Does the intraoperative 3D-flat panel control of the planned implant position lead to an optimization and increased in safety in the anatomically demanding region C1/2?

BACKGROUND: The aim of this study was to evaluate the applicability and advantages of intraoperative imaging using a 3D flat panel in the treatment of C1/2 instabilities. MATERIALS: Prospective single-centered study including surgeries at the upper cervical spine between 06/2016 and 12/2018. Intraoperatively thin K-wires were placed under 2D fluoroscopic control. Then an intraoperative 3D-scan was carried out. The image quality was assessed based on a numeric analogue scale (NAS) from 0 to 10 (0 = worst quality, 10 = perfect quality) and the time for the 3D-scan was measured. Additionally, the wire positions were evaluated regarding malpositions. RESULTS: A total of 58 patients were included (33f, 25 m, average age 75.2 years, r.:18-95) with pathologies of C2: 45 type II fractures according to Anderson/D'Alonzo with or without arthrosis of C1/2, 2 Unhappy triad of C1/2 (Odontoid fracture Type II, anterior or posterior C1 arch-fracture, Arthrosis C1/2) 4 pathological fractures, 3 pseudarthroses, 3 instabilities of C1/2 because of rheumatoid arthritis, 1 C2 arch fracture). 36 patients were treated from anterior [29 AOTAF (combined anterior odontoid and transarticular C1/2 screw fixation), 6 lag screws, 1 cement augmented lag screw] and 22 patients from posterior (regarding to Goel/Harms). The median image quality was 8.2 (r.: 6-10). In 41 patients (70.7%) the image quality was 8 or higher and in none of the patients below 6. All of those 17 patients the image quality below 8 (NAS 7 = 16; 27.6%, NAS 6 = 1, 1.7%), had dental implants. A total of 148 wires were analyzed. 133 (89.9%) showed a correct positioning. In the other 15 (10.1%) cases a repositioning had to be done (n = 8; 5.4%) or it had to be drawn back (n = 7; 4.7%). A repositioning was possible in all cases. The implementation of an intraoperative 3D-Scan took an average of 267 s (r.: 232-310 s). No technical problems occurred. CONCLUSION: Intraoperative 3D imaging in the upper cervical spine is fast and easy to perform with sufficient image quality in all patients. Potential malposition of the primary screw canal can be detected by initial wire positioning before the Scan. The intraoperative correction was possible in all patients. Trial registration German Trials Register (Registered 10 August 2021, DRKS00026644-Trial registration: German Trials Register (Registered 10 August 2021, DRKS00026644- https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00026644 ).

[Spinal deformity in neurofibromatosis type 1]. / Wirbelsäulendeformitäten bei Neurofibromatose Typ 1.

BACKGROUND: With a prevalence of up to 60%, spinal deformity represents the most common skeletal manifestation of neurofibromatosis type 1. The deformity can occur as a non-dystrophic or as a less common dystrophic type. This distinction is of great relevance because the therapeutic strategy is completely different in each case. NON-DYSTROPHIC TYPE: The non-dystrophic type can be treated like idiopathic scoliosis due to the comparable behavior of both entities. However, care must be taken regarding the so-called modulation. Modulation describes the formation of dysplasias of the spine. This will result in a progression behavior as known from the dystrophic type. DYSTROPHIC TYPE: For the dystrophic type, different spinal dysplastic changes are typical. These lead to a rapid progression of deformity and a lack of response to conservative treatment. If untreated, severe and grotesque deformities can arise. This type of deformity requires early surgical intervention, even in childhood. The knowledge about the peculiarities of this disease in general, as well as the typical changes of the spine are prerequisites to managing these often-challenging situations.

[Release of moveable segments after dorsal stabilization : Impact on affected discs]. / Freigabe von Bewegungssegmenten nach dorsaler Stabilisierung : Auswirkung auf die betroffenen Bandscheiben.

