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Journal of Orthopaedic Surgery and... Feb 2024Artificial tendons may be an effective alternative to autologous and allogenic tendon grafts for repairing critically sized tendon defects. The goal of this study was to...
BACKGROUND
Artificial tendons may be an effective alternative to autologous and allogenic tendon grafts for repairing critically sized tendon defects. The goal of this study was to quantify the in vivo hindlimb biomechanics (ground contact pressure and sagittal-plane motion) during hopping gait of rabbits having a critically sized tendon defect of the tibialis cranialis and either with or without repair using an artificial tendon.
METHODS
In five rabbits, the tibialis cranialis tendon of the left hindlimb was surgically replaced with a polyester, silicone-coated artificial tendon (PET-SI); five operated control rabbits underwent complete surgical excision of the biological tibialis cranialis tendon in the left hindlimb with no replacement (TE).
RESULTS
At 8 weeks post-surgery, peak vertical ground contact force in the left hindlimb was statistically significantly less compared to baseline for the TE group (p = 0.0215). Statistical parametric mapping (SPM) analysis showed that, compared to baseline, the knee was significantly more extended during stance at 2 weeks post-surgery and during the swing phase of stride at 2 and 8 weeks post-surgery for the TE group (p < 0.05). Also, the ankle was significantly more plantarflexed during swing at 2 and 8 weeks postoperative for the TE group (p < 0.05). In contrast, there were no significant differences in the SPM analysis among timepoints in the PET-SI group for the knee or ankle.
CONCLUSIONS
Our findings suggest that the artificial tibialis cranialis tendon effectively replaced the biomechanical function of the native tendon. Future studies should investigate (1) effects of artificial tendons on other (e.g., neuromuscular) tissues and systems and (2) biomechanical outcomes when there is a delay between tendon injury and artificial tendon implantation.
Topics: Animals; Rabbits; Silicones; Polyesters; Tendons; Ankle; Tendon Injuries; Biomechanical Phenomena
PubMed: 38303012
DOI: 10.1186/s13018-024-04581-7 -
Current Molecular Medicine 2017An alternative treatment for growth hormone deficiency based on hGH-DNA administration, followed by electro gene transfer, was investigated by injecting the plasmid into...
BACKGROUND
An alternative treatment for growth hormone deficiency based on hGH-DNA administration, followed by electro gene transfer, was investigated by injecting the plasmid into surgically exposed or non-exposed quadriceps or tibialis muscle of immunodeficient "little" mice.
METHODS
An optimization of electrotransfer conditions via a new combination of high/low voltage pulses is presented. After 3 days, serum hGH was determined and in a 28-day assay, the relative growth parameters were compared.
RESULTS
Both groups exhibited similar results: 5.0 ± 2.2 (SD) and 3.5 ± 0.9 ng hGH/ml (P>0.05; n=7) for the exposed quadriceps and non-exposed tibialis treatments, respectively. The final body weight increases were 16.1% for the quadriceps and 18.9% for the tibialis group. The tail and nose-to-tail length increases were 4.5% and 7.1% for the quadriceps and 4.8 and 4.6% for the tibialis group. The right and left femur length increases, obtained from radiographic measurements, were 16.9% and 12.7% for the quadriceps and 19.4% and 12.3% for the tibialis, respectively. A non-significant difference between exposed quadriceps and non-exposed tibialis treatments (P=0.48) was confirmed via a completely integrated statistical analysis. Circulating mIGF-1 levels were 126 ± 47, 106 ± 93 (P>0.05) and 38 ± 15 ng/ml for the quadriceps, tibialis and saline treatments, respectively.
CONCLUSION
These results show that hGH-DNA administration into non-exposed tibialis muscle followed by the new HV/LV electrotransfer protocol was an equally efficient, less traumatic treatment, much more suitable for pre-clinical testing than administration into exposed quadriceps.
Topics: Animals; DNA; Gene Transfer Techniques; Genetic Therapy; Growth Hormone; Humans; Insulin-Like Growth Factor I; Mice; Plasmids; Quadriceps Muscle
PubMed: 28730965
DOI: 10.2174/1566524017666170721152119 -
Molecules (Basel, Switzerland) Oct 2020Previous non-viral gene therapy was directed towards two animal models of dwarfism: Immunodeficient (lit/scid) and immunocompetent (lit/lit) dwarf mice. The former,...
