Does the interfacing angle between pedicle screws and support rods affect clinical outcomes after posterior thoracolumbar fusion? A retrospective clinical study.

BACKGROUND CONTEXT: Proper alignment and tightening of the pedicle screw/rod assembly after instrumented posterior fusion of the lower spine is known to be crucial in order to achieve satisfactory clinical results. Such interfacing angle mismatches indicate stress overloading of the implant system. PURPOSE: The objective of this study is to investigate the incidence of postoperative screw/rod interfacing angle mismatch and to analyze the impact of mismatches on clinical outcome in terms of (1) revision surgery, (2) adjacent segment degeneration (ASD), and (3) pain. STUDY DESIGN: This is a monocentric retrospective observational study. PATIENT SAMPLE: Patients underwent fusion surgery with pedicle screw/rod systems for predominantly degenerative pathologies. OUTCOME MEASURES: Pedicle screw/rod interfacing angle mismatch (mismatch is the angular deviation from 90° formed by the rod axis and the pedicle screw head axis as an indicator for missing form-fit) revision rate, ASD at the immediately adjacent cranial segment and VAS pain. METHODS: Revision refers to subsequent procedures in which all or part of the original implant configuration is changed or removed. Radiographic parameters are evaluated using a/p and lateral radiographs at final follow-up. The interfacing angle mismatch between pedicle screw and rod is measured as the angle between two parallel lines on either side of each pedicle screw head and a line laterally along the associated rod. Multiple comparisons are counteracted by Bonferroni correction, adjusted significance level is at *p<.01. RESULTS: Pedicle screw and rod interfacing angle mismatch was found in 171/406 (42.1%) of patients undergoing fusion surgery, affecting 613/3016 (20.3%) screws. The overall revision incidence was 11.8% (48/406), and a new ASD occurred in 12.1% of all patients (49/406) with an average follow-up of 5 years. Mean VAS pain score at final follow-up was 2.0. Comparison of the two groups with and without mismatches revealed statistically significantly higher (1) numbers of revision procedures performed (26.9% vs 0.9%), (2) numbers of new ASD developed (27.5% vs 3.8%), and (3) higher VAS pain scores (2.8/10 vs 1.4/10) for cases with mismatch. When comparing patients who underwent intraoperative correction and/or reduction with those who did not, statistically significant more screw mismatches (63.4% vs 39.7%) and revision surgeries (29.3% vs 9.9%) were noted in patients who had these forceful maneuvers. CONCLUSIONS: Pedicle screw/rod interfacing angle mismatch is a frequent occurrence after fusion surgery. Mismatches indicate that the construct was assembled under mechanical stress. All preventable mechanical stresses, for example, unintentional uncontrolled forces on the instrumentation, should be avoided as much as possible, as they can negatively influence the clinical outcome.

Effectiveness of Mud-Pack Therapy and Mud-Bath Therapy in Osteoarthritis: A Systematic Review.

