Infratentorial stereotactic biopsy. A review of 11 cases.

A review of the stereotactic cases performed at the University of Iowa between February, 1985, and December, 1990, yielded 12 infratentorial stereotactic biopsies in 11 patients. A definitive diagnosis was obtained in 9 of 11 patients. One patient required a second biopsy to obtain a diagnosis and 1 yielded cystic fluid only. The pathological diagnosis obtained included 4 high-grade gliomas, 2 undifferentiated adenocarcinomas, 2 low-grade astrocytomas, 1 malignant ependymoma, 1 pontine hematoma and 1 cyst. None of the patients experienced increased neurological deficit following biopsy and there was no mortality. One patient developed postoperative meningitis. We conclude that stereotactic biopsy of infratentorial lesions can be performed safely with a high probability of obtaining a diagnosis. Adequate tissue diagnosis is necessary to direct further therapy.     

Biomechanical studies of a dynamized anterior thoracolumbar implant

STUDY DESIGN: An in vitro investigation into the biomechanical properties of a dynamized anterolateral compression implant that allows controlled subsidence. OBJECTIVES: To determine the extent to which both modes of the anterolateral compression implant (controlled collapsing and rigid) are able to reestablish the stability of the lumbar spine after L4 corpectomy. SUMMARY OF BACKGROUND DATA: Over time, anterior and posterior spinal implants have been associated with progressive angulation, and occasionally implant failure and breakage. To circumvent this occurrence and provide better graft loading, dynamized or collapsing devices for clinical use have been developed. METHODS: Eight fresh calf spines (L1-L6) were placed in a biomechanical testing frame. Pure moments of 6 Nm were loaded onto the intact spine in six directions: flexion, extension, right and left lateral bending, and right and left axial rotation. A total L4 corpectomy then was performed, and the defect grafted with a wooden dowel. Loading was repeated after the specimens were stabilized using the two modes of the anterolateral compression implant in succession. RESULTS: The results showed that both modes of the implant (the rigid mode in particular) restore the stiffness of the unstable spine to normal levels of flexion, extension, and right and left lateral bending, even to levels exceeding normal. These devices, however, fall short of achieving normal stability in right and left axial rotation. CONCLUSION: In the cadaveric calf spine after L4 corpectomy, restoration of stability with a dynamized anterior spinal implant is possible in flexion, extension, and right and left lateral bending, but not in axial rotation.     

Clinical measurement, statistical analysis, and risk-benefit: controversies from trials of spinal injury

BACKGROUND: The National Acute Spinal Cord Injury Studies have been a series of trials assessing the role of pharmacologic agents in the prevention of secondary neuronal damage after acute spinal cord injury. METHODS: The trials were multicenter randomized, controlled studies. RESULTS: Two trials have demonstrated the efficacy of high-dose methylprednisolone in improving neurologic and functional recovery and have shown a reassuring safety profile. CONCLUSION: This study responds to a recent commentary on these trials and examines in particular the roles of clinical measurement, statistical analysis, and risk benefit in assembling evidence for or against innovative therapies.     

Low prevalence of antibodies to glucose-6-phosphate isomerase in patients with rheumatoid arthritis and a spectrum of other chronic autoimmune disorders

OBJECTIVE: Arthritis in the K/BxN mouse model results from pathogenic immunoglobulins that recognize glucose-6-phosphate isomerase (GPI), a glycolytic enzyme residing in the cytoplasm of all cells. Antibodies directed against GPI can, alone, transfer arthritis to healthy recipients. Previous experiments have revealed significant titers of anti-GPI antibodies in the serum of many patients with rheumatoid arthritis (RA). We evaluated the generality of these observations in cohorts of patients with 12 different arthritic and chronic autoimmune diseases and in population-matched healthy control subjects. METHODS: Anti-GPI antibodies were assayed in 811 individual serum samples by enzyme-linked immunosorbent assay with 2 forms of GPI, recombinant and native. Results were confirmed by immunoblotting. RESULTS: Several patients had significantly elevated anti-GPI antibody titers, but without the prevalence or the specificity reported previously. Only 15% of RA patients had anti-GPI antibodies (range 12-29% in different cohorts), with a higher prevalence in patients with active disease. Psoriatic arthritis, undifferentiated arthritis, and spondylarthropathy patients also displayed anti-GPI antibodies at similar frequencies (12-25%). Similar titers were detected in a proportion (5-10%) of control subjects or patients with Crohn's disease or sarcoidosis. Very high titers were found in rare cases of RA and systemic lupus erythematosus. CONCLUSION: No disease-specific pattern of antibody positivity to GPI was apparent. While the antibody-mediated mechanism at play in the mouse model may exemplify a generic mechanism for some forms of arthritis in humans, GPI itself does not appear to be a target common to the majority of RA patients.     

Alternative grafts in anterior cervical fusion

Objective

The present retrospective study was conducted to compare the clinical and radiographic outcomes in patients undergoing anterior cervical discectomy with fusion (ACDF) using carbon fiber reinforced polymer (CFRP) cages, or allograft.

Methods

We retrospectively reviewed cases of ACDF using allograft in 20 patients, and CFRP in 19 who had sequential radiographs before and after surgery, and at 1 year.

