Closure Of Growth Plate Research Articles

Results of Long-Term Growth Hormone Replacement Therapy in Children: When and How To Treat?

Up to now, the end results of treatment in GH deficiency (GHD) have not been as good as expected. Probably the main cause has been the delay in diagnosing GHD in short children, resulting in a very insufficient height at the onset of puberty. The need for early diagnosis and treatment must be emphasized. This agrees with the well-documented data demonstrating (1) that catch-up growth obtained in any treatable growth disorder has a limited duration, and (2) that the effect of GH replacement, whatever the doses and modes of therapy, is maximal during the first year and wanes during the following years. There are still many questions regarding the appropriate GH replacement dose. The height gain during the first year of treatment has been correlated with the logarithm (decimal or natural) of the dose in several groups of patients receiving GH 3 times/week. The initial dose-response relationship is better with GH 6 times/week. For the following years, no dose/response ratio has been demonstrated, and the final height-to-dose relations are still to be investigated. A dose increase after 2 years or more may improve the growth rate, but also with secondary waning. Thus, long-term prospective dose-response studies are needed. The first period of one such study is presented.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital Spinal Stenosis in Beef Calves in Western Canada

Nineteen calves with a clinical history of posterior weakness or ataxia were examined at necropsy. Dorsoventral narrowing of the vertebral canal and myelopathy were found in the thoracic and lumbar areas of the spinal cord; vertebral metaphyseal growth plates had focal areas of premature closure. Malformation of the cranial base and hydrocephalus were also observed. Shortening of long bones and malformation of long bone epiphyses were prominent findings and were associated with focal premature closure of metaphyseal growth plates. The cause of these lesions is unknown; possible causes, including a maternal deficiency of manganese, are discussed.

Bone ossification and carcass characteristics of wethers given silastic implants containing estradiol.

Administration of growth promotants with estrogenic activity via hastening closure of the growth plate could have an economic impact on lambs because closure results in ovine carcasses being classified as yearlings. Twelve wether lambs approximately 12 mo old were given silastic implants filled with estradiol-17 beta and allotted randomly to be slaughtered 30, 60, 90, or 220 d after implantation to determine time of growth plate closure in relation to date of implanting. Seven comparable wethers not implanted served as controls. Four wethers implanted at 2 mo of age and slaughtered 220 d later also were included. Implanted wethers had serum concentrations of estradiol averaging 13.9 pg/ml over the 220-d implant period; controls averaged 2.7 pg/ml. Estradiol implants increased carcass maturity scores but fat deposition was not altered. Growth plate widths decreased (P less than .05) as wethers grew older and implants were in place for longer periods of time. Metacarpal growth plates in 12-mo-old lambs were completely ossified 220 d after implanting, but control wethers and wethers implanted at 2 mo maintained growth plate widths. Neither metacarpal nor metatarsal bone lengths differed (P less than .05) between control and implanted wethers. Growth plate ossification was not complete until 570 d of age in implanted lambs, even though bone length had stopped increasing by 408 d. Therefore, even though estradiol and other growth stimulants with estrogenic activity increase rate of ossification of the metacarpal growth plate, bone length or mature size is not limited.(ABSTRACT TRUNCATED AT 250 WORDS)

Endocrine and histologic correlates of the dynamics of the metacarpal growth plate in growing rams.

The objective was to study control of mature size by characterizing metacarpal growth plate closure in relation to relevant bone growth-regulating hormones in two breeds exhibiting distinct differences in mature frame size. Thirty-four Suffolk and 34 Dorset ram lambs were slaughtered in pairs within breed at birth, weaning and monthly intervals until 420 d and then bimonthly to 600 d. Plasma growth hormone was depressed to undetectable levels due to the high-energy, ad libitum-fed diet. Plasma insulin-like growth factor-I (IGF-I) rose over the growth period from 116 ng/ml (newborn Suffolk) to a high of 451 ng/ml (420-d Dorset); it appeared to peak at approximately 400 d and then declined to a stable level. Dorsets consistently exhibited higher IGF-I levels. The thyroid hormones exhibited no apparent age association. An age-associated rise was detected for testosterone, but not for estradiol. Mature metacarpal lengths were estimated to be 147.2 and 127.4 mm for Suffolks and Dorsets, respectively. Ninety-five percent of mature length was attained in Suffolks by 226 d and in Dorsets by 165 d. Growth plates, however, did not begin to appear closed until 390 d and closure was not complete in all animals until 480 d, suggesting that metacarpal growth rate was dissociated temporally from growth plate closure. Although growth plate closure likely is controlled by the endocrine system, there were no apparent relationships between circulating hormones and growth plate width, age at closure or zonal divisions within the growth plate, suggesting that the growth plate experiences a very different hormonal environment than what can be measured in the circulating blood.

