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PubMed1991

Calcium absorption and osseous organ-, tissue-, and envelope-specific changes following ovariectomy in rats.

Because cancellous bone loss occurs following ovariectomy (OVX) in rats, this has become a popular model to explore therapeutic modalities for postmenopausal bone loss in humans. The purpose of this study was to determine intestinal calcium absorption in situ and organ-, tissue-, envelope-, and site-specific changes in osseous tissues at six weeks after OVX in rats using chemical, biochemical, absorptiometric, microradiographic, and morphometric methods. There were no changes in intestinal absorption of calcium, but duodenal weight per length was significantly increased in the OVX animals compared with age-matched, sham-operated controls. There was an increase in wet bone weight, but decreases in ash/dry bone weight, total bone Ca, and Ca per ash weight in the OVX animals. There were significant decreases in the OVX animals in metaphyseal bone mineral content, as determined by photon absorptiometry and metaphyseal cancellous bone volume. The perimeter to area ratio of the metaphyseal cancellous bone in the OVX animals was increased compared with controls. Endochondral growth rates were increased in the OVX animals, attributable to an increased growth plate hypertrophic cell size and rate of chondrocyte proliferation. In the OVX animals there was an increase in modeling in the formation mode of the periosteal surface at the tibio-fibular junction. Increased periosteal modeling in the formation mode was also observed in the body of the mandible, suggesting that the changes in periosteal bone formation are not strictly coupled with changes in endochondral growth. There was an increase in modeling in the resorption mode of the endocortical surface at the tibio-fibular junction in the OVX animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed2005

Differential turnover of cortical and trabecular bone in transgenic mice overexpressing cathepsin K.

Cathepsin K is a major osteoclastic protease. We have recently shown that overexpression of mouse cathepsin K gene in transgenic UTU17 mouse model results in high turnover osteopenia of metaphyseal trabecular bone at the age of 7 months. The present report extends these studies to a systematic analysis of cortical bone in growing and adult mice overexpressing cathepsin K. Mice homozygous for the transgene locus (UTU17+/+) and their control littermates were studied at the age of 1, 3, 7, and 12 months. Bone properties were analyzed using peripheral quantitative computed tomography (pQCT), histomorphometry, histochemistry, radiography, and biomechanical testing. In addition, the levels of biochemical markers of bone turnover were measured in the sera. Unexpectedly, cortical thickness and cortical bone mineral density were increased in the diaphyseal region of growing and adult UTU17+/+ mice. This was associated with an increased number of vascular canals leading to increased cortical porosity in UTU17+/+ mice without changes in the ultimate bending force or stiffness of the bone. In UTU17+/+ mice, osteopenia of metaphyseal trabecular bone was observed already at the age of 1 month. In sera of 1-month-old UTU17+/+ mice, the activity of tartrate-resistant acid phosphatase 5b was decreased and the levels of osteocalcin increased. Our results support the role of cathepsin K as a major proteinase in osteoclastic bone resorption. Excessive production of cathepsin K induced osteopenia of metaphyseal trabecular bone and increased the porosity of diaphyseal cortical bone. The increased cortical thickness and bone mineral density observed in diaphyses of UTU17+/+ mice demonstrate the different nature and reactivity of trabecular and cortical bone in mice. These results suggest that the biomechanical properties of cortical bone are preserved through adaptation as outlined in Wolff's law.

Animals↗
PubMed2004

Volar Barton's fractures with concomitant dorsal fracture in older patients.

