on an outpatient basis. The cosmetic and functional results are good.

Seidel aberration coefficients for radial gradient-index lenses

Short and accurate analytic formulas for the Seidel coefficients of gradient-index lenses with arbitrary radial refractive-index distributions have been obtained. Starting from analytic ray-tracing formulas, we have developed a technique for decomposing the two components of the transverse aberration of an arbitrary skew ray in surface and inhomogeneous transfer contributions and a technique for shortening the large expressions for the third-order terms resulting from the transfer contributions. Unlike previously known derivation methods, our method delivers simple algebraic expressions for all Seidel coefficients.

Technique for shortening angioplasty guide catheter length when therapeutic catheter fails to reach target stenosis

Occasionally, the usable length of a balloon angioplasty or other therapeutic catheter is insufficient to reach the target stenosis. We describe a technique of shortening the guide catheter from the proximal end in vivo without removing the coronary guidewire. This permits greater projection of the therapeutic catheter to reach distal stenoses.

Comparison of Measurement Techniques for Gate Shortening in Sub-Micrometer Metal Oxide Semiconductor Field Effect Transistors

In this paper, various methods of evaluating the electrical channel length change (or gate shortening) as a result of applied gate voltage in sub-micrometer metal oxide semiconductor field effect transistors (MOSFETs) are investigated and the method best suited for such short channel length devices is reported. Studies were performed on n-channel transistors (n-MOSFETs) fabricated using X-ray and optical lithography and having channel lengths in the range of 0.4 to 4 µm and 1.5 to 10 µm respectively. The effective channel lengths were extracted from the current-voltage (I-V) measurements. The measurements were made for different low and high sets of gate voltages. In comparing various methods it was found that the method due to Terada and Muta, and Chern et al. gave accurate results consistently for short channel MOSFETs, whereas the Whitfield method gave accurate results only for larger channel length MOSFETs. The accuracy of the Whitfield method is sensitive to applied gate voltage during I-V measurements. The Peng and Afromowitz method is unsuitable for finding the effective channel length of sub-micrometer MOSFETs especially if the MOSFETs have high values of external resistance.

Lateral canthoplasty.

BACKGROUND. Lateral canthoplasty is one of the most valuable procedures in ophthalmic plastic surgery and has a variety of indications. These include the repair of ectropion, paralytic lagophthalmos, and eyelid retraction. The procedure can also be used in the prevention of some of the above entities, in the delivery of orbital tumors, and is a valuable adjunct in lower blepharoplasty. The tarsal strip procedure is probably the most popular technique of horizontal shortening of the eyelid. OBJECTIVE. Indications for this procedure are reviewed. The technique as I perform it is described in detail.

Shortening of Free-running XeCl Laser Pulses by Stimulated Brillouin Scattering

Abstract A stimulated Brillouin scattering mirror has been used to ‘temporally tune’ from nanoseconds to subnanoseconds the width of laser pulses generated by a free running XeCl oscillator, equipped with a super-Gaussian reflectivity unstable resonator. Pulse shortening techniques by stimulated Brillouin scattering (SBS) and by truncated SBS have been investigated. A maximum pulse shortening of about fifty has been achieved by truncated SBS.

Generation of high peak power excimer laser radiation by pulse shortening

Techniques for shortening the pulses of a commercial oscillator-amplifier excimer laser have been investigated. By a combination of a H2-Raman cell and a saturable absorber dye jet the oscillator pulses are shortened from about 25 ns to typically 1.5 ns. Upon amplification pulses around 3.5 ns with peak powers of more than 100 MW for KrF (248 nm) and 25 MW for XeCl (308 nm) are obtained.

Screening methods for caloric testing.

In order to evaluate the screening capacity and the reliability of monothermal caloric stimulation, the caloric results obtained in 272 patients have been reviewed. The results of a complete bithermal 4-test-set are compared with the results of the hot and cold stimulation considered separately. The supposition that a complete 4-test set is necessary only if the monothermal reaction shows significant asymmetry, is tested by determining how far this would lead to a correct evaluation compared with the final results obtained by the bithermal testing. The study shows that hot as well as cold monothermal screening would result in too many false positive as well as false negative findings. A test procedure consisting of an alternating bithermal stimulation is proposed as a technique for shortening the examination time. This technique has proven to be reliable and it is also more comfortable for the patient.