Additional manal and pedal epiphyseal centres

One hundred and thirty-six well-preserved medieval skeletons were excavated in advance of re-development in Norwich. Examination of sub-adult hand and feet bones indicated a high percentage of accessory epiphyses. The majority could be identified by traces of a fusion line. The distal first metacarpal and first metatarsal being the preferred sites. Such additional epiphyses have rarely been reported in archaeological samples and the findings are in strong contrast to the figures quoted in modern anatomical texts. The possible reasons for this apparent variation are discussed.

Bone tissue composition, dimensions and strength in female rats given an increased dietary level of vitamin A or exposed to 3,3',4, 4',5-pentachlorobiphenyl (PCB126) alone or in combination with vitamin C

In previous studies we have described structural and functional changes in rat bone tissue caused by 3,3',4,4',5-pentachlorobiphenyl (PCB126). Some of the effects caused by PCB126 resemble those found in vitamin C-deficient rats, as well as those found in rats with a high dietary intake of vitamin A. The present investigation was designed to determine if these PCB126-induced changes could be inhibited by addition of vitamin C to the drinking water and if they could be evoked by vitamin A administration. Five groups of female rats were used in this study, which lasted for 12 weeks. Three of the groups were exposed to PCB126 (total dose 320 microgram/kg, bw), either alone or in combination with vitamin C added to the drinking water (1 and 10 g/l, respectively). One group was given feed with increased level of vitamin A (600000 U/kg pellet) and the fifth group served as controls. Using peripheral quantitative computed tomography (pQCT), it was found that PCB126 increased trabecular density and cortical thickness, but reduced the trabecular area. Furthermore, maximum torque and stiffness of the humerus during torsional testing and serum osteocalcin levels were reduced by PCB126. Of the PCB126 induced effects observed, addition of vitamin C only inhibited the reduction of serum osteocalcin. Like PCB126 vitamin A supplementation increased the inorganic content and the bone density and also reduced the trabecular area and polar moment of inertia but did not increase the cortical thickness or reduce maximum torque, stiffness or serum osteocalcin level. Apparently, the effects induced by PCB126 are not mediated either via decreased vitamin C level or increased vitamin A level.

Spatial arrangement of physeal cartilage chondrocytes and the structure of the primary spongiosa

Using laser confocal microscopy and 5-chloromethyl-fluoresceindiacetate (CMFDA) loading of chondrocytes we have investigated the structure of the ovine physis during late fetal development and its relationship to the structure observed in the primary spongiosa. Chondrocytes within the ovine growth plate form nests that together span the growth plate. We propose that all growth plates may be composed of nests of cells, but that the length of the individual nests changes between growth plates and with gestational age. The continuous column of cells seen within some growth plates is a nest of cells that is in the process of being absorbed by the invading metaphyseal front. Scanning electron microscopy of the mineralized portion of the primary spongiosa revealed structures that were consistent with the hypothesis that the cartilage surrounding the nest structure gives rise to the structure in the primary spongiosa. Although mineralization does not occur between cells within a nest, bands of mineral form between nests in the lower hypertrophic region and around the end of the nest as it reaches the hypertrophic region. This pattern of mineralization around and between nest termini yields the complex three-dimensional network of mineralized trabeculae observed in the primary spongosia.

[The morphometric and strength characteristics of the femur for the biomechanical validation of blocking intramedullary osteosynthesis]

A technique is submitted together with a device for measuring the thigh-bone proximal and distal metaepiphyses substantia spongiosa macrohardness to assess stability of the diaphyseal fractures intramedullary osteosynthesis. Data are secured on sizes of the medullary cavity cross-section, thickness of the compact bone tissue, indices for macrohardness of the femoral metaepiphyses substantia spongiosa in frontal and sagittal planes. The results obtained will, we believe, help in finding an optimum construction and technique for osteosynthesis.

Normal maturation of the distal femoral epiphyseal cartilage: age-related changes at MR imaging

PURPOSE

To determine how signal intensity in the cartilaginous distal part of the femoral epiphysis varies with (a) age, (b) sex, and (c) distribution to the medial or lateral condyle on magnetic resonance (MR) images.

MATERIALS AND METHODS

Sixty-six sagittal T2-weighted or inversion-recovery MR images of the distal femoral epiphysis in children aged 2 months to 5 years 5 months were evaluated. Epiphyses were categorized into five types on the basis of progressive signal intensity changes within the epiphyseal cartilage along the weight-bearing region and posterior condyles. Epiphyseal type was compared with age, sex, and distribution of signal intensity changes within the condyle.

RESULTS

In early infancy, epiphyseal cartilage was homogeneous. During the 2nd year, signal intensity along the weight-bearing region decreased. With further advancing age, signal intensity in the posterior femoral condyles increased and became progressively more focal. The increase in epiphyseal grade correlated with age for both the medial and the lateral femoral condyles (r = 0.71 and r = 0.77, respectively; P < .001). There was no significant difference in epiphyseal changes between boys and girls or between medial and lateral condyles.

CONCLUSION

There is normal age-related variation in MR imaging signal intensity within the cartilaginous epiphysis of the distal femur. This may be related to weight bearing and epiphyseal maturation and should not be confused with disease.

Sex determination by discriminant function analysis of the right tibia in the prehispanic population of the Canary Islands

This study has been performed in order to define standards usable to determine the sex of prehispanic individuals from the Canary Islands from their skeletal remains. Osteometric information at the right tibia was obtained from 59 complete skeletons from Gran Canaria, housed in the Museo Canario (Las Palmas), 45 males and 14 females (this constitutes the totality of complete prehispanic skeletons known from Gran Canaria). The parameters measured were: tibial length, proximal and distal epiphyseal breadth, transverse and anteroposterior diameter, perimeter at the nutrition foramen levels and minimum shaft perimeter. These parameters were subjected to different SPSS discriminant function analysis, combining all of them, or only the proximal or distal ones, without tibial length, etc., in order to obtain functions usable even if only bone fragments are available. Transverse diameter, proximal epiphyseal breadth and minimum shaft perimeter showed the highest discriminant power. The functions obtained showed high average accuracies, ranging from 94.9 to 98.3%, with female accuracies of 100%. The functions obtained were further applied to a test prehispanic population (ten males and ten females) from El Hierro. Overall accuracies of the functions when applied to this population ranged from 65 to 94.7%, with female accuracies ranging 80% to 100%.

