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Introduction: This study aims to describe a novel minimal invasive early-onset scoliosis (EOS) growth rod concept, the Cody Bünger (CB) Concept, which combines concave interval distraction and contralateral-guided growth with apical control and to investigate the 3D deformity correction, the spinal growth, and the pulmonary development. Method: A series of 38 children with progressive EOS and growth potential, receiving a highly specialized surgical treatment, including primary and conversion cases. Mean age was 10.2 years (4.4–15.8) with a mean follow-up of 5.6 years, and they underwent 168/184 open/magnetic lengthening procedures. Outcomes were as follows: scoliosis, kyphosis, and lordosis angles; apical rotation; spinal length; apical translation; coronal and sagittal vertical alignment; complications; and pulmonary function in a subgroup. Results: Scoliosis improved from mean 76° (46–129) to 35° (8–74) post-op and was 42° (13–83) at end of treatment. Apical rotation was reduced by 30% but was partially lost during treatment. Thoracic kyphosis initially decreased by mean 15° and was partially lost during treatment. Lordosis was largely unaltered during treatment. Mean T1-S1 height increased from 30.7 cm (22.7–39.2) to 34.6 cm (27.8–45.1) postop and further increased to 38.5 cm (30.1–48.1) during treatment. This corresponded to a T1-S1 growth rate of 12 mm/year, and positive growth rates were found in all height parameters evaluated. Frontal balance and apical translation improved, whereas sagittal balance was unaltered. Complications occurred in 22/38 patients, and 11/38 had an unintended reoperation. Pulmonary function (FVC and FEV) increased but the relative lung function was unchanged. Conclusion: The new growth rod concept provided 3D correction and spinal growth at complication rates comparable with other growth-friendly techniques for EOS, while pulmonary function was preserved. Single magnetic rod distraction was incorporated successfully, replacing surgical elongations.

Early-Onset Scoliosis (EOS) treatment aim to improve natural history and the child’s quality of life. Magnetically Controlled Growing-Rods (MCGRs) represented a major evolution in distraction-based management of EOS by eliminating the surgical elongations.

Charcot's spine is a long-term complication of spinal cord injury. The lesion is often localized at the caudal end of long fusion constructs and distal to the level of paraplegia. However, cases are rare and the literature relevant to the management of Charcot's arthropathy is limited. This paper reviews the clinical features, diagnosis, and surgical management of post-traumatic spinal neuroarthropathy in the current literature. We present a rare case of adjacent level Charcot's lesion of the lumbar spine in a paraplegic patient, primarily treated for traumatic spinal cord lesion 39 years before current surgery. We have performed end-to-end apposition of bone after 3 column resection of the lesion, 3D correction of the deformity, and posterior instrumentation using a four-rod construct. Although the natural course of the disease remains unclear, surgery is always favorable and remains the primary treatment modality. Posterior long-segment spinal fusion with a four-rod construct is the mainstay of treatment to prevent further morbidity. Our technique eliminated the need for more extensive anterior surgery while preserving distal motion.

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.

Objective: Bioabsorbable barrier membranes placed over alveolar ridge bone defects are routinely used in dental surgery to promote bone formation. Combining these osteoconductive membranes with osteoinductive Bone Morphogenetic Proteins could prove useful in long bone fracture treatment. The hypothesis was tested in a clinically relevant model of compromised healing. Methods: Four groups of 8 rabbits underwent unilateral mid-tibial osteotomy, excision of periosteum and endosteum, and plate fixation. One group had rhBMP-2 deposited between the bone ends and Membrane wrapped around the osteotomy, the second group had Membrane wrapped around the osteotomy, the third group had rhBMP-2 placed between the bone ends, and the fourth group received no additional treatment. Results: After 7 weeks, callus size and blood flow were significantly higher in the Membrane+rhBMP-2 group than in the rhBMP-2 treated group, but torsion to failure test showed no significant difference. Membrane treatment and no treatment led to non-union. Conclusion: Absorbable barrier membrane combined with rhBMP-2 enhances bone formation, but has no advantage to rhBMP-2 alone. Membrane alone wrapped around the osteotomy was unable to prevent non-union formation.

STUDY DESIGN: Historical, register-based cohort study following 85 patients in the course of a time frame extending from two years before to two years after trauma occurrence.OBJECTIVE: To investigate the cost-effectiveness of surgery versus conservative management for thoracolumbar burst fractures.SUMMARY OF BACKGROUND DATA: Despite the prevalence of thoracolumbar burst fractures, consensus has as yet not been reached in terms of their clinical management and while from a health policy point of view, efficient use of resources is equally important, literature pertaining to this aspect is limited.METHODS: Consecutive patients who were admitted to a university clinic between 2004 and 2008 due to CT-verified AO type A3 fractures (T11-L2), age 18-65 years Patients with neurological compromise, osteoporosis, or malignancy were not included. The cost parameter defined primary- and secondary health- care use (2010-&OV0556;) and the effect parameter was based on three alternative measures of pain medication: (morphine milligram and defined daily doses (DDD) of narcotic and non-narcotic analgesics). For cost-effectiveness analysis, we employed a difference-in-difference approach, including control for treatment selection (age, gender and fracture type). Non-parametric bootstrapping was used to estimate conventional 95% confidence intervals of mean estimates.RESULTS: When taking into consideration all health care consumption, surgical management was observed to cost an additional &OV0556;10,734(4,215;15,144) as compared with conservative management. The differences on morphine at 527(-3,031;6,016) milligram, narcotic analgesics at -8(-176;127) DDD and non-narcotic analgesics at -3(-72;58) DDD were all insignificant The probability for surgery being cost-effective did not exceed 50% for any value of willingness to pay for effect.CONCLUSION: Surgical management does not seem to be a cost-effective strategy as compared with conservative management for traumatic thoracolumbar burst fractures without neurological deficits. Additional, higher-volume studies examining the clinical effect of alternative management strategies would be valuable.LEVEL OF EVIDENCE: 3.

