Combined autologous chondrocyte implantation and allogenic meniscus transplantation: a biological knee replacement.

Meniscus deficient knees develop early osteoarthritis in the knee. Autologous Chondrocyte Implantation has provided a new dimension to the treatment of chondral defects in the knee, with 85% good to excellent results and a long-term durable outcome of up-to 11 years. However, it is contraindicated in meniscus deficient knees. Allogenic Meniscus Transplantation gives good symptomatic relief in meniscus deficient knees, with a success rate of 89%. However, it is contraindicated in advanced cartilage degeneration. We hypothesized that combination of these two might be a solution for bone-on-bone arthritis in young individuals. We studied a consecutive series of eight patients, with mean age of 43 years, presenting with large kissing chondral defects, secondary to the previous meniscectomy. All the patients were treated with a combination of Autologous Chondrocyte Implantation and Allogenic Meniscus Transplantation. Mean pre-operative Lysholm score was 49, which rose to mean of 66 at 1 year, an average increase by 16.4 points. Six patients showed significant improvement at one year. MRI scans showed good integration of the menisci with the capsule, without any rejection. Histology confirmed the integration. All the patients could lead an active life-style. Five patients maintained the improvement at a mean follow-up of 3.2 years. We could not find any deleterious effects of the combination of these two techniques. So we conclude that the combination of these two techniques together may act a one step towards a true biological knee replacement.

Tissue repopulation during cure of osteopetrotic (mi/mi) mice using normal and defective (We/Wv) bone marrow.

Resorption of petrotic bone in osteopetrotic (mi/mi) mice was brought about by transplantation of bone marrow to X-irradiated recipients. In an attempt to learn more about the donor cell line involved in this process, both normal and defective marrow were used. The consequent repopulation of the lympho-myeloid complex was monitored by isoenzymes of glucose phosphate isomerase. The progress of normal marrow grafts was contrasted with that of a defective marrow (We/Wv). Despite the observation with We/Wv marrow showed reduced ability to form colonies in the spleen of an irradiated recipient, this marrow was as effective as normal marrow in inducing resorption of petrotic bone. The primordial stem cell for the osteoclast (haematopoietic stem cell?) is thus not a CFUS. Chimaeras with resolution of osteopetrosis by We/Wv bone marrow may exhibit erythropoiesis from residual stem cells of the host but leucocytes and platelets from the donor.

Resolution and relapse of osteopetrosis in mice transplanted with myeloid tissue of variable histocompatibility.

Osteopetrotic microphthalmic mice (mi/mi) were treated by injections of suspensions of myeloid tissue, newborns i.p., and weanlings i.v. Donated syngeneic material effected permanent cure of oteopetrosis provided that the dose was large enough (10(8) cells of bone marrow). H-2-compatible allogeneic bone marrow was initially as effective, but relapse ensued in immunocompetent mice. H-2-incompatible marrow was ineffecitve except in one set of newborn tolerant mice. Total body X-radiation in sublethal doses to recipients allowed permanent cure with H-2-compatible, and, in one circumstance, with H-2-incompatible marrow in smaller doses. The best results were obtained after lethal irradiation and the smaller dose of marrow. Results were checked by chromosome assay demonstrating that cure or relapse was correlated with permanent take or rejection, respectively, of a transplant in a recipient's bone marrow. Retention of donor lymphocytes alone was not associated with effective bony resorption; the candidate cell line for effectiveness remains the haematopoietic stem cell-monocyte-tissue phagocyte.

The cartilage end-plate and intervertebral disc in scoliosis: calcification and other sequelae.

The morphology and composition of the intervertebral disc and also of the cartilage end-plate were studied in patients with idiopathic or congenital scoliosis. The cartilage end-plate was investigated because of its function as an epiphyseal plate in humans and the association between growth and progression of the scoliotic curve. The proteoglycan and water contents were reduced in both structures in specimens from scoliotic patients, particularly toward the concavity of the curve, compared with autopsy material. The distribution of some collagen types differed in tissue from scoliotic patients and autopsy tissue. Calcification of the cartilage end-plate, and sometimes of the adjacent disc, occurred in all but three scoliotic patients, whereas there was minimal calcification in the autopsy specimens. We suggest that, although these changes are probably a secondary response to altered loading in the scoliotic patients, they may be highly significant to the progression of the scoliotic curve.

