A very large part of the population is affecting with degenerative spine disease, among which lumbar segment being most common. The most promising of them seems to be the cellular therapy based on a percutaneous transplantation of autologous chondrocytes into the intervertebral disc previously operated on with the purpose of stimulating production by the matrix, increasing the population of chondrocytes as well as restoring the disturbed catabolism-anabolism balance. The chondrocytes transplantation was carried out by commonly used approach in vertebroplasty procedure.
A research group led by Zbigniew Czernicki, Mossakowski Medical Research Centre has investigated human population consisting of 50 patients operated on for one-level discopathy who underwent implantation of autologous chondrocytes into the operated space.
The study group included 50 patients, 26 women and 24 men, aged 18 to 40, who underwent single-level L4-L5 or L5-S1 discectomy. The acute radicular syndrome within the lumbar segment has been revealed by clinical examination of the patients before the operation. Biopsy material for histological evaluation of the operated intervertebral disc and for cellular culture was sampled from fragments of the removed nuclei pulposi. The results in two cases were: Light microscope pictures of the starting material prior to the implantation, used for culture and the herniated disc material after the implantation Hematoxylin and eosin staining. Confocal microscope pictures of the starting material before implantation used for cellular culture and the herniated disc material after implantation showing chondrocytes and intercellular matrix components.
The aim of research was thus to structurally recreate the nucleus pulposus with all its functions as well as to restore balance to the distorted metabolic processes of the degenerated nucleus pulposus. The cells most commonly used in research were chondrocytes, mesenchymal cells and adipose cells. The researchers attempted to assess the effectiveness of autologous chondrocyte transplantation. The integrity of transplanted cells and their productive properties after the transplantation were examined in vivo and in vitro. Fifteen patients were implanted approximately 20 million immature allogenic chondrocytes which resulted in their good adaptation to the intracellular matrix. This study also shows the necessity to perform the implantation. The uniqueness of the study consists in the fact that patients in whom the implantation was performed had not been operated on earlier and the cells inserted into the nucleus pulposus were to complement the loss of cells in result of degenerative changes. Improvement of the quality of discs was shown on MRI as well as on clinical assessment.
The reported findings from fairly numerous studies on animal material focused on cellular culture of material sampled from different sites and effects of its implantation into the intervertebral space. In the group without cellular implantation they found fibrous cartilaginous tissue and granulation tissue forming. In the second group, after the implantation, they found cartilaginous tissue and granulation tissue, with cells irregularly scattered in the matrix, revealing a considerable number of proteoglycans and type II collagen but no elastic fibres. The substitute cartilaginous tissue produced by the implanted autologous chondrocytes is the best substitute for the healthy matrix of the nucleus pulposus.
The two cases of a repeated prolapse of a nucleus fibrous fragment provided a unique opportunity for a direct evaluation of the excellent functioning of the transplanted chondrocytes. The chondrocytes obtained from culture integrate well with the intercellular matrix showing normal productive activity in the form of generation of typical matrix components – type I, II, III, IV, IX collagen, proteoglycans and aggrecan, inhibiting the degenerative processes in the nucleus fibrosus and restoring normal balance in the metabolism of the nucleus fibrosus. Correct culture of autologous chondrocytes from material obtained from fragments of the nucleus pulposus removed during surgical procedure allows obtaining a large number of valuable chondrocytes to be used in the treatment of the degenerative disc disease (DDD). However implanted chondrocytes improved the disc matrix, the ADCT procedure was not able to completely prevent the next disc herniation.