Cells of the intervertebral disc exist in an unusual environment compared to those of other tissues. Within the disc there are low levels of nutrients available, low oxygen levels and it is an acidic environment due to high lactate levels. Apoptosis (programmed or controlled cell death) has been reported in intervertebral discs, as well as necrosis (uncontrolled cell death). This study has focused on examining the sensitivity of nucleus pulpo-sus (NP) cells to several stimuli, in comparison to two other cells types. Ultra violet (UV) irradiation, serum starvation (with no foetal calf serum) and treatment with 2mM hydrogen peroxide were used to induce apoptosis in cultured bovine NP cells, HeLa (cancer cell line) and 293T cells (human embryo kidney derived) cells. Apoptosis was identified by nuclear morphology following staining with fluorescent Hoechst 33342 dye and propidium iodide; the incidence was measured at 24, 48 and 72 hours. Untreated controls were used for each treatment and at each time point. The incidence of apoptosis increased with time for all treatments. After 72 hours, UV treatment produced the highest levels of apoptosis with levels of apoptosis occurring in the order of HeLa (94%) >
NP cells (29%) >
293T cells (15%). Treatment with hydrogen peroxide and serum starvation induced apoptosis at lower levels in all three cell types (maximum of 30%). Serum starvation induced apoptosis in only 10% of NP cells at 72 hours, compared to 20% in HeLa cells. None of the controls contained apoptotic cells. NP cells are stimulated to apoptose in response to UV irradiation, hydrogen peroxide and serum starvation. However, levels of apoptosis are much lower after UV treatment in comparison to HeLa cells (3 times lower), suggesting that they may have a protective mechanism to this apoptotic stimulus, compared to HeLa cells. The low levels of apoptosis observed in NP cells with serum starvation may be due to the low nutrient environment that they exist in normally.
normal, grade IV chondral damage, osteochondral defects or endstage osteoarthritis (OA) of the knee, categorised by the cartilage appearance at arthroscopy. Levels of matrix metalloproteinases (MMPs) 2 and 3 and the inhibitor, TIMP 1, were measured in the fluids via ELISA assays. Urea levels were measured in blood and synovial fluids and enzymes and their inhibitors were normalized according to the ratio of serum:SF urea, to account for the dilution factor of the SF (Kraus et al 2001). Western blotting was used to identify the presence of aggrecan components (chondroitin-4-sulphate: 2B6 antibody; C-6-S: 3B3 and C-0-S: 1B5; keratan sulphate: BKS-1; the G1 domain: 7D1; interglobular domain: 6B4) and also enzyme degradation products of MMPs (BC14) and aggrecanases (BC3; BC-13).
The diagnosis of a Massive irreparable rotator cuff tear was confirmed by diagnostic ultrasound scan. The shoulder function was evaluated using the Constant Score. Patients’ active shoulder ranges of motion were recorded and video-recorded as well. Each participant was taught the initial 6-week of self Deltoid muscle exercise, executed in supine, at least three times a day. They were instructed that when they felt better control on their active shoulder movements to gradually recline up the head of the bed and continue with the same simple exercise. They were reviewed at 6 weeks re-assessed and re-taught the same exercise, with a 2kg weight in their hand. At the 12th week they were reassessed using the constant score, and their active range of motion was video recorded again.
16 patients benefited greatly from the surgery and 6 benefited to some extent, giving an overall good result of 71%. 7 patients had no or little relief from surgery (29%). Moderate to severe degenerate changes in SC and IC joints on histology were found in 59% of patients. 91.6 % of these patients did well with surgery. Only 60 % of those with mild changes did well. Discography was possible in five out of six attempted cases. Two were positive and both did well from surgery. Three patients had negative discographies and two of them had a poor result and one had only some relief.
Autologous chondrocyte implantation (ACI) has been used most commonly as a treatment for cartilage defects in the knee and there are few studies of its use in other joints. We describe ten patients with an osteochondral lesion of the talus who underwent ACI using cartilage taken from the knee and were prospectively reviewed with a mean follow-up of 23 months. In nine patients the satisfaction score was ‘pleased’ or ‘extremely pleased’, which was sustained at four years. The mean Mazur ankle score increased by 23 points at a mean follow-up of 23 months. The Lysholm knee score returned to the pre-operative level at one year in three patients, with the remaining seven showing a reduction of 15% at 12 months, suggesting donor-site morbidity. Nine patients underwent arthroscopic examination at one year and all were shown to have filled defects and stable cartilage. Biopsies taken from graft sites showed mostly fibrocartilage with some hyaline cartilage. The short-term results of ACI for osteochondral lesions of the talus are good despite some morbidity at the donor site.
