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PubMed1995

[Bone lengthening: application to the mandible. Review of the literature].

In literature, the authors demonstrate that progressive distraction osteogenesis, according to the Ilizarov method, is applicable to the mandible. Mandibular distraction is achievable through external approach or through oral approach. Further experimental and clinical studies will be necessary to define the most stable apparatus and the best indications that are currently hemifacial microsomia and facial asymmetry associated with T.M.J. ankylosis.

Animals↗
PubMed2004

Distraction-resisting force during tibial diaphyseal lengthening and consolidation--a study on a rabbit model.

BACKGROUND: Distraction-resisting force is generated in the soft tissues and callus during limb lengthening. Monitoring this force may offer a method of studying the behaviour of soft tissue and detecting the distraction osteogenesis related problems, and help to prevent complications. Changes in the post distraction period have not been previously investigated and there are no reports on the contribution of gastrocnemius to the distraction-resisting force. METHODS: Sixteen immature New Zealand White rabbits underwent 30% (left) tibial diaphyseal lengthening at a rate of two 0.4 mm increments per day. Using an instrumented bilateral fixator, the passive distraction-resisting force and the contribution made by gastrocnemius were measured at the end of lengthening and 5 weeks after lengthening. FINDINGS: The distraction-resisting force at the end of lengthening (mean 44 N (SD 10)) was statistically higher (p < 0.01) than that five weeks after lengthening (mean 20 N (SD 8)), so was the contribution of the gastrocnemius to the force (mean 11 N (SD 5 N) or 25% (SD 7) at the end of lengthening and 3 N (SD 1) or 13% (SD 5.2) five weeks later). INTERPRETATION: The callus rather than the surrounding muscles generates most of the passive DRF and its share of the force increased during consolidation period.

Animals↗
PubMed2002

Induced osteogenesis by periosteal distraction.

PURPOSE: The purpose of this project was to evaluate a novel technique for inducing osteogenesis through periosteal distraction in a rabbit model. MATERIALS AND METHODS: A periosteal distraction device was rigidly fixed to the lateral surface of the mandible in 10 adult rabbits. Periosteal distraction was started 7 days after placement of the periosteal distraction device. The periosteum was distracted 7 mm over 15 days. The unoperated, contralateral side of the mandible served as the control. The animals were killed at postoperative days 28, 35, 42, and 56. The specimens were then fixed, decalcified, and stained with hematoxylin and eosin. Histologic examination and histomorphometric analysis were performed on all specimens. RESULTS: Nine of 10 periosteal distraction devices remained rigidly fixed to the lateral surface of the mandible. On postoperative day 28, the histologic specimen from the experimental side showed periosteal proliferation and an increase in the number of osteoblasts. On postoperative days 35, 42, and 56, the experimental side showed an increase in the number of osteocytes per unit area, collagen fibers parallel to the vector of distraction, islands of osteoblasts surrounded by newly formed bone, and maturation of bone. An average of 2.86 +/- 0.56 mm of new bone height was formed. CONCLUSION: We report on a novel technique for generating bone by periosteal distraction. Our histologic analysis showed proliferation of the periosteum, an increase in the number of osteoblasts and osteogenesis.

Animals↗
PubMed2003

[The possibility of midface skeleton protraction: an experimental study in dogs].

OBJECTIVE: To probe the feasibility of a new technique of sutural distraction osteogenesis for midface hypoplasia repair. METHODS: A protraction system was developed, which consisted of three parts: a rigid external framework, a bone hook, and the elastic band. Four 12-week mongreal dogs were randomly assigned into two groups: the control (n = 1) and the experimental groups (n = 3). Four pairs of titanium bone markers were fixed on either side of the bone sutures of all animals. The experimental group was fitted with a distraction device, through which a forward elastic force was exerted for 1 month. Clinical observations and X-ray examinations were performed at the beginning and the end of distraction. New bone specimens were examined histologically. RESULTS: All the animals in the experimental group showed progressively forward movement of the maxilla and manifested class II occlusion at the end of the experiment. The distance increase between each pair of bone markers showed that premaxilla advancement was more than that of the maxilla. The next was zygoma. There was no obvious difference between the control and the experimental group in terms of the basilar-maxillary angle and counterclockwise rotation. Theer was active osteogenesis in the sutures, especially in premaxilla-maxillary sutures. The number of osteoblasts and fibroblasts increased dramatically and new bone formation was found at the edge of the suture. CONCLUSION: This technique can create effective advancement of the maxilla. The direct force can avoid counterclockwise rotation of the maxilla during distraction.

