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PubMed1994

Periarticular hyperostosis and renal disease in six black lemurs of two family groups.

Proliferative periosteal disease was identified in 6 black lemurs (Eulemur macaco macaco) of 2 family groups. Bilaterally symmetric formation of periosteal new bone at the metaphyseal regions of major long bones was first detected at the stifle and tarsal areas and was detected later at the carpal areas. Bony changes were accompanied by progressive renal disease. The syndrome progressed for 6 to 16 months before the lemurs were euthanatized because of debility. Necropsy revealed changes confined to the skeleton and kidneys. Formation of new bone was detected at all affected joints, and chronic renal disease was evident in each lemur. A specific cause was not identified. Although indistinguishable histologically from hypertrophic osteoarthropathy, several important differences were apparent. Distribution of the periosteal new bone was in the metaphyseal rather than diaphyseal areas. Thoracic or gastrointestinal lesions, typically seen with hypertrophic osteoarthropathy, were not detected, and substantial renal disease was evident. A genetic component may be involved in the development of this condition.

Animals↗
PubMed1994

The vascular system of human fetal long bones: a scanning electron microscope study of corrosion casts.

The vascular system of the femur and humerus was investigated in 17-24 wk human fetuses by scanning electron microscopy of corrosion casts. The number of nutrient foramina present in both bones ranged from 1 to 3 and the number of nutrient vessels associated with individual foramina also varied. The medullary arteries supplied both the bone cortex and marrow. There was no arterial supply to the shaft cortex from the periosteal side, where only capillaries were found to enter the bone. The metaphyses were supplied and drained by conspicuous vascular triads composed of an artery and 2 veins. In the marrow cavity, 2 morphologically different areas of the fine vascular network could be distinguished: diaphyseal sinusoids and metaphyseal capillaries forming a 'vascular besom' which was abruptly demarcated by the growth plate cartilage. The cortical microvascular bed was composed of capillaries and more numerous irregular sinusoids. The 2 main vascular systems, nutrient and periosteal, were interconnected not only via the network of cortical capillaries/sinusoids, but also by larger arteries and veins traversing the cortex. The features of the vascular system of human fetal long bones suggest its considerable functional flexibility and its capacity to modify blood flow patterns depending on circumstances.

Arteries↗
PubMed1994

[The biological plate osteosynthesis].

The continually evolving understanding of bone biology and the analysis of clinical complications have led to a modified approach in internal fixation using plates. Anatomical reduction of the fragments in comminuted diaphyseal and metaphyseal fractures itself is no longer a goal. Important reduction aims are the correct length of the bone, and axial and torsional alignment. The preservation of the viability of the bone fragments is the key to unimpaired fracture healing. The primary stability of an osteosynthesis seems to be of minor importance for bone healing. More important is the rapid integration of unreduced but vital fragments into the fracture callus which buttresses the fracture area opposite the plate reducing the risk for overload and fatigue failure of the implant. Additional primary bone grafting leeds to local vascular disturbance of the bone and is rarely indicated. Indirect reduction technique with the aid of the fracture table or the distractor and a minimal but optimal use of implant material is the new concept to achieve undisturbed fracture repair in metaphyseal and diaphyseal fractures. In articular fractures the anatomic restoration of the articular surface can be obtained by the combination of indirect reduction technique (ligamentotaxis, soft tissue taxis) and accurate direct reduction of certain strategic fragments. Modifications of the plate design (limited contact, point contact) which minimize additional vascular damage to the bone help to accomplish this new concept.

Ankle Injuries↗
PubMedDate not supplied

Absence of lower extremity ossification centers in term infants with congenital syphilis.

Radiologic evaluation is valuable for confirmation of congenital syphilis. Bony abnormalities are thought to be secondary to active disease or a growth response of bone to systemic illness. Anteroposterior lower extremity radiographs of 85 euthyroid term infants (> or = 38 weeks' gestation; mean weight, 3244 gm; range, 1940-4380 gm) with presumptive congenital syphilis were evaluated for the presence of the distal femoral and proximal tibial secondary ossification centers and other bony abnormalities. Both proximal tibial and distal femoral ossification centers were absent in only 9 of 85 infants with syphilis; the proximal tibial center was absent in 26 of 85 (total 30.6%; 95% confidence limits 0.2 to 0.4). This observation is significant at the p < 0.01 level by chi-square analysis with use of historical controls. Periosteal new bone formation was seen in 2 of 85 infants. Metaphyseal lucent bands were present in 21 of 85 infants, 8 of whom also had absent lower extremity ossification centers. For comparison we reviewed lower extremity radiographs from 12 term infants without congenital syphilis. Ossification centers were absent in one growth-retarded infant, and metaphyseal lucent bands were found in one infant. Although standard texts report nearly universal ossification of the distal femoral epiphysis at term, we observed delayed skeletal maturation in 30.1% of term infants with congenital syphilis. We speculate that this delay may be reflective of systemic infection.

