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Biomedical subjects

V H Frankel

Publications and source records attributed to V H Frankel.

At least 19 recordsLinked to original sources
PubMed1992

Humeral lengthening and bone transport using the Ilizarov technique.

The authors present their results of Ilizarov treatment of eight humeral length deficits and bone defects in seven consecutive patients treated at the Hospital for Joint Diseases. The mean humeral lengthening achieved was 9.8 cm. The lengthening goal was completely achieved in six cases, while two cases achieved over 80% of the desired length. No permanent neurovascular or infectious complication occurred. The authors suggest that the Ilizarov technique is a viable method in treating severe humeral length deficits or bone defects.

Adolescent↗
PubMed1992

New method of limb deformities correction in children.

A new "bloodless" technique (Ilizarov) was used to correct 36 limb deformities in 29 children. There were six leg length discrepancies, five achondroplasias, four deformed feet, five joint contractures, one rotational deformity of tibia, and in three the apparatus was used as an external fixator after corrective osteotomy. Lengthening was accomplished in 15 of the 16 procedures (93%). Average increase in femur length was 10 cm (32%), in tibial length 7.5 cm (30%), in humerus 11 cm (40%). Bony union was achieved in two out of five pseudoarthroses. Four deformed feet were fully corrected. Joint contractures were corrected in four out of five. The complication rate is as high as in other methods but with the Ilizarov apparatus, longer segments of bone were lengthened and more complex deformities were treated. Complications lessened as experience was gained.

Achondroplasia↗
PubMed1992

Canine leg lengthening by the Ilizarov technique. A biomechanical, radiologic, and morphologic study.

The mechanical properties of canine tibias lengthened by the Ilizarov method as well as the degree of healing--as determined by the osseous appearance of the limbs using three imaging modalities--were examined as a function of fixator application time. Sixteen mongrel dogs had right tibial lengthening using a two-ring Ilizarov external fixator. The average lengthening was 27 mm. Four groups of four animals were killed at four, six, eight, and ten weeks after the completion of lengthening. The operated and contralateral tibias were examined with biplanar roentgenography, computerized tomography, and technetium scintigraphy. The torsional strengths of the tibias were then determined and histologic analysis was performed. There was considerable variation in the healing rate of the lengthening sites, both within and among groups. Histologic analysis and results of the imaging modalities revealed different degrees of development of the lengthening sites among members of the same group. Two types of mechanical behavior were seen, corresponding to completely and incompletely ossified lengthening zones. The strongest samples were those that had ossified across their lengthening sites by four or six weeks. The degree of recorticalization of the new bone and the extent of formation of a marrow space correlated well with increased torsional strength. The average strength of the fully ossified bones decreased progressively with time, paralleling a decrease in cortical thickness outside the lengthening zone. This seems to be a consequence of stress shielding by the fixator and disuse by the animal.

Animals↗
PubMed1992

The effect of wire configuration on the stability of the Ilizarov external fixator.

The stability of the basic unit for fixation of the Ilizarov external fixation system was tested in several loading modes. The effects of varying the number of wires and the orientation of wire placement were studied. The fixation units were mounted on a plastic, simulated, long bone and tested by loading in several directions. The Ilizarov fixation ring was found to be relatively stiff in axial compression and torsion. Its stiffness in this mode was directly proportional to the number of wires in the system and independent of the configuration of wire placement. Loading in bending and in shear provided much lower levels of stiffness, and this was dependent on the angles formed between the wires. The addition of a wire at a minimum distance of 4 cm from the primary ring significantly improved bending stiffness. The use of opposed olive wires also improved shear stiffness.

Equipment Design↗
PubMed1992

Hip fractures in geriatric patients. Results of an interdisciplinary hospital care program.

The care of geriatric patients who sustain hip fractures is difficult because of associated medical comorbidities, the risk of medical and surgical complications, and the functional limitations that are often present before the fracture. The authors developed and used a comprehensive, interdisciplinary care program that has so far treated 431 geriatric hip fracture patients. The results of the program group were compared to a matched nonprogram group of patients (n = 60) cared for before the initiation of the program (and before the initiation of diagnosis-related groups). The program patients had fewer postoperative complications, significantly fewer (p less than .05) intensive care unit transfers (10.2% versus 20%), significantly improved (p less than .001) ambulatory ability at discharge (56.3% independent with assistive devices versus 18.2%), and proportionately fewer discharges to nursing homes (8.1% versus 19.3%). These results support the use of an interdisciplinary approach as a means of improving the inhospital care of geriatric hip fracture patients.