Biochemical and structural properties of the cartilage end-plate and its relation to the intervertebral disc.

The cartilaginous end-plate is thought to play an important role in the nutrition of the intervertebral disc, and hence may be of significance in the etiology of back pain. The present study describes the biochemical and histologic properties of the end-plate and adjacent tissues in the young human adult lumbar spine. Thus, a datum is established in which to demonstrate variation with location and relationships between properties of different tissues. Results of the chemical analyses show a change in composition through the end-plate with that at the outer annulus and nearer the bone, having higher collagen but lower proteoglycan and water contents, than the end-plate nearest the disc at the nucleus. Histology demonstrated numerous disruptions along the end-plate, with Schmorl's nodes being present in several specimens. Where these occurred, the disc, and in some cases the end-plate, showed loss of proteoglycan compared with the surrounding tissue.

The fluid content of the human intervertebral disc. Comparison between fluid content and swelling pressure profiles of discs removed at surgery and those taken postmortem.

The fluid content of the disc, which governs its mechanical response and biological behavior, varies with external load. Because load on the disc changes after death, the fluid content and swelling pressure profiles of human discs taken at autopsy were measured, and compared with discs removed during surgical procedures. In general, discs taken at surgery had a lower fluid content in the nucleus and a higher fluid content in the outer anulus than discs removed at autopsy. In discs removed at surgery, the swelling pressure of the nucleus was higher than that of the anulus, whereas in autopsy discs the swelling pressure profile was flat. These changes are though to result from changes in load after death, and could influence the results of in vitro mechanical tests on the disc.

1991 Volvo Award in basic sciences. Collagen types around the cells of the intervertebral disc and cartilage end plate: an immunolocalization study.

Several types of collagen are known to exist in the intervertebral disc in addition to the fibrillar collagens, Types I and II. Although they constitute only a small percentage of the total collagen content, these minor collagens may have important functions. This study was designed to investigate the presence of Types I, II, III, IV, VI, and IX collagens in the intervertebral disc and cartilage end plate by immunohistochemistry, thereby establishing their location within the tissues. Types III and VI collagen have a pericellular distribution in animal and human tissue. No staining for Type IX collagen was present in normal human disc, but in rat and bovine intervertebral disc, it was also located pericellularly. These results show that cells of the intervertebral disc and cartilage end plate sit in fibrous capsules, forming chondrons similar to those described in articular cartilage. In pathologic tissue the amount and distribution of the collagen types, and the organization of the pericellular capsule, differ from that seen in control material.

Matrix metalloproteinases and aggrecanase: their role in disorders of the human intervertebral disc.