Animals↗
PubMed1992

Recent advances in limb lengthening. Part II: Biological advances.

The most important recent advance in limb lengthening is the recognition that bone will regenerate, under appropriate conditions, within the gap of an osteotomized bone. Although Codivilla recognized this phenomenon, bone formation was inconsistent in his patients. Optimal distraction osteogenesis requires a knowledge of osteotomy techniques, length of latency period, rate and frequency of distraction, and mechanical effects of loading.

Bone Lengthening↗
PubMed2000

Craniofacial shortening by contraction osteogenesis: an experimental model.

Application of gradual external forces to correct craniofacial deformities challenges many procedures in conventional craniomaxillofacial surgery. Distraction osteogenesis is replacing traditional osteotomies for correction of patients with craniomaxillofacial deficiencies. However, the reverse concept, contraction osteogenesis, has yet to be established for patients with craniomaxillofacial excesses. The purpose of this investigation is to demonstrate the contraction osteogenesis phenomenon applied in a controlled animal model during the craniofacial growth period. Twenty-six 26-day-old rabbits were assigned to one of four groups: 0, control; 1, pin control (pin insertion); 2, no contraction (pins and contraction device application, without active contraction); and 3, contraction (pin insertion, contraction device application, and active contraction). An external fixator was placed across the incisive-maxillary suture, and the effects after 4.5 weeks of contraction at a rate of 0.5 mm twice a week were compared with control groups. The results were assessed by craniometric and cephalometric measurements and by histologic examination. Gross alterations were evident in the contraction group, characterized by midface anteroposterior shortening, maxillary regression, snout deviation, and anterior crossbite. Histologic examination of the contraction group demonstrated a significant increase in osteoblastic activity. Contraction osteogenesis is a new treatment concept in craniofacial development and may offer therapeutic opportunities for shortening skeletal structures without the need of osteotomies, thus taking advantage of the potential of craniofacial growth and remodeling.

Animals↗
PubMed1999

Temporary muscle weakness in the early phase of distraction during femoral lengthening. Clinical and electromyographical observations.

Limb lengthening by distraction osteogenesis has a high complication rate. Much of the response of muscle and nerve to distraction is still unknown. Thirteen children, mean age 12.6 yr (8.4-17.3) were surgically treated by the Ilizarov procedure for acquired and congenital femoral limb-length discrepancy. All children showed a decrease in muscle strength in the quadriceps, shortly after the operation, followed by an improvement before distraction started. After an elongation in the early phase of distraction (1 to 2 cm), muscle weakness was again observed and the muscle strength gradually increased after ending of distraction. To provide an explanation for this clinical observation, in one patient (limb lengthening of 4.1 cm) muscle strength measurements were extended with investigations of Hoffman (H) reflex of m. vastus medialis and determination of muscle-fiber conduction velocity of m. vastus lateralis by using the invasive method (IMFCV). The examinations were performed every two weeks during 20 weeks and 12 weeks after removing the cast. A severe decrease in muscle strength of the corrected limb was found after 1.2 cm of distraction with a recovery in muscle strength before lengthening was ended. EMG study showed the same tendency. Denervation was observed as evidence by positive sharp waves and reduced IMFCV findings. Evidence for reinnervation before lengthening was ended, was found by an increased range of velocities consisting of a combination of slow potentials and gradual increase of the velocity of reinnervated fibers (increased Fast/Slow ratio). The latencies of M waves and H-M interval from both legs separated as well after 2.25 cm of distraction. At the end of the follow-up period, the H-M interval reached the preoperative value. It is suggested that these neurogenic changes are an effect of axonal dysfunction and the local effect due to intraoperative trauma and stretching might affect nerve blood flow adversely.

Adolescent↗
PubMed1996

[Ultrasound follow-up of callus distraction--an alternative to roentgen diagnosis?].