STUDY DESIGN.: A risk factor analysis study. OBJECTIVE.: To identify the causative factors for postoperative trunk shift in Lenke 1C scoliosis and investigate how to prevent it. SUMMARY OF BACKGROUND DATA.: When selective thoracic fusion is performed, postoperative trunk shift is a significant problem in the management of Lenke 1C scoliosis. It is often accompanied by unsatisfactory clinical outcomes and a risk of reoperation. METHODS.: We reviewed all the patients with adolescent idiopathic scoliosis (AIS) surgically treated in our institution from 2002 through 2008. Inclusion criteria were as follows: (1) patients with Lenke 1C curves who were treated with selective thoracic fusion using posterior pedicle screw-only constructs; (2) the lowest instrumented vertebra (LIV) ending at L1 level or above; and (3) 2-year radiographical follow-up. Eighteen radiographical parameters were chosen as potential risk factors. The 18 parameters measured (1) amount of correction obtained by surgery; (2) preoperative position of LIV; (3) magnitude of major thoracic and thoracolumbar/lumbar (MT and TL/L) curves and ratio of MT: TL/L curve; and (4) curve flexibility. Both comparative and correlation analyses were performed. Those parameters that had shown highest correlation with the 2-year thoracic apical vertebra-center sacral vertical line (AV-CSVL) distance were selected to form a linear regression model, by which the correlations were quantified. RESULTS.: Of the 278 patients reviewed, 44 met the inclusion criteria. The parameters that measured the preoperative position of LIV and ratio of MT: TL/L curve showed high correlation with the 2-year thoracic AV-CSVL distance. With regard to the parameters that measured the amount of correction obtained by surgery, only the correction of the thoracic AV-T1 distance showed low correlation. Among the 18 parameters, preoperative lowest instrumented vertebra-lower end vertebra (LIV-LEV) difference and ratio of MT: TL/L Cobb angle were selected to form a formula to help predict postoperative trunk shift. The formula was as follows: 2-year thoracic AV-CSVL distance = -26.6 + 22.7 (ratio of MT: TL/L Cobb angle) - 3.9 (preoperative LIV-LEV difference). The model R = 0.55. CONCLUSION.: Both LIV selection and ratio of MT: TL/L curve were found to be highly correlated with the onset of postoperative trunk shift in Lenke 1C scoliosis. Amount of correction obtained by surgery, however, did not seem to be an independent causative factor. Postoperative trunk shift is less likely to occur when selecting LEV as LIV and the ratio of MT: TL/L Cobb angle of 1.2° or more.

BACKGROUND AND PURPOSE: There is a lack of evidence on the broad health-care costs of treating spine trauma patients without neurological deficits conservatively. The aim of the present study was to estimate the primary and secondary health-care sector costs associated with conservative treatment of spine fractures as well as their determinants.METHODS: Patients were identified between 1999 and 2008 in the hospital's administrative system based on relevant diagnostic codes. Inclusion criteria were: (1) spine fractures (C1-L5); (2) age >18; and (3) conservative treatment. Exclusion criteria were: (1) neurological involvement and (2) fractures secondary to osteoporosis/malignancy. Health-care utilization and costs were retrieved from national administrative databases covering the entire health-care sector.RESULTS: 201 cervical, 150 thoracic, and 140 lumbar fracture patients were included in the study. The total health cost was estimated at €18,919 (16,199; 21,756), €8571 (6062; 11,733), €5526 (3473; 7465) for cervical, thoracic, and lumbar regions, respectively. Hospital admissions accounted for the vast majority of costs while primary health care accounted for less than 3 % and prescription medication for less than 2 %. The determinants of costs included fracture site (p < 0.001) and concomitant lower limb injuries (p = 0.009).CONCLUSIONS: Spinal fractures, even mild ones, appear to incur substantial health-care utilization and costs. Health-care costs in conjunction with cervical fractures are more than two-fold of those affiliated with thoracic and lumbar fractures. Among the concomitant injuries, lower limb injuries exert a substantial influence over health-care costs.

PURPOSE:The aim of this study was to investigate whether or not post-op curve behaviour differs due to different choices of lowest instrumented vertebra (LIV) with reference to lumbar apical vertebra (LAV) in Lenke 3C and 6C scoliosis.METHODS:We reviewed all the AIS cases surgically treated in our institution from 2002 through 2008. Inclusion criteria were as follows: (1) patients with Lenke 3C or 6C scoliosis who were treated with posterior pedicle screw-only constructs; (2) 2-year radiographic follow-up. All the included patients were categorized into three groups based on the relative position of LIV and LAV: Group A-the LIV was above the LAV; Group B-the LIV was at the LAV; Group C-the LIV was below the LAV. All the radiographic parameters were then compared among the groups. All image data were available in our picture archiving and communication systems. Standing anteroposterior (AP) and lateral digital radiographs were reviewed at four times (pre-op, post-op, 3-month and 2-year). In each standing AP radiograph, centre sacral vertical line (CSVL, the vertical line that bisects the proximal sacrum) was first drawn, followed by measuring T1-CSVL, LIV-CSVL, (LIV + 1)-CSVL, LAV-CSVL and thoracic AV-CSVL distance. In addition, the Cobb angles of major thoracic and lumbar curves were measured at the four times and the correction rates were then calculated.RESULTS:Of the 278 patients reviewed, 40 met the inclusion criteria; 11 of these were included in Group A (LIV above LAV), another 11 in Group B (LIV at LAV) and the remaining 18 in Group C (LIV below LAV). At 2-year follow-up, the lumbar vertebrae such as LIV, LIV + 1 and LAV were all more deviated than before surgery in Group A (LIV above LAV), whereas in Group B and C (LIV at and below LAV) they were all less deviated than before surgery. No significant differences were found in thoracic or lumbar correction rate, global coronal balance and incidence rate of trunk shift among the three groups.CONCLUSION:In conclusion, in Lenke 3C and 6C scoliosis, post-op lumbar curve behaviour differs due to different choices of LIV with reference to LAV, that is, the deviation of lumbar curve improves when the LIV is either at or below the LAV but deteriorates when the LIV is above the LAV. Although the greatest correction occurs when the LIV is below the LAV, choosing LAV as LIV can still be the optimal option in certain cases, since it can yield similar correction while preserving more lumbar mobility and growth potential.

PURPOSE: To investigate the correction effectiveness, incidence rate of distal adding on, and post-operative spinal balance in Lenke 3C and 6C AIS treated with extensive fusion using posterior pedicle screw-only constructs. METHODS: We reviewed all AIS cases surgically treated in our institution between 2002 and 2008. The inclusion criteria were as follows: (1) Lenke 3C or 6C scoliosis patients who were treated with extensive fusion using posterior pedicle screw-only constructs; (2) minimum two year radiographic follow-up; (3) the lowest instrumented vertebra (LIV) ended at L2, L3 or L4 level. All image data were available in our picture archiving and communication systems (PACSs) , and all radiographic measurements were performed. Standing anteroposterior (AP) and lateral digital radiographs were reviewed at four different time points (pre-op, post-op, three months, and two years). In each standing AP radiograph, CSVL (center sacral vertical line, the vertical line bisecting the proximal sacrum) was first drawn, followed by measurement of the translation (deviation from the CSVL) of some key vertebrae, such as the lowest instrumented vertebra (LIV), LIV + 1 (the first vertebra below LIV), lumbar apical vertebra, thoracic apical vertebra and T1, enabling depiction of how translation of different parts of the spine changes over time. Additionally, the Cobb angles of major thoracic and lumbar curves were measured at the different time points and the correction rate was calculated. RESULTS: Of the 278 patients reviewed, 25 met the inclusion criteria. Immediately after surgery, satisfactory corrections were achieved from the perspective of not only Cobb angle but also vertebral translation. And the corrections were well retained in the following two years. The incidence rate of distal adding-on was low in this group of patients. In the course of two years following surgery, only six patients had an increase of greater than 5 mm in LIV + 1 translation, and among which only two patients had greater than 10 mm. Regarding global balance, overall, it neither improved nor deteriorated after extensive fusion. Furthermore, trunk shift was found in only three patients at two year follow-up. CONCLUSIONS: In Lenke 3C and 6C scoliosis, extensive fusion can produce satisfactory corrections from the perspectives of both Cobb angle and vertebral translation and rarely causes significant distal adding-on, global imbalance or trunk shift.

