G. Németh

Health-related quality of life (EQ-5D) before and one year after surgery for lumbar spinal stenosis

We investigated the pre-operative and one-year post-operative health-related quality of life (HRQoL) outcome by using a Euroqol (EQ-5D) questionnaire in 230 patients who underwent surgery for lumbar spinal stenosis. Data were obtained from the National Swedish Registry for operations on the lumbar spine between 2001 and 2002. We analysed the pre- and postoperative quality of life data, age, gender, smoking habits, pain and walking ability. The relative differences were compared to a Swedish EQ-5D population survey. The mean age of the patients was 66 years, and there were 123 females (53%). Before the operation 62 (27%) of the patients could walk more than 500 m. One year after the operation 150 (65%) were able to walk 500 m or more. The mean EQ-5D score improved from 0.36 to 0.64, and the HRQoL improved in 184 (80%) of the patients. However, they did not reach the level reported by a matched population sample (mean difference 0.18). Women had lower pre- and post-operative EQ-5D scores than men. Severe low back pain was a predictor for a poor outcome.

Quality of life after a subtrochanteric fracture A prospective cohort study on 87 elderly patients

BACKGROUND The subtrochanteric fracture constitutes approximately 5-10% of all hip fractures. This particular fracture type, owing to its configuration and instability, poses significant challenges to the fixation method, especially in elderly patients with varying degrees of osteoporosis. There has been a gradual change in the operative techniques used to stabilise these fractures leading to the current widespread use of cephalomedullary nails. In contrast to the field of research on patients with the more common femoral neck and trochanteric fractures, few studies have evaluated the health-related quality of life (HRQoL) in patients with subtrochanteric fractures. OBJECTIVE To report the long-term outcome for patients with subtrochanteric fractures treated with a cephalomedullary nail with special regard to the HRQoL. SETTING Four university hospitals. DESIGN A prospective cohort study with a 2-year follow-up. PATIENTS AND METHODS Eighty-seven consecutive elderly patients with a subtrochanteric fracture treated with a cephalomedullary nail. Main outcome measurements were mortality rate, reoperation rate, pain at the hip, walking ability, activities of daily living (ADL) function and HRQoL assessed with the EQ-5D (EQ-5D(index) score). RESULTS The EQ-5D(index) score decreased from 0.73 before fracture to 0.53 at 4 and 12 months and to 0.52 at 24 months. At the final follow-up 80% of the patients reported no or only limited pain at the hip, 46% had regained their prefracture walking ability, 48% their prefracture level of ADL function and 71% had living conditions similar to those before the fracture. The reoperation rate was 8%. The mortality rate was 8% at 4 months, 14% at 12 months and 25% at 24 months. CONCLUSIONS A subtrochanteric fracture in elderly patients had a substantial negative effect on both their short and long-term HRQoL. Although pain at the hip was not a major problem there was an obvious deterioration in walking ability and ADL function. However, the rate of revision surgery was comparatively low which confirms that the cephalomedullary nail constitutes a safe treatment for elderly patients with a subtrochanteric fracture. The data on HRQoL obtained in this study can be used in future healthcare evaluations and to calculate quality-adjusted life-years (QALYs).

Health-related quality of life in patients before and after surgery for a herniated lumbar disc

We investigated the pre-operative and one-year post-operative health-related quality of life (HRQOL) outcome by using a Euroqol (EQ-5D) questionnaire in 263 patients who had undergone surgery for herniation of a lumbar disc. Data from the National Swedish Register for lumbar spinal surgery between 2001 and 2002 were used and, in addition, a comparison between our cohort and a Swedish EQ-5D population survey was performed. We analysed the pre- and post-operative quality of life data, age, gender, smoking habits, pain and walking capacity. The mean age of the patients was 42 years (20 to 66); 155 (59%) were men and 69 (26%) smoked. Pre-operatively, 72 (17%) could walk at least 1 km compared with 200 (76%) postoperatively. The mean EQ-5D score improved from 0.29 to 0.70, and the HRQOL improved in 195 (74%) of the patients. The pre-operative score did not influence the post-operative score. In most patients, all five EQ-5D dimensions improved, but did not reach the level reported by an age- and gender-matched population sample (mean difference 0.17). Predictors for poor outcome were smoking, a short pre-operative walking distance, and a long history of back pain.

Spinal stenosis surgery in Sweden 1987–1999

Despite being recognised for many years as a clinical diagnosis, no exact definition of spinal stenosis has yet been agreed, leading to difficulties in interpreting and comparing studies of the incidence, prevalence and treatment. This study presents the first analysis of national data to be reported. It is a retrospective population-based national register study, aimed at analyzing surgical interventions in patients with lumbar spinal stenosis, patient characteristics, subsequent development, and case fatality rate, based on Swedish national data for 1987–1999. Complete follow-up data were obtained of incidence and type of spinal stenosis surgery, rate of multiple operations, mortality, underlying causes of death, length of hospital stay, and case fatality rate by linkage of the National Inpatient Register and Swedish Death Register. The study cohort consisted of 10,494 patients. Laminectomy was performed in 89%, and additional fusion in 11%. The mean annual rate of operations was 9.7 per 100,000 inhabitants, the annual number of operations performed increased from 4.7 to 13.2 per 100,000 inhabitants per year. The case fatality rate within 30 days after surgery was 3.5 per 1000 operations. Cardiovascular disease was the most common cause of death (46%). Relative risk of dying within 30 days of admission was doubled in men, and for fusion surgery, and increased four fold in patients older than 80 years. The relative risk of dying decreased during the study period. The results show that spinal stenosis surgery in Sweden has increased, and is associated with a low risk. Within an ageing group of patients, mortality has declined.