Spatiotemporal change of rat collagenase (MMP-13) mRNA expression in the development of the rat femoral neck

The interepiphyseal region between the greater trochanter and the capital femoral epiphysis and the medioproximal portion of the femoral neck exhibit extensive morphological changes during the first 4 weeks after birth in rats. Previous reports show that matrix metalloproteinase-13 (MMP-13, rat collagenase) mRNA is expressed in bone and cartilage during embryonal development and fracture healing. We examined MMP-13 mRNA expression and compared it with the distribution of osteopontin and osteocalcine mRNA in the femoral neck. Moreover, we examined histomorphometric analysis in the femoral neck where the morphology changes rapidly. Histomorphometric analysis of the 4-week-old rat femoral neck showed a high rate of bone formation and resorption in the region where shape changed rapidly. Osteopontin mRNA was expressed diffusely along the endosteum. In contrast, MMP-13 mRNA expression was restricted to the medial endosteal portion near the cartilage-bone interface of the femoral neck in 15- and 28-day-old rats and in the deepest endosteal interepiphyseal region of 15-day-old rats. MMP-13 mRNA-expressing osteoblastic cells were also expressing osteopontin but not osteocalcin mRNA. MMP-13 mRNA-expressing cells differ from tartrate-resistant acid phosphatase (TRAP)-positive cells, and MMP-13 mRNA-positive cells are located adjacent to TRAP-positive cells. The results of the site- and cell-specific expression of MMP-13, taken together with its enzymatic property, suggest that MMP-13 plays an important role in morphological changes in the rat femur, at least during the third and fourth week after birth, and that MMP-13 itself is involved in the interaction between osteoblastic and TRAP-positive cells.

Deletion of Ku86 causes early onset of senescence in mice

DNA double-strand breaks formed during the assembly of antigen receptors or after exposure to ionizing radiation are repaired by proteins important for nonhomologous end joining that include Ku86, Ku70, DNA-PK(CS), Xrcc4, and DNA ligase IV. Here we show that ku86-mutant mice, compared with control littermates, prematurely exhibited age-specific changes characteristic of senescence that include osteopenia, atrophic skin, hepatocellular degeneration, hepatocellular inclusions, hepatic hyperplastic foci, and age-specific mortality. Cancer and likely sepsis (indicated by reactive immune responses) partly contributed to age-specific mortality for both cohorts, and both conditions occurred earlier in ku86(-/-) mice. These data indicate that Ku86-dependent chromosomal metabolism is important for determining the onset of age-specific changes characteristic of senescence in mice.

Growth cartilage: normal appearance, variants and abnormalities

The cartilaginous structures in the growing ends of the bone have a complex anatomy. MR imaging allows exquisite depiction of these structures. The normal anatomy and biochemical features of the zones of cartilage are reviewed. Based on an analysis of signal characteristics, it is possible to optimize the use of pulse sequences to study the normal structures and abnormalities of growing bone.

A rare case of complete proximal epiphyses (so-called pseudoepiphyses) of the metacarpal and metatarsal bones in the human

We report a rare case of complete proximal epiphyses (so-called pseudoepiphyses) of metacarpal and metatarsal bones in a human. These phenomena were seen in both the hands and feet of a seven-year-old girl undergoing medical examination for pain in the right foot. During medical treatment, X-ray photographs of the hands and feet were taken. Each metacarpal and metatarsal bone except for the first metacarpal bones had supernumerary epiphyses (complete pseudoepiphyses) at the nonepiphyseal end of these bones. This is a rare case even for an experienced orthopaedic surgeon.

Developmental variation in lumbosacropelvic anatomy of thoroughbred racehorses

OBJECTIVE

To describe the incidence and types of gross osseous developmental variations and ages of physeal closure in the caudal portion of the thoracic and lumbosacral spine and the pelvis in a sample of Thoroughbred racehorses.

ANIMALS

Thoroughbred racehorses (n = 36) that died or were euthanatized at California racetracks between October 1993 and July 1994.

PROCEDURE

Lumbosacropelvic specimens were collected, and all soft tissues were removed. The osseous specimens were visually examined.

RESULTS

Only 22 (61%) specimens had the expected number of 6 lumbar and 5 sacral vertebrae. Eight (22%) specimens had thoracolumbar transitional vertebrae, and 13 (36%) had sacrocaudal transitional vertebrae. Articular process asymmetries were present at 1 or more vertebral segments in 30 (83%) specimens. Intertransverse joints (2 to 4 pairs/specimen) were bilaterally distributed in the caudal portion of the lumbar spine and the lumbosacral joint in 31 (86%) specimens. Five (14%) specimens had asymmetric distribution of the intertransverse joints. Intertransverse joint ankylosis was found in 10 (28%) specimens. Lumbosacral vertebral body physeal closure occurred between 4.9 and 6.7 years of age; pelvic physeal closure occurred between 5.2 and 5.8 years of age. Iliac crest and ischial arch epiphyseal formation was evaluated, using a grading system, and fusion to the underlying bone occurred at 7.2 years and 5.4 years of age, respectively.

CONCLUSIONS

Numerous vertebral anatomic variations were commonly found in a sample of Thoroughbred racehorses.

CLINICAL RELEVANCE

Normal anatomic variations and ages of skeletal maturity need to be considered in clinical evaluation of the equine spine and pelvis for differentiation from pathologic findings.