BACKGROUND: Bisegmental dorsal stabilization is a common treatment option for instable compression fractures of the thoracolumbar spine; however, it remains unknown to what extent bridging compromises intervertebral discs. OBJECTIVES: The purpose of this study was to determine the disc height and functional features in comparison to healthy intervertebral discs after removal of the dorsal fixator and particularly under consideration of the time span between dorsal stabilization and implant removal (IR). MATERIAL AND METHODS: The IR was performed in 19 patients after an average of 13 months (range 8-24 months) after dorsal stabilization of instable vertebral compression fractures of the thoracolumbar junction and lumbar spine. An additional ventral monosegmental spondylodesis was performed in 10 patients with incomplete burst fractures. Thus, a total of 28 intervertebral discs were temporarily bridged (bridged discs), with an adjacent endplate fracture in 10 (injured discs) and no adjacent bony lesion in 18 discs (healthy discs). The intervertebral discs superior and inferior to the instrumentation were selected as controls (control discs). Standardized conventional lateral radiographs were taken prior to and after IR as well as after 6 months. Additionally, standardized lateral radiographs in flexion and extension were taken. The intervertebral disc height (disc height) was determined by two independent board approved orthopedic observers by measuring the anterior, central and dorsal intervertebral disc spaces on all lateral radiographs as well as the intervertebral disc angles (disc angle) defined by the intervertebral upper and lower endplates in the flexion and extension views. Intradisc function (disc function) was defined as the difference between the disc angle in extension and flexion. The measurements were repeated after 12 months. Univariate analysis was performed using ANOVA and significance was set at p < 0.05. Interobserver and intraobserver comparisons of the disc heights and the disc angles were determined with intraclass correlation coefficients. RESULTS: No significant differences were seen in disc function and disc height between the controls and the bridged discs at all times of measurement; however, injured discs showed a significantly reduced disc height and disc angle in extension compared to healthy discs (p = 0.028 and p = 0.027, respectively). Additionally, patients with IR during the first 12 months had significantly reduced disc heights compared to those patients with delayed IR within the second postoperative year (p = 0.018). Interobserver and intraobserver agreement for disc function was 0.80 (95 % confidence interval CI: 0.68-0.88) and 0.85 (95 % CI 0.76-0.90), respectively. The interobserver and intraobserver correlations for disc height were 0.85 (95 % CI: 0.76-0.90) and 0.93 (95 % CI 0.88-0.95), respectively. CONCLUSION: Bridging of an intervertebral disc with IR within 24 months does not cause immediate loss of disc function or reduction of disc height; however, temporary bridging in combination with an adjacent endplate fracture causes significant reduction of disc height and loss of extension. Additionally, no beneficial effects could be seen by reducing the time span between stabilization and IR to below 12 months.

[Delayed indications for additive ventral treatment of thoracolumbar burst fractures : What correction loss is to be expected]. / Zeitverzögerte Indikationsstellung zur additiv ventralen Versorgung thorakolumbaler Berstungsfrakturen : Welcher Korrekturverlust ist zu erwarten.

INTRODUCTION: There is a general consensus that unstable vertebral body fractures of the thoracolumbar junction with a B type fracture or a high load shear index need to be surgically stabilized, primarily by a dorsal approach. The authors believe that there are indications for an additional ventral spondylodesis in cases of reduction loss or a relevant intervertebral disc lesion in magnetic resonance imaging (MRI) 6 weeks after dorsal stabilization. However, in cases of unstable vertebral fractures it remains unclear if a delayed anterior spondylodesis will lead to unacceptable loss of initial reduction. MATERIAL AND METHODS: A total of 59 patients were included in this study during 2013 and 2014. All patients suffered from a traumatic vertebral fracture of the thoracolumbar junction and were initially treated with a dorsal short segment stabilization. All vertebral body fractures had a load shear index of at least 5 or were B type fractures. An x-ray control was carried out after 2 and 6 weeks and MRI was additionally performed after 6 weeks. An additional ventral spondylodesis was recommended in patients showing a reduction loss of at least 5° and in patients with relevant intervertebral disc lesions. The extent of the reduction loss was analyzed. Other parameters of interest were the fracture level, fracture classification, patient age and surgical technique (e.g. implant, index screw, laminectomy and cement augmentation). RESULTS: The patient collective consisted of 23 women and 36 men (average age 51 years ± 17 years). The mean reduction loss was 5.1° (± 5.2°) after a mean follow-up of 60 days (± 56 days). The reduction loss was significantly higher when polyaxial implants were used compared to monoaxial dorsal fixators (10.8° versus 4.0°, p < 0.001). There was a significantly higher reduction loss in those patients who received a laminectomy (11.3° versus 4.3°, p = 0.01) but there were no significant differences if an index screw was used (4.5° versus 5.3°). Additionally, there was a significantly lower reduction in the subgroup of patients 60 years or older who were stabilized using cement-augmented screws (3.9° versus 11.3°, p = 0.02). The mean reduction loss was 2.8° (± 2.5°) in patients treated with a monoaxial implant, cement-augmented if 60 years or older and without laminectomy (n = 39). There was no significant correlation between reduction loss and the other parameters of interest, such as fracture morphology with classification according to the working group on questions of osteosynthesis (AO) and McCormack or fracture level. CONCLUSION: Delayed indications for an additional ventral spondylodesis in patients with unstable thoracolumbar vertebral fractures and initial dorsal stabilization will cause no relevant reduction loss if monoaxial implants are used and laminectomy can be avoided. Additionally, cement augmentation of the pedicle screws seems to be beneficial in patients 60 years of age or older.