Chi-Square Distribution↗
PubMed1975

[Hypertrophic osteodystrophy of the dog (author's transl)].

The clinical and radiological findings of 21 dogs with hypertrophic osteodystrophy are described. In three cases a detailed pathologico-anatomic examination was performed also. The dogs concerned were young animals of large breeds with clinical symptoms of lameness, fever, pain, and thickened metaphyses of the long bones. Radiologically the condition was characterised by enhancement of the metaphyses and periosteal new growths of the bone. The pathologico-anatomic examination revealed a disturbed endochondral and periosteal ossification. Overnutrition as a possible cause of the condition is discussed.

Analgesics↗
PubMed1994

Variables affecting time to bone healing during limb lengthening.

Radiographs and charts of 114 consecutive patients who underwent 140 lower-extremity bone-segment lengthening procedures using the Ilizarov external fixator were reviewed. Patient age, bone segment (femur, tibia), corticotomy level (metaphyseal, diaphyseal, double level), and distraction gap (DG) were recorded. Distraction-consolidation time (DCT) was defined as the interval in months from the date of the corticotomy until the DG was healed according to radiographic and manual testing criteria. Distraction-consolidation time had a direct linear relationship with the magnitude of the DG. Distraction--consolidation time versus DG was significantly less for femoral than tibial lengthening. Patients 20 years and older healed slower than patients younger than the age of 20 years. Patients 20 to 29 years old healed faster than patients older than 30 years and slower than patients younger than 20 years. Diaphyseal lengthening healed more slowly than metaphyseal lengthening. Double-level lengthening reduced the DCT when the DG was greater than 4 cm. Distraction--consolidation index--DCT divided by DG--was not a constant. Distraction--consolidation index decreased with increasing DG. To facilitate prediction of bone-healing time, graphs were developed demonstrating the average treatment time +/- 2 SD expected for a specific amount of lengthening, considering the bone segment, the level of osteotomy, and the age of the patient.

Adolescent↗
PubMed1994

Mechanical forces as predictors of healing during tibial lengthening by distraction osteogenesis.

Direct axial loads were measured weekly during a 15% left tibial lengthening in 21 skeletally mature dogs using three in-line load cells mounted between the rings of an Ilizarov external fixator. The loads increased linearly over time to a maximum at the end of distraction (Week 4). The metaphyseal lengthening sites (mean, 155 N) generated significantly higher loads than diaphyseal sites (mean, 111 N). Stress was calculated by dividing measured load by the computed tomographic-measured cross-sectional area of each distraction osteogenesis site; the metaphyseal and diaphyseal groups demonstrated equal stress at each time point with a maximum of 47 N/cm2 at the end of distraction. Six premature consolidations occurred that demonstrated loads significantly greater than 200 N by Week 2 of distraction. Three nonunions occurred that had significantly lower loads measured by Week 3 of distraction (mean, 60 N or 26 N/cm2).

Animals↗
PubMed1993

Cementless total hip arthroplasty for congenitally dislocated or dysplastic hips. Technique for replacement with a straight femoral component.

A new straight cementless stem was used for replacement of 67 dislocated or severely dysplastic hips. There were 45 hips with complete dislocation, 27 of which were cases after Schanz osteotomy. Technical solutions for various deformities are presented here. The acetabular component was placed at the level of the original cotyloid cavity or some lower position. In hips after total dislocation a metaphyseal shortening osteotomy was combined with distal advancement of the greater trochanter with intact attachment of the abductor muscles. This method was appropriate also for the femora, where high-seated Schanz osteotomy was previously performed. If the diaphysis was too narrow for the stem, it was split about 10 cm both anteriorly and posteriorly. In cases with unilateral total dislocation where Schanz osteotomy had been seated low, metaphyseal segmental shortening with angular correction was performed and the stem was used as an intramedullary nail. Special attention was paid to achieve sufficient abduction strength to balance the pelvis and abolish Trendelenburg limp and to restore leg length. The clinical and radiographic results of the consecutive series were assessed three to five years after the arthroplasty. Pain relief and the functional results including improvement of gait were generally good, primary complications were few, but the loosening and revision rate of the smooth-threaded acetabular component was unacceptably high. There were no problems with the press-fit cups. In general the outcomes were good even when reoperation was required.

Adult↗
PubMed1993

Pilon fractures of the distal tibia.

Pilon fractures are relatively rare fractures of the distal metaphysis of the tibia resulting from axial and/or rotational forces. They involve varying degrees of metaphyseal disruption, articular damage, and malleolar displacement. When severe, these injuries represent a tremendous challenge to the orthopaedic trauma surgeon. Traditional treatment of high-grade pilon fractures by closed means has led to unsatisfactory results. Open reduction and internal fixation in accordance with AO/ASIF principles has greatly improved the outcome in these often disabling fractures. Surgical technique involves anatomic restoration of fibular length, reconstruction of the plafond, bond grafting of the metaphyseal defect, and buttress plating of the medial tibia. Thorough preoperative planning and meticulous surgical technique produce predictably good results in the majority of cases.

