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]

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]

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.

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]

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.

[Differentiated therapy in necrotizing fasciitis of three extremities]

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]

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 (<Th10) with kyphosis >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.

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.

[Crossed screw osteosynthesis of proximal humerus fractures]

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.