strontium-radioisotopes and Tibial-Fractures

The effects of femoral and sciatic nerve resection on fracture healing and innervation of the fracture callus were studied using a stable fracture model. In 34 rats the right tibia was subjected to a standardized closed fracture and stabilized with a modular intramedullary nail. In half of the animals, resection of 1 cm of the femoral and sciatic nerves was performed (nerve resection group), whereas the other animals had sham operations (sham group). To avoid unequal load-bearing between the two groups, all fractured hindlimbs were immobilized in a plaster of Paris cast. The trial was terminated after 5 weeks of fracture healing. Callus size was scored radiographically, and bone mineralization was measured by 85-strontium incorporation. Seven rats from each group had immunohistochemical examination for neural regeneration and ingrowth. Antisera for protein gene product 9.5, neurofilaments, neural growth associated protein 43/B-50, calcitonin gene related peptide, and substance P were used. The mechanical properties of the healing fractures were recorded in a three-point cantilever bending test. After 5 weeks, the normally innervated, fractured tibias had regained approximately 50% strength compared with the unfractured side, in comparison with only 20% in the animals that had nerve resection. Although the fracture calluses were mechanically weaker, they were significantly larger in the nerve resection group, indicating defects in tissue composition or organization rendered by the nerve injury. The mineralization rate, as measured by 85-strontium incorporation, was the same in the two groups. However, the nerve resection did not provide complete denervation but changed the innervation pattern of the healing fracture, as the density of sensory nerve fibers immunostaining for substance P and neurofilaments was less in the group with femoral and sciatic nerve resection. The results suggest that intact innervation is essential for normal fracture healing because nerve injury induced a large, but mechanically insufficient, fracture callus.

Topics: Animals; Biomechanical Phenomena; Bony Callus; Casts, Surgical; Femoral Nerve; Fracture Fixation, Intramedullary; Fracture Healing; Immunohistochemistry; Radiography; Rats; Rats, Wistar; Sciatic Nerve; Specific Pathogen-Free Organisms; Strontium Radioisotopes; Tibia; Tibial Fractures

Topics: Albumins; Animals; Capillary Permeability; Carbon Radioisotopes; Chromium Radioisotopes; Dogs; Indicator Dilution Techniques; Male; Minerals; Regional Blood Flow; Specific Gravity; Strontium Radioisotopes; Sucrose; Tibia; Tibial Fractures

Topics: Animals; Bone and Bones; Bone Plates; Dogs; Male; Methylmethacrylates; Necrosis; Osteotomy; Strontium Radioisotopes; Tibia; Tibial Fractures

The healing of a diaphyseal tibia fracture was followed in the rat. Callus formation, blood flow and Sr-85 uptake were assessed by a ratio comparison of the fractured to the contralateral side. No correlation was found between blood flow and Sr-85 deposition in the callus and the adjacent bone of the same extremity. It is concluded that the deposition of a radiopharmaceutical in bone is primarily related to the presence of calcifiable organic bone matrix and only secondarily to the bone formation rate and to variations in the local blood flow.

Topics: Animals; Femur; Fractures, Closed; Male; Radionuclide Imaging; Rats; Regional Blood Flow; Strontium Radioisotopes; Tibia; Tibial Fractures; Wound Healing

Activity levels of 99TC-labeled compounds, 18F, and 85Sr were obtained at 1, 3, and 5 hr. postinjection in normal and healing fractured bone and in soft-tissue rat specimens. Serial diagnostic bone images and blood and urine kinetics were obtained in patients with each of the TC-labeled compounds. Computer-processed images were used to evaluate in vivo kinetics. 99mTC pyrophosphate provides the best overall characteristics for bone imaging. Improved quality and bioassay procedures are required, however, before any one agent can be designated the radiopharmaceutical of choice for diagnostic bone imaging.