OBJECTIVES: Osteoarthritis has a tremendous socioeconomic impact in terms of drug spending, hospital admissions, work productivity, and temporary or permanent incapacity. Mud therapy has been discussed as potential conservative treatment options for osteoarthritis. However, findings from several trials still remain controversial. For this reason, we aimed to systematically review the highest evidence provided by published trials to estimate the clinical effect of mud-pack and mud-bath therapy for the treatment of osteoarthritis. METHODS: We searched PubMed, PEDro, and the Cochrane CENTRAL Register for Controlled Trials for articles published between 2000 and 2020 using the terms "orthopedics," "orthopaedics," "musculoskeletal," "osteoarthritis," and "mud bath," "mud pack." RESULTS: Of the 19 studies included, 15 examined the effects of mud-bath therapy in knee osteoarthritis treatment. One study focused on the treatment effect of mud bath on hand osteoarthritis, another study examined treatment effects in hip and knee osteoarthritis, and two studies enrolled patients with chronic low back pain caused by lumbar spine osteoarthritis. We systematically reviewed the data obtained from the literature and summarized the results on the basis of the main outcomes. The results show significant improvements in function, quality of life, and perceived pain for patients with osteoarthritis. CONCLUSION: Results of randomized controlled trials suggest that mud therapy is part of a promising integrated and synergistic multidisciplinary approach in combination with other treatment forms like pharmacotherapy or physiotherapy.Die sozio-ökonomischen Auswirkungen der Arthrose sind immens. Heiltorfbehandlungen sind seit einiger Zeit als mögliche Ergänzung der konservativen Therapieoptionen dieser Erkrankung Gegenstand wissenschaftlicher Untersuchungen. Ziel dieser Studie war es, die aktuellen Erkenntnisse zur Heiltorftherapie bei Arthrose zusammenzufassen.Wir führten eine systematische Literaturrecherche der Datenbanken Pubmed, PEDro und Cochrane CENTRAL Register of Controlled Trials durch. Hierbei wurden Artikel, die zwischen 2000 und 2020 publiziert wurden und mit den Schlagwörtern "orthopedics", "orthopaedics", "musculoskeletal", "osteoarthritis" und "mud-bath", "mud-pack" assoziiert waren, erfasst.Von den 19 näher untersuchten Studien beschäftigten sich 15 mit den Effekten der Heiltorftherapie bei Patienten mit Kniearthrose, eine Studie untersuchte Patienten mit Arthrose der Hand, eine weitere Studie untersuchte die Auswirkung der Therapie bei Arthrose der Hüfte. 2 Studien untersuchten den Effekt der Moorbäder bei Patienten mit chronischen Rückenschmerzen. Insgesamt zeigten sich signifikante Verbesserungen der Funktion, Lebensqualität und Schmerzlinderung bei den Patienten unter Heiltorftherapie.Die Ergebnisse der randomisierten, kontrollierten Studien zeigen, dass die Heiltorftherapie eine vielversprechende Ergänzung in einem multidisziplinären Ansatz der Arthrosetherapie ist.

Bony hip reconstruction for displaced hips in patients with cerebral palsy: Is postoperative immobilization indicated?

Purpose: Decisions for postoperative immobilization after bony hip reconstructive surgery in cerebral palsy are controversial in current practice. The aim of this study was to check if choosing not to use any kind of postoperative immobilization is a safe practice. Methods: A retrospective cohort study was conducted in a pediatric orthopedic tertiary referral center. The study included 148 patients (228 hips) with cerebral palsy, who had bony hip surgery. Medical records were reviewed for incidence of complications, methods of pain control, and length of hospital stay. Three radiographic measures (neck-shaft angle, Reimers migration index, and acetabular index) were performed on preoperative and postoperative X-rays. X-rays were also checked for mechanical failure of implant, recurrent dislocation/subluxation, and fractures in the first 6 months postoperatively. Results: In total, 94 (64%) were male and 54 (36%) were female. Seventy-seven (52%) were Gross Motor Function Classification System V, mean age at surgery was 8.6 years (2.5-18.4 years). Length of hospital stay was 6.25 days (SD 4.64 days). Medical complications that may have prolonged hospital stay occurred in 41 patients (27.7%). Radiological measurements showed significant improvement postoperatively (p = 0.001). Seven patients (4.7%) had another surgery in first 6 months (three for recurrent dislocation/subluxation, three for implant failure, and one for ipsilateral femur fracture). Conclusion: Avoiding postoperative immobilization following bony hip surgery in cerebral palsy is a safe practice and associated with reduced rate of medical and mechanical problems compared to the current literature. This approach should be utilized with optimal pain and tone management.

Measuring hip migration percentage in cerebral palsy using the HipScreen app.

Aims: Reimers migration percentage (MP) is a key measure to inform decision-making around the management of hip displacement in cerebral palsy (CP). The aim of this study is to assess validity and inter- and intra-rater reliability of a novel method of measuring MP using a smart phone app (HipScreen (HS) app). Methods: A total of 20 pelvis radiographs (40 hips) were used to measure MP by using the HS app. Measurements were performed by five different members of the multidisciplinary team, with varying levels of expertise in MP measurement. The same measurements were repeated two weeks later. A senior orthopaedic surgeon measured the MP on picture archiving and communication system (PACS) as the gold standard and repeated the measurements using HS app. Pearson's correlation coefficient (r) was used to compare PACS measurements and all HS app measurements and assess validity. Intraclass correlation coefficient (ICC) was used to assess intra- and inter-rater reliability. Results: All HS app measurements (from 5 raters at week 0 and week 2 and PACS rater) showed highly significant correlation with the PACS measurements (p < 0.001). Pearson's correlation coefficient (r) was constantly over 0.9, suggesting high validity. Correlation of all HS app measures from different raters to each other was significant with r > 0.874 and p < 0.001, which also confirms high validity. Both inter- and intra-rater reliability were excellent with ICC > 0.9. In a 95% confidence interval for repeated measurements, the deviation of each specific measurement was less than 4% MP for single measurer and 5% for different measurers. Conclusion: The HS app provides a valid method to measure hip MP in CP, with excellent inter- and intra-rater reliability across different medical and allied health specialties. This can be used in hip surveillance programmes by interdisciplinary measurers.