Previous non-viral gene therapy was directed towards two animal models of dwarfism: Immunodeficient (lit/scid) and immunocompetent (lit/lit) dwarf mice. The former, based on hGH DNA administration into muscle, performed better, while the latter, a homologous model based on mGH DNA, was less efficient, though recommended as useful for pre-clinical assays. We have now improved the growth parameters aiming at a complete recovery of the lit/lit phenotype. Electrotransfer was based on three pulses of 375 V/cm of 25 ms each, after mGH-DNA administration into two sites of each non-exposed tibialis cranialis muscle. A 36-day bioassay, performed using 60-day old lit/lit mice, provided the highest GH circulatory levels we have ever obtained for GH non-viral gene therapy: 14.7 ± 3.7 ng mGH/mL. These levels, at the end of the experiment, were 8.5 ± 2.3 ng/mL, i.e., significantly higher than those of the positive control (4.5 ± 1.5 ng/mL). The catch-up growth reached 40.9% for body weight, 38.2% for body length and 82.6%-76.9% for femur length. The catch-up in terms of the mIGF-1 levels remained low, increasing from the previous value of 5.9% to the actual 8.5%. Although a complete phenotypic recovery was not obtained, it should be possible starting with much younger animals and/or increasing the number of injection sites.
Topics: Animals; Electroporation; Gene Transfer Techniques; Genetic Therapy; Growth Hormone; Mice; Muscle, Skeletal; Plasmids
PubMed: 33142961
DOI: 10.3390/molecules25215034 -
BioRxiv : the Preprint Server For... May 2024The purpose of this study was to investigate the factors associated with outcomes of attaching artificial tendons to bone using suture anchors for replacement of...
OBJECTIVE
The purpose of this study was to investigate the factors associated with outcomes of attaching artificial tendons to bone using suture anchors for replacement of biological tendons in rabbits.
STUDY DESIGN
Metal suture anchors with braided composite sutures of varying sizes (USP #1, #2, or #5) were used to secure artificial tendons replacing both the Achilles and tibialis cranialis tendons in 12 New Zealand White rabbits. Artificial tendons were implanted either at the time of (immediate replacement, n=8), or four weeks after (delayed replacement, n=4) resection of the biological tendon. Hindlimb radiographs of the rabbits were obtained immediately after surgery and approximately every other week until the study endpoint (16 weeks post-surgery).
RESULTS
All suture anchors used for the tibialis cranialis artificial tendons remained secure and did not fail during the study. The suture linkage between the Achilles artificial tendon and anchor failed in 9 of 12 rabbits. In all cases, the mode of failure was suture breakage distant from the knot. Based on radiographic analysis, the mean estimated failure timepoint was 5.3±2.3 weeks post-surgery, with a range of 2-10 weeks. Analysis of variance (ANOVA) tests revealed no significant effect of tendon implantation timing or suture size on either the timing or frequency of suture anchor failure.
CONCLUSION
Based on the mode of failure, suture mechanical properties, and suture anchor design, we suspect that the cause of failure was wear of the suture against the edges of the eyelet in the suture anchor post, which reduced the suture strength below in vivo loads. Suture anchor designs differed for the tibialis cranialis and did not fail during the period of study. Future studies are needed to optimize suture anchor mechanical performance under different loading conditions and suture anchor design features.
PubMed: 38746085
DOI: 10.1101/2024.04.29.591695 -
BMC Musculoskeletal Disorders Jan 2008Skeletal muscles are composed of heterogeneous collections of muscle fiber types, the arrangement of which contributes to a variety of functional capabilities in many... (Comparative Study)
Comparative Study
Dystrophin deficiency in canine X-linked muscular dystrophy in Japan (CXMDJ) alters myosin heavy chain expression profiles in the diaphragm more markedly than in the tibialis cranialis muscle.
BACKGROUND
Skeletal muscles are composed of heterogeneous collections of muscle fiber types, the arrangement of which contributes to a variety of functional capabilities in many muscle types. Furthermore, skeletal muscles can adapt individual myofibers under various circumstances, such as disease and exercise, by changing fiber types. This study was performed to examine the influence of dystrophin deficiency on fiber type composition of skeletal muscles in canine X-linked muscular dystrophy in Japan (CXMDJ), a large animal model for Duchenne muscular dystrophy.
METHODS
We used tibialis cranialis (TC) muscles and diaphragms of normal dogs and those with CXMDJ at various ages from 1 month to 3 years old. For classification of fiber types, muscle sections were immunostained with antibodies against fast, slow, or developmental myosin heavy chain (MHC), and the number and size of these fibers were analyzed. In addition, MHC isoforms were detected by gel electrophoresis.
