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A H R W Simpson - One of the best experts on this subject based on the ideXlab platform.
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Leg Lengthening over an intramedullary nail
Journal of Bone and Joint Surgery American Volume, 1999Co-Authors: A H R W Simpson, A S Cole, John KenwrightAbstract:Distraction osteogenesis is widely used for Leg Lengthening, but often requires a long period of external fixation which carries risks of pin-track sepsis, malalignment, stiffness of the joint and late fracture of the regenerate. We present the results of 20 cases in which, in an attempt to reduce the rate of complications, a combination of external fixation and intramedullary nailing was used. The mean gain in length was 4.7 cm (2 to 8.6). The mean time of external fixation was 20 days per centimetre gain in length. All distracted segments healed spontaneously without refracture or malalignment. There were three cases of deep infection, two of which occurred in patients who had had previous open fractures of the bone which was being lengthened. All resolved with appropriate treatment. This method allows early rehabilitation, with a rapid return of knee movement. There is a lower rate of complications than occurs when external fixation is used on its own. The time of external fixation is shorter than in other methods of Leg Lengthening. The high risk of infection calls for caution.
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the role of chondrocytes in intramembranous and endochondral ossification during distraction osteogenesis in the rabbit
Calcified Tissue International, 1999Co-Authors: A H R W Simpson, J T TriffittAbstract:We have used a rabbit Leg-Lengthening model for detailed studies of the histology of distraction osteogenesis. Some unusual features of the endochondral ossification that occurs during the rapid transition of cartilage to bone in the regenerate were observed. Histological staining techniques together with immunohistochemistry and nonradioactive in situ mRNA hybridization for cartilage and bone-related molecules have been used to document the presence of an overlapping cartilage-bone phenotype in cells of the cartilage-bone transitional region. In those particular areas, some chondrocytes appeared to be directly transformed into newly formed bone trabeculae which are surrounded by bone matrix. Acid phosphatases were found within the cartilage matrix in some of the cartilage/bone transitional regions and type I collagen mRNA and type II collagen protein were found together in some of the marginal hypertrophic chondrocytes. This study indicates an unusual role of chondrocytes in the process of ossification at a distraction rate of 1.3 mm/day in the rabbit. Further direct evidence is required to prove the hypothesis that the hypertrophic chondrocytes may transdifferentiate into bone cells in this model.
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prevention of deformity during limb Lengthening
Clinical Orthopaedics and Related Research, 1997Co-Authors: A H R W Simpson, T N Gardner, Mervyn Evans, G Herling, J KenwrightAbstract:Deformity occurs frequently at the site of distraction during Leg Lengthening and can add to disability. The elastic and nonelastic displacements have been measured in a model that simulates Leg Lengthening in the laboratory. Measurements have been made for different fixator systems. The angulation in the vertical plane that occurs during Leg Lengthening is minimized if the distance between the bone and the fixator bar is kept as small as possible, if three screws are inserted in the proximal and distal bone fragments, and if the peak loads on the fixator are reduced by adjusting the rhythm of distraction. However, even if these precautions are taken, the results show that some fixators designed for Leg Lengthening will fail and lead to deformity at the osteotomy site. This may occur under the repeated cycles of high loads associated with the rises in soft tissue tension that are known to occur in certain groups of patients. This study suggests that deformity can be prevented by the proper selection of a suitable frame and the adjustment of its configuration to meet the loading requirements.
Sasan Tschakoschian - One of the best experts on this subject based on the ideXlab platform.
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lymphangiopathy in neurofibromatosis 1 manifesting with chylothorax pericardial effusion and Leg edema
International Journal of General Medicine, 2013Co-Authors: Josef Finsterer, Claudia Stollberger, Elisabeth Stubenberger, Sasan TschakoschianAbstract:Background This case report documents the affliction of the lymph vessels as a phenotypic feature of neurofibromatosis-1 (NF-1). Methodology Routine transthoracic echocardiography, computed tomography scan of the thorax, magnetic resonance angiography of the renal arteries, and conventional digital subtraction angiography were applied. Comprehensive NF-1 mutation analysis was carried out by fluorescence in situ hybridization analysis, long-range reverse transcriptase polymerase chain reaction, and multiple-ligation probe assay. All other investigations were performed using routine, well-established techniques. Results The subject is a 34-year-old, half-Chinese male; NF-1 was suspected at age 15 years for the first time. His medical history included preterm birth, mild facial dysmorphism, "cafe au lait" spots, subcutaneous and paravertebral fibromas, multifocal tachycardia, atrial fibrillation, and heart failure in early infancy. Noncalcified bone fibromas in the femur and tibia were detected at age 8 years. Surgical right Leg Lengthening was carried out at age 11 years. Bilateral renal artery stenosis, stenosis and aneurysm of the superior mesenteric artery, and an infrarenal aortic stenosis were detected at age 15 years. Leg edema and ectasia of the basilar artery were diagnosed at age 18 years. After an episode with an erysipela at age 34 years, he developed pericardial and pleural effusion during a 4-month period. Stenosis of the left subclavian vein at the level of thoracic duct insertion was detected. After repeated pleural punctures, pleural effusion was interpreted as chylothorax. Reduction of lymph fluid production by diet and injection of talcum into the pleural cavity had a long-term beneficial effect on the chylothorax. Leg edema and chylothorax were attributed to affliction of the lymph vessels by the NF-1. Discussion Lymphangiopathy resulting in impaired lymph fluid flow and sequestration of lymph fluid into the pleural sinus and the Legs may be a rare phenotypic feature of NF-1.