Aged↗
PubMed1991

Fatigue failure of the sliding screw in hip fracture fixation: a report of three cases.

Hardware failure of the sliding screw system used in hip fracture fixation is rare. The fatigue failure of the sliding screw is always related clinically to nonunion or refracture along the path of the screw. In both situations, cyclic loading of the implant exceeds its endurance limit, and failure can ensue. Three cases of failure of the sliding screw are presented: a nonunion of a basicervical fracture, a nonunion secondary to stress fracture at the plate-barrel junction, and a refracture through the femoral neck after healing of an intertrochanteric fracture. A biomechanical analysis of the stresses on the sliding screw focuses on design features such as the internal threaded region used for the compression screw or the barrel length that creates increased stresses in the screw, thus lowering the number of cycles to failure. Based on this analysis, recommendations are made concerning implant design and surgical technique.

Adult↗
PubMed1991

Ilizarov bone transport in large bone loss and in severe osteomyelitis.

Eleven patients, 21-53 years of age, were treated for large tibial (9), femoral (1), or humeral (1) bone loss (4-16 cm) by the Ilizarov technique of external or internal bone transport. Bone defects were closed from within. Bone grafts were not used; instead, a free bone fragment was moved gradually internally by distraction to fill the defect. In cases of severe osteomyelitis, a large fragment (up to 16 cm) of affected bone was resected and the defect was filled by the same technique. Seven patients had external bone transport, three patients had internal bone transport, and one patient had combined external-internal bone transport. The duration of treatment was 5-28 months (mean, 12 months). Excellent results were achieved in eight patients, good results in two patients, and a fair result in one patient. Complications included two fractures of regenerated bone as a result of a second trauma, one 3-cm shortness of a limb, one development of foot equinus, and one incidence of transient peroneal nerve palsy.

Adult↗
PubMed1990

Environmentally induced disorders of the musculoskeletal system.

The human suffering and economic cost attributable to musculoskeletal disorders cannot be overemphasized. Biomechanical principles have been introduced to explain the microtrauma and macrotrauma as mechanisms of injury. Stress-induced remodeling is a useful paradigm in the study of environmentally induced disorders. The concept of environment should include psychosocial and organizational factors with respect to musculoskeletal complaints and chronic pain. Low back pain, osteoarthritis, osteoporosis and its associated fractures, and cumulative trauma disorders are the most critical and common musculoskeletal disorders. The risk factors for low back pain have been identified, and preventive measures for reducing the chronicity of low back pain have been discussed. Preventive approaches to control or limit the fractures associated with osteoporosis and loss of bone mass are preferred to simple management of the fracture of osteoporotic patients. It can be concluded that too little or too much stress can disturb the homeostatic or the equilibrium state of health and that much remains to be researched to quantify the optimal stress levels.

Back Pain↗
PubMed1990

Analysis of removed autophor ceramic-on-ceramic components.

Six Autophor alumina ceramic total hip arthroplasty components (5 removed for stem loosening and 1 for cup loosening) were evaluated to determine the nature and extent of wear by direct measurement, scanning electron microscopy of wear debris, and histology. Component implantation averaged 29 months (range, 8-54 months). All components had evidence of marked wear, including gross loss of material, which increased with the duration of implantation.

Adult↗
PubMed1990

A biomechanical analysis of the sliding hip screw: the question of plate angle.