STUDY DESIGN: A comprehensive immunohistochemical study of matrix metalloproteinase activity in discs from patients with different disc diseases. OBJECTIVES: To identify individual matrix metalloproteinase enzymes that could contribute to the degeneration of the matrix of the intervertebral disc, to identify the cells that produce matrix metalloproteinases (for example, the endogenous disc cells or invading cells associated with vascularisation), and to determine if "aggrecanase" contributes to degradation of proteoglycans in disc disorders. SUMMARY OF BACKGROUND DATA: Matrix disorganization and loss of substance are the most common findings in degenerate discs, and proteinase enzyme activity is one means of causing these changes. METHODS: Forty-nine discs from 46 patients with degenerative disc disease, posterior anular tears, spondylolisthesis, or disc herniation were studied immunohistochemically to determine the presence of matrix metalloproteinases 1, 2, 3, 7, 8, 9 and 13, tissue metalloproteinases 1 and 2, and proteoglycan degradation products generated by either matrix metalloproteinases or aggrecanase activity. In addition, in situ zymography was used to confirm matrix metalloproteinase activity. RESULTS: The most extensive staining was seen for matrix metalloproteinases 1, 2, 3, and 9, with 91%, 71%, 65%, and 72% of samples having some immunopositivity for the respective antibodies. In contrast, staining for matrix metalloproteinases 7 and 8 was much less (38% for both). Tissue inhibitor of metalloproteinases 1 and 2 were expressed in 34% and 79% of specimens, respectively. Matrix metalloproteinases were found particularly in cell clusters and blood vessels of degenerate discs, with staining correlating positively with macroscopic degenerative grade. For all of the enzymes, there was most staining in the herniation specimens and least in the autopsy samples. The opposite was true of staining for the matrix metalloproteinases inhibitor, tissue inhibitor of metalloproteinases 2, with most found in the autopsy specimens. Enzyme activity was confirmed by in situ zymography and staining for matrix metalloproteinase degradation products of proteoglycans. In addition, there was staining with antibodies demonstrating aggrecanase degradation products. CONCLUSIONS: Matrix metalloproteinase activity is more prevalent in herniated discs than in other disc disorders studied, although matrix metalloproteinases may have been more common earlier in the disease progression. Matrix metalloproteinases can be produced by invading blood vessels and associated cells, as well as by indigenous disc cells. Aggrecanase activity, although present in some samples, was not as obvious as that of matrix metalloproteinases. In addition to altered matrix metalloproteinase production, there appears to be a change in the balance between enzymes and endogenous inhibitors, tissue inhibitors of metalloproteinases. This study highlights specific matrix metalloproteinases that might be most efficient to target in developing therapeutics for minimizing degradation of the extracellular matrix of the disc.

Immunohistochemical detection of Schwann cells in innervated and vascularized human intervertebral discs.

STUDY DESIGN: The ingrowth of nerves, blood vessels, and Schwann cells into human intervertebral discs was examined using immunohistochemistry for cell-type-specific markers. OBJECTIVES: To determine whether Schwann cells may contribute to disc innervation, and to assess the relation between disc innervation and vascularization. SUMMARY OF BACKGROUND DATA: Intervertebral disc degeneration was associated previously with ingrowth of blood vessels and nerves. Schwann cells are known to play an important role in regulating nerve growth and survival in other tissues, but they have not been examined in human pathologic intervertebral discs. METHODS: Serial sections of human intervertebral discs were immunostained for the neuronal markers (neurofilament 200, peripherin, protein gene product 9.5), for the Schwann cell marker (glial fibrillary acidic protein), and for the endothelial cell marker (CD34). RESULTS: Glial fibrillary acidic protein-immunopositive cells colocalized with nerves in degenerate discs, but were absent or rarely observed in nondegenerate, aneural discs. These also were seen in the disc matrix, independently of nerves. Much of the nerve and Schwann cell ingrowth was found in vascularized areas of disc tissue, where the lamellar structure of the anulus fibrosus was disrupted. Blood vessels were observed deeper into the discs than nerves or Schwann cells. CONCLUSIONS: The appearance of glial fibrillary acidic protein-immunopositive cells in diseased intervertebral discs was closely associated with nerve ingrowth. This novel finding suggests that Schwann cells have a role to play in regulating disc innervation and nerve function in the disc. Because blood vessels were observed furthermost into the disc, it is possible that degenerate disc vascularization occurs before innervation.

Mechanoreceptors in intervertebral discs. Morphology, distribution, and neuropeptides.