Retrospective Comparison of Minimally Invasive and Open Monosegmental Lumbar Fusion, and Impact of Virtual Reality on Surgical Planning and Strategy.

BACKGROUND AND STUDY AIMS: Spinal fusion for symptomatic lumbar spondylolisthesis can be accomplished using an open or minimally invasive surgical (MIS) technique. Evaluation of segmental spondylolisthesis and instabilities and review of their therapies are inseparably connected with lumbar tomographic imaging. We analyzed a cohort of patients who underwent MIS or open monosegmental dorsal fusion and compared surgical outcomes along with complication rates. We furthermore evaluated the influence of virtual reality (VR) visualization on surgical planning in lumbar fusion. MATERIAL AND METHODS: Patient files were retrospectively analyzed regarding patient- and disease-related data, operative performance, surgical outcomes, and perioperative surgical complications. Preoperative computed tomography (CT) and magnetic resonance imaging (MRI) scans were retrospectively visualized via VR software. A questionnaire evaluated the influence of three-dimensional (3D) VR images versus two-dimensional CT and MRI scans on therapy planning, fusion method, and surgical technique and procedure. RESULTS: Overall, 171 patients were included (MIS/open: 90/81). MIS was associated with less blood loss, shorter surgery time and hospital stay, lower complication rates, equivalent long-term patient-reported outcomes, but lower fusion rates and higher late reoperation rates than open surgery. Image presentation using VR significantly influenced the recommended surgical therapies (decompression only/decompression and fusion; p = 0.02), had no significant influence on the recommended fusion method (rigid/dynamic/stand-alone; p = 0.77), and, in cases of rigid fusion, a significant influence on the recommended technique (MIS/open; p = 0.03) and fusion procedure (p = 0.02). CONCLUSION: In patients with monosegmental degenerative or isthmic spondylolisthesis, MIS fusion was advantageous concerning perioperative complication rates and perioperative surgical outcomes, but disadvantageous regarding fusion and reoperation rates compared to open fusion. 3D-VR-based analysis of sectional images significantly influenced the recommended surgical planning.

Comparison of stand-alone cage and cage-with-plate for monosegmental cervical fusion and impact of virtual reality in evaluating surgical results.

OBJECTIVES: After ventral decompression of monosegmental cervical spondylotic stenosis, a stand-alone cage (SC) or cage-with-plate (CP) can be inserted for fusion. Postoperative radiological evaluation can be achieved using different imaging modalities. We retrospectively compared complications, as well as clinical and radiological outcomes for both fusion techniques, and analyzed the possible role of virtual reality (VR) in evaluating the postoperative results. PATIENTS AND METHODS: One hundred seventeen patients were included (SC/CP: 54/63). Complications, as well as clinical and radiological outcomes of both fusion techniques were compared. Computed tomography (CT) scans were visualized via VR to measure the smallest cross-sectional area of the intervertebral neuroforamen in the lateral resection region, and to assess the degree of the intersegmental ossification. RESULTS: There were no significant differences between the two fusion techniques regarding perioperative complication rates, fusion rates, or pain parameter (visual analogue scale (VAS) of arm pain, neck disability index). However, advantages regarding subsidence, kyphosis, and VAS of neck pain were found when using the CP versus SC. Using the VR technique, there was no significant difference between the two fusion techniques in the mean size of the cross-sectional area at the end of follow-up. CONCLUSION: Due to the long-term advantages of CP fusion, we prefer a monosegmental cervical spinal fusion using CP. Reconstruction of postsurgical two-dimensional CT images into three-dimensional images, and the spatial and anatomical presentation in VR models, improved the evaluation of these postoperative results.

