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Observational study. To evaluate adjacent segment disk degeneration (ASD) after fusion without attempted reduction at a young age for high-grade isthmic spondylolisthesis. The clinical relevance of ASD remains unclear. Previous studies have shown that spinal fusion is associated with increased ASD but without influence on clinical outcome. Since high-grade spondylolisthesis is a severe kyphotic deformity, one could hypothesize that fusion without attempted reduction in young patients leads to accelerated adjacent segment disk degeneration in adult life. Anterior and posterior disk heights were evaluated on supine radiographs of the spine 8 years and 29 years after fusion without attempted reduction for high-grade spondylolisthesis and also on standing radiographs 8 years and 33 years after surgery. Pelvic parameters were evaluated on standing radiographs obtained 33 years after surgery. Health-related quality of life was evaluated with the Scoliosis Research Society (SRS)-22r questionnaire. One segment above fusion the anterior disk height significantly decreased on standing radiographs. Two segments above the fusion, the anterior disk height significantly decreased on supine as well as on standing radiographs. The largest reduction was found two segments above the fusion where the disk height was reduced from 33 to 28% of anterior vertebral height between the measurements at mean 8 years and mean 33 years after surgery. There were no statistically significant decreases in posterior disk heights in any measurement. The disk height showed a moderate negative correlation to PT. There was no correlation between disk height reduction and SRS-22r outcome. In our long-term follow-up of fusion without attempted reduction for high-grade spondylolisthesis in young patients, we found only a minor but statistically significant reduction in adjacent segment disk height which had no apparent impact on clinical outcome. Level IV.

Observational study.To evaluate self-image after in situ fusion for high-grade isthmic spondylolisthesis.Certain clinical findings such as short trunk or waistline skin folds are often seen in high-grade spondylolisthesis. Since treatment with spinal fusion in situ does not address appearance, self-image and also health-related quality of life might be negatively affected in the short-term as well as the long-term perspective. This observational study evaluated health-related quality of life outcome including self-image three decades after in situ fusion for high-grade isthmic spondylolisthesis in relation to healthy controls.Thirty-eight of 39 consecutive patients, fused in situ for high-grade isthmic spondylolisthesis at a young age, completed the Scoliosis Research Society (SRS)-22r questionnaire 28-41 years after surgery. The results were compared with the results of an age- and gender-matched control group.We found that the SRS-22r self-image domain scores were statistically significantly lower in patients than in controls whereas the pain and mental health scores were similar in patients and controls. Also, the SRS-22r function domain scores were statistically significantly lower in patients but the difference in means was small. We found no correlation between severity of slip and SRS-22r outcome.In situ fusion for high-grade isthmic spondylolisthesis is a safe treatment option in the long term from a function and pain perspective, but the results of our study suggest that self-image is negatively affected long into adult life.Level IV.

The current literature on clinical appearance after surgery for high-grade spondylolisthesis is inconclusive. The few long-term comparative studies on surgical reduction versus in situ fusion report contradictory findings concerning appearance-related issues. The purpose of the current study was to evaluate and quantify clinical appearance three decades after in situ fusion for high-grade isthmic spondylolisthesis. The Scoliosis Research Society (SRS)-22r questionnaire, digital photographs and standing lateral radiographs were used to evaluate clinical appearance for 22 patients three decades after in situ fusion for high-grade spondylolisthesis. The appearance was assessed by two spine surgeons, by the patient themselves, and by quantification of cosmesis relevant radiographic variables including pelvic parameters and sagittal balance. The surgeon inter- and intraobserver reliability of the photographic evaluation of the trunk deformity was at most moderate (Cohen’s kappa 0.5). Correlation analysis revealed at most medium correlation between radiographic outcome and self-rated (SRS-22r) self-image (Spearman’s rank correlation coefficient 0.3). The agreement between patient and surgeon-rated trunk appearance was poor (Cohen’s kappa 0.2). Photographic evaluation of the trunk deformity in high-grade spondylolisthesis is unreliable. There were only weak correlations between patient self-assessed trunk appearance and radiographic parameters. The results reflect the pronounced subjectivity of cosmesis, and that the trunk deformity in high-grade spondylolisthesis is not easily observed. IV.

Lumbar spinal stenosis (LSS) can be surgically treated, with variable outcome. Studies have linked socioeconomic factors to outcome, but no nation-wide studies have been performed. This register-based study, including all patients surgically treated for LSS during 2008–2012 in Sweden, aimed to determine predictive factors for the outcome of surgery. Clinical and socioeconomic factors with impact on outcome in LSS surgery were identified in several high-coverage registers, e.g., the national quality registry for spine surgery (Swespine, FU-rate 70–90%). Multivariate regression analyses were conducted to assess their effect on outcome. Two patient-reported outcome measures, Global Assessment of leg pain (GA) and the Oswestry Disability Index (ODI), as well as length of sick leave after surgery were analyzed. Clinical and socioeconomic factors significantly affected health outcome (both GA and ODI). Some predictors of a good outcome (ODI) were: being born in the EU, reporting no back pain at baseline, a high disposable income and a high educational level. Some factors predicting a worse outcome were previous surgery, having had back pain more than 2 years, having comorbidities, being a smoker, being on social welfare and being unemployed. The study highlights the relevance of adding socioeconomic factors to clinical factors for analysis of patient-reported outcomes, although the causal pathway of most predictors’ impact is unknown. These findings should be further investigated in the perspective of treatment selection for individual LSS patients. The study also presents a foundation of case mix algorithms for predicting outcome of surgery for LSS. These slides can be retrieved under Electronic Supplementary Material.

