bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinematics of the cervical spine: Effects of multiple total laminectomy and facet wiring
Authors: Goel Vijay K. , Clark Charles R. , Harris Kurt G. , Schulte Kary R. 
Published: February 2005

AbstractThe effect of multiple‐level total laminectomies followed by stabilization on the load‐deformation behavior of the cervical spine is described. Fresh human ligamentous cervical spines (C2‐T2) were potted and clinically relevant load types applied via a loading frame attached to the C‐2 vertebra of the specimen. A set of three infrared light‐emitting diodes (LEDs) were attached rigidly to each of five vertebrae (C3‐7) to record their spatial locations after each load step application, using a Selspot II system. The specimen was tested again after total laminectomy performed on C5. The supraspinous, interspinous, and flavum ligaments between the C4‐5 and C5‐6 motion segments were cut; thereafter, the vertebral arch was removed. The specimen testing was resumed after inducing injury at C‐6 in a similar fashion. The specimen was stabilized, using a facet wiring construct, across the C4‐7 segment before testing for the final time. The load‐deformation data of the injured and stabilized tests were normalized with regard to the corresponding results of the intact test. In flexion‐extension mode, an increase in motion of about 10% after laminectomies was observed. Facet wiring was found to be an effective technique to stabilize injured cervical spines (≈80% reduction in motion, compared with intact spines, was observed).
Treatment of denervation/disuse osteoporosis in the rat with a capacitively coupled electrical signal: Effects on bone formation and bone resorption
Authors: Brighton Carl T. , Tadduni Gregory T. , Goll Stephen R. , Pollack Solomon R. 
Published: February 2005

AbstractUtilizing a sciatic neurectomy model of disuse osteoporosis, the effects on rates of bone formation and bone resorption were examined when a capacitively coupled electrical signal was applied to the denervated tibia in the rat. It was found that a low‐voltage, symmetrical sine wave, 60‐kHz, capacitively coupled signal had no significant effect on the amount of bone resorption occurring in denervated right tibiae in rats previously labeled with [3H]tetracycline. This was true whether the signal was applied while osteoporosis was developing (prevention of osteoporosis) or after it had been established (treatment of osteoporosis). If a similar capacitively coupled signal was applied to rats in which osteoporosis was well established, and the rats were labeled with [3H]tetracycline daily during a 12‐day treatment period, it was found that there was statistically significant enhancement of the amount of new bone formation (increased [3H]tetracycline incorporation) in the tibiae that received the signal as compared with that of the controls. These results indicate that prevention or amelioration of disuse osteoporosis that occurs with a capacitively coupled electrical signal is due not to a change in the rate of bone resorption, but to an increase in the rate of bone formation.
Effect of direct current on cultured growth cartilage cells in vitro
Authors: Okihana Hiroyuki , Shimomura Yutaka 
Published: February 2005

AbstractCultured growth cartilage cells of young rabbits were stimulated by three levels(10, l and 0.l μA) of constant direct current (DC). The effect of DC was examined by measuring the activities of proteoglycan synthesis (uptake of [35S]sodium sulfate and toluidine blue staining) and DNA synthesis (uptake of [3H]thymidine). DC increased syntheses of both proteoglycans and DNA when l μA calculated curren densiy of l μA/cm2 was applied for 3 days. A longer stimulation resulted in a larger difference between stimulated and unstimulted cells. Ten‐microampere stimulation devitalized the cells, while 0.l μA had no effect on cell activities.
Transplacental effects of vitamin A on fetal bones in mice—follow‐up studies on postnatal recovery
Authors: Atkin Isaac , Cohen Irena , Schwartz Z. , Castiglione G. , Ornoy Asher 
Published: February 2005