In a prospective study 20 patients were regularly monitored with sonograms in four planes and radiographs during distraction osteogenesis of the lower limb. Ultrasonography is more sensitive than radiography in identifying new bone formations during distraction, in measuring the length of the distraction gap, and in detecting early bone healing complications, and can therefore reduce the need for radiographs. Radiographs are necessary to assess the time of fixator removal and the axis of the leg.

Bone Lengthening↗
PubMed1996

[Ultrasound follow-up of callus distraction of the tibia. Technique, possibilities and limits].

In a prospective study 20 patients were monitored with serial sonograms and radiographs during distraction osteogenesis at the lower limb. All sonograms were obtained in four planes using a 7.5 MHz transducer. The distraction gap was seen as a sonolucent area in all patients after corticotomy. At an average of 20.7 (14-28) days after the beginning of the distraction, echogenic foci occurred and showed increasing longitudinal alignment with further distraction. Radiographical signs of beginning mineralization were seen an average of 48.3 days after the start of the distraction. Exact measurement of the distraction gap was possible in all patients during lengthening. Bone healing complications and hematoma could be detected by ultrasound. A rapid increase of bone mineralization was seen after the distraction was stopped. With increasing cortication of the regenerate bone, sonograms showed a hyper-reflecting solid line so that further mineralization and the time of removal of the fixator could not be assessed by ultrasound. Ultrasound is more sensitive than radiography in identifying new bone formation during distraction, measuring the length of the distraction gap, and detecting early bone-healing complications and can therefore reduce the need for radiographs.

Adult↗
PubMed2006

Effects of systemic and local administration of recombinant human IGF-I (rhIGF-I) on de novo bone formation in an aged mouse model.

UNLABELLED: DO was used in an aged mouse model to determine if systemically and/or locally administered rhIGF-I improved osteoblastogenesis and new bone formation. Local and systemic rhIGF-I treatment increased new bone formation. However, only systemic delivery produced measurable concentrations of rhIGF-I in the circulation. INTRODUCTION: Human and rodent research supports a primary role for IGF-I in bone formation. Significant roles for both endocrine and paracrine/autocrine IGF-I have been suggested for normal osteoblastogenesis and bone formation. We have assessed, using a mouse model of distraction osteogenesis (DO), the impact of continuous administration of recombinant human (rh)IGF-I, delivered either locally to the distraction site or absorbed systemically, on bone formation in an aged mouse model. MATERIALS AND METHODS: DO was performed in aged mice (18-month-old C57BL/6 male mice), which were distracted at 0.15 mm daily. At the time of osteotomy, miniosmotic pumps were inserted subcutaneously to (1) deliver vehicle or rhIGF-I subcutaneously for systemic delivery or (2) deliver vehicle or rhIGF-I directly to the newly forming bone through infusion tubing routed subcutaneously from the pump to the distraction site. Serum concentrations of mouse IGF-I, human IGF-I, and osteocalcin were determined at the end of the study. RESULTS: New bone formation observed in DO gaps showed a significant increase in new bone formation in rhIGF-I-treated mice, irrespective of delivery route. However, detectable levels of human IGF-I were found only in the serum of animals receiving rhIGF-I systemically. Osteocalcin levels did not differ between controls and rhIGF-I-treated groups. CONCLUSIONS: Locally and systemically delivered rhIGF-I both produce significant increases in new bone formed in an aged mouse model in which new bone formation is normally markedly impaired, suggesting that rhIGF-I may improve senile osteoporosis. Because systemic administration of IGF-I can result in untoward side effects, including an increased risk for cancer, the findings that locally delivered IGF-I improves bone regeneration without increasing circulating IGF-I levels suggests that this delivery route may be preferable in an at-risk, aged population.

Aging↗
PubMed2001

Skeletal effects of developmental lead exposure in rats.