Udgivelsesdato: 2009-Oct-1 STUDY DESIGN: Randomized, controlled, multi-center trial. OBJECTIVE: To investigate the effect of direct current (DC) electrical stimulation on functional and clinical outcome after lumbar spinal fusion in patients older than 60 years. SUMMARY OF BACKGROUND DATA: Older patients have increased complication rates after spinal fusion surgery. Treatments which have the possibility of enhancing functional outcome and fusion rates without lengthening the procedure could prove beneficial. DC-stimulation of spinal fusion has proven effective in increasing fusion rates in younger and "high risk" patients, but functional outcome measures have not been reported. METHODS: A randomized, clinical trial comprising 5 orthopedic centers. The study included a total of 107 patients randomized to uninstrumented posterolateral lumbar spinal fusion with or without DC-stimulation. Functional outcome was assessed using Dallas Pain Questionnaire, SF-36, Low Back Pain Rating Scale pain index, and walking distance. RESULTS: Follow-up after 1 year was 95/107 (89%). DC-stimulated patients had significant better outcome in 3 of 4 categories in the Dallas Pain Questionnaire, better SF-36 scores (not significantly), but no difference in pain scores were observed. Median walking distance at latest follow-up was better in the stimulated group (not significant). Walking distance was significantly associated with functional outcome. There was no difference in any of the functional outcome scores between patients who experienced a perioperative complication and those without complications. CONCLUSION: The achievement of a good functional outcome was heavily dependent on the obtained walking distance. DC-stimulated patients tended to have better functional outcome as compared to controls. No negative effects of perioperative complications could be observed on the short-term functional outcome.

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.

Udgivelsesdato: 2009-Nov 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.

PURPOSE OF THE STUDY The aim of this study was to evaluate bone blood flow of the proximal femur during experimentally induced ischemia and to document the ability of epiphyseal and metaphyseal reperfusion. METHODS 11 pigs (danish landrace) were used to investigate the effect of tamponade by increased joint pressure (Dextran 70) on the perfusion of the femoral head. Additional 8 pigs were used as control. The blood flow in the hip joint was studied by means of the microsphere technique. The flow was determined before, during and after intraarticular pressure increase. With the "radioactive tracer microsphere"-method the blood flow of the epiphysis, metaphysis and proximal femoral corticalis could be measured. RESULTS In the epiphyseal femoral head the initial blood flow rate, 11.7 ml/min/100 g, was not significant different from that of the control side (11.1 ml/min/100 g). The blood flow decreased in the ischemic phase to 1.8 ml/min/100 g followed by reperfusion to 13.5 ml/min/100 g (p < 0.01). The bone blood flow of reperfusion was not significant different from that of the initial blood flow rate but in 2 cases a "blow out" of the epiphyseal bone blood flow was seen. The proximal femoral metaphysis showed the highest of the measured intraosseous flow rates (17.9 resp. 23.3 ml/min/100 g). During ischemia and reperfusion of the epiphysis bone blood flow of the metaphysis remained the same. The proximal femoral corticalis showed the lowest of the measured intraosseous flow rates. The operated (10.1 ml/min/100 g) and contralateral hip side (11.7 ml/min/100 g) showed no significant differences in the initial blood flow rate. During ischemia and reperfusion the blood flow of the proximal corticalis showed no significant difference to the initial blood flow corresponding to the metaphysis. CONCLUSIONS Our study demonstrates disturbances of the circulation of different regions of the femoral head during intraarticular pressure increase and following pressure decrease of the growing pig. 2 "blow outs" document a vulnerable proximal epiphysis already after a 6-hour ischemia. Additional minor "bone quality" in cases of certain diseases (kidney transplantation, leukemia) and special administration of drugs (corticosteroids) seem to create an additional vulnerability of the proximal femoral head. The experiment proves to be a reliable model for decreasing the blood flow of the growing epiphysis temporarily and to document the beginning of normal reperfusion. With this model it is possible to examine the vulnerability of the epiphyseal perfusion after different diseases and under the influence of different medication.

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 (AIS) 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 AIS 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 (POTSI), were measured preoperatively and three months postoperatively in 33 Lenke 1C scoliosis patients. Pearson's 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 inter-group analyses in trunk shift and no-trunk-shift groups.RESULTS:: Correlation coefficients between radiologic and cosmetic indices ranged between -0.63-0.70 with thoracic apical vertebra-central sacral vertical line (AV-CSVL) distance and first rib angle (FRA) 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 apical vertebra-central sacral vertical line (AV-CSVL) translation, thoracic apical vertebra-first thoracic vertebra (AV-T1) translation, thoracic deformity correction rate, AV-T1 correction rates and shorter fusions compared to the no-trunk-shift group. POTSI 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.CONCLUSION:: Radiographic indices can only minisculely (r≤0.7) reflect cosmetic deformity in Lenke 1C scoliosis, which emphasizes not only the vulnerability of over-reliance 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.

A retrospectively designed long-term follow-up study of adolescent idiopathic scoliosis (AIS) patients who had completed treatment, of at least 2 years, by means of brace, surgery, or both brace and surgery. This study is to assess the outcome after treatment for AIS by means of the Scoliosis Research Society Outcome Instrument 24 (SRS 24). One hundred and eighteen AIS patients (99 females and 19 males), treated at the Aarhus University Hospital from January 1, 1987 to December 31, 1997, were investigated with at least 2 years follow-up at the time of receiving a posted self-administered questionnaire. Forty-four patients were treated with Boston brace (B) only, 41 patients had surgery (S), and 33 patients were treated both with brace and surgery (BS). The Cobb angles of the three treatment groups did not differ significantly after completed treatment. The outcome in terms of the total SRS 24 score was not significantly different among the three groups. B patients had a significantly better general (not treatment related) self-image and higher general activity level than the total group of surgically treated patients, while surgically treated patients scored significantly better in post-treatment self-image and satisfaction. Comparing B with BS we found a significantly higher general activity level in B patients, while the BS group had significantly higher satisfaction. There were no significant differences between BS and S patients in any of the domain scores. All treatment groups scored “fair or better” in all domain scores of the SRS 24 questionnaire, except in post-treatment function, where all groups scored worse than “fair”. Improvement of appearance by means of surgical correction increases mean scores for post-treatment self-image and post-treatment satisfaction. Double-treatment by brace and surgery does not appear to jeopardize a good final outcome.

The re-establishment of vascularity is an early event in fracture healing; upregulation of angiogenesis may therefore promote the formation of bone. We have investigated the capacity of vascular endothelial growth factor (VEGF) to stimulate the formation of bone in an experimental atrophic nonunion model. Three groups of eight rabbits underwent a standard nonunion operation. This was followed by interfragmentary deposition of 100 μg VEGF, carrier alone or autograft. After seven weeks, torsional failure tests and callus size confirmed that VEGF-treated osteotomies had united whereas the carrier-treated osteotomies failed to unite. The biomechanical properties of the groups treated with VEGF and autograft were identical. There was no difference in bone blood flow. We considered that VEGF stimulated the formation of competent bone in an environment deprived of its normal vascularisation and osteoprogenitor cell supply. It could be used to enhance the healing of fractures predisposed to nonunion.

