The prevalence of pseudoepiphyses in the metacarpals of the growing hand.

Normally the metacarpals have an epiphysis at one end--distally for the second to fifth and proximally for the first. Pseudoepiphyses are notches or clefts that occur at the non-epiphyseal ends of bones where an epiphyseal plate would be expected and are common incidental findings in the metacarpals of the growing hand. We aimed to identify the prevalence of pseudoepiphyses on serial radiographs of 610 healthy asymptomatic children. Pseudoepiphyses in the form of notches or clefts were common, identified most often in the second metacarpal (15.25%), fifth metacarpal (7.21%), and third metacarpal (0.49%). Complete pseudoepiphyses, in which the cleft extended across the full width of the metacarpal, were seen in the first metacarpal (1.97%) and the second metacarpal (1.31%). Pseudoepiphyses are a normal variant of metacarpal ossification and should not be confused with fractures in skeletally immature patients.

Functional adaptation through changes in regional biochemical characteristics during maturation of equine superficial digital flexor tendons.

OBJECTIVE: To quantify and compare biochemical characteristics of the extracellular matrix (ECM) of specimens harvested from tensional and compressive regions of the superficial digital flexor tendon (SDFT) of horses in age classes that include neonates to mature horses. SAMPLE POPULATION: Tendon specimens were collected on postmortem examination from 40 juvenile horses (0, 5, 12, and 36 months old) without macroscopically visible signs of tendonitis. PROCEDURE: Central core specimens of the SDFT were obtained with a 4-mm-diameter biopsy punch from 2 loaded sites, the central part of the mid-metacarpal region and the central part of the mid-sesamoid region. Biochemical characteristics of the collagenous ECM content (ie, collagen, hydroxylysylpyridinoline crosslink, and pentosidine crosslink concentrations and percentage of degraded collagen) and noncollagenous ECM content (percentage of water and glycosaminoglycans, DNA, and hyaluronic acid concentrations) were measured. RESULTS: The biochemical composition of equine SDFT was not homogeneous at birth with respect to DNA, glycosaminoglycans, and pentosidine concentrations. For most biochemical variables, the amounts present at birth were dissimilar to those found in mature horses. Fast and substantial changes in all components of the matrix occurred in the period of growth and development after birth. CONCLUSIONS AND CLINICAL RELEVANCE: Unlike cartilage, tendon tissue is not biochemically blank (ie, homogeneous) at birth. However, a process of functional adaptation occurs during maturation that changes the composition of equine SDFT from birth to maturity. Understanding of the maturation process of the juvenile equine SDFT may be useful in developing exercise programs that minimize tendon injuries later in life that result from overuse.

Bone lengthening for congenital differences of the hands and digits in children.

PURPOSE: We investigated the growth of bones after lengthening to evaluate the effectiveness and usefulness of bone lengthening in congenital hand deficiencies. METHODS: Bone lengthening was performed to treat congenital hand deficiencies including hypoplastic thumb, hypoplasia of the small finger, cleft hand, metacarpal synostosis, brachymetacarpia, symbrachydactyly, and amniotic band syndrome. A total of 15 patients (1-13 years old) underwent lengthening of 23 bones. The average of distraction was 10 mm. The mean follow-up period was 59 months. The length of the bones at follow-up evaluation was measured and then compared with the length of the bones immediately after lengthening. The bone growth after lengthening, the percentage of growth after lengthening, and the growth rate were compared among diagnostic groups. RESULTS: In the cases involving older patients the bone length changed little and the growth plates of these patients closed naturally soon after lengthening. In contrast, in the cases in which the patients were younger than 7 years old the lengthened bones grew continuously. The amount of bone growth was different for each disease in the younger patients. In patients with amniotic band syndrome the lengthened bones grew at the same rate as the bones in the hand. Other diagnoses such as symbrachydactyly had a different growth pattern in the hand. CONCLUSIONS: We conclude that bone lengthening is a reliable method for the correction of congenital differences of the hand. The indications for this procedure must be determined while considering the relationship between the specific disease and subsequent bone growth.

Mechanical correlations derived from segmental histologic study of the equine superficial digital flexor tendon, from foal to adult.

