Objective To investigate the effect of homograft of marrow mesenchymal stem cells (MSCs) seeded onto poly-L-lactic acid (PLLA)/gelatin on repair of articular cartilage defects. Methods The MSCs derived from36 Qingzilan rabbits, aging 4 to 6 months and weighed 2.5-3.5 kg were cultured in vitroand seeded onto PLLA/gelatin. The MSCs/ PLLA/gelatin composite was cultured and transplanted into full thickness defects on intercondylar fossa. Thirty-six healthy Qingzilan rabbits were made models of cartilage defects in the intercondylar fossa. These rabbits were divided into 3 groups according to the repair materials with 12 in each group: group A, MSCs and PLLA/gelatin complex(MSCs/ PLLA/gelatin); group B, only PLLA/gelatin; and group C, nothing. At 4,8 and 12 weeks after operation, the gross, histological and immunohistochemical observations were made, and grading scales were evaluated. Results At 12 weeks after transplantation, defect was repaired and the structures of the cartilage surface and normal cartilage was in integrity. The defects in group A were repaired by the hylinelike tissue and defects in groups B and C were repaired by the fibrous tissues. Immunohistochemical staining showed that cells in the zones of repaired tissues were larger in size, arranged columnedly, riched in collagen Ⅱ matrix and integrated satisfactorily with native adjacent cartilages and subchondral bones in group A at 12 weeks postoperatively. In gross score, group A(2.75±0.89) was significantly better than group B (4.88±1.25) and group C (7.38±1.18) 12 weeks afteroperation, showing significant differences (P＜0.05); in histological score, group A (3.88±1.36) was better than group B (8.38±1.06) and group C (13.13±1.96), and group B was better than group C, showing significant differences (P＜0.05). Conclusion Transplantation of mesenchymal stem cells seeded onto PLLA/gelatin is a promising way for the treatment of cartilage defects.
Objective To observe the clinical effects of neurovascular island flap from the same finger for repairing pulp defect. Methods From November 2003 to February 2005, 32 pulp defects in 30 cases were covered with neurovascular island flap from the same finger.There were 25 males and 5 females. The age ranged from 18 to 56 years. The operation was performedafter debridement and 2-8 days antibiotics therapy. The defect area ranged from 1.5 cm×1.2 cm to 3.5 cm×2.1 cm. The flap was harvested on the dorsal part ofthe finger ularly or radially. The distal end of the flap should be more than 5mm away from the nail base to avoid nail injury. The ventral and dorsal cut should not exceed the middle line respectively. The flap size ranged from 2.0 cm×1.5 cm to4.0 cm×2.5 cm. The donor site was covered with flap of subdermal vascular plexus from the medial side of the upper arm. Results All 32 transferred flaps survived after operation. There was no vascular crisis. Twentyfive cases were followed up from 2 to 8 months. The flaps had good appearance and texture and blood circulation. Two-point discrimination was 7-10 mm. The function of finger motion was returned to normal. Conclusion Transfer of neurovascular island flap from the same finger offered a sensational skin flap for reconstruction of pulp defect. The technique was simple, andthe clinical result was satisfactory. It is an ideal method for reconstruction of thumb or finger pulp defects.
Objective To evaluate the clinical result of using osseointegratedimplants to retain removable orbital prostheses in repairing orbital defects. Methods Two patients with orbital defects caused by orbitaltumor were treated. Each of them got 4 implants. After average 6 months, we performed the secondary operation. After 7 weeks, we took impressions to make the implant-retained prostheses. The magnetic attachment was adopted. The prostheses were made of polysiloxane material(Factor II,Lakeside,Ariz). Results Both of the patients got the successful facial prostheses and were followed up 2 and 8 years respectively. All the implants were integrated well. There were no apparent inflammatory reactions in the soft tissue around percutaneous implants. The patients were satisfied with the facial appearance. Conclusion Implant-retained orbital prostheses are safe and effective in repairing orbital defects.
Objective To study the effect of direct bone morphogenetic protein 2 (BMP-2) gene therapy mediated by adenovirus on repairing bone defect. Methods The radial defect models were made on 60 rabbits, which were evenly divided into 4 groups randomly. The 4 groups were treated with different materials: group A, adenovirus carrying BMP-2 gene (AdBMP-2) plus bovine cancellous bone (BCB); group B, reconstructed BMP-2 plus BCB; group C, AdLacz plus BCB; and group D, only BCB scaffolds. The X-ray, histological examination, biomechanics analysis, and immunohistochemical staining were made 4, 8, and 12 weeks after the operation. Results Group A gained better effect in the volume of new bones, the anti-bending intensity of the healing bone, and the expression of BMP-2 than those of group B. The defect in group A was healed. No new bones were observed in group C and group D. Conclusion Direct BMP-2 gene therapy is easy to perform and has veryb osteoinduction ability. It is a good method to repair segmental bone defects.