Association between intervertebral disc degeneration and the Oswestry Disability Index.

BACKGROUND: Low back pain and lumbar intervertebral disc degeneration (IDD) are common findings. Valid data on correlation between clinical pain scores and grades of IDD are not available. OBJECTIVE: To investigate the correlation of intervertebral disc degeneration (IDD) at lumbar levels L4/5 and L5/S1 and the Oswestry Disability Index (ODI). METHODS: The lumbar discs L4/5 and L5/S1 of 591 patients were evaluated according to the 5-point (Grade I to Grade V) grading system as published by Pfirrmann et al. Functional status was assessed using the Oswestry Disability Index. Spearman's coefficient of rank correlation was used for statistical analysis (p < 0.05). RESULTS: The majority of patients revealed lumbar discs with Pfirrmann grade II to grade IV changes (93.3% at level L4/5; 89.8% at level L5/S1), while a relatively low percentage of lumbar discs presented with grade I (level L4/5: 1.5%; level L5/S1: 2.0%) or grade V (level L4/5: 5.1%; level L5/S1: 8.1%) changes, respectively. Patients' ODI scores ranged between 0 and 91.11% (arithmetic mean of 32.77% ± 17.02%). The largest group of patients (48.39%) had moderate functional disability (ODI score between 21 and 40%). There was a weak, but statistically significant positive correlation between IDD and ODI for both evaluated lumbar levels. CONCLUSIONS: Increased lumbar IDD in MRI goes along with an increased ODI. Thus, MRI is a strong indicator of a patient's clinical appearance. However, low back pain cannot be explained by imaging alone. Clinical correlation is imperative for an adequate diagnostic advance in patients with low back pain.

Expression of NO Synthase Under Medication with Cyclosporine A, Mycophenolate Mofetil, and Tacrolimus during Development of Transplant Vasculopathy on Rat Cardiac Allograft.

OBJECTIVE: The transplant vasculopathy as a sign of chronic graft rejection affects both the epicardial and the intramyocardial arteries of the graft. This is at least partially mediated by NO synthases. The aim of this study was to assess possible protective effects of cyclosporine A (CsA), tacrolimus (FK506), and mycophenolate mofetil (MMF) on the expression of NO synthases in an experimental transplant rat model. AIMS: Heart transplantation was performed in 322 rats. These were randomly assigned to four equal groups (control, CsA, FK506, MMF). Recipients were monitored up to 60 days after transplantation, while transplanted hearts were recovered at certain time points for analysis. Expression and staining intensity for endothelial nitric oxide synthases (e-nos) and inducible nitric oxide synthases (i-nos) were analyzed in epicardial and intramyocardial vessels in each group. RESULTS: All employed drugs led to a significant reduction of expression or staining intensity of i-nos and e-nos. MMF was most effective in reduction in expression of both NO synthases. CONCLUSIONS: These results imply that all described drugs prevent endothelial impairment induced by toxicity of NO and thereby prevent transplant vasculopathy. MMF seems to be the most effective drug.

Axial pullout strength comparison of different screw designs: fenestrated screw, dual outer diameter screw and standard pedicle screw.

BACKGROUND: The pullout strength of pedicle screws is influenced by many factors, including diameter of the screws, implant design, and augmentation with bone cement such as PMMA. In the present study, the pullout strength of an innovative fenestrated screw augmented with PMMA was investigated and was compared to unaugmented fenestrated, standard and dual outer diameter screw. METHODS: Twenty four thoracolumbar vertebrae (T10-L5, age 60 to 70 years) from three cadavers were implanted with the four different pedicle screws. Twelve screws of each type were instrumented into either left or right pedicle with standard screw paired with unaugmented and dual outer diameter screw paired with augmented fenestrated screw in any given vertebra. Axial pullout testing was conducted at a rate of 5 mm/min. Force to failure (Newtons) for each pedicle screw was recorded. RESULTS: The augmented fenestrated screws had the highest pullout strength, which represented an average increase of 149%, 141%, and 78% in comparison to unaugmented, standard, and dual outer diameter screws, respectively. Pullout strength of unaugmented screws was comparable to that of standard screws, however it was significantly lower than dual outer diameter screws. CONCLUSIONS: Fenestrated screws augmented with PMMA improve the fixation strength and result in significantly higher pullout strength compared to dual outer diameter, standard and unaugmented fenestrated screws. Screws with dual outer diameter provided enhanced bone-screw purchase and may be considered as an alternative technique to increase the bone-screw interface in cases where augmentation using bone cement is not feasible. Unaugmented screws can be left in the pedicle even without cement and provide similar pullout strength to standard screws.

