Decreasing implant load indicates spinal fusion when measured continuously.

Reliable and timely assessment of bone union between vertebrae is considered a key challenge after spinal fusion surgery. Recently, a novel sensor concept demonstrated the ability to objectively assess posterolateral fusion based on continuous implant load monitoring. The aim of this study was to investigate systematically the concept in a mono-segmental fusion model using an updated sensor setup. Three sheep underwent bilateral facetectomy at level L2-L3 and L4-L5. The segments were stabilized using two unconnected pedicle-screw-rod constructs per level. Sensing devices were attached to the rods between each pedicle screw pair and the loads were continuously monitored over 16 weeks. After euthanasia, the spines were biomechanically tested for their range of motion and high-resolution CT scans were performed to confirm the fusion success. After an initial increase in implant load until reaching a maximum (100 %) at approximately week 4, eleven out of twelve sensors measured a constant decrease in implant load to 52 ± 9 % at euthanasia. One sensor measurement was compromised by newly forming bone growing against the sensor clamp. Bridging bone at each facet and minor remnant segmental motion (<0.7°) confirmed the fusion of all motion segments. Data obtained by continuous measurement of implant loading of spinal screw-rod constructs enables objective monitoring of spinal fusion progression. The sensor concept provides valuable real-time information, offering quantifiable data as an alternative to traditional imaging techniques. However, the design of the current sensor concept needs to be matured, tailored to, and validated for the human spine.

Continuous Rod Load Monitoring to Assess Spinal Fusion Status-Pilot In Vivo Data in Sheep.

Background and Objectives: Spinal fusion is an effective and widely accepted intervention. However, complications such as non-unions and hardware failures are frequently observed. Radiologic imaging and physical examination are still the gold standards in the assessment of spinal fusion, despite multiple limitations including radiation exposure and subjective image interpretation. Furthermore, current diagnostic methods only allow fusion assessment at certain time points and require the patient's presence at the hospital or medical practice. A recently introduced implantable sensor system for continuous and wireless implant load monitoring in trauma applications carries the potential to overcome these drawbacks, but transferability of the principle to the spine has not been demonstrated yet. Materials and Methods: The existing trauma sensor was modified for attachment to a standard pedicle-screw-rod system. Two lumbar segments (L2 to L4) of one Swiss white alpine sheep were asymmetrically instrumented. After facetectomy, three sensors were attached to the rods between each screw pair and activated for measurement. The sheep was euthanized 16 weeks postoperatively. After radiological assessment the spine was explanted and loaded in flexion-extension to determine the range of motion of the spinal segments. Sensor data were compared with mechanical test results and radiologic findings. Results: The sensors measured physiological rod loading autonomously over the observation period and delivered the data daily to bonded smartphones. At euthanasia the relative rod load dropped to 67% of the respective maximum value for the L23 segment and to 30% for the L34 segment. In agreement, the total range of motion of both operated segments was lower compared to an intact reference segment (L23: 0.57°; L34: 0.49°; intact L45: 4.17°). Radiologic assessment revealed fusion mass in the facet joint gaps and bilateral bridging bone around the joints at both operated segments. Conclusions: Observations of this single-case study confirm the basic ability of continuous rod load measurement to resolve the spinal fusion process as indicated by a declining rod load with progressing bone fusion. A strong clinical potential of such technology is eminent, but further data must be collected for final proof of principle.

PMMA-Cement-PLIF Is Safe and Effective as a Single-Stage Posterior Procedure in Treating Pyogenic Erosive Lumbar Spondylodiscitis-A Single-Center Retrospective Study of 73 Cases.

