PURPOSE: We have used a hybrid fixation, in which DynaExtor(R) and Ilizarov rings are connected each other with special connectors. Here, we report upon the technical tips learned and the clinical outcomes of the first twenty five consecutive cases treated using this method. MATERIALS AND METHODS: Between May 1997 and December 1999, 25 patients were treated using hybrid fixation aimed at simple lengthening (8 patients), concomitant deformity correction and lengthening (12), deformity correction alone (3), and fracture fixation (2). RESULTS: In the group requiring simple lengthening, the healing index (H.I.) was 38.3 day/cm (23.6-66.8 day/cm). For concomitant deformity correction and lengthening, the mean amount of angular correction was 33.8degrees (15-75degrees) and the length gain, 4.7 cm (2.2-8.9 cm). For deformity correction alone, the amount of angular correction was 50.1degrees (15-120degrees). For fracture fixation, the mean external fixation time was 59.5 days (26-93 days). Complications included mild pin-tract infection in 8 patients, a temporary stiff joint in 5, and equinus of the foot and delayed union in one patient each. CONCLUSION: The DynaExtor(R) hybrid-fixation system is an effective and convenient method that can be selectively applied to cases that need deformity correction, lengthening, or fixation of the long bone.
Bone Lengthening ; Congenital Abnormalities ; Foot ; Fracture Fixation ; Humans ; Joints

We investigated the effect of tibial lengthening by means of callotasis on enchondral growth of the tibia, Ninety-nine 5-week-old immature rabbits were separated into five groups according to the percentage of lengthening : GroupI(10% lengthening), Group II (20% lengthening), Group III (30% lengthening), Group IV (40% lengthening), Group V (sham operation without lengthening). Osteotomy of the tibia and fibula was made at the proximal metaphysiodiaphyseal junction. Distraction was started at the rate of 0.25mm twice a day from the third postoperative day to simulate the currently accepted callotasis. In Group I, II, and V, there two were no statistically significant differences in the growth rates between the left operated and the right normal tibiae. In contrast, the ratios of left over right tibial length decreased significantly in Group III (4.8%), and Group IV (8.6%) at the completion of lengthening(p < 0.0001), and remained decreased until near skeletal maturity. Histomorphometric study revealed that, in Group III and IV, there were statistically significant decreases in the ratios of the thickness of left over night tibiae at both proximal and distal growth plate(p < 0.0001). Immunohistochemical study also revealed that, in Group III and Group IV, the ratios of left over right bromodeoxyuridine(BrdUrd) labeling percentage decreased significantly (p < 0.0001). In summary, when the tiba was lengthened 30% or more, retardation of enchondral growth was evident, which persisted from the time of completion of lengthening to near skeletal maturity. It is postulated that unphysiologically increased pressure on the growth plate due to excessive bone lengthening may be closely related with the inhibition of enchondral growth.
Bone Lengthening ; Fibula ; Growth Plate ; Osteogenesis, Distraction ; Osteotomy ; Rabbits ; Tibia

We investigate the serial change of the bone density of the lengthening sites in distraction osteogenesis in long bone lengthening of the lower extremity by measuring the pixel value of the PACS(Picture Archiving Communication System). The purpose of this study was to find the clinical implication of the pixel value in PACS in the distraction osteogenesis. The number of the distraction sites were 22 in tibia and 16 in femur. The average distraction length was 4.5cm ranged between 2.1cm and 7.0cm in femur, 4.1cm ranged hetween 1.9cm and 6.8cm in tibia. When the image were sent to the PACS workstations, they were directly interfaced to the workstation without any processing. The absolute and the relati ve pixel values of cortical bones of the original and the lengthening sites repr sented in workstation of PACS were obtained by average value measuring 3 times by 3 different persons. The average absoiute pixel value of the original cortical bone near distraction site was not significantly changed, maintaining 575+/-6 in femur, and 570+/-7 in tibia. The absolute pixel vaIues in AP and lateral view were not significantly changed until 6 week/cm, but rapidly increased after 7 week/cm hoth in the tibia and the femur. The relative pixel value of the lengthening sites were more than 95% in three of the four cortices at the time of the removal of the external fixators. in conclusion, the pixel value of the PACS can be a rapid, simple and easy method for detection of the change of the bone density in distraction osteogenesis.
Bone Density* ; Bone Lengthening* ; External Fixators ; Femur ; Humans ; Lower Extremity* ; Osteogenesis, Distraction* ; Tibia

OBJECTIVETo study the two-axis parallel method in bone lengthening.