Summary 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 μg 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.

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 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.

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.

PURPOSE: Long-lasting low back pain is an increasing problem, and for some patients surgery is the final option for improvement. Several techniques for spinal fusion are available and the optimal technique remains uncertain. The objective of this study was to assess the cost-effectiveness and cost-utility of transforaminal lumbar interbody fusion (TLIF) compared to posterolateral instrumented fusion (PLF) from the societal perspective.METHODS: 100 Patients were randomized to TLIF or PLF (51/49) and followed for 2 years. Cost data were acquired from national registers, and outcomes were measured using the Oswestry Disability Index and SF-6D questionnaires. Conventional cost-effectiveness methodology was employed to estimate net benefit and to illustrate cost-effectiveness acceptability curves. The statistical analysis was based on means and bootstrapped confidence intervals.RESULTS: Results showed no statistically significant difference in either cost or effects although a tendency for the TLIF regimen being more costly on bed days (2,554) and production loss (1,915) was observed. The probability that TLIF would be cost-effective did not exceed 30 % for any threshold of willingness to pay per quality-adjusted life year. Sensitivity analysis was conducted and supported the statistical model for handling of missing data.CONCLUSION: TLIF does not seem to be a relevant alternative to PLF from a socioeconomic, societal point of view.

STUDY DESIGN: A review of the smoking habits in 426 patients who had been followed prospectively for 2 years after a lumbar spinal fusion procedure was conducted.OBJECTIVE: To analyze the effect of pre- and postoperative smoking on clinical and functional outcome after lumbar spinal fusion.SUMMARY OF BACKGROUND DATA: Several animal models have shown a negative effect of nicotine on spinal fusion. At this writing, the clinical effect of nicotine on spinal fusion has not been fully clarified.METHODS: The study comprised 426 patients who underwent lumbar spinal fusion between 1993 and 1997. These patients received a mailed questionnaire regarding their tobacco consumption before and after their surgery. All other data, including preoperative clinical and functional status, were collected prospectively during a 2-year follow-up period. To assess functional outcome, the Dallas Pain Questionnaire was used.RESULTS: The questionnaire was answered by 396 patients (93%). Of these patients, 54.5% (20% more than the background population) were smokers before the operation. Smoking of more than 10 cigarettes daily before the operation and attempted fusion at two or more levels increased the risk of nonunion: odds ratio, 2.01 (P < 0.016) and odds ratio, 3.03 (P < 0.001), respectively. Smoking cessation increased fusion rates to near those of nonsmokers. Smoking had no influence on functional outcome, as assessed by the Dallas Pain Questionnaire, but preoperative smoking predicted a negative answer to the question "Would you undergo the same treatment again, now that you know the result?" (odds ratio, 1.65; P < 0.054).CONCLUSIONS: Smoking was shown to have a negative effect on fusion and overall patient satisfaction, but no measurable influence on the functional outcome as assessed by the Dallas Pain Questionnaire.

Treatment with corticosteroids is a risk factor for non-traumatic avascular necrosis of the femoral head, but the pathological mechanism is poorly understood. Short-term treatment with high doses of methylprednisolone is used in severe neurotrauma and after kidney and heart transplantation. We investigated the effect of such treatment on the pattern of perfusion of the femoral head and of bone in general in the pig. We allocated 15 immature pigs to treatment with high-dose methylprednisolone (20 mg/kg per day intramuscularly for three days, followed by 10 mg/kg intramuscularly for a further 11 days) and 15 to a control group. Perfusion of the systematically subdivided femoral head, proximal femur, acetabulum, humerus, and soft tissues was determined by the microsphere technique. Blood flow in bone was severely reduced in the steroid-treated group. The reduction of flow affected all the segments and the entire epiphysis of the femoral head. No changes in flow were found in non-osseous tissue. Short-term treatment with high-dose methylprednisolone causes reduction of osseous blood flow which may be the pathogenetic factor in the early stage of steroid-induced osteonecrosis.

Many pathological bone conditions are accompanied by changes in bone perfusion. However, no method has yet allowed investigation of vascular reactivity in human bone tissue. In the present study, arterial segments (diameter approximately 0.25 mm) were isolated from human bone biopsies and mounted as ring preparations in vitro. The viability of the arteries and the effects of adrenoceptor stimulations were investigated. Combined alpha- and beta-adrenoceptor stimulation (noradrenaline 10(-8)-10(-5) M) and specific alpha1-adrenoceptor stimulation (phenylephrine, 10(-8)-10(-4.5) M) induced concentration-dependent contractions in all arteries. Selective stimulation of alpha2-receptors (B-HT 933, 10(-8)-10(-3.5) M) only induced contraction in three of eight arteries. Stimulation of beta-receptors with isoprenaline (10(-6) M) resulted in vasorelaxation in 3 of 10 arteries. In all arteries, acetylcholine (10(-10)-10(-5) M) induced vasorelaxation, demonstrating preserved function of the endothelium. The results suggest that primarily alpha1-receptors are responsible for adrenoceptor induced vasoconstriction in human bone while functional alpha2- and beta-receptors may not be consistently expressed. The model is the first to allow investigations on vascular reactivity in human bone tissue and may become valuable for assessment of both normal and pathological bone physiology.

In a prospective randomized study, we evaluated the risk of lumbar posterolateral spinal fusion at an unintended level due to bone graft migration. 130 patients underwent fusion supplemented by pedicle screw fixation (Cotrell-Dubousset, 64 patients) or uninstrumented fusion (66 patients). This was assessed by two independent observers on antero-posterior, and lateral radiographs taken 1 year after surgery. All patients had ben operated on at the preoperatively planned levels. Both observers agreed that fusion had taken place at an unintended level in 19 cases (14%). We found a tendency towards a higher risk of this "complication" when using supplementary pedicle screw fixation. The functional outcome, assessed by the Dallas Pain Questionnaire and the Low Back Pain Rating scale, was similar in patients having fusion at an unintended level and in patients fused only at the intended levels. There was no difference between the two groups concerning reoperation rates, postoperative smoking or social status. We conclude that unintended fusion occurs and tends to be commoner with the use of pedicle screw instrumentation. However, this complication seems not to affect the functional outcome if fusion has taken place at the intended level.