BACKGROUND: Surgical treatment for erosive pyogenic spondylodiscitis of the lumbar spine is challenging as, following debridement of the intervertebral and bony abscess, a large and irregular defect is created. Sufficient defect reconstruction with conventional implants using a posterior approach is often impossible. Therefore, we developed the "Cement-PLIF", a single-stage posterior lumbar procedure, combining posterior lumbar interbody fusion (PLIF) with defect-filling using antibiotic-loaded polymethylmethacrylate (PMMA). This study first describes and evaluates the procedure's efficacy, safety, and infection eradication rate. Radiological implant stability, bone-regeneration, sagittal profile reconstruction, procedure-related complications, and pre-existing comorbidities were further analyzed. METHODS: A retrospective cohort study analyzing 73 consecutive patients with a minimum of a one-year follow-up from 2000-2017. Patient-reported pain levels and improvement in infectious serological parameters evaluated the clinical outcome. Sagittal profile reconstruction, anterior bone-regeneration, and posterior fusion were analyzed in a.p. and lateral radiographs. A Kaplan-Meier analysis was used to determine the impact of pre-existing comorbidities on mortality. Pre-existing comorbidities were quantified using the Charlson-Comorbidity Index (CCI). RESULTS: Mean follow-up was 3.3 (range: 1-16; ±3.2) years. There was no evidence of infection persistence in all patients at the one-year follow-up. One patient underwent revision surgery for early local infection recurrence (1.4%). Five (6.9%) patients required an early secondary intervention at the same level due to minor complications. Radiological follow-up revealed implant stability in 70/73 (95.9%) cases. Successful sagittal reconstruction was demonstrated in all patients (p < 0.001). There was a significant correlation between Kaplan-Meier survival and the number of pre-existing comorbidities (24-months-survival: CCI ≤ 3: 100%; CCI ≥ 3: 84.6%; p = 0.005). CONCLUSIONS: The Cement-PLIF procedure for pyogenic erosive spondylodiscitis is an effective and safe treatment as evaluated by infection elimination, clinical outcome, restoration, and maintenance of stability and sagittal alignment.

Variations in management of A3 and A4 cervical spine fractures as designated by the AO Spine Subaxial Injury Classification System.

OBJECTIVE: Optimal management of A3 and A4 cervical spine fractures, as defined by the AO Spine Subaxial Injury Classification System, remains controversial. The objectives of this study were to determine whether significant management variations exist with respect to 1) fracture location across the upper, middle, and lower subaxial cervical spine and 2) geographic region, experience, or specialty. METHODS: A survey was internationally distributed to 272 AO Spine members across six geographic regions (North America, South America, Europe, Africa, Asia, and the Middle East). Participants' management of A3 and A4 subaxial cervical fractures across cervical regions was assessed in four clinical scenarios. Key characteristics considered in the vignettes included degree of neurological deficit, pain severity, cervical spine stability, presence of comorbidities, and fitness for surgery. Respondents were also directly asked about their preferences for operative management and misalignment acceptance across the subaxial cervical spine. RESULTS: In total, 155 (57.0%) participants completed the survey. Pooled analysis demonstrated that surgeons were more likely to offer operative intervention for both A3 (p < 0.001) and A4 (p < 0.001) fractures located at the cervicothoracic junction compared with fractures at the upper or middle subaxial cervical regions. There were no significant variations in management for junctional incomplete (p = 0.116) or complete (p = 0.342) burst fractures between geographic regions. Surgeons with more than 10 years of experience were more likely to operatively manage A3 (p < 0.001) and A4 (p < 0.001) fractures than their younger counterparts. Neurosurgeons were more likely to offer surgical stabilization of A3 (p < 0.001) and A4 (p < 0.001) fractures than their orthopedic colleagues. Clinicians from both specialties agreed regarding their preference for fixation of lower junctional A3 (p = 0.866) and A4 (p = 0.368) fractures. Overall, surgical fixation was recommended more often for A4 than A3 fractures in all four scenarios (p < 0.001). CONCLUSIONS: The subaxial cervical spine should not be considered a single unified entity. Both A3 and A4 fracture subtypes were more likely to be surgically managed at the cervicothoracic junction than the upper or middle subaxial cervical regions. The authors also determined that treatment strategies for A3 and A4 subaxial cervical spine fractures varied significantly, with the latter demonstrating a greater likelihood of operative management. These findings should be reflected in future subaxial cervical spine trauma algorithms.

The "Spinal Metastasis Invasiveness Index": A Novel Scoring System to Assess Surgical Invasiveness.