AbstractPregnant mice were injected with pharmacological doses of vitamin A during days 11–19 of gestation with the purpose of studying the long bones of offspring up to the age of 1 week. Tibiae were collected for routine light microscopic examination and tranmission electron microscopic examination. In addition, biochemical studies were conducted to determine the calcium, phosphorus, and magnesium content as well as the hydroxyproline and protein content of the bones. Treatment with vitamin A resulted in reduced weight and length of the long bones, as well as the presence of excessive calcification throughout the hypertrophic zone of the cartilaginous epiphyses. Matrix vesicles, many of them containing hydroxyapatite crystals, were observed and found to be distributed within the cartilaginous epiphyses in a similar pattern as in untreated control mice offspring, but mineral crystals were also observed unassociated with the matrix vesicles. The calcium, phosphate, magnesium, and hydroxyproline content was reduced in the vitamin A offspring. However, the percentage of these minerals expressed per dry weight bone was higher than in controls, verifying the morphological findings that although vitamin A inhibits bone growth, it enhances calcification in the growth plate.
Postural control in single‐limb stance
Authors: Tropp Hans , Odenrick Per 
Published: February 2005

AbstractPostural control in single‐limb stance has previously been shown to be impaired among soccer players with functional instability (FI) of the ankle joint. The aim of the present study was to further study the role of the ankle in postural control. A dynamic method was used involving optoelectronic movement recordings of body segments and force‐plate recordings of the reaction ground force. Surface electromyography was recorded for the peroneus longus muscle. Thirty physically active men were selected. Fifteen of them had FI of the ankle chosen for recording. The results show that different patterns exist for maintaining equilibrium in single‐limb stance. The ankle has a central role for postural corrections. The position of center of pressure is highly correlated to the position of the ankle and peroneal muscle activity. When the body was in disequilibrium, corrections were made at the hip. It is proposed that a change from an inverted pendulum model to a multisegmental chain model takes place when adjustments at the ankle joint no longer suffice to maintain postural control. The men with FI showed impaired postural control associated with increased upper segmental corrections.
Standardized biomechanical measurement for varus‐valgus stiffness and rotation in normal knees
Authors: Bryant J. T. , Cooke T. D. V. 
Published: February 2005

AbstractSeventeen female and 24 male subjects had varus and valgus and apparent rotations measured using a standardized mechanical testing device that cyclically applied a 20‐Nm moment in each direction. Five parameters‐apparent varus rotation, apparent valgus rotation, apparent overall rotation, varus stiffness, and valgus stiffness showed intersubject variations approaching 40%. Right‐left variations in the same subject averaged 12%, with no significant right‐left differences overall. Female knees rotated 66% more than male knees and were 35% less stiff. The ratio of apparent valgus rotation to apparent varus rotation averaged 0.775, and the ratio of valgus stiffness to varus stiffness averaged 1.23 for all knees. Stiffness and rotation parameters were highly correlated for both genders in the valgus phase of testing. Results suggest that although magnitudes of measured parameters vary considerably from subject, common relationships between parameters from the same normal knee exist.
Geometry of the first metatarsophalangeal joint
Authors: Yoshioka Yuki , Siu David W. , Cooke T. Derek V. , Bryant J. T. , Wyss Urs 
Published: February 2005

AbstractThis study aimed to define the articular geometry of the metatarsophalangeal (MTP) joint of the great toe. Embedded in resin blocks, five pairs of cadaveric first MTP joints (all from men) were sequentially cut in the sagittal plane with a milling machine, removing 0.5 mm of bone in each cut. The photographed cartilaginous outline of each cut was digitized against reference markers, which enabled a computer system to superimpose each outline in three dimensions. The intersesamoidal ridge was found to be parallel to the lateral shaft. The peak of the ridge was just lateral to the midline of the MT head. The articular outline, through the ridge of each sample, was circular; however, other surface contours were noncircular. The undulating plantar aspect of the MTP head formed by the intersesamoidal ridge and related grooves was found to have symmetric relationships to the sesamoid bones and a consistent orientation to the shaft. The rounded distal dorsal aspect of the MTP head showed consistent differences to the concavity formed by the phalangeal base. The sample size is too small for the sizing of prostheses but it is adequate to study the geometry of the MTP joint. More data are needed for the accurate replication of a resurfacing prosthesis and understanding of joint kinematics.
Geometry of the humeroulnar joint
Authors: Shiba Ryoichi , Sorbie Charles , Siu David W. , Bryant J. Timothy , Cooke T. Derek V. , Wevers Hendrik W. 
Published: February 2005

