How well do Radiologic Assessments of Truncal and Shoulder Balance Correlate With Cosmetic Assessment Indices in Lenke 1C Adolescent Idiopathic Scoliosis?

STUDY DESIGN: A correlation study. OBJECTIVE: The primary objective was to determine the correlation between radiologic and cosmetic indices of trunk and shoulder balance before and after scoliosis surgery in Lenke 1C adolescent idiopathic scoliosis and to determine whether postoperative trunk shift is affiliated with worsening of the patients' cosmesis. SUMMARY OF BACKGROUND DATA: Achieving a symmetrical appearance with truncal and shoulder balance is of prime importance to adolescent idiopathic scoliosis patients and their surgeons. However, surgeons prefer radiographic indices rather than measures of patients' clinical appearance. If radiographic indices are to be considered accurate depictions of the patient's cosmesis, radiologic and cosmetic indices must necessarily exhibit high association. METHODS: Radiographic and cosmetic indices of trunk and shoulder balance, along with posterior trunk symmetry index, were measured preoperatively and 3 months postoperatively in 33 Lenke 1C scoliosis patients. Pearson correlation analysis was performed. Paired t test was used to determine significant changes in radiographic and cosmetic indices after surgery. Independent-sample t test was used for all intergroup analyses in trunk shift and no-trunk-shift groups. RESULTS: Correlation coefficients between radiologic and cosmetic indices ranged between -0.63 and 0.70 with thoracic apical vertebra-central sacral vertical line (AV-CSVL) distance and first rib angle showing consistent correlations with cosmetic trunk and cosmetic shoulder balance indices. Trunk shift, a postoperative iatrogenic phenomenon, was seen in 19 (58%) patients. These patients had higher preoperative thoracic AV-CSVL translation, thoracic apical vertebra-first thoracic vertebra (AV-T1) translation, thoracic deformity correction rate, AV-T1 correction rates, and shorter fusions compared with the no-trunk-shift group. Posterior trunk symmetry index worsened in trunk shift group and improved significantly (-7.94 vs. 16.53) in no-trunk-shift group. Significant association (P=0.004) was seen between radiographic and cosmetic trunk shift. CONCLUSIONS: Radiographic indices can only minisculely (r≤0.7) reflect cosmetic deformity in Lenke 1C scoliosis, which emphasizes not only the vulnerability of overreliance on radiographic indices but also the vital importance of clinical cosmetic evaluations. In particular, cosmetic shoulder height and angle are not represented by radiographic indices. However, radiograph trunk shift was significantly associated with cosmetic trunk shift in cosmetic pictures.

Improved patient selection by stratified surgical intervention: Aarhus Spinal Metastases Algorithm.

BACKGROUND CONTEXT: Choosing the best surgical treatment for patients with spinal metastases remains a significant challenge for spine surgeons. There is currently no gold standard for surgical treatments. The Aarhus Spinal Metastases Algorithm (ASMA) was established to help surgeons choose the most appropriate surgical intervention for patients with spinal metastases. PURPOSE: The purpose of this study was to evaluate the clinical outcome of stratified surgical interventions based on the ASMA, which combines life expectancy and the anatomical classification of patients with spinal metastases to inform surgical decision making. STUDY DESIGN/SETTING: This is a retrospective study based on a prospective database. PATIENT SAMPLE: A consecutive series of 515 spinal metastatic patients who underwent surgically treatment from December 1992 to June 2012 in Aarhus University Hospital were included prospectively and analyzed in detail retrospectively. OUTCOME MEASURES: Survival time after surgery was determined for all patients. Neurological function was assessed using the Frankel score preoperatively and postoperatively (at the time of discharge). Complete outcome data were retrieved in 97.5% of this cohort. METHODS: Patients with spinal metastases were identified from an institutional database that prospectively collected data since 1992. Survival status data were obtained from a national registry. Neurological function was determined from the same institutional database or local Electronic Patient Journal system. Surgeons evaluated and classified patients into five surgical groups preoperatively by using the revised Tokuhashi score (TS) and the Tomita anatomical classification (TC). RESULTS: The overall median survival time of the cohort was 6.8 (95% confidence interval: 6.1-7.9) months. The median survival times in the five surgical groups determined by the ASMA were 2.1 (TS 0-4, TC 1-7), 5.1 (TS 5-8, TC 1-7), 12.1 (TS 9-11, TC 1-7 or TS 12-15, TC 7), 26.0 (TS 12-15, TC 4-6), and 36.0 (TS 12-15, TC 1-3) months. The 30-day mortality rate was 7.5%. Postoperative neurological function was maintained or improved in 469 patients (92.3%). Overall reoperation rate was 13.5%, commonly because of postoperative hematoma and new limb weakness. CONCLUSIONS: The ASMA recommends at least two surgical options for a particular patient by determining the preoperative life expectancy and anatomical classification of the spinal metastases. This algorithm could help spine surgeons to discriminate the risks of surgeries. The ASMA provides a tool to guild surgeons to evaluate the spinal metastases patients, select potential optimal surgery, and avoid life-threatening risks.

