Gregor Schmeiser’s research while affiliated with Schön Klinik Hamburg and other places

Introduction Percutaneous cervical pedicle screw placement is challenging due to complex anatomy, and requires navigation support. It is unclear how to ensure navigation accuracy in minimally invasive procedures. Research question How accurate is image-guided percutaneous pedicle screw positioning after referencing with only one clamp for the complete subaxial cervical spine? Materials and methods In six cadavers, all subaxial cervical pedicles were fitted with screws using a standardized procedure. Briefly, a reference clamp was placed via a small skin incision on spinous process C7. The procedure started from C3 and progressed towards C7, without additional imaging, using one registration for all vertebrae. Screws were placed using a navigated screwdriver. Cone-beam CT was performed at three time-points. Screw position was directly intraoperatively evaluated by the surgeons using a modified classification—from Grade 1 (perfect placement) to Grade 5 (highly inaccurate)—and these data were re-evaluated by two independent radiologists. Results In six human specimens, 10 guidewires each were placed bilaterally in C3–C7. One screw (1.7%) was intraoperatively classified as Grade 3, but as Grade 4 in the second assessment. All other screws were classified as Grades 1–2 (89.8%) or 3 (8.5%). Screw placement accuracy was not significantly impacted by distance to the clamp or side selection. Discussion In percutaneously navigated screw placement with intraoperative imaging, safe screw placement was possible with a reference clamp on C7. Clinical application of this technique has been limited to individual cases. We also propose a new classification for improving screw accuracy and clinical consequences.

Zusammenfassung Ziel dieser Studie war die Entwicklung und klinische Evaluation eines Scores, der bei der Entscheidung für eine konservative oder operative Therapie bei osteoporotischen Beckenfrakturen unterstützen soll. In den Jahren 2018 bis 2020 erfolgte die Entwicklung des OF-Pelvis-Scores im Rahmen von insgesamt 5 Treffen der AG Osteoporotische Frakturen der Sektion Wirbelsäule der DGOU. Der OF-Pelvis-Score als Entscheidungshilfe zwischen konservativer und operativer Therapie wurde im Expertenkonsens nach Analyse zahlreicher geriatrischer Sakrum- und Beckenringfrakturen aus mehreren Kliniken entwickelt. Anschließend erfolgte die retrospektive Evaluation des Scores an konsekutiven Patienten aus 3 Kliniken. Folgende Parameter wurden für die Entscheidung zwischen operativem und konservativem Vorgehen als relevant angesehen und flossen in den Score ein: Frakturmorphologie anhand der OF-Pelvis-Klassifikation, Schmerzsituation, Mobilisation, frakturbedingte neurologische Defizite, Gesundheitszustand sowie die Modifier, die bereits in die OF-Pelvis-Klassifikation integriert sind. Bei einem Punktwert < 8 wird eine konservative Therapie empfohlen, bei einem Punktwert > 8 eine operative und bei einem Punktwert von 8 besteht eine relative Operationsindikation. Der OF-Pelvis-Score wurde dann bei insgesamt 107 Patienten retrospektiv nach Aktenlage berechnet. Der OF-Pelvis-Score betrug 8 Punkte bei 4 Patienten (3,7%), die alle operativ versorgt wurden. Von den restlichen 103 Patienten wurden 93 Score-konform therapiert (90,3%). Dabei lehnten 4 der nicht Score-konform versorgten Patienten die empfohlene Operation ab, sodass die tatsächliche Therapieempfehlung in 94,2% Score-konform war. Der OF-Pelvis-Score basiert auf der Frakturmorphologie und klinischen Parametern und ermöglicht die Ableitung einer Therapieempfehlung. Aufgrund der verwendeten klinischen Parameter ist der Score dynamisch und spiegelt die sich ändernde klinische Situation auch im Verlauf wider. In der retrospektiven Evaluation zeigten die OF-Pelvis-Score-basierten Therapieempfehlungen eine sehr hohe Übereinstimmungsrate mit der tatsächlich durchgeführten Therapie.

