Effect of microfracture combined with biomimetic hydrogel scaffold on rotator cuff tendon-to-bone healing in rabbits
10.7507/1002-1892.202001029
- Author:
Chenglong HUANG
1
Author Information
1. Department of Orthopedics, Clinical Medical School, Affiliated Shanghai No.10 People's Hospital, Nanjing Medical University
- Publication Type:Journal Article
- Keywords:
hydrogel;
microfracture;
rabbit;
Rotator cuff tear;
tendon-to-bone healing
- From:
Chinese Journal of Reparative and Reconstructive Surgery
2020;34(9):1177-1183
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To assess the effect of microfracture and biomimetic hydrogel scaffold on tendon-to-bone healing in a rabbit rotator cuff tear model. Methods: Gelatin and methacrylic anhydride were used to synthesize gelatin methacryloyl (GelMA). Then the GelMA were treated with ultraviolet rays and vacuum freeze-drying method to obtain a biomimetic hydrogel scaffold. The morphology of the scaffold was observed by gross observation and scanning electron microscope. Degradation of the scaffold was determined at different time points. Twenty-four adult New Zealand rabbits, weighting 2.8-3.5 kg and male or female, were surgically created the bilateral acute rotator cuff tear models. One shoulder was treated with microfractures on the footprint and transosseous suture (control group, n=24). The other shoulder was treated with the same way, except for putting the scaffold on the footprint before transosseous suture (experimental group, n=24). The general conditions of rabbits were observed postoperatively. Tendon-to-bone healing was evaluated by gross observation, Micro-CT, HE staining, and bio-mechanical testing at 4 and 8 weeks after operation. Results: The scaffold was white and has a porous structure with pore size of 31.7-89.9 μm, which degraded slowly in PBS solution. The degradation rate was about 95% at 18 days. All the rabbits survived to the completion of the experiment. Micro-CT showed that there was no obvious defect and re-tear at the tendon-to-bone interface in both groups. No difference was found in bone mineral density (BMD), tissue mineral density (TMD), and bone volume/total volume (BV/TV) between the two groups at 4 and 8 weeks postoperatively ( P>0.05). HE staining showed that the fibrous scar tissue was the main component at the tendon-to-bone interface in the control group at 4 and 8 weeks postoperatively; the disorderly arranged mineralized cartilage and fibrocartilage formation were observed at the tendon-to-bone interface in the experimental group at 4 weeks, and the orderly arranged cartilage formation was observed at 8 weeks. Besides, the tendon maturation scores of the experimental group were significantly higher than those of the control group at 4 and 8 weeks ( P<0.05). There was no significant difference in the ultimate load to failure and stiffness between the two groups at 4 weeks ( P>0.05); the ultimate load to failure at 8 weeks was significantly higher in the experiment group than in the control group ( t=4.162, P=0.009), and no significant difference was found in stiffness between the two groups at 8 weeks ( t=2.286, P=0.071). Conclusion: Compared with microfracture alone, microfracture combined with biomimetic hydrogel scaffold can enhance tendon-to-bone healing and improve the ultimate load to failure in rabbits.
