Temporary treatment with magnetically controlled growing rod for surgical correction of severe adolescent idiopathic thoracic scoliosis greater than 100°.

INTRODUCTION: Correction of severe idiopathic scoliosis poses surgical challenges. Treatment options entail anterior and/or posterior release, Halo-gravity traction (HGT) and three-column osteotomies (3CO). The authors report results with a novel technique of temporary short-term magnetically controlled growing rod (MCGR) as part of a posterior-only strategy to treat severe idiopathic major thoracic curves (MTC). METHODS: Seven patients with MTC > 100° treated with temporary MCGR were included. Mean age was 15 years. Preoperative MTC was av. 118° and TC-flexibility av. 19.8%. Patients underwent posterior instrumentation, periapical release using advanced Ponte osteotomies, segmental insertion of pedicle screws and a single MCGR. After av. 14 days, the second surgery was performed with removal of MCGR and final correction and fusion. The spinal height from lowest instrumented vertebra (LIV) to T1 was measured. MTC-correction and scoliosis correction index (SCI) were calculated. RESULTS: No patient suffered a major complication or neurologic deficit. Instrumentation was from T2 to L3 or L4. This kind of staged surgery achieved a correction of postop MTC to av. 39°, MTC-correction 67% and SCI of av. 4.3. Spinal height T1-LIV increased from preoperative av. 288 mm to postoperative av. 395 mm indicating an increase of > 10 cm. CONCLUSION: This is the first series of AIS patients that had temporary MCGR to treat severe thoracic scoliosis. A staged protocol including internal temporary distraction with MCGR after posterior release and definitive correction resulted in large MTC-correction and restoration of trunk height. Results indicate that technique has the potential to reduce the necessity for HGT and high-risk 3CO for the correction of severe scoliosis.

Flexibility of thoracic kyphosis affects postoperative sagittal alignment in adult patients with spinal deformity.

PURPOSE: Proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) surgery patients is a severe complication with potential need for revision surgery. While thoracic kyphosis (TK) is known to influence PJK, the role of TK flexibility is still unknown. We analyzed the influence of TK flexibility to predict postoperative sagittal alignment. METHODS: Patients with ASD, ≥ 2-year follow-up, and upper-most instrumented vertebra (UIV) including and below T10 were included in this retrospective study. TK flexibility, defined as > 10° difference of the TK in standing and supine imaging, was analyzed. Patient characteristics like age, sex, weight, total hip arthroplasty, and sagittal alignment parameters were studied. RESULTS: Sixty-five patients aged 66 ± 8 years were included in the study. Lowest instrumented vertebra was S1 or the ilium in 85% of them; the number of levels being fused averaged 7. Flexible TK was present in 31% (n = 20). These patients had a larger preoperative TK (p < 0.01), but no PJK was found (p = 0.04). In contrast, patients who underwent revision surgery had a decreased TK flexibility (p = 0.04) and increased PJK angle at follow-up (p = 0.01). In the non-flexible patients, the PJK was found in 14% of patients. CONCLUSIONS: Based on our retrospective data, TK flexibility influences the outcome of ASD surgery. In patients demonstrating no TK flexibility, a more cephalad UIV-level should be considered because spontaneous curve correction in the sagittal plane might be low in these patients. This new parameter should be included in future prediction models. These slides can be retrieved under Electronic Supplementary Material.

Posterior vertebral column resection with 360-degree osteosynthesis in osteoporotic kyphotic deformity and spinal cord compression.

Osteoporotic fractures with severe kyphosis and neurologic deficits often require decompression and stabilisation. To reduce the risk of procedure-related complications, single-stage posterolateral vertebrectomy and a 360-degree fusion can be performed. An adequate reduction of kyphotic deformity through this approach has not been reported. The aim of this study is to investigate the efficacy of kyphotic deformity reduction by this approach in osteoporotic situation. A retrospective analysis and chart review was performed for 10 consecutive patients who underwent posterolateral decompression and posterior vertebrectomy with dorsal mesh stabilisation and reduction of kyphotic deformity. Preoperative back pain was 8.6 on a visual analogue scale; it was reduced to 5.5 at discharge and 3.7 at the latest follow-up (18 months). The Frankel score improved from D to E (three patients) or was equal (E). Radiological segmental kyphosis was corrected from a mean of 25° to 5° (p < 0.008) postoperatively with a loss of 3° at follow-up (p < 0.005). Single-stage posterolateral vertebrectomy allow for a fast and safe reconstitution/preservation of neurological function in patients with osteoporotic fracture and kyphotic deformity. A significant correction of often-accompanied hyperkyphosis is possible without neurological deterioration and with an improved sagittal profile and good pain reduction.

Osteotomies in ankylosing spondylitis: where, how many, and how much?