Ankle Injuries↗
PubMed1993

The effect of gallium nitrate on healing of vitamin D- and phosphate-deficient rickets in the immature rat.

The effect of gallium on rapid in vivo mineralization was studied in a rachitic rat model in which rickets were induced in immature rats then reversed ("healed") with repletion of vitamin D and phosphate. Gallium was administered to selected groups of animals before and during the healing phase. In nonrachitic animals and rachitic animals before healing, the mineral content of diaphyseal and metaphyseal bone was increased, and the crystal size was decreased in those animals that received gallium compared with those that did not. Mineralization of the undermineralized osteoid appeared histologically normal by 72 hours in all animals. However, animals that received gallium both before and during the healing phase had less well-mineralized bones at 18 hours, and by 72 hours, they had lesser increases in osteocalcin and mineral content, which was associated with smaller crystal sizes, than did any animal that did not receive gallium at any time. Prior to the healing phase, the ratio of gallium to hydroxyproline in the metaphyses of rachitic animals was similar to that in nonrachitic animals. Likewise, this ratio did not change in the animals receiving gallium both before and during the healing phase. The ratio of gallium to calcium was higher in rachitic animals compared with controls, and this ratio lowered significantly by the end of the healing phase. Results may be explained in part by direct effect of gallium on the physical process of mineral formation during the rapid healing phase as well as by effects of gallium on osteoblasts and osteoclasts during the induction of rickets.

Alkaline Phosphatase↗
PubMed1993

Skeletal dysplasia in perinatal lethal osteogenesis imperfecta. A complex disorder of endochondral and intramembranous ossification.

Osteogenesis imperfecta (OI) Type II is a rare heritable disorder of bone matrix that results in catastrophic congenital skeletal dysplasia. Two cases of OI Type II had symmetric rhizomelic skeletal dysplasia apparent on ultrasound at 16 and 20 weeks' gestation. Histologic and histochemical studies performed on skeletal tissue from fetal autopsies showed the following: (1) abnormal growth plate tissue characterized by failure of formation of primary bony spongiosa; (2) persistence of calcified cartilage bars in the diaphysis; (3) metaphyseal microfractures; (4) abundant cartilaginous fracture callus; (5) absence of bony callus; (6) failure of formation of intramembranous cortical diaphyseal bone; (7) angulation of long bones in portions of the metadiaphyses bordered by fracture callus; and (8) mechanical failure of the perichondral ring of LaCroix with a normal fibrous ossification groove of Ranvier. These findings suggest that skeletal dysplasia in OI Type II results from the action of muscular forces on a skeleton weakened by a complex disorder of endochondral and intramembranous ossification. The paucity of primary metaphyseal trabeculae and subperiosteal cortical bone leads to pathologic fractures of the immature fiber bone and an imperfect attempt at fracture repair. Angulation and shortening of long bones occurs between numerous sites of focal endochondral fracture callus. Mechanical failure of the fibrous perichondral ring leads to further collapse and shortening without obvious functional impairment of the fibrous ossification groove. Perinatal lethal OI provides insight into how a molecular disorder predominantly of Type I collagen metabolism results in pathology of numerous tissues, leading to severe skeletal dysplasia without primarily affecting chondrogenesis.

Bone Diseases, Developmental↗
PubMedDate not supplied

Intraosseous infusions: effects on the immature physis--an experimental model in rabbits.

Intraosseous infusions are becoming more popular in critical care and emergency room settings in pediatric patients. Spinal needles are introduced in metaphyseal bone to establish intravenous (i.v.) access when standard i.v. routes are not accessible. An experimental rabbit model was constructed to simulate intraosseous infusion in human infants to determine effects on the physis and growth rate of the infused bone. Twenty immature rabbits were infused with saline, bicarbonate, or dopamine solutions. Rabbits were killed and tibias harvested at 24 h and 3 weeks, and gross and histologic sections were examined. No growth disturbance occurred in any of the infused tibias. Gross and microscopic changes were confined to metaphyseal bone and had completely resolved after 3 weeks. There was no evidence of physeal injury.

Animals↗
PubMed1993

[Tissue reaction after implantation of sintered porous hydroxyapatite in the distal metaphysis or epiphysis of the femur of rabbits].