PURPOSE: To investigate the causes and prevention of distal adding on in Lenke 1A scoliosis.METHODS: Sixty Lenke 1A patients were included. The authors selected 10 potential risk factors for distal adding on. Postoperative increase in 5 radiographic parameters was used to indicate the extent of distal adding on. The authors then performed correlation analysis between the 10 potential risk factors and the extent of distal adding on, with the aim of identifying the causes of distal adding on. To predict 2-year outcome using preoperative parameters, linear regression models were established. The authors selected 2-year Cobb angle, thoracic apical vertebra center sacral vertical line (CSVL) distance and lowest instrumented vertebra (LIV)-CSVL distance to represent 2-year outcome. Their correlations with 8 preoperative parameters were tested.RESULTS: Potential risk factors representing either LIV selection or skeletal immaturity were highly correlated with the 5 radiographic parameters, which suggests that LIV selection and skeletal immaturity are causative in connection with distal adding on. The formula for predicting 2-year LIV-CSVL distance was: 2-year LIV-CSVL distance = 9.9 + 0.8 (preoperative LIV-CSVL distance) - 4.2 (Risser sign grade). The model adjusted R2 = 0.77.CONCLUSIONS: In Lenke 1A scoliosis, both LIV selection and skeletal immaturity are highly correlated with distal adding on. In other words, the shorter the extent is of distal fusion, the larger is the distal adding on; the less skeletally mature the patient is, the larger is the distal adding on. When treating skeletally immature patients (Risser sign ≤3) with 1A curves, performing fusion surgeries should be avoided when possible; growing rod treatment may be the optimal treatment choice. For skeletally mature patients, LIV selection should be the first consideration; the preoperative LIV-CSVL distance should be ≤21 mm when the Risser sign grade is 4 and ≤ 26 mm when the Risser sign grade is 5.

The capacity of the individual patient to initiate osteoblast proliferation as a predictor for successful lumbar spinal fusion has not yet been reported. The objectives of this study were, first, to analyze the relationship between in vitro osteoblast proliferation and clinical bony fusion in the individual patient in order to predict the fusion outcome and, second, to measure the effect of preoperative tobacco smoking on osteoblast proliferation. Sixty-one patients (mean age 46 years) underwent posterolateral lumbar fusion in the period 1994-1995. Thirty-eight patients received CD pedicle screw implants and 23 received posterolateral fusions alone. During surgery, autogenous iliac bone was harvested and 1 g of trabecular bone without blood or bone marrow was then isolated for cell culturing. The cultures were classified as excellent (confluence within 4 weeks), good (confluence between 4 and 6 weeks) and poor (no or poor growth). Spine fusion was evaluated by two independent observers from plain anterior- posterior, lateral, and flexion/extension radiographs taken 1 year postoperatively, and the functional outcome was measured by the Dallas Pain Questionnaire (DPQ). Twenty-three patients had excellent, 19 good, and 19 poor in vitro osteoblast proliferation. Bony fusion was obtained in 77% of patients: 83% in the CD instrumentation group and 70% in the non- instrumentation group (NS). There was no significant correlation between osteoblast proliferation and spinal fusion or functional outcomes when analyzing the CD instrumentation and non-instrumentation groups together or separately. Elderly patients had a significantly poorer osteoblast proliferation than younger patients (P < 0.008). Preoperative tobacco consumption had no discernible effect on osteoblast proliferation, and no correlation between smoking and fusion was found. Further refinement of autologous osteoblast culturing may provide a biological tool for selection of patients who require biological enhancement of their bone fusion capacity. The poorer osteoblast proliferation related to advanced age supports the important negative biological influence of age on bony fusion. However, with more sensitive testing and better discrimination, other results are possible - or can in any event not be excluded.

STUDY DESIGN A prospective randomized clinical study. OBJECTIVES To evaluate supplementary pedicle screw fixation (Cotrel-Dubousset) in posterolateral lumbar spinal fusion. SUMMARY OF BACKGROUND DATA The rationale behind lumbar fusion is to eliminate pathologic motion to relieve pain. To improve fusion rates and to allow reduction, a rigid transpedicular screw fixation may be beneficial, but the positive effect of this may be counter-balanced by an increase in complications. METHODS The inclusion criteria were severe, chronic low back pain from spondylolisthesis Grades 1 and 2 or from primary or secondary degenerative segmental instability. One hundred thirty patients were randomly allocated to receive no instrumentation (n = 66) or Cotrel-Dubousset instrumentation (n = 64) in posterolateral lumbar fusion. Variables were registered at the time of surgery and at 1 and 2 years after surgery. RESULTS Follow-up was achieved in 97.7% of the patients. Fusion rates deduced from plain radiographs were not significantly different between instrumented and noninstrumented groups. The functional outcome assessed by the Dallas Pain Questionnaire improved significantly in both groups, and there were no significant differences in results between the two groups, except for significantly better (P < 0.06) functional outcome in relation to daily activities in the instrumented group when neural decompression had been performed. The global patients' satisfaction was 82% in the instrumented group versus 74% in the noninstrumented group (not significant). Fixation of instrumentation increased operation time, blood loss, and early reoperation rate significantly. Patients experienced only a few minor postoperative complications; none were major. Two infections appeared in the Cotrel-Dubousset group. Significant symptoms from misplacement of pedicle screws were seen in 4.8% of the instrumented patients. CONCLUSIONS Lumbar posterolateral fusion with pedicle screw fixation increases the operation time, blood loss, and reoperation rate, and leads to a significant risk of nerve injury. The functional outcome improves significantly with high patient satisfaction, with or without instrumentation. No significant differences were observed between the two groups in functional outcome and fusion rate. The only gain in functional outcome from instrumentation was found in the daily activity category in patients with supplementary neural decompression. The results of this study do not justify the general use of pedicle screw fixation alone as an adjunct to posterolateral lumbar fusion.

PURPOSE: To examine correlation between postoperative radiographic and cosmetic improvements in Lenke 1C adolescent idiopathic scoliosis (AIS) with patients' self-rated outcomes of health and disability at follow-up as determined by the Scoliosis Research Society questionnaire (SRS-30), Oswestry Disability Index score (ODI) and measure of overall health quality Euroqol-5d (EQ-5D).METHODS: 24 Lenke 1C scoliosis patients, mean age 16.5 (12.8-38.1) years, treated with posterior pedicle screw-only construct, were included. The coronal profile indices (radiographic and cosmetic) regarding magnitude of spinal deformity and truncal balance were measured preoperatively, postoperatively and at final follow-up. A comprehensive index of overall back symmetry was also measured by means of the Posterior Trunk Symmetry Index (POTSI). Pearson's correlation analysis determined the association between the radiographic-cosmetic indices and patient-rated outcomes.RESULTS: Mean follow-up for the cohort was 4.4 (±1.86) years. The thoracic apical vertebra-first thoracic vertebra horizontal distance (AV-TI) correction had significant correlation with function, self-image, and mental health SRS-30 scores (0.55, 0.54, 0.66). Similarly, thoracic apical vertebra horizontal translation from central sacral vertical line (AV-CSVL) correction at follow-up had significant correlation with self-image and management domains (0.57, 0.50). Follow-up POTSI correlated well with SRS-30 and EQ-5D scores (r = -0.64, -0.54). Postoperative leftward trunk shift/spinal imbalance did not influence overall cosmesis and outcomes; significant spinal realignment was evident in follow-up resulting in physiological balance and acceptable cosmesis and outcomes.CONCLUSION: Significant, but less than "perfect" correlations were observed between the radiographic, cosmetic measures and patient-rated outcomes. Thoracic AV-CSVL, AV-T1 correction and POTSI associated significantly with SRS-30 scores. Whereas, thoracic Cobb angle, Cobb correction, and coronal balance did not correlate with any patient-rated outcome measure. It is, therefore, inferred that the patients-rated subjective outcomes are only poorly reflected by the objectively measured radiographic and cosmetic measures of deformity correction.