INTRODUCTION: This article presents the current concepts of correction of spinal deformity in ankylosing spondylitis (AS) patients. Untreated AS can be a debilitating disease. In a few patients, disease progression results in severe spinal deformity affecting not only the thoracolumbar, but also the cervical spine. Surgery for correction in AS patients has a long history. With the advent of modern instrumentation, standardization of surgical and anesthesiologic techniques, surgical safety and corrective results could be improved and experiences from lumbar osteotomies could be transferred to the cervical spine. METHODS: This article presents the current concepts of correction of spinal deformity in AS patients. In particular, questions regarding the localization and number of osteotomies, the optimal surgical target angle as well as planning and prediction of postoperative alignment are discussed. RESULTS: Insight into recent technical developments, current challenges with correction and geometric analysis of center of rotation (COR) in cervical 3-column osteotomies (3CO) will be presented. CONCLUSION: The article should encourage readers to improve surgical correction efficacy and provide a better understanding of correction geometry in 3CO for thoracolumbar and cervical spinal deformities.

In situ analysis of interleukin-23- and interleukin-12-positive cells in the spine of patients with ankylosing spondylitis.

OBJECTIVE: The interleukin-12 (IL-12) family of cytokines has been suggested to play a critical role in inflammatory autoimmune diseases, and recent studies analyzing peripheral blood and synovial fluid from patients with spondyloarthritides suggest that IL-23 might be a proinflammatory factor in these disorders. This study was undertaken to investigate the presence and source of IL-23 in the spines of patients with ankylosing spondylitis (AS). METHODS: The frequency of IL-23-positive and IL-12-positive cells within the subchondral bone marrow and within fibrous tissue replacing normal bone marrow in facet joints of patients with AS was analyzed by immunohistochemistry. The origin of IL-23-positive cells was determined by double staining of CD163+ macrophages, CD68+ macrophages, CD1a+ dendritic cells, tryptase-positive mast cells, myeloperoxidase-positive cells, CD20+ B cells, and CD3+ T cells. Findings in 28 facet joints from 22 AS patients were compared with those in 20 facet joints from 13 patients with osteoarthritis (OA) and 10 normal control specimens. RESULTS: The frequency of IL-23-positive cells in subchondral bone marrow from the joints of AS patients (mean ± SD 42.50 ± 32.81/high-power field [hpf]) was significantly increased compared to that in subchondral bone marrow from OA patients (OA 15.63 ± 29.90/hpf) (P = 0.0017) or controls (19.36 ± 16.8/hpf) (P = 0.03). Myeloperoxidase-positive cells and, to a lesser extent, macrophages and dendritic cells were found to be the origin of IL-23 in the bone marrow. In AS and OA patients, the frequency of IL-23-positive cells was significantly higher than that of IL-12-positive cells (P < 0.001 in both patient groups). Within fibrous tissue from AS and OA facet joints, IL-23 was predominantly produced by CD163+ macrophages (mean ± SD 0.64 ± 0.59/hpf and 4.36 ± 3.4/hpf, respectively) and CD68+ macrophages (2.3 ± 0.65/hpf and 6.54 ± 4.1/hpf, respectively). CONCLUSION: IL-23 is expressed in the subchondral bone marrow and in fibrous tissue replacing bone marrow in facet joints of patients with AS. It might have a role in inflammatory processes and in chronic changes in AS joints, which makes it an interesting potential therapeutic target in this disease.

Clinical and surgical results related to anterior-only multilevel cervical decompression and instrumented fusion for degenerative disease.

Introduction: Anterior-only multilevel cervical decompression and fusion surgery (AMCS) on 3-5-levels is challenging due to potential complications. Also, outcome predictors after AMCS are poorly understood. Research Question: We hypothesize that in patients with at most mild/moderate cervical kyphosis (CK) of the cervical spine, restoration of cervical lordosis (CL) positively influences clinical outcomes. Methods: Analysis of consecutive patients presenting with symptomatic degenerative cervical disease or non-union undergoing AMCS. We measured CL from C2 to C7, Cobb angle of fused levels (fusion angle, FA), C7-Slope, and sagittal vertical axis C2-7 (cSVA, stratified into ≤4cm∖>4cm). Patients with excellent outcome were grouped in BEST-outcomes and with moderate/poor outcomes in WORST-outcomes. Results: We included 244 patients. Fifty-four percent had 3-, 39% 4-level and 7% had 5-level fusion. At mean follow-up of 26 months, 41% of patients achieved BEST-outcome and 23% WORST-outcome. Complications and reoperation rates did not significantly differ. Non-union significantly influenced outcomes. The number of patients with non-union was significantly higher in patients with a preoperative cSVA>4cm (OR 13.1 (95%CI:1.8-96.8). Our model, based on the multivariable analysis with WORST-outcome as outcome variable showed a high accuracy (NPV=73%, PPV=77%, specificity=79%, sensitivity=71%). Discussion and Conclusion: In 3-5-level AMCS, improvement of FA and cSVA were independent predictors of clinical outcome. Improvement of CL positively influenced clinical outcomes and rates of non-union.

Surgical Realignment After Anterior Multilevel Decompression Using Cages and Plate for 3-level to 5-level Degenerative Fusions: Lessons Learned From the Analysis of Geometric Changes, Reciprocal Coupling, and Prediction of Sagittal Cervical Balance.