OBJECTIVEThe clinical outcomes and complications of patients who underwent pedicle subtraction osteotomy (PSO) for various diagnoses were compared. More specifically, the purpose was to identify if outcomes differed between patients with flat-back syndrome after lumbar fusion (FBS-LF) versus patients who underwent surgery for adult spinal deformity (ASD).METHODSA retrospective analysis of 104 patients who underwent a PSO for sagittal plane imbalance was performed. There were 28 patients with FBS-LF and 76 patients with various forms of ASD. Outcome was measured using visual analog scale (VAS)-back, VAS-leg, Oswestry Disability Index (ODI) (range 0–100 for all scales), and EQ-5D scores (range 0–1). Patients also rated their global outcomes as much better, better, unchanged, or worse at follow-up. The minimum follow-up was 1 year (range 1–4 years). Clinical outcomes and complications were compared between the 2 groups of patients.RESULTSThe most common level of PSO was L-3 and L-2; 100 single and 4 double PSOs were performed. The average local correction by PSO itself was 27.2°. The sagittal vertical axis (SVA) improved from a mean preoperative value of 74 ± 23 mm to 49 ± 20 mm at the final follow-up. The VAS-back, ODI, and EQ-5D scores improved significantly for the entire group by 33, 16, and 0.31 points, respectively. In total, 57% of patients reported that they were “much better” or “better” than before surgery. Preoperatively, as well as postoperatively, the FBS-LF patients reported significantly worse VAS scores. According to VAS-back results, the ASD group improved by 34 points compared with 29 points in FBS-LF patients. ODI scores were similar between the 2 groups preoperatively but improved significantly more in the ASD group (18 points) compared with the FBS-LF group (13 points). The EQ-5D scores improved from 0.07 to 0.35 in FBS-LF patients, and from 0.21 to 0.56 on average in ASD patients. Similarly, a “much better” or “better” outcome compared with before surgery was reported by 72% of patients in the ASD group compared with 24% of patients in the FBS-LF group (p < 0.001). The overall reoperation rate was 31%: 46% of patients in the FBS-LF group compared with 25% of patients in the ASD group. There were 19 (18%) dural tears, 14 (13.5%) surgical site infections, 12 (11.5%) instances of pseudarthrosis, 15 (14%) proximal junctional failures, and 2 distal junctional failures. The 12 (11%) neurological complications were dominated by partial weakness of hip flexion and knee extension, and all but 2 of these were temporary.CONCLUSIONSPSO is a safe and effective method for correcting sagittal plane imbalance due to multiple etiologies. The authors found patient satisfaction to be high, and health-related quality of life was greatly improved by the procedure in patients with ASD. In contrast, in FBS-LF patients, a suboptimal outcome was observed and the cautious use of PSO seems warranted in this subset of patients.

INTRODUCTION: Symptoms of dizziness or imbalance are often present in individuals with a variety of neck-disorders. The aims of this study were to determine the prevalence of patient-reported balance problems and dizziness 10-13 years after surgery for cervical degenerative disc disease; evaluate associations with neck pain and health-related quality of life; and investigate how these individuals described dizziness. MATERIAL AND METHODS: Sixty-eight individuals, 10 years or more after anterior cervical decompression and fusion surgery, who previously participated in a randomized controlled trial were included. Participants completed questionnaires including ratings of dizziness and balance problems, the Dizziness Handicap Inventory, and an open-ended question regarding their experience of dizziness. Secondary outcomes were neck pain and quality of life. RESULTS: Seventy-two percent experienced occasional or daily symptoms of unsteadiness and/or dizziness. Intensity ratings for dizziness during movement and for balance problems were similar and rather low, but had an impact on quality of life. Ratings of dizziness at rest were even lower. Dizziness ratings were associated with neck pain. Strenuous activities were related to dizziness and dizziness was primarily described as intermittent and non-rotatory. CONCLUSIONS: Dizziness or balance problems in the long-term after surgery for cervical degenerative disc disease are common and have an impact on daily life. Ratings of problem frequency and intensity were usually low. Dizziness and balance problems may affect quality of life. Patients' descriptions of these problems are in line with common symptoms of cervicogenic dizziness.

Background This case series of consecutive patients evaluated sagittal balance and health-related quality of life (HRQoL) 3 decades after in situ arthrodesis for high-grade isthmic spondylolisthesis. Methods Global sagittal balance, pelvic parameters, and compensatory mechanisms were evaluated on standing lateral radiographs of the spine and pelvis for 28 of 39 consecutive patients, 28 to 41 years after in situ arthrodesis for high-grade L5 to S1 spondylolisthesis. The mean age at surgery was 14 years (range, 9 to 24 years), and the mean age at the time of follow-up was 48 years (range, 39 to 59 years). A subset of the radiographic parameters was compared with the corresponding data from an 8-year follow-up examination of the same patients. HRQoL was evaluated with the Scoliosis Research Society (SRS)-22r questionnaire. Results We found that 3 of the 28 patients had a global sagittal imbalance (T1 spinopelvic inclination of >0°). Signs of compensatory mechanisms, such as reduced thoracic kyphosis and pelvic retroversion, were frequent. There was a significant decrease in sacral slope compared with 8-year follow-up data (p = 0.01). The median SRS-22r subscore was on the same level as Swedish normative data. We found no association between radiographic parameters and SRS-22r outcome. Conclusions Three decades after in situ arthrodesis for high-grade spondylolisthesis, radiographic signs of noncompensated sagittal imbalance were observed in only a few individuals. The patients had normal SRS-22r scores. There was no association between any radiographic parameter and SRS-22r outcome. The findings are relevant in the controversial discussion on whether to perform a reduction procedure to treat high-grade spondylolisthesis. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Study Design Randomized controlled trial. Objective Despite a large number of publications of outcomes after spinal fusion surgery, there is still no consensus on the efficacy of the several different fusion methods. The aim of this study was to determine whether transforaminal lumbar interbody fusion (TLIF) results in an improved clinical outcome compared with uninstrumented posterolateral fusion (PLF) in the surgical treatment for chronic low back pain. Methods This study included 135 patients with degenerative disk disease ( n = 96) or postdiskectomy syndrome ( n = 39). Inclusion criteria were at least 1 year of back pain with or without leg pain in patients aged 20 to 65 with one- or two-level disease. Exclusion criteria were sequestration of disk hernia, psychosocial instability, isthmic spondylolisthesis, drug abuse, and previous spine surgery other than diskectomy. Pain was assessed by visual analog scale (pain index). Functional disability was quantified by the disability rating index and Oswestry Disability Index. The global outcome was assessed by the patient and classified as much better, better, unchanged, or worse. The patients were randomized to conventional uninstrumented PLF ( n = 67) or TLIF ( n = 68). PLF was performed in a standardized fashion using autograft. TLIF was performed with pedicle titanium screw fixation and a porous tantalum interbody spacer with interbody and posterolateral autograft. The clinical outcome measurements were obtained preoperatively and at 12 and 24 months postoperatively. The 2-year follow-up rate was 98%. Results The two treatment groups improved significantly from preoperatively to 2 years’ follow-up. At final follow-up, the results in the TLIF group were significantly superior to those in the PLF group in pain index (2.0 versus 3.9, p = 0.007) and in disability rating index (22 versus 36, p = 0.003). The Oswestry Disability Index was better in the TLIF group (20 versus 28, p = 0.110, not significant). The global assessment was clearly superior in the TLIF group: 63% of patients scored “much better” in the TLIF group as compared with 48% in the PLF group ( p = 0.017). Conclusions The results of the current study support the use of TLIF rather than uninstrumented PLF in the surgical treatment of the degenerative lumbar spine. The less optimal outcome after uninstrumented PLF may be explained by the much higher reoperation rate.