Postoperative spinal alignment remodeling in Lenke 1C scoliosis treated with selective thoracic fusion.

BACKGROUND CONTEXT: Selective thoracic fusion may cause spinal imbalance in certain patients; how the spinal alignment changes over time after surgery is highly correlated with the final spinal balance. PURPOSE: To investigate how spinal alignment changes over time after selective thoracic fusion and how spinal alignment remodeling affects spinal balance. METHODS: All adolescent idiopathic scoliosis (AIS) cases surgically treated in our institution between 2002 and 2008 were reviewed. Inclusion criteria were as follows: Lenke 1C scoliosis patients treated with posterior pedicle screw-only constructs; the lowest instrumented vertebra (LIV) ended at L1 level or above; and 2-year radiographic follow-up. Standing anteroposterior and lateral digital radiographs from four different time points (preoperatively, immediately, 3 months, and 2 years postoperatively) were reviewed. In each standing anteroposterior radiograph, the center sacral vertical line (CSVL, the vertical line that bisects the proximal sacrum) was first drawn, and the translation (deviation from the CSVL) of some key vertebrae was measured, such as the LIV, LIV+1 (the first vertebra below LIV), LIV+2 (the second vertebra below LIV), LIV+3 (the third vertebra below LIV), lumbar apical vertebra (AV), thoracic AV, and T1. Additionally, the Cobb angles of the major thoracic and lumbar curves were measured at different time points, and the correction rates were calculated. Furthermore, clinical photographs of the patients from the back were taken preoperatively and postoperatively. RESULTS: Of 278 AIS patients reviewed, 29 met the inclusion criteria. The continuous follow-up of our present study revealed an interesting phenomenon: postoperative spinal alignment remodeling. A hypothetical criterion was established to determine the onset of the phenomenon. By means of a series of analyses, the criterion was validated. The results of our present study showed that selective thoracic fusion tended to cause leftward spinal imbalance in these Lenke 1C AIS patients. Twenty of the 29 patients had leftward spinal imbalance immediately after surgery. Although some patients regained spinal balance through postoperative spinal alignment remodeling, 11 patients remained imbalanced at 2-year follow-up. CONCLUSIONS: Selective thoracic fusion is prone to cause leftward spinal imbalance in Lenke 1C scoliosis patients. Postoperative spinal alignment remodeling can facilitate recovery of spinal balance in some patients. Postoperative spinal imbalance in Lenke 1C scoliosis patients could be prevented by selecting stable vertebra or the vertebrae above as LIV, checking the balance condition during surgery, or considering ratio criteria when selecting candidates for selective thoracic fusion.

The predictive value of pain drawings in lumbar spinal fusion surgery.

BACKGROUND CONTEXT: Pain drawings have been used extensively in spine surgery. It has been associated with inferior outcome after disc and stenosis surgery. Results regarding the predictive value in fusion surgery have been conflicting. PURPOSE: To evaluate the predictive value of pain drawings in relation to outcome after lumbar spinal fusion. To investigate if there are differences between spondylolisthesis patients and patients with degenerative disease as well as between patients with or without radicular pain. STUDY DESIGN: Prospective clinical cohort with a minimum of 1-year follow-up. PATIENT SAMPLE: One hundred thirty-five patients undergoing lumbar spinal fusion. Fifty-seven men and 78 women, mean age 44 years (range 21-59 years). OUTCOME MEASURES: Dallas Pain Questionnaire (DPQ), Low Back Pain Rating Scale (LBPRS) pain index and patient satisfaction. Minimal clinical important difference was defined for the LBPRS score. METHODS: Pain drawings were classified, using the visual inspection method, as organic or nonorganic and correlated to outcomes. Multivariate adjustment for several possible confounding variables was done using logistic regression analysis. RESULTS: Thirty-three percent of the drawings were classified as nonorganic. Nonorganic drawings were associated with significantly higher DPQ and LBPRS scores preoperatively and at follow-up. Differences between organic and nonorganic drawings were larger in spondylolisthesis patients than in patients with degenerative disorders. Nonorganic pain drawings were associated with poorer outcome in patients with low back pain and radicular symptoms, however, not in patients without radicular symptoms. A nonorganic pain drawing predicted negative patient satisfaction with odds ratio (OR) 3.01 (95% confidence interval (CI): 1.14-8.55, p=.027) but had no significant predictive value with respect to improvement in the LBPRS pain index OR 1.92 (95% CI: 0.82-4.47, p=.132). CONCLUSIONS: A nonorganic pain drawing was a significant risk factor for inferior outcome after spinal fusion surgery. The predictive value did not allow for patient selection.