STUDY DESIGN: Retrospective, single-center case study. OBJECTIVE: Postoperative cervical imbalance with cervical sagittal vertical axis (cSVA) >4 cm can be predicted in 3-level to 5-level anterior-only cervical multilevel fusion surgery (ACMS). SUMMARY OF BACKGROUND DATA: Previous studies established correlations between cervical kyphosis (CK) correction and postoperative balance (cSVA ≤4 cm) with improved clinical outcomes. Understanding of what influences restoration of cervical lordosis (CL) in patients with degenerative disease with mild to moderate CK subjected to ACMS is important. To achieve a better understanding of geometric changes after ACMS, this study examines factors predicting perioperative alignment changes and regional interdependencies. MATERIALS AND METHODS: Analysis of patients with ACMS. Analysis included patient baseline characteristics, demographics and complications, and focused on radiographic measures including CL C2-7, fusion angle (FA), C7-Slope (C7S), T1-slope (T1S), T1-CL mismatch, and cSVA (cSVA ≤4 cm/>4 cm). We aimed to predict postoperative imbalance (cSVA >4 cm) and conducted a multivariable logistic regression analysis. RESULTS: Inclusion of 126 patients with 3-level to 5-level ACMS, mean age was 56 years and 4 fusion levels on average. Preoperative CK was present in 9%, mean FA-correction was 8 degrees, maximum 46 degrees. Postoperatively, 14 patients had cSVA >4 cm. A neural network model for prediction of cSVA >4 cm was established including preoperative cSVA, preoperative CL and correction of FA. The model achieved high performance (positive predictive value=100%, negative predictive value=94%, specificity=100%, sensitivity=20%). Also, variables such as nonunion, chronic lumbar pain or thoracolumbar multilevel fusion influenced the postoperative cSVA >4 cm rate. Alignment analysis highlighted strong correlations between C7S/T1S and cSVA/C2-tilt ( r =0.06/ r =0.7, P <0.0001). A formula was established to transfer cSVA data into C2-tilt data. CONCLUSION: This study identified independent variables predicting postoperative cSVA >4 cm including FA, which can be influenced by the surgeon. Our model supports the decision-making process targeting a postoperative cSVA ≤4 cm.

Center of rotation analysis for thoracic and lumbar 3-column osteotomies in patients with sagittal plane spinal deformity: insights in geometrical changes can improve understanding of correction mechanics.

OBJECTIVE: Three-column osteotomy (3CO) is used for severe spinal deformities. Associated complications include sagittal translation (ST), which can lead to neurological symptoms. Mismatch between the surgical center of rotation (COR) and the concept of the ideal COR is a potential cause of ST. Matching surgical with conceptual COR is difficult with pedicle subtraction osteotomy (PSO) and vertebral column resection (VCR). This mismatch influences correction geometry, which can prevent maximum possible correction. The authors' objective was to examine the sagittal correction geometry and surgical COR of thoracic and lumbar 3CO. METHODS: In a retrospective study of patients with PSO or VCR for severe sagittal plane deformity, analysis of surgical COR was performed using pre- and postoperative CT scans in the PSO group and digital radiographs in the VCR group. Radiographic analysis included standard deformity measurements and regional kyphosis angle (RKA). All patients had 2-year follow-up, including neurological outcome. Preoperative CT scans were studied for rigid osteotomy sites versus mobile osteotomy sites. Additional radiographic analysis of surgical COR was based on established techniques superimposing pre- and postoperative images. Position of the COR was defined in a rectangular net layered onto the osteotomy vertebrae (OVs). RESULTS: The study included 34 patients undergoing PSO and 35 undergoing VCR, with mean ages of 57 and 29 years and mean RKA corrections of 31° and 49°, respectively. In the PSO group, COR was mainly in the anterior column, and surgical and conceptual COR matched in 22 patients (65%). Smaller RKA correction (27° vs 32°, p = 0.09) was seen in patients with anterior eccentric COR. Patients with rigid osteotomy sites were more likely to have an anterior eccentric COR (41% vs 11%, p = 0.05). In the VCR group, 20 patients (57%) had single-level VCR and 15 (43%) had multilevel VCR. COR was mainly located in the anterior or middle column. Mismatch between surgical and conceptual COR occurred in 24 (69%) patients. Larger RKA correction (63° vs 45°, p = 0.03) was seen in patients with anterior column COR. Patients with any posterior COR had a smaller RKA correction compared to the rest of the patients (42° vs 61°, p = 0.007). CONCLUSIONS: Matching the surgical with the conceptual COR is difficult and in this study failed in one- to two-thirds of all patients. In order to avoid ST during correction of severe deformities, temporary rods, tracking rods, or special instruments should be used for correction maneuvers.

Surgical outcomes with anatomic reduction of high-grade spondylolisthesis revisited: an analysis of 101 patients.