Effect of Intermittent Lighting and Time of Hatch on Large Broad-Breasted White Turkeys

To determine if intermittent lighting would reduce leg abnormalities in turkeys, males reared in intermittent lighting of 2 h light:4 h dark were compared to toms subjected to a low intensity, step-down lighting program (15-h photoperiod). Also, to determine if housing poults as soon as possible following hatch would affect later production characteristics, effects of four hatching treatments were assessed.Toms in intermittent as compared with low intensity, step-down lighting programs showed a significant reduction in the incidence of leg abnormalities. There were no significant differences in body weight, feed efficiency, mortality, tibial dyschondroplasia lesions, growth plate closure, and tarsometatarsal length and width for the two lighting programs. Toms exposed to intermittent lighting had heavier testes.It is concluded that intermittent lighting can be used in light-tight, environmentally enclosed turkey houses to reduce leg anomalies without affecting other production traits. Under the experimental conditions employed in the present study, there was no advantage to removing poults from incubator trays as they hatched, as hatching treatments had no effect on production traits of either turkey toms or hens.

Familial Diffuse Cystic Angiomatosis of Bone

Twelve cases of diffuse cystic angiomatosis of bone are presented in a family over four generations. The inheritance pattern of the disease appears to be one of an autosomal dominant distribution with no skipped generations and equal sex distribution. Individuals affected are clinically asymptomatic. All blood parameters are normal. Roentgenographically, the lesion occurs throughout the length of long bones and is osteolytic, with a thin sclerotic rim. The cortex of the bone is rarely involved and shows no periosteal reaction. Growth plate closure and remodeling are unaffected. The natural history is of increasing sclerosis, resulting in complete obliteration of the cyst with irregular reactive trabeculations. Although it resembles more serious conditions, the condition can be diagnosed clinically and radiographically, making invasive tests and treatment unnecessary.

Radiological Study of Chondrodysplasia Fetalis in Pigs

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Regeneration of the growth plate.

The occurrence of growth plate regeneration has been doubted. However, in 5 different series of experiments reported between 1950 and 1986 regeneration of injured parts of growth plates in long bones of rabbits and pigs could be demonstrated. The 1st series implied partial X-ray injury of growth plates in rabbits aged 3-6 weeks. The 2nd series implied autotransplantation of the head of the fibula in rabbits aged 10-21 days. The 3rd, 4th and 5th series implied transplantation of autologous fat grafts into provoked defects of growth plates in rabbits and pigs. The findings show that regeneration of a growth plate occurs when a part of it is injured in such a manner that a bone bridge is not formed between the epiphysis and the metaphysis. Regeneration of a plate is much faster in relation to the growth in length of the bone in the rabbit than in the pig. The 1st and 2nd series suggest that regeneration takes place by interstitial proliferation of cells from the germinal layer of the uninjured parts of the plate. Signs of partial regeneration of growth plates have been seen in radiographs after operation for partial closure of growth plates in children.

Dietary Calcium and Metacarpal Growth in Ewes

The effects of excess dietary calcium on bone growth were quantified in 44 ewes fed ad libitum diets that contained one of four levels of dietary calcium (0.37, 0.56, 1.13 and 1.80%) and 0.42% phosphorus. Animals were slaughtered at one of six ages, circulating concentrations of hormones and minerals were measured and bone morphometry was evaluated. None of the diets impaired normal bone growth of the metacarpal as evaluated by overall length, cortical index and growth plate width. Circulating plasma concentrations of calcium and gastrin increased as dietary calcium levels increased, but all values were within the normal range for sheep. Plasma phosphorus was unaffected by the level of dietary calcium. Diet had no affect on T3, T4 or estradiol-17 beta. Age significantly (P less than 0.05) affected the metacarpal length, growth plate width and circulating calcium and phosphorus. The metacarpal in these ewes was 95% of mature length by 172 d of age. Attainment of mature length preceded growth plate closure by slightly over 300 d. These results demonstrate that elevated dietary calcium levels do not adversely influence bone growth and that the presence of an intact growth plate does not infer that further bone growth will occur.

The Place of Threaded Pin Fixation in the Treatment of Slipped Upper Femoral Epiphysis

Pin fixation in the treatment of slipped upper femoral epiphysis was evaluated in 60 patients admitted to the authors' hospital in Melbourne between 1970 and 1978. Forty-three cases were reviewed at an average of eight years following initial treatment. For chronic slips, in situ fixation with pins prevented further slip and promoted growth plate closure. The complication rate was low. Best results were achieved with two or three threaded pins placed into the posteroinferior segment of the femoral head to avoid avascular necrosis. Early upper femoral osteotomy was not required, as considerable bone remodeling occurred even after growth plate closure. In contrast, avascular necrosis was common following treatment of acute, severe slips, even with gentle internal rotation of the leg to reduce the acute component of the slip and pinning.