[Indications and limitations of minimally invasive stabilization of metastatic spinal disease]. / Indikation und Grenzen der minimal-invasiven Stabilisierung der metastatisch befallenen Wirbelsäule.

The number of patients with symptomatic metastases increases from year to year. Especially spinal metastases often lead to severe pain which often cannot be treated adequately by conservative treatment. Surgeons are confronted with the risk of instability, pathological fractures and neurological failure and the surgical treatment necessary in most cases is nowadays becoming an even greater challenge. The surgical procedure has changed considerably in recent years. The therapy is patient-individualized, the selection of implants and technology is adapted to the physical condition of the patient and the progression of the underlying disease. The main targets of the surgical treatment of spinal metastases have to be sufficient pain reduction with restoration of mobility as well as with the prevention of neurological deficits caused by progressive osteolysis. There are two minimally invasive stabilization procedures which can basically be applied. Under certain circumstances a single kyphoplasty/vertebroplasty procedure can be sufficient, in contrast to the possibility of short or long percutaneous posterior stabilization in combination with selective decompression of neural structures. These percutaneous surgical procedures currently have an important place in the surgical treatment of spinal metastases. The advantages are a less traumatic intervention for patients with advanced malignant diseases and poor general condition. Low intraoperative loss of blood means less intraoperative stress for the patient and minor surgical approaches lead to rapid mobilization and effective pain relief. As a result the hospital stay is shorter, adjuvant therapy can be started earlier and patients can be discharged sooner.

Point-of-care lactate and creatinine analysis for sick obstetric patients at Queen Elizabeth Central Hospital in Blantyre, Malawi: A feasibility study.

BACKGROUND: To achieve good outcomes in critically ill obstetric patients, it is necessary to identify organ dysfunction rapidly so that life-saving interventions can be appropriately commenced. However, timely access to clinical chemistry results is problematic, even in referral institutions, in the sub-Saharan African region. Reliable point-of-care tests licensed for clinical use are now available for lactate and creatinine. AIM: We aimed to assess whether implementation of point-of-care testing for lactate and creatinine is feasible in the obstetric unit at the Queen Elizabeth Central Hospital (QECH) in Blantyre, Malawi, by obtaining the opinions of clinical staff on the use of these tests in practice. METHODS: During a two-month evaluation period nurse-midwives, medical interns, clinical officers, registrars, and consultants were given the opportunity to use StatStrip® and StatSensor® (Nova Biomedical, Waltham, USA) devices, for lactate and creatinine estimation, as part of their routine clinical practice in the obstetric unit. They were subsequently asked to complete a short questionnaire. RESULTS: Thirty-seven questionnaires were returned by participants: 22 from nurse-midwives and the remainder from clinicians. The mean satisfaction score for the devices was 7.6/10 amongst clinicians and 8.0/10 amongst nurse-midwives. The majority of participants stated that the obstetric high dependency unit (HDU) was the most suitable location for the devices. For lactate, 31 participants strongly agreed that testing should be continued and 24 strongly agreed that it would influence patient management. For creatinine, 29 strongly agreed that testing should be continued and 28 strongly agreed that it would influence their patient management. Twenty participants strongly agreed that they trust point-of-care devices. CONCLUSIONS: Point-of-care clinical chemistry testing was feasible, practical, and well received by staff, and was considered to have a useful role to play in the clinical care of sick obstetric patients at this referral centre.

Arthroscopic-assisted simultaneous reconstruction of the posterior cruciate ligament and the lateral collateral ligament using hamstrings and absorbable screws.

Arthroscopic-assisted simultaneous reconstruction of the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL) using hamstring tendon grafts is described. The femoral tunnel is drilled through an incision over the medial femoral condyle and the tibial tunnel through the same skin incision used for harvesting the tendon graft. PCL reconstruction is performed using a 4-strand hamstring tendon graft and absorbable screw fixation. The tendon of the semitendinosus muscle of the uninvolved knee is used as a lateral loop for LCL reconstruction. After pulling the transplant through the fibular head, femoral fixation of the loop is made with an absorbable screw.