OBJECTIVE: The ideal strategy for high-grade L5-S1 isthmic spondylolisthesis (HGS) remains controversial. Critical questions include the impact of reduction on clinical outcomes, rate of pseudarthrosis, and postoperative foot drop. The scope of this study was to delineate predictors of radiographic and clinical outcome factors after surgery for HGS and to identify risk factors of foot drop. METHODS: This was a single-center analysis of patients who were admitted for HGS, defined as grade III or greater L5 translation according to the Meyerding (MD) classification. Complete postoperative reduction was defined as MD grade I or less and L5 slip < 20%. Forty-six patients completed health-related quality-of-life questionnaires (Oswestry Disability Index, Physical Component Summary of SF-36, and visual analog scale) and ≥ 2 years' follow-up (average 105 months). A 540° approach was used in 61 patients, a 360° approach was used in 40, and L5 corpectomy was used in 17. Radiographic analysis included measures of global spinopelvic balance (e.g., pelvic incidence [PI], lumbar lordosis) and measurement of lumbosacral kyphosis angle (LSA), L4 slope (L4S), L5 slip (%), and postoperative increase of L5-S1 height. RESULTS: The authors included 101 patients with > 1 year of clinical and radiographic follow-up. The mean age was 26 years. Average preoperative MD grade was 3.8 and average L5 slip was 81%; complete reduction was achieved in 55 and 42 patients, respectively, according to these criteria. At follow-up, LSA correlated with all clinical outcomes (r ≥ 0.4, p < 0.05). Forty patients experienced a major complication. Risk was increased in patients with greater preoperative deformity (i.e., LSA) (p = 0.04) and those who underwent L5 corpectomy (p < 0.01) and correlated with greater deformity correction. Thirty-one patients needed revision surgery, including 17 for pseudarthrosis. Patients who needed revision surgery had greater preoperative deformity (i.e., MD grade and L5 slip) (p < 0.01), greater PI (p = 0.02), and greater postoperative L4S (p < 0.01) and were older (p = 0.02), and these patients more often underwent L5 corpectomy (p < 0.01). Complete reduction was associated with lower likelihood of pseudarthrosis (p = 0.08) and resulted in better lumbar lordosis correction (p = 0.03). Thirty patients had foot drop, and these patients had greater MD grade and L5 slip (p < 0.01) and greater preoperative LSA (p < 0.01). These patients with foot drop more often required L5 corpectomy (p < 0.01). Change in preoperative L4S (p = 0.02), LSA (p < 0.01), and L5-S1 height (p = 0.02) were significantly different between patients with foot drop and those without foot drop. A significant risk model was established that included L4S change and PI as independent variables and foot drop as a dependent variable (82% negative predictive value and 71% positive predictive value, p < 0.01). CONCLUSIONS: Multivariable analysis identified factors associated with foot drop, major complications, and need for revision surgery, including degree of deformity (MD grade and L5 slip) and correction of LSA. Functional outcome correlated with LSA correction.

Resolution of the lumbosacral fractional curve and evaluation of the risk for adding on in 101 patients with posterior correction of Lenke 3, 4, and 6 curves.

OBJECTIVE: In double and triple major adolescent idiopathic scoliosis curves it is still controversial whether the lowest instrumented vertebra (LIV) should be L3 or L4. Too short a fusion can impede postoperative distal curve compensation and promote adding on (AON). Longer fusions lower the chance of compensation by alignment changes of the lumbosacral curve (LSC). This study sought to improve prediction accuracy for AON and surgical outcomes in Lenke type 3, 4, and 6 curves. METHODS: This was a retrospective multicenter analysis of patients with adolescent idiopathic scoliosis who had Lenke 3, 4, and 6 curves and ≥ 1 year of follow-up after posterior correction. Resolution of the LSC was studied by changes of LIV tilt, L3 tilt, and L4 tilt, with the variables resembling surrogate measures for the LSC. AON was defined as a disc angle below LIV > 5° at follow-up. A matched-pairs analysis was done of differences between LIV at L3 and at L4. A multivariate prediction analysis evaluated the AON risk in patients with LIV at L3. Clinical outcomes were assessed by the Scoliosis Research Society 22-item questionnaire (SRS-22). RESULTS: The sample comprised 101 patients (average age 16 years). The LIV was L3 in 54%, and it was L4 in 39%. At follow-up, 87% of patients showed shoulder balance, 86% had trunk balance, and 64% had a lumbar curve (LC) ≤ 20°. With an LC ≤ 20° (p = 0.01), SRS-22 scores were better and AON was less common (26% vs 59%, p = 0.001). Distal extension of the fusion (e.g., LIV at L4) did not have a significant influence on achieving an LSC < 20°; however, higher screw density allowed better LC correction and resulted in better spontaneous LSC correction. AON occurred in 34% of patients, or 40% if the LIV was L3. Patients with AON had a larger residual LSC, worse LC correction, and worse thoracic curve (TC) correction. A total of 44 patients could be included in the matched-pairs analysis. LC correction and TC correction were comparable, but AON was 50% for LIV at L3 and 18% for LIV at L4. Patients without AON had a significantly better LC correction and TC correction (p < 0.01). For patients with LIV at L3, a significant prediction model for AON was established including variables addressed by surgeons: postoperative LC and TC (negative predictive value 78%, positive predictive value 79%, sensitivity 79%, specificity 81%). CONCLUSIONS: An analysis of 101 patients with Lenke 3, 4, and 6 curves showed that TC and LC correction had significant influence on LSC resolution and the risk for AON. Improving LC correction and achieving an LC < 20° offers the potential to lower the risk for AON, particularly in patients with LIV at L3.