Quantitative dual-energy CT for phantomless evaluation of cancellous bone mineral density of the vertebral pedicle: correlation with pedicle screw pull-out strength.

OBJECTIVES: To evaluate quantitative dual-energy computed tomography (DECT) for phantomless analysis of cancellous bone mineral density (BMD) of vertebral pedicles and to assess the correlation with pedicle screw pull-out strength. METHODS: Twenty-nine thoracic and lumbar vertebrae from cadaver specimens were examined with DECT. Using dedicated post-processing software, a pedicle screw vector was mapped (R1, intrapedicular segment of the pedicle vector; R2, intermediate segment; R3, intracorporal segment; global, all segments) and BMD was calculated. To invasively evaluate pedicle stability, pedicle screws were drilled through both pedicles and left pedicle screw pull-out strength was measured. Resulting values were correlated using the paired t test and Pearson's linear correlation. RESULTS: Average pedicle screw vector BMD (R1, 0.232 g/cm(3); R2, 0.166 g/cm(3); R3, 0.173 g/cm(3); global, 0.236 g/cm(3)) showed significant differences between R1-R2 (P < 0.002) and R1-R3 (P < 0.034) segments while comparison of R2-R3 did not reach significance (P > 0.668). Average screw pull-out strength (639.2 N) showed a far stronger correlation with R1 (r = 0.80; P < 0.0001) than global BMD (r = 0.42; P = 0.025), R2 (r = 0.37; P = 0.048) and R3 (r = -0.33; P = 0.078) segments. CONCLUSIONS: Quantitative DECT allows for phantomless BMD assessment of the vertebral pedicle. BMD of the intrapedicular segment shows a significantly stronger correlation with pedicle screw pull-out strength than other segments. KEY POINTS: • Quantitative dual-energy CT enables evaluation of pedicle bone mineral density. • Intrapedicular segments show significant differences regarding bone mineral density. • Pedicle screw pull-out strength correlated strongest with R1 values. • Dual-energy CT may improve preoperative assessment before transpedicular screw fixation.

Association between facet joint osteoarthritis and the Oswestry Disability Index.

AIM: To investigate the correlation of facet joint osteoarthritis (FJOA) at lumbar levels L4/L5 and L5/S1 and the Oswestry Disability Index (ODI). METHODS: The study involved lumbar MRIs of 591 patients with a mean age of 47.3 years. The MRIs of the lumbar spine were performed on a 1.5 Tesla scanner (Magnetom(®) Avanto, Siemens AG, Erlangen, Germany) using a dedicated receive only spine coil. After initial blinding, each dataset was evaluated by 2 board certified radiologist with more than 5 years experience in musculoskeletal imaging. In total 2364 facet joints were graded. Degenerative changes of the facet joints were evaluated according to the 4-point scale as proposed by Weishaupt et al Functional status was assessed using the ODI. The index is scored from 0 to 100 and interpreted as follows: 0%-20%, minimal disability; 20%-40%, moderate disability; 40%-60%, severe disability; 60%-80%, crippled; 80%-100%, patients are bedbound. Spearman's coefficient of rank correlation was used for statistical analysis, with significance set at P < 0.05. RESULTS: In total 2364 facet joints at lumbar levels L4/5 and L5/S1 were analysed in 591 individuals. FJOA was present in 97% (L4/L5) and 98% (L5/S1). At level L4/5 (left/right) 17/15 (2.9%/2.5%) were described as grade 0, 146/147 (24.7%/24.9%) as grade 1, 290/302 (49.1%/51.1%) as grade 2 and 138/127 (23.4%/21.5%) as grade 3. At level L5/S1 (left/right) 10/11 (1.7%/1.9%) were described as grade 0, 136/136 (23.0%/23.0%) as grade 1, 318/325 (53.8%/55.0%) as grade 2 and 127/119 (21.5%/20.1%) as grade 3. Regarding the ODI scores, patients' disability had a minimum of 0% and a maximum of 91.11% with an arithmetic mean of 32.77% ± 17.02%. The majority of patients (48.39%) had moderate functional disability (21%-40%). There was no significant correlation between FJOA and ODI on both sides of lumbar level L4/5 and on the left side of lumbar level L5/S1. A weak positive correlation was evaluated between ODI and FJOA on the right side of lumbar level L5/S1. CONCLUSION: The missing correlation of FJOA and ODI confirms our clinical experience that imaging alone is an insufficient approach explaining low back pain. Clinical correlation is imperative for an adequate diagnostic advance in patients with low back pain.

