Farnsworth K D, White N A, Robertson J
Marion duPont Scott Equine Medical Center and the Department of Pathology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Leesburg, VA, USA.
Vet Surg. 2001 Mar-Apr;30(2):126-31. doi: 10.1053/jvet.2001.21392.
To determine the effect of intra-articular gentamicin-impregnated polymethylmethacrylate (PMMA) beads inserted in the equine tarsocrural joint on the synovial fluid, synovial lining, and cartilage, and to determine the peak and sustainable gentamicin concentrations in synovial fluid and plasma.
Pharmacokinetic, cytologic, and histologic study of the effect of gentamicin-impregnated PMMA on normal equine tarsocrural joints.
Five healthy adult horses.
Gentamicin-impregnated PMMA bead strands (3 strands each of 40 beads, with each strand containing 100 mg gentamicin) were surgically inserted into one radiographically normal tarsocrural joint in 5 horses. Each horse had both joints flushed with 1 L of lactated Ringer's solution before bead administration. Synovial fluid total protein concentration, white blood cell (WBC) count, gentamicin concentration, synovial histology, cartilage integrity, and cartilage glycosaminoglycan (GAG) concentrations were determined.
Gentamicin concentration (mean +/- SEM peak concentration, 27.9 +/- 2.27 microg/mL) occurred in the first 24 hours and remained above 2 microg/mL for 9 days. Gentamicin concentrations in control joints and the plasma remained below detectable levels. The synovial fluid WBC count for treated joints was increased compared with control joints for 72 hours, but was similar at day 6. The synovial protein concentration in gentamicin-treated joints remained increased for 21 days. Synovium in treated joints had diffuse synovitis, whereas control joints had less fibrovascular proliferation. Superficial cartilage erosion was present in all treated joints. There was no difference in the GAG content of treated and control joint cartilage.
Short-term implantation of gentamicin (300 mg)-impregnated PMMA beads can provide therapeutic levels of gentamicin (>2 microg/mL) in the normal tarsocrural joint for 9 days; however, gentamicin-impregnated PMMA beads induce synovitis and superficial cartilage erosion.
Temporary intra-articular administration of antibiotic-impregnated PMMA may be an effective way to treat septic joints that require constant high concentrations of antibiotics.
确定将关节内庆大霉素浸渍的聚甲基丙烯酸甲酯（PMMA）珠粒植入马跗关节对滑液、滑膜衬里和软骨的影响，并确定滑液和血浆中庆大霉素的峰值和持续浓度。
对庆大霉素浸渍的PMMA对正常马跗关节影响的药代动力学、细胞学和组织学研究。
5匹健康成年马。
将庆大霉素浸渍的PMMA珠链（3条，每条40颗珠子，每条链含100mg庆大霉素）通过手术植入5匹马的一个X线检查正常的跗关节。在给予珠子前，每匹马的两个关节均用1L乳酸林格氏液冲洗。测定滑液总蛋白浓度、白细胞（WBC）计数、庆大霉素浓度、滑膜组织学、软骨完整性和软骨糖胺聚糖（GAG）浓度。
庆大霉素浓度（平均±SEM峰值浓度，27.9±2.27μg/mL）在最初24小时出现，并在9天内保持在2μg/mL以上。对照关节和血浆中的庆大霉素浓度保持在可检测水平以下。与对照关节相比，治疗关节的滑液WBC计数在72小时内增加，但在第6天时相似。庆大霉素治疗关节的滑液蛋白浓度在21天内持续升高。治疗关节的滑膜有弥漫性滑膜炎，而对照关节的纤维血管增生较少。所有治疗关节均出现浅表软骨侵蚀。治疗关节和对照关节软骨的GAG含量无差异。
短期植入庆大霉素（300mg）浸渍的PMMA珠粒可在正常跗关节中提供9天的治疗水平庆大霉素（>2μg/mL）；然而，庆大霉素浸渍的PMMA珠粒会诱发滑膜炎和浅表软骨侵蚀。
临时关节内给予抗生素浸渍的PMMA可能是治疗需要持续高浓度抗生素的化脓性关节的有效方法。