STUDY DESIGN: The present study investigated the occurrence and morphology of mechanoreceptors in human and bovine intervertebral discs and longitudinal ligaments. OBJECTIVE: To determine the type and frequency of mechanoreceptors present in intervertebral discs and anterior longitudinal ligaments in two patient groups, those with low back pain and those with scoliosis. Bovine coccygeal discs were examined. SUMMARY OF BACKGROUND DATA: Nerves have been described in intervertebral tissues, but there is little information on the endings of these nerves and their receptors, stimulation of which can cause a nerve impulse. METHODS: The presence of mechanoreceptors were investigated by immunolocalization of nerves and neuropeptides. By examining sequential sections, the frequency of receptors was assessed. RESULTS: Immunoreactivity to neural antigens showed mechanoreceptors in the anulus fibrosus and longitudinal ligaments of bovine and human specimens. Their morphology resembled Pacinian corpuscles, Ruffini endings, and, most frequently, Golgi tendon organs. They were found in 50% of discs investigated from patients with low back pain and in 15% of those with scoliosis. CONCLUSIONS: Mechanoreceptors were found in the outer 2-3 lamellae of the human intervertebral disc and anterior longitudinal ligament. Physiologic studies in other tissues indicate that these provide the individual with sensation of posture and movement, and in the case of Golgi tendon organs, of nociception. In addition to providing proprioception, mechanoreceptors are thought to have roles in maintaining muscle tone and reflexes. Their presence in the intervertebral disc and longitudinal ligament can have physiologic and clinical implications.

Changes in collagen cross-linking in degenerative disc disease and scoliosis.

STUDY DESIGN: Biochemical study of the changes in the collagen cross-link profile of human intervertebral discs collected at surgery from patients with either low back pain associated with disc degeneration or scoliosis. OBJECTIVE: To determine whether changes occur in the collagen cross-link profile in the disc of patients with either low back pain associated with disc degeneration or scoliosis, which may well influence matrix integrity. Such changes in the cross-link profile of a tissue indicates increased matrix turnover and tissue remodeling and may have implications for the progression of these disorders. SUMMARY OF BACKGROUND DATA: The diseases of the intervertebral disc, degenerative disc disease and scoliosis, are both characterized by changes in the extracellular matrix components that will affect the mechanical function of the tissue. The stability of the collagenous components and hence the mechanical integrity of connective tissues such as the disc is dependent on the degree and type of cross-links between the collagen molecules. This article reports results on the distribution of the different cross-links in the disc and the changes that occur with age, degenerative disc disease, and scoliosis. METHODS: Thirty-three discs were obtained from patients with degenerative disc disease and 29 discs from patients with scoliosis. Samples were acid hydrolyzed and the collagen cross-links analyzed by either fractionation on an amino acid analyzer configured for cross-link analysis using ninhydrin postcolumn detection or fractionation by high-pressure liquid chromatography with fluorescence detection. RESULTS: The reducible cross-links and the mature cross-link all increased from the outer anulus fibrosus through into the nucleus pulposus. The highest levels of the mature cross-link were found in the cartilage end-plate. The nonenzymic derived cross-link, pentosidine, in contrast, showed little difference across the disc, but did show the expected age-related increase. In degenerative disc disease, no change in the levels of the reducible or mature cross-links was found, but a decrease was observed in the levels of the age-related cross-link pentosidine in the more severe disease samples. In scoliosis, significantly higher levels of the reducible cross-links were found on the convex than on the concave side of the scoliotic disc. CONCLUSIONS: These changes in the cross-link profile of the intervertebral disc in degenerative disc disease and scoliosis are indicative of increased matrix turnover and tissue remodeling and likely to have implications for the progression of these disorders.

Innervation of the spondylolysis "ligament".

SUMMARY OF BACKGROUND DATA: Spondylolysis of the lower lumbar vertebrae is a non-united childhood fracture of the arch of the vertebra, persisting into adult life. Symptoms of disabling low back pain appear in a minority of patients, usually for the first time in adulthood. This pain is considered to arise from several separate sources, one of which may be the spondylolysis ligament. STUDY DESIGN: The innervation of the ligament has been investigated immunohistochemically. METHODS: Specimens from eight patients were divided longitudinally for histology including hematoxylin and eosin, toluidine blue, and elastic van Gieson. Histochemistry involved immunostaining for the neuropeptides: protein gene product, calcitonin gene related peptide, substance P, vasoactive intestinal peptide, and the c-flanking peptide of neuropeptide Y. RESULTS: Immunoreactivity to calcitonin gene-related peptide, the c-peptide of neuropeptide Y, and vasoactive intestinal peptide was identified in the ligament or in the adjacent adipose tissue. CONCLUSION: The movement that the ligament allows at the fracture site may result in stimulation of the nerve endings both in the ligament and in the surrounding soft tissue.

