Evaluation of biomarkers following autologous osteochondral transplantation in the equine stifle joint — An experimental study

Abstract

The purpose of this study was to evaluate changes in biomarker and synovial parameters following autologous osteochondral transplantation (AOT) in the equine stifle joint, to test the hypothesis whether synovial parameters would show significant differences at selected time points following the surgery (at days 3, 14, 60 and 180) compared to baseline level (at day 0). Surgical intervention was performed in both stifles of nine horses (n = 18). The joints were randomly assigned to operated and sham-operated groups. Grafts 8.5 mm in diameter were harvested from the femoropatellar (FP) joint under arthroscopic control and the medial femorotibial (MFT) joints had AOT using mosaicplasty (MP) instrumentation, while the sham FP and sham MFT joints underwent arthroscopy and miniarthrotomy without transplantation, respectively. Synovial fluid (SF) parameters were evaluated at days 4, 14, 60 and 180. Data were analysed by two-way repeated-measures analysis of variance (ANOVA), and P < 0.05 was considered significant. During the first 10-14 days after surgery, lameness of degree 2-3/5 [American Association of Equine Practitioners (AAEP) scores] was present, which disappeared after 60 days. Joints with transplantation showed significant increases in synovial white blood cell count (WBC), total protein (TP), substance P, C1,2C and CS846 epitope concentration at day 3 compared to baseline and shamoperated joints (P < 0.05). These parameters returned to the baseline values by two months after surgery and remained within normal levels at 6 months postoperatively.

Arthroscopic Management of Joint Problems in the Sport Horse

“…Arthroscopic mosaic arthroplasty or mosaicplasty is commonly used in human surgery to repair large chondral defects by harvesting osteochondral grafts from non-weight-bearing areas and transplanting them to the affected site. This approach has been experimentally evaluated in the equine radiocarpal, metacarpophalangeal and femoropatellar joints [28]. In one study, three osteochondral grafts were harvested arthroscopically from the femoropatellar joint and transplanted to the third carpal bone.…”

“…Nine months after the operation, the osteochondral grafts in the third carpal bone had less proteoglycans, leaving the cartilage softer and less resistant compared to the surrounding cartilage. Six of 18 grafts had histological evidence of cartilage degeneration and it was suggested that the discrepancy in cartilage thickness as well as chondrocyte phenotypic expression between the donor and recipient sites was a major limitation to obtaining functional osteochondral integration [28].…”

“…Most donor sites were reconstructed with cancellous bone and covered with fibrocartilage, and 3 of 60 showed mild surface fibrillation. The discrepancy in articular surface geometry between the donor and recipient sites results in articular surface incongruity which in many cases is the major limitation to the success of this procedure [28].…”