Use of scintimetry to assess effects of exercise and polysulfated glycosaminoglycan on equine carpal joints with osteochondral defects.
Abstract: Combined blood pool and delayed images produced by use of 99mTc-methylene diphosphonate (99mTcMDP) were evaluated as an objective measurement of the response of equine joints with osteochondral defects to postoperative exercise and intra-articularly administered polysulfated glycosaminoglycan (PSGAG). Osteochondral defects (approx 2.4 x 0.9 cm) were induced arthroscopically in the dorsodistal radial carpal bones of 18 ponies. These ponies were randomized (while balancing for age [range 2 to 15; median, 5.0; mean, 5.1 years]) to 2 treatment groups. Nine ponies were assigned to be exercised, and 9 were stall-rested. Six ponies in each group were administered PSGAG (250 mg) in 1 joint (medicated) and lactated Ringer's solution (LRS) in the contralateral joint. The 3 remaining ponies in each group were administered LRS in both joints (nonmedicated). Medication was given at surgery, then weekly for 4 weeks. The exercise protocol (begun at postoperative day 6 and conducted twice daily) started with 30 minutes walking (approx 0.7 m/s), and, by postoperative month 3, the ponies were being walked for 15 minutes and trotted (approx 1.6 m/s) for 25 minutes. Simultaneous dorsal images of both carpi were made 2 to 3 minutes after IV administration of 99mTcMDP (blood pool image) and 90 to 120 minutes later (delayed image). Scintimetry, in counts per minute per pixel per millicurie, was done before, and at 1, 2, 4, 8, 10, 13, and 17 weeks after surgery, prior to euthanasia. Radionuclide uptake on blood pool images decreased faster than that on delayed images, in which uptake remained high for 17 weeks. This indicated that bone was metabolically active for at least 17 weeks after surgery. Exercise significantly (P < 0.05) decreased uptake on the blood pool images of medicated joints up to 1 month after surgery. Thus, exercise (in the presence of PSGAG) probably had a transient, beneficial effect on soft tissues of the joint. Exercise, without PSGAG, promoted increased bone remodeling, because the highest uptake on delayed images was observed in exercised, nonmedicated ponies up to 3 months after surgery. This was consistent with development of osteoarthritis in these ponies. Medication alone stimulated bone remodeling, and data indicated that an identical effect may take place in contralateral LRS-injected joints, because of systemic circulation of the drug. However, the combination of exercise and medication appeared to moderate the independent effects of each. The combination of exercise and medication in individual joints resulted in notably (P < 0.05) decreased bone remodeling.(ABSTRACT TRUNCATED AT 400 WORDS)
Publication Date: 1993-07-01 PubMed ID: 8368620
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- Journal Article
- Research Support
- Non-U.S. Gov't
- Research Support
- U.S. Gov't
- P.H.S.
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The study investigates the impact of exercise and a drug known as polysulfated glycosaminoglycan (PSGAG) on equine carpal joints with osteochondral defects, highlighting that exercise coupled with PSGAG treatment significantly reduced joint damage and promoted healthy bone remodeling.
Research Methodology
- Arthroscopic procedures were used to induce osteochondral defects in the dorsodistal radial carpal bones of 18 ponies.
- The ponies were divided into two groups, with half being exercised and the other half being stall-rested.
- In both groups, six ponies were given 250mg of PSGAG in one joint and lactated Ringer’s solution (LRS) in the other. The remaining ponies were administered LRS in both joints.
- The administering of medications, initiated during surgery, continued weekly for four weeks.
- The exercise regimen, which began on the sixth postoperative day, started with half an hour of walking. This progressed to 15 minutes of walking and 25 minutes of trotting by the third postoperative month.
Findings
- Scintimetry, or a form of imaging, was done at several points over 17 weeks, revealing continuing bone activity post-surgery, indicating resilient metabolic activity.
- Exercise notably reduced uptake in medicated joints a month after surgery, suggesting a beneficial, although temporary, effect of exercise in concert with PSGAG on joint soft tissues.
- Exercise without PSGAG led to increased bone remodeling, as shown by the highest uptake on delayed images in non-medicated, exercised ponies, indicating the development of osteoarthritis.
- PSGAG alone prompted bone remodeling, with findings indicating similar effects may occur in joints injected with the LRS due to the systemic circulation of the drug.
- The combined intervention of exercise and medication seemed to moderate the independent effects of each intervention. Combining exercise and medication in individual joints led to noticeable decreases in bone remodeling.
Conclusion
- The research demonstrates that the use of exercise in combination with PSGAG can significantly reduce bone damage and promote healthier bone remodeling in equines with carpal osteochondral defects.
Cite This Article
APA
Todhunter RJ, Altman NS, Kallfelz FA, Nersesian P, Lust G.
(1993).
Use of scintimetry to assess effects of exercise and polysulfated glycosaminoglycan on equine carpal joints with osteochondral defects.
Am J Vet Res, 54(7), 997-1006.
Publication
Researcher Affiliations
- James A. Baker Institute for Animal Health, College of Veterinary Medicine, Department of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853.
MeSH Terms
- Animals
- Carpal Bones
- Glycosaminoglycans / administration & dosage
- Glycosaminoglycans / therapeutic use
- Horses / physiology
- Injections, Intra-Articular
- Joints / diagnostic imaging
- Joints / physiopathology
- Joints / surgery
- Osteochondritis / diagnostic imaging
- Osteochondritis / physiopathology
- Osteochondritis / therapy
- Physical Conditioning, Animal
- Radionuclide Imaging
- Technetium Tc 99m Medronate
- Time Factors
Grant Funding
- AR-35664 / NIAMS NIH HHS
Citations
This article has been cited 2 times.- Uhlhorn H, Eksell P, Sandgren B, Carlsten J. Sclerosis of the third carpal bone. A prospective study of its significance in a group of young standardbred trotters. Acta Vet Scand 2000;41(1):51-61.
- White GW. Polysulfated glycosaminoglycan as a treatment for osteoarthritis in veterinary medicine: Summary of the pharmacological, laboratory, and clinical data. Open Vet J 2025 Sep;15(9):4007-4023.
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