[IgM kappa lymphoma with antisulfatide antibodies revealed by cervical motor neuropathy simulating amyotrophic lateral sclerosis]. / Lymphome à IgM kappa avec anticorps antisulfatides révélé par une neuropathie motrice cervicale simulant une sclérose latérale amyotrophique.

INTRODUCTION: It is well known that polyneuropathy is associated with monoclonal IgM kappa. EXEGESIS: We report the case of a 79-year-old man with lymphoma and motor neuron disease at cervical level simulating amyotrophic lateral sclerosis (ALS). Neurological deficit with inflammatory process evolved within 4 months. Electrophysiological findings showed increased and enlarged muscular potentials with neurogenic patterns. Nerve conduction velocities were normal, with neither multifocal neuropathy nor persistent conduction blocks. Besides mixed cryoglobulinemia type II, antisulfatide antibodies issued from monoclonal IgM were found. They were directed against myelin glycosphingolipids. No antiganglioside GM1 antibodies could be detected. This not only evoked ALS but also proximal motor axonopathy related with monoclonal IgM. CONCLUSIONS: This case suggests that antisulfatide antibodies often present in sensitive demyelinating polyneuropathy could also be involved in lower motor neuron syndrome.

[Renin plasmatic activity and plasma aldosterone in three cases of pheochromocytoma (author's transl)]. / Phéochromocytomes, activité rénine et aldostérone.

Renin Plasmatic Activity (R.P.A.) was increased in three cases of Pheochromocytoma Plasmatic aldosterone (A), measured in one patient, was high in the supine position and increased considerably in orthostatism. This was not observed with the R.P.A.7. Urine Tetra Hydroaldosterone (T.H.A.) was increased in two of the three patients and this increase corresponded to the Pheochromocytoma in which the V.M.A. concentrations were the highest. P.R.A., T.H.A. and V.M.A. regained normal values after surgery. We suggest that there is a certain parrallelism between the increase in the excretion of A. and the importance of the catécholamine release from the Pheocchromocytoma.

Injectable hydrogels with high fixed charge density and swelling pressure for nucleus pulposus repair: biomimetic glycosaminoglycan analogues.

The load-bearing biomechanical role of the intervertebral disc is governed by the composition and organization of its major macromolecular components, collagen and aggrecan. The major function of aggrecan is to maintain tissue hydration, and hence disc height, under the high loads imposed by muscle activity and body weight. Key to this role is the high negative fixed charge of its glycosaminoglycan side chains, which impart a high osmotic pressure to the tissue, thus regulating and maintaining tissue hydration and hence disc height under load. In degenerate discs, aggrecan degrades and is lost from the disc, particularly centrally from the nucleus pulposus. This loss of fixed charge results in reduced hydration and loss of disc height; such changes are closely associated with low back pain. The present authors developed biomimetic glycosaminoglycan analogues based on sulphonate-containing polymers. These biomimetics are deliverable via injection into the disc where they polymerize in situ, forming a non-degradable, nuclear "implant" aimed at restoring disc height to degenerate discs, thereby relieving back pain. In vitro, these glycosaminoglycan analogues possess appropriate fixed charge density, hydration and osmotic responsiveness, thereby displaying the capacity to restore disc height and function. Preliminary biomechanical tests using a degenerate explant model showed that the implant adapts to the space into which it is injected and restores stiffness. These hydrogels mimic the role taken by glycosaminoglycans in vivo and, unlike other hydrogels, provide an intrinsic swelling pressure, which can maintain disc hydration and height under the high and variable compressive loads encountered in vivo.