Femoral head histology subsequent to ischemia, reperfusion and steroid treatment.

An episode of ischemia followed by reperfusion of the femoral head (FH) is thought to be a common pathway in the pathogenesis of femoral head necrosis (FHN). Femoral head histology was investigated after short-term high-dose steroid treatment and femoral head ischemia and reperfusion in a large animal model. Twenty-two pigs were randomized to receive methylprednisolone 20mg/day/kg bodyweight intamuscularly for 3 days followed by methylprednisolone 10mg/day/kg bodyweight for 11 days (n=11), whereas the control group (n=11) received no treatment. After 6h of unilateral hip-joint pressure increase to 250mmHg, the pressure was discontinued and reperfusion was allowed for 4h. Undecalcified histology was performed for the femoral head subchondral region, the mid-region, and the region adjacent to the growth plate. Congestion phenomena were predominantly discerned in femoral head sections of the tamponaded hips. Histomorphometry revealed fat cell hyperthrophy and reduced hemopoetic marrow cells in the femoral heads of the steroid-treated group of animals. The number of blood vessels and bone trabeculae remained unchanged. These characteristics may correlate with early-stage femoral head necrosis.

Impact of instrumentation in lumbar spinal fusion in elderly patients: 71 patients followed for 2-7 years.

BACKGROUND AND PURPOSE: An increasing number of lumbar fusions are performed using allograft to avoid donor-site pain. In elderly patients, fusion potential is reduced and the patient may need supplementary stability to achieve a solid fusion if allograft is used. We investigated the effect of instrumentation in lumbar spinal fusion performed with fresh frozen allograft in elderly patients. METHODS: 94 patients, mean age 70 (60-88) years, who underwent posterolateral spinal fusion either non-instrumented (51 patients) or instrumented (43 patients) were followed for 2-7 years. Functional outcome was assessed with the Dallas pain questionnaire (DPQ), the low back pain rating scale pain index (LBPRS), and SF-36. Fusion was assessed using plain radiographs. RESULTS: Instrumented patients had statistically significantly better outcome scores in 6 of 7 parameters. Fusion rate was higher in the instrumented group (81% vs. 68%, p = 0.1). Solid fusion was associated with a better functional outcome at follow-up (significant in 2 of 7 parameters). 15 patients (6 in the non-instrumented group and 9 in the instrumented group) had repeated lumbar surgery after their initial fusion procedure. Functional outcome was poorer in the group with additional spine surgeries (significant in 4 of 7 parameters). INTERPRETATION: Superior outcomes after lumbar spinal fusion in elderly patients can be achieved by use of instrumentation in selected patients. Outcome was better in patients in which a solid fusion was obtained. Instrumentation was associated with a larger number of additional surgeries, which resulted in a lesser degree of improvement. Instrumentation should not be discarded just because of the age of the patient.

The positive effect of posterolateral lumbar spinal fusion is preserved at long-term follow-up: a RCT with 11-13 year follow-up.