Study Design Retrospective bicentric Cohort Study. Objective Posterior (PLIF) and transforaminal lumbar interbody fusion (TLIF) have been clinically proven for the surgical treatment of degenerative spinal disorders. Despite many retrospective studies, the superiority of either technique has not been proven to date. In the literature, the complication rate of the conventional PLIF technique is reported to be significantly higher, but with inconsistent complication recording. In this retrospective bicentric study, a less invasive PLIF technique was compared with the conventional TLIF technique and complications were recorded using the validated SAVES V2 classification system. Methods 1142 patients underwent PLIF (702) or TLIF (n = 440) up to 3 levels in two specialized centers. Epidemiological data, intra- and postoperative complications during hospitalization and after discharge were analyzed according to SAVES V2. Results The overall complication rate was 13.74%. TLIF-patients had slightly significant more complications than PLIF-patients (TLIF = 16.6%/PLIF = 11.9%, P = .0338). Accordingly, complications during revision surgeries were more frequent in the first cohort (TLIF = 20.9%/PLIF = 12.6%; P = .03252). In primary interventions, the surgical technique did not correlate with the complication rate (TLIF = 12.4%/PLIF = 11.7%). There were no significant differences regarding severity of complications. Conclusions An important component of this work is the complication recording according to a uniform classification system (SAVES V2). In contrast to previous literature, we could demonstrate that there is not a significant difference between the two surgical techniques.

Zusammenfassung Analog zur Chirurgie an der Brust- und Lendenwirbelsäule, ist es auch an der Halswirbelsäule das Bestreben der minimalinvasiven-Techniken (MIS), hinsichtlich der „target surgery“ vergleichbare Ergebnisse zu den konventionellen Verfahren zu erzielen. Gleichzeitig aber die Vorteile einer weniger traumatisierenden „access surgery“ zu bieten. Im Unterschied zur BWS und LWS, kommen MIS-Techniken an der HWS überwiegend dorsal zum Einsatz. Dies reduziert nicht ihre Bedeutung, da die zervikale Muskulatur sowohl biomechanisch – Halten des Kopfgewichtes – als auch neurophysiologisch – Halten des Sehhorizonts – sehr anspruchsvolle Funktionen erfüllt. Die Notwendigkeit die zugangsbedingte Muskeltraumatisierung operativ zu minimieren ist selbsterklärend. Im Folgenden werden bekannte operative Verfahren in einer „aktualisierten“ Version vorgestellt: Bei der posterioren Foraminotomie führt der transmuskuläre Zugang zu einer Reduktion der Zugangsmorbidität. Die Laminoplastie ist im asiatischen Raum ein etabliertes Verfahren zur Dekompression der multisegmentalen zervikalen Stenose. Die hier vorgestellte unilaterale Variante ist weniger verbreitet, entbehrt aber nicht einer klinischen Begründung. Die Ergänzung mit einer unilateralen Instrumentation erweitert das Indikationsspektrum und wird auch von Kollegen in Fernost beginnend angewendet. Die C1/C2 Instrumentation gewinnt durch die Navigation an „Standardisierung“ und somit an Sicherheit. Die subaxiale Navigation begleitet den Wandel von dem offenen zum perkutanen Einbringen von Pedikelschrauben. Die erwähnten operativen Verfahren unterscheiden sich hinsichtlich Indikation, technischer Durchführung und Akzeptanz. Eines ist ihnen gemeinsam: Die größtmögliche operative Sicherheit mit dem Erhalt die Physiologie der Nackenmuskulatur zu vereinbaren.

Study Design Multicenter prospective cohort study. Objectives Anxiety in combination with osteoporotic vertebral compression fractures (OVCFs) of the spine remains understudied. The purpose of this study was to analyze whether anxiety has an impact on the short-term functional outcome of patients with an OVCF. Furthermore, a direct impact of the fracture on the patient’s anxiety during hospitalization should be recognized. Methods All inpatients with an OVCF of the thoracolumbar spine from 2017 to 2020 were included. Trauma mechanism, analgetic medication, anti-osteoporotic therapy, timed-up-and-go test (TuG), mobility, Barthel index, Oswestry-Disability Index (ODI) and EQ5D-5L were documented. For statistical analysis, the U test, chi-square independence test, Spearman correlation, General Linear Model for repeated measures, Bonferroni analysis and Wilcoxon test were used. The item anxiety/depression of the EQ5D-5L was analyzed to describe the patients’ anxiousness. Results Data from 518 patients from 17 different hospitals were evaluated. Fracture severity showed a significant correlation (r = .087, P = .0496) with anxiety. During the hospital stay, pain medication ( P < .001), anti-osteoporotic medication ( P < .001), and initiation of surgical therapy ( P < .001) were associated with less anxiety. The anxiety of a patient at discharge was negatively related to the functional outcomes at the individual follow-up: TuG ( P < .001), Barthel index ( P < .001), ODI ( P < .001) and EQ5D-5L ( P < .001). Conclusions Higher anxiety is associated with lower functional outcome after OVCF. The item anxiety/depression of the EQ5D-5L provides an easily accessible, quick and simple tool that can be used to screen for poor outcomes and may also offer the opportunity for a specific anxiety intervention.