The surgical treatment of spinal metastases is evolving. The major problem is the selection of patients who may benefit from surgical treatment. One of the criteria is an expected survival of at least 3 months. A prediction model has been previously developed. The present study has been performed in order to validate externally the model and to demonstrate that this model can be generalized to other institutions and other countries than the Netherlands. Data of 356 patients from five centers in Germany, Spain, Sweden, and the Netherlands who were treated for metastatic epidural spinal cord compression were collected. Hazard ratios in the test population corresponded with those of the developmental population. However, the observed and the expected survival were different. Analysis revealed that the baseline hazard function was significantly different. This tempted us to combine the data and develop a new prediction model. Estimating iteratively, a baseline hazard was composed. An adapted prediction model is presented. External validation of a prediction model revealed a difference in expected survival, although the relative contribution of the specific hazard ratios was the same as in the developmental population. This study emphasized the need to check the baseline hazard function in external validation. A new model has been developed using an estimated baseline hazard

Background context The posterior ligamentous complex (PLC) is thought to contribute significantly to the stability of thoracolumbar spine. Obvious translation or dislocation of an interspace clearly denotes injury to the PLC. A recent survey of the Spine Trauma Study Group indicated that plain radiographic findings, if present, are most helpful in determining PLC injury. However, confusion exists when plain radiography shows injury to the anterior spinal column without significant kyphosis or widening of the posterior interspinous space. Purpose The objective of this study is to identify imaging parameters that may suggest a disruption of the posterior ligamentous complex of the thoracolumbar spine in the setting of normal-appearing plain radiographs. This study was performed, in part, as a pilot study to determine critical imaging parameters to be included in a future prospective, randomized, multicenter study. Study design/setting Survey analysis of the Spine Trauma Study Group. Patient sample None. Outcome measures Compilation and statistical analysis of survey results. Methods Based on a systematic review of the English literature from 1949 to present, we identified a series of traits not found on plain X-rays that were consistent with PLC injury. This included five imaging findings on either computed tomography (CT) scans or magnetic resonance imaging (MRI) and several physical examination features. These items were placed on a survey and sent to the members of the Spine Trauma Study Group. They were asked to rank the items from most important to least important in representing an injury to the PLC in the setting of normal-appearing plain radiographs. Results Thirty-three of 47 surveys were returned for final analysis. Thirty-nine percent (13/33) of the members ranked “disrupted PLC components (i.e., interspinous ligament, supraspinous ligament, ligamentum flavum) on T1 sagittal MRI” as the most important factor in determining disruption of PLC. When analyzed with a point-weighted system, “diastasis of the facet joints on CT” received the most points, indicating that this category was ranked high by the majority of the members of the group. The members were also given freedom to add other criteria that they believed were important in determining PLC integrity in the setting of normal-appearing plain radiograph. Of the other criteria suggested, one included a physical finding and the other a variant of MR sequencing. Conclusions In a setting of normal-appearing plain radiographs, PLC injury as displayed on T1-weighted MRI and diastasis of the facet joints on CT scan seem to be the most popular determinants of probable PLC injury among members of the Spine Trauma Study Group. Between MRI and CT scan, most members feel that various characteristics on MRI studies were more helpful.

Study design Prospective, blinded validation study of an objective, quantitative measure to assess maximum canal compromise (MCC) and maximum spinal cord compression (MSCC) in individuals with acute cervical spinal cord injury (SCI). Objective To examine the intraobserver and interobserver reliability of MCC and MSCC in individuals with acute traumatic cervical SCI. Summary of background data To date, few quantitative reliable radiologic methods for assessing the extent of spinal cord compression in the setting of acute SCI have been reported. MCC and MSCC, as assessed on mid-sagittal CT and T2-weighted MR images, respectively, appear to have potential clinical and prognostic value. To date, the validation of these assessment tools has been limited to a small number of observers at a single institution. However, to date no study has focused on the reliability of these radiologic parameters among a large cohort of spine surgeons from North America and abroad. This type of validation is critical to allow the broader use of these outcome measures in research studies and in clinical practice. Methods Mid-sagittal MRI and CT images of cervical spine were selected from 10 individuals with acute traumatic cervical SCI. A total of 28 spine surgeons independently estimated CT MCC, T1-weighted MRI MCC, and T2-weighted MRI MSCC on two occasions using a calibrated ruler. In the first round of measurements, the observers estimated the radiologic parameters using only written instructions. The second measurement set was obtained after an interactive teaching session on the methodology. The order of the images was altered for the second set of measurements. Results Analysis using parametric and nonparametric statistics indicated high intraobserver reliability for CT MCC, T1-weighted MRI MCC, and T2-weighted MSCC with interclass correlation coefficients (ICCs) of 0.92, 0.95, and 0.97, respectively. The interobserver reliability for all three radiologic parameters was considered moderate with ICCs ranging from 0.35 to 0.56. Conclusion Our results indicate that the intraobserver reliability for the MCC and MSCC was high. Although the interobserver reliability for all three radiologic parameters in the present study was below 0.75, the observed differences were small and largely accounted for by the limitations in the precision of the calibrated ruler. For cases with minimal cord compression, the measurement of canal stenosis (MCC) proved more accurate. In contrast, in cases with severe cord compression, the assessment of MSCC was more accurate. It is anticipated that the use of digital imaging technologies will further enhance the precision of these outcome measures.