STUDY DESIGN: Retrospective review. OBJECTIVE: The aim of this study was to develop a surgical invasiveness index for metastatic spine tumor surgery (MSTS) that can serve as a standardized tool in predicting intraoperative blood loss and surgical duration; for the purpose of ascertaining resource requirements and aiding in patient education. SUMMARY OF BACKGROUND DATA: Magnitude of surgery is important in the metastatic spine disease (MSD) population since these patients have a continuing postoperative oncological process; a consideration that must be taken into account to maintain or improve quality of life. Surgical invasiveness indices have been established for general spine surgery, adult deformity, and cervical deformity, but not yet for spinal metastasis. METHODS: Demographic, oncological, and procedural data were collected from consecutive patients that underwent MSTS. Binary logistic regression, using median values for surgical duration and intraoperative estimated blood loss (EBL), was used to determine statistical significance of variables to be included in the "spinal metastasis invasiveness index" (SMII). The corresponding weightage of each of these variables was agreed upon by experienced spine surgeons. Multivariable regression analysis was used to predict operative time and EBL while controlling for demographical, procedural, and oncological characteristics. RESULTS: Two hundred and sixty-one MSD patients were included with a mean age of 59.7-years and near equal sex distribution. The SMII strongly predicted extended surgical duration (R2 = 0.28, P < 0.001) and high intraoperative blood loss (R2 = 0.18, P < 0.001). When compared to a previously established surgical invasiveness index, the SMII accounted for more variability in the outcomes. For every unit increase in score, there was a 42-mL increase in mean blood loss (P < 0.001) and 5-minute increase in mean operative time (P < 0.001). CONCLUSION: Long surgical duration and high blood loss were strongly predicted by the newly developed SMII. The use of the SMII may aid in preoperative risk assessment with the goal of improving patient outcomes and quality of life.Level of Evidence: 4.

The Current Status of Spinal Posttraumatic Deformity: A Systematic Review.

STUDY DESIGN: Systematic Review. OBJECTIVE: To systematically analyze the definitions and descriptions in literature of "Spinal Posttraumatic Deformity" (SPTD) in order to support the development of a uniform and comprehensive definition of clinically relevant SPTD. METHODS: A literature search in 11 international databases was performed using "deformity" AND "posttraumatic" and its synonyms. When an original definition or a description of SPTD (Patient factors, Radiological outcomes, Patient Reported Outcome Measurements and Surgical indication) was present the article was included. The retrieved articles were assessed for methodological quality and the presented data was extracted. RESULTS: 46 articles met the inclusion criteria. "Symptomatic SPTD" was mentioned multiple times as an entity, however any description of "symptomatic SPTD" was not found. Pain was mentioned as a key factor in SPTD. Other patient related parameters were (progression of) neurological deficit, bone quality, age, comorbidities and functional disability. Various ways were used to determine the amount of deformity on radiographs. The amount of deformity ranged from not deviant for normal to >30°. Sagittal balance and spinopelvic parameters such as the Pelvic Incidence, Pelvic Tilt and Sacral Slope were taken into account and were used as surgical indicators and preoperative planning. The Visual Analog Scale for pain and the Oswestry Disability Index were used mostly to evaluate surgical intervention. CONCLUSION: A clear-cut definition or consensus is not available in the literature about clinically relevant SPTD. Our research acts as the basis for international efforts for the development of a definition of SPTD.

Epidemiology and injury patterns of aerial sports in Switzerland.

BACKGROUND: Airborne sports have become more popular in recent years. The number of accidents has increased linearly as athletes take increasingly greater risks to experience the adventurous spirit of this kind of sports. AIM: To investigate the variety of injuries in airborne sport accidents, as well as which acute treatment these patients receive, both before and after admission to a level-one-trauma center. METHODS: We performed a retrospective chart analysis at a major level-one-trauma center in Switzerland for 235-patients who were admitted following airborne sports injuries between 2010 and 2017. Patients' demographic data, injury patterns, emergency primary care procedures and intra-hospital care were recorded. RESULTS: Overall, 718-injuries in 235-patients were identified; the spine was the most commonly affected region with 46.5% of injuries (n = 334/718) in 143-patients. In 69-patients (15.5%), the (non-spine) thorax was affected, followed by the lower and upper extremity, pelvis, head/face and abdominal injuries. Eleven-patients had to be intubated at the trauma site. Three patients were resuscitated after onset of pulseless-electrical-activity. Two-patients died in the resuscitation room. In 116-cases, surgery was indicated including 55-emergency surgeries. Another 19 patients (8.1%) were transferred to the intensive care unit. CONCLUSION: Paragliders are most commonly affected, although the highest injury severities were identified for Building, Antenna, Span and Earth-jumping athletes. First responders, treating physicians and pilots should be aware of the risk for potentially serious and life-threatening injury with an in-hospital mortality of 0.9%.