Kümmell's Disease: Clarifying the Mechanisms and Patients' Inclusion Criteria.

The three major causes of vertebral body collapse include infection, malignant neoplasia, and trauma and it may be difficult to distinguish between them, particularly in the presence of severe osteoporosis. In 1891, however, Dr Hermann Kümmell, further added another possibility of vertebral body crush; the delayed posttraumatic collapse. As originally described, this rare clinical entity includes patients, who after a trivial trauma and an asymptomatic clinical course they develop a progressive vertebral body collapse and a painful kyphosis. Although more than a century has passed from its initial description, only few cases have been reported in the literature, whereas the main pathologic eliciting event is still under investigation. As a consequence, great controversy exists regarding the discrete features of the clinical course, its radiographic appearance and the histopathological findings. To explain the time lag between the initial trauma and the occurrence of the vertebral collapse, the hypothesis of ischemic necrosis was advanced. Equation of Kümmell's disease with vertebral osteonecrosis, however, has wrongly led many authors to report cases of Kümmell's disease, even in the absence of history of spinal trauma. On the other hand, high coincidence of vertebral osteonecrosis and the pathognomonic radiographic finding of intravertebral vacuum cleft, has further added to the confusion. In this review we present an overview of the literature on Kümmell's disease, focusing on the different proposed eliciting mechanisms. We also highlight controversial subjects on clinical course, diagnosis and treatment of this entity, in an attempt to further clarify patients' inclusion criteria.

Is tartrate-resistant acid phosphatase 5b a potent bio-marker for late stage aseptic implant loosening?

PURPOSE: Aseptic loosening is a serious complication after total joint arthroplasty. Plain radiography, along with clinical signs of prosthesis loosening, is the technique of first choice to evaluate loosening of joint replacements. Nevertheless, radiographical signs of osteolysis may not be apparent until progressed stages of loosening. Thus the search for alternative diagnostic methods is of great importance. The purpose of the present study was to evaluate the potential diagnostic significance of TRAP 5b, Osteocalcin, CrossLaps and Bone ALP for aseptic loosening of total joint replacements. METHODS: Thirty-seven patients (25 women, 12 men, mean age 65 years, age range 54-76 years) treated with revision surgery due to clinically and radiologically confirmed late aseptic prosthesis loosening were examined prospectively. Serum levels of TRAP 5b, Osteocalcin, CrossLaps and Bone ALP were compared with a matched control group (n = 39). RESULTS: We found a significant decrease in TRAP 5B level in patients with aseptic loosening. Bone ALP and Osteocalcin as markers of osteoblast activity, and CrossLaps as another resorption marker did not allow any prediction of bone remodeling in this late phase of loosening. CONCLUSION: In the "late" phase of aseptic joint replacement loosening, no increase of TRAP 5b and therefore no increase of osteoclast number and activity was measurable. Thus, in this situation an anti-osteolytic therapy with a bisphosphonate or denosumab would not gain any further benefit.

Dual-energy CT-based phantomless in vivo three-dimensional bone mineral density assessment of the lumbar spine.