RESULTS
In comparison with TC muscles of CXMDJ, the number of fibers expressing slow MHC increased markedly and the number of fibers expressing fast MHC decreased with growth in the affected diaphragm. In populations of muscle fibers expressing fast and/or slow MHC(s) but not developmental MHC of CXMDJ muscles, slow MHC fibers were predominant in number and showed selective enlargement. Especially, in CXMDJ diaphragms, the proportions of slow MHC fibers were significantly larger in populations of myofibers with non-expression of developmental MHC. Analyses of MHC isoforms also indicated a marked increase of type I and decrease of type IIA isoforms in the affected diaphragm at ages over 6 months. In addition, expression of developmental (embryonic and/or neonatal) MHC decreased in the CXMDJ diaphragm in adults, in contrast to continuous high-level expression in affected TC muscle.
CONCLUSION
The CXMDJ diaphragm showed marked changes in fiber type composition unlike TC muscles, suggesting that the affected diaphragm may be effectively adapted toward dystrophic stress by switching to predominantly slow fibers. Furthermore, the MHC expression profile in the CXMDJ diaphragm was markedly different from that in mdx mice, indicating that the dystrophic dog is a more appropriate model than a murine one, to investigate the mechanisms of respiratory failure in DMD.
Topics: Animals; Diaphragm; Disease Models, Animal; Dogs; Dystrophin; Fluorescent Antibody Technique, Direct; Muscle, Skeletal; Muscular Dystrophy, Animal; Muscular Dystrophy, Duchenne; Myosin Heavy Chains
PubMed: 18182116
DOI: 10.1186/1471-2474-9-1 -
American Journal of Veterinary Research Jul 1984Tendons of insertion of the equine tibialis cranialis muscle and peroneus tertius muscle (PT) were dissected grossly. Precise areas of tendon attachment and fiber...
Tendons of insertion of the equine tibialis cranialis muscle and peroneus tertius muscle (PT) were dissected grossly. Precise areas of tendon attachment and fiber arrangements within the tendons were described for the dorsal and medial tendons of the tibialis cranialis, and for the superficial lateral, deep lateral, dorsal, and medial tendons of the PT. Direct attachment of the dorsal and medial tendons of the PT into the periosteum of the central and 3rd tarsal bones and the 3rd metatarsal bone indicates that the PT may be involved in the pathogenesis of hock lamenesses.
Topics: Animals; Horses; Muscle, Skeletal; Tarsus, Animal
PubMed: 24049901
DOI: No ID Found -
Journal of Anatomy Oct 1988The percentages of Type I muscle fibres were measured systematically in ATPase-stained, transverse cryostat sections of whole tibialis cranialis muscles from 8 young,...
The percentages of Type I muscle fibres were measured systematically in ATPase-stained, transverse cryostat sections of whole tibialis cranialis muscles from 8 young, adult beagles. The distance of the section from the origin of the muscle does not significantly affect the mean percentage. There are no identifiable differences in mean percentages between right and left muscles. Differences in mean percentages between individuals are significant when sexes are combined (P less than 0.01) and within sexes (males: P less than 0.01; females: P less than 0.05). Within sections, the percentage tends to be lowest at the superficial (craniolateral) border and to vary less from site to site deeper within the muscle. Fibre cross sectional areas were measured systematically in the same sections of the right muscle from 3 males and 3 females. Mean areas for each section were greater for Type II than for Type I fibres. Mean areas for each fibre-type varied moderately and non-systematically between the sample sites within sections. A needle biopsy taken from deep within this muscle should provide a more consistent and reliable estimate of fibre-type proportion in the whole muscle than a superficial specimen. Proportions are not affected by the distance of the sample site from the muscle origin, and left or right muscles are suitable for sequential samples.
Topics: Animals; Dogs; Female; Male; Muscles; Tibia
PubMed: 3253248
DOI: No ID Found -
Journal of Anatomy Nov 2022Morphological study of the neuromuscular junction (NMJ), a specialised peripheral synapse formed between a lower motor neuron and skeletal muscle fibre, has...
Morphological study of the neuromuscular junction (NMJ), a specialised peripheral synapse formed between a lower motor neuron and skeletal muscle fibre, has significantly contributed to the understanding of synaptic biology and neuromuscular disease pathogenesis. Rodent NMJs are readily accessible, and research into conditions such as amyotrophic lateral sclerosis (ALS), Charcot-Marie-Tooth disease (CMT), and spinal muscular atrophy (SMA) has relied heavily on experimental work in these small mammals. However, given that nerve length dependency is an important feature of many peripheral neuropathies, these rodent models have clear shortcomings; large animal models might be preferable, but their size presents novel anatomical challenges. Overcoming these constraints to study the NMJ morphology of large mammalian distal limb muscles is of prime importance to increase cross-species translational neuromuscular research potential, particularly in the study of long motor units. In the past, NMJ phenotype analysis of large muscle bodies within the equine distal pelvic limb, such as the tibialis cranialis, or within muscles of high fibrous content, such as the soleus, has posed a distinct experimental hurdle. We optimised a technique for NMJ location and dissection from equine pelvic limb muscles. Using a quantification method validated in smaller species, we demonstrate their morphology and show that equine NMJs can be reliably dissected, stained and analysed. We reveal that the NMJs within the equine soleus have distinctly different morphologies when compared to the extensor digitorum longus and tibialis cranialis muscles. Overall, we demonstrate that equine distal pelvic limb muscles can be regionally dissected, with samples whole-mounted and their innervation patterns visualised. These methods will allow the localisation and analysis of neuromuscular junctions within the muscle bodies of large mammals to identify neuroanatomical and neuropathological features.