Application of Cytokines of the Bone Morphogenetic Protein (BMP) Family in Spinal Fusion - Effects on the Bone, Intervertebral Disc and Mesenchymal Stromal Cells.

Low back pain is a prevalent socio-economic burden and is often associated with damaged or degenerated intervertebral discs (IVDs). When conservative therapy fails, removal of the IVD (discectomy), followed by intersomatic spinal fusion, is currently the standard practice in clinics. The remaining space is filled with an intersomatic device (cage) and with bone substitutes to achieve disc height compensation and bone fusion. As a complication, in up to 30% of cases, spinal non-fusions result in a painful pseudoarthrosis. Bone morphogenetic proteins (BMPs) have been clinically applied with varied outcomes. Several members of the BMP family, such as BMP2, BMP4, BMP6, BMP7, and BMP9, are known to induce osteogenesis. Questions remain on why hyper-physiological doses of BMPs do not show beneficial effects in certain patients. In this respect, BMP antagonists secreted by mesenchymal cells, which might interfere with or block the action of BMPs, have drawn research attention as possible targets for the enhancement of spinal fusion or the prevention of non-unions. Examples of these antagonists are noggin, gremlin1 and 2, chordin, follistatin, BMP3, and twisted gastrulation. In this review, we discuss current evidence of the osteogenic effects of several members of the BMP family on osteoblasts, IVD cells, and mesenchymal stromal cells. We consider in vitro and in vivo studies performed in human, mouse, rat, and rabbit related to BMP and BMP antagonists in the last two decades. We give insights into the effects that BMP have on the ossification of the spine. Furthermore, the benefits, pitfalls, and possible safety concerns using these cytokines for the improvement of spinal fusion are discussed.

Basic concepts in metal work failure after metastatic spine tumour surgery.

PURPOSE: The development of spinal implants marks a watershed in the evolution of metastatic spine tumour surgery (MSTS), which has evolved from standalone decompressive laminectomy to instrumented stabilization and decompression with reconstruction when necessary. Fusion may not be feasible after MSTS due to poor quality of graft host bed along with adjunct chemotherapy and/or radiotherapy postoperatively. With an increase in the survival of patients with spinal tumours, there is a probability of an increase in the rate of implant failure. This review aims to help establish a clear understanding of implants/constructs used in MSTS and to highlight the fundamental biomechanics of implant/construct failures. METHODS: Published literature on implant failure after spine surgery and MSTS has been reviewed. The evolution of spinal implants and their role in MSTS has been briefly described. The review defines implant/construct failures using radiological parameters that are practical, feasible, and derived from historical descriptions. We have discussed common modes of implant/construct failure after MSTS to allow further understanding, interception, and prevention of catastrophic failure. RESULTS: Implant failure rates in MSTS are in the range of 2-8%. Variability in patterns of failure has been observed based on anatomical region and the type of constructs used. Patients with construct/implant failures may or may not be symptomatic and present either as early (< 3months) or late failures (> 3months). It has been noted that not all the implant failures after MSTS result in revisions. CONCLUSION: Based on the observed radiological criteria and clinical presentations, we have proposed a clinico-radiological classification for implant/construct failure after MSTS.

Short Posterior Stabilization in Combination With Cement Augmentation for the Treatment of Thoracolumbar Fractures and the Effects of Implant Removal.

STUDY DESIGN: Retrospective case series. OBJECTIVE: Short posterior stabilization with vertebroplasty is one treatment option for thoracolumbar burst fractures (AO A3). Whether it avoids progression in segmental kyphosis, especially after implant removal, is unclear. In a retrospective case-control study, its stability and the effect on intervertebral discs with and without implant removal was studied. METHODS: Fifty-nine consecutive patients were treated with bisegmental short posterior instrumentation and additional vertebroplasty of the fractured vertebra. Twenty-nine patients (male/female 17/12; age: 41.7 ± 15.4 years) underwent implant removal. Changes of segmental kyphosis and disc heights between both groups (with and without implant removal) were compared on lateral X-rays preoperative, postoperative, after 1 year and after implant removal. Risk factors for loss of reduction were analyzed. RESULTS: Kyphosis increased up to 12 months after implant removal. The loss of bisegmental correction was 6.0 ± 4.2 (range 0° to 16°) 12 months after implant removal. Risk factors for loss of reduction are younger patient age, fractures of the thoracolumbar junction (Th12), and degree of traumatic kyphosis. Intervertebral discs traversed by the stabilization lose height and don't recover within 1 year after implant removal. Without implant removal, disc height of the lower adjacent level is reduced after 24 months. CONCLUSIONS: Short posterior stabilization in combination with vertebroplasty is a treatment alternative for thoracic and lumbar AO A3 fractures. After implant removal kyphosis increases, predominantly in the segment above the augmented vertebra. Risk factors for loss of reduction include younger age, fractures of the thoracolumbar junction (T12), and higher fracture kyphosis.