To identify possible direct and indirect mechanisms underlying the effects of lead on skeletal growth, 3 studies were conducted. In the first study, 1 male and 1 female pup/litter (n = 5 litters), were exposed ad libitum to 0, 825, or 2475 ppm lead acetate in the drinking water from gestational day 4 to euthanasia on day 55. Tibial strength was tested by 3-point bending and plasma levels of vitamin D metabolites were measured. A dose-dependent decrease of the load to failure was demonstrated but only in male pups. No differences in plasma levels of vitamin D metabolites were observed. In the second study, conducted to test if hormone treatment would attenuate the lead deficits, male and female pups were exposed to 0 or 2475 ppm lead acetate and then, from 30-60 days of age, received either saline vehicle, L-dopa, testosterone (males only), dihydrotestosterone (DHT, males only), or estradiol (females only). Lead exposure significantly reduced somatic growth, longitudinal bone growth, and bone strength during the pubertal period. Sex steroid replacement did not restore skeletal parameters in lead-exposed rats. L-Dopa increased plasma insulin-like growth factor 1 (IGF(1)) concentrations, rates of bone growth, and bone strength measures in controls while having no effect in lead-exposed pups. The third study was conducted at 100 days of age, when endocrine parameters have been shown to be normalized, to test for effects of lead exposure on bone formation during tibial limb lengthening (distraction osteogenesis, DO). Both DO gap x-ray density and proximal new endosteal bone formation were decreased in the distraction gaps of the lead-treated animals (p < 0.01). In conclusion, lead exposure reduced somatic growth, longitudinal bone growth, and bone strength during the pubertal period, and these effects could not be reversed by a growth hormone (GH) axis stimulator or by sex-appropriate hormones. Finally, lead exposure appears to specifically inhibit osteoblastogenesis in vivo in adult animals.

Animals↗
PubMed2005

[Clinical implication of bone regeneration in oral surgery].

Bone augmentation or the alveolar ridge augmentation procedure is inevitable for functional and esthetic prosthetic oral rehabilitation. In this article, conventional alveolar ridge augmentation methods are clinically demonstrated and are reviewed with reference to literature. In addition, distraction osteogenesis (DO), which has drawn considerable attention as a regenerative medicine, was clinically demonstrated. Then, the conventional augmentation methods and distraction are compared. Indications, advantages, and disadvantages of conventional augmentation methods including bone grafts, guided bone regeneration (GBR) and GBR with titanium micromesh (TIME technique) are demonstrated. Next, the mechanisms, indications, and advantages of DO are demonstrated and compared with conventional methods. Although conventional augmentation methods are well established, there are some problems including donor site morbidity and risks of wound dehiscence and infection. DO seems to have advantages compared to conventional augmentation methods. However, there still have some clinical problems such as difficulty in vector control and technique sensitivity. For less morbidity and better efficacy in alveolar ridge bone augmentation, tissue engineering offers potential in the future. However, further basic and clinical study will be necessary for clinical application.

Alveolar Ridge Augmentation↗
PubMed1989

Local bone transportation for treatment of intercalary defects by the Ilizarov technique. Biomechanical and clinical considerations.

Ilizarov applied revolutionary methods for salvaging limbs with severe congenital, posttraumatic, or other acquired deformities. His methods, which use a universal system of ring external fixators with tensioned transosseous wires, were developed over the past 35 years at his institute in Kurgan, USSR. These noninvasive techniques have proved successful in over 300,000 patients (adults and children) treated for bone shortening and intercalary deficiency, angulatory and rotational malalignment, active infection, ischemia, joint contractures, and nonunions. Bone transportation involves moving a free segment of living bone to fill intercalary bone defects with vital bone. The trailing end of the transport bone segment maintains continuity with the host bone surface by distraction osteogenesis. The leading end of the transport bone segment fuses to the target bone surface by transformational osteogenesis. The small diameter of the transosseous wires contributes to better patient tolerance over the prolonged treatment times required for gradual distraction at 1 mm per day.

Biomechanical Phenomena↗
PubMed2004

Predicting duration of Ilizarov frame treatment for tibial lengthening.

AIM: To predict duration of treatment for tibial lengthening, as a function of target length increase. METHOD: Review of case notes and radiographs of patients undergoing Ilizarov method of tibial distraction osteogenesis. RESULTS: In the 27 cases suitable for analysis, the median age was 29.9 years (13.3 to 72.6 years), and the median distraction was 3.5 cm (1.0 to 7.2 cm). A positive linear relationship (r = 0.7) was demonstrated between the distraction length (x, in cm) and the frame duration (y, in days), according to the equation y = 54x + 94. A negative hyperbolic relationship was also demonstrated between rate of bone healing and distraction length (r = 0.6), with distractions over 3.0 cm healing significantly faster than shorter ones (P < 0.03).