PURPOSE: To describe a variant of Barton's volar articular shearing fracture of the distal radial articular surface with a subtle concomitant fracture of the dorsal metaphyseal cortex. METHODS: This fracture pattern was observed in 6 women and 2 men with an average age of 67 years (range, 58-76 years). All 8 patients were treated with a volar plate and screws. The dorsal metaphyseal fracture was not recognized in 5 patients and a volar buttress plating technique using an intentionally undercontoured volar plate was used. In 3 patients the dorsal fracture line was identified before surgery and the plate was contoured to fit the volar surface of the distal radius. RESULTS: All 5 patients treated with an undercontoured plate had loss of the normal palmar tilt of the distal radius (average,-9.4 degrees; range, 0 degrees to-22 degrees ) and dorsal translation of the distal radial articular fragments. For the entire group the palmar tilt averaged-5.9 degrees (range, 0.0 degrees to-22.0 degrees ), the ulnar inclination 19 degrees (range, 10 degrees -23 degrees ), and the ulnar variance-0.9 mm (range, 0.0 to-3.0 mm). All patients attained forearm supination of 80 degrees and the average pronation was 75 degrees (range, 45 degrees -80 degrees ). According to Sarmiento's modification of the system of Gartland and Werley there were 1 excellent, 6 good, and 1 fair results. The average Patient-Rated Wrist Evaluation score was 16 (range, 0-35). CONCLUSIONS: Some fractures with an oblique volar marginal articular fracture of the distal radius and volar radiocarpal subluxation (known as Barton's fracture) may also have a fracture through the dorsal metaphyseal cortex. Failure to identify this fracture line can lead to dorsal translation and angulation of the distal radius articular surface, particularly when an undercontoured volar plate is used for internal fixation.

Aged↗
PubMed1981

Production of collagenase inhibitor by the growth cartilage of embryonic chick bone: isolation and partial characterization.

Production of collagenase and collagenase inhibitors by the explants of epiphyseal, metaphyseal and diaphyseal regions of embryonic chick limbs during development has been investigated. Collagenase-inhibitory activity was first detected in the culture medium of the diaphyseal region of limbs at stage 36 where cartilage matrix erosion began to occur. However, neither active nor latent collagenase was detected in the media of any regions examined. At stage 38 and later, the maximum production of the inhibitory activity was observed in the explants of metaphyseal region (growth cartilage), while collagenase production was only in the diaphyseal region. Two collagenase inhibitors were isolated and purified approximately 150 fold from the culture medium of stage 38 and 43 metaphyseal regions of limbs by anion- and cation-exchange chromatography followed by gel filtration. The inhibitors are cationic proteins with the same molecular weight of approximately 25,000, but slight difference in molecular charge. They are heat-stable and inhibit collagenases from tadpole skin, chick bone and skin and human granulocytes and gelatinases from human granulocytes and chick skin as well as trypsin, but not Clostridium histolyticum collagenase. A possible function of the inhibitors in multistep regulations of the collagen-degrading enzyme system at the region of osteo-chondral transition is discussed.

Animals↗
PubMedDate not supplied

Subchondral magnetic resonance imaging changes in early osteoarthrosis associated with tibial osteonecrosis.

SUMMARY: The authors report on 41 patients with acute or subacute knee pain and early or midstage degenerative arthrosis with osteonecrotic lesions in the subchondral and metaphyseal region of the medial proximal tibia. Each lesion was identified only on magnetic resonance images (MRI). These MRI changes are classified and the clinical course is defined during a follow-up period averaging 4.5 years. Radiographically, 22 patients had minimal degenerative changes; 12 had moderate arthritis; and 7 were normal. With MRI, 3 distinct types of lesions were identified. Type A lesions had localized areas of decreased signal in the subchondral area. Type B lesions had diffuse signal changes with extension into the metaphysis. Type C lesions had metaphyseal involvement as well as a marginated serpentine subchondral rim usually associated with advanced osteonecrosis. There were 9 type A lesions, 23 type B, and 9 type C. At the end of 1 year, 33 patients (80%) had no or mild symptoms, and 8 (20%) had persistent moderate pain. At 4.5-year follow-up, most patients had symptoms consistent with progressive osteoarthrosis, 12 patients had severe symptoms (29%), 17 (41%) had mild or moderate symptoms, and only 12 (29%) were asymptomatic or had minimal symptoms. The type of MRI change seen initially was predictive of prognosis. Only 6 (19%) of the 32 patients with type A or B findings had severe symptoms at last follow-up. Six (66%) of the 9 patients with a type C MRI lesion had severe symptoms or had an operation by last follow-up. Twelve patients had follow-up MRI at a mean 15 months (range, 12 to 18 months) after the initial evaluation. The type A and B changes were either absent or significantly reduced. The type C subchondral marginated rim changes remained but metaphyseal involvement was reduced. There appears to be a spectrum of tibial subchondral MRI changes associated with sudden onset of medial knee pain in patients with early osteoarthritis of the knee. These changes may be indicative of osteonecrosis. The initial MRI classification is useful in predicting prognosis. Recognition of this problem may avoid unnecessary intra-articular surgery.

