Objective To evaluate the effect of weight-bearing time on micro-fracture therapy for small sized osteochondral lesion of the talus (OLT) by comparing early weight-bearing and postponed weight-bearing. Methods Between March 2010 and September 2011, 43 patients with small sized OLT (lt; 2 cm2) scheduled for arthroscopic micro-fracture therapy were randomly divided into early weight-bearing group (n=22) and postponed weight-bearing group (n=21). There was no significant difference in gender, age, body mass index, disease duration, disease cause, preoperative visual analogue scale (VAS) score, and preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score between 2 groups (P gt; 0.05). All patients of 2 groups received micro-fracture treatment under arthroscopy. Full weight bearing began under the protection of “8” figure shaped splint at immediately after operation in early weight-bearing group, and weight bearing began at 6 weeks after operation in postponed weight-bearing group. Results The size of cartilage injury was (1.24 ± 0.35) cm2 in early weight-bearing group and was (1.25 ± 0.42) cm2 in postponed weight-bearing group by arthroscopy measurement, showing no significant difference between 2 groups (t=0.09, P=0.93); and there was no significant difference in cartilage injury grading between 2 groups (Z= — 1.45, P=0.15). The follow-up time was 12-18 months (mean, 14.5 months) in 2 groups. VAS and AOFAS scores of each group at each time point after operation were all significantly improved when compared with preoperative scores (P lt; 0.05), but no significant difference was found between 2 groups at 3, 6, and 12 months after operation (P gt; 0.05). The time of returning to work in early weight-bearing group [(6.35 ± 1.93) months] was significantly shorter than that in postponed weight-bearing group [(8.75 ± 1.48) months] (t= — 4.10, P=0.00). Conclusion For patients with small sized OLT, early weight-bearing and postponed weight-bearing after micro-fracture therapy under arthroscopy have similar short-term results. But patients undergoing early weight-bearing can earlier return to work than patients undergoing postponed weight-bearing.
ObjectiveTo investigate the effects of micro-fracture and insul in-l ike growth factor 1 (IGF-1) in treatment of articular cartilage defect in rabbits. MethodsTwenty-four New Zealand white rabbits (aged, 4-6 months; weighing, 2.5-3.5 kg) were randomly divided into 4 groups (n=6):micro-fractures and recombinant human IGF-1 (rhIGF-1) treatment group (group A), micro-fracture control group (group B), rhIGF-1 treatment control group (group C), and blank control group (group D). Full thickness articular cartilage defects of 8 mm×6 mm in size were created in the bilateral femoral condyles of all rabbits. The micro-fracture surgery was performed in groups A and B. The 0.1 mL rhIGF-1 (0.01 μg/μL) was injected into the knee cavity in groups A and C at 3 times a week for 4 weeks after operation, while 0.1 mL sal ine was injected in groups B and D at the same time points. At 4, 12, and 24 weeks, the gross, histological, and immunohistochemical observations were performed, and histological score also was processed according to Wakitani's score criteria. The collagen contents in the repair tissues and normal patellofemoral cartilage were detected by the improved hydroxyproline (HPR) method at 24 weeks. Electron microscope was used to observe repair tissues of groups A and B at 24 weeks. Results All animals were survival at the end of experiment. At 24 weeks after operation, defect was repaired with time, and the repair tissue was similar to normal cartilage in group A; the repair tissue was even without boundary with normal cartilage in group B; and the repair tissue was uneven with clear boundary with normal cartilage in groups C and D. Histological staining showed that the repair tissues had no difference with normal cartilage in group A; many oval chondrocytes-l ike cells and l ight-colored matrix were seen in the repair tissues of group B; only a few small spindle-shaped fibroblasts were seen in groups C and D. Moreover, histological scores of group A were significantly better than those of groups B, C, and D (P<0.05) at 4, 12, and 24 weeks. Electron microscope observation showed that a large number of lacuna were seen on the surface of repair tissue in group A, and chondrocytes contained glycogen granules were located in lacunae, and were surrounded with the collagen fibers, which was better than that in group B. Collagen content of the repair tissue in group A was significantly higher than that in groups B, C, and D (P<0.05), but it was significantly lower than that of normal cartilage (P<0.05). Conclusion Combination of micro-fracture and rhIGF-1 for the treatment of full thickness articular cartilage defects could promote the repair of defects by hyaline cartilage.