Study design A radiographical follow-up and analysis. Objective To investigate the postoperative curve change in Lenke 5C scoliosis, and to discuss how to select lowest instrumented vertebra (LIV). Summary of background data 5C curves are relatively rare in adolescent idiopathic scoliosis, and few studies have focused on this type of adolescent idiopathic scoliosis. Such questions as "How does the curve change over time in the postoperative period?" "Is LIV selection correlated with final correction and balance?" and "How should we select LIV for Lenke 5C curves?" need to be answered. Methods We reviewed all the adolescent idiopathic scoliosis cases surgically treated in an institution from 2002 through 2008. Inclusion criteria were as follows: (1) patients with Lenke 5C curves who were treated with selective lumbar fusion; (2) minimum 2-year radiographical follow-up.All image data were available and all measurements were performed in picture archiving and communication systems. Standing posteroanterior and lateral digital radiographs were reviewed at 4 junctures: preoperative, immediate postoperative, 3 months, and 2 years postoperatively. Results Thirty patients met the inclusion criteria. The following results were observed: (1) From the perspectives of both Cobb angle and vertebral translation, significant correction was achieved; (2) The correction obtained by surgery was well retained in the postoperative period; (3) Although preoperative spinal imbalance was common in this group of patients, the majority eventually attained balance at 2 years; (4) LIV selection was significantly correlated with the 2-year correction and balance; (5) In the literature as well as in this study, the overall preoperative LIV-center sacral vertical line distance is 28 mm and the overall preoperative LIV tilt is 25°. Conclusion In Lenke 5C scoliosis, preoperative spinal imbalance is common, although the majority of patients attain balance at 2 years. Significant correction loss is not common in the postoperative period. LIV selection significantly correlates with 2-year correction and balance. A translation of 28 mm and a tilt of 25° may be used as a general criterion for selecting LIV. Level of evidence 2.

Knowledge about vascular regulation in bone is central to the understanding of both normal and pathological bone physiology. This article describes a new method for direct assessment of the reactivity of bone blood vessels. Resistance arteries (diameter approximately 250 microns) were isolated from epiphyseal cancellous bone (porcine femoral condyle). Arterial segments (2 mm long) were mounted as ring preparations on a myograph, and isometric force development was measured continuously. Fifty-nine vessels from 31 pigs were investigated. The active force development was maximal at 0.9 x L100 in nine of 12 investigated arteries (L100 corresponds to the circumference the vessel would have if relaxed and exposed to a luminal pressure of 100 mm Hg [13.3 kPa]). In all subsequent experiments, the vessels were stretched to 0.9 x L100. Noradrenaline (2 x 10(-8) to 10(-5) M) induced a concentration-dependent vasoconstriction; mean maximal tension development was 3.69 N/m. This force development would enable the arteries to contract against a pressure of more than 22 kPa (165 mm Hg), indicating preserved function of the media smooth muscle. Response to acetylcholine (10(-7) to 10(-5) M) was observed in only two of 12 arteries. Bradykinin (10(-11) to 10(-6) M) induced a concentration-dependent and reproducible relaxation in all vessels; the relaxation was endothelium-dependent, since no effect of bradykinin was detected after mechanical removal of the endothelium. Sodium nitroprusside (10(-4) M) induced a reproducible and endothelium-independent vasorelaxation. The results demonstrate preserved function of both smooth muscle and endothelium in this preparation. The model allows pharmacological investigations of bone arteries under well defined conditions and enables studies on focal bone lesions and human bone tissue.

The role of different loading conditions on resorption of plasma-sprayed hydroxyapatite coating was investigated in an experimental study. Resorption of hydroxyapatite was quantified by histomorphometric and stereological methods on backscattered scanning electron images. Hydroxyapatite-coated titanium implants were inserted unilaterally into the medial femoral condyle of the knee in 14 mature dogs. Initially, all implants were subjected to controlled micromotion of 150 microns. After 4 weeks, the dogs were randomly assigned either to have the implant surgically immobilized to prevent further micromovement or to have a sham operation. Sixteen weeks after the first operation, the implants were analyzed. Six noninserted implants served as controls. The surface area and volume of the hydroxyapatite coating were reduced on the immobilized implants by 53 and 67% (p < 0.05), respectively, and were further significantly reduced on the continuously loaded implants by 83 and 87%, respectively, compared with the control implants. The hydroxyapatite coating was significantly thinner on immobilized (15 microns) and continuously loaded (15 microns) implants as compared with control implants (23 microns), but no difference between the inserted implants was found. Areas not covered with hydroxyapatite had 29 and 24% bone coverage on the immobilized and continuously loaded implants (not significant). Resorption of hydroxyapatite coating did occur in vivo. Continuous loading of the implants accelerated resorption significantly compared with immobilization of the implants. It is suggested that completely resorbed hydroxyapatite was partly replaced by bone in direct contact with the metal implant surface.

Study design A radiographical follow-up and analysis. Objective To identify appropriate radiographical parameters for measuring the extent of distal adding-on and to discuss criteria for determining the onset of distal adding-on. Summary of background data There is no consensus on how to determine the onset of distal adding-on in Lenke 1A scoliosis. Such questions as: "Which radiographical parameters should be used for measuring the extent of distal adding-on?" and "What criteria should be applied in determining the onset of distal adding-on?" need to be answered. Methods We reviewed all the AIS cases surgically treated in an institution from 2003 through 2009. Inclusion criteria were as follows: (1) patients with Lenke 1A curves who were treated with selective thoracic fusion; (2) age less than 30 years; (3) 2-year radiographical follow-up. Eight radiographical parameters were tested to see if they are potential instruments in the detection of distal adding-on. Results Fifty-three patients met the inclusion criteria. No pseudarthrosis or crankshaft phenomenon was observed in the current cohort. Five out of 8 radiographical parameters: thoracic Cobb, LIV-CSVL distance, LIV + 1-CSVL distance, thoracic AV-CSVL distance and LIV + 1 tilt angle, in the 2 years after surgery, showed significant increase. The remaining 3 parameters: LIV tilt angle, T1-CSVL distance and number of vertebrae within Cobb, however, did not show significant increase. In regard to the 5 parameters that have the potential to detect the onset of distal adding-on, we found a high correlation between every 2 of them. The correlation coefficients range from 0.504 to 0.962 (P = 0.001), suggesting that all of them are in a positive linear relationship. Regarding the criterion for determining the onset of distal adding-on, an increase of more than 10 mm in LIV-CSVL distance in the postoperative period can be considered as a the main criterion because it is unlikely to be induced by measurement errors. Conclusion LIV-CSVL distance could be an ideal parameter for measuring the extent of distal adding-on. Distal adding-on can be determined when the LIV-CSVL distance increases by 10 mm in the postoperative period.