Surgery for herniation of a lumbar disc in Sweden between 1987 and 1999. An analysis of 27,576 operations.

The National Inpatient Register and the Swedish Death Register were linked to determine the incidence of surgical intervention, the trends and characteristics of the patients, the death rate and the pre- and post-operative admissions for herniation of a lumbar disc based on comprehensive national data between 1987 and 1999. There were 27,576 operations which were followed cumulatively for 155,249 years, with a median of 6.0 years. The mean annual rate of operation was 24 per 100,000 inhabitants, the median age of the patients was 42 years. The 30-day death rate was 0.5 per 1000 operations. The rates of re-operation at one and ten years were 5% and 10%, respectively, decreasing significantly (40%) with time. The mean length of stay decreased from nine to five days. Patients who had been in hospital because of a previous spinal disorder had a significantly higher risk of readmission.

Motion analysis of total cervical disc replacements using computed tomography: Preliminary experience with nine patients and a model

Background Cervical total disc replacement (CTDR) is an alternative to anterior fusion. Therefore, it is desirable to have an accurate in vivo measurement of prosthetic kinematics and assessment of implant stability relative to the adjacent vertebrae. Purpose To devise an in vivo CT-based method to analyze the kinematics of cervical total disc replacements (CTDR), specifically of two prosthetic components between two CT scans obtained under different conditions. Material and Methods Nine patients with CTDR were scanned in flexion and extension of the cervical spine using a clinical CT scanner with a routine low-dose protocol. The flexion and extension CT volume data were spatially registered, and the prosthetic kinematics of two prosthetic components, an upper and a lower, was calculated and expressed in Euler angles and orthogonal linear translations relative to the upper component. For accuracy analysis, a cervical spine model incorporating the same disc replacement as used in the patients was also scanned and processed in the same manner. Results Analysis of both the model and patients showed good repeatability, i.e. within 2 standard deviations of the mean using the 95% limits of agreement with no overlapping confidence intervals. The accuracy analysis showed that the median error was close to zero. Conclusion The mobility of the cervical spine after total disc replacement can be effectively measured in vivo using CT. This method requires an appropriate patient positioning and scan parameters to achieve suitable image quality.

Model studies on segmental movement in lumbar spine using a semi-automated program for volume fusion.

Objective: To validate a new non-invasive CT method for measuring segmental translations in lumbar spine in a phantom using plastic vertebrae with tantalum markers and human vertebrae. Material and Methods: One hundred and four CT volumes were acquired of a phantom incorporating three lumbar vertebrae. Lumbar segmental translation was simulated by altering the position of one vertebra in all three cardinal axes between acquisitions. The CT volumes were combined into 64 case pairs, simulating lumbar segmental movement of up to 3 mm between acquisitions. The relative movement between the vertebrae was evaluated visually and numerically using a volume fusion image post-processing tool. Results were correlated to direct measurements of the phantom. Results: On visual inspection, translation of at least 1 mm or more could be safely detected and correlated with separation between the vertebrae in three dimensions. There were no significant differences between plastic and human vertebrae. Numerically, the accuracy limit for all the CT measurements of the 3D segmental translations was 0.56 mm (median: 0.12; range: −0.76 to +0.49 mm). The accuracy for the sagittal axis was 0.45 mm (median: 0.10; range: −0.46 to +0.62 mm); the accuracy for the coronal axis was 0.46 mm (median: 0.09; range: −0.66 to +0.69 mm); and the accuracy for the axial axis was 0.45 mm (median: 0.05; range: −0.72 to + 0.62 mm). The repeatability, calculated over 10 cases, was 0.35 mm (median: 0.16; range: −0.26 to +0.30 mm). Conclusion: The accuracy of this non-invasive method is better than that of current routine methods for detecting segmental movements. The method allows both visual and numerical evaluation of such movements. Further studies are needed to validate this method in patients.

A New CT Method for Assessing 3D Movements in Lumbar Facet Joints and Vertebrae in Patients before and after TDR.

This study describes a 3D-CT method for analyzing facet joint motion and vertebral rotation in the lumbar spine after TDR. Ten patients were examined before and then three years after surgery, each time with two CT scans: provoked flexion and provoked extension. After 3D registration, the facet joint 3D translation and segmental vertebral 3D rotation were analyzed at the operated level (L5-S1) and adjacent level (L4-L5). Pain was evaluated using VAS. The median (±SD) 3D movement in the operated level for the left facet joint was 3.2 mm (±1.9 mm) before and 3.5 mm (±1.7 mm) after surgery and for the right facet joint was 3.0 mm (±1.0 mm) before and 3.6 mm (±1.4 mm) after surgery. The median vertebral rotation in the sagittal plane at the operated level was 5.4° (±2.3°) before surgery and 6.8° (±1.7°) after surgery and in the adjacent level was 7.7° (±4.0°) before and 9.2° (±2.7°) after surgery. The median VAS was reduced from 6 (range 5–8) to 3 (range 2–8) in extension and from 4 (range 2–6) to 2 (range 1–3) in flexion.