Results

There were no apparent significant differences between the 2 groups in age (p = 0.057), gender (p = 0.635), or complications (p = 0.648). At 12 months, there were no cases of construct failure, and fusion appeared to have been achieved in patients of both groups. Lordosis was increased significantly in both groups after surgery (p < 0.001 in allograft and p = 0.025 in CFRP), and was maintained up until 1 year (p < 0.018 in allograft and p = 0.05 in CFRP) without a difference between groups (p = 0.721). Anterior interbody height was significantly increased (p < 0.001 in both groups at each time points) after surgery, without a significant difference between groups (p > 0.21). This increase in height was greatest in magnitude immediately after surgery, and declined with the passage of time. There was no detectable health-related quality of life difference between allograft and CFRP group after surgery (p > 0.05).

Conclusion

The present study demonstrates that CFRP cages appear to have comparable fusion rates, restoration of lordosis and disc space height, and complication rates to patients who undergo ACDF with allograft.     

Factors associated with time to diagnosis in early rheumatoid arthritis

Early diagnosis and treatment yield optimal outcomes in rheumatoid arthritis (RA); thus, barriers to disease recognition must be identified and addressed. We determined the impact of sociodemographic factors, medical comorbidities, family history, and disease severity at onset on the time to diagnosis in early RA. The Canadian early ArThritis CoHort study data on 1,142 early RA patients were analyzed for predictors of time to diagnosis using regression analysis. Sociodemographic factors (age, sex, income strata, education, ethnicity), measures of disease activity (joint counts, DAS28 score, acute-phase reactants, patient global evaluation, function), family history, serology, chronic musculoskeletal and mental health conditions, and obesity at diagnosis were considered. In multivariate linear regression analysis, more swollen joints (β = ?0.047 per joint, 95 % CI ?0.085, ?0.010, p = 0.014), higher erythrocyte sedimentation rate (ESR) (β = ?0.012 per 1 mm/h, 95 % CI ?0.022, ?0.002, p = 0.0018), and worse patient global scores (β = ?0.082 per 1 unit on a visual analogue scale, 95 % CI ?0.158, ?0.006, p = 0.034) at baseline predicted a shorter time to diagnosis. Anti-cyclic citrullinated peptide (anti-CCP) antibody positivity (β = 0.688, 95 % CI 0.261, 1.115, p = 0.002) and low income (annual <$20,000 β = 1.185, 95 % CI 0.227, 2.143, p = 0.015; annual $20,000–50,000 β = 0.933, 95 % CI 0.069, 1.798, p = 0.034) increased time to diagnosis. In the logistic regression models, the odds of being diagnosed within 6 months of symptom onset were increased for each swollen joint present [odds ratio (OR) 1.04, 95 % CI 1.02–1.06 per joint], each 1 mm/h elevation in the ESR (OR 1.01, 95 % CI 1.00–1.02), and decreased for patients who were either rheumatoid factor or anti-CCP positive compared to both factors being negative (OR 0.68, 95 % CI 0.51–0.91). Higher disease activity results in a more rapid diagnosis for Canadian patients with early RA, but those with lower income have delays in diagnosis. Strategies to identify patients with a less severe disease presentation and in lower socioeconomic strata are needed to ensure equal opportunity for optimal management.     

Surgical options in the treatment of subaxial cervical fractures: A retrospective cohort study

Objective

To compare clinical and radiographic parameters and outcomes in patients undergoing anterior vs. posterior surgery in unstable cervical subaxial spine fractures.

Methods

We analyzed a group of 33 patients with reducible cervical subaxial fractures. Patients underwent anterior or posterior cervical instrumentation. Inpatient and outpatient records were retrospectively reviewed, and the multiple pre-operative and post-operative clinical and radiographic factors were recorded and analyzed.

Results

Posterior cervical fixation was performed in 15 patients, and anterior cervical fixation in 18 patients. Operative time, blood loss, and number of levels instrumented were all significantly less in the anterior than the posterior cervical group. There was no difference in patient age, surgical complications, follow-up ASIA score, Rand SF-36 evaluation, or cost analysis between the two groups. Mean follow-up time was 11.8 ± 7 months. All patients achieved bony fusion and good alignment at follow-up.

Conclusions

In patients with reducible cervical subaxial dislocations, posterior cervical fixation entails a larger number of fused segments. Anterior surgery is associated with shorter operative times and less blood loss. Anterior instrumentation with interbody grafting can be the initial choice of treatment for stabilization for this subgroup of patients. Posterior surgery is indicated if radiographs after anterior instrumentation show failure.     

Infrared spectroscopy: shedding light on synovitis in patients with rheumatoid arthritis

OBJECTIVES: It is difficult to determine the extent of synovial involvement early in the course of rheumatoid arthritis. A spectroscopic technique was used to characterize the synovium of the small finger joints in both early and late rheumatoid arthritis. This synovium was also compared against normal joints. METHODS: Near-infrared spectroscopy assesses the absorption of near-infrared light by specific joints, giving a characteristic "fingerprint" of the properties of the underlying tissues. Triple measurements by infrared spectroscopy were taken at the bilateral second and third metacarpophalangeal joints. Multivariate analysis was applied. RESULTS: Analysis was able to demonstrate relationships between the specific sources of spectral variation and joint tenderness or swelling as well as radiographic damage. Further use of multivariate analysis allowed recognition of the spectral patterns seen in early disease vs late rheumatoid arthritis and correct classification of over 74% of the joints. CONCLUSIONS: The spectral regions where differences occurred were in the absorption bands related to tissue oxygenation status, allowing the provocative implication that this technique could be detecting ischaemic changes within the joint. Near-infrared spectroscopy may thus be able to provide us with some information about the biochemical changes associated with synovitis.