Normal gadolinium-enhanced MR images of the developing appendicular skeleton: Part 2. Epiphyseal and metaphyseal marrow

OBJECTIVE

We have studied how gadolinium enhancement of T1-weighted MR images affects the expected normal differences in signal intensity between metaphyseal hematopoietic and epiphyseal fatty marrow. We have also analyzed how enhancement affects the expected normal changes in the MR images of the marrow due to fatty conversion.

MATERIALS AND METHODS

We analyzed gadolinium-enhanced MR images of normal distal femurs in 18 immature rabbits that were 5-11 weeks old and of normal proximal femurs in 18 infants, children, and young adults who were 2 months to 21 years old. In all subjects, we studied the change with age in signal intensity and enhancement ratio of the epiphyseal and metaphyseal marrow. In the rabbits, marrow composition and transformation were histologically verified.

RESULTS

On unenhanced T1-weighted MR images of the rabbits and of the infants, children, and young adults, epiphyseal signal intensity always exceeded metaphyseal signal intensity; however, the enhancement ratio was always greater in the metaphysis. The signal intensity in metaphyseal and epiphyseal marrow on unenhanced MR images increased with age. However, enhancement ratios decreased with age in both areas. In the rabbits, histologic studies showed more fatty marrow in the epiphysis than in the corresponding metaphysis and an age-related increase in marrow fat at both sites.

CONCLUSION

In the marrow of the extremities, gadolinium enhancement is greater in the (hematopoietic) metaphysis than in the (fatty) epiphysis. In both areas, enhancement decreases as the marrow becomes more fatty. On T1-weighted images, administration of a gadolinium-containing contrast agent reduces the normal contrast between hematopoietic and fatty marrow and obscures the changes in marrow signal intensity due to fatty conversion.

Normal gadolinium-enhanced MR images of the developing appendicular skeleton: Part I. Cartilaginous epiphysis and physis

OBJECTIVE

We have used gadolinium-enhanced MR imaging to define the expected normal appearance of the developing cartilaginous epiphyses and physes in neonates, infants, and children and to define the changes with maturity in epiphyseal vascular pattern.

MATERIALS AND METHODS

We analyzed gadolinium-enhanced MR images of 80 normal epiphyses in 48 neonates, infants, and children who were 1 month to 15.5 years old. We studied the differences in enhancement ratios for the epiphyses and physes and the epiphyseal vascular pattern at various development stages. We correlated the MR imaging findings with histologic and injection studies of immature epiphyses.

RESULTS

Gadolinium enhancement allowed differentiation between physeal and epiphyseal cartilage and revealed epiphyseal vascular canals. Enhancement proved to be greater in the physeal than in the epiphyseal cartilage (p < .001). In the unossified epiphysis, the vascular canals were mainly parallel. After the development of the secondary ossification center, these canals came to have a radial pattern (p < .0001). Comparison with cadaveric specimens confirmed how, with age, the arrangement of these canals changed. Also, physeal enhancement decreased with physeal closure.

CONCLUSION

Gadolinium-enhanced MR imaging reveals differential enhancement of the physis, epiphyseal vascular canals, and epiphyseal cartilage. The pattern of epiphyseal vessels and degree of enhancement of the physis change with maturity.

[A unicompartment knee prosthesis: the effect of the positioning of the tibial plate on the functional results]

The authors analyse the results of 51 unicompartmental knee prostheses with 1 to 12 years follow-up (mean follow-up: 5 years). The results were evaluated using the scoring system of the "Knee Group" of the SO.B.C.O.T. (Société Belge de Chirurgie Orthopédique et de Traumatologie). This analysis demonstrates that the quality of the results depends on implant positioning. The authors suggest positioning the tibial implant parallel with the healthy plateau and slightly distal, i.e. to position the tibial implant perpendicular to the epiphyseal axis and not to the mechanical axis, as is systematically done with the usual tibial cutting guides. When this ideal positioning was respected, 77.5% of the patients had a score above 90 points (out of a possible maximum of 100 points) and 12.5% had a score between 75 and 89 points. When this condition was not respected, none of the knees obtained more than 75 points. The difference was statistically significant (p = 0.0001).

Physeal form of the longbones of the foal

The possible relationship between physeal diseases and physeal form prompted investigation of change in steepness of the physis in young foals. The distal and proximal aspects of the longbones were sawn sagittally in the right and frontally in the left bones. The slabs were washed to remove saw debris, arranged in order and inspected. The proximal physes had a flat or gently arched form, without obvious inclination. In the distal physes there were distinct inclinations. Inspection of an identical slab from the medial aspect of the distal radius of two series of foals of different breeds showed that the degree of inclination of the physis with respect to the long axis of the bone increased with age. In a further series of foals, the angle of inclination was measured from radiographs of identical sagittal and frontal slabs of the distal radius. A line drawn through the secondary spongiosa was produced to intersect a line drawn along the physis where it was mostly steeply inclined, and the angle measured. The angle decreased (physeal inclination increased) with increasing age, up to 35-90 days. The steepness in the lateral aspect of the physis was similar to that in the medial aspect, although evident in a different plane.

[Age-dependent MR imaging of the tibia in children up to 2 years old. The findings in children without bone marrow-relevant diseases or therapies]

PURPOSE

Since the beginning of bone marrow conversion presents with substantial differences as shown by anatomical or magnetic resonance studies, the purpose of this study was to demonstrate via MRI an age-dependent bone marrow conversion of the tibia in children of up to two years of age.

METHODS

We studied the bone marrows of the tibia in 24 children ranging from one month to two years by means of MRI. T1-weighted SE-sequences were used. Children who suffered from diseases affecting the bone marrow were excluded. A retrospective analysis of the MR images was performed.

