Local Soft Tissue Compression Enhances Fracture Healing in a Rabbit Fibula

Regional activation of cellular repair systems, including local application of hyaluronic acid, is a promising direction for the sanogenesis of muscle injuries. Purpose: to identify the sanogenetic and pharmacological effects of local application of hyaluronic acid in experimental soft tissue compression trauma. Compression injury was simulated by mechanical compression of the right pelvic limb of a rat at the level of the lower leg for 7 hours with a pressure force of 10-12 kg/cm2. Further, the animals were divided into 2 groups: 3 hours after decompression, animals in the main group were injected with 3.5% hyaluronic acid (the drug «Hyalift 3.5») by fan-pricking with a sterile disposable syringe at 5-6 points to a depth of 0.5-0.8 cm in a volume of up to 0.1 ml at each point; rats in the control group were given a similar method and an equivalent volume of 0.9% sodium chloride solution. The level of myoglobin in the blood, microcirculation, histomorphological and immuno- histochemical characteristics of tissues in the compression area were studied. A comprehensive analysis of the results of the study allowed us to establish that early local administration of 3.5% hyaluronic acid to the area of compression damage of soft tissues (3 hours after decompression) has a muscle-protecting effect, activates the repair system of damaged skeletal muscles. It is concluded that the sanogenetic effect of hyaluronic acid is mediated by the mecha- nisms of its pharmacological action: activation of angiogenesis, improvement of in situ efficiency of microcirculation and metabolism, reduction of the severity of primary and secondary necrosis and about traumatic disorders, activation of regeneration of damaged muscle fibers with the formation of muscle tissue. Hyaluronic acid is an active stimulant of reparative processes in the perspective of pharmacotherapy and may be a promising component in the local correction of extensive traumatic injuries.

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A Modified Footplate for the Kerrison Rongeur

Journal of Medical Devices ◽

10.1115/1.4000594 ◽

2010 ◽

Vol 4 (1) ◽

Author(s):

Alim P. Mitha ◽

Mohamed S. Ahmad ◽

Sarah J. Cohen ◽

Janet S. Lieberman ◽

Martin R. Udengaard ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Soft Tissue ◽

Spinal Surgery ◽

Significant Issue ◽

Bone Removal ◽

Cutting Surface ◽

Cerebrospinal Fluid Leaks ◽

Dural Tears ◽

Csf Leaks ◽

Tissue Compression

Use of the Kerrison rongeur for bone removal in spinal surgery is associated with dural tears and cerebrospinal fluid (CSF) leaks. We report a modification of the Kerrison rongeur footplate designed to reduce the risk of dural tears. A novel footplate was designed by incorporating the following parameters: (1) tapering the footplate to deflect soft tissue downward during positioning of the rongeur underneath the bone, and (2) making the footplate longer and wider than the cutting element to prevent soft tissue from entering into the cutting surface. Stereolithography models of the modified footplate were made and tested in a cadaver. A stainless steel modified footplate was then incorporated into an existing Kerrison rongeur as a working prototype, and tested in 20 laminectomy cases to clinically validate its design. The modified footplate prevented soft tissue from entering the cutting surface of the Kerrison rongeur in the manner intended by its design. No dural tears or CSF leaks were encountered in any instance. Potential soft tissue compression caused by an increase in footplate dimensions was not a significant issue in the rongeur size tested. This modification, however, might not be practical in rongeurs larger than 3 mm. The risk of dural tears and cerebrospinal fluid leaks in spinal surgery may be reduced by this footplate modification of the Kerrison rongeur. Soft tissue compression may limit the incorporation of this modification to rongeurs of 3 mm or smaller. The promising results warrant further tests with a wider range of sizes.

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Magnetic Resonance Imaging of Postoperative Fracture Healing Process without Metal Artifact: A Preliminary Report of a Novel Animal Model

BioMed Research International ◽

10.1155/2016/1429892 ◽

2016 ◽

Vol 2016 ◽

pp. 1-4 ◽

Cited By ~ 2

Author(s):

Zhe Jin ◽

Yuheng Guan ◽

Guibo Yu ◽

Yu Sun

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Soft Tissue ◽

Fracture Healing ◽

Healing Process ◽

Intramedullary Fixation ◽

Metal Artifact ◽

Resonance Imaging ◽

X Ray

Background. Early radiological diagnosis and continual monitoring are of ultimate importance for timely treatment of delayed union, nonunion, and infection after bone fracture surgery. Although magnetic resonance imaging (MRI) could provide superior detailed images compared with X-ray and computed tomography (CT) without ionizing radiation, metal implants used for fracture fixation lead to abundant artifacts on MRI and thus prohibit accurate interpretation. The authors develop a novel intramedullary fixation model of rat femoral fracture using polyetheretherketone (PEEK) threaded rods and investigate its feasibility for in vivo MRI monitoring of the fracture healing process without artifact.Methods. Femoral fractures of 3 adult male Sprague-Dawley rats were fixed with intramedullary PEEK threaded rods. X-ray and MRI examinations were performed at day 7 postoperatively. Radiological images were analyzed for the existence of artifact interruption and postoperative changes in bone and peripheral soft tissue.Results. Postoperative plain film revealed no loss of reduction. MRI images illustrated the whole length of femur and peripheral tissue without artifact interruption, and the cortical bone, implanted PEEK rod, and soft tissue were clearly illustrated.Conclusion. This preliminary study introduced a novel rat model for in vivo MRI monitoring of the fracture healing process without metal artifact, by using intramedullary fixation of femur with PEEK threaded rod.

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