PURPOSE AND METHODS: We reviewed the management, failure modes, and outcomes of 196 patients treated for infectious spondylodiscitis between January 1, 2000 and December 31, 2010, at the Spinal Unit, Aarhus University Hospital, Aarhus, Denmark. Patients with infectious spondylodiscitis at the site of previous spinal instrumentation, spinal metastases, and tuberculous and fungal spondylodiscitis were excluded. RESULTS: Mean age at the time of treatment was 59 (range 1-89) years. The most frequently isolated microorganism was Staphylococcus aureus. The lumbosacral spine was affected in 64 % of patients and the thoracic in 21 %. In 24 % of patients, there were neurologic compromise, four had the cauda equina syndrome and ten patients were paraplegic. Ninety-one patients were managed conservatively. Treatment failed in 12 cases, 7 patients required re-admission, 3 in-hospital deaths occurred, and 5 patients died during follow-up. Posterior debridement with pedicle screw instrumentation was performed in 75, without instrumentation in 19 cases. Seven patients underwent anterior debridement alone, and in 16 cases, anterior debridement was combined with pedicle screw instrumentation, one of which was a two-stage procedure. Re-operation took place in 12 patients during the same hospitalization and in a further 12 during follow-up. Two in-hospital deaths occurred, and five patients died during follow-up. Patients were followed for 1 year after treatment. Eight (9 %) patients treated conservatively had a mild degree of back pain, and one (1 %) patient presented with mild muscular weakness. Among surgically treated patients, 12 (10 %) had only mild neurological impairment, one foot drop, one cauda equine dysfunction, but 4 were paraplegic. Twenty-seven (23 %) complained of varying degrees of back pain. CONCLUSIONS: Conservative measures are safe and effective for carefully selected patients without spondylodiscitic complications. Failure of conservative therapy requires surgery that can guarantee thorough debridement, decompression, restoration of spinal alignment, and correction of instability. Surgeons should master various techniques to achieve adequate debridement, and pedicle screw instrumentation may safely be used if needed.

The aim of the present study was to analyze outcome, with respect to functional disability, pain, fusion rate, and complications of patients treated with transforaminal lumbar interbody fusion (TLIF) in compared to instrumented poserolateral fusion (PLF) alone, in low back pain. Spinal fusion has become a major procedure worldwide. However, conflicting results exist. Theoretical circumferential fusion could improve functional outcome. However, the theoretical advantages lack scientific documentation. Prospective randomized clinical study with a 2-year follow-up period. From November 2003 to November 2008 100 patients with severe low back pain and radicular pain were randomly selected for either posterolateral lumbar fusion [titanium TSRH (Medtronic)] or transforaminal lumbar interbody fusion [titanium TSRH (Medtronic)] with anterior intervertebral support by tantalum cage (Implex/Zimmer). The primary outcome scores were obtained using Dallas Pain Questionnaire (DPQ), Oswestry disability Index, SF-36, and low back pain Rating Scale. All measures assessed the endpoints at 2-year follow-up after surgery. The overall follow-up rate was 94 %. Sex ratio was 40/58. 51 patients had TLIF, 47 PLF. Mean age 49(TLIF)/45(PLF). No statistic difference in outcome between groups could be detected concerning daily activity, work leisure, anxiety/depression or social interest. We found no statistic difference concerning back pain or leg pain. In both the TLIF and the PLF groups the patients had significant improvement in functional outcome, back pain, and leg pain compared to preoperatively. Operation time and blood loss in the TLIF group were significantly higher than in the PLF group (p

PURPOSE: Our objectives were primarily to review the published literature on complications in neuromuscular scoliosis (NMS) surgery and secondarily, by means of a meta-analysis, to determine the overall pooled rates (PR) of various complications associated with NMS surgery.METHODS: PubMed and Embase databases were searched for studies reporting the outcomes and complications of NMS surgery, published from 1997 to May 2011. We focused on NMS as defined by the Scoliosis Research Society's classification. We measured the pooled estimate of the overall complication rates (PR) using a random effects meta-analytic model. This model considers both intra- and inter-study variation in calculating PR.RESULTS: Systematic review and meta-analysis were performed for 68 cohort and case-control studies with a total of 15,218 NMS patients. Pulmonary complications were the most reported (PR = 22.71 %) followed by implant complications (PR = 12.51 %), infections (PR = 10.91 %), neurological complications (PR = 3.01 %) and pseudoarthrosis (PR = 1.88 %). Revision, removal and extension of implant had highest PR (7.87 %) followed by malplacement of the pedicle screws (4.81 %). Rates of individual studies have moderate to high variability. The studies were heterogeneous in methodology and outcome types, which are plausible explanations for the variability; sensitivity analysis with respect to age at surgery, sample size, publication year and diagnosis could also partly explain this variability. In regard to surgical complications affiliated with various surgical techniques in NMS, the level of evidence of published literature ranges between 2+ to 2-; the subsequent recommendations are level C.CONCLUSION: NMS patients have diverse and high complication rates after scoliosis surgery. High PRs of complications warrant more attention from the surgical community. Although the PR of all complications are affected by heterogeneity, they nevertheless provide valuable insights into the impact of methodological settings (sample size), patient characteristics (age at surgery), and continual advances in patient care on complication rates.

We conducted a prospective cohort study of 448 patients with spinal metastases from a variety of cancer groups.To determine the specific predictive value of the Tokuhashi scoring system (T12) and its revised version (T15) in spinal metastases of various primary tumors.The life expectancy of patients with spinal metastases is one of the most important factors in selecting the treatment modality. Tokuhashi et al formulated a prognostic scoring system with a total sum of 12 points for preoperative prediction of life expectancy in 1990 and revised it in 2005 to a total sum of 15 points. There is a lack of knowledge about the specific predictive value of those scoring systems in patients with spinal metastases from a variety of cancer groups.We included 448 patients with vertebral metastases who underwent surgical treatment during November 1992 to November 2009 in Aarhus University Hospital NBG. Data were retrieved from Aarhus Metastases Database. Scores based on T12 and T15 were calculated prospectively for each patient. We divided all the patients into different groups dictated by the site of their primary tumor. Predictive value and accuracy rate of the 2 scoring systems were compared in each cancer group.Both the T12 and T15 scoring systems showed statistically significant predictive value when the 448 patients were analyzed in total (T12, P0.0001; T15, P0.0001). The accuracy rate was significantly higher in T15 (P0.0001) than in T12. The further analyses by primary cancer groups showed that the predictive value of T12 and T15 was primarily determined by the prostate (P = 0.0003) and breast group (P = 0.0385). Only T12 displayed predictive value in the colon group (P = 0.0011). Neither of the scoring systems showed significant predictive value in the lung (P0.05), renal (P0.05), or miscellaneous primary tumor groups (P0.05). The accuracy rate of prognosis in T15 was significantly improved in the prostate (P = 0.0032) and breast group (P0.0001).Both T12 and T15 showed significant predictive value in patients with spinal metastases. T15 has a statistically higher accuracy rate than T12. Among the various cancer groups, the 2 scoring systems are especially reliable in prostate and breast metastases groups. T15 is recommended as superior to T12 because of its higher accuracy rate.

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.