RESULT

A gradual increase of signal intensity could be demonstrated in the epiphyses and the diaphysis of the tibia beginning shortly after birth. During the first two years of life a further increase of signal intensity could be observed in these regions, progressing through metaphyses up to the growth plates.

CONCLUSION

First signs of bone marrow conversion can be detected in the tibia shortly after birth. Bone marrow infiltration in the tibia is expected to be recognised by MRI from this time onward.

Radiographical evaluation of bone maturation in Japanese black beef cattle

Epiphyseal ossification in the radius, ulna, metacarpus, proximal phalanx and tuber calcaneus was examined radiographically in Japanese Black beef cattle. The grade of standard ossification was assessed monthly for each epiphysis. Bone maturations could be divided into 8 grades for the distal radius and distal ulna, 7 grades for the distal metacarpus, 5 grades for the proximal phalanx, and 8 grades for the tuber calcaneus, respectively. The closure of the epiphyseal line completed at the earliest (12-14 months of age) on the proximal phalanx, and at the latest (35-37 months of age) on the distal ulna. Changes in gradings were steep at 0 to 5 months of age but became almost constant after 10 months of age in all the epiphyses. There were no significant differences in bone maturation between the cattle with different sex and breeding conditions.

Characteristics of blood vessels feeding the femoral head liable to osteonecrosis in spontaneously hypertensive rats

In order to elucidate the cause of osteonecrosis of the femoral head in spontaneously hypertensive rats (SHRs), which resembles the osteonecrosis of Perthes' disease, we observed the three-dimensional structure of vascular casts of the blood vessels feeding the femoral head using both optical and scanning electron microscopes. During the period of 9-15 weeks after birth, when osteonecrosis of the femoral heads in SHRs occurred frequently, the lateral epiphyseal vessels (LEVs), which were the main feeding vessels, entered from the lateral of the femoral heads. Anastomosing branches of LEVs between the epiphysis and the femoral neck were scarce even in the femoral heads showing normal ossification. It seemed that the development of LEVs in SHRs did not proceed normally in this period. Furthermore, remarkable segmental stenosis and the obstruction of LEVs were often recognized near the lateral of the femoral heads. These results suggest that LEVs in growing SHRs have the vascular structure that could cause an interruption of the blood supply to the femoral heads.

Musculo-articular modelling of the triceps brachii

With the aim of proposing modelling equations for the length, force and shortening velocity of the triceps brachii, an X-ray and biomechanical study was carried out on the elbow joint. Two series of three upper right limbs removed from cadavers were used. It allowed us to situate the articular rotational axis of the elbow and to modelise the lever arm of the muscle group of the elbow extensors. Eight superimposed X-ray films with opaque markers at different articular angles show that the rotational axis of the elbow is different from the epitroch-lea-epicondyle axis, commonly localised by palpation and used as such in functional and biomechanical explorations. This rotational axis of the elbow, situated in the trochlea, is fixed at the centre of the articular range and moves noticeably to both extremities of this range. Biomechanical study, based on measurement of internal and external torques established using an overload, allowed us to modelize the lever arm of the triceps brachii between 0 and 2.44 radians, according to length of the ulna. The applications concerning length, force and shortening velocity of the triceps brachii are described. This method of modelling is applicable to other joints and muscle groups.

Ulnar collateral ligament in the growing elbow: MR imaging of normal development and throwing injuries

PURPOSE

To study the magnetic resonance (MR) imaging appearance of the ulnar collateral ligament (UCL) and its insertion into the medial epicondyle.

MATERIALS AND METHODS

Sixteen normal and 20 symptomatic elbows were examined with a 1.5-T unit. Normal elbows were imaged with axial T2*-weighted three-dimensional Fourier transform sequences. Symptomatic elbows were imaged with coronal T1-, T2-, and T2*-weighted and/or short-inversion-time inversion-recovery sequences.

RESULTS

In normal immature elbows, the ulnar periosteum was seen as an extension of the UCL, and its enthesis had signal intensity characteristics that differed from those of the mature ligament. In symptomatic elbows imaged before epiphyseal fusion, segmentation and subchondral bone resorption of the ossification center were seen with or without a capsular tear. After epiphyseal fusion, a full-thickness or a partial UCL tear at the site of its insertion, with or without subcortical bone resorption, was seen.

CONCLUSION

The MR imaging characteristics of the developing elbow differ from those of the mature elbow. MR imaging is useful in assessing UCL damage.

Ossification and pseudoepiphysis formation in the "nonepiphyseal" end of bones of the hands and feet

Metacarpals, metatarsals, and phalanges were studied to assess the developmental morphology of "secondary" ossification in the "nonepiphyseal" ends of these bones as well as the formation of the pseudoepiphysis as an epiphyseal ossification variant. Both direct ossification extension from the metaphysis into the epiphysis and pseudoepiphysis formation preceded, and continued to be more mature than, formation and expansion of the "classic" epiphyseal (secondary) ossification center at the opposite end of each specific bone. Direct metaphyseal to epiphyseal ossification usually started centrally and expanded hemispherically, replacing both physeal and epiphyseal cartilage simultaneously. In contrast, when remnants of "physis" were retained, while juxtaposed epiphyseal cartilage was replaced, a pseudoepiphysis formed. There were three basic patterns of pseudoepiphysis formation. First, a central osseous bridge extended from the metaphysis across the "physis" into the epiphysis and subsequently expanded to create a mushroom-like osseous structure. In the second pattern a peripheral osseous bridge formed, creating either an osseous ring or an eccentric bridge between the metaphysis and the epiphysis. In the third pattern, multiple bridging occurred. In each situation the associated remnant "physis" lacked typical cell columns and was incapable of significantly contributing to the postnatal longitudinal growth of the involved bone. Pseudoepiphyses were well formed by 4-5 years and coalesced with the rest of the bone months of years before skeletal maturation was attained at the opposite epiphyseal end, which ossified in the typical pattern (i.e., formation of a secondary center de novo completely within the cartilaginous epiphysis). This process may also affect the development and appearance of ossification within the longitudinal epiphyseal bracket ("delta phalanx").