OBJECTIVE: To assess histologic variations of the equine superficial digital flexor tendon (SDFT) according to site and to horse age and activity, and to correlate these data with reported segmental mechanical results. SAMPLE POPULATION: Superficial digital flexor tendons isolated from 42 horses 0.5 hour to 23 years old. PROCEDURE: 7 segments of each SDFT were delimited and submitted for conventional histologic examination. Each segment was examined and graded for fiber undulation, cellularity, number and size of interfascicular connective spaces (ICS), presence or absence of focal and diffuse chondroid metaplasia, and differentiation of the dorsal (DB) and palmar (PB) borders of the tendon. RESULTS: Fiber undulation and cellularity significantly decreased with age. The proximal and middle metacarpal segment fibers were significantly less undulated and their ICS were smaller than those of the other segments, especially in old horses. Focal chondroid metaplasia developed from 5 years onward, mainly in the sesamoidean segments. Diffuse chondroid metaplasia was characteristic of the digital region in horses > 6 years old. The DB of the metacarpodigital region tended to differentiate into fibrocartilage in association with age. The PB was generally differentiated as nonfascicular dense connective tissue. Activity induced a decrease in the number and size of the ICS. CONCLUSIONS: The lesser undulation of the proximal and middle metacarpal segments fibers can be correlated to their mechanical behavior (stress-strain curve) and relative weakness within the SDFT. Focal chondroid metaplasia and fibrocartilage on the DB are normal features, related to the compression stresses undergone by the sesamoidean region of the tendon.

Desenvolvimento ósseo de crianças portadoras da síndrome de Down: estudo morfométrico radiográfico de ossos do carpo e metacarpo / The osseous development of Down's syndrome children: morphometric and radiographic study of the carpal and metacarpal bones

A criança é um ser em constante desenvolvimento, necessitando de análises criteriosas quanto ao seu padräo de crescimento e desenvolvimento, principalmente para a elaboraçäo de um adequado plano ortodôntico. No entanto, pouco se conhece a respeito do desenvolvimento de crianças portadoras da síndrome de Down. O presente estudo analisa o desenvolvimento ósseo de crianças portadoras desta síndrome, através de estudo morfométrico radiográfico de sete ossos do carpo e dos cinco ossos do metacarpo. As imagens radiográficas desses ossos foram transferidas, através de seus contornos, em folhas de papel vegetal, levadas a um scanner de mesa (HP SCANJET II CX), acoplado a um microcomputador Pentium 233 MHZ. Estas imagens foram captadas e morfometradas utilizando-se o software JANDEL SIGMASCAN IMAGE MEASUREMENT V 2.0, obtendo-se, assim, valores referentes às imagens das áreas dos ossos do carpo e comprimentos dos ossos do metacarpo. Estes valores obtidos nas análises morfométricas dos ossos das crianças com síndrome de Down, foram comparados com as imagens obtidas, desses mesmos ossos, de crianças normais, com as mesmas idades e ambos os sexos. Tabulados estes dados, foram eles submetidos à análise estatística através do teste de médias por comparaçöes múltiplas, ao nível de 5 por cento, com a utilizaçäo do sistema computacional SAS. Nas condiçöes experimentais deste trabalho e face a seus resultados, podemos concluir que as meninas portadoras da síndrome de Down, apresentaram desenvolvimento ósseo menor que o apresentado pelas meninas normais; as meninas portadoras da síndrome de Down, apresentaram desenvolvimento ósseo menor que os meninos portadores desta mesma síndrome e, os meninos portadores da síndrome de Down, apresentaram desenvolvimento ósseo semelhante aos dos meninos normais, em relaçäo aos picos de crescimento aos quatorze e quinze anos de idade

Investigation of bone developmental and histopathologic changes from intraosseous infusion.