Effect of Light Intensity, Litter Source, and Litter Management on the Incidence of Leg Abnormalities and Performance of Male Turkeys

Two trials were conducted to evaluate the performance of male turkeys reared in either a low or high intensity lighting regimen. Turkeys were also subjected to the following four litter treatments: 1) hardwood shavings intensively managed; 2) hardwood shavings unmanaged; 3) rice hulls intensively managed; and 4) rice hulls unmanaged.Male turkeys reared in high intensity light (20 lx) had significantly heavier body weights, poorer feed to gain ratios, shorter tarsometatarsal bones, earlier growth plate closure, heavier testes, and were less active during the times of behavioral observations than male turkeys reared in low intensity light (2.5 lx). The width of the tarsometatarsal bone, mortality, and the incidence of leg abnormalities and tibial dyschondroplasia were unaffected by lighting. Poor litter conditions or type of litter (hardwood shavings vs. rice hulls) had no effect on the performance of male turkeys.(u3)

Slipped capital femoral epiphysis in southern Sweden 1910-1982.

This work is based on 532 cases of physiolysis colli femoris (PCF) in southern Sweden from 1910 through 1982. The material was analyzed epidemiologically. Subsets were used for different investigations aimed at surveying the etiology of PCF, and long-term follow-ups were conducted after various methods of treatment. Finally, the short-term results after hook-pinning, a new device, were evaluated. After radiographic examination of anatomic specimens and normal hips, a method to diagnose and grade PCF was developed. The calcar femoral was found to be of constant shape and position and was used as a landmark to which the position of the femoral head was related. The advantage of this method is that it is easy to use and it is able to determine PCF also after growthplate closure. Epidemiologic analysis of the total material revealed large changes during the 20th century. The disease is more common in males than in females, but the male predominance has decreased from about 90 per cent to about 60 per cent during the period of investigation. Mean age at onset of slipping has decreased by about 3 years in males to 12.7 years and by about 1 year in females to 11.8 years. The incidence has followed a periodic pattern with peaks approximately every 20th year. The mean incidence was 6/10,000 in boys and 3/10,000 in girls. Boys living in the country have always been at higher risk than those living in cities. They were also at higher risk of sustaining bilateral slipping. In girls, there is a seasonal variation, with a higher incidence between May and August. The etiologic investigations dealt with hereditary, mechanical, and hormonal aspects. Radiographic examination revealed PCF in about 10 per cent of the first-degree relatives of 50 consecutive patients with PCF. One third of the families had 2 or more members with PCF. This familial accumulation is much higher than shown in earlier investigations based on questionnaires or clinical reports, and higher than expected from the incidence calculations. The growth analysis using the ICP model showed in both sexes an above average body height before puberty. However, at maturity the heights were almost normal, and accordingly the pubertal gain in height was lower than normal. Both the boys and the girls were markedly overweight before puberty and remained so at maturity. The ICP model accords with what is known about hormonal regulation of growth, and the growth abnormalities indicate a disturbed hormonal growth regulation.(ABSTRACT TRUNCATED AT 400 WORDS)

Relationship of high intensity step-up lighting to bone ash and growth plate closure of the tarso-metatarsus in turkeys.

The reduced lameness observed in turkeys reared in a high intensity step-up (HISU) lighting programme as compared to a low intensity step-down (LISD) lighting regimen cannot be explained by differences in the inorganic matrix of the bone, because the proportions of bone ash, bone ash calcium, and bone ash phosphorus did not differ between lighting programmes. At 17 weeks of age, there was a significant difference in the proportion of closed growth plates in males reared on the HISU programme rather than on LISD lighting. These results support the hypothesis that HISU lighting reduces lameness by promoting earlier growth plate closure of long bones.

Epiphyseal Traction to Correct Acquired Growth Deformities

In a canine model with a transepiphyseal distal femoral fracture, varus deformity was corrected and the arrested limb was lengthened using transphyseal traction (turnbuckle). Correction was possible without removing the transphyseal bone bridge operatively. Subsequent growth was not adversely affected in most animals. Based on this study, two patients with significant growth deformities secondary to an enchondroma were treated by epiphyseal traction. Although correction was achieved initially, both lost the length previously gained because of premature removal of the external fixator and/or subsequent early growth plate closure.