Hematopoietic bone marrow within the proximal humeral epiphysis in normal adults: investigation with MR imaging

The occurrence of hematopoietic bone marrow within the axial skeleton and meta-diaphyseal regions of long bones is well known. However, it has been generally accepted that hematopoietic marrow is not present within the epiphysis of long bones in normal adults. This study involved evaluation of marrow patterns in 96 patients presenting for shoulder magnetic resonance (MR) imaging examinations. Residual hematopoietic marrow was present within the proximal humeral metaphysis in 99% of patients and extended into the epiphysis in 62%. Epiphyseal hematopoietic marrow was more prominent in female subjects (P = .015) and showed correlation with prominence of hematopoietic marrow within the proximal humeral metaphysis (P = .01). The most characteristic pattern was a curvilinear distribution of hematopoietic marrow involving the subcortical region of the medial humeral head, though in some patients more centrally located patchy or globular regions of hematopoietic marrow were observed. These findings indicate that when signal intensity variations are observed within the epiphysis on MR images, the possibility of residual or reconverted hematopoietic marrow should be considered.

Intraosseous infusion of resuscitative fluids and drugs: long-term effect on linear bone growth in pigs

We studied the effects of intraosseous (IO) infusion of a standard fluid bolus and resuscitative drugs on long-term bone growth and epiphyseal closure in the "pediatric" swine model. Eighteen weanling pigs were randomly assigned to six groups as follows: three animals received two normal saline boluses, 20 mL/kg IO over 20 minutes; three received sodium bicarbonate, 1 mEq/kg IO; three received a 10% sodium bicarbonate infusion IO at maintenance rate over 1 hour; three received epinephrine 1:10,000, 0.1 mL/kg IO; three received an epinephrine infusion IO at 1 microgram/kg/min for 1 hour; and three received a dopamine infusion IO at 10 micrograms/kg/min for 1 hour. All infusions were given in the left hindleg; the right hindleg was used as a control. Lateral radiographs of the hind extremities were obtained at the beginning of the study and at 1 and 3 months after infusion. Linear radiographic measurements of the infused and control tibias were compared. At 6 months after infusion, the tibias were harvested, measured directly, and radiographed to determine the degree of epiphyseal closure. Analysis of variance for the first 3 months' data yielded a nonsignificant time-by-treatment interaction (P = .84) and a nonsignificant main effect for time (P = .22). Separate analysis of the direct measurements taken at 6 months revealed no difference in growth between experimental and control tibias. In addition, no radiographic difference in epiphyseal closure was noted between the two groups at the conclusion of the study, nor were any structural defects discovered. Intraosseous infusion of fluids and resuscitative drugs does not adversely affect subsequent bone growth and development in the swine model.

Cartilaginous epiphysis and growth plate: normal and abnormal MR imaging findings

The cartilaginous structures at the ends of growing bones constitute the "growth mechanism." These structures are not visible on radiographs, but they can be seen with MR imaging. Improved definition of cartilaginous abnormalities by MR imaging may permit earlier detection and treatment of these disorders and thus prevent bone deformity. This pictorial essay contains examples of normal and abnormal growth cartilage as seen with MR imaging. The indications for MR imaging in the evaluation of certain growth disorders are discussed, and the usefulness of MR imaging in certain clinical situations in which the role of this technique is still evolving is illustrated.

Morphology of epiphyseal apparatus of a ranid frog (Rana Esculenta)

Morphological, histochemical and ultrastructural investigations on epiphyseal apparatus of Rana Esculenta were made. The most important findings were the following: 1) metaphyseal cartilage is localized inside proximal diaphyseal compact bone as a plug; 2) metaphyseal cartilage do not reduce in thickness during ageing; 3) metaphyseal cartilage do not show vascular invasion and do not mineralize in degenerative zone; 4) trabecular bone was not at all evident in this animal; 5) external periosteum is well vascularized and proliferates in correspondence to marginal epiphyseal end of the diaphyseal. From these results the hypothesis that the ranid frog bone growth is not due to metaphyseal metabolism (as in avian and mammals) but to bone periosteal marginal mineralization is reached.

Growth of the perichondrium and the chondroepiphysis: experimental approach in the rat proximal tibial epiphysis

In the present paper we study the participation of the perichondrium in chondroepiphysis development analyzing its in vitro growth pattern without the perichondrium. We also advance the descriptive morphological results. We have observed that the chondroepiphysis without perichondrium grew with an almost normal pattern. Most of the cells that participated in chondroepiphysis growth came from the lateral region of the growth plate.

Epiphyseal marrow in infancy: MR imaging

Hypointense epiphyseal marrow on T1-weighted magnetic resonance images often suggests disease. To determine whether hypointense marrow sometimes represents normal red marrow in a recently ossified epiphyseal center, the authors studied 38 infants without known marrow disease. Patients with hypointense epiphyseal marrow on T1-weighted images were younger (3.9 months +/- 3.2) than those with hyperintense marrow (9.6 months +/- 3.9) (P less than .001). T1-weighted imaging and histologic correlation were also performed in animals. The signal was hypointense and the marrow was red in the epiphyseal centers of all newborn animals, while all 6-week-old animals had hyperintense signal and yellow marrow. The authors conclude that hypointense marrow on T1-weighted images represents normal red marrow in a recently formed ossification center in newborn rabbits and lambs, and the same is probably true in humans. Epiphyseal marrow becomes hyperintense within a few months of development of the secondary center of ossification.