Survey responses were received from 741(61.7%) of the test group and 748 (62.3%) of the control group. A statistically significant increase in the prevalence of the neurological symptoms was seen among orthopaedic surgeons (p<
0.001). A significant increase in musculoskeletal problems (p<
0.008) and muscle pain (p<
0.004) was also found. No significant difference was seen in the prevalence of vascular symptoms. The neurological symptoms were not related to other potential medical causes.
We have used a sheep model of intervertebral disc degeneration to monitor the presence and organisation of nerves in the disc as degeneration progresses. This model has been used to study morphological and bio-chemical changes of the disc as it degenerates, in addition to associated alterations in end-plate vascularity and vertebral bone remodelling. One aspect of this model which has not been studied to date is how the innervation of the disc may change with the onset of degeneration. This is the object of the present study.
Mature human intervertebral disc cells have generally been described as being either fibroblast-like or chondrocyte-like; i.e. appearing either elongated and bipolar or rounded/oval. Fibroblast-like cells are observed within the outer regions of the anulus fibrosus whilst chondrocyte-like cells are found in the more central regions of the disc. However, a few reports have noted that in some circumstances disc cells appear to extend more elaborate cytoplasmic processes into their surrounding extracellular matrix. In this study, we have examined healthy and pathological human intervertebral discs for the presence of the cytoskeletal elements, F-actin and vimentin. Tissues examined included discs of no known pathology, discs with spondylolithesis, scoliosis specimens taken from the convex and concave sides, and degenerated discs. F-actin was not readily observed within discs cells but was a marked feature of vascular tissue within the disc and occasionally seen in infiltrating cells. Vimentin was more readily seen within cells of the inner anulus fibrosus and nucleus pulposus. In general, disc cell morphology was fibrocyte or chondrocyte-like; however, in spondylolisthetic discs, cells with numerous cytoplasmic projections were frequently observed. The differential morphologies and cytoskeletal composition observed in disc cells may be indicative of variations in mechanical strains and/or pathologies, or indeed of cell function.
The aim of this study was to identify potential inflammatory mediators in herniated and non-herniated intervertebral disc. It has been suggested that inflammation of the nerve root is a pre-requisite for disc herniations to be symptomatic. What leads to this inflammation is a matter of conjecture; one possible cause may be inflammatory mediators released from the herniated disc tissue itself. In this study we have examined discs from individuals with and without disc herniations to determine if there is a different degree of occurrence. Twenty two discs from 21 patients with disc herniation were examined together with four discs from patients with other disc disorders and five age-matched discs from individuals obtained at autopsy. Samples were studied for the presence of blood vessels and inflammatory cytokines: IL-1α and β, IL-6, INOS, MCP1, TNFα, TSG-6 and thromboxane. Of the herniated discs 10 were protrusions, six extrusions and six sequestrations. There was less of all the cytokines in the non-herniated discs than found in the herniated, with very little immunostaining for iNOS or IL-1α in any samples. Staining was seen in all herniated samples for IL-1β, but in fewer for IL-six and MCP1 (86%), thromboxane (68%), TNFα (64%) and TSG-6 (59%). The presence of cytokines was strongly associated with the presence of blood vessels. Protruded discs had less TNFα and thromboxane than sequestrated or extruded discs. Cytokines appear to play an active role in the aetiopathogenesis of disc herniations. Some may be involved in the stimulation of degradative enzymes and hence resorption of, for example, sequestrations, whereas others may be responsible for an inflammatory response in the surrounding tissues such as nerve roots.
Although an increased and deeper innervation of painful and degenerate intervertebral discs (IVDs) has been reported, the mechanisms that regulate nerve growth into the IVD are largely unknown. In other tissues, proteoglycans have been found to act as nerve guidance molecules that, generally speaking, inhibit nerve growth. As disc degeneration is characterised by a loss of proteoglycans, we assessed the effects of IVD proteoglycans on nerve growth and guidance. Using in vitro assays of nerve growth, we found that human disc proteoglycans inhibited nerve attachment, neurite extension and induced sensory growth cone turning in a dose-dependent manner. Digestions with chondroitinase ABC or keratinase abrogated these inhibitory effects. Proteoglycans of the anulus fibrosus were more inhibitory than those from the nucleus pulposus. Disc proteoglycans inhibit nerve growth and this inhibitory activity may dependent on proteoglycan glycosylation and/or sulfation. A loss of proteoglycans from degenerative discs may therefore predispose the discs to nerve invasion.