METHODSAmong 54 patients (male 28, female 26, mean age 22) who performed tibial lengthening by metaphyseal osteotomy using two-axis parallel method, 26 patients were poliomyelitis sequelae, 13 patients were inequality in limb length after trauma, 4 patients were achondroplasia, 6 patients were genetic short stature, 1 patient was maculatum disease complicated with leg length discrepancy, 4 patients were pituitary dwarfism.

RESULTSAll the patients were followed up and the duration ranged from 18 months to 45 months, with an average of 24.5 months. All patients had bone lengthened. The maximum increase of limb length was 12 cm and the minimum increase was 5 cm, averaged 6.2 cm. One patient had foot drop, 2 patients had foot drop complicated with strephexopodia, 1 patient had serious pinhole infection, and 1 patient had delayed union of the bone.

CONCLUSIONThe two-axis parallel method tibial lengthening by metaphyseal osteotomy can reduce postoperative complications and simplify the operative procedure, which is an ideal method for bone lengthening.

Adult ; Bone Lengthening ; methods ; Female ; Humans ; Male ; Middle Aged ; Osteotomy ; methods ; Tibia ; surgery

Distraction osteogenesis is a technique of bone lengthening by gradual movement and subsequent remodeling. Distraction forces applied to bone also create tension in the surrounding soft tissues, distraction histiogenesis. Distraction osteogenesis is used to correct facial asymmetry, such as patients with hemifacial microsomia, maxillary or mandibular retrusion, cleft lip and palate, alveolar defect and craniofacial deficiency. Hemifacial microsomia is characterized by unilateral facial hypoplasia, often with unilateral shortening of the mandible and subsequent malocclusion. This report describes two cases of hemifacial microsomia(type IIB). In these two cases, distraction osteogenesis was used to correct a facial asymmetry. Two patients underwent unilateral mandibular distraction osteogenesis of ascending ramus of the mandible with extraoral devices. Successful distraction osteogenesis was achieved in the patients with hemifacial microsomia.
Bone Lengthening ; Cleft Lip ; Facial Asymmetry ; Goldenhar Syndrome* ; Humans ; Malocclusion ; Mandible ; Osteogenesis, Distraction* ; Palate ; Retrognathia

PURPOSE: To evaluate changes in the sciatic nerve of rabbits according to the degree of femoral lengthening. MATERIALS AND METHODS: Acute and gradual bone lengthening of the femur were performed after osteotomy, using external fixators in 36 rabbits of both sexes weighing 2, 500 gm. According to the lengthening amount and the percent increase (PI), 21 rabbits (acute lengthening) were divided into seven subgroups and 15 rabbits (gradual lengthening) into five subgroups. A nerve conduction study, light microscopic and electromicroscopic analysis of the sciatic nerve were performed. RESULTS: Acute femoral lengthening between 0.5-0.75 cm (PI= 6-9%) caused remarkable electrophysiologic and microscopic changes in the sciatic nerve, gradual lengthening between 0.75-1.0 cm (PI= 9-13%) induced significant electrophysiologic changes, and gradual lengthening between 1.0-1.5 cm (PI=13-19%) caused significant pathologic change. CONCLUSION: Gradual bone lengthening is safer for nerves than acute bone lengthing because of its safety margin, in terms of PI, is double that of acute bone lengthening. The results in this study provide helpful data to those in human nerve research upon the effects of acute and gradual bone lengthening.
Bone Lengthening ; External Fixators ; Femur ; Humans ; Neural Conduction ; Osteotomy ; Rabbits* ; Sciatic Nerve*