AbstractClinical results with elbow prostheses have been disappointing. A detailed knowledge of elbow joint geometry and mechanics is necessary to improve prosthetic design. In this study, the humeroulnar articulation of four human cadaver elbows was examined using surface analytic methods. In this article, the location of the transverse axis of elbow flexion‐extension is suggested in relation to well‐defined landmarks, the medial and lateral epicondyles, and subsequently to the line connecting their most lateral points—the transepicondylar line. The geometry of the structures responsible for the carrying angle is discussed, as is the extent of cartilage‐covered bearing areas of the lower humerus and upper ulna. Implications pertaining to prosthetic design and surgical technique resulting from this study are discussed.
An electron microscopic study of the changes observed in osteocytes under ischemic conditions
Authors: Usui Yasuo , Kawai Kazuo , Hirohata Kazushi 
Published: February 2005

AbstractThe purpose of this study was to observe the process of ischemia in osteocytes using light and electron microscopy and to compare the changes in these ischemic osteocytes with those in other types of osteocytes (i.e., degenerative osteocytes in physiological states, steroid‐induced lipid‐accumulating osteocytes) that have been previously reported. Five female Japanese white rabbits were used in this study. Osteochondral chips were taken from one side of the femoral condyle, covered with Millipore filters, and then inserted into the other side of the knee joint. These tissues were examined after 12 h and after 2, 5, 8, and 14 days of ischemia under both light and electron microscopy. Under light microscopy, osteocytes and lacunae were classified into four types: normal osteocyte, pyknotic osteocyte, pale osteocyte, and empty osteocyte lacuna. The number of each type of osteocyte (or lacuna) in a settled area was counted. The ratio of normal osteocytes decreased significantly (p < 0.001) after the second day of ischemia. Pyknotic osteocytes increased at 12 h (p < 0.01) and 2 days (p < 0.001) of ischemia. On the fifth day of ischemia, the percentage of pale osteocytes reached a peak. This was followed by a gradual increase in the number of empty lacunae. On the fourteenth day of ischemia, empty lacunac constituted >40% of the cell types. When viewed by electron microscopy, these necrotic osteocytes were similar to the degenerative osteocytes that have been observed in physiological states and apparently different from lipid‐accumulating osteocytes. The results suggested that there could be at least two types of necrotic processes in osteocytes that eventually lead to cell death.
Effects of indomethacin on bone ingrowth
Authors: Keller J. C. , Trancik T. M. , Young F. A. , Mary E. St. 
Published: February 2005

AbstractThe effects of indomethacin, a nonsteriodal antiinflammatory agent, on bone ingrowth were studied using a rabbit animal model and a porous cylindrical implant system. Bone ingrowth was found to be independent of pore size in the range tested (0.6–1.0 mm). In the control (placebo‐treated) group, there was a significant increase in bone ingrowth between the 2‐ and 8‐week groups of animals. However, in the indomethacin‐treated group, there was no increase in bone ingrowth with time.
Growth factor stimulation of adult articular cartilage
Authors: Osborn Keith D. , Trippel Stephen B. , Mankin Henry J. 
Published: February 2005

AbstractWe have examined the effect of peptide growth factors on DNA and proteoglycan synthesis by adult bovine articular cartilage in organ culture. The actions of somatomedin‐C/insulin‐like growth factor I (Sm‐C/IGF‐I), insulin, epidermal growth factor (EGF), and fibroblast growth factor (FGF) from bovine pituitary were investigated individually and in combination. FGF stimulated a 10‐fold increase in tritiated thymidine incorporation while other factors used individually did not influence mitotic activity. Used in concert, insulin with EGF and insulin with FGF acted synergistically in stimulating DNA synthesis 20‐fold and 40‐fold, respectively. All of these growth factors, acting individually, significantly enhanced radiosulfate incorporation. This stimulation was additive for Sm‐C/IGF‐I in combination with EGF or FGF, but not with insulin. These data indicate that adult bovine articular chondrocytes possess the capacity to augment both mitotic and differentiated cell functions in response to growth factors. The data further suggest that, with the exception of insulin and Sm‐C/IGF‐I, which appear to share a common mechanism of action, these factors produce their cellular effects via different receptor or postreceptor pathways.
Mechanical properties of primate vascularized vs. nonvascularized patellar tendon grafts; changes over time
Authors: Butler David L. , Grood Edward S. , Noyes Frank R. , Olmstead Marvin L. , Hohn R. Bruce , Arnoczky Steven P. , Siegel Mark G. 
Published: February 2005