Aged↗
PubMed1999

Femoral bone blood flow after reaming and intramedullary canal preparation: a canine study using laser Doppler flowmetry.

This study was conducted to determine the effect of intramedullary reaming and canal preparation on bone blood flow in the proximal femur. Thirty-five adult dogs were randomly assigned to have their intramedullary canals prepared after reaming in the following manner: group 1, ream only; group 2, lavage; group 3, methylmethacrylate cement introduction; group 4, cement pressurization after placing a cement restrictor; group 5, lavage then cement introduction; and group 6, lavage then cement pressurization. Bone blood flow was measured at both metaphyseal and diaphyseal sites by using laser Doppler flowmetry before reaming, after reaming, after lavage, after cementing, and at 6 weeks after the procedure just before euthanasia. Reaming significantly decreased bone blood flow in the diaphysis (P = .046) but not in the metaphysis. Cement introduction and cement pressurization both significantly decreased bone blood flow in the metaphysis (P = .035, P = .004) and diaphysis (P = .007, P = .029). Pressurization of cement had a significantly greater relative effect than cement introduction alone in the diaphysis (P = .006) but not in the metaphysis. Lavage had no effect on bone perfusion. Bone blood flow was significantly increased at 6 weeks after the initial procedure in both the metaphysis (P = .049) and the diaphysis (P = .004). The results suggest that reaming decreases diaphyseal cortical but not metaphyseal bone blood flow significantly, whereas lavage has no effect. Cement introduction with or without pressurization has a significant detrimental effect on metaphyseal and diaphyseal blood flow. These findings have implications for intramedullary nailing and for canal preparation when performing arthroplasty.

Animals↗
PubMed2002

Human fetal bone development: histomorphometric evaluation of the proximal femoral metaphysis.

Quantitative data on metaphyseal bone histology during early human development are scarce. In the present study the proximal femoral metaphysis of 35 fetuses and newborns (gestational age 16-35 weeks) was analyzed by histomorphometry. Averaged over the entire metaphyseal area, the relative amount of bone and cartilage was higher in the third compared to the second trimester. Osteoid thickness increased with gestational age, whereas indices of bone resorption decreased. The relative amount of cartilage decreased with increasing distance from the growth plate, whereas the relative amount of bone increased. This was due to trabecular thickening, which occurred at an estimated rate of 3 microm/day in areas close to the growth plate. Despite this rapid rate of net bone gain, osteoid indices were relatively low, indicating that mineralization occurred very rapidly after bone deposition. These observations suggest that modeling, not remodeling, is the predominant mechanism responsible for the development of femoral metaphyseal cancellous bone in utero.

Analysis of Variance↗
PubMed1999

Bone metabolism and bone mineral density in childhood hypophosphatasia.

Childhood hypophosphatasia (HP) is an inborn error of bone metabolism, characterized by a reduced tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Bone mineral density (BMD) in childhood HP has not been reported so far. We measured BMD, in addition to markers of bone metabolism, in 6 boys with childhood HP (age 2-13 years) and in 10 parents and one sibling, each carrying the autosomal-recessive trait. BMD, measured by peripheral quantitative computed tomography (pQCT) and by dual-energy X-ray absorptiometry (DXA), was expressed as standard deviation from the normal mean (Z scores) and compared with bone mineralization by standard X-rays of the same locations. HP was confirmed by low TNSALP and its elevated substrates. In patients, BMD of the total body or spine, measured by DXA, was in the lower normal range. Total BMD of the distal metaphyses of the radius, measured by pQCT, was normal (Z score: mean +1.5). However, trabecular BMD of both radius (Z score: mean +4) and femur was grossly elevated. In parallel, X-rays showed reduced transradiancy of the radial and femoral metaphyses in all patients. In parents of patients with HP, BMD was in the lower normal range. Only one father had a decreased lumbar BMD. The discrepancy in BMD between cortical and trabecular bone of the metaphyses in patients was not present in their relatives. TNSALP levels in all first degree relatives were just below or in the lower normal range. The markers of bone turnover hydroxyproline and free deoxypyridinoline in urine were normal in patients and relatives. Hypermineralization/sclerosis of trabecular bone might serve as a compensation for a mechanically incompetent bony structure due to an impaired mineralization of cartilage caused by the genetic deficiency of alkaline phosphatase.