INTRODUCTION: Few studies have investigated the long-term effect of posterolateral lumbar spinal fusion on functional outcome. AIM: To investigate the long-term result after posterolateral lumbar spinal fusion with and without pedicle screw instrumentation. METHODS: Questionnaire survey of 129 patients originally randomised to posterolateral lumbar spinal fusion with or without pedicle screw instrumentation. Follow-up included Dallas Pain Questionnaire (DPQ), Oswestry Disability Index (ODI), SF-36 and a question regarding willingness to undergo the procedure again knowing the result as global outcome parameter. RESULTS: Follow-up was 83% of the original study population (107 patients). Average follow-up time was 12 years (range 11-13 years). DPQ-scores were significantly lower than preoperatively in both groups (P < 0.005) and no drift towards the preoperative level was seen. No difference between the two groups were observed (instrumented vs. non-instrumented): DPQ Daily Activity mean 37.0 versus 32.0, ODI mean 33.4 versus 30.6, SF-36 PCS mean 38.8 versus 39.8, SF-36 MCS mean 49.0 versus 53.3. About 71% in both groups were answered positively to the global outcome question. Patients who had retired due to low back pain had poorer outcome than patients retired for other reasons, best outcome was seen in patients still at work (P = 0.01 or less in all questionnaires, except SF-36 MCS P = 0.08). DISCUSSION: Improvement in functional outcome is preserved for 10 or more years after posterolateral lumbar spinal fusion. No difference between instrumented fusion and non-instrumented fusion was observed. Patients who have to retired due to low back pain have the smallest improvement.

Circumferential fusion improves outcome in comparison with instrumented posterolateral fusion: long-term results of a randomized clinical trial.

STUDY DESIGN: Prospective randomized clinical study with a 5- to 9-year follow-up period. OBJECTIVE: The aim of the present study was to analyze the long-term outcome with respect to functional disability, pain, and general health of patients treated by means of circumferential lumbar fusion in comparison with those treated by means of instrumented posterolateral lumbar fusion. SUMMARY OF BACKGROUND DATA: Circumferential fusion has become a common procedure in lumbar spinal fusion both as a primary and salvage procedure. However, the claimed advantages of circumferential fusion over conventional posterolateral fusion lack scientific documentation. (The primary report with a 2-year follow-up has been published in Spine in 2002.) METHODS: From April 1996 to November 1999, a total of 148 patients (mean age, 45 years) with severe chronic low back pain were randomly selected for either posterolateral lumbar fusion (titanium Cotrel-Dubousset) or circumferential lumbar fusion (instrumented posterolateral fusion with anterior intervertebral support by a Brantigan cage). The primary outcome measure was the Dallas Pain Questionnaire (DPQ). The secondary outcome measures were the Oswestry Disability Index, the SF-36 instrument, and the Low Back Pain Rating Scale. All measures assessed the endpoint outcomes at 5 to 9 years after surgery. RESULTS: The available response rate was 93%. The circumferential group showed a significantly better improvement (P < 0.05) in comparison with the posterolateral group with respect to all four DPQ categories: daily activities, work/leisure, anxiety/depression, and social interest. The Oswestry Disability Index supported these results (P < 0.01). General health, as assessed by means of the SF-36, also showed significantly better physical health (P < 0.01) in the circumferential group, whereas no significant difference was found with respect to mental health compared with the posterolateral group. The circumferential group experienced significantly less back pain (P < 0.05) in comparison with the posterolateral group. In regard to leg pain, no significant difference was found. CONCLUSION: Circumferential lumbar fusion demands more extensive operative resources compared with posterolateral lumbar fusion. However, 5 to 9 years after surgery, the circumferentially fused patients had a significantly improved outcome compared with those treated by means of posterolateral fusion. These new results not only emphasize the superiority of circumferential fusion in the complex pathology of the lumbar spine but are also strongly supported in all of the validated questionnaires used in the study.

[Estimation of life expectancy for selecting surgical procedure and predicting prognosis of extradural spinal metastases].

BACKGROUND & OBJECTIVE: Clinically, whether and how to make a surgical interventional decision for the patients with spinal metastases is still controversial. Life expectancy is a significant determinant in the selection of surgical procedure for spinal metastases. This study was to evaluate Tomita and Tokuhashi scoring systems in selecting surgical procedure and predicting prognosis of extradural spinal metastases. METHODS: A total of 169 patients with spinal metastases, treated in the Spine Unit of Aarhus University Hospital, Denmark, from Jan. 2001 to Apr. 2004, were enrolled. The life expectancy was scored according to both Tomita system and Tokuhashi system before operation, the spinal metastases were classified according to Tomita system, and the patients underwent surgery accordingly. Follow-up was done 6, 12, and 24 months after operation. The precise of Tomita system and Tokuhashi system in estimating "death within 3 months", "death within 6 months", and "death within 12 months" was compared using Receiver Operating Characteristic curves (ROC curves). The mean survival time of the patients was calculated by Kaplan-Meier method. RESULTS: ROC curves of "death within 3 months", "death within 6 months", and "death within 12 months" showed no significant difference between Tomita score and Tokuhashi score in each group (P = 0.16, P = 0.47, and P = 0.38, respectively). Kaplan-Meier survival curves showed that Tomita system overestimated the prognosis in scores from 4 to 7, and Tokuhashi system underestimated the prognosis in scores from 0 to 8. CONCLUSIONS: Both Tomita and Tokuhashi scoring systems could be used to predict prognosis of spinal metastases after operation. Tokuhashi scoring system can predict early death more accurately, which can be used to avoid major operation for these patients.

