Intra-articular injection of a nutritive mixture solution protects articular cartilage from osteoarthritic progression induced by anterior cruciate ligament transection in mature rabbits: a randomized controlled trial

Abstract

Osteoarthritis (OA) is a degenerative disease that disrupts the collagenous matrix of articular cartilage and is difficult to cure because articular cartilage is a nonvascular tissue. Treatment of OA has targeted macromolecular substitutes for cartilage components, such as hyaluronic acid or genetically engineered materials. However, the goal of the present study was to examine whether intra-articular injection of the elementary nutrients restores the matrix of arthritic knee joints in mature animals. A nutritive mixture solution (NMS) was composed of elementary nutrients such as glucose or dextrose, amino acids and ascorbic acid. It was administered five times (at weeks 6, 8, 10, 13 and 16) into the unilateral anterior cruciate ligament transected knee joints of mature New Zealand White rabbits, and the effect of NMS injection was compared with that of normal saline. OA progression was histopathologically evaluated by haematoxylin and eosin staining, by the Mankin grading method and by scanning electron microscopy at week 19. NMS injection decreased progressive erosion of articular cartilage overall compared with injection of normal saline (P < 0.01), and nms joints exhibited no differences relative to normal cartilage that had not undergone transection of the anterior cruciate ligament, as assessed using the mankin grading method. Haematoxylin and eosin staining and scanning electron microscopy findings also indicated that nms injection, in contrast to normal saline injection, restored the cartilage matrix, which is known to be composed of a collagen and proteoglycan network. thus, nms injection is a potent treatment that significantly retards oa progression, which in turn prevents progressive destruction of joints and functional loss in mature animals.

Figure 1

Schematic diagram of the experimental protocol. The Normal group includes right knee joints from the mature rabbits, which had not undergone any surgery or treatment (n = 7). In the ACLT+NMS group, joints had undergone anterior cruciate ligament transection (ACLT) surgery followed by injections of nutritive mixture solution (NMS; n = 7). In the ACLT+NS group, joints had undergone ATLC surgery followed by normal saline (NS) injections (n = 11). The intra-articular injection volume was 0.5 ml (NMS or NS), and injections were given for 13 consecutive weeks starting on the week 6 after surgery and with 2-week or 3-week intervals. All of the rabbits were dissected at week 19, and histopathological examinations (such as haematoxylin and eosin staining, Mankin grading method and scanning electron microscopy) were performed in all three groups.

Figure 2

Representative photomicrographs of articular cartilage of the medial tibial plateau. These photomicrographs were taken at 19 weeks after anterior cruciate ligament transection surgery, the stain used is haematoxylin and eosin, and the magnificantion is ×100. (a) Normal group. (b) Nutritive mixture solution (NMS) group. (c) Normal saline (NS) group.

Figure 3

Scanning electron micrographs of articular cartilage surface of the medial tibial plateau. These micrographs were taken at 19 weeks after anterior cruciate ligament transection surgery and the magnification is ×6,000 (scale bar is 10 μm). (a) Normal group. (b) Nutritive mixture solution (NMS) group. (c) Normal saline (NS) group.