Background Today there is some evidence-based medicine support for a positive short-term treatment effect of fusion in chronic low back pain in spondylolisthesis and in nonspecific degenerative lumbar spine disorders. The long-term effect is, however, unknown. Purpose To determine the long-term outcome of lumbar fusion in adult isthmic spondylolisthesis. Study design Prospective, randomized controlled study comparing a 1-year exercise program with instrumented and non-instrumented posterolateral fusion with average long-term follow-up of 9 years (range, 5–13). Patient sample 111 patients aged 18 to 55 years with adult lumbar isthmic spondylolisthesis at L5 or L4 level of all degrees, and at least 1-year's duration of severe lumbar pain with or without sciatica. Outcome measures Pain and functional disability was quantified by pain (VAS), the Disability Rating Index (DRI), the Oswestry Disability Index (ODI) work status, and global assessment of outcome by the patient into much better, better, unchanged or worse. Quality of life was assessed by the SF-36. Methods The patients were randomly allocated to treatment with 1) a 1-year exercise program (n=34), 2) posterolateral fusion without pedicle screw instrumentation (n=37), or 3) posterolateral fusion with pedicle screw instrumentation (n=40). Long-term follow-up was obtained in 101 (91%) patients. Nine patients in the exercise group were eventually operated on. Results Longitudinal analysis: At long-term follow-up pain and functional disability were significantly better than before treatment in both surgical groups. No significant differences were observed between instrumented and non-instrumented patients in any variable studied. In the exercise group the pain was significantly reduced but not the functional disability. Compared with the 2-year follow-up a significant increase in functional disability was observed, as measured by the DRI, but not the ODI, in the surgical group at long term. In the exercise group no significant changes were observed between the 2-year and the long-term follow-up. Cross-sectional analysis: Between the surgical and conservative group no significant differences were observed in any outcome measurement at long-term follow-up except for global assessment, which was significantly better for surgical patients. Of surgical patients 76% classified the overall outcome as much better or better compared with 50% of conservatively treated patients (p=0.015). Quality of life as estimated by the SF-36 at long term was not different between treatment groups in any of the eight domains studied but was considerably lower than for the normal population. Conclusions Posterolateral fusion in adult lumbar isthmic spondylolisthesis results ina modestly improved long-term outcome compared with a 1-year exercise program. Although the results show that some of the previously reported short-term improvement is lost at long term, patients with fusion still classify their global outcome as clearly better than conservatively treated patients. Furthermore, because the long-term outcome of the patients conservatively treated most likely reflects the natural course, one can also conclude that no considerable spontaneous improvement should be expected over time in adult patients with symptomatic isthmic spondylolisthesis. Substantial pain, functional disability and a reduced quality of life will in most patients most likely remain unaltered over many years.

STUDY DESIGN A prospective randomized study was conducted. OBJECTIVE To determine whether the use of a cervical carbon fiber intervertebral fusion cage improves the outcome of anterior cervical decompression and fusion, as compared with the Cloward procedure using autograft. SUMMARY OF BACKGROUND DATA Despite the theoretical advantages of using intervertebral cages, including reduced donor site morbidity and prevention of graft collapse, an improved clinical outcome has not yet been documented. METHODS For this study, 103 patients were randomized to anterior cervical decompression and fusion with a carbon fiber intervertebral fusion cage (n = 52) or the Cloward procedure (n = 51). An independent observer quantified pain and functional disability. Fusion rate, segmental kyphosis, and disc height were assessed by radiographs. RESULTS During a mean follow-up period of 36 months (range, 24-72 months) for 89 patients (86%), the pain and disability were similar for both treatments. Postoperative donor site pain was significantly less in the carbon fiber intervertebral fusion cage group. The fusion rate was 86% in the Cloward procedure group and 62% in the carbon fiber intervertebral fusion cage group (P < 0.05). In the latter group, patients with pseudarthrosis reported more severe pain than fused patients (51 and 33 visual analog scores, respectively), but the difference was not significant. The segmental kyphosis was less and the disc height increased in the carbon fiber intervertebral fusion cage group, as compared with the Cloward procedure group. Disc height was not correlated with outcome. Segmental kyphosis showed a weak (r = -0.3) but significant (P < 0.05) correlation with improvement of the Cervical Spine Functional Score, but not with other outcome variables. CONCLUSIONS Except for reduced donor site pain, the clinical outcome for the carbon fiber intervertebral fusion cage is the same as for the Cloward procedure. Use of the cage results in a more lordotic alignment and an increased disc height, but in a higher pseudarthrosis rate than use of the Cloward procedure.

The segmental effect of Cotrel-Dubousset instrumentation (CDI) on the spine and thoracic cage was investigated in 38 patients with adolescent idiopathic scoliosis by preoperative and postoperative postero-anterior and lateral radiographs and computed tomography from T1 to S1. Mean Cobb angle decreased by 67%. The T5-T12 kyphosis in the hypokyphotic patients increased on average by 8.4 degrees (P < 0.001). Average preoperative as well as postoperative maximal vertebral rotation was located at the apex level, and was reduced from 19.0 degrees to 14.3 degrees (P < 0.001). All vertebrae between the upper and lower instrumented vertebrae were significantly derotated. Average derotation for the apical zone was 4.8 degrees (P < 0.001), for the upper instrumented zone it was 2.5 degrees (P < 0.01), and for the lower instrumented zone it was 2.6 degrees (P < 0.01). Vertebral derotation was significantly higher in the apical zone than in the upper and lower instrumented zones. The apical rib hump index (RHi) decreased by 38% (P < 0.001) and the cumulative RHi for the five apical levels decreased by 34% (P < 0.001). The RHi for the two levels above and below the instrumentation each decreased by 20% (n.s.). No significant increase in sagittal or transverse rib cage diameter at any level was observed. The translation in the coronal plane of the apical vertebra of major right thoracic curves improved significantly (P < 0.001). The preoperative flexibility index of the major curve correlated positively (r = 0.47) with derotation at the apex level (P < 0.01). However, no correlation was found between flexibility index and reduction of RHi at the apex level. Vertebral derotation did not correlate with reduction in RHi at any level. The study shows that CDI results in a postoperative three-dimensional improvement of the spine and a limited improvement of the thoracic cage, with no tendency towards a worsened deformity at any level within or outside the instrumentation.