Study design: Multicenter prospective cohort study. Objective: The study aims to validate the recently developed OF score for treatment decisions in patients with osteoporotic vertebral compression fractures (OVCF). Methods: This is a prospective multicenter cohort study (EOFTT) in 17 spine centers. All consecutive patients with OVCF were included. The decision for conservative or surgical therapy was made by the treating physician independent of the OF score recommendation. Final decisions were compared to the recommendations given by the OF score. Outcome parameters were complications, Visual Analogue Scale, Oswestry Disability Questionnaire, Timed Up & Go test, EQ-5D 5 L, and Barthel Index. Results: In total, 518 patients (75.3% female, age 75 ± 10) years were included. 344 (66%) patients received surgical treatment. 71% of patients were treated following the score recommendations. For an OF score cut-off value of 6.5, the sensitivity and specificity to predict actual treatment were 60% and 68% (AUC .684, P < .001). During hospitalization overall 76 (14.7%) complications occurred. The mean follow-up rate and time were 92% and 5 ± 3.5 months, respectively. While all patients in the study cohort improved in clinical outcome parameters, the effect size was significantly less in the patients not treated in line with the OF score's recommendation. Eight (3%) patients needed revision surgery. Conclusions: Patients treated according to the OF score's recommendations showed favorable short-term clinical results. Noncompliance with the score resulted in more pain and impaired functional outcome and quality of life. The OF score is a reliable and save tool to aid treatment decision in OVCF.

Study design: Subgroup analysis of a multicenter prospective cohort study. Objective: To analyse surgical strategies applied to osteoporotic thoracolumbar osteoporotic fracture (OF) 5 injuries with anterior or posterior tension band failure and to assess related complications and clinical outcome. Methods: A multicenter prospective cohort study (EOFTT) was conducted at 17 spine centers including 518 consecutive patients who were treated for an osteoporotic vertebral fracture (OVF). For the present study, only patients with OF 5 fractures were analysed. Outcome parameters were complications, Visual Analogue Scale (VAS), Oswestry Disability Questionnaire (ODI), Timed Up & Go test (TUG), EQ-5D 5L, and Barthel Index. Results: In total, 19 patients (78 ± 7 years, 13 female) were analysed. Operative treatment consisted of long-segment posterior instrumentation in 9 cases and short-segment posterior instrumentation in 10 cases. Pedicle screws were augmented in 68 %, augmentation of the fractured vertebra was performed in 42%, and additional anterior reconstruction was done in 21 %. Two patients (11 %) received short-segment posterior instrumentation without either anterior reconstruction or cement-augmentation of the fractured vertebra. No surgical or major complications occurred, but general postoperative complications were observed in 45%. At a follow-up of mean 20 ± 10 weeks (range, 12 to 48 weeks), patients showed significant improvements in all functional outcome parameters. Conclusions: In this analysis of patients with type OF 5 fractures, surgical stabilization was the treatment of choice and lead to significant short-term improvement in terms of functional outcome and quality of life despite a high general complication rate.