Intervertebral disc response to stem cell treatment is conditioned by disc state and cell carrier: An ex vivo study.

In vitro and in vivo studies evidenced that mesenchymal stem cells (MSCs) contribute to intervertebral disc (IVD) regeneration by differentiation towards the disc phenotype and matrix synthesis and/or by paracrine signalling to endogenous cells, thereby promoting a healthier disc phenotype in degenerative discs. The aim of this study was to investigate IVD response to human MSC (hMSC) treatment based on the disc degenerative state and hMSC carrier. Bovine caudal IVDs with endplates were cultured in a bioreactor under simulated physiological (0.1 Hz load and sufficient glucose) or degenerative (10 Hz load and limited glucose) conditions for 7 days. Discs were partially nucleotomised, restored with hMSCs in either fibrin gel or saline solution and cultured under physiological conditions for 7 days. Controls included fibrin and saline without hMSCs. Cell viability, histology, disc height, and gene expression analyses were performed to evaluate regeneration. hMSCs in fibrin were viable and homogenously distributed following 7 days of culture under dynamic loading in partially nucleotomised discs. IVD response to hMSCs was conditioned by both disc degenerative state and hMSC carrier. The effect of the regenerative treatment was stronger on simulated-degenerative discs than on simulated-physiological discs. hMSCs in fibrin induced a superior anabolic response in degenerative IVDs compared with fibrin alone, thus suggesting an added value of the cellular therapy compared with an acellular solution. When comparing fibrin and saline as a hMSC carrier, a significantly higher anabolic response was observed in IVDs treated with hMSCs in fibrin. Moreover, it was found that the degenerative state of the disc influenced hMSC differentiation. Indeed, a significantly higher expression of specific discogenic markers (ACAN and CA12) was observed in hMSCs implanted into physiological discs than in those implanted into degenerative discs. In conclusion, host disc cells and donor hMSC response depend on the degenerative state of the host disc and carrier used for hMSC delivery, and these two aspects need to be considered for a successful translation of hMSC therapies for the treatment of IVD degeneration.

Lavage prior to vertebral augmentation reduces the risk for cement leakage.

PURPOSE: This study aimed at assessing the cement leakage rate and the filling pattern in patients treated with vertebroplasty, kyphoplasty and stentoplasty with and without a newly developed lavage technique. STUDY DESIGN: Retrospective clinical case-control study. METHODS: A newly developed bipedicular lavage technique prior to cement application was applied in 64 patients (45.1 %) with 116 vertebrae, ("lavage" group). A conventional bipedicular cement injection technique was used in 78 patients (54.9 %) with 99 levels ("controls"). The outcome measures were filling patterns and leakage rates. RESULTS: The overall leakage rate (venous, cortical defect, intradiscal) was 37.9 % in the lavage and 83.8 % in the control group (p < 0.001). Venous leakage (lavage 12.9 % vs. controls 31.3 %; p = 0.001) and cortical defect leakage (lavage 17.2 % vs. controls 63.3 %; p < 0.001) were significantly lower in the lavage group compared to "controls," whereas intradiscal leakages were similar in both groups (lavage 12.1 % vs. controls 15.2 %; p = 0.51). For venous leakage multivariate logistic regression analysis showed lavage to be the only independent predictor. Lavage was associated with 0.33-times (95 % CI 0.16-0.65; p = 0.001) lower likelihood for leakage in compared to controls. CONCLUSIONS: Vertebral body lavage prior to cement augmentation is a safe technique to reduce cement leakage in a clinical setting and has the potential to prevent pulmonary fat embolism. Moreover, a better filling pattern can be achieved.

Assessment of the Breakaway Torque at the Posterior Pelvic Ring in Human Cadavers.