Adolescent↗
PubMedDate not supplied

New biomaterials and methods for craniofacial bone defect: chondroid bone grafts in maxillary alveolar clefts.

The purpose of this study was to evaluate autogenous osteogenic marrow within chondroid bone grafts in simulated alveolar defects of mice in order to determine the ability of the graft material to effectively close the cleft from an osseous standpoint and to observe the effect of the grafting procedure. Critical-sized defects were made in the premaxillary bones of male mice using a surgical trephine and a low-speed dental engine as a model of the maxillary alveolar cleft for testing bone-inductive agents. Premaxillary trephine defects were not repaired by fibrous tissue or bone formation 30 days after operation. This nonhealing bony wound of the premaxilla in mice may be useful as a model for studying the effect of bone-inductive agents on the healing of alveolar clefts. Distraction osteogenesis is a recently advanced principle of bone lengthening in which a long bone separated by osteotomy is subjected to slow progressive distraction using an external fixation device. The osteotomy site was surrounded by an external callus consisting of hyaline cartilage. The callus contained a lot of chondroid bone. The transplant bone within chondroid bone was characterized by bone formation and remodeling 30 days after transplantation. Throughout the experiment, our findings demonstrated, for the first time, that the transplant bone that contains chondroid bone may be used clinically in relation to craniofacial bone defects to improve the treatment of bone grafts.

Alveolar Process↗
PubMed1995

Biomechanical analysis of canine bone lengthened by the callotasis method.

The mechanical integrity of tibial bone treated by distraction osteogenesis (callotasis) using an Orthofix external fixator was evaluated in a group of 6 dogs. Diaphyseal corticotomies were performed on Day 0. Distraction was begun on Day 8, at a rate of 0.33 mm every 8 hours. On Day 34, the Orthofix frame was locked. On Day 56, the frames were removed and the dogs were euthanized. Radiographs were taken weekly to assess regenerate bone formation and extent of tibial bone lengthening, which averaged 12 mm (range, 5-20 mm). One dog showed incomplete bony union that was attributed to pin loosening. Torsional testing of lengthened and contralateral control tibiae resulted in spiral diaphyseal fractures. Five of 6 lengthened tibiae bones fractured within the diaphysis, but outside the regenerate area, suggesting that the strength of the lengthened segment exceeded that of the original diaphysis which was exposed to stress shielding by the external fixator. These observations have led to a method to test and evaluate lengthened bone at the time of frame removal and to monitor the effectiveness of this type of technique.

Animals↗
PubMed2001

Lower extremity salvage using a free flap associated with the Ilizarov method in patients with massive combat injuries.

Nine patients with massive combat injuries of the lower extremities were treated with Ilizarov bone transport in conjunction with free muscle flap coverage. In 4 patients soft-tissue coverage was applied first, and distraction osteogenesis was initiated 4 to 6 weeks later. In 3 patients both methods were applied simultaneously, and in 2 patients soft-tissue coverage occurred after distraction. The bones healed well, and all flaps survived. The segmental defects ranged from 8 to 16.5 cm in greatest dimension. The total disability time from initial injury ranged from 16 to 25.5 months. In all patients, full union of the tibia was achieved, and no osteomyelitis occurred. However, in 2 patients the applied flap became depressed, necessitating another flap operation. Despite late treatment in all 9 patients, successful results were obtained. Maintaining the original length of the tibia and providing timely, definitive treatment offer the best outcome for repair of massive injuries of the lower extremities. The Ilizarov transport method, used in combination with muscle flap coverage, represents an effective therapy for repair of massive injury of the lower extremities.

Adult↗
PubMed1990

[Callus distraction by an internal bone transport system in unilateral fixation].

The problem of the treatment of bone defects can be solved by distraction osteogenesis as developed by ILIZAROV. This study shows how the bone transport technique can be adapted to every common external fixator while using a new internal distraction system. In 20 dogs a bone defect of 6 cm was performed at the femur. The femur was stabilized with an unilateral frame. A proximal or distal corticostomized bone fragment (length 2.5 cm) was descended through the bone defect (1 mm day). In 15 dogs a new regeneration of bone was observed. The quality of the regenerated bone depends upon stability of the fixation. In 5 dogs with osteotomy and rapid dislocation of the transported fragment no bone bridging was found.

Animals↗