Hurtig M, Pearce S, Warren S, Kalra M, Miniaci A
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Ontario, Canada N1G 2W1.
Vet Surg. 2001 May-Jun;30(3):228-39. doi: 10.1053/jvet.2001.23348.
To investigate survival and function of autogenous heterotopic osteochondral grafts in a site where injuries are common.
Three osteochondral grafts were harvested arthroscopically from the femoropatellar joint and transplanted to the third carpal bone (C(3)). Nine months later, histologic, histomorphometric, and biochemical comparisons were made between the transplanted grafts in C(3) and tissue adjacent to the recipient site, the opposing radial carpal bone (C(r)), the donor site in the femoropatellar joint, and the sham-operated contralateral C(3).
One mixed-breed pony and 5 Standardbred horses aged 3 to 8 years old.
Using instruments modified for equine use, four 4.5-mm-diameter osteochondral grafts were harvested arthroscopically from the distal aspect of the lateral trochlea of the right femur and inserted into the radial facet of the right third carpal bone. The fourth graft was kept as a donor-site control sample. Three months later, regular exercise was started and at 6 months, repeat arthroscopy was conducted to evaluate healing. The horses were euthanatized 9 months after transplantation, and comparisons were made between the grafts, opposing radial carpal bone, and contralateral third carpal bone. The assessment criteria included paravital staining, a modified Mankin scoring system, and biochemical analyses for collagen type, total collagen content, and sulfated glycosaminoglycan concentration.
All horses were sound 21 days' postoperatively. At 6 months, all 18 grafts were intact but somewhat soft and opaque compared with surrounding carpal cartilage. Nine months' postoperatively, the bony portions of the grafts were well integrated with the recipient sites, but 6 grafts had histologic evidence of cartilage degeneration. From biochemical analysis of grafts, there was little or no new repair tissue invading the experimental sites, but sulfated glycosaminoglycan (proteoglycan) loss from the transplanted cartilage was marked.
Heterotopic transfer of osteochondral grafts from the distal aspect of the lateral femoral trochlea to the third carpal bone is feasible with minor modifications of human mosaic arthroplasty instruments. The bony portion of the osteochondral grafts was quickly remodeled to provide subchondral support to the transplanted articular cartilage. The loss of proteoglycan from the transplanted cartilage indicates that the grafts might have been injured during harvesting or insertion, or, more likely, did not remodel to meet the demands of a new biomechanical environment.
These findings suggest that arthroscopic resurfacing of focal osteoarticular defects will not be successful in the long term unless donor and recipient sites can be matched with respect to cartilage thickness, biochemical constituents, and physical properties. Mosaic arthroplasty may be indicated in selected cases in which no other options exist to create a confluent cartilage-covered surface.
研究自体异位骨软骨移植在常见损伤部位的存活及功能情况。
通过关节镜从股髌关节获取三块骨软骨移植物，并移植至第三腕骨（C(3)）。九个月后，对移植于C(3)的移植物与受体部位相邻组织、相对的桡侧腕骨（C(r)）、股髌关节的供体部位以及假手术对侧的C(3)进行组织学、组织形态计量学和生化比较。
一匹杂种小马和五匹3至8岁的标准赛马。
使用为马改良的器械，通过关节镜从右股骨外侧滑车远端获取四块直径4.5毫米的骨软骨移植物，并植入右第三腕骨的桡关节面。第四块移植物留作供体部位对照样本。三个月后开始常规运动，六个月时进行重复关节镜检查以评估愈合情况。移植九个月后对马匹实施安乐死，对移植物、相对的桡侧腕骨和对侧第三腕骨进行比较。评估标准包括活组织染色、改良的曼金评分系统以及对胶原类型、总胶原含量和硫酸化糖胺聚糖浓度的生化分析。
所有马匹术后21天状态良好。六个月时，所有18块移植物均完整，但与周围腕软骨相比略显柔软且不透明。术后九个月，移植物的骨部分与受体部位融合良好，但有6块移植物有软骨退变的组织学证据。对移植物的生化分析显示，几乎没有新的修复组织侵入实验部位，但移植软骨中的硫酸化糖胺聚糖（蛋白聚糖）损失明显。
对人类镶嵌式关节成形术器械稍作改良后，将骨软骨移植物从股骨外侧滑车远端异位转移至第三腕骨是可行的。骨软骨移植物的骨部分迅速重塑，为移植的关节软骨提供软骨下支持。移植软骨中蛋白聚糖的损失表明，移植物可能在获取或植入过程中受损，或者更有可能的是，未进行重塑以适应新的生物力学环境。
这些发现表明，除非供体和受体部位在软骨厚度、生化成分和物理特性方面能够匹配，否则关节镜下修复局灶性骨关节缺损在长期内不会成功。在没有其他选择来创建融合的软骨覆盖表面的特定病例中，可能需要进行镶嵌式关节成形术。