PURPOSE: To enhance the diminished screw purchase in cancellous, osteoporotic bone following the fixation of posterior pelvic ring injuries by iliosacral screws an increased bone-implant contact area using modificated screws, techniques or bone cement may become necessary. The aim of the study was to identify sites within the pathway of iliosacral screws requiring modifications of the local bone or the design of instrumentations placed at this site. MATERIALS AND METHODS: The breakaway torque was measured mechanically at the iliosacral joint ("ISJ"), the sacral lateral mass ("SLM") and the center of the S1 ("CS1"), at a superior and an inferior site under fluoroscopic control on five human cadaveric specimens (3 female; mean age 87 years, range: 76-99) using the DensiProbe™Spine device. RESULTS: The measured median (range) breakaway torque was 0.63 Nm (0.31-2.52) at the "iliosacral joint", 0.14 Nm (0.05-1.22) at the "sacral lateral mass", 0.57 Nm (0.05-1.42) at the "S1 center." The "sacral lateral mass" breakaway torque was lower than compared to that at the "iliosacral joint" (p < .001) or "S1 center" (p < .001). The median (range) breakaway torque measured at all superior measurement points was 0.52 Nm (0.10-2.52), and 0.48 Nm (0.05-1.18) at all inferior sites. The observed difference was statistically significant (p < .05). CONCLUSIONS: The lateral mass of the sacrum provides the lowest bone quality for implant anchorage. Iliosacral screws should be placed as superior as safely possible, should bridge the iliosacral joint and may allow for cement application at the lateral mass of the sacrum through perforations.

Radiographic and safety details of vertebral body stenting: results from a multicenter chart review.

BACKGROUND: Up to one third of BKP treated cases shows no appreciable height restoration due to loss of both restored height and kyphotic realignment after balloon deflation. This shortcoming has called for an improved method that maintains the height and realignment reached by the fully inflated balloon until stabilization of the vertebral body by PMMA-based cementation. Restoration of the physiological vertebral body height for pain relief and for preventing further fractures of adjacent and distant vertebral bodies must be the main aim for such a method. A new vertebral body stenting system (VBS) stabilizes the vertebral body after balloon deflation until cementation. The radiographic and safety results of the first 100 cases where VBS was applied are presented. METHODS: During the planning phase of an ongoing international multicenter RCT, radiographic, procedural and followup details were retrospectively transcribed from charts and xrays for developing and testing the case report forms. Radiographs were centrally assessed at the institution of the first/senior author. RESULTS: 100 patients (62 with osteoporosis) with a total of 103 fractured vertebral bodies were treated with the VBS system. 49 were females with a mean age of 73.2 years; males were 66.7 years old. The mean preoperative anterior-middle-posterior heights were 20.3-17.6-28.0 mm, respectively. The mean local kyphotic angle was 13.1°. The mean preoperative Beck Index (anterior edge height/posterior edge height) was 0.73, the mean alternative Beck Index (middle height/posterior edge height) was 0.63. The mean postoperative heights were restored to 24.5-24.6-30.4 mm, respectively. The mean local kyphotic angle was reduced to 8.9°. The mean postoperative Beck Index was 0.81, the mean alternative one was 0.82. The overall extrusion rate was 29.1%, the symptomatic one was 1%. In the osteoporosis subgroup there were 23.8% extrusions. Within the three months followup interval there were 9% of adjacent and 4% of remote new fractures, all in the osteoporotic group. CONCLUSIONS: VBS showed its strengths especially in realignment of crush and biconcave fractures. Given that fracture mobility is present, the realignment potential is sound and increases with the severity of preoperative vertebral body deformation.

Table-mounted ring retractor for consistent visualization in endoscopy-assisted anterior reconstruction of burst fractures of the thoracolumbar junction.

