Søren Ohrt-Nissen

Dr. Søren Ohrt-Nissen

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Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 November 2016 in Spine
Verified
Journal Article
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SOSøren Ohrt-Nissen
Søren Ohrt-Nissen
DHDennis W. Hallager
Dennis W. Hallager
MGMartin Gehrchen
Martin Gehrchen
BDBenny Dahl
Benny Dahl
Retrospective cohort study. Objective. To determine treatment outcome with providence brace (PB) and to assess the ability of pretreatment supine lateral bending radiographs (SLBR) in predicting curve progression. Results from treatment with the PB for adolescent idiopathic ccoliosis (AIS) have been inconsistent and further research is needed. The association between flexibility, as determined by pretreatment SLBR, and curve progression has not previously been examined. All patients treated with the PB from 2006 to 2011 who met Scoliosis Research Society (SRS) bracing criteria were included. Flexibility of the curve was determined based on SLBR and radiographic variables were registered at beginning of treatment and at skeletal maturity (SM) or before surgery. An increase in standing Cobb angle by more than 5 degrees was considered progression. Follow-up SRS-22 scores were compared with a control group with minor AIS. Analysis included multiple linear and logistic regression. A total of 63 patients were included. Mean age was 13.3 years (SD: 1.5) and mean standing Cobb angle was 34° (SD: 5°). Radiographic progression was observed in 43% of patients at SM and surgical rate was 27% and 37% at SM and 2-year follow up, respectively. SRS-22 total scores were similar but the mental health score was significantly better in the control group (P = 0.042). Multiple linear regression analysis showed that decreased flexibility adjusted for age, Cobb angle, and menarchal status was significantly associated with curve progression (P < 0.001). Multiple logistic regression analysis showed that a one percent increase in flexibility was associated with a decrease in risk of curve progression ≥6° (odds ratio = 0.95; 95% confidence interval 0.90–0.98; P = 0.013). Progression was seen in 43% of AIS patients treated with the PB. Increase in flexibility was independently associated with a decreased risk of progression. Level of Evidence: 3

20 September 2022 in Acta Orthopaedica
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Journal Article
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SBStig Brorson
Stig Brorson
BVBjarke Viberg
Bjarke Viberg
PGPer Gundtoft
Per Gundtoft
BJBamo Jalal
Bamo Jalal
SOSøren Ohrt-Nissen
Søren Ohrt-Nissen
Background and purpose: Proximal humeral fractures (PHF) can be managed surgically or non-surgically. Locking plates have been the preferred head-preserving surgical technique while hemiarthroplasty (HA) or reverse shoulder arthroplasty (RSA) have been used in joint replacement surgery. We describe the epidemiology and trends in management of acute PHF in Denmark with a focus on (i) changes in the incidence of PHF; (ii) changes in the proportion of surgical cases; and (iii) changes in preferred surgical techniques.Patients and methods: Data on diagnoses and interventions was retrieved from the Danish National Patient Register. Patients aged 18 years and above were included. Surgical treatment was defined as the diagnosis of PHF combined with a predefined surgical procedure code within 3 weeks of injury. Data on plate osteosynthesis, HA, RSA, and “other techniques” was retrieved. Non-surgical treatment was defined as no relevant surgical procedure code within 3 weeks.Results: We identified 137,436 PHF (72% women) in the Danish National Patient Register. The overall mean incidence was 138/100,000/year (500 for women 60 years or above). Non-surgical treatment accounted for 119,966 (87%). The 17,470 surgical procedures included 42% locking plates, 34% arthroplasties, and 25% other techniques. The rate of surgery declined from 17% in 2013 to 11% in 2018.Interpretation: The overall incidence of PHF remained stable between 1996 and 2018 but the absolute number increased. The approach to PHF remains predominantly non-surgical. The number of surgeries in Denmark have decreased since 2013, especially for locking plates and HA, while RSA is increasingly used.

30 June 2018 in Neurospine
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Journal Article
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SOSøren Ohrt-Nissen
Søren Ohrt-Nissen
BDBenny Dahl
Benny Dahl
MGMartin Gehrchen
Martin Gehrchen
The surgical treatment of adolescent idiopathic scoliosis (AIS) involves 3-dimensional curve correction with multisegmental pedicle screws attached to contoured bilateral rods. The substantial corrective forces exert a high level of stress on the rods, and the ability of the rod to withstand these forces without undergoing permanent deformation relies on its biomechanical properties. These properties, in turn, are dependent on the material, diameter, and shape of the rod. The surgical treatment of AIS is characterized by the requirement for a special biomechanical profile that may differ substantially from what is needed for adult deformity surgery. This overview summarizes the current knowledge of rod biomechanics in frequently used rod constructs, with a particular focus on translational research between biomechanical studies and clinical applicability in AIS patients.


