Is the repair of articular cartilage lesion by costal chondrocyte transplantation donor age-dependent? An experimental study in rabbits.

The repair of chondral injuries is a very important problem and a subject of many experimental and clinical studies. Different techniques to induce articular cartilage repair are under investigation. In the present study, we have investigated whether the repair of articular cartilage folowing costal chondrocyte transplantation is donor age-dependent. Transplantation of costal chondrocytes from 4- and 24-week old donors, with artificially induced femoral cartilage lesion, was performed on fourteen 20-week-old New Zealand White male rabbits. In the control group, the lesion was left without chondrocyte transplantation. The evaluation of the cartilage repair was performed after 12 weeks of transplantation. We analyzed the macroscopic and histological appearance of the newly formed tissue. Immunohistochemistry was also performed using monoclonal antibodies against rabbit collagen type II. The newly formed tissue had a hyaline-like appearance in most of the lesions after chondrocyte transplantation. Positive immunohistochemical reaction for collagen II was also observed in both groups with transplanted chondrocytes. Cartilage from adult donors required longer isolation time and induced slightly poorer repair. However, hyaline-like cartilage was observed in most specimens from this group, in contrast to the control group, where fibrous connective tissue filled the lesions. Rabbit costal chondrocytes seem to be a potentially useful material for inducing articular cartilage repair and, even more important, they can also be derived from adult, sexually mature animals.

Long-term outcome of early treatment of developmental hip dysplasia using an abduction splint.

Background. Treatment of congenital hip dysplasia, when implemented in the first weeks of life, gives a good outcome. Very few publications, however, have addressed the anatomical remodeling of the affected hip. In this study, we evaluate the anatomical outcome of the treatment applied. Material and methods. We examined 89 children diagnosed with congenital hip dysplasia in the first three months of life and then treated with an abduction device, for a total of 148 hips. The time of follow-up varied from 8 to 13 years. All these children were given a clinical examination according to McKay, along with Severin X-ray classification. Results. Before treatment was implemented, the patients had been diagnosed as types IIc (56 hips, 37.8%), IId (34 hips, 22.9%), III (40 hips, 27.1%), and IV (18 hips, 12.2%). In one hip final assessment showed signs of aseptic necrosis of the proximal femur. 147 hips showed total remodeling, and in the Severin X-ray classification scheme were evaluated as type I. Conclusions. Severin X-ray clasification is easy to implement and in our material corresponds with the clinical evaluation according to McKay. Early implementation of treatment with an abduction device is worthwhile and gives a satisfactory outcome.

Rabbit articular cartilage defects treated with cultured costal chondrocytes (preliminary report).

An attempt to repair articular cartilage defects by costal chondrocytes transplantation was made. A full-thickness defect in the rabbit's femoral patellar groove was artificially made. Cultured costal cartilage chondrocytes were then transplanted into the defects and covered with periosteal flaps. Empty defects were used as the control group. Animals were divided into two groups (five rabbits each). They were examined after four and twelve weeks from the day of transplantation, respectively. The reparative tissue was evaluated by macroscopic and histological examinations. The reparative tissues in defects with transplanted chondrocytes had an hyaline-like cartilage appearance and were firmly attached to the surrounding normal cartilage. No trace of newly formed bone was detected. The reparative tissues found in defects that were left empty had a fibrous character. They were loosely connected to the surrounding cartilage and were more compliant than tissues from transplanted defects. Considering these initial findings, the ease of surgical procedures during the harvesting of the costal cartilage and few interventions into the joint make the costal cartilage a promising source of chondrocytes for transplantation. However, this needs to be confirmed on a larger scale over a longer period of time.

Clinical value of neonatal screening for congenital dysplasia of the hip.

Background. The problem of clinical value of neonatal screening for congenital dysplasia of the hip was described in this paper.
Material and methods. We have analyzed clinical and sonographicall documentation of a random group of 4950 children from years 1991, 1995 and 1999 treated in Outpatient Clinic for Screening of Congenital Dislocation of the Hip in Children Hospital of Medical University in Bialystok, to asses clinical value of our screening program.
Results. Congenital dysplasia (type IIb - IV according to Graf classification) was found in 3.27%, 3.3% and 2.97 of all children scanned in years 1991, 1995 and 1999 respectively. We have observed increasing number of children scanned before the end of fourth week of life (36.97%, 67.82%, 75.76% in years 1991, 1995 and 1999 respectively). The number of patients with late diagnosis of congenital hip dysplasia (after twelfth week of life) were decreasing with every year (59.26%, 16.51%, 12.24% in years 1991, 1995 and 1999 respectively). Also the number of subluxated and dislocated hips (type III and IV according to Graf classification) was decreasing with years (9, 0 and 1in years 1991, 1995 and 1999 respectively).
22 out of 108 hips with dysplasia could be included into the high risk group in year 1991 and 19 out of 109, and 22 out of 98 in years 1995 and 1999 respectively.
Conclusions. Results of our analysis allowed us to conclude that neonatal screening for congenital hip dysplasia in all newborns is very useful in preventing and treating hip subluxation and dislocation. Limiting this screening only to the children from the high risk group caries the danger of significant increase in late diagnosis of hip dysplasia and thus following dislocation of the hip.