3D-based navigation in posterior stabilisations of the cervical and thoracic spine: problems and benefits. Results of 451 screws.

INTRODUCTION: Navigated procedures in spinal surgery have been established due to an increasing demand for precision. Especially, 3D C-arms connected to navigation systems are being used more often and can be utilised intraoperatively for the planning and controlling of screw positions. This prospective study analyses our experiences with 3D-based navigation in posterior stabilisations in the cervical and thoracic spine. METHODS: A 3D C-Arm (Ziehm Vision Vario 3D(®)) was connected to a navigation system (VectorVision, Brainlab(®)) and used for the placement of, in total, 451 screws among 67 patients. Of those, 14 patients had to undergo operations in the cervical and 53 in the thoracic spine. Postoperatively, the positioning was observed with computed tomography (CT). RESULTS: The application time is approximately 6 min. In total, 354/451 (78.5%) screws could be inserted assisted with navigation, and 272/451 (60.3%) were controlled intraoperatively. Regarding the cervical spine, in 87.1% (61/70) of the screws, the navigation procedure was uneventful. The positioning of 63.2% (43/68) of the screws was checked intraoperatively. In the upper thoracic spine, 77% (293/381) could be placed with navigation and 59.6% (227/381) were controlled intraoperatively. Occasionally, the scanning setup was problematic. Correct placement was seen in 92.7% of screws; for the remaining screws, no revision was needed. CONCLUSIONS: Intraoperative 3D imaging navigation for posterior spinal stabilisations is technically feasible and reliable in clinical use. The image quality depends on the individual bone density. With undisturbed visibility of the vertebral body, the reliability of 3D-based navigation is comparable to that of CT-based procedures. Additionally, it has the advantage of skipping the preoperative acquisition of data as well as the matching process, with reduced radiation doses.

[Quality of scientific advice to politics. Lecture at the Berlin-Brandenburg Academy of Science and Humanities]. / Was ist gute Wissenschaftliche Politikberatung? Akademievorlesung bei der Berlin-Brandenburgischen Akademie der Wissenschaften.

Scientific advice to politics is a primary function of governmental research. The advisory process is, in the ideal situation, a collective duty of science and politics. The final decision rests ultimately with politicians. An understanding of the differences between science and politics is necessary for successfully providing advice to politicians. The requirements necessary to allow politics to substantially follow the advice of scientists are multifarious. The first of these is trust from the side of politics and the public and from the side of science competitive research, respect and communication skills, neutrality and integrity. From these requirements it is possible to derive criteria for quality assurance in advice to politics. The maintenance of scientific expertise at the competitive international level demands independent, qualified and adequately financed research. Governmental institutes have an antenna function: they have to recognize in good time whether risks are increasing, whether the government has to be informed and whether there is a need for action. The continuing maintenance of excellence requires measures of quality assurance at all levels. Evidence for the quality of advice to politics can, for example, be found in the good reputation of an institution and its prominent representatives. Success in research is an indirect quality criterion that can be and should be measured to a certain extent. The influence of advisory activities on political decisions is direct evidence for the quality of the advice. A classic example of highly successful policy advice is the development of the German AIDS policy.

[Computer-aided discectomy and corpectomy in anterior reconstruction of the injured thoracolumbar spine. A prospective, controlled clinical trial]. / Navigationsgestützte Rekonstruktion der vorderen Säule bei Verletzungen im Brustwirbel- und thorakolumbalen Ubergangsbereich. Eine prospektive, kontrollierte klinische Studie.

BACKGROUND: In anterior reconstruction of the unstable thoracolumbar spine, discectomy and corpectomy are technically demanding steps requiring maximal surgical precision. This study investigated the feasibility of computer-aided guidance for discectomy and corpectomy. It also analysed the precision, advantages, and disadvantages of the procedure. PATIENTS AND METHODS: Vertebral body fractures of the non-osteoporotic thoracolumbar spine addressed by discectomy/corpectomy and subsequent implant interposition (cage, tricortical strut graft) for anterior reconstruction were included. All surgical steps were done under endoscopic assistance. In the trial group, discectomy and corpectomy were performed with computer-aided guidance; in the control group, no computer navigation was used. The time required for surgery was noted. To assess surgical precision, decentralization of the implant in the frontal plane was measured in postoperative x-rays and computed tomography. Additionally, parallel alignment of vertebral body end plates with the implant was evaluated. RESULTS: The trial group (TG) consisted of 16 patients, and the control group (CG) of 10 patients. Fractures were localized between T10 and L1 in TG, and between T9 and L1 in CG. Operating time was significantly shorter in CG: 104+/-28 min compared with 229+/-64 min in TG (p<0.0005). In contrast, data on surgical precision showed no statistically significant differences between the 2 groups for either decentralization or parallel endplate alignment of implants. Remarkably, for CG we noted 2 cases of cage subsidence into an adjacent end plate, whereas for TG this was noted in only 1 case. However, this difference was not statistically significant. CONCLUSION: Computer-aided guidance for anterior reconstruction of the thoracolumbar spine is a technically feasible option that may help in performing discectomy and corpectomy. However, this technique significantly prolongs the operating time. There were no differences in the precision of implant positioning between the groups. However, during discectomy the use of computer navigation may possibly add to the protection of adjacent end plates.