Mid-tibial distraction osteogenesis redistributes bone blood flow: a microsphere study in rabbits.

BACKGROUND: Distraction osteogenesis can be used for the treatment of osteomyelitis and nonunion, conditions thought to benefit from increased blood flow in the bone tissue of the distracted limb. We have questioned whether such an increase occurs, and investigated the spatial distribution of bone blood flow after distraction osteogenesis. METHODS: The tibiae of 8 rabbits were lengthened 10 mm by a standard midtibial distraction osteogenesis procedure. 2 weeks into the consolidation phase, the bone and soft tissue blood flow of the distracted and the contralateral extremity were measured using radioactive microspheres. RESULTS: The absolute bone blood flow of the distracted tibia was 4% lower than that of the non-distracted side, representing a 41% decrease in the proximal metaphysis, a smaller decrease in the proximal epiphysis, distal metaphysis and distal epiphysis, and an increase in the diaphysis. INTERPRETATION: Mid-tibial distraction osteogenesis redistributed the bone blood flow of the distracted tibia, but absolute tibial blood flow did not increase. Our results do not confirm previous research in this field.

Recombinant human bone morphogenetic protein 2 enhances bone healing in an experimental model of fractures at risk of non-union.

INTRODUCTION: Identification of patients at risk of developing non-union and institution of procedures preventing non-union could be attractive in routine fracture management. We investigated whether recombinant human bone morphogenetic protein (rhBMP-2) delivered in a hyaluronic acid carrier could prevent non-union development in an experimental non-union model, which simulates the clinical situation of open mid-tibial fractures. METHODS: Sixteen rabbits underwent a standard non-union operation comprising mid-tibial osteotomy, excision of periosteum and endosteum, and plate fixation. Before closure of the wound eight rabbits received interfragmentary deposition of 200 microg rhBMP-2 delivered in a hyaluronan gel carrier, and eight rabbits received gel carrier alone. RESULTS: After 7 weeks, torsional failure moment of the osteotomy and energy absorbed at failure, macroscopic and radiographic appearance, callus area, and interfragmentary bone volume fraction confirmed that rhBMP-2 delivery significantly improved bone healing. Blood flow at the osteotomy site, measured using radiolabelled microspheres, was not higher in the united osteotomies than in non-united osteotomies. DISCUSSION: rhBMP-2 delivered in a hyaluronic acid carrier-induced formation of competent bone in an experimental model of compromised healing. We, therefore, propose interfragmentary deposition of rhBMP-2 delivered in a hyaluronic acid carrier to patients encountering fractures at risk of non-union or delayed union.

Methylprednisolone enhances contraction of porcine femoral head epiphyseal arteries.

The pathomechanism of steroid-induced femoral head necrosis is thought to be disturbed femoral head blood flow. We hypothesize that methylprednisolone increases vasocontraction of femoral head epiphyseal arteries, thereby reducing femoral head blood flow. Nine immature female domestic pigs were randomly selected from a group of 18 to receive 24-hour methylprednisolone treatment, whereas the nine remaining pigs received the placebo control in a blinded fashion. After sacrifice, lateral epiphyseal artery segments from the femoral heads were mounted as ring preparations on a small vessel myograph. Isometric active tension was measured in relation to cumulating doses of the vasoconstrictors noradrenaline and endothelin-1, and the vasodilator bradykinin. Vasocontraction to noradrenaline was not altered by methylprednisolone. Bradykinin elicited a concentration-dependent vasodilation which was lower in the corticosteroid-treated vessels. Vasoconstriction to endothelin-1 was stronger in the corticosteroid-treated vessels. Our data indicate that methylprednisolone enhances contraction of femoral head lateral epiphyseal arteries and may decrease femoral head blood flow. To our knowledge, this pathomechanic factor in femoral head necrosis has not been described before.