Diagnostic accuracy of CT scan-based criteria compared with surgical exploration for the analysis of cervical fusion and nonunion.

OBJECTIVE: Computed tomography (CT) scans are accepted as the imaging standard of reference to define union after anterior cervical discectomy and fusion (ACDF). However, ideal CT criteria to diagnose union have not been identified or validated. The objective of this study was to analyze the diagnostic value of 9 CT-based criteria and identify the ideal criteria among them to assess cervical fusion after ACDF using surgical exploration as the standard of reference. METHODS: The authors performed a retrospective radiographic study of a single surgeon's prospective assessment of osseous fusion during cervical revision surgery by analyzing complete radiographic data in 44 patients who underwent anterior cervical revision surgery due to symptomatic suspected nonunion or adjacent level disease. All patients received standard preoperative CT scans, which were assessed by an independent radiologist to evaluate 9 diagnostic criteria for osseous union. During revision surgery, scar tissue was removed and manual segmental translation tests were performed. Nonunion was defined by visualized motion at the treated ACDF level. RESULTS: In total, 44 patients were included in the study (30 men; patient age 54 ± 6 years, BMI 28 ± 5 kg/m2). For analysis of fusion, 75 cervical levels were explored, of which 61 levels (81%) showed intraoperative movement indicating nonunion. Statistical analysis showed that of the 9 parameters used to diagnose bone union, "bridging bone on ≥ 3 CT slices" yielded the highest sensitivity (100%) and specificity (58%). Multivariate analysis revealed that prediction accuracy was not increased if several criteria were combined to determine fusion. CONCLUSIONS: The authors found that the best indicator of bone union was the item bridging bone on ≥ 3 CT slices. Combining the scoring of more than one criterion did not increase the diagnostic accuracy.

Mid- to long-term outcome of instrumented anterior cervical fusion for subaxial injuries.

The management of patients with subaxial cervical injuries lacks consensus, particularly in regard to the decision which surgical approach or combination of approaches to use and which approach yields the best clinical outcome in the distinct injury. The trauma literature is replete with reports of surgical techniques, complications and gross outcome assessment in heterogeneous samples. However, data on functional and clinical outcome using validated outcome measures are scanty. Therefore, the authors performed a study on plated anterior cervical decompression and fusion for unstable subaxial injuries with focus on clinical outcome. For the purpose of a strongly homogenous subgroup of patients with subaxial injuries without spinal cord injuries, robust criteria were applied that were fulfilled by 28 patients out of an original series of 131 subaxial injuries. Twenty-six patients subjected to 1- and 2-level fusions without having spinal cord injury could be surveyed after a mean of 5.5 years (range 16-128 months). The cervical spine injury severity score averaged 9.6. Cross-sectional outcome assessment included validated outcome measures (Neck pain disability index, Cervical Spine Outcome Questionnaire, SF-36), the investigation of construct failure and successful surgical outcome were defined by strict criteria, the reconstruction and maintenance of local and total cervical lordosis, adjacent-segment degeneration and intervertebral motion, and the fusion-rate using an interobserver assessment. Self-rated clinical outcome was excellent or good in 81% of patients and moderate or poor in 19% that corresponded to the results of the validated outcome measures. Results of the NPDI averaged 12.4 +/- 12.7% (0-40). With the SF-36 mean physical and mental component summary scores were 47.0 +/- 9.8 (18.2-59.3) and 52.2 +/- 12.4 (14.6-75.3), respectively. Using merely non-constrained plates, construct failure was observed in 31% of cases and loss of local lordosis, expressed as a mean injury angle of 14 degrees, postoperative angle of -5.5 degrees and follow-up angle of -1 degree, was significant. However, total cervical lordosis was within the limits of normalcy (-24.3 degrees +/- 13.3) and fusion-rate was 88.5%. The progression of adjacent-level degeneration was shown to be significantly influenced by a decreased plate-to-disc-distance. Adjacent-level intervertebral motion was not altered due to the adjacent fusion, but reduced in the presence of advanced adjacent-level degeneration. Patients were more likely to maintain a high satisfaction level if they succeeded to maintain segmental lordosis (<0 degree), had a solid fusion, an increased plate-to-disc distance, and if they were judged to have a successful surgical outcome that included the absence of construct failure and reconstruction of lordosis within +/-1 SD of normalcy. Using validated outcome vehicles the interdependencies between radiographical, functional and clinical outcome parameters could be substantiated with statistically significant correlations. The use of validated outcome vehicles in a subgroup of patients with plated anterior cervical fusions for subaxial injuries is recommended. With future studies, it enables objective comparison of surgical techniques and related radiographical, functional and clinical outcome.