PURPOSE: To evaluate the feasibility of phantomless in vivo dual-energy computed tomography (CT)-based three-dimensional (3D) bone mineral density (BMD) assessment in comparison with dual x-ray absorptiometry (DXA). MATERIALS AND METHODS: This retrospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. Data from clinically indicated dual-energy CT and DXA examinations within 2 months, comprising the lumbar spine of 40 patients, were included. By using automated dedicated postprocessing dual-energy CT software, the trabecular bone of lumbar vertebrae L1-L4 were analyzed and segmented. A mixed-effects model was used to assess the correlations between BMD values derived from dual-energy CT and DXA. RESULTS: One hundred sixty lumbar vertebrae were analyzed in 40 patients (mean age, 57.1 years; range, 24-85 years), 21 male (mean age, 54.3 years; range, 24-85 years) and 19 female (mean age, 58.5 years; range, 31-80 years). Mean BMD of L1-L4 determined with DXA was 0.995 g/cm(2), and 18 patients (45%) showed an osteoporotic BMD (T score less than -2.5) of at least two vertebrae. Mean dual-energy CT-based BMD of L1-L4 was 0.254 g/cm(3). Bland-Altman analysis with mixed effects demonstrated a lack of correlation between dual-energy CT-based and DXA-based BMD values, with a mean difference of 0.7441 and 95% limits of agreement of 0.7441 ± 0.4080. CONCLUSION: Dedicated postprocessing of dual-energy CT data allows for phantomless in vivo BMD assessment of the trabecular bone of lumbar vertebrae and enables freely rotatable color-coded 3D visualization of intravertebral BMD distribution.

Operations in spinal surgery are not always needed. Do we operate more than we should?

Lumbar disc herniation and low back pain are the main cause of sickness during labor life. The decision for operation is thought to be taken easily and as a result a lot of money is being spent for treatment and rehabilitation. The aim of this study was to evaluate whether conservative treatment is sufficient for treatment of lumbar disc herniation and low back pain and what percentage of the patients operated are satisfied with social and everyday life two years after operation. One hundred and twenty seven patients (67 male and 60 female) were treated because of lumbar disc herniation. No neurological deficiency or muscle weakness was observed. Seventy two patients underwent conservative treatment. Fifty five patients underwent microsurgical discectomy. Back and leg pain are reported on a visual analog scale (VAS) and with the Oswestry disability index (ODI). The Short Form-36 health survey (SF-36) and the European Quality of Life questionnaire (EQ-5D) should also be completed. Surgical data, including diagnosis, are recorded by the surgeon without access to the patient's questionnaires. Both groups (conservative and operative) improved from baseline with regard to SF-36 and ODI (all P<0.01). The results 2 years after surgery were similar for both groups, as measured with the SF-36 and the ODI. Both groups improved from baseline to follow-up with regard to both back pain and leg pain (all P<0.01). The frequency of returning to work was analyzed for those patients who were less than 65 years of age at the time of follow up, and who had been working before surgery. Statistical analysis indicates that there are no significant differences between the groups. The decision for operation is thought to be taken easily and as a result a lot of money is being spent for treatment and rehabilitation. In conclusion, this study shows that operative treatment is equal in outcome to conservative treatment and should follow, seen from an economic perspective, the conservative treatment.

Kümmell's disease: pathophysiology, diagnosis, treatment and the role of nuclear medicine. Rationale according to our experience.

Kümmell's disease (KD) is a rare clinical entity and includes patients, who after a trivial trauma and an asymptomatic period, develop a progressive vertebral body collapse and a painful kyphosis. The main pathologic eliciting event still remains unclear. Vertebral body collapse can be the result of infection, malignant neoplasia or trauma. It may be difficult to distinguish among them, particularly in osteoporosis. To explain the time lag between initial trauma and vertebral collapse, the hypothesis of ischemic necrosis was suggested. Many authors considering KD as a case of mere vertebral osteonecrosis have wrongly reported cases of osteonecrosis without a spinal trauma, as KD. The fact that intravertebral vacuum cleft often coexists with vertebral osteonecrosis further added to confusion. Various imaging modalities including bone scan support the diagnosis of KD. It is described that bone single photon emission tomography (SPET) or SPET/computed tomography scintigraphy using dynamic and static, acquisition can identify the chronicity of the lesions.

Anterior vertebroplasty of adjacent levels after vertebral body replacement.