The rotation and structural changes of the apex vertebra in the horizontal plane as well as of the thoracic cage deformity were quantified by measurements on computed tomography (CT) scans from patients with right convex thoracic idiopathic scoliosis (IS). The CT scans were obtained from 12 patients with moderate scoliosis (mean Cobb angle 25.8 degrees, r 13 degrees-30 degrees) and from 33 with severe scoliosis (mean Cobb angle 46.2 degrees, r 35 degrees-71 degrees). In addition, CT scans of thoracic vertebrae from 15 patients without scoliosis were used as reference material. Ten of the scoliotic cases had had Cotrel-Dubousset instrumentation (CDI) and posterior fusion and had entered a longitudinal study on the effect of operative correction on the re-modelling of the apical vertebra. An increasingly asymmetrical vertebral body, transverse process angle, pedicle width and canal width were found in the groups with scoliosis as compared with the reference material. Vertebral rotation and rib hump index were significantly larger in patients with early and advanced scoliosis than in normal subjects. The modelling angle of the vertebral body, the transverse process angle index and the vertebral rotation in relation to the middle axis of the thoracic cage were significantly greater in patients with severe than with moderate scoliosis. The results of this longitudinal study suggest that the structural changes of the apical vertebra regress 2 years or more after CD instrumentation.

We investigated the 3-dimensional effect of electrostimulation of the latissimus dorsi, the erector spinae and the intercostal muscles on spinal configuration in 16 New Zealand white rabbits. Electrostimulation on the right side of the spine resulted in a left convex, hypokyphotic curve and vertebral body rotation towards the convexity of the curve in all rabbits. The Cobb angle in the coronal plane increased with stimulation of each of the muscles examined. The kyphosis decreased with stimulation of the latissimus dorsi and the erector spinae. The vertebral rotation increased with stimulation of all muscles. Stimulation of the tested muscles resulted in the simultaneous occurrence of a 3-dimensional spinal deformity with the characteristics of idiopathic scoliosis.

In order to investigate the development of the vertebral axial rotation in patients with early scoliosis, the vertebral rotation angle (VRA) was quantified on the basis of 132 anteroposterior radiographs obtained from patients with diagnosed or suspected scoliosis. The rotation was measured in the apical vertebra and in the two suprajacent and two subjacent vertebrae. The radiographic material was divided into a control reference group and three scoliotic groups with varying Cobb angle from 4 degrees up to 30 degrees. In the reference group a slight vertebral rotation was significantly more often seen to the right. In the scoliotic groups, the rotation was most pronounced in the apical segments. The mean VRA toward the convex side was significantly increased in the vertebrae just suprajacent to the apex in curves with a Cobb angle of 8 degrees-15 degrees and in the cranial four vertebrae in curves with a Cobb angle of 16 degrees-30 degrees. Atypical vertebral rotation to the opposite side of the major curve was observed in 12.8% of the cases. There was a significant positive correlation between the VRA and the Cobb angle. These results show that a slight VRA to the right is a common feature in the normal spine, and that the VRA increases with progressive lateral deviation of the spine. It is concluded that the coronal plane deformity in early idiopathic scoliosis is accompanied and probably coupled to vertebral rotation in the horizontal plane.

A prospective study on predictive factors for the outcome of 164 patients with adult isthmic spondylolisthesis operated on with fusion. In view of the need to better select patients for fusion, we investigated the use of the pain drawing (PD) and other potential factors for predicting the outcome of fusion. Results on predictive factors of outcome after spinal fusion have been contradictory and large, well-defined, patient samples with adequate observation times are lacking. Questionnaires including possible predictive factors and PDs were obtained before surgery. Degree and level of slip were documented. Outcome was quantified by measurement of pain (VAS), Disability Rating Index, the Oswestry Disability Index, and global assessment by the patient into "much better," "better," "unchanged," or "worse." The 2-year follow-up rate was 160 of 164 (98%). In the total sample 49% of patients were much better, 25% better, 14% unchanged, and 12% worse. The following preoperative factors correlated to a worse outcome in the univariate analysis: not working, no regular exercise, female gender, shortness in stature, and a nonorganic PD. The multivariate regression analysis showed that work status was the main determinant of outcome. Gender and exercise had less but significant impact (P = 0.004 and 0.02, respectively). In the multivariate regression analysis the PD was not a significant predictor (P = 0.06). The present study shows that patients working before surgery have a more favorable outcome. Also male gender and regular exercise are indicators of a better outcome after fusion. Female patients not working, not exercising or, if these factors are not known, with nonorganic PDs, should be informed about their suboptimal chances of an excellent outcome after fusion.

The existence and importance of an accelerated adjacent segment disc degeneration (ASD) after lumbar fusion have previously not been demonstrated by RCTs. The objectives of this study were, to determine whether lumbar fusion in the long term accelerates degenerative changes in the adjacent disc and whether this affects the outcome, by using a prospective randomised design. A total of 111 patients, aged 18-55, with isthmic spondylolisthesis were randomised to exercise (EX, n = 34) or posterolateral fusion (PLF, n = 77), with (n = 37) or without pedicle screw instrumentation (n = 40). The minimum 10 years FU rate was 72%, with a mean FU time of 12.6 years (range 10-17 years). Three radiographic methods of ASD quantification were used, i.e. two digital radiographic measurement methods and the semi quantitative UCLA grading scale. One digital measurement method showed a mean disc height reduction by 2% in the EX group and by 15% in the PLF group (p = 0.0016), and the other showed 0.5 mm more disc height reduction in the PLF compared to the Ex group (ns). The UCLA grading scale showed normal discs in 100% of patients in the EX group, compared to 62% in the PLF group (p = 0.026). There were no significant differences between instrumented and non-instrumented patients. In patients with laminectomy we found a significantly higher incidence of ASD compared to non laminectomised patients (22/47 vs. 2/16 respectively, p = 0.015). In the longitudinal analysis, the posterior and anterior disc heights were significantly reduced in the PLF group, whereas in the EX group only the posterior disc height was significantly reduced. Except for global outcome, which was significantly better for patients without ASD, the clinical outcome was not statistically different in patients with and without ASD. In conclusion, the long-term RCT shows that fusion accelerates degenerative changes at the adjacent level compared with natural history. The study suggests that not only fusion, but also laminectomy may be of pathogenetic importance. The clinical importance of ASD seems limited, with only the more severe forms affecting the outcome.