The purpose of this experiment was to determine the effect of dividing the periosteum circumferentially on the growth of long bones and the effect of partial division of the periosteum on the formation of angular deformity of growing bones and to investigate the tethering effect of the periosteum on the epiphyseal plate as its possible mechanism. One hundred twenty rabbits, one-month old with average weight of 570g, were divided into four groups. In the first group, the periosteum of the right distal femur was completely divided circumfer- entially; in the control group, the medial aspect of the right distal femur was surgically approached but the periosteum was not divided, in the third group, the medial half of the peristeum of the right distal femur was divided transversely; in the fourth group, the medial half of the periosteum was divided and resutured. Following the operation, X-rays were taken every two weeks until twelfth week and then at twentieth week and the length of the femur and the physis-shaft angle were measured. l. After complete circumferential division of the periosteum, the ratios of right over left femoral length before operation, and two, four, six, eight, ten, twelve, and twenty weeks postoperatively, were 100.0±0.0%, 102.1±0.1%, 102.±0.0%, 102.9±0.0%, 103.5±0.0%, 103.6±0.0%, 103.5±0.0%, and 103.5±0.0%, respectively. The overgrowth was most conspicuous during the first two weeks. On the other hand, in the control group there was slight overgrowth, but this was not statistically significant. 2. After partial division of the periosteum, the physisvhaft angles before operation, and two, four, six, eight, ten, twelve, and twenty weeks postoperatively, were 91.0±1.2, 87.8±2.5,84.4±2.4, 83.1±3.2, 84.2±3.5, 86.4±2.3, 86.2±2.3, and 86.8±1.9, respectively. The valgus deformity was induced most conspicuously during the first four weeks, whereas partial correction of the de- formity took place between the eighth and tenth week postoperatively. After repair of the partially divided periosteum, only 0.9 of angular deformity was observed at sixth week, but this became statistically insignificant at tenth week as were in the complete division and control groups. 3. Histologically, no difference was observed in the cartiage cells of the epiphyseal plate and the bony trabeculae of the metaphysis between the control group and other groups. The divided periosteum regenerated at the ninth week, this being same also in the repaired group. There was no statistical difference in the thickness of the epiphyseal plate between the operated femur and the opposite normal femur in the completely divided group, this being same in the control group. Threr was also no statistical difference in the thickness of the epiphyseal plate between the medical and lateral halves in the partially divided group, this being same in the repaired group. Based on these results, the investigator was able to draw following conclusions. 1. In the growing long bone, complete circumferential division of the periosteum near the epiphyseal plate results in stimulation of growth and lengthening of bone. 2. Partial transverse division of the periosteum results in asymmetrical overgrowth, inducing an angular deformity. 3. It is suggested that the mechanism of overgrowth following division of the periosteum lies in the removal of the tethering effect of the periosteum. These findings may bear clinical implications on leg length inequality and angular deformities following certain fractures and epiphyseal injuries during growth period.
Bone Lengthening ; Congenital Abnormalities ; Femur ; Growth Plate ; Hand ; Humans ; Leg Length Inequality ; Periosteum ; Rabbits ; Research Personnel

We, at Department of Orthopedic Surgery, College of Medicine, Pusan National University, applied epiphyseal distraction as a method of limb lengthening, using unilateral one-plane pin fixator(ORTHOFIX) and bilateral multi-plane ring fixator(SEQUOIA) to three children with limb length discrepancies and angulation deformity due to injury of epiphyseal plate, and obtained following results. l. At first case, on whose distal femoral physis, bone bridge occupied about 20% of total epiphyseal plate and distributed mainly on the lateral side. At 10 days of distraction, epiphysiolysis occurred from the lateral side at first and angulation deformity was corrected. Epiphysiolysis on the medial side of physis appeared apparently after 60mm distraction. Bone lengthening of 4.2cm and correction of 25 valgus deformity were achieved after 72mm distraction for about 10 weeks. The percentage of increase in the initial length achieved was 11.67% and healing index was 27.86. 7 months later, loss of lengthening of 2.7cm was observed and it was considered that this was due to relatively short corticalization phase. 2. At second case, on whose distal tibial physis, bone bridge occupied about 40% of total epiphyseal plate and distributed on the medial side. At 10 days of distraction, epiphysiolysis occurred on the medial side of the epiphyseal plate, but not on the lateral side and instead of further lengthening, valgus deformity of the ankle appeared. It was thought that asymmetric distraction was attributed to the difference between the force applied on the medial side and that applied on the lateral side of the epiphyseal plate by unilateral one-plane pin fixation. 3. At third case, on whose distal tibial physis, bone bridge occupied about 75% of total epiphyseal plate. No epiphysiolysis occurred. there was a difficulty in observation of epiphysiolysis because ring fixator was overlapped with the epiphyseal plate on radiographs.
Ankle ; Bone Lengthening ; Busan ; Child ; Congenital Abnormalities ; Epiphyses, Slipped ; Extremities ; Growth Plate ; Humans ; Methods ; Orthopedics