There is general agreement that the implant of choice for intertrochanteric fractures is the sliding hip screw (SHS). However, considerable differences of opinion exist as to which plate angle--varying from 130 to 150 degrees--is preferred. Thus far there has been no cadaver-based biomechanical analysis of this problem. To examine these questions, we determined the effect of plate angle on plate strain and proximal medial femoral strain distribution in cadaver femurs fixed with 130, 135, 140, 145, and 150 degrees SHS after experimentally produced stable and unstable intertrochanteric fractures. Twenty-four fresh adult cadaver femurs were assigned randomly to either the 130, 135, 140, 145, or 150 degrees SHS group. Each femur was radiographed and bone mineral density was determined by dual-photon absorptiometry. Multiple-strain gauges were affixed to the femur, with specific focus on the proximal femur and plate. Femurs were loaded at 25 degrees adduction in increments of 70 N from 0 to 1,800 N in a servohydraulic testing machine. Femurs were tested in a progressive manner: (a) intact femur; (b) intact femur with SHS inserted; (c) a stable two-part intertrochanteric fracture reduced with SHS; (d) a four-part fracture with the posteromedial fragment (PMF) reduced anatomically by a lag screw; (e) the same fracture with the PMF rotated 180 degrees and held in place by a lag screw to approximate a "near-anatomic" reduction; and (f) the same fracture with the PMF discarded. Screw sliding measurements were determined at regular intervals throughout each test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Closed treatment of canine nonunions by controlled compression and distraction using an Ilizarov fixator: a preliminary study.

The Ilizarov fixator was used for closed treatment of canine nonunions by controlled compression and distraction. The fibrous matrix and cartilage formed within the nonunion site transformed to osteoid and bone with increased vascularity. Healing was demonstrated by substantial bone bridging the nonunion at 6 weeks. The Ilizarov method appears to be a viable treatment for nonunions.

Animals↗
PubMed1990

Technical note: a graphic method for the analysis and correction of multiplanar deformities.

A method for analyzing and correcting bone deformities with coronal, sagittal, and horizontal components is presented. It consists of the application of vector analysis in three-dimensional space to these clinical situations. The deformity correction is performed by determining the proper orientation in space of a treatment axis and rotating the limb segment about this axis so that all three deformity components correct simultaneously. This method has special application for the gradual correction of deformities by means of modular external fixators.

Bone Diseases↗
PubMed1989

Reproducibility of trunk isoinertial performances in the sagittal, coronal, and transverse planes.

A new triaxial dynamometer to quantify the performance of trunk muscles has been developed, and a study was conducted to determine the best control parameters to use with this triaxial isodynamic mode of testing. Nine male subjects were tested at three resistance levels in the sagittal, coronal, and transverse planes. The purpose was to establish the reproducibility of the performance parameters in each plane at all resistance levels, and to identify those parameters which gave the most reliable information for objective assessment of the low back functional state. Measured torque had the highest reproducibility rate, and the most reliable assessments were obtained at the highest resistance level.

Adult↗
PubMed1988

Musculoskeletal demands on flamenco dancers: a clinical and biomechanical study.

The flamenco dancer acts on the floor like a drummer. The percussive footwork and vibration patterns created during dancing impose unusual demands on the musculoskeletal system. This study investigated the clinical and biomechanical aspects of this task. Using the electrodynogram and skin-mounted accelerometers, foot pressures as well as hip and knee vibrations were recorded in 10 female dancers after a thorough clinical evaluation. A health questionnaire was also distributed to 29 dancers. Foot pressures and acceleration data reveal the percussive nature of the dance. Some clinical findings, like calluses, are related to pressure distribution. Urogenital disorders, as well as back and neck pain, may be related to the vibrations generated by the flamenco dance form. The hip joint seems to absorb most of the impacts. "Vibration-pressure" diagrams are suggested as a useful tool for evaluating a dancer's biomechanical behavior, as well as the effect of floors and footwear on this behavior.

Adult↗
PubMed1988

The Ilizarov technique.

The Ilizarov method for limb lengthening and reshaping is based on sound clinical investigation and animal laboratory studies. Although new to this country, it has been used successfully in the Soviet Union for 35 years. As with all new procedures, one must learn the technique and become familiar with the apparatus before attempting to perform the surgery. Three case histories are presented which were among the first in the United States to be treated by the application of the Ilizarov technique and external fixator.

Adult↗
PubMed1988

Axial malalignment in femoral neck fractures. An experimental study.

Varus, valgus, and retroversion-anteversion displacements of femoral neck fractures are easily identified on standard AP and lateral radiographs, but rotational malalignments are frequently overlooked. Alterations of the normal appearance of the trabecular systems will indicate rotatory malalignments. A misleading picture of what seems to be severe osteoporosis may actually be due to malrotation and disappearance of the normal trabecular pattern on radiograph.

Bone Nails↗