Absorptiometry, Photon↗
PubMed2001

Stimulatory effect of menaquinone-7 (vitamin K2) on osteoblastic bone formation in vitro.

Menaquinone-7, which is vitamin K2 (menatetrenone) with seven isoprene units, is highly contained in the fermented soybean. The effect of menaquinone-7 (MK-7) on osteoblastic bone formation was investigated. Femoral-diaphyseal and metaphyseal tissues of young male rats (4 weeks old) were cultured for 48 h in a medium containing either vehicle or MK-7 (10(-7)-10(-5) M). Calcium content, alkaline phosphatase activity, and deoxyribonuclic acid (DNA) content in the diaphyseal and metaphyseal tissues was significantly increased in the presence of MK-7 (10(-6) and 10(-5) M). The effect of MK-7 in increasing the diaphyseal and metaphyseal calcium content and alkaline phosphatase activity was completely prevented in the presence of cycloheximide (10(-6) M), an inhibitor of protein synthesis. Moreover, osteoblastic MC3T3-E1 cells after subculture were cultured for 24 h in a serum-free medium containing MK-7 (10(-7)-10(-5) M). Protein content, alkaline phophatase activity, osteocalcin and DNA content in the cells was significantly increased in the presence of MK-7 (10(-6) and 10(-5) M). The effect of MK-7 in increasing protein content, alkaline phosphatase activity, and osteocalcin production in the cells was completely blocked by cycloheximide. This study demonstrates that MK-7 has an anabolic effect on bone tissue and osteoblastic MC3T3-E1 cells in vitro, suggesting that the compound can stimulate osteoblastic bone formation.

Alkaline Phosphatase↗
PubMed2003

Inhibitory effect of menaquinone-7 (vitamin K2) on the bone-resorbing factors-induced bone resorption in elderly female rat femoral tissues in vitro.

The inhibitory effect of menaquinone-7 (MK-7; vitamin K2) on osteoclast-like cell formation and osteoclastic bone resorption in vitro is found (Mol Cell Biochem 228: 39-47, 2001). This study, furthermore, was undertaken to determine the effect of MK-7 on the bone-resorbing factor-induced bone resorption using the femoral-diaphyseal and -metaphyseal tissues obtained from elderly female rats in vitro. Femoral-diaphyseal and -metaphyseal tissues were cultured for 48 h in Dulbecco's modified Eagle's medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. The experimental cultures contained MK-7 (10(-7)-10(-5) M). The bone-resorbing factors, parathyroid hormone (1-34) (PTH; 10(-7) M) and prostaglandin E2 (PGE2; 10(-5) M), caused a significant decrease in calcium content in the diaphyseal and metaphyseal tissues. The PTH or PGE2-induced decrease in bone calcium content was completely inhibited in the presence of MK-7 (10(-7)-10(-5) M). In addition, MK-7 (10(-7)-10(-5) M) completely prevented the PTH (10(-7) M)- or PGE2 (10(-5) M)-induced increase in medium glucose consumption and lactic acid production by bone tissues. These results support the view that MK-7 has a direct inhibitory effect on the bone-resorbing factor-induced bone resorption in bone culture using female aged femoral tissues in vitro.

Aging↗
PubMed2003

Bilayered calcium phosphate coating to promote osseointegration of a femoral stem prosthesis.