STUDY DESIGN: A prospective study with historical controls. OBJECTIVE: To compare the outcome of posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF) in adult isthmic spondylolisthesis. SUMMARY OF BACKGROUND DATA: On theoretical grounds, PLIF has been suggested to result in an improved outcome compared with PLF. Data to support this view, however, are lacking. METHODS: A total of 86 patients (age range, 18-55 years) with adult isthmic spondylolisthesis were operated on with PLIF. The comparison group consisted of 77 patients operated on with PLF with iliac bone autograft, 40 with and 37 without pedicle fixation. The 2 groups had similar socioeconomic, age and sex distribution, level of pain, and disability. Inclusion criteria and outcome measurements were identical in both groups. The PLIF group was operated on with autograft and carbon fiber ramps with pedicle fixation. Before surgery and at the 2-year follow-up, pain (VAS) and functional disability were quantified by the Disability Rating Index (DRI, 0-100) and the Oswestry Disability Index (ODI). The global outcome was assessed by the patient as much better, better, unchanged, or worse. RESULTS: The follow-up rate was 98% in the PLIF group and 97% in the PLF group. In PLIF patients, pain index improved from 66 to 35 (P < 0.0001) and the DRI from 47 to 30 (P < 0.01). The levels of pain and DRI were similar to that of the PLF group (pain 37, DRI 29, not significant), and the ODI was identical in both groups (25); 74% of the patients in both groups classified the results as much better or better. CONCLUSION: Type of fusion, PLIF or PLF, does not affect the 2-year outcome of surgical treatment of adult isthmic spondylolisthesis. Despite the theoretical advantages of PLIF, no improvement on patient outcome compared with posterolateral fusion could be demonstrated, questioning the need of anterior support in short lumbar fusions.

In a prospective randomised study with a 2-year follow-up, 103 patients were randomised to anterior cervical decompression and fusion (ACDF) with a cervical carbon-fibre intervertebral fusion cage (CIFC) or the Cloward procedure (CP). The purpose of the present study was to report predictors for fusion and also to investigate the importance of radiological variables for the clinical outcome. Gender, age, smoking habits, disc height, segmental kyphosis and type of surgical procedure were used as independent (before surgery) variables in a multiple regression model. Male gender, one-level surgery and CP treatment were significant predictors of fusion and explained 14% of the variability of fusion status at follow-up. Number of levels operated on, however, did not influence the clinical outcome. Fifty-two per cent of the women and 17% of the men in the CIFC group, and 25% of the women and 8% of the men in the CP group, had pseudarthrosis. Although patients with a healed fusion had significantly less pain intensity than patients with pseudarthrosis, radiological variables explained only 4% of the variability of pain at follow-up. Apart from a significant correlation between preoperative kyphosis and neck disability index at follow-up, no significant correlation between either postoperative kyphosis or preoperative or postoperative disc height and clinical outcome was found. Neither degree of segmental kyphosis nor disc height was different between patients with healed fusion and pseudarthrosis. One can conclude that male gender and type of surgery were significant predictors for a healed fusion and that pseudarthrosis affected outcome. In contrast to the commonly held view based mainly on theoretical considerations, no effect on clinical outcome could be demonstrated for segmental kyphosis and disc height at follow-up. Overall, the study shows that the importance of radiological factors as predictors for fusion as well as clinical outcome is limited.

In a prospective study, 103 patients were randomised to anterior cervical decompression and fusion (ACDF) with a cervical carbon-fibre intervertebral fusion cage or the Cloward procedure. Preoperative background variables, active range of neck motion, handgrip strength, radiological evaluation and subjective variables were used in a multiple regression model to find the strongest predictors of postoperative outcome as measured by current pain intensity and the Neck Disability Index (NDI). Male sex, greater kyphosis at the level operated on, non-smoking, a greater neck mobility in right rotation, low disability on NDI, and older age were predictors of pain reduction and explained 30% of current pain intensity at follow-up. Higher educational level, non-smoking, greater kyphosis at the level operated on, a greater flexion mobility, greater right handgrip strength and lower current pain intensity were predictors of improvement, and explained 28% of the postoperative outcome on NDI. The most important predictor for postoperative pain intensity was the magnitude of the preoperative kyphosis. Preoperative pain intensity was the most important predictor for improved NDI. At follow-up about 70% of the patients still had deficit based on current pain intensity and NDI, and 44% had remaining dysfunction based on Odom's criteria. In conclusion, the multivariate analysis shows that male sex, non-smoking, greater segmental kyphosis and a low pain and disability level are preoperative predictors of a good outcome in ACDF. In addition, the study suggests the importance of other predictive variables than those studied for the outcome of ACDF.

The aim of the thesis was to investigate the reliability of the test procedure, and to obtain reference values for active range of motion (AROM) of the neck, neck-, and hand strength. Another aim was to perform a broad assessment of outcome in patients with cervical disc disease operated on by anterior cervical decompression and fusion (ACDF) and to identify predictive factors for a good outcome. For a broad assessment it is important to have reliable objective and subjective variables, and reference values obtained in healthy people.Three studies concern reliability and reference values for neck AROM, neck strength, and hand strength of healthy individuals. One study concerns the outcome of 34 consecutively included patients six months and one year after ACDF, and any remaining deficits afterwards. One study is a prospective randomised study of 103 patients concerning prognostic factors (mean follow-up 19 months, SD 6, range 12-24 months) for a good outcome of ACDF, and any remaining deficits afterwards.The intra-, and inter-tester reliability of neck AROM, neck strength, and hand strength obtained from 30-32 healthy volunteers were considered substantial to almost perfect (ICC-values 0.61-0.98) and can be used for comparisons between or within groups. The reference values obtained in 101 asymptomatic men and women aged 25-64 years showed that age was the most important factor to take into consideration when measuring neck AROM, and gender was most important for neck and hand strength measurements. The patients showed benefits from ACDF at the one-year follow-up in neck strength in lateral flexion, neck muscle endurance in flexion, pain, numbness, ADL, Neck Disability Index (NDI), sick leave, change in general health, and symptom satisfaction. Except for a deterioration in general health there were no significant differences between the six-month and the one-year followup. The most important predictor for low postoperative pain intensity was greater preoperative kyphosis.The predictive value of segmental kyphosis is noteworthy and of potential clinical interest. Low preoperative pain intensity was the most important predictor for improved NDI. Non-smoking males with a greater segmental kyphosis at the level of surgical intervention, with less severe pain experience and better initial function, had the best prognosis for a successful outcome of ACDF. Although the patients experienced benefits from surgery in many of the variables, a large number still had remaining deficits. These studies support the need for improvements in the selection for and the treatment techniques in both surgery and physiotherapy in degenerative cervical disorders.