In vivo quantitative characterization of trabecular bone by NMR interferometry and localized proton spectroscopy

In trabecular bone the NMR linewidth is found to be governed by the magnetic field inhomogeneity arising from the difference in magnetic permeability between bone and marrow. T2* was measured in vivo in the distal femur by interferometry and localized spectroscopy. Both methods showed T2* to be inversely related to trabecular plate density.

Postnatal epiphyseal development: the distal tibia and fibula

At birth, the distal tibial physis is a transverse structure. However, as the tibia enlarges diametrically and the epiphyseal ossification center matures, the physis becomes increasingly undulated, with peripheral lappet formation. The anteromedial area is the first to develop undulation (Poland's hump). This should not be misinterpreted as an injury or premature epiphyseodesis subsequent to trauma. The tibial secondary ossification center forms within the central epiphysis. The medial margin is irregular and may have peripheral foci of ossification. Between the ages of 7 and 8 years, this secondary center extends into the medial malleolus, reaching the distal tip during adolescence. The malleolar tip may develop accessory ossification. Physiologic epiphyseodesis begins over the medial malleolus and then extends laterally, a pattern of closure that affects fracture patterns (e.g., the fracture of Tillaux). The distal fibular physis also begins as a transverse structure that becomes undulated and has extensive peripheral lappet formation. This physis usually becomes level with the articular surface of the distal tibia after the first year. Enchondromalike extensions of the physis into the metaphysis are common. Accessory ossification may develop at the distal end.

Transphyseal linear ossific striations of the distal radius and ulna

Radiologic and histologic analysis of transphyseal linear ossific striations of the distal ulna and radius showed that these striations consist of trabecular bone extending from the metaphysis across all zones of the physis into a small focus of fibrous and necrotic tissue within the epiphyseal cartilage. The focus appears to be a discrete area of epiphyseal ischemia with subsequent necrosis within and around the vasculature of a cartilage canal and probably represents a microscopic response to antecedent trauma that was insufficient to cause macrofailure (fracture) of the physis. The striations did not continue into the epiphyseal ossification center. The consequence is partial osseous bridging across the physis. This bridging is unlikely to cause significant growth damage, since in most cases it does not appear to extend farther into the secondary ossification center.

Three-axial strain controlled testing applied to bone specimens from the proximal tibial epiphysis

Reproducibility of the determination of Young's modulus and energy absorption along the three axes of trabecular bone cubes was analysed by non-destructive compression to 0.5% strain using different testing protocols. These protocols included testing with and without pre-conditioning to a viscoelastic steady state, and different orders of test directions. Reproducibility of conditioned tests was generally better than that of non-conditioned tests. No major effect of changing the order of the test direction was found. Three-axial conditioned testing of cubes from the proximal tibial epiphysis of five humans revealed a global transverse isotrophy while most cubes showed orthotropy. The ratio between stiffness along the long axis of the tibia and the stiffness in the transverse plane was 3.7 +/- 0.4 (mean +/- 2 SE). The corresponding ratios for elastic energy storage and viscoelastic energy dissipation were 2.5 +/- 0.2. There was no difference between the relative energy loss during a testing cycle (loss tangent) in the three axes.

Estimating gestational age in the term pregnancy with a model based on multiple indices of fetal maturity

A prospective ultrasonographic study was conducted in 100 normal pregnant women with gestational ages that ranged from 36 to 42 weeks in which multiple biometric measurements were obtained. Dimensions of the distal femoral, proximal tibial, and proximal humeral epiphyseal ossification centers, as well as the placental and colonic grades, were also evaluated. A high statistical correlation was found between gestational age and each of the five variables (p less than 0.001). With a stepwise linear logistic regression analysis, we determined that gestational ages (36 to 39 weeks and 40 to 42 weeks) could be ascertained with a high probability with the use of a combination of the proximal humeral epiphysis and colonic grades. Probability estimates were not significantly affected by the addition of the distal femoral, proximal tibial epiphyses, placental grade, or amniotic fluid volume. From these data, probability prediction tables were generated. The results of this study provide an alternate method by which gestational age may be estimated in late pregnancy.

Bone age at birth; method and effect of hypothyroidism

Bone maturity at birth (or during the neonatal period) can be estimated from the ossified distal femoral epiphyses (FE). In congenital hypothyroidism (CHT) bone maturation is retarded and neonatal bone age reflects the severity of prenatal thyroid failure. In our reference group of 111 healthy infants, the size of these epiphyses depended not only on the age but also on body size. Thus, if bone age is estimated from the size of an epiphysis, the size of the infant is a potential confounder. This problem was avoided by estimating the maturation lag from the difference between the observed and predicted heights of FE (FEHs). Models for predicting FEH were constructed from data from the reference group by multiple linear regression and confirmed in a separate group of 37 healthy infants. In 52 hypothyroid newborns both FEH and FEH lag correlated with serum thyroxine concentration, indicating that FEH can be used as a measure of bone maturation in a population that is fairly homogeneous for (postmenstrual) age and size. Otherwise FEH lag is a better indicator.

The vascular supply of the chondro-epiphyses of the elbow joint in young swine

The vasculature of the elbow joint was examined in 39 pigs between one day and 15 weeks of age. Each pig was anaesthetised, exsanguinated and the thoracic limbs were perfused with India ink or a silicone rubber injection compound. The humerus, ulna and radius were dissected free, examined, fixed in formalin or ethyl alcohol, cleared by the modified Spalteholz technique and examined mesoscopically. Features of interest were photographed and then a limb from two pigs in each age group was cut into slabs and examined mesoscopically. The vascular supply of the distal part of the humerus was complex. It was supplied by vessels on both the cranial and caudal aspects and locally each aspect had a dual blood supply. Vessels anastomosed and on the cranial aspect formed a vascular ring. The proximal part of the ulna was supplied by vessels that were on its medial and lateral surfaces. The vessel on the lateral surface continued distally and supplied the lateral aspect of the proximal part of the radius. The proximal part of the radius was also supplied by arteries that were on the cranial and medial surfaces. Blood vessels provided branches to numerous cartilage canals of the articular-epiphyseal cartilage complexes, epiphyseal centres of ossification, and growth plates. The patterns of blood vessels in cartilage canals which were in sagittal or transverse planes were best exemplified by those in the distal part of the humerus. Perforating cartilage canals emerged from the epiphyseal centres of ossification. The pattern of cartilage canals was consistent in a general configuration, but individual variation did occur. Although cartilage canals were abundant in the youngest pigs, with increasing age the distribution of cartilage canals changed and the numbers of cartilage canals decreased.