The authors tested an autoclavable external ring retractor, fixed to the operation table, for the endoscopic reconstruction of anterior column injuries of the thoracolumbar junction. It served as a retractor for the diaphragm, and offered a stable support for the scope and other instruments, making an assistant superfluous. Moreover, it allowed bimanual manipulation. Of course, the two-dimensional image, provided by the scope, necessitated proper eye-hand coordination. Twenty-eight consecutive patients underwent either a monosegmental (n = 10) or a bisegmental (n = 18) anterior stabilization in the area Th11L1. Three portals were necessary, but an assistant was not needed. The overall (mean +/- SD) operating time was 196 +/- 56 min, the blood loss was 804 +/- 719 mL. Intraoperatively, one epidural bleeding and a single screw cut-out occurred. All complications were managed endoscopically. Postoperatively, evacuation of a haemothorax (n = 1) was necessary. In all patients, wounds and fractures healed uneventfully. The combination of the endoscopic technique and the retractor system was feasible, successful, safe, and time efficient. Moreover, it allowed for anterior instrumentation of thoracolumbar fractures by a single surgeon. It became the standard approach in the authors' department.

Complications related to cement leakage in sacroplasty.

Data concerning the safety of sacroplasty in terms of cement leakage is scarce. Frequency, distribution patterns and clinical consequences of cement leakage were assessed in 33 patients (28 female, mean age: 74 +/- 10 yrs; bilateral SIF: n = 30, 63 sacroplasties) treated with sacroplasty between 06/2003 and 11/2010 in a retrospective study using patients' records, operative notes and postoperative radiographs. Cement leakage was noted within the fracture gap (27%), into veins (6%), neuroforamina (3%) or in the intervertebral disc space L5/S1 (2%). In one patient, cement leakage into the fracture gap led to unilateral radiculopathy of the 5th lumbar nerve root. Leakage into the fracture gap is at high risk of affecting the 5th lumbar nerve root due to the special course of its ventral branch over the sacral promontory. The risks of cement leakage with neurological impairment should be explained to patients.

Safety, effectiveness and predictors for early reoperation in therapeutic and prophylactic vertebroplasty: short-term results of a prospective case series of patients with osteoporotic vertebral fractures.

INTRODUCTION: Vertebroplasty (VP) is a cost-efficient alternative to kyphoplasty; however, regarding safety and vertebral body (VB) height restoration, it is considered inferior. We assessed the safety and efficacy of VP in alleviating pain, improving quality of life (QoL) and restoring alignment. METHODS: In a prospective monocenter case series from May 2007 until July 2008, there were 1,408 vertebroplasties performed during 319 interventions in 306 patients with traumatic, lytic and osteoporotic fractures. The 249 interventions in 233 patients performed because of osteoporotic vertebral fractures were analyzed regarding demographics, treatment and radiographic details, pain alleviation (VAS), QoL improvement (NASS and EQ-5D), complications and predictors for new fractures requiring a reoperation. RESULTS: The osteoporotic patient sample consisted of 76.7% (179) females with a median age of 80 years. A total of 54 males had a median age of 77 years. On average, there were 1.8 VBs fractured and 5 VBs treated. The preoperative pain was assessed by the visual analog scale (VAS) and decreased from 54.9 to 40.4 pts after 2 months and 31.2 pts after 6 months. Accordingly, the QoL on the EQ-5D measure (-0.6 to 1) improved from 0.35 pts before surgery to 0.56 pts after 2 and to 0.68 pts after 6 months. The preoperative Beck Index (anterior height/posterior height) improved from a mean of 0.64 preoperative to 0.76 postoperative, remained stable at 2 months and slightly deteriorated to 0.72 at 6 months postoperatively. There were cement leakages in 26% of the fractured VBs and in 1.4% of the prophylactically cemented VBs; there were symptoms in 4.3%, and most of them were temporary hypotension and one pulmonary cement embolism that remained asymptomatic. The univariate regression model revealed a tendency for a reduced risk for new or refractures on radiographs (OR = 2.61, 95% CI 0.92-7.38, p = 0.12) and reoperations (OR = 2.9, 95% CI 0.94-8.949, p = 0.1) when prophylactic augmentation was performed. The final multivariate regression model revealed male patients to have an about three times higher refracture risk (radiographic) (OR = 2.78, p = 0.02) at 6 months after surgery. Patients with a lumbar index fracture had an about three to five times higher refracture/reoperation risk than patients with a thoracic (OR = 0.33/0.35, p = 0.009/0.01) or thoracolumbar (OR = 0.32/0.22, p = 0.099/0.01) index fracture. CONCLUSION: If routinely used, VP is a safe and efficacious treatment option for osteoporotic vertebral fractures with regard to pain relief and improvement of the QoL. Even segmental realignment can be partially achieved with proper patient positioning. Certain patient or fracture characteristics increase the risk for early radiographic refractures or new fractures, or a reoperation; a consequent prophylactic augmentation showed protective tendencies, but the study was underpowered for a final conclusion.