Topics: Animals; Diphosphates; Disease Models, Animal; Fluorine; Fractures, Bone; Humans; Isotope Labeling; Kinetics; Phosphates; Radioisotopes; Radionuclide Imaging; Rats; Strontium Radioisotopes; Technetium; Tibial Fractures; Wound Healing

The concentration of 99mTc-pyrophosphate was determined in the lower extremities of rabbits (normal, abacterial and bacterial affected soft tissues), in osteoarthritis of the hip joint (capsule and muscle) as well as in knee joint effusions. Compared with the 85Sr-concentration, reflecting the calcification capacity, concentrations of 99mTc-pyrophosphate in soft tissues were found to be lower 2 hours p.i., but were up to elevenfold higher 24 hours p.i. These findings should be due to a fixation of 99mTc-pyrophosphate in collagen containing tissues as in the soft tissue tumors (myosarcoma, synvialioma, breast cancer) presented. A mechanism of delayed equilibration could explain augmented uptake in lymph-edema, ascites and effusions in florid osteoarthritis of the knee joint. The possible dependence of 99mTc-pyrophosphate concentration in bone and soft tissue on collagenous contents is discussed.

Topics: Animals; Ascites; Bone and Bones; Breast Neoplasms; Diphosphates; Disease Models, Animal; Extremities; Freund's Adjuvant; Hip; Humans; Joint Diseases; Joint Prosthesis; Joints; Knee; Osteoarthritis; Phosphates; Rabbits; Rhabdomyosarcoma; Sarcoma, Synovial; Strontium; Strontium Radioisotopes; Technetium; Tibial Fractures; Time Factors; Tin

A total of 203 profile countings were performed on 68 fractures of the tibial shaft, which included 25 normally healing cases, 37 cases of delayed union, and six cases of non-union. The measurements were performed on the 1st and the 7th day after the injection of strontium. In 27 cases the fracture received 2-3 strontium injections with associated profile counting at different stages of the healing process. The cases of normally healing fractures and delayed union showed differences in the average strontium uptake. However, these differences were not distinct enough to enable classification of individual fractures into groups. In cases requiring bone grafting, the transplant was found to accelerate metabolism and increase the accretion of strontium at the site of the fracture. The investigation shows that the real value of strontium profile counting lies in its ability to give information about the osteogenetic activity of the bone, which is a necessary prerequisite for the healing of the fracture.

Topics: Bone Transplantation; Fractures, Ununited; Humans; Strontium Radioisotopes; Tibial Fractures; Time Factors; Wound Healing

Topics: Bone and Bones; Fractures, Ununited; Humans; Scintillation Counting; Strontium Radioisotopes; Technetium; Tibial Fractures

Measurement of 125I-labeled 4-iodoantipyrine (I-Ap) washout is a useful method to study changes in bone blood flow because it can demonstrate fine changes in flow, the tracer is not involved in tissue metabolism, and several measurements can be made in the same subject. In the tibiae of twenty-one adult dogs there was a significant (p smaller than 0.001) correlation between I-Ap washout and the deposition of 85Sr, suggesting that the uptake of 85Sr is related to blood flow. After fracture, blood flow at the fracture site reached a maximum on the tenth day and then progressively decreased, but was not back to control values at 112 days. In the proximal part of the diaphysis, away from the fracture site, flow reached a maximum at five to twenty-one days and then progressively decreased to normal.

Topics: Animals; Bony Callus; Calcification, Physiologic; Dogs; Mathematics; Minerals; Regional Blood Flow; Strontium; Strontium Radioisotopes; Tibia; Tibial Fractures; Time Factors; Wound Healing

Topics: Adult; Aged; Bone Plates; Calcium Sulfate; Female; Fracture Fixation; Humans; Injections, Intravenous; Male; Middle Aged; Radionuclide Imaging; Strontium Radioisotopes; Tibia; Tibial Fractures; Time Factors; Wound Healing

Topics: Animals; Biomechanical Phenomena; Body Weight; Bony Callus; Collagen; Hindlimb; Hydroxyproline; Male; Mice; Organ Size; Phenytoin; Stimulation, Chemical; Strontium Radioisotopes; Tibial Fractures; Time Factors; Wound Healing

Topics: Atrophy; Bone Development; Humans; Pseudarthrosis; Radiography; Strontium Radioisotopes; Tibia; Tibial Fractures