Cervical anterior transpedicular screw fixation. Part I: Study on morphological feasibility, indications, and technical prerequisites.

Multilevel cervical spine procedures can challenge the stability of current anterior cervical screw-and-plate systems, particularly in cases of severe three-column subaxial cervical spine injuries and multilevel plated reconstructions in osteoporotic bone. Supplemental posterior instrumentation is therefore recommended to increase primary construct rigidity and diminish early failure rates. The increasing number of successfully performed posterior cervical pedicle screw fixations have enabled more stable fixations, however most cervical pathologies are located anteriorly and preferably addressed by an anterior approach. To combine the advantages of the anterior approach with the superior biomechanical characteristics of cervical pedicle screw fixation, the authors developed a new concept of a cervical anterior transpedicular screw-and-plate system. An in vivo anatomical study was performed to explore the feasibility of anterior transpedicular screw fixation (ATPS) in the cervical spine. The morphological study was conducted based on 29 cervical spine CT scans from healthy patients and measurements were performed on the pedicle sizes, angulations, vertebral body depth, height and width at C2 to T1. Significant morphologic parameters for the new technique are discussed. These parameters include the sagittal and transverse intersection points of the pedicle axis with the anterior vertebral body wall, as well as the distances between sagittal intersection points from C2 to T1. On the basis of these results, standard spine models were reconstructed and used for the conceptual development of a preclinical release prototype of an anterior transpedicular screw-and-plate system. The morphological feasibility of the new technique is demonstrated, and its indications, biomechanical considerations, as well as surgical prerequisites are thoroughly discussed. In the future, the technique of cervical anterior transpedicular screw fixation might diminish the number of failures in the reconstruction of multilevel and three-column cervical spine instabilities, and avoid the need for supplemental posterior instrumentation.

Long-term investigation of nonsurgical treatment for thoracolumbar and lumbar burst fractures: an outcome analysis in sight of spinopelvic balance.

The nonsurgical treatment of thoracolumbar (TLB) and lumbar burst (LB) fractures remains to be of interest, though it is not costly and avoids surgical risks. However, a subset of distinct burst fracture patterns tend to go with a suboptimal radiographic and clinical long-term outcome. Detailed fracture pattern and treatment-related results in terms of validated outcome measures are still lacking. In addition, there are controversial data on the impact of local posttraumatic kyphosis that is associated, in particular, with nonsurgical treatment. The assessment of global spinal balance following burst fractures has not been assesed, yet. Therefore, the current study intended to investigate the radiographical and clinical long-term outcome in neurologically intact patients with special focus on the impact of regional posttraumatic kyphosis, adjacent-level compensatoric mechanisms, and global spine balance on the clinical outcome. For the purpose of a homogenous sample, strong in- and exclusion criteria were applied that resulted in a final study sample of 21 patients with a mean follow-up of 9.5 years. Overall, clinical outcome evaluated by validated measures was diminished, with 62% showing a good or excellent outcome and 38% a moderate or poor outcome in terms of the Greenough Low Back Outcome Scale. Notably, vertebral comminution in terms of the load-sharing classification, posttraumatic kyphosis, and an overall decreased lumbopelvic lordosis showed a significant effect on clinical outcome. A global and segmental curve analysis of the spine T9 to S1 revealed significant alterations as compared to normals. But, the interdependence of spinopelvic parameters was not disrupted. The patients' spinal adaptability to compensate for the posttraumatic kyphotic deformity varied in the ranges dictated by pelvic geometry, in particular the pelvic incidence. The study substantiates the concept that surgical reconstruction and maintenance of a physiologically shaped spinal curve might be the appropriate treatment in the more severely crushed TLB and LB fractures.

Patellar blood flow during knee arthroplasty surgical exposure: Intraoperative monitoring by laser doppler flowmetry.

Patellofemoral complications following knee arthroplasty are a well-known problem. Patellar ischemia has been suspected to be causative for fracture, anterior knee pain, and patella component failure. The purpose of this study was to assess the influence of knee arthroplasty surgical dissection on patellar blood flow. Patellar blood flow was measured by means of intraosseous laser Doppler flowmetry (LDF) in 10 patients undergoing total knee arthroplasty by a standard medial parapatellar approach. The initial blood flow was 121.6 +/- 114.7 AU. The signal significantly decreased by 71% (p = 0.0051) when the knee was flexed and lost the pulsatile signal pattern in 80%. After arthrotomy, the signal was 100.1 +/- 120.3 AU in extension. The lowest signal was found in flexion and eversion of the patella (mean, 18 +/- 10.7 AU) and all signals lost pulsatility. As compared to the initial values, completion of the soft tissue dissection did not lead to a significant change of the blood flow signal (121.3 +/- 104.8; p = 0.6835). Flexion of the knee joint markedly reduced patellar perfusion. Standard medial parapatellar approach did not significantly change patellar blood flow. This study does not support the theory of postoperative patellar ischemia as a cause of anterior knee pain or patellofemoral problems.

