Objective: To determine if (a) inflammatory mediators are present in herniated intervertebral discs and (b) if their presence correlates with inflammation of nerve roots or symptoms.

Design: Inflammation was assessed with gadolinium enhancement of MRI. Neurological compromise was measured. Disc tissue was examined for inflammatory mediators IL-1α and β, IL-6, MCP-1, TSG-6, iNOS, TNFα and thromboxane.

Patients: Sixty-five discs were removed from 64 patients undergoing surgery for disc prolapse.

Outcome measures: We developed (i) an MRI score to assess inflammation radiologically prior to surgery (n=28, mean 4.9±6.8 days), (ii) a Surgical Score to assess inflammation of the nerve roots at surgery (n=44), (iii) a Clinical Score to determine pain, disability and neurological compromise (n=17) and (iv) a Mediator Score to reflect the number and amount of inflammatory mediators present (n=20).

Results: Thirty percent of the prolapses in this study were extrusions, 19% sequestrations and 51% protrusions. Sixteen of the 28 patients with gadolinium had nerve root enhancement (86% of the extrusions, 57% of sequestrations, and 43% of protrusions), whilst 19 had enhancement of or around the disc herniation itself (71% of the extrusions, 86% of sequestrations and 57% of protrusions). The Mediator Scores were highest for the sequestrations (as was the Surgical Score) and lowest for the protrusions, but extruded discs had most IL-1α and β, IL-6, TNFα and thromboxane. Extruded discs had the highest Clinical Score and sequestrated the lowest.

Conclusions: Mediators produced in prolapsed disc appear to play an important role in inflammation of adjacent tissue and nerve roots. The type of mediator present and proximity of the prolapse to the nerve root may be the important factors in determining which pro-lapses are the most painful.

Objective: To identify risk factors associated with patients that required revision surgery for sciatica.

Design: A retrospective study of 580 patients who underwent surgery for intractable sciatica attributable to pro-lapsed lumbar intervertebral disc from 1986 to 2000 inclusive.

Subjects: The study included a total of 580 patients. Of these seven patients had an operation at two levels, 25 patients had had a primary operation elsewhere and were therefore excluded; four sets of notes remain missing. The total number of primary operations analysed was therefore 558.

Outcome measures: Parameters such as gender, age, level and side of discectomy were entered into a database for analysis. Diagnostic and clinical parameters were also entered; these included the value of the angle of the straight leg raise recorded and absence or presence of neurological deficit (altered sensation, reduced motor power, and absent or diminished reflexes). Operative findings recorded and entered were the type of disc at operation (i. e. protrusion, extrusion and sequestration) and the presence of free cerebrospinal fluid (CSF), however minor, indicating a dural tear.

Results: The total number of primary discectomies was 558 of which 43 went on to require a second operation, giving a revision rate of 7.71%. Of the primary discectomies, 356 were protrusions, 92 extrusions and 110 sequestration. Of the 43 that went onto revision surgery, 35 were protrusions, two extrusion and six sequestration. A significant association was found with primary disc protrusions, this type of disc prolapse was almost three times more likely to go on to need revision surgery compared to extruded or sequestrated discs. Data analysed on primary protrusions showed these patients had a significantly greater straight leg raise angle and reduced incidence of positive neurological findings and so could be identified clinically.

Conclusions: This lead us to conclude that the group of patients with primary protrusions could be selected out and treated conservatively since they are three times more likely to require revision surgery.

Objective: The shape of articular chondrocytes regulates their function, changes in response to mechanical load and is altered in osteoarthritis. We aimed to identify the shape of intervertebral disc cells in pathological and normal tissue.

Design: Immunohistology of human intervertebral discs using cytoskeletal markers to examine disc cell shape.

Subjects: Intervertebral discs from patients with degeneration (n=3), scoliosis (n=3), spondylolisthesis (n=3) and from non-pathological cadaveric spines (n=3).

Outcome measures: (i). Cell shape and (ii). Organisation/ content of cytoskeleton.

Results: In degenerate and normal discs, cells of the anulus fibrosus were generally elongated and bipolar, whilst those of the nucleus pulposus were rounded/oval. However, in localised areas, cells were observed with multiple cytoplasmic processes that extended into the discal matrix. In central regions of scoliotic and, most markedly, spondylolisthetic discs, such cells were more frequent. Their processes were vimentin positive (but F-actin negative) and reached up to 80μm in length. F-actin was clearly present in endothelial cells of blood vessels but absent in disc cells. In contrast, vimentin was expressed by disc cells within the discs’ inner regions, but not towards the outer anulus fibrosus.

Conclusions: The altered shape of disc cells in pathological tissue may reflect areas of abnormal loading. These changes are also likely to affect/reflect altered cell function and therefore have a role to play in the pathological process.