[Differentiated therapy in necrotizing fasciitis of three extremities]. / Differenzierte Therapie bei nekrotisierender Fasziitis dreier Extremitäten.

AIM: Here we present the clinical symptomatology of and therapy for necrotizing fasciitis. METHOD: The case of a 35-year-old female patient with sustaining fractures of the 5 (th) and 10 (th) thoracic vertebrae and a pulmonary contusion and without any skin lesions is presented. RESULTS: Conventional x-rays and computed tomography revealed stable spine fractures not necessitating surgical intervention. Fifteen days after the accident the patient developed septic conditions. An interdisciplinary search (surgical, neurological, urological, internal medicine) for the septic focus first remained negative. After demarcation of necrotic skin areas at the upper left arm, bilateral necrotizing fasciitis was diagnosed at both thighs and at the lower left leg, necessitating continuous optimisation of the therapeutic strategy. CONCLUSION: Local aggressive surgical therapy in combination with systemic antibiotic administration is the therapy of choice in treatment of the necrotizing fasciitis. It should be performed according to the principle "life before limb". In the presented case the patient recovered and good functional results could be achieved.

[Thoracolumbar spine fractures after conservative and surgical treatment. Dependence of correction loss on fracture level]. / Thorakolumbale Wirbelfrakturen nach konservativer und operativer Behandlung. Abhängigkeit des Korrekturverlustes von der Höhenlokalisation.

QUESTION: This retrospective study presents results after conservative and operative treatment of thoracolumbar fractures as function of its localization. METHODOLOGY: In 2 years 70 patients with A1/A2 fracture were conservatively treated, 38 patients with A3/B/C injury were treated by internal fixtor. For evaluation 3 vertebral sections(Th5-10,Th11-L2,L3-5)were defined. Follow-up took place 1 year after implant removal or end of conservative treatment. RESULTS: The correction-loss was highest in thoracic, lowest in lumbar region. After conservative therapy,correction-loss was located to 3/4 in vertebra itself, after operative treatment especially in adjacent disc spaces. There was no general correlation to complaints. CONCLUSION: In consequence of these results A1/A2-fractures in the upper thoracic spine (15 degrees will be stabilized anteriorly, in other regions functional treated. A3-fractures of thoracic spine and thoracolumbar junction will be operated from anterior, in lower lumbar spine (>L3) from dorsal. B- and C-injuries should be instrumented with a combined dorsoventral procedure.

[Crossed screw osteosynthesis of proximal humerus fractures]. / Die gekreuzte Schraubenosteosynthese proximaler Humerusfrakturen.

Between March 1997 and October 1999 thirty-one patients with displaced proximal humeral fractures were treated with crossed screw osteosynthesis. Insertion of the screws was realized by using a deltoideo-pectoral approach placing the screws anteriorly and posteriorly in a crossed manner from the distal fragment into the humeral head. Additionally, in all two-part-fractures a tension band was applied. In all three-part-fractures, the greater tuberosity was reattached by additional screws. In 21 patients (14 female, 7 male, median age 62 years, 18-86) a clinical and radiological follow-up (median 18 months, 10-29) was obtained. Fractures were classified as two-part-fractures in 10 patients and as three-part-fractures in 11 patients. According to the Constant-Score, "excellent" and "good" results were achieved in 15 patients, "moderate" results were found in 3 patients. However, in 3 patients results were only "poor" (1 two-part-, 2 three-part-fractures). The complication rate was 29% (premature hardware removal due to head perforation in 3 cases; humeral head necrosis necessitating prosthetic replacement in 2 patients; secondary displacement in 1 case). Crossed screw osteosynthesis represents an justified alternative in the surgical treatment of displaced proximal humeral fractures permitting early functional therapy.