1 November 2017 in Spine
Verified
Journal Article
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GYGuanfeng Yao
Guanfeng Yao
Jason Pui Yin CheungJason Pui Yin Cheung
Jason Pui Yin Cheung
HSHideki Shigematsu
Hideki Shigematsu
SOSøren Ohrt-Nissen
Søren Ohrt-Nissen
KCKenneth Cheung
Kenneth Cheung
DSDino Samartzis
Dino Samartzis
A prospective radiographic analysis of adolescent idiopathic scoliosis (AIS) patients managed with alternate-level pedicle screw fixation was performed. The objective of this study was to characterize segmental curve flexibility and to determine its predictive value in curve correction in AIS patients. Little is known regarding the distinct segmental curve characteristics and their ability to predict curve correction in patients with AIS. The segmental Cobb angle was measured on posteroanterior standing radiographs and on fulcrum bending radiographs. Radiographs were analyzed preoperatively and at 2 years postoperatively and the curve was divided into upper, mid, and lower segments based on predefined criteria. The segmental flexibility and the segmental fulcrum bending correction index (FBCI) were calculated. Eighty patients were included with mean age of 15 years. Preoperative mean segmental Cobb angles were 18, 31, and 17 degrees in the upper, mid, and lower segments, respectively. Segmental bending Cobb angles were 6, 13, and 4 degrees, respectively, corresponding to segmental flexibilities of 50%, 47%, and 83% in the upper, mid, and lower segments, respectively (P < 0.001). At 2-year follow up, the mean segmental FBCI were 155%, 131%, and 100% in the upper, mid, and lower segments, respectively (P < 0.001), which suggested that the lower segment of the curve was more flexible than the other segments and that higher correction was noted in the upper segments. A significant, positive correlation was noted between the segmental bending Cobb angle and the segmental FBCI (P < 0.05), whereby the strength of the correlation varied based on the curve segment. This is the first study to demonstrate the segmental variations in curve flexibility using the fulcrum bending radiograph in AIS patients. Curve flexibility is not uniform throughout the curve and different segments exhibit greater flexibility/correctibility than others. Segmental flexibility should be considered in assessing AIS patients and in the clinical decision-making strategy to optimize curve correction outcomes. Level of Evidence: 03

14 October 2010 in Emergency Medicine Journal
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Journal Article
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SOSøren Ohrt-Nissen
Søren Ohrt-Nissen
LFLennart Friis-Hansen
Lennart Friis-Hansen
BDBenny Dahl
Benny Dahl
JSJakob Stensballe
Jakob Stensballe
BRBertil Romner
Bertil Romner
LRLars S Rasmussen
Lars S Rasmussen
Background Protein S100B has proven to be a useful biomarker for cerebral damage. The predictive ability of S100B may, however, be affected by extracerebral injuries. The aim of this study was to investigate serum levels of S100B in patients with either isolated head injury (IHI), multi trauma with head injury (MTHI), or no head injury (NHI). The primary aim was to assess if a significant difference in serum levels of S100B could be found between IHI and MTHI patients. Methods Patients (233) were primarily admitted to the trauma centre. Serum samples were drawn on admission and 6 h after trauma and then stored at −80°C until analysed. Variables included Abbreviated Injury Scale (AIS) for head trauma, Injury Severity Score (ISS) and 30-day survival. Results Two patients could not be classified. IHI occurred in 28, MTHI in 102 and NHI was found in 101. The median S100B concentrations on arrival were 0.47, 1.68 and 0.49 μg/l, respectively (p<0.0001). The corresponding values at 6 h were 0.14, 0.31 and 0.15 μg/l, respectively (p<0.0001). S100B was significantly higher in patients with MTHI than in patients with IHI at both time points (p values 0.0005 and 0.01). There was no significant difference in S100B between patients having IHI and patients with NHI (p=0.81 and p=0.67). Conclusions High serum levels of S100B were found early after trauma. The highest concentrations of S100B were found in patients with multi trauma. This suggests that S100B serum concentrations are significantly affected by extracerebral injuries.