AbstractMechanical properties of patellar tendon autografts used to replace the anterior cruciate ligament (ACL) in the cynomolgus monkey were measured at four time periods up to 1 year. The ACL was replaced in each knee with the medial half of the patellar tendon: as a vascularized graft (VG) on one side and as a nonvascularized or free graft (FG) on the other. Postoperative care consisted of 4 weeks of cast immobilization at 30° flexion followed by unrestricted activity in a large cage. Both grafts showed low stiffness and maximum force at 7 weeks (24% and 16% of ACL control values, respectively), increasing to 57% of control ACL stiffness and 39% of control maximum force by 1 year. Corresponding material properties, modulus and maximum stress, also increased over time, but at 1 year were only 34% and 26% of ACL values, respectively. The results indicate that retaining vascularity does not prevent significant reduction in graft properties that occur postoperatively, nor does it accelerate the return in strength and stiffness. Tissue stiffness, which returns earlier than maximum force and joint anteroposterior (AP) force displacement data, should be routinely reported in any healing study. Finally, in studies of this kind, the large variation in the results makes sampling only one or two animals from each time period unreliable.
Nonalcoholic carbonated beverage consumption and bone fractures among women former college athletes
Authors: Wyshak Grace , Frisch Rose E. , Albright Tenley E. , Albright Nile L. , Schiff Isaac , Witschi Jelia 
Published: February 2005

AbstractWe report on data relating to nonalcoholic carbonated beverage consumption and bone fractures in 5,398 college alumnae, 2,622 former college athletes and 2,776 nonathletes, who responded to a detailed mailed questionnaire. A statistically significant association between nonalcoholic carbonated beverage consumption and bone fractures was found only in the former athletes, not the nonathletes. Among the athletes, the age‐adjusted odds ratio (OR) for the association of drinkers (yes/no) with any fracture (yes/no) was 1.35,95% confidence limits (CL) (1.14, 1.59). The dose‐response relationship between the amount of carbonated beverages consumed daily and the number of bone fractures of the athletes was also statistically significant. Results of multiple logistic regression analysis, which included only alumnae ≥50 years of age and which controlled for current exercise and other potential confounding factors, were as follows:(a) for athletes, the OR for the association of drinking nonalcoholic carbonated beverages and a first bone fracture at or after age 40 was 2.28, 95% CL (1.36, 3.84); (b) for all alumnae, a low milk diet was a risk factor for first bone fractures at or after age 40, OR = 1.92, 95% CL (1.15, 3.16); (c) former college athletes had a significantly lower risk of first fractures at or after age 40 than did nonathletes; OR = 0.63, 95% CL (0.40, 0.99). The deleterious effect of nonalcoholic carbonated beverage consumption on the risk of bone fractures has not been reported, as far as we know. These results, if confirmed, may have important public health implications because of the 300% increase in carbonated beverage consumption combined with a decline in milk consumption in the U.S. over the last three decades.
Dynamic changes in the dimensions of the lumbar spinal canal: An experimental study in vitro
Authors: Schönström Nils , Lindahl Sven , Willén Jan , Hansson Tommy 
Published: February 2005

AbstractThe variation in the dimensions of the lumbar spinal canal under both flexion‐extension and axial compression‐distraction was studied using computerized tomography (CT) scans in human cadaver lumbar spine specimens. In 3‐mm‐thick CT slices through the disk at L3‐L4, the cross‐sectional area of the spinal canal was reduced by around 40 mm2, corresponding to a 16% reduction of the initial area when the lumbar spines were moved both from flexion to extension and from distraction to compression. A corresponding reduction in the midsagittal diameter of the canal of 2 mm was found. During these motions, the ligamentum flavum did not appear to be a significant factor for the dynamic changes affecting the dimensions of the canal. This held true even after the disk had been excised in order to produce a total collapse of the disk space.
Blood indices of muscle injury associated with eccentric muscle contractions
Authors: Fridén J. , Sfakianos P. N. , Hargens A. R. 
Published: February 2005