Topics: Animals; Coloring Agents; Horses; Mammals; Motor Neurons; Muscle Fibers, Skeletal; Muscle, Skeletal; Neuromuscular Junction; Peripheral Nervous System Diseases
PubMed: 36087283
DOI: 10.1111/joa.13747 -
Journal of Anatomy Jun 2022Tree sloths rely on their limb flexors for bodyweight support and joint stability during suspensory locomotion and posture. This study aims to describe the myology of...
Tree sloths rely on their limb flexors for bodyweight support and joint stability during suspensory locomotion and posture. This study aims to describe the myology of three-toed sloths and identify limb muscle traits that indicate modification for suspensorial habit. The pelvic limbs of the brown-throated three-toed sloth (Bradypus variegatus) were dissected, muscle belly mass was recorded, and the structural arrangements of the muscles were documented and compared with the available myological accounts for sloths. Overall, the limb musculature is simplified by containing muscles with generally long and parallel fascicles. A number of specific and informative muscle traits are additionally observed in the pelvic limb of B. variegatus: well-developed hip flexors and hip extensors each displaying several fused bellies; massive knee flexors; two heads of the m. adductor longus and m. gracilis; robust digital flexors and flexor tendons; m. tibialis cranialis muscle complex originating from the tibia and fibula and containing a modified m. extensor digitorum I longus; appreciable muscle mass devoted to ankle flexion and hindfoot supination; only m. extensor digitorum brevis acts to extend the digits. Collectively, the findings for tree sloths emphasize muscle mass and organization for suspensory support namely by the hip flexors, knee flexors, and limb adductors, for which the latter two groups may stabilize suspensory postures by exerting appreciable medially-directed force on the substrate. Specializations in the distal limb are also apparent for sustained purchase of the substrate by forceful digital flexion coupled with strong ankle flexion and supination of the hind feet, which is permitted by the reorganization of several digital extensors. Moreover, the reduction or loss of other digital flexor and ab-adductor muscles marks a dramatic simplification of the intrinsic foot musculature in B. variegatus, the extent to which varies across extant species of two- and three-toed tree sloths and likely is related to substrate preference/use.
Topics: Animals; Hindlimb; Locomotion; Muscle, Skeletal; Posture; Sloths
PubMed: 35037260
DOI: 10.1111/joa.13626 -
Annals of Anatomy = Anatomischer... Apr 2005The hindlimbs of the Malayan sun bear (Helarctos malayanus), the polar bear (Ursus maritimus), the brown bear (Ursus arctos) and the giant panda (Ailuropoda melanoleuca)...
The hindlimbs of the Malayan sun bear (Helarctos malayanus), the polar bear (Ursus maritimus), the brown bear (Ursus arctos) and the giant panda (Ailuropoda melanoleuca) have been anatomically and osteometrically studied. The Musculus tibialis cranialis of the Malayan sun bear and the giant panda possessed a well-developed rich fleshy portion until the distal end of the tibia. In the polar bear and the brown bear, however, the fleshy portion of the M. tibialis cranialis was not developed until the distal end of the tibia. The tendon of the M. tibialis cranialis inserting on the proximal end of the Ossa metatarsalia was shorter in the Malayan sun bear and the giant panda than in the polar bear and the brown bear. In the Malayan sun bear and the giant panda, moreover, the M. popliteus was attached more distally to the tibia than in the polar bear and the brown bear. The stable dorsiflexion and supination of the foot and the efficient pronation of the crus are important for skillful tree climbing. The present study suggests that the Malayan sun bear and the giant panda have hindlimbs especially adapted to tree climbing by the well-developed fleshy portion of the M. tibialis cranialis reaching the distal end of the tibia, its short tendon, and the M. popliteus inserting near the distal end of the tibia.
Topics: Adaptation, Physiological; Animals; Hindlimb; Motor Activity; Tibia; Ursidae
PubMed: 15900701
DOI: 10.1016/j.aanat.2004.10.001