Study design A prospective randomized study was performed. Objective To determine whether transpedicular fixation improves the outcome of posterolateral fusion in patients with adult isthmic spondylolisthesis. Summary of background data The use of transpedicular fixation remains controversial. Both a positive effect and no effect from additional transpedicular fixation have been reported. Methods In this study, 77 patients randomly underwent posterolateral fusion with (n = 37) or without (n = 40) transpedicular fixation. The inclusion criteria were lumbar isthmic spondylolisthesis of any grade, at least 1 year of low back pain or sciatica, and severely restricted functional ability in individuals 18 to 55 years of age. Results The follow-up rate was 94%. At a 2-year follow-up assessment, the level of pain and functional disability were strikingly similar in the two groups, and there was no significant difference in fusion rate. Conclusions Lumbar posterolateral fusion performed in situ for adult isthmic spondylolisthesis relieves pain and improves function. The use of supplementary transpedicular instrumentation does not add to the fusion rate or improve the clinical outcome.

STUDY DESIGN: A prospective randomized study was performed. OBJECTIVE: To determine whether posterolateral fusion in patients with adult isthmic spondylolisthesis results in an improved outcome compared with an exercise program. SUMMARY OF BACKGROUND DATA: In spondylolisthesis, satisfactory results have been reported with both surgical and conservative management. The evidence for treatment efficacy, however, is weak because prospective randomized studies are lacking. METHODS: In this study, 111 patients were randomly allocated to an exercise program (n = 34) or posterolateral fusion with or without transpedicular fixation (n = 77). The inclusion criteria were lumbar isthmic spondylolisthesis of any grade, at least 1 year of low back pain or sciatica, and a severely restricted functional ability in individuals 18 to 55 years of age. Pain and functional disability were quantified before treatment and at 1- and 2-year follow-up assessments by visual analog scales (VAS). RESULTS: The 2-year follow-up rate was 93%. The functional outcome, as assessed by the Disability Rating Index and the pain reduction, was better in the surgically treated group than in the exercise group at both the 1- and 2-year follow-up assessments (P < 0.01). In the longitudinal analysis, the mean Disability Rating Index and pain improved in the surgical group (P < 0.0001). In the exercise group, the Disability Rating Index did not change at all, whereas the pain decreased slightly (P < 0.02). CONCLUSIONS: Surgical management of adult isthmic spondylolisthesis improves function and relieves pain more efficiently than an exercise program.

Study design A cross-sectional clinical study. Objectives To determine whether there are specific symptoms, signs, and functional disability associated with adult spondylolisthesis. Summary of background data In spite of the common occurrence of adult spondylolisthesis, the symptoms, signs, and disability associated with it have not been analyzed in a large, well-defined group of patients. Methods The symptoms, signs, and disability of 111 consecutive patients with adult spondylolisthesis, before randomized treatment with fusion or physiotherapy, were compared with those of 39 patients with nonspecific low back pain before lumbar fusion. The patients completed a questionnaire covering clinical history and symptoms and submitted a pain drawing. The signs were documented. Functional disability and pain were quantified by 12-function and 2-pain visual analog scales, respectively. Results Sixty-two percent of the patients reported low back pain as well as sciatica, 7% sciatica only, and 31% low back pain only. Specific signs were infrequent. A positive straight leg raising test result in 12% and an L5 sensory disturbance in 13% were the most common. The symptoms were similar in patients with spondylolisthesis and chronic low back pain, but the chronic low back pain group reported more functional disability. Patients with a nonorganic pain drawing (widespread, nonspecific pain) were more often blue collar workers; were more often and longer on sick leave; and reported reduced mental condition, sexual function, functional ability, and more pain than patients with an organic pain drawing (localized, specific pain). Conclusions The clinical pattern and functional disability in adult spondylolisthesis and in low back pain of nonspecific origin are similar. Sciatica in adult spondylolisthesis is typically not associated with a positive straight leg raising test result.

One CT-scan at the central part of the vertebral body of the apical vertebra of 32 patients with right convex thoracic idiopathic scoliosis and one CT-scan of either T8 or T9 of 22 normal subjects are included in this study. The position of the aorta in relation to the apical vertebra of the scoliotic patients and the corresponding vertebra of the normal subjects was determined at the horizontal plane. The mean lateral translation of the aorta in relation to the mid axis of the vertebral body increased from 19.7 +/- 4.3 mm in the normal group to 26.4 +/- 4.1 mm in the scoliotic group (p = 0.0001). In the normal group the aorta was located 41.7 +/- 8.6 mm in front of a perpendicular line to the mid axis of the vertebral body and in the scoliotic group this distance was reduced to 30.0 +/- 9.0 mm making the position of the aorta more posterior in the scoliotic group (p = 0.0001). This was in accordance with a decreased mean kyphosis-lordosis index from 0.53 +/- 0.06 in the normal group to 0.46 +/- 0.07 in the scoliotic group (p = 0.01). The position of the aorta, also expressed as the angle formed between the aorta and the vertebral body, the "aorto-vertebral angle", was increased from 24.4 degrees +/- 6.9 degrees in the normal group to 41.4 degrees +/- 8.4 degrees the scoliotic patients, (p = 0.0001). The aorto-vertebral angle did not change significantly with increasing Cobb angle (p = 0.26) but was positively correlated to the vertebral rotation (p = 0.0001). An estimation of the length of the intercostal arteries revealed a significantly greater R (right)/L (left) index in the scoliotic patients 1.18 +/- 0.11 than in the normal subjects 1.08 +/- 0.06 (p = 0.0003). It is concluded that the rotation and the anterior displacement of the vertebral body in scoliosis result in a deviation of the aorta along the left (concave) side of the vertebral body to a more posterior position relative to the vertebral body with a possible increased length of the intercostal artery on the right (convex) side.