The management of elbow instability caused by premature closure of the distal radial growth plate in dogs

ABSTRACTThe clinical and radiographic findings associated with premature closure of the distal radial growth plate are described in 17 dogs. An increase in the humero‐radial joint space with elbow instability and pain was noted in all cases. Radial lengthening procedures were used to treat three dogs, while in seven others, the ulna was shortened to correct elbow instability. Seven dogs were treated conservatively. The results of treatment are discussed in the light of previously published findings.

上腕骨短縮症による肩関節挙上障害の治療経験

A sixteen-year-old female complained of disturbance of the left shoulder elevation and numbness in the left arm. A roentgenogram of the left humerous showed a 7.3cm shortening in its length, deformity of humeral head and the early closure of the proximal growth plate. These findings were presumed to result from a fracture of the proximal humeral epiphyseal plate, which she suffered at the age of ten. The ranges of active motion in the left shoulder were: abduction 80 degrees and flexion 80 degrees. Passively, both ranges of abductuon and flexion were 160 degrees. Neurological abnormalities of the shoulder girdle muscles were not detected in the electromyogram. Because it was concluded that disturbance of shoulder elevation was caused by dysfunction of deltoid muscle due to shortening of the humerus, the left humerus was lengethened by an iliac bone graft with bone block (16mm in length) and a plate fixation at the diaphysis proximal to deltioid insertion. As a result of analysing the effect of humeral lengtening in a simplified simulation of shoulder joint, an increase of 46 degress in shoulder elevation was predicted. One and a half months after operation, the ranges of active motion were: abduction 150 degrees and flexion 150 degrees.

Fracture of the Distal Radial Epiphysis

Wrist deformities developed in ten children secondary to injury of the growth plate and premature closure of the distal radial epiphysis. Premature closure of the growth plate followed epiphyseal compression injuries or repeated forceful attempts at reduction. These injuries should not require repeated reductions in children with epiphyseal remodeling potential of more than two years if the initial reduction achieves apposition of more than 50%. Gross deformity develops if the discrepancy between radial and ulnar lengths is more than 4 mm. Ulnar shortening and correction of the radiocarpal angle, as required, constitute the surgical treatment of choice for growth deformity.

A 30-year experience with bone graft epiphysiodesis in the treatment of slipped capital femoral epiphysis.

A retrospective review was carried out of all cases treated by bone graft epiphysiodesis for slipped capital femoral epiphysis at Children's Hospital Medical Center of Akron between the years 1950 and 1980. Only those cases followed for a minimum of 1 year following treatment were included in the review and evaluated as to their status of avascular necrosis, acute cartilage necrosis, or other complications attendant to the surgical approach. One hundred seventy-six patients representing 207 hips underwent bone graft epiphysiodesis over this 30-year period. One hundred fifty-nine patients representing 185 hips were followed a minimum of 1 year and were included in this study. There were 25 cases of acute slipping representing 26 hips and 134 patients representing 159 hips involved with the chronic slipping process. In the acute group of patients representing 26 hips, there were two cases of avascular necrosis and one case of acute cartilage necrosis. In the chronic group of 159 hips, there were four cases of reslipping, one due to graft resorption, one due to placement of the graft short the growth plate, and two that went on to acute slipping. All cases were salvaged with good results. There was one case of avascular necrosis in the chronic group; not a single case of acute cartilage necrosis was encountered. Owing to the rapid nature of growth plate closure following bone graft epiphysiodesis, the avoidance of hardware removal or pin penetration, and the extremely low incidence of overall complications, we suggest that bone graft epiphysiodesis is at least as good as multiple pin fixation in the treatment of slipped capital femoral epiphysis.

Fractures of the distal tibial epiphysis in adolescence.

We studied the cases of nine adolescent patients with a Salter-Harris Type-III fracture of the lateral portion of the distal tibial epiphysis (sometimes called the juvenile Tillaux fracture) and eight patients with a triplane fracture of the distal tibial epiphysis. The mechanism of both injuries was postulated to be external rotation of the foot on the leg. There were both two-fragment and three-fragment triplane fractures in the series. The three-fragment triplane fractures occurred in younger patients, and surgical treatment was more frequently administered. The pattern of closure of the distal tibial growth plate in the adolescent strongly influenced the type of fracture.

Correction by growth of rotational deformity after femoral fracture in children.

Fourteen children with femoral shaft fractures were studied for 10 years after fracture or until growth plate closure, using repeated anteversion measurements. A mean anteversion difference of 9.6 degrees between the fractured and intact sides after fracture consolidation decreased to 5.6 degrees (p less than 0.01), indicating that children have a considerable ability to correct a rotational deformity by growth, especially during the first years after fracture. It was also found that tibial pin traction results in a greater rotational deformity than does bilateral Bryant traction.