Study design: Multicenter prospective cohort study. Objective: To analyse therapeutical strategies applied to osteoporotic thoracolumbar OF 4 injuries, to assess related complications and clinical outcome. Methods: A multicenter prospective cohort study (EOFTT) including 518 consecutive patients who were treated for an Osteoporotic vertebral compression fracture (OVCF). For the present study, only patients with OF 4 fractures were analysed. Outcome parameters were complications, Visual Analogue Scale, Oswestry Disability Questionnaire, Timed Up & Go test, EQ-5D 5L, and Barthel Index after a minimum follow-up of 6 weeks. Results: A total of 152 (29%) patients presented with OF 4 fractures with a mean age of 76 years (range 41-97). The most common treatment was short-segment posterior stabilization (51%; hybrid stabilization in 36%). Mean follow up was 208 days (±131 days), mean ODI was 30 ± 21. Dorsoventral stabilized patients were younger compared to the other groups (P < .001) and had significant better TuG compared to hybrid stabilization (P = .049). The other clinical outcomes did not differ in the therapy strategies (VAS pain: P = 1.000, ODI: P > .602, Barthel: P > .252, EQ-5D 5L index value: P > .610, VAS-EQ-5D 5L: P = 1.000). The inpatient complication rate was 8% after conservative and 16% after surgical treatment. During follow-up period 14% of conservatively treated patients and 3% of surgical treated patients experienced neurological deficits. Conclusions: Conservative therapy of OF 4 injuries seems to be viable option in patients with only moderate symptoms. Hybrid stabilization was the dominant treatment strategy leading to promising clinical short-term results. Stand-alone cement augmentation seems to be a valid alternative in selected cases.

Objective: Anterior stabilization of the spine with a lateral approach to insert a large and broad cage creating a better bearing surface to restore or maintain the lumbar lordosis. Indications: Degenerative scoliosis as well as revision surgery for stenosis of the neuroforamen. Lumbar corpectomies between L2/3 and L4/5 can be approached as well. Contraindications: The segment L5/S1 is not suitable for the transmuscular approach. Relative contraindications are previous retroperitoneal surgery and spondylolisthesis with sliding of more than 50% (> Meyerding 2) SURGICAL TECHNIQUE: We describe the transmuscular retroperitoneal approach to the lumbar segments which is called extreme lateral approach (XLIF). To protect the spinal nerves on the way through the psoas muscle, use of intraoperative triggered neuromonitoring is paramount. Postoperative management: Full mobilization directly after surgery is possible in most cases. Weight bearing should be restricted to 20 kg for 3 months after surgery. Results: The transmuscular approach to the lumbar spine is a good alternative to reach the anterior part of the lumbar spine. Degenerative scoliosis as well as stenosis of the neuroforamen especially in revision surgery are good indications for this technique. Injuries of the spinal nerves range from 0.7 to 15%. Other complications are rare.

Background Anxiety in combination with osteoporotic vertebral compression fractures (OVCFs) of the spine remains understudied. The purpose of this study was to analyze whetheranxiety has an impact on the short-term functional outcome of patients with an OVCF. Furthermore, a direct impact of the fracture on the patient’s anxiety during hospitalization should be recognized. Methods A prospective multicentric study in a German-speaking area was performed. All inpatients with an OVCF of the thoracolumbar spine from 2017 to 2020 were included. Trauma mechanism, analgetic medication, anti-osteoporotic therapy, timed-up-and-go test (TuG), mobility, Barthel index, Oswestry-Disability Index (ODI) and EQ5D-5L were documented. For statistical analysis, the U test, chi-square independence test, Spearman correlation, General Linear Model for repeated measures, Bonferroni analysis and Wilcoxon test were used. The item anxiety/depression of the EQ5D-5L was analyzed to describe the patients’ anxiousness. Results Data from 518 patients from 17 different hospitals were evaluated. Fracture severity showed a significant correlation (r=0.087, p=0.0496) with anxiety. During the hospital stay, pain medication (p<0.001), anti-osteoporotic medication (p<0.001), and initiation of surgical therapy (p<0.001) were associated with less anxiety. The anxiety of a patient at discharge was negatively related to the functional outcomes at the individual follow-up: TuG (p<0.001), Barthel index (p<0.001), ODI (p<0.001) and EQ5D-5L (p<0.001). Conclusions Higher anxiety is associated with lower functional outcome after OVCF. The item anxiety/depression of the EQ5D-5L provides an easily accessible, quick and simple tool that can be used to screen for poor outcomes and may also offer the opportunity for a specific anxiety intervention.