Tissue engineering is an increasingly popular method of addressing pathological disorders of cartilage. Recent studies have demonstrated its clinical efficacy, but there is little information on the structural organisation and biochemical composition of the repair tissue and its relation to the adjacent normal tissue. We therefore analysed by polarised light microscopy and immunohistochemistry biopsies of repair tissue which had been taken 12 months after implantation of autologous chondrocytes in two patients with defects of articular cartilage. Our findings showed zonal heterogeneity throughout the repair tissue. The deeper zone resembled hyaline-like articular cartilage whereas the upper zone was more fibrocartilaginous. The results indicate that within 12 months autologous chondrocyte implantation successfully produces replacement cartilage tissue, a major part of which resembles normal hyaline cartilage.
The articular surface of the humeral head is usually described as facing posteromedially, making an angle of between 16 degrees and 35 degrees with the transepicondylar plane. At hemiarthroplasty the articular surface also appears to be offset posteriorly with respect to the humeral shaft. Coracoid impingement may occur if this offset is not accommodated. An analysis was made of 29 cadaveric humeri using an industrial co-ordinate measuring machine. The position of the centre of the head was defined with respect to the humeral shaft and transepicondylar plane. The humeral articular surface was found to be retroverted by 21.4 degrees and its centre offset posteriorly by 4.7 mm. Previous interpretation of retroversion did not take into account the posterior displacement, and this may be of importance in improving future prosthetic design.
Articular cartilage from the femoral heads of 27 patients having an arthroplasty for subcapital fracture was studied, and its mechanical and chemical properties compared to those of a group of 33 age-matched macroscopically normal autopsy specimens. Water and proteoglycan contents were measured, as were swelling ability, compressive and tensile strength of the cartilage, and the density of the underlying bone. Cartilage from the fracture specimens had a significantly reduced proteoglycan content, as measured by fixed charge density, and increased swelling ability. These results indicate that this group differs from the "normal" population and care should be taken before they are accepted as control material for studies on osteoarthritic cartilage. Another finding was that bone density was much the same in the fracture and the normal group. This casts some doubt upon the concept that patients who sustain subcapital fractures are more osteoporotic than the average for the same age range.
We studied the mechanical and biochemical properties of articular cartilage from 22 osteoarthritic femoral heads obtained at operation and 97 femoral heads obtained at autopsy. Cartilage from the zenith and from the antero-inferior aspect of each head was tested both in tension and in compression. Water content, swelling ability and proteoglycan content were measured, the cartilage was examined histologically and the density of the underlying bone was assessed. Fifty-five of the autopsy specimens were defined as macroscopically normal because they exhibited no progressive fibrillation patterns on staining with Indian ink; but significant changes in water content, bone density and tensile strength related to age were seen in this group. In 20 pairs of femoral heads which were both macroscopically normal, we found, surprisingly, that cartilage from the left and right sides of the same patient was sometimes very different. Compared with the normal autopsy specimens the osteoarthritic specimens had a significantly increased swelling ability, a lower proteoglycan content and impaired mechanical properties, being both weaker in tension and softer in compression. Abnormal autopsy specimens had values intermediate between those of osteoarthritic and normal groups. Results from this abnormal group suggest that there is no primary loss of proteoglycan in early osteoarthritis.
Specific antisera to collagen Types I, II and III and proteoglycan were used to investigate the distributions of these molecules in normal human intervertebral discs. Immunofluorescent staining indicated the presence of small amounts of Type III collagen located pericellularly in normal adult intervertebral discs. This finding had not been demonstrated previously by other methods. Similar specimens of intervertebral discs from 17 patients with scoliosis of varying aetiologies were examined, but no evidence was obtained for primary connective tissue defects. Secondary changes, especially marked vascularisation of the inner annulus, were apparent in a number of scoliotic discs, and some of these showed enhanced staining for collagen Type I and proteoglycan, and intercellular matrix staining for Type III collagen.