A bilayered bioactive-gradient coating, consisting of a superficial layer of biphasic calcium phosphate (BCP) and a deep layer of hydroxyapatite (HA), promotes faster osseointegration and higher shear strength in non-loading conditions than do monolayer BCP or HA coatings. This study evaluated the biofunctionality of this coating in weight-bearing conditions at 6 and 12 months. The coating was plasma-sprayed on the metaphyseal portion of a sandblasted Ti6Al4V canine femoral prosthesis implanted using the surgical press-fit technique. An identical uncoated stem served as the control. Metaphyseal bone-to-implant apposition was increased for coated ( approximately 90% and 80% respectively at 6 and 12 months) as compared to uncoated implant ( approximately 7% at 6 and 12 months). Limited bone apposition was observed at the diaphyseal level. After 12 months, the uncoated implant interface consisted of well-organized, active fibrous tissue, whereas only inactive fibrous tissue interposition was observed at diaphyseal levels of the coated implant. At 6 months, the mineralization apposition rate (MAR) was similar, regardless of implant or bone structures. At 12 months, a significant decrease of MAR was observed around the uncoated implant. Transmission electron microscopy studies of the interface showed precipitation of biological apatite crystals in close association with mineralized collagenous bone matrix. Our results suggest a direct relationship between bioactivity and enhanced bone formation. The sandwich coating used is effective in promoting massive metaphyseal osseointegration, which ensures mechanical stability for early weight-bearing and should prevent long-term complications.

Journal Article↗
PubMedDate not supplied

Comparison of insertion time and pullout strength between self-tapping and non-self-tapping AO 4.5-mm cortical bone screws in adult equine third metacarpal bone.

OBJECTIVE: To compare screw insertion characteristics and pullout mechanical properties between self-tapping (ST) and non-self-tapping (NST) AO 4.5-mm cortical bone screws in adult equine third metacarpal bone (MC3). STUDY DESIGN: In vitro biomechanical experiment. ANIMALS OR SAMPLE POPULATION: Seven pairs of adult equine MC3. METHODS: Bicortical holes were drilled transversely in proximal metaphyseal, diaphyseal, and distal metaphyseal locations of paired MC3. NST screws were inserted in pre-tapped holes in 3 sites of one bone pair, and ST screws were inserted in non-tapped holes of contralateral MC3. Tapping and screw insertion times and maximum torques were measured. Screw pullout mechanical properties were determined. RESULTS: Screw insertion time was longer for ST screws. Total time for tapping and insertion (total insertion time) was over twice as long for NST screws. Statistically significant differences were not observed between screws for any pullout mechanical property. From pullout tests, diaphyseal locations had significantly stiffer and stronger structure than metaphyseal locations. Pullout failure more commonly occurred because of screw breakage than bone failure. Bone failure and bone comminution were more commonly associated with ST screws. Bone failure sites had pullout failure loads that were 90% of screw failure sites. CONCLUSIONS: NST and ST 4.5-mm-diameter cortical bone screws have similar pullout mechanical properties from adult equine MC3. ST screws require less than half the total insertion time of NST screws. CLINICAL RELEVANCE: Use of ST 4.5-mm-diameter cortical bone screws should be considered for repair of adult equine MC3 fractures; however, bone failures at screw sites should be monitored.

Animals↗
PubMed1991

[The skeletal changes in premature infants with a copper deficiency].

We describe 5 preterm infants (25th to 30th week of gestation) suffering from alimentary copper deficiency. The diagnosis was confirmed by low serum copper and caeruloplasmin concentrations. Characteristic clinical findings were repeated apnoeic attacks, hypopigmentation of skin and hair, anaemia, neutropenia and leucopenia refractory to other therapy, as well as increasing serum alkaline phosphatase activity in the first month of life. Starting in the 3rd to 12th week of life the radiographic findings were general skeletal osteoporosis and retardation, metaphyseal radiodense lines, irregular metaphyses, cupping and spurring of the metaphyses, followed by multiple fractures and subperiosteal new bone formation and enlarged costochondral junctions. Copper was substituted orally resulting in complete healing of fractures and improvement in both clinical symptoms and laboratory parameters.