The effect of a penetrating biodegradable implant on the growth plate. An experimental study on growing rabbits with special reference to polydioxanone

This study examined the fate of a biodegradable polydioxanone (PDS) implant in growing bone in rabbits. In 20 immature rabbits, a PDS rod 2.0 mm in diameter and 25 mm in length was driven into a drill hole of equal bore in the intercondylar portion of the right femur across the central portion of the growth plate. In another 25 immature rabbits, a PDS rod 3.2 mm in diameter and 25 mm in length was driven into a corresponding drill hole using the same technique. The follow-up intervals were three, six, 12, 24, and 36 weeks. The distal femoral growth plates of both femora were analyzed by roentgenographic, microroentgenographic, oxytetracycline-fluorescence, histologic, and histomorphometric studies. Histomorphometric studies showed clear changes at the site of injury and appeared to be an excellent means of providing an exact numerical description of the different cellular areas of the growth plate in experimental studies. A transphyseal PDS implant 2.0 mm in diameter did not cause any permanent growth disturbance of the femur in a growing rabbit. An implant 3.2 mm in diameter caused a growth disturbance similar to a drill hole of equal bore.

[Fractures in children]

Children's fractures can be divided into shaft fractures, epiphysiolysis and epiphyseal fractures. Shaft fractures always heal with conservative methods. Slight axis deviations and shortening will correct spontaneously, while fracture disease and pseudarthrosis are extremely rare. Nevertheless, acute complications such as compartment syndromes deserve special attention. Epiphyseal fractures call for anatomical reduction and foolproof fixation to prevent growth disturbance through partial or complete closure of the growth plate. Such growth disturbance is not to be expected in case of epiphysiolysis.

Morphometric analysis of cartilage canals in the developing mouse epiphysis

Cartilage canal development in the distal femoral epiphysis of 5- to 7-day-old mice can be divided into three stages as previously described [Cole and Wezeman, Am. J. Anat. 174: 119-129, 1985]. Using this model, a morphometric analysis of canal volume density at the three stages of development was performed and provided evidence that canal formation significantly exceeds epiphyseal growth. These data are consistent with initial canal formation by invasion rather than by inclusion.

Epiphyseal ossification centers in the assessment of fetal maturity: sonographic correlation with the amniocentesis lung profile

The epiphyseal ossification centers of the distal femur (DFE) and proximal tibia (PTE) appear and enlarge during the third trimester of pregnancy. Late in the third trimester, the epiphysis of the proximal humerus (PHE) begins to ossify in some fetuses. Using the amniocentesis lung profile to determine the value of sonographic epiphyseal visualization as a predictor of pulmonary maturity, we studied 50 fetuses prospectively and compared the sonographic epiphyseal findings with results from the amniocentesis lung profiles. Nine fetuses with a visible PHE had a mature amniocentesis lung profile (accuracy of positive prediction = 100%), and then fetuses with an immature amniocentesis lung profile had no visible PHE (conegativity = 100%). Fetuses in which the combined DFE and PTE diameters were greater than 11 mm or in which the DFE and the PTE diameters were similar in size (DFE less than or equal to 1 mm larger than PTE) also yielded positive results. Copositivity and accuracy of prediction of an immature amniocentesis lung profile, on the other hand, were low (22%-25%) for the same epiphyseal parameters. These data suggest that antenatal visualization and measurement of the epiphyseal ossification centers of the fetal knee and shoulder may help to identify fetuses that would have a mature amniocentesis lung profile.

The role of the epiphyseal and metaphyseal circulations on longitudinal growth in the dog: an experimental study

An experimental model using the immature canine proximal fibular epiphysis was developed to isolate and investigate the effects of the epiphyseal and metaphyseal circulations on longitudinal growth. Experimental constructs studied the epiphyseal circulation, the epiphyseal and metaphyseal circulations, a devascularized growth plate, and a control group. Twenty-four limbs were studied by serial x-ray films and microangiographic and histologic analyses at time of death, 24 weeks after surgery. The data from this preliminary study show that both metaphyseal and epiphyseal circulations are necessary for predictable longitudinal growth.

Vascular pattern of the developing proximal femur in the domestic fowl

The vascular pattern of the proximal femur and its importance in the aetiology of coxofemoral conditions has been established in many species, including man. In the avian femur, vascular lesions have been associated with pathological conditions. Ninety-six laying strain chicks were reared from day-old until 20 weeks. Birds were killed throughout the growth period and specimens were prepared for study. The origin and nature of epiphyseal vascular canals was established. Three principal stages of development occurred, namely growth plate formation, the growth period and the cessation of growth. Transphyseal vessels are described in the day-old chick to which a nutritive function is ascribed. Anastomosis did not occur between epiphyseal vascular canals. The epiphyseal vascular canals are grouped according to their source.

Effects of hot environments and carbonated drinking water on bone characteristics of eight-week-old broiler chicks

Epiphyses of the femura from 8-week-old broiler chicks were examined for morphology using scanning electron microscopy and for elemental composition using energy dispersive x-ray microanalysis. Birds between the ages of 4 and 8 weeks were subjected to either 25 or 35 C environments and given tap or carbonated drinking water. The morphological appearance of the epiphyses was affected by the kind of drinking water but not the thermal environment. Elemental constituents, however, were affected by both environmental temperature and drinking water.