Less invasive lumbopelvic stabilization of posterior pelvic ring instability: technique and preliminary results.

BACKGROUND: Lumbopelvic distraction stabilization with (triangular osteosynthesis) or without additional iliosacral screw allows anatomic reduction of the posterior pelvic ring after severely displaced sacral fractures, correction or resection osteotomies of malunions, respectively, septic sacroiliitis and permits early weight bearing. However, this technique is complicated by wound necrosis or infection in up to 20% to 30%. We describe our experience with a less invasive technique. METHODS: The presented technique was performed in a consecutive series (December 2006 to October 2009) of 10 patients (mean age: 47 years, 23-85 years; 5 men). Posterior pelvic ring instability was due to severely displaced vertical shear injuries of type C1/3.3 (6/10), delayed union 2 months after bilateral C 3.3 (1/10) fractures, and malunion 6 months after unilateral vertical shear injuries C 1.3 (1/10), occurred after resection of the iliosacral joint for treatment of spinal tuberculosis (1/10) or was related to a early loss of reduction of a type C 1.3 pelvic ring injury (1/10). Patients were prospectively evaluated for the occurrence of wound-healing disorders with a median follow-up of 9 months (range, 5-33). RESULTS: The median duration of the hospital stay was 35 days (range, 16-57). One 85-year-old patient died 1 year after lumbopelvic stabilization for reasons unrelated to the surgical treatment. In the postoperative course, no wound-healing disorders or infections were observed, and in all cases, the soft tissues and the bone healed. Five of 10 removal of the lumbopelvic fixation was performed at a median of 8 months (range, 8-20) after stabilization to prevent sacroiliac arthrodesis or to mobilize the lumbar spine after the unilateral lumbopelvic stabilization. The indication for hardware removal was not related to wound disorders. CONCLUSION: The presented technique respects the lumbar anatomy and provides the access required for lumbopelvic stabilization, while having the potential to decrease or even prevent postoperative wound disorders if combined with a polyaxial low-profile system. The low number of cases presented may, however, limit the relevance of the conclusions in cases of severe Morell-Lavallé lesions with skin disorders.

Could full-body digital X-ray (LODOX-Statscan) screening in trauma challenge conventional radiography?

BACKGROUND: ATLS Guidelines recommend single plain radiography of the chest and pelvis as part of the primary survey. Such isolated radiographs, usually obtained by bedside machines, can result in limited, low-quality studies that can adversely affect management. A new digital, low-radiation imaging device, the "Lodox Statscan" (LS), provides full-body anterior and lateral views based on enhanced linear slot-scanning technology in just over 5 minutes. We have the first LS in Europe at our facility. The aim of this study was to compare LS with computed tomographic (CT) scanning, as the gold standard, to determine the sensitivity of LS investigation in detecting injuries to the chest, thoracolumbar spine, and pelvis from our own experience, and to compare our findings with those of conventional radiography in the literature. METHODS: We performed a retrospective chart analysis of 245 patients with multiple injuries examined by full-body LS imaging and CT scans between October 1, 2006 and October 1, 2007 at our facility. Patients under the age of 16 years were not included. LS and CT images of chest injuries, injuries to the thoracolumbar spine, and fractures of the pelvis were compared. At our facility, we no longer perform plain radiography for C-spine and head injury, but perform CT scans according to the Canadian rules. Findings with LS were also compared with those reported for conventional radiography in the literature. RESULTS: Compared with CT scanning, sensitivity and specificity of full-body digital X-ray of blunt chest trauma were 57% and 100%, respectively, thoracic spinal injury 43% and 100%, lumbar spine lesions 74% and 100%, and pelvic injury 72% and 99%. The positive and negative predictive value of LS imaging were 99% and 90% for blunt chest trauma, 100% and 93% for overall spinal injuries, and 90% and 97% for pelvic injuries. CONCLUSION: Full-body radiography with LS visualizes skeletal, chest, and pelvic pathologies "all-in-one." This low-radiation technology detected chest, thoracolumbar spine, and pelvic injuries with an overall sensitivity of 62% and a specificity of 99%. Compared with figures in the literature, LS was more accurate than conventional X-rays. A prospective randomized study is warranted to support these data.