Josef Finsterer - One of the best experts on this subject based on the ideXlab platform.
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lymphangiopathy in neurofibromatosis 1 manifesting with chylothorax pericardial effusion and Leg edema
International Journal of General Medicine, 2013Co-Authors: Josef Finsterer, Claudia Stollberger, Elisabeth Stubenberger, Sasan TschakoschianAbstract:Background This case report documents the affliction of the lymph vessels as a phenotypic feature of neurofibromatosis-1 (NF-1). Methodology Routine transthoracic echocardiography, computed tomography scan of the thorax, magnetic resonance angiography of the renal arteries, and conventional digital subtraction angiography were applied. Comprehensive NF-1 mutation analysis was carried out by fluorescence in situ hybridization analysis, long-range reverse transcriptase polymerase chain reaction, and multiple-ligation probe assay. All other investigations were performed using routine, well-established techniques. Results The subject is a 34-year-old, half-Chinese male; NF-1 was suspected at age 15 years for the first time. His medical history included preterm birth, mild facial dysmorphism, "cafe au lait" spots, subcutaneous and paravertebral fibromas, multifocal tachycardia, atrial fibrillation, and heart failure in early infancy. Noncalcified bone fibromas in the femur and tibia were detected at age 8 years. Surgical right Leg Lengthening was carried out at age 11 years. Bilateral renal artery stenosis, stenosis and aneurysm of the superior mesenteric artery, and an infrarenal aortic stenosis were detected at age 15 years. Leg edema and ectasia of the basilar artery were diagnosed at age 18 years. After an episode with an erysipela at age 34 years, he developed pericardial and pleural effusion during a 4-month period. Stenosis of the left subclavian vein at the level of thoracic duct insertion was detected. After repeated pleural punctures, pleural effusion was interpreted as chylothorax. Reduction of lymph fluid production by diet and injection of talcum into the pleural cavity had a long-term beneficial effect on the chylothorax. Leg edema and chylothorax were attributed to affliction of the lymph vessels by the NF-1. Discussion Lymphangiopathy resulting in impaired lymph fluid flow and sequestration of lymph fluid into the pleural sinus and the Legs may be a rare phenotypic feature of NF-1.
Carol Hasler - One of the best experts on this subject based on the ideXlab platform.
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intramedullary Leg Lengthening with a motorized nail
Acta Orthopaedica, 2011Co-Authors: Andreas H Krieg, Ulrich Lenze, Bernhard M Speth, Carol HaslerAbstract:Background and purpose In the last decade, intramedullary limb Lengthening has become a viable alternative to traditional external systems. We retrospectively analyzed the use of an intramedullary motorized nail (Fitbone) in a consecutive series of 32 patients. Patients and methods During the period September 2006 to December 2008, 32 consecutive patients with a median age of 17 (IQR: 15–19) years were treated with a fully implantable, motorized intramedullary Lengthening device (Fitbone). The median Leg length discrepancy was 35 (IQR: 30–44) mm at the femur (n = 21) and 28 (IQR: 25–30) mm at the tibia (n = 11). Results Leg Lengthening was successful in 30 of 32 cases, with no residual relevant discrepancy (± 5 mm). No intraoperative complications were observed. The consolidation index was significantly different (p = 0.04) between femoral Lengthening (mean 35 days/cm) and tibial Lengthening (mean 48 days/cm) but did not depend on age older/younger than 16 or previous operations at the affected site. 3 pr...
John A Kanis - One of the best experts on this subject based on the ideXlab platform.
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new bone formation during Leg Lengthening evaluated by dual energy x ray absorptiometry
Journal of Bone and Joint Surgery-british Volume, 1993Co-Authors: K S Eyres, M J Bell, John A KanisAbstract:We measured the extent and rate of new bone formation over an 18-month period before, during and after the Lengthening of ten Leg segments in six patients aged between 8 and 18 years, using dual-energy X-ray absorptiometry (DEXA). New bone formation could be identified within one week of the start of distraction. As Lengthening proceeded, the bone density of the gap fell, reaching minimum values at the time of maximal distraction. Consolidation of the regenerating bone was started 1 to 2 weeks later in the tibia, and 2.5 to 3.0 weeks later in the femur. The rate of mineral accretion in new bone was significantly greater in the tibia than in the femur (16 +/- 1.86%/month, and 11 +/- 1.1%/month respectively; mean +/- SEM). There was significant osteoporosis distal to the osteotomy, more in the tibia than in the femur, particularly on the side of the fixator. The bone mineral density of the distal segment remained low at the time of fixator removal (44.2 +/- 5.58% and 61.0 +/- 4.2% of the control values at the tibia and femur respectively) and was only partially reversed by subsequent weight-bearing. We conclude that dual-energy X-ray absorptiometry provides an objective and quantitative assessment of new bone formation during Leg Lengthening. The technique also allows the measurement of the distraction gap and the assessment of Leg alignment from the high-resolution images. Its use may decrease the requirements for conventional radiography.