Tibial epiphyseal development: a cross-sectional histologic and histomorphometric study in the New Zealand white rabbit

Sequential histomorphometric studies on the developing rabbit tibia from birth to skeletal maturity demonstrate that growth plate height lessens as longitudinal growth diminishes. Differing rates of development proximally and distally are documented. Distally, growth plate height, width, and area and total epiphyseal area peak or reach near maximum values by 3 weeks, whereas proximally, they do so by 8 weeks (except for height, which also peaks at 3 weeks). The distal growth plate is being obliterated by 16 weeks, at which time the proximal growth plate remains well structured and open. The distal tibia and fibula develop as one tissue mass. The articular cartilage and epiphyseal cartilage are continuous from birth, whereas a single ossification center and a single growth plate are present by 8 weeks. The data point to the presence of intrinsic growth plate, as well as systemic, control mechanisms affecting skeletal growth. Knowledge of temporal and quantitative features of epiphyseal and growth plate development will greatly aid in the elucidation of the underlying controls.

Epiphyseal union of the anterior iliac crest and medial clavicle in a modern multiracial sample of American males and females

Epiphyseal union of the anterior iliac crest and the medial clavicle is examined in 605 males and 254 females in a sample of modern Americans aged 11-40 years. The sample includes American whites, American blacks, Latin-Americans, and Orientals. This is the first skeletal investigation using a large sample of individuals of known age since the McKern and Stewart study of 1957. Epiphyseal union is analyzed in terms of four stages: 1) nonunion with no epiphyses, 2) nonunion with separate epiphyses, 3) partial union, and 4) complete union. The results provide broader age ranges for the stages of union than previous studies. Age ranges for males and females are similar or vary by only 1-2 years. Racially, no major distinguishing patterns are found except for greater variability in age distributions appearing to exist among American black females. The study furnishes valuable data on epiphyseal timing in the teenage years.

Discriminant function sexing of the tibia

The objective of the study was to test whether the shaft dimensions of the tibia were as sexually dimorphic as those of the femur and to develop a new sex determination technique from the tibia. Stepwise discriminant function subroutine based on a sample of 159 tibiae of blacks and whites of both sexes of the Terry Collection was employed for the study. Osteometric measurements included were the length, proximal and distal breadths, the circumference of the nutrient foramen and of the smallest shaft regions, and anteroposterior and transverse diameters at the nutrient foramen levels. The results indicated that in all dimensions proximal epiphyseal breadth and the minimum circumference were the variables selected by the stepwise function in blacks and that all but the transverse diameter participated in the function in whites. Average accuracy of sex determination was 87.3% for whites and 90.0% for blacks. For both races proximal epiphysis was a better indicator of sex differences than the remaining dimensions. While the study provided statistically reliable results sexual dimorphism was observed to be race dependent. This was especially true for blacks who provided higher prediction accuracy and more dimorphism than whites. Thus it was suggested that determination of sex required a consideration of not only growth related sex differences, and physical activity, but also the genetic (racial) nature of a population.

Aging and dietary modulation of rat skeleton and parathyroid hormone

Studies were carried out on SPF F344 male rats to evaluate the effects of aging and life-prolonging food restriction, without malnutrition, on rat skeleton and circulating PTH. Six-week-old F344 rats were divided into five groups. Group 1 rats were fed ad libitum a diet that contained 21% protein. Group 2 rats were fed 60% of the mean food intake of group 1 rats from 6 weeks of age for the rest of their lives. Group 3 rats were fed 60% of the ad libitum food intake until 6 months of age and then switched to ad libitum feeding. Group 4 rats were fed ad libitum until 6 months of age, and then switched to 60% of the ad libitum food intake. Group 5 rats were fed ad libitum a diet that contained only 12.6% protein so that these animals ingested the same amount of protein per day as the group 2 rats. In group 1 animals, bone length, weight, density, and calcium content increased rapidly with age and plateaued at about 12 months of age. There was no evidence of bone loss in these animals until about 24 months of age, but by 27 months, the animals had lost appreciable amounts of bone. The circulating immunoreactive PTH levels of the animals increased with advancing age, with a marked rise at 27 months. The age-related changes in bone and serum PTH levels of rats in groups 3 and 5 were similar to those of group 1 animals, except that a terminal increase in serum PTH did not occur in group 5 rats. In the groups 2 and 4 animals which were food restricted for the longest period, bone growth and maturation were slowed down, but the animals did not experience senile bone loss or marked terminal increase in circulating PTH. The salutary effects of food restriction were, therefore, not due specifically to the restriction of protein intake or to restricting food intake only during the period of rapid growth.

Pedicle graft epiphysis transplantation

Transfer of a graft taken from the iliac crest apophysis of 48 immature dogs was studied as a means of repairing an epiphysiodesis constituting more than 50% of the growth plate area. Four groups of dogs were studied. In Group I the graft was pedicled on the superficial circumflex iliac vessels and reimplanted in situ. In Group II the pedicled graft was transferred to the groin area as an island graft. These two control groups demonstrate the conservation of growth activity when the graft is pedicled on its epiphyseal vessels. In Group III the graft was transferred to the distal epiphyseal area of the femur after resection of the portion of the growth plate (approximately 2/3) located inside the perichondrial ring, with conservation of 80% of the outer portion of the cylinder. Microsurgical revascularization was achieved by using the saphenous vessels. In Group IV (the control group for Group III) the latter technique was used without revascularization. Roentgenography was performed for nine months after operation. The specimens were studied by tetracycline labeling and histologic and histochemical examinations. Results indicate that a well vascularized graft functions as a dynamic catalyst for regeneration of the resected portion of the growth plate and prevents the formation of bony bridges between the epiphysis and metaphysis by possible activation of the peripheral groove of Ranvier.