Treatment of chronic radial epicondylitis with botulinum toxin A. A double-blind, placebo-controlled, randomized multicenter study.

BACKGROUND: Radial epicondylitis (tennis elbow) is the most frequent type of myotendinosis. Patients can experience substantial loss of function, especially when this condition becomes chronic. A successful therapy has not yet been established. A preliminary study of injections of botulinum toxin A in patients with chronic epicondylitis has shown promising results. METHODS: In the present prospective, controlled, double-blinded clinical trial, 130 patients were examined at sixteen study centers. A single injection of botulinum toxin A into the painful origin of the forearm extensor muscles was performed. Follow-up examinations were performed at two, six, twelve, and eighteen weeks. Clinical findings were documented with use of a new clinical pain score and with a visual analogue scale. A global assessment of the result of treatment was also provided by the patient and the attending doctor. Strength of extension of the third finger and the wrist was evaluated with use of the Brunner method, and grip strength (fist closure strength) was measured with a vigorimeter. RESULTS: The group treated with botulinum toxin A was found to have a significant improvement in the clinical findings, compared with those in the placebo group, as early as the second week after injection (p = 0.003). Subjective general assessment also showed improvement in that group, compared with the placebo group, at six weeks (p = 0.001) and at the time of the final examination (at eighteen weeks) (p = 0.001). There was a consistent increase in fist closure strength in both the group treated with botulinum toxin A and the control group, but there was no significant difference between groups. As was expected as a side effect, extension of the third finger was observed to be significantly weakened at two weeks but this complication had completely resolved at eighteen weeks. CONCLUSIONS: We concluded that local injection of botulinum toxin A is a beneficial treatment for radial epicondylitis (tennis elbow). The treatment can be performed in an outpatient setting and does not impair the patient's ability to work.

Sensitivity of osteoblasts, fibroblasts, bone marrow cells, and dendritic cells to 5-aminolevulinic acid based photodynamic therapy.

INTRODUCTION: Photodynamic therapy with 5-aminolevulinic acid (5-ALA-PDT) exerts cell type specific effects on target cells. Since chondrocytes were found to be more resistant than osteoblasts to 5-ALA-PDT, the pre-treatment of osteochondral grafts with 5-ALA-PDT may represent a means to devitalize the osseous portion while maintaining functional cartilage. The present study was designed to determine the effects of 5-ALA-PDT in vitro on cell populations residing in skeletal tissues. METHODS: Osteoblasts, fibroblasts, bone marrow cells, and dendritic cells were incubated with 0.5 mM 5-ALA for 4 h. Protoporphyrin IX (PpIX) accumulation and after exposure to light cellular functions were assessed for up to 6 days. RESULTS: Accumulation of PpIX reached a plateau at 0.5 mM in osteoblasts, fibroblasts, and dendritic cells, and at 2.0 mM in bone marrow cells. At 0.5 mM 5-ALA, similar responses to illumination were observed in all cells with a survival rate of less than 12% at a light dose of 20 J/cm(2). The function of osteoblasts (proliferation, levels of mRNA encoding collagen type I, alkaline phosphatase activity) and fibroblasts (proliferation, levels of mRNAs encoding collagens type I and III) was not affected, when the cells were treated with 5-ALA and light doses of < or =10 J/cm(2). Paralleling the reduction of viable cells after 5-ALA-PDT, the capacity of dendritic cells to stimulate T cells in a mixed leukocyte reaction decreased to 4+/-2% at 20 J/cm(2). CONCLUSION: The investigated cell types were sensitive to 5-ALA-PDT and the residual cell debris did not elicit an allogenic response. These findings, together with the resistance of chondrocytes to 5-ALA-PDT, encourage the further investigation of this protocol in the pretreatment of osteochondral allografts.

4- and 5-level anterior fusions of the cervical spine: review of literature and clinical results.

In the future, there will be an increased number of cervical revision surgeries, including 4- and more-levels. But, there is a paucity of literature concerning the geometrical and clinical outcome in these challenging reconstructions. To contribute to current knowledge, we want to share our experience with 4- and 5-level anterior cervical fusions in 26 cases in sight of a critical review of literature. At index procedure, almost 50% of our patients had previous cervical surgeries performed. Besides failed prior surgeries, indications included degenerative multilevel instability and spondylotic myelopathy with cervical kyphosis. An average of 4.1 levels was instrumented and fused using constrained (26.9%) and non-constrained (73.1%) screw-plate systems. At all, four patients had 3-level corpectomies, and three had additional posterior stabilization and fusion. Mean age of patients at index procedure was 54 years with a mean follow-up intervall of 30.9 months. Preoperative lordosis C2-7 was 6.5 degrees in average, which measured a mean of 15.6 degrees at last follow-up. Postoperative lordosis at fusion block was 14.4 degrees in average, and 13.6 degrees at last follow-up. In 34.6% of patients some kind of postoperative change in construct geometry was observed, but without any catastrophic construct failure. There were two delayed unions, but finally union rate was 100% without any need for the Halo device. Eleven patients (42.3%) showed an excellent outcome, twelve good (46.2%), one fair (3.8%), and two poor (7.7%). The study demonstrated that anterior-only instrumentations following segmental decompressions or use of the hybrid technique with discontinuous corpectomies can avoid the need for posterior supplemental surgery in 4- and 5-level surgeries. However, also the review of literature shows that decreased construct rigidity following more than 2-level corpectomies can demand 360 degrees instrumentation and fusion. Concerning construct rigidity and radiolographic course, constrained plates did better than non-constrained ones. The discussion of our results are accompanied by a detailed review of literature, shedding light on the biomechanical challenges in multilevel cervical procedures and suggests conclusions.