The aim of this study was to evaluate the feasibility of a new method, which should help to avoid cage subsidence after vertebrectomy in short fusions. After implantation of an extendable vertebral body replacement (VBR) the two adjacent endplates to the fractured or destroyed vertebra were augmented with bone cement using the anterior approach in 20 patients with short circumferential fusion. All patients were followed up for 2 years clinically and radiographically. X-rays were reviewed for kyphosis, cage subsidence, presence of a solid fusion mass and instrumentation failure. Changes in every day activities (Oswestry Disability Index-ODI) and visual analogue scale (VAS), pain score, as well as technique-related complications were examined. The mean amount of kyphosis correction was 12.8° (±6.4°) and changed by only 0.3° (±0.4°) until last follow-up. Pain (VAS) and ODI scores were significantly improved and did not change until last follow-up. In all but two cases, the authors observed solid union with incorporation of the cage. No surgery-related complications were recorded. In one case revision was advised because of non-union due to septic loosening. The augmentation of the adjacent vertebras after anterior VBR provides an enhancement of the interface between cage and vertebra in cases with poor bone quality and in revision surgery. The technique is simple and safe, as the needles can be placed under visual control. Cement augmentation of the endplates may reduce interbody device subsidence.

Strontium ranelate enhances callus strength more than PTH 1-34 in an osteoporotic rat model of fracture healing.

Treatment of an underlying disease is often initiated after the occurrence of an osteoporotic fracture. Our aim was to investigate whether teriparatide (PTH 1-34) and strontium ranelate affect fracture healing in ovariectomized (OVX) rats when provided for the first time after the occurrence of an osteoporotic fracture. We combined the model of an OVX rat with a closed diaphyseal fracture. Sixty Sprague Dawley rats were randomly assigned to four groups. Fracture healing in OVX rats after treatment with pharmacological doses of strontium ranelate and PTH 1-34 was compared with OVX and sham-treated control groups. After 28 days, the femur was excised and scanned by micro computed tomography and the callus evaluated, after which biomechanical torsional testing was performed and torque and toughness until reaching the yield point were analyzed. Only treatment with strontium ranelate led to a significant increase in callus resistance compared to the OVX control rats, whereas both PTH 1-34 and strontium ranelate increased the bone volume/tissue volume ratio of the callus. The PTH 1-34-increased trabecular bone volume within the callus was even higher compared to sham. As for the callus tissue volume, the increase induced by strontium ranelate was significant, contrary to the changes induced by PTH. Callus in strontium ranelate-treated animals is more resistant to torsion compared with OVX control rats. To our knowledge, this is the first report of the enhancement of fracture healing by strontium ranelate. Because both treatments enhance bone and tissue volume within the callus, there may be a qualitative difference between the calluses of PTH 1-34- and strontium ranelate-treated OVX rats. The superior results obtained with strontium ranelate compared to PTH in terms of callus resistance could be the consequence of a better quality of the new bone formed within the callus.

Facilitating cartilage volume measurement using MRI.

PURPOSE: To compare quantitative cartilage volume measurement (CVM) using different slice thicknesses. MATERIALS AND METHODS: Ten knees were scanned with a 1.5T MRI (Sonata, Siemens, Erlangen, Germany) using a 3D gradient echo sequence (FLASH, fast low-angle shot). Cartilage volume of the medial and lateral tibial plateau was measured by two independent readers in 1.5mm, 3.0mm and 5.0mm slices using the Argus software application. Accuracy and time effectiveness served as control parameters. RESULTS: Determining cartilage volume, time for calculation diminished for the lateral tibial plateau from 384.6+/-127.7s and 379.1+/-117.6s to 214.9+/-109.9s and 213.9+/-102.2s to 122.1+/-60.1s and 126.8+/-56.2s and for the medial tibial plateau from 465.0+/-147.7s and 461.8+/-142.7s to 214.0+/-67.9s and 208.9+/-66.2s to 132.6+/-41.5s and 130.6+/-42.0s measuring 1.5mm, 3mm and 5mm slices, respectively. No statistically significant difference between cartilage volume measurements was observed (p>0.05) while very good inter-reader correlation was evaluated. CONCLUSION: CVM using 1.5mm slices provides no higher accuracy than cartilage volume measurement in 5mm slices while an overall time saving up to 70% is possible.