Femoral head blood flow reduction and hypercoagulability under 24 h megadose steroid treatment in pigs.

The pathogenesis of corticosteroid-induced femoral head necrosis is assumed to be ischemia. The purpose of this study was to investigate the perfusion pattern of the femoral head and plasma coagulability during 24 h corticosteroid megadose treatment, as recommended by the National Acute Spinal Cord Injury Studies (NASCIS), in the awake big animal model. Blindedly, 9 animals underwent megadose methylprednisolone infusion (30 mg/kg intravenously as an initial bolus, followed by 5.4 mg/kg/h for further 23 h) while 9 animals served as placebo treated controls. Regional blood flow of the systematically subdivided femoral head, proximal femur, acetabulum, and soft tissue hip regions was investigated by the microsphere technique at steady state (phase 1), after the initial bolus infusion (phase 2), and after the completed treatment (phase 3). Plasma coagulability was examined in phases 1 and 3. Blood flow of the femoral head epiphysis and metaphyseal cancellous bone was unchanged after one hour of steroid infusion, but decreased after the completed treatment at 24 h in the experimental group. Femoral head blood flow reduction was global without a tendency to more pronounced blood flow decrease in any subregion. Plasma fibrinogen was significantly higher after 24 h of steroid infusion than in the placebo control group. 24 h high dose methylprednisolone treatment causes femoral head blood flow reduction and hypercoagulability of plasma in the normal awake immature pig. These findings may be pathogenetic factors in the early stage of steroid-induced osteonecrosis.

Spinal blood flow in 24-hour megadose glucocorticoid treatment in awake pigs.

OBJECT: Because of the controversy regarding the benefits of 24-hour administration of methylprednisolone in patients with spinal cord injury (SCI), it is important to investigate its mechanism of action and side effects. This study was conducted to determine if high-dose methylprednisolone modulates neural and vertebral blood flow in an awake large-sized animal model without SCI. METHODS: From a group of 18 immature female domestic pigs born to nine different litters, nine animals were randomly allocated to receive methylprednisolone treatment, whereas their nine female siblings served as controls. Drug or placebo was applied in a blinded fashion by a third person not involved in the study. The following treatment for SCI, as suggested by the North American Spinal Cord Injury Study, was administered to the awake pig: methylprednisolone (30 mg/kg of body weight) was infused into the jugular vein during a 15-minute period, followed by a 45-minute pause, and the infusion was maintained over a 23-hour period at a dose of 5.4 mg/kg body weight/hour. By means of the radioactive tracer microsphere technique, spinal cord blood flow (SCBF) was measured in the awake standing pig in the cerebrum, and in spinal gray and white matter, nerve roots, endplates, cancellous bone, cortical shell, and T12-L2 discs. Blood flow was measured before, 1 hour after initiation of infusion, and 24 hours postinfusion. Examination of blood flow in the neural and vertebral tissue samples, as well as of central hemodynamics, revealed no significant difference between the experimental and control groups, and this parity was maintained throughout the experimental phases. CONCLUSIONS: In the awake pig model, 24-hour methylprednisolone treatment does not modulate cerebral or SCBF, nor does it increase the risk for vertebral osteonecrosis by producing vertebral ischemia.

Pain 5 years after instrumented and non-instrumented posterolateral lumbar spinal fusion.

Pain drawings have been used in spine surgery for diagnostic use and psychological evaluation of fusion candidates; they have rarely been used to evaluate pain status after spinal fusion. This study is a 5-year follow-up on a randomised clinical trial assigning patients to posterolateral spinal fusion with or without pedicle screw instrumentation. Patients were mailed a pain drawing and questionnaires including questions regarding work, social status, smoking status, the Dallas Pain Questionnaire (DPQ), and the Low Back Pain Rating Scale (LBPRS). Pain drawings were scored using a visual inspection method and a surface-based point scoring and evaluated for the presence of donor site pain. Pain drawings from 109 patients (87% of the initially included patients), 56 men and 53 women, mean age at follow-up 51 years, were analysed. Fifty-three patients had undergone an instrumented fusion and 56 a non-instrumented fusion. Some presence of low back pain was marked by 79% and leg pain by 69%. Sixty-two percent of the pain drawings were classified as "organic" and 38% as "non-organic". There was no difference between the instrumented and the uninstrumented group. DPQ and LBPRS scores were higher in the non-organic group ( P=0.007). Using the point scoring, no difference between the instrumented and the uninstrumented group was seen. The results of the point scoring were found to correlate with the DPQ and LBPRS scores ( P=0.001). Working patients (39%) had significantly better scores than the rest. Ten percent of the patients had donor site pain. Twenty percent of spinal fusion patients are totally pain free at 5-year follow-up. Ten percent still experience donor site pain. In general, instrumentation does not affect the amount and localisation of pain 5 years after lumbar spinal fusion surgery. The pain drawing seems to be a valuable tool when following spinal fusion patients, but its use as prognostic marker in connection with fusion surgery needs further investigation.