Granulation Tissue Eroding the Subchondral Bone Also Promotes New Bone Formation in Ankylosing Spondylitis.

OBJECTIVE: We previously suggested that fibroblast-rich granulation tissue eroding the subchondral bone is instrumental in the joint remodeling that occurs in ankylosing spondylitis (AS). The purpose of this study was to determine if this granulation tissue also carries bone-forming capabilities, which we approached by searching for bone-forming cells (hypertrophic chondrocytes, osteoblasts) in its vicinity. We also assessed adipogenic tissue transformation, which has been suggested to be an intermediate feature in AS bone formation based on imaging studies. METHODS: The facet joints of AS patients, osteoarthritis (OA) patients, and autopsy subjects (controls) were screened for subchondral granulation tissue. We searched for hypertrophic chondrocytes by assessing RUNX-2, type X collagen, and matrix metalloproteinase 13 (MMP-13) expression, for osteoblasts by analyzing RUNX-2, CD56, and type I collagen expression, as well as for signs of new bone formation. Adipocytes and lipid accumulation were assessed in Safranin O-stained sections. RESULTS: In the joints of AS and OA patients, RUNX-2-positive cells were found to be lining the granulation tissue. These cells coexpressed type I collagen but lacked type X collagen and MMP-13 expression, confirming their osteoblastic nature. In 91% of AS joints and in 20% of OA joints (P < 0.05), we observed foci of new bone formation at contact zones between the granulation tissue and the cartilage. Joints containing bony spots showed greater replacement of the adjacent bone marrow by granulation tissue than did joints without bone formation (P < 0.05). The granulation tissue often contained adipocytes and lipid accumulations. Replacement of the subchondral bone marrow by fat tissue was also frequently found but was not associated with new bone formation. CONCLUSION: The subchondral granulation tissue carries osteoblasts, which promote new bone formation, leading to intraarticular ankylosis of the facet joints in AS.

Cartilage in facet joints of patients with ankylosing spondylitis (AS) shows signs of cartilage degeneration rather than chondrocyte hypertrophy: implications for joint remodeling in AS.

INTRODUCTION: In ankylosing spondylitis (AS), joint remodeling leading to joint ankylosis involves cartilage fusion. Here, we analyzed whether chondrocyte hypertrophy is involved in cartilage fusion and subsequent joint remodeling in AS. METHODS: We assessed the expression of chondrocyte hypertrophy markers runt-related transcription factor 2 (Runx2), type X collagen (COL10), matrix metalloproteinase 13 (MMP13), osteocalcin and beta-catenin and the expression of positive bone morphogenic proteins (BMPs) and negative regulators (dickkopf-1 (DKK-1)), sclerostin, (wingless inhibitory factor 1 (wif-1)) of chondrocyte hypertrophy in the cartilage of facet joints from patients with AS or osteoarthritis (OA) and from autopsy controls (CO) by immunohistochemistry. Sex determining region Y (SRY)-box 9 (Sox9) and type II collagen (COL2) expression was assessed as indicators of chondrocyte integrity and function. RESULTS: The percentage of hypertrophic chondrocytes expressing Runx2, COL10, MMP13, osteocalcin or beta-catenin was significantly increased in OA but not in AS joints compared to CO joints. Frequencies of sclerostin-positive and DKK-1-positive chondrocytes were similar in AS and CO. In contrast, wif-1- but also BMP-2- and BMP-7-expressing and Sox9-expressing chondrocytes were drastically reduced in AS joints compared to CO as well as OA joints whereas the percentage of COL2-expressing chondrocytes was significantly higher in AS joints compared to CO joints. CONCLUSIONS: We found no evidence for chondrocyte hypertrophy within hyaline cartilage of AS joints even in the presence of reduced expression of the wnt inhibitor wif-1 suggesting that chondrocyte hypertrophy is not a predominant pathway involved in joint fusion and remodeling in AS. In contrast, the reduced expression of Sox9, BMP-2 and BMP-7 concomitantly with induced COL2 expression rather point to disturbed cartilage homeostasis promoting cartilage degeneration in AS.