STUDY OBJECTIVE: To evaluate clinical and cellular changes of bone through the rapid growth phase of development after intraosseous infusion of hypertonic or isotonic solutions at slow or fast infusion rates in a pig model. METHODS: This was a prospective, randomized, partially blinded, comparative study using a porcine model in an urban teaching hospital laboratory with further development in a local farm environment. Sixty pigs weighing 12 to 30 kg were anesthetized and endotracheally intubated, and a no. 15 Jamshidi bone marrow needle was inserted into a front forelimb. Hypertonic (mannitol) or isotonic (saline) solutions of 8 mL/kg were infused through the intraosseous site at a rapid or slow infusion rate. Animals were observed for approximately 6 months, after which they were killed and the front forelimbs harvested for gross pathologic and histologic evaluation. RESULTS: No clinical complications were noted in any of the animal groups. No substantial histologic differences were found between the hypertonic and isotonic groups. Although gross pathologic lesions were found in 32% of the hypertonic groups and in fewer than 5% of the isotonic groups, this difference was not statistically significant. Equal bone changes were found in the slow- and rapid-infusion groups. CONCLUSION: The rate of intraosseous infusion and the osmolarity of the infused fluid did not appear to be related to any gross pathologic or histologic cellular or marrow changes or to any clinical complications in animal development in this study.

Metacarpophalangeal pattern profiles: Q-score for ages from birth to 7 years.

The metacarpophalangeal pattern profile (MCPP) analysis is a widely used method of standardization of bone length measurements to quantify congenital skeletal dysplasia of the hands. A main source of inaccuracy is the prominent scatter in the values of the standard deviation (S.D.) of the reference length, which is used in the calculation of the standardized values (Z-scores). Other sources of error, especially when bone length measurements of younger children are evaluated, are the rather large variability in the age of appearance of the epiphyses of the different bones, and the use of tabulated reference data which are available only at one-year intervals. We have devised another method of standardization of bone length measurements, by calculating the Q-score. Its advantages are that no S.D. values are needed and that more accurate results are obtained. Moreover the interpretation of the Q-scores is more straightforward than the interpretation of the Z-scores. Q-scores for 3 patients with Sotos syndrome are presented. Use of the MCPP in the form of the Q-score, will probably make it an even stronger tool than before.

Growth-promoting effect of human growth hormone on patients with achondroplasia.

To evaluate the effect of human growth hormone (hGH) on the growth of children with achondroplasia, three patients with achondroplasia and one patient with hypochondroplasia were treated with 0.5 IU/kg/W of pituitary-extracted hGH for 6-12 months. Mean height velocity was significantly increased from 4.0 +/- 0.4 to 7.5 +/- 0.7 cm/year (P less than 0.05) by hGH. The tibial index, defined as the length/width ratio of left tibia, did not change during the treatment, indicating that hGH promotes growth without exaggeration of tubular bone deformity. Case 2, who had atlantoaxial dislocation, developed sleep apnea and neurological deficits during the second hGH treatment, but these were cured by operation. Thus, hGH therapy is effective in promoting growth in patients with achondroplasia, but the complication of atlantoaxial dislocation should be explored and corrected before the treatment.

Análise morfométrica do crescimento dos ossos metacarpais no período fetal: aplicaçöes à imageria médica / Morphometrical analysis about the growth of the metacarpal bones during fetal period: applicability to medical imaging

O crescimento dos ossos metacarpais da mäo direita de 50 fetos humanos foi estudado com base em 3 mensuraçöes: comprimento total (CT), comprimento da diáfise ossificada (CO), e a largura da parte média do ossso (LM). A equaçäo Y=aXb (método alométrico) foi usada para ajustar os dados, sendo que x correspondeu à idade gestacional e Y às medidas metacarpais. Estas crescem com coeficiente alométrico b positivo. O crescimento de CO mostrou os maiores valores de b, e a velocidade de crescimento de LM foi mais intensa que a de CT. As equaçöes de crescimento dos ossos metacarpais e seus respectivos gráficos säo parâmetros quantitativos importantes, atualmente, para o diagnóstico pré-natal de deformidades congênitas da mäo, pela primeira vez determinados na populaçäo brasileira

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.

The effect of whole-body irradiation on skeletal growth in rhesus monkeys.

Late effects of single whole-body doses of 400--500 and 750--900 rads on skeletal growth in 32 rhesus monkeys were studied. Findings indicated growth inhibition strongly related to dose and age at irradiation. Doses of 750--900 rads before the age of 40 months resulted in significantly greater growth inhibition (11%) than doses given during or shortly after adolescence (p less than 0.005). Doses of less than 750 rads were not significant. In view of the close similarity between monkeys and man, irradiation of children at doses greater than 750 rads may carry a strong risk of subsequent growth retardation.