Limb lengthening is now an accepted form of correcting limb length inequality. It is, however, associated not infrequently with a variety of complications including pheripheral nerve palsies. Such nerve dysfunction is obviously dependent on the velocity and amount of bone lengtening. In this experiment, the author attempted to determine the safe limits of the velocity and amount of bone lengthening by measuring somatosensory evoked potential (SSEP). The tibiae of 96 rabbits, weighing from 1.5 to 1.6kg, were osteotomized; in Group I, the tibiae were lengthened 0.35mm per day once daily;in Group II, 0.7mm per day; in Group III, 1.05mm per day; and in Group IV, 1.4mm per day. Several rabbits were subjected to the study weekly until, six weeks postoperatively in Group I, five weeks postoperatively in Grup II, four weeks postoperatively in Group III, and three weeks postoperatively in Group IV. The following results were obtained: 1. Preliminarily, in order to verify the possible difference between the right and left tibiae, Pl latency and amplitude were measured in 18 rabbits. Paired t-test revealed no statistically significant difference between the two (p>0.05). The amplitude manifested more individual variation than the Pl latency. 2. As lengthening progressed, the Pl latency gradually increased, whereas the amplitude decreased. The higher the percentage of lengthening to the original tibial length, the more marked the changes in both the Pl latency and amplitude. 3. As lengthening progressed, significant changes were observed earlier in the amplitude than in the Pl laterncy. 4. Significant changes in the amplitude were observed when lengthening reached 12.2% of the original tibial length in Group I (0.35mm/day) and 10.5% in Group IV (1.4mm/day). Significant changes in the Pl laterncy were observed when lengthening reached 17.8% of the original length. It is concluded that somatosensory evoked potential is an effective method of detecting early and preventing neurological complications in bone lengthening. Somatosensory evoked potential is a clinically feasible technique. It is expected that the finding of study may serve as a useful guideline for detecting the safe limits of velocity and amount of bone lengthening.
Bone Lengthening ; Evoked Potentials, Somatosensory ; Extremities ; Methods ; Paralysis ; Rabbits ; Socioeconomic Factors ; Tibia

The purpose of this study is to investigate the effect of lengthening in long bones on the articular carilage by observing the changes in articular cartilage, Fifty-seven rabbits of growing period were divided into four lengthening groups; 5%, 10%, 20%, and 30%. Lengthening by callotasis that was done on the left tibiae and right tibiae were used as control. After lengthening histopathological, histochemical and autoradiographic studies were done on the proximal and distal tibial articular cartilages. That following observations were made. 1. As compared with controls, statistically significant degenerative changes were noted in proximal and distal articular cartilages when the tibiae were lengthened 10% or more. 2. In the proximal joints, the changes were significant between 10% and 20% lenghtening groups, but not between the 20% and 30% lengthening groups. 3. In the distal joints, the changes were significant. Not only were there between 10% and 20% lengtening groups but also there were between 20% and 30% lengtening groups. 4.Degenerative changes were frequently found in the intermediate zone between the periphery and the center, where most of the weight is borne.5. Decrease in matrix content of degenerated articular cartilage was noted by histochemical studies using safranin-0 and Alcian-blue.6. Autoradiography with S04 was done to quantitate matrix content of articular cartilage, and the mean uptake ratio of the articular cartilage was slightly higher than others in the 30% lengthening group. This esuggest decreased matrix synthesis, but no statistical significance was found. Following conclusion were drawn from above observations. 1. In rabbits, tibial lengthening tended to cause microscopic degenerative changes, and the changes begun to appear when the tibiae were lengthened 10% or more. 2. When lengthened over 20%, the changes became more pronounced in the distal joint than in the proximal joint.
Autoradiography ; Bone Lengthening ; Cartilage, Articular ; Joints ; Leg ; Osteogenesis, Distraction ; Rabbits ; Tibia