AbstractSerum muscle enzyme activities of eight healthy men (22–32 years old) were measured before and 48 h after separate bouts of repetitive concentric, eccentric, and isometric contractions of the lower leg anterior compartments. Serum creatine kinase and glutamic oxaloacetic acid transaminase levels were both elevated 2 days after the eccentric exercise regimen, exclusively (36 and 17%, respectively). Lactic dehydrogenase levels were not affected by any of the protocols. Delayed muscle soreness was exclusively reported from the eccentrically exercised limb. We suggest that the high tensions developed during eccentric exercise cause mechanical damage, possibly including sarcolemmal degeneration. Subsequently, muscle enzymes are released to the blood. We conclude that postexercise serum levels of some muscle enzymes, at the time of maximal soreness, are qualitative markers of muscle damage.
Electromyographic study of the anterior cruciate ligament–hamstrings synergy during isometric knee extension
Authors: Grabiner M. D. , Campbell K. R. , Hawthorne D. L. , Hawkins D. A. 
Published: February 2005

AbstractThe purpose of this investigation was to determine the role the hamstrings group may play in augmenting passive articular mechanisms during activity in which anterior drawer force may detrimentally affect the anterior cruciate ligament (ACL). Nine male subjects performed non‐weight‐bearing isometric knee extension at 10% increments of maximum voluntary contraction (MVC). Electromyographic (EMG) signals were detected and recorded from the vastus lateralis, vastus medialis oblique, vastus medialis longus, and the long head of the biceps femoris. The EMG signals were rectified and integrated over 1000 ms and normalized to subject‐specific values. The data were subjected to a repeated‐measures analysis of variance. The results demonstrated that expected significant increases in quadriceps excitation accompanied increases in knee extensor torque. Hamstrings excitation was not found to change significantly (total change = 3.4%). It was concluded that functionally adequate knees do not require posterior drawer force in excess of that provided passively by articular structures.
Limb lengthening by epiphyseal distraction in chondrodystrophic bone: An experimental study in the canine femur
Authors: Fjeld Terje O. , Steen Harald 
Published: February 2005

AbstractEpiphyseal distraction of the left distal femur was accomplished in 18 chondrodystrophic dogs (age 19–22 weeks). A distraction rate of 0.5 mm/day was applied by means of a unilateral device. Epiphysiolysis occurred after 4 to 9 days. Lengthening was continued for 3 weeks. The animals were killed at 3 (Group 1; n = 5), 19 (Group 2; n = 10), and 71 (Group 3; n = 3) weeks after the end of distraction to verify the magnitude of elongation at removal of the device (Group 1) and at the time of growth cessation (Groups 2 and 3), and to register possible permanent secondary joint changes (Group 3). The average lengthening of 1.2 cm (12.3%) at removal of the device was reduced to 0.7 cm (6.4%) at cessation of growth. The middiaphyseal diameter of the elongated femur was enlarged after the lengthening procedure in all animals. The average torsional strength of the elongated femur compared with the contralateral control was 83% in Group 1, 98% in Group 2, and 107% in Group 3. Degenerative changes were observed in the knee joints of three animals in each group. A two‐way analysis of variance was applied for all data sets to test differences between control and elongated bones and between time periods. The reduction in gained length by retardation of residual growth in the distal femur was significant (p < 0.05). The difference in external diameter between lengthened and control bones was significant in Groups 1 and 3 (p < 0.05). We conclude that early onset of bilateral lengthening by epiphyseal distraction in chondrodystrophic bone required in successive treatment of bone segments may result in significant loss of gained length due to reduction of residual growth. The observed degenerative changes in the knee joint are a sequela that calls into question the use of the method in the femur.