Bone marrow mesenchymal stem cells in a hyaluronan scaffold for treatment of an osteochondral defect in a rabbit model

The purpose of this study was to evaluate the efficiency of using mesenchymal stem cells (MSC) in a hyaluronan scaffold for repair of an osteochondral defect in rabbit knee. Bone marrow was harvested from the posterior iliac crest in 11 New Zealand White rabbits. MSC were isolated and cultured in autologous serum for 28 days and transferred to a hyaluronan scaffold 24 h prior to implantation. A 4 mm diameter and 1.5 mm deep defect was created in the medial femoral condyle of both knees and the scaffold with MSC was implanted in one knee while an empty scaffold was implanted in the contra-lateral knee. After 24 weeks the rabbits were killed and histological sections were subjected to semiquantitative and quantitative evaluation by observers blinded regarding treatment modality. High degree of filling was obtained, but there was no statistically significant difference between the two treatments. However, there was a tendency for a better quality of repair in the MSC treated knees. No hypertrophy was observed by either method. MSC in a hyaluronan scaffold may be a promising treatment approach, but further studies are needed to determine the best combination of scaffold and cells.     

Superior results with continuous passive motion compared to active motion after periosteal transplantation A retrospective study of human patella cartilage defect treatment

Fifty-seven consecutive patients (33 men and 24 women), with a mean age of 32 years (range 16–53 years), who suffered from an isolated full-thickness cartilage defect of the patella and disabling knee pain of long duration, were treated by autologous periosteal transplantation to the cartilage defect. The first 38 consecutive patients (group A) were postoperatively treated with continuous passive motion (CPM), and the next 19 consecutive patients (group B) were treated with active motion for the first 5 days postoperatively. In both groups, the initial regimens were followed by active motion, slowly progressive strength training, and slowly progressive weight bearing. In group A, after a mean follow-up of 51 months (range 33–92 months), 29 patients (76%) were graded as excellent or good, 7 patients (19%) were graded as fair, and 2 patients (5%) were graded as poor. In group B, after a mean follow-up of 21 months (range 14–28 months), 10 patients (53%) were graded as excellent or good, 6 patients (32%) were graded as fair, and 3 patients (15%) were graded as poor. Altogether, nine of the fair or poor cases (50%) were diagnosed with chondromalacia of the patella. Our results, after performing autologous periosteal transplantation in patients with full-thickness cartilage defects of the patella and disabling knee pain, are good if CPM is used postoperatively. The clinical results using active motion postoperatively are not acceptable, especially not in patients with chondromalacia of the patella. Received: 24 November 1998 Accepted: 30 January 1999