The present investigator implanted sintered porous hydroxyapatite rod (phi 3 mm x 10 mm) in the distal metaphysis or epiphysis of the right femur of 40 Japanese white rabbits and studied tissue reaction around hydroxyapatite (abbreviated as HAp) with radiograms and microphotographs. As control, stainless-molybdenum alloyed (abbreviated as SMO) rod was used. In the groups with metaphyseal implantation of HAp or SMO, the distance between the center of implant and the distal femoral epiphyseal line increased during 12 weeks after operation. New bone was directly bonded to implanted material only after implantation of HAp. Ratio of length of HAp bone interface and length of HAp circumference was greater in the groups with implantation in the metaphysis 2 weeks after operation than those in the epiphysis. On the other hand, it was greater in groups with implantation in the epiphysis than those in the metaphysis 12 weeks after operation. In the groups with metaphyseal implantation of HAp, the ratio in groups 2 weeks after operation was greater than that in 12 weeks and there was a firm interrelationship between the ratio and the distance between the center of implant and the distal femoral epiphyseal line.

Animals↗
PubMedDate not supplied

[Effect of space flight on rat skeletal bones (an optical light and electron microscopic study)].

By light and electron microscopy long tubular bones of white Wistar rats were examined after a 22-day space flight and ground-based synhcroneous experiment. Approximately half of the flight rats showed loosened spongiose of metaphyses which was normally combined with a reduced area of the primary spongiose near the cartilaginous growth plate. This was suggestive of inhibited growth of bones in-flight. The light and electron microscopic examination of bones of flight rats revealed wide osteocyte cavities (lacunae) that could be associated with perilacunar osteolysis. The study of synchroneous animals demonstrated a less expressed spongiose of metaphyses found only in one third of the rats which was not usually combined with a reduced area of the primary spongiose near the cartilaginous growth plate. The histological examination of bones of flight rats on the 27th postflight day indicated that that period of time was insufficient for the normalization of all the changes.

Animals↗
PubMed1993

Torsional fixation of a modular femoral hip component.

Standard range of motion (S-ROM) modular total hip femoral stem has been designed to achieve precise fit in the diaphysis and metaphysis. This study compares torsional fixation of the S-ROM stem implanted with tight fixation of both the metaphyseal and diaphyseal components, tight metaphyseal and loose diaphyseal fixation. The mean load to failure was significantly greater in those implanted with tight fixation proximally and distally. Rotational micromotion was significantly decreased by fixation proximally, but permanent rotational displacement was improved primarily by distal fixation. Tight proximal and distal fixation were necessary to control both micromotion and permanent rotational displacement caused by torsional loading. Clinical success of this implant will depend on achieving tight proximal and distal fixation.

Biomechanical Phenomena↗
PubMed1995

Electrical stimulation of bone nonunion with the presence of a gap.

A total of 22 established nonunions was treated with a capacitively-coupled electrical signal. A gap of 0.5 cm or more between the fragments was present in all of these nonunions. After an average of 26 weeks of treatment with capacitive coupling, radiographic assessment showed solid bone union in 72.7% of the cases. The results were better when the fracture site was metaphyseal. When the site was diaphyseal, bone healing was mainly achieved by bone trabeculae invading the gap. When the site was metaphyseal, healing occurred by the formation of a peripheral callus. The results were not affected by the presence of infection. In 8 of the cases osteomyelitis occurred, but all healed.

Adolescent↗
PubMed1995

Radiologic manifestations of osteopetrosis.

The clinical radiologic manifestations of 8 patients with osteopetrosis (4 males and 4 females) are analyzed. Six of the cases are benign. The pathologic basis for the radiologic manifestations is discussed, and a classification is suggested. "Broom-like" metaphyses, metaphyses containing three or four dense layers of bone, and ossification of soft tissues around joints were found and differential diagnosis was made.

Adolescent↗
PubMed1995

[Combination of the Ilizarov ring fixator with the unilateral AO tube fixator. Initial clinical experiences with the hybrid system].

Ring fixation of the tibia is difficult because of soft tissue transfixation and the size and weight of the external fixator. To increase the patients comfort K-wire and half-pin fixation are combined in a new hybrid configuration. The Ilizarov ring fixator with K-wire or Schanz screw fixation is combined with the unilateral AO fixator. This configuration has so far been used in 17 cases: in the proximal and intraarticular tibia in 7 cases, in the distal tibia in 8 cases and in the femur in 2 cases. As experience with the hybrid system widens indications accepted are metaphyseal and intraarticular fractures of the tibia with severe soft tissue damage, open fractures, segmental defects and fractures of the tibia that cannot be nailed. Loosening of the hybrid construction requiring an additional operative procedure has not occurred. The hybrid system is minimally invasive and allows early weight-bearing. It has the advantages of less transfixation of the soft tissue, an easy operative technique and more comfort with higher patient compliance, and the options for corrective procedures are the same as with the conventional Ilizarov technique. Our preliminary first experience with this system is encouraging; it is especially useful for problematic epi- and metaphyseal fractures with severe soft tissue damage.

Adult↗