Administration, Oral↗
PubMed1999

Cytochemical demonstration of the glucocorticoid receptor in skeletal cells of the rat.

The in vivo localization of the glucocorticoid receptor (GR) was studied in cartilage and bone cells of femurs of young adult rats. Deparaffinized sections were treated with a polyclonal antibody raised against the amino-terminus of human GR; the immunoreaction was detected with the streptavidin-biotin amplification method. Histomorphometric, computer-assisted analysis of GR-positive cells was performed by counting the percentage of GR-immunostained cells in the proliferative and maturative/hypertrophic zone of the epiphyseal growth plate cartilage, and of the percentage of positive osteoblasts (OBs), osteoclasts (OCLS) and osteocytes (OCs) in the metaphyseal secondary ossification zone. Numbers of OBs and OCLs per mm of metaphyseal endosteal perimeter, and numbers of OCs per mm2 of trabecular area were also counted. Immunopositive cells were found both in cartilage and bone, with variable degree of nuclear and/or cytoplasmic immunostaining; immunonegative cells were present among the positive ones. Histomorphometry showed that about 54% of chondrocytes in the proliferative zone, and 55% of chondrocytes in the maturative/hypertrophic zone of the growth plate were labeled; in metaphyseal bone, 68% of OBs, 65% of OCs, and 98% of OCLs were GR-positive. The density of positive cells was 12.06 OBs/mm, 3.32 OCLs/mm, and 520.40 OCs/mm2. These results, for the first time obtained in vivo, show that GR is present in cartilage and bone cells, and that the degree of GR-immunostaining is variable in the same type of cell. This may be dependent on the cell cycle and stage of differentiation, and may reflect a variable cellular sensitivity to the stimulation of the glucocorticoid hormone.

Animals↗
PubMed2004

Cancellous bone changes in the radius of patients with rheumatoid arthritis: a cross-sectional quantitative macroradiographic study.

OBJECTIVE: Fractal signature analysis (FSA), a computerized method of textural analysis, permits the separate measurement of changes in vertical and horizontal trabeculae based on the fractal dimension over a range of trabecular widths (fractal signature). We determined whether the FSA of high-definition macroradiographs (x5 magnification) quantified radiographic changes at sites of osteopenia and erosion formation in the rheumatoid arthritis (RA) hand. METHODS: Sixty-seven RA patients had macroradiographs of the left wrist and hand. The distal radius was scored and grouped from very mild (RA1) to moderate (RA4) disease. Macroradiographs were digitized and FSA of horizontal and vertical trabecular organization was performed in the radius at sites of periarticular osteopenia, erosion formation and at a mid-metaphyseal site. The RA groups were compared with 11 healthy non-arthritic subjects using ANOVA and Dunnett's tests. RESULTS: Compared to the non-arthritic hands, FSA at the distal radius in groups RA1 to RA4 measured significantly lower (P<0.05) fractal signatures. The fractal signatures were lowest in RA4 involving small, medium to large sized vertical trabeculae at the periarticular osteopenic (0.18 to 0.84 mm, P<0.01) and mid-metaphyseal sites (0.12 to 0.60 and 0.84 to 1.02 mm, P </= 0.04), and small to medium sized vertical trabeculae at the periarticular erosion site (0.24 to 0.84 mm, P<0.01). CONCLUSION: FSA quantified radiographic bone loss in the distal radius of RA patients with increasing radiographic severity in terms of lower fractal signatures compared with the non-arthritics. Disease-related bone loss was demonstrated by FSA to involve mainly vertical trabeculae at the periarticular osteopenic, periarticular erosion and the mid-metaphyseal sites indicating directionality of bone resorption in RA.

Arthritis, Rheumatoid↗
PubMed1990

Cosmos 1887: morphology, histochemistry, and vasculature of the growing rat tibia.