Endothelin (ET) provokes strong and sustained contraction in preparations of isolated vascular smooth muscle, and the production of ET is thought to increase secondary to increased wall shear stress and hypoxia. The release of ET and blood flow distribution between arteriovenous shunts and capillaries were studied in autoperfused myocutaneous pig island flaps during graded arterial or venous blood flow reduction (N = 12). A group comprising four flaps was not exposed to blood flow reduction and served as controls. Total flap blood flow (venous outflow [VO]) was reduced in 1-hour periods to 50%, 25%, and 0%. Downregulation of VO caused a lower capillary blood flow (CBF) at 25% (P < .05) and at 50% (P < .05) in flaps exposed to venous stasis as compared with flaps with arterial ischemia. The reduction in blood flow was paralleled by decreasing oxygen consumption, although flaps with venous stasis had lower oxygen consumption than flaps exposed to arterial ischemia (P < .05). ET was found to be released from these island flaps before blood flow was reduced. Gradual arterial clamping caused a statistically significant (P < .05) decrease in the release of ET from 8.7 ± 1.3 fmol/min before ischemia to 4.1 ± 1.7 at 50% blood flow and 4.1 ± 1.0 at 25% blood flow. In contrast, the release of ET with venous stasis remained unchanged at a level of 7.5 ± 1.6 fmol/min before blood flow reduction, 7.3 ± 0.7 at 50% blood flow, and 8.5 ± 1.6 at 25% blood flow. These data suggest a relationship between CBF, intravascular pressure, and ET production. Determining whether intravascular pressure or hypoxia are the reasons for maintained ET release in response to venous stasis or whether a persistently high ET release during venous stasis causes reductions in CBF requires further study.

STUDY DESIGN Retrospective study. OBJECTIVE To identify risk factors for the presence of distal adding-on in Lenke 1A scoliosis and compare different treatment strategies. SUMMARY OF BACKGROUND DATA Distal adding-on is often accompanied by unsatisfactory clinical outcome and high risk of reoperation. However, very few studies have focused on distal adding-on and its attendant risk factors and optimal treatment strategies remain controversial. METHODS All surgically treated patients with adolescent idiopathic scoliosis were retrieved from a single institutional database. Inclusion criteria included: (1) Lenke 1A scoliosis patients treated with posterior pedicle screw-only constructs, (2) minimum 1-year radiographic follow-up. Distal adding-on was defined as a progressive increase in the number of vertebrae included distally within the primary curve combined with either an increase of more than 5 mm in deviation of the first vertebra below instrumentation from the center sacral vertical line (CSVL), or an increase of more than 5° in the angulation of the first disc below the instrumentation at 1 year follow-up. Wilcoxon rank sum test, Fisher exact test, and Spearman correlation test were used to identify the risk factors for adding-on. A multiple logistic regression model was built to identify independent predictive factor(s). Risk factors included: (1) age at surgery; (2) preoperative Cobb angle; (3) correction rate; (4) the gap difference of stable vertebra-lowest instrumented vertebra (SV-LIV), neutral vertebra-lowest instrumented vertebra (NV-LIV), and end vertebra-lowest instrumented vertebra (EV-LIV). Gap difference means, for example, if SV is at L2 and LIV is at Th12, then the difference of SV-LIV is 2; (5) the preoperative deviation of LIV+1 (the first vertebra below the instrumentation) from the CSVL (the vertical line that bisects proximal sacrum). Five methods for determining LIV were compared in both the adding-on group and no adding-on group. RESULTS Out of the 278 patients reviewed, 45 met the inclusion criteria; 23 of these met the definition for distal adding-on, and were included in the adding-on group. The remaining 22 patients were included in the no adding-on group. The average follow-up was 3.6 years. Age, SV-LIV difference, EV-LIV difference, and LIV+1 deviation from CSVL were significantly different (P

We allocated randomly 27 patients undergoing 28 primary uncemented total hip replacements (THR) to receive prosthetic components of similar design with either plasma-sprayed titanium alloy (Ti) coating (n = 13) or hydroxyapatite (HA) coating (n = 15). After some exclusions, 15 of the patients (15 THR; 7 with HA- and 8 with Ti-coating) were followed by roentgen stereophotogrammetric analysis at 3, 6 and 12 months to measure migration of the femoral component. Twenty-six of the patients (26 THR) were followed clinically and by conventional radiography. All the femoral components had migrated at 3 months. From 3 to 12 months, the migration of Ti-coated components continued whereas the HA-coated components had stabilised. At 12 months there was significantly less migration of the HA-coated components (p < 0.05). The maximum subsidence was 0.2 mm in both groups. The Harris hip score was equal in the two groups preoperatively but at follow-up it was better in the HA-coated group (p < 0.05) and visual analogue scale scores showed that they had less pain (p < 0.05).

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.

The impact of naproxen treatment on juxta-articular hemodynamics and bone metabolism in experimental juvenile arthritis was studied in the articular carrageenan injection model. Unilateral gonarthritis was induced for 12 weeks in eight dogs receiving naproxen (dosage, 2 mg/kg) and eight controls. Regional blood flow was assessed by the microsphere method, plasma volume by the distribution space of [125I]fibrinogen, and bone metabolism by the 2-h uptake of [99mTc]diphosphonate ([99mTc]DPD). Synovial effusion was less prominent with naproxen treatment as judged by joint fluid volume and pressure. Naproxen reduced the arthritic capsular hyperemia, almost normalized a severe blood flow increase in patella and both juxta-articular epiphyses, ameliorated an expansion of plasma volume in the patella and the distal femoral epiphysis, and normalized an increased [99mTc]DPD uptake in subchondral femoral bone and the tibial cortex. Significantly increased arteriovenous shunting in the arthritic extremity was unaffected by naproxen. The study suggests that long-term cyclooxygenase inhibition offers protection against hemodynamic and metabolic changes in juxta-articular bone secondary to synovial inflammation.

To further clarify the pathogenesis of the poorer prognosis in skin flaps exposed to venous stasis compared with arterial insufficiency, a microsphere study was conducted in bilateral rectus abdominis island flaps in seven pigs. The relationship between capillary blood flow and arteriovenous (A-V) shunting was studied during progressive 1-hour intervals of arterial insufficiency and venous stasis and during 3 hours of reperfusion. Under controlled conditions, total blood flow was reduced from 100 percent to both 50 and 25 percent by application of an adjustable clamp on the artery supplying one flap and on the vein draining the contralateral flap. The relative distribution between A-V shunt flow and capillary blood flow was different in arterial insufficiency when compared with venous stasis at both the 50 percent and the 25 percent blood flow levels. In the arterial insufficiency flaps, the A-V shunt flow and capillary blood flow shared the total blood flow in the following percentages: 64/36 (at 100 percent total blood flow), 44/56 (at 50 percent total blood flow level), and 22/78 (at 25 percent total blood flow level). In the venous stasis flaps, the A-V shunt flow and the capillary blood flow shared the total blood flow in percentages of 70/30, 66/34, and 55/45, respectively. Hence, in arterial insufficiency flaps, capillary blood flow was spared by a relatively greater decline in A-V shunting compared with venous stasis flaps. Redistribution of capillary blood flow from subcutaneous tissue to muscle was observed, whereas blood flow was equally distributed throughout the length of the flaps at all flow levels.(ABSTRACT TRUNCATED AT 250 WORDS)