Functional Recovery after Surgery for Lumbar Spinal Stenosis in Patients with Hypertension.

Hypertension is a prevalent condition that is associated with lower health status in patients with lumbar spinal stenosis. The study determined whether hypertension is a prognostic factor associated with functional recovery after spine surgery for lumbar spinal stenosis. This was a secondary analysis of the Alberta Lumbar Spinal Stenosis Study in which patients were identified as participants at the time of lumbosacral magnetic resonance imaging or computed tomography in Calgary, Alberta, Canada. Multivariable linear regression analyses were performed to examine hypertension as a prognostic factor of functional recovery after surgery (Oswestry Disability Index, the Swiss Spinal Stenosis (SSS)-Symptom Severity and SSS-Physical Function scales). Of the 97 surgical participants, 49 who were hypertensive were older (76.8, SD 11.4 years) than the 48 non-hypertensive participants (66.7, SD 12.4 years) (p < 0.001). No significant associations between hypertension and post-operative function in any of the three multivariable models were seen. The Oswestry Disability Index mean score improved after surgery (effect size: 1.73; 95%CI: 1.39, 2.06), with no differences seen between those with and without hypertension (p = 0.699). Large changes were seen after surgery for the SSS-Symptom Severity (effect size: 1.0, 95%CI 0.7, 1.3) and SSS-Physical Function (effect size: 0.9, 95%CI 0.6, 1.2) scales. Hypertension alone does not negatively impact functional recovery following surgery.

Forces in spinal cannulation and breaches ex vivo.

BACKGROUND: Pedicle screw insertion, to stabilize or correct the spine, relies on creating a probe path with the correct trajectory to prevent unsafe breaching of the cortical wall. Safe pedicle cannulation is aided when the surgeon can feel the difference between a safe and unsafe path. Pedicle probe forces and torques are currently unknown. The purpose of this study was to investigate the forces and torques encountered while cannulating the pedicle tract in both correct and incorrect cannulations. METHODS: Two experienced surgeons used a standard lumbar probe modified to incorporate a 6 degree-of-freedom load cell to cannulate and breach the T12 to S1 vertebrae of six fresh frozen cadavers (3 males, 3 females, ages 65 to 92). A total of 76 pedicles were tested. FINDINGS: Cannulation axial forces averaged 48 N (standard deviation = 13 N), medial breach 129 N (standard deviation = 25 N), and lateral breach 86 N (standard deviation = 27 N). Cannulation values were significantly lower than the breach values in all 6 degrees of freedom (p < 0.001). There were significant differences between specimens, including males and females, and between degrees of freedom, but no significant right and left differences or by vertebral level. CONCLUSION: A large range of cannulation and breach forces and torques were measured due to variations in bone quality and geometry, as experienced clinically. This is the first time that the absolute and relative force and torque levels have been reported, to our knowledge.

Health-related quality of life and comorbidities associated with lumbar spinal stenosis.

BACKGROUND CONTEXT: Spinal stenosis is one of the most commonly diagnosed pathologies of the lumbar spine and the leading indication for spine surgery in adults aged 65 years and older. Yet, the burden of lumbar spinal stenosis (LSS) alone, and in combination with common comorbidities, on health-related quality of life (HRQL) is unknown as are comorbidities specifically associated with this chronic condition. PURPOSE: To estimate the illness burden of LSS on HRQL, adjusting for the effects of specific comorbidities, age, and gender, and investigate whether specific comorbidities are associated with the condition. STUDY DESIGN/SETTING: A community-based cohort of 245 patients diagnosed with LSS was assembled and compared with a representative sample of 7,489 adults from the base population of Albertans responding to the Canadian Community Health Survey on HRQL and comorbidities. METHODS: Health-related quality-of-life data were acquired through interviews for both groups using the Health Utilities Index Mark 3 (HUI3). Both groups were also queried about the presence of 13 specific chronic conditions. Linear regression was used to model HUI3 scores as a function of group, age, gender, and specific comorbid conditions. Logistic regression was used to compare the odds of having particular comorbid conditions between the LSS and general population groups. RESULTS: The mean unadjusted overall HUI3 scores were 0.60 for the LSS group and 0.85 for the general population (1=perfect health). After adjustment, HRQL deficits four times that deemed a clinically important difference remained between the groups. Controlling age and gender, the prevalence of arthritis, migraines, hypertension, and incontinence was significantly greater in the LSS group as compared with the general population sample. CONCLUSIONS: Diagnosed LSS is associated with a very substantial burden of illness that is compounded by associated comorbidities, with implications for clinical care, health-care policy decisions, and research. Attention to comorbidities is particularly important in LSS.

A population-based survey of back pain beliefs in Canada.

STUDY DESIGN: Population-based survey. OBJECTIVES: To assess the back pain beliefs in 2 provinces in Canada to inform a population-based educational campaign. SUMMARY OF BACKGROUND DATA: Beliefs, attitudes, and recovery expectations appear to influence recovery from back pain, yet prevailing public opinions about the condition have been little studied. METHODS: Telephone surveys were conducted with 2400 adults in 2 Canadian provinces. Surveys included the Back Beliefs Questionnaire, and additional questions concerning age, gender, recent and lifetime back pain, coping strategies for back pain, and awareness and persuasiveness of media information concerning back pain. RESULTS: A high prevalence of back pain was reported, with a lifetime prevalence of 83.8%, and 1-week prevalence of 34.2%. Generally, a pessimistic view of back pain was held. Most agreed that back pain makes everything in life worse, will eventually stop one from working, and will become progressively worse with age. Mixed opinions were observed regarding the importance of rest and staying active. A significant minority (12.3%) reported taking time off from work for their last back pain episode. Those individuals taking time off from work held more negative back pain beliefs, including the belief that back pain should be rested until it gets better. CONCLUSIONS: Public back pain beliefs in the 2 Canadian provinces sampled are not in harmony with current scientific evidence for this highly prevalent condition. Given the mismatch between public beliefs and current evidence, strategies for reeducating the public are needed.