Effects of locally applied vascular endothelial growth factor (VEGF) and VEGF-inhibitor to the rabbit tibia during distraction osteogenesis.

INTRODUCTION: Therapeutic angiogenesis, a novel concept in tissue engineering, is neo-formation of blood vessels in a tissue upon delivery of an angiogenic growth factor to the tissue. We hypothesised that therapeutic angiogenesis could enhance bone formation and challenged the hypothesis in an experimental model of distraction osteogenesis. METHODS: Rabbits, divided into three equal groups of 12, had their right tibia lengthened by distraction osteogenesis. A mini-osmotic pump delivered to the osteotomy gap either recombinant human vascular endothelial growth factor (VEGF), VEGF-inhibitor, or vehicle alone during the latency and distraction phase. After consolidation, we assessed bone blood flow by radioactive microsphere entrapment, measured torsional stiffness and bone mineral content, and did histomorphometry. RESULTS: VEGF and VEGF-inhibitor treatment failed to influence bone blood flow, torsional stiffness, bone mineral content and histomorphometric indices of the bone regenerate. However, VEGF treatment increased the blood flow in bone of the distracted limb and VEGF-inhibitor treatment decreased bone blood flow. CONCLUSION: The regenerate was unresponsive to VEGF and VEGF-inhibitor treatment in contrast to the neighbouring bone, which implies different biological properties of the vasculature in native and regenerating bone. VEGF is not recommended for enhancement of bone formation in this setting.

In vitro osteoblast-like cell metabolism in spondylodesis--a tool that may predict fusion capacity: a prospective study in 50 patients with a 1-year follow-up.

In vitro cultures of human primary osteoblast-like cells provide a model for studying cellular mechanisms associated with human bone biology. We investigated in vitro osteoblast-like cell metabolism as a method for predicting the occurrence of spinal fusion in the individual patient. A bone biopsy was taken from the iliac crest of 50 patients, median age 49 (23-77) years, who were undergoing lumbar spine fusion. First-passage osteoblast-like cells were established by the bone-tissue-explant method. We then estimated 3H-thymidine incorporation, alkaline phosphatase activity and procollagen I production. Fusion rates were evaluated at the 1-year follow-up. Primary human osteoblast-like cell cultures showed an age-dependent decline in their capacity for cellular outgrowth and expression of alkaline phosphatase, which suggested a useful biological response pattern of the osteoblast culture. However, such cultures were unsatisfactory as an in vitro tool for predicting fusion capacity.

Circumferential lumbar spinal fusion with Brantigan cage versus posterolateral fusion with titanium Cotrel-Dubousset instrumentation: a prospective, randomized clinical study of 146 patients.