Light microscopy, electron microscopy, and enzyme histochemistry were used to study the effects of spaceflight on metaphyseal and cortical bone of the rat tibia. Cortical cross-sectional area and perimeter were not altered by a 12.5-day spaceflight in 3-month-old male rats. The endosteal osteoblast population and the vasculature near the periosteal surface in flight rats compared with ground controls showed more pronounced changes in cortical bone than in metaphyseal bone. The osteoblasts demonstrated greater numbers of transitional Golgi vesicles, possibly caused by a decreased cellular metabolic energy source, but no difference in the large Golgi saccules or the cell membrane-associated alkaline phosphatase activity. The periosteal vasculature in the diaphysis of flight rats often showed lipid accumulations within the lumen of the vessels, occasional degeneration of the vascular wall, and degeneration of osteocytes adjacent to vessels containing intraluminal deposits. These changes were not found in the metaphyseal region of flight animals. The focal vascular changes may be due to ischemia of bone or a developing fragility of the vessel walls as a result of spaceflight.

Alkaline Phosphatase↗
PubMed2001

Natural progress of a bone scan after cementless hydroxyapatite-coated total hip arthroplasty.

To establish the natural progress pattern of postoperative bone uptake, a periprosthetic quantitative technetium-99m methylene diphosphonate scintiscan was done on 80 asymptomatic hips (62 patients) with uncomplicated cementless hydroxyapatite-coated total hip arthroplasties and 20 healthy control hips (10 subjects) without previous surgery. The patients were studied in eight groups at scheduled intervals of 1 to 48 months. There were 10 hips in each group. The measurement of bone uptake in the healthy untreated control group indicated that the uptake ratio in the proximal femur was physiologically higher in the metaphyseal area than in the diaphyseal area and the uptake ratio in the acetabulum appeared to be much higher than that of the proximal femur. In the patient group, the uptake ratio around the femoral stem area and the acetabular cup area showed a statistically significant decrease between 1 and 3 months after surgery and changed little after 3 months. Comparing the result of the patient group with that of the healthy untreated control group, the uptake ratio decreased much faster in the hydroxyapatite-coated metaphyseal zone than in the noncoated diaphyseal zone of the femoral stem area. In the acetabular cup area, the uptake ratio decreased fast, as in the hydroxyapatite-coated metaphyseal zone of the femoral stem area. Based on these clinical results, a quantitative bone scan may be a helpful diagnostic procedure for evaluating postoperative progress when used in conjunction with clinical symptoms and radiologic examinations.

Adult↗
PubMed2002

High-pressure pulsatile lavage irrigation of fresh intraarticular fractures: effectiveness at removing particulate matter from bone.

OBJECTIVE: To determine the effectiveness of high-pressure pulsatile lavage (HPL) versus bulb syringe (BS) irrigation in removing particulate matter from metaphyseal cancellous bone. DESIGN: Four grams of particulate graphite were placed in twenty distal femoral intraarticular osteotomies performed on New Zealand rabbit hind limbs. Two groups of ten specimens were then irrigated using either HPL or BS irrigation. A representative coronal section from each specimen was then prepared for histologic evaluation using 400x light microscopy. The number and distribution of graphite particles-present as small (less than 20 micrometers), medium (20 to 50 micrometers), and large (greater than 50 micrometers) aggregates-were then recorded. RESULTS: The mean maximum perpendicular distance of graphite aggregates of all sizes from the osteotomy site was 12.4 millimeters (+/-SD 2.5) in the HPL group and 12.5 millimeters (+/-SD 2.0) in the BS group (p > 0.5). The mean number of aggregates within four 400x fields (1.08 millimeters) of the osteotomy site was 21.9 (+/-SD 22.0) in the HPL group and 21.8 (+/-SD 27.5) in the BS group (p > 0.5). The mean total number of aggregates in the area surveyed was 129.4 (+/-SD 79.6) in the HPL group and 137.5 (+/-SD 113.6) in the BS group (p > 0.5). Separate analyses controlling for aggregate size of the specimens also revealed no significant differences between HPL and BS irrigation. CONCLUSION: HPL and BS irrigation appear equally effective in removing particulate matter from metaphyseal cancellous bone in an intraarticular fracture model. Furthermore, HPL does not appear to drive particulate matter farther into metaphyseal cancellous bone than BS irrigation.

Animals↗