Computed tomography (CT) scans are widely used for quantification of the morphology of the vertebral body and of the changes of the thoracic cage in the horizontal plane in scoliosis. So far, however, no method exists for precise quantification of the parameters of the posterior elements. We present a method for quantification on the basis of CT scans of different parameters of the morphology of both the vertebral body and posterior elements in the horizontal plane. The precision and accuracy of the method were estimated in a model study by CT scanning of a normal and a scoliotic vertebra in different, controlled, tilted positions. Moreover, in a clinical study CT scans of 19 thoracic vertebrae from non-scoliotic subjects and the apex vertebra from 40 scoliotic subjects were selected to test the applicability of the method to clinical studies. The intra- and interobserver variation of the measurements was analysed. The angle between the longitudinal axis of the vertebral body and that of the whole vertebra was used to evaluate the asymmetry of the vertebral body. The right to left pedicle width index, the right to left hemi-canal width index and the index of transverse process angles related to the axis of the vertebra were used to quantify the asymmetry of the posterior elements. The results indicate that, except for the pedicle width index, the variables under study were not significantly influenced by a 5° or 10° tilt ventrally, dorsally, or laterally of either the normal or the scoliotic vertebra. Hence, the method can be satisfactorily applied to longitudinal group comparisons. However, its use in longitudinal studies of individual patients is questionable.

The development of structural skeletal changes was evaluated on 132 anteroposterior radiographs of spines from three scoliotic groups with a Cobb angle of up to 30 degrees and a reference control group. Significant wedging of the vertebral bodies and disks at the coronal plane was registered in-curves with a Cobb angle of 4 degrees or more. Asymmetry of the rib-vertebra angle was found in curves with a Cobb angle of 8 degrees or more and was most pronounced in the cranial part of the curves. The early simultaneous occurrence of vertebral and disk wedging suggests the involvement of an extraspinal factor rather than growth disturbance of the vertebral body or of the disk in the early pathomechanism of scoliosis.

We studied the incidence of cervical and trochanteric hip fractures in Stockholm, Sweden from 1972 through 1981. The material, selected from a computerized medical information register, consisted of 11 812 cervical fractures and 8094 trochanteric fractures. The incidence did not change in the age group 50-74 years. In males 75 years of age and older, the incidence of both fracture types caused by moderate trauma increased annually by 5-6 per cent. In females 75 years and older, the incidence of trochanteric fractures caused by moderate trauma increased annually by 6 per cent, whereas the incidence of cervical fractures increased only marginally.

The incidence of diaphyseal femoral fracture in adults, aged 20 years and older, was determined in Stockholm County using hospital admission rates. The validity of the data was investigated by a study of the medical records of a sample of 277 cases and also by determining the incidence in a subpopulation of 139 cases using an alternative method. The incidence decreased from age 20 to middle age after which it increased into old age. The age-related increase was more pronounced in women and in fractures caused by moderate trauma. From 1972 to 1981, the incidence of diaphyseal femoral fracture caused by moderate trauma increased annually by 10 per cent in women aged 75 years and older.

We determined the trauma type of femoral neck and trochanteric fractures in men and women aged greater than or equal to 20 years in 19, 128 fractures reported to a computerized medical information register during 1972-1981. We found that the earlier known exponential increase of fracture incidence by age started in early adulthood rather than during middle age. An age-related increase was found for each type of injury as well, although the incidence of fractures resulting from severe trauma increased less than that of fractures associated with moderate trauma. The incidence of low-energy fractures in men as well as in women displayed a constant increase rate with age from young adulthood on, impugning the widely held belief that the menopause is a significant risk factor for fractures. The dominating risk factor for proximal femoral fracture in adults appears to be age, irrespective of the cause of injury, with a chronological decline in bone strength as the most likely cause of the exponential increase in the fracture incidence during adult life.

There has been controversy as to whether fluoride therapy increases the risk of fracture in the appendicular skeleton. In the present study we compared the incidence of hip fracture in four groups of osteoporotic women: 22 treated with placebo, 17 with fluoride and calcium, 18 treated with fluoride and calcitriol, and 21 with calcitriol alone. Four hip fractures occurred in 3 patients on fluoride and calcitriol, and two hip fractures occurred in 2 patients on fluoride and calcium. No hip fractures occurred in patients receiving either calcitriol alone or placebo. The difference in fracture rates for fluoride versus nonfluoride treatment is significant (p = 0.006). Moreover, the six hip fractures occurring in patients receiving fluoride during 72.3 patient years of treatment is 10 times higher than would be expected in normal women of the same age. The probability of observing six fractures in 2 years is extremely small (0.0003). In four of the hip fracture cases, the history suggested a spontaneous fracture. These findings suggest that fluoride treatment can increase the risk of hip fracture in osteoporotic women.

The risk of fracturing the proximal femur is high for individuals with metabolic bone disease or with low bone mass associated with advanced age. Incidences of 20,538 trochanteric and femoral neck fractures in adult Swedish men and women, from a computerized medical information register for all hospitals in Stockholm County, were analyzed for age- and sex-dependence. The rate of increase in the occurrence of fracture was nearly constant for both sexes, exponentially increasing with age for men over 20 years old and for women over 30 years old. The incidence of trochanteric and femoral neck fracture for men doubled every 7.8 and 7.0 years, respectively. The doubling rate of fracture incidence for premenopausal women, aged 30 to 49 years, did not significantly differ from that for postmenopausal women, aged 50 to 69 years. These findings suggest that age-associated factors common to both sexes provide the main risk for fracturing the proximal femur. Menopause does not pose a major risk.