STUDY DESIGN: A prospective randomized clinical study with a 2-year follow-up period was conducted. OBJECTIVE: To analyze the effects of circumferential fusion using ALIF radiolucent carbon fiber cages and titanium posterior instrumentation on functional outcome, fusion rate, complications, and lumbar lordosis. SUMMARY OF BACKGROUND DATA: Circumferential fusion has become a common procedure in lumbar spine fusion, both as a primary and salvage procedure. However, the claimed advantages of ALIF plus PLF over conventional PLF lack scientific documentation. METHODS: From April 1996 through November 1999, a total of 148 patients with severe chronic low back pain were randomly selected for either posterolateral lumbar fusion with titanium CD-Horizon (posterolateral group) or circumferential fusion with a ALIF Brantigan cage plus posterior instrumentation. The Dallas Pain Questionnaire (DPQ), the Low Back Pain Rating Scale (LBPR), and a questionnaire concerning work status assessed their outcomes. RESULTS: Both groups showed highly significant improvement in all four categories of life quality (DPQ) as well as in the back pain and leg pain index (LBPR), as compared with preoperative status. There was a clear tendency toward better overall functional outcome for patients with the circumferential procedure ( < 0.08), and this patient group also showed significantly less leg pain at the 1-year follow-up evaluation ( < 0.03) and less peak back pain at 2 years ( < 0.04). Sagittal lordosis was restored and maintained in the circumferential group ( < 0.01). The circumferential fusion patients showed a higher posterolateral fusion rate (92%) than the posterolateral group (80%)( < 0.04). The repeat operation rate including implant removal was significantly lower in the circumferential group (7%) ( < 0.009) than in the posterolateral group (22%). CONCLUSIONS: Circumferential lumbar fusion restored lordosis, provided a higher union rate with significantly fewer repeat operations, showed a tendency toward better functional outcome, and resulted in less peak back pain and leg pain than instrumented posterolateral fusion. The clinical perspective of the current study implies a recommendation to favor circumferential fusion as a definitive surgical procedure in complex lumbar pathology involving major instability, flatback, and previous disc surgery in younger patients, as compared with posterolateral fusion with pedicle screws alone.

Effect of methylprednisolone on reperfusion after femoral head ischemia.

An episode of ischemia and reperfusion of the femoral head is thought to be the common pathway in the pathogenesis of femoral head necrosis. The influence of short-term high-dose steroid treatment on femoral head reperfusion after ischemia was investigated in a porcine model. Twenty-two pigs were randomized to receive methylprednisolone 20 mg/day/kg bodyweight intramuscularly for 3 days followed by methylprednisolone 10 mg/day/kg bodyweight for 11 days (n = 11), whereas the control group (n = 11) received no treatment. Femoral head ischemia was achieved by 6 hours of unilateral intraarticular hip pressure increase to 250 mm Hg. Femoral head blood flow was estimated using radiolabeled microspheres (15 microm in diameter) before ischemia, during hip tamponade, and 4 hours after tamponade release. Femoral head blood flow was lower in the corticosteroid treated pigs. Subtotal femoral head ischemia was documented in both groups during joint tamponade. Apart from two femoral head epiphyses in either group, reperfusion after tamponade release on the average occurred to a blood flow level similar to that before ischemia. Short-term high-dose methylprednisolone treatment depressed bone perfusion in general, but had no effect on reperfusion after femoral head ischemia in the porcine model.

The effect of long-term methylprednisolone treatment on the femoral head in growing pigs.

The effect of long term steroid treatment on coagulation, intraosseous pressure (IOP), femoral head (FH) blood flow, and histology in the normal organism was investigated in this study in growing pigs. From 24 growing female Danish Landrace pigs from 12 litters, 12 animals daily received 100 mg methylprednisolone orally for three months. Their 12 sister pigs served as controls without steroid treatment. Prothrombin time, activated partial thromboplastin time (aPTT), fibrinogen, and antithrombin III levels were recorded in jugular venous blood. Blood flow of the hip regions was measured by means of the radioactive microsphere technique. Metaphyseal and epiphyseal IOP of the left or right proximal femur were measured. Histomorphometry of the left or right FH epiphysis was performed. Major growth inhibition was found in the corticosteroid (CS) treated group. In CS pigs, aPTT was shortened to 50% compared to control pigs. Plasma fibrinogen was higher in the CS animals. Total FH blood flow was not different while regional blood flow in the cranial subregion of the FH epiphysis was higher in the CS group. Metaphyseal and epiphyseal IOP of the proximal femur were not different in the CS animals. Histomorphometrically, cancellous bone volume (23 +/- 1% vs. 34 +/- 2%; p < 0.001) and bone turnover (10 +/- 2% vs. 55 +/- 8%; p < 0.001) of the FH epiphysis was lowerin the CS than in the control group. The FH epiphysis of the CS animals invariably showed an irregular cartilage-bone interface with cartilaginous projections into the subchondral bone mainly in its cranial part. In normal growing pigs, long term high dose CS treatment has induced a hypercoagulable state of plasma via the intrinsic pathway of coagulation, cartilaginous projections into FH subchondral bone, FH osteopenia, and reduced bone turnover. Long-term steroid treatment did not produce FH necrosis or FH IOP alterations in the immature pig model.