Krishnan Sircar

Dr. Krishnan Sircar

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

View All Publications
1 July 2020 in European Spine Journal
Verified
Journal Article
Open access
PDF file
AYAyla Yagdiran
Ayla Yagdiran
COChristina Otto-Lambertz
Christina Otto-Lambertz
KLKristina Michaela Lingscheid
Kristina Michaela Lingscheid
KSKrishnan Sircar
Krishnan Sircar
CSChristina Samel
Christina Samel
JSJan Siewe
Jan Siewe
Purpose: Vertebral osteomyelitis (VO) has a high mortality and leads to chronic pain and functional disability. Surgical treatment is often necessary. To date, little is known about the consequences of surgery on patient outcome. The aim of this study was to determine the quality of life (QoL) and mortality rates of surgically treated VO patients for a period of 2 years. Methods: Patients with VO undergoing surgical treatment in a tertiary referral hospital from 2008 to 2015 were included prospectively. Data were collected before (T0) as well as 1 year (T1) and 2 years (T2) post-surgery. Within the European Spine Tango registry, prospective patient and QoL data were collected using validated outcome scores: Oswestry Disability Index, Short Form 36/EuroQol, Visual Analog Scale, and Core Outcome Measures Index. Results: From 195 patients surgically treated for VO, QoL data were available from 136 patients at T0, 100 patients at T1, and 82 patients at T2, respectively. The 1- and 2-year mortality rates were 20% and 23%. Mainly all QoL outcome scores showed significant improvement at T1 and did not change significantly from T1 to T2. Conclusion: Surgical treatment of VO patients leads to significantly improved QoL. Nevertheless, QoL levels were below those of the general population. Our results underscore that spine disability questionnaires measuring QoL are mandatory to demonstrate comprehensively the severity of this entity. Our study confirms a high mortality and points out the role of VO as a potentially life-threatening condition.

29 December 2023 in Journal of Bone and Joint Surgery
Verified
Journal Article
Closed access
NKNikolaus Kernich
Nikolaus Kernich
KSKrishnan Sircar
Krishnan Sircar
DJDorothee Jochimsen
Dorothee Jochimsen
SWSebastian Walter
Sebastian Walter
PEPeer Eysel
Peer Eysel
CWCarolyn Weber
Carolyn Weber
Background: The aim of this study was to determine differences between patients who underwent surgical treatment and those who underwent nonsurgical treatment of vertebral osteomyelitis (VO) and to identify potential factors influencing treatment failure (death and/or recurrence within 1 year). Methods: We performed a retrospective analysis of clinical data prospectively collected from patients treated for VO between 2008 and 2020. The decision between surgical and nonsurgical treatment was made for each patient based on defined criteria. A 1:1 propensity score matching was performed to exclude confounders between the 2 treatments. Univariate and multivariable analyses were performed to identify potential risk factors for death and/or recurrence within the first year after VO diagnosis. Results: Forty-two patients (11.8%) were treated nonsurgically and 313 patients (88.2%) underwent surgery. A higher percentage of the surgically treated patients than the nonsurgically treated patients had an American Society of Anesthesiologists score of >2 (69.0% versus 47.5%; p = 0.007), and the thoracic spine was affected more often in the surgical group (30.4% versus 11.9%; p = 0.013). Endocarditis was detected significantly more often in the nonsurgically treated patients (14.3% versus 4.2%; p = 0.018). The recurrence rate was 3 times higher in the nonsurgically treated patients (16.7% versus 5.4%; p = 0.017), but this difference was no longer detectable after propensity matching. After matching, the nonsurgically treated patients showed an almost 7-fold higher 1-year mortality rate (25.0% versus 3.7%; p = 0.018) and an almost 3-fold higher rate of treatment failure (42.9% versus 14.8%; p = 0.022). Multivariable analysis revealed nonsurgical treatment and bacteremia to be independent risk factors for treatment failure. Conclusions: In our matched cohort of patients with VO, surgical intervention resulted in a significantly lower rate of treatment failure (death and/or recurrence within 1 year) compared with nonsurgical intervention. Furthermore, nonsurgical treatment was an independent risk factor for treatment failure. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.


7 August 2023 in Global Spine Journal
Verified
Journal Article
Open access
KSKrishnan Sircar
Krishnan Sircar
NJNorma Jung
Norma Jung
NKNikolaus Kernich
Nikolaus Kernich
KZKourosh Zarghooni
Kourosh Zarghooni
PEPeer Eysel
Peer Eysel
CHChristian Herren
Christian Herren
Study Design: retrospective study. Objectives: In addition to surgical treatment of spinal epidural abscesses (SEA), a conservative, medical treatment for patients without acute neurologic deficits has been proposed. However, the risk factors for neurologic deficits are unclear. This study aims to identify factors predisposing patients with SEA to neurological impairment. Methods: All patients treated for SEA between 2008 and 2021 were identified from a prospective vertebral-osteomyelitis registry of a tertiary referral centre. Patient demographics, comorbidities, pathogens, degree of osseous destruction, location of SEA and preoperative neurologic status were retrospectively collected. Differences between patients with (Group 1) and without (Group 2) pretreatment neurologic deficits were assessed by univariate and logistic regression analysis. Results: A total of 140 patients with SEA were included. Forty-three patients (31%) had a neurologic deficit and 97 patients (69%) had no neurologic deficit prior to therapy. The prevalence of diabetes mellitus (35% vs 19%, P = .03), median visual analogue scale leg pain (8 vs 5, P = .01), median American Society of Anesthesiologists (ASA) Score (3 vs 2.6, P = .003) and mean Body-Mass-Index (29 vs 26, P = .02) differed between Group 1 and 2 in univariate analysis. In multivariable analysis, diabetes mellitus (odds ratio = 2.7), female sex (odds ratio = 2.5) and ASA-Score (odds ratio = 2.4) were significant contributors for neurologic deficits. Conclusions: In patients with a SEA without neurologic deficits, the ASA score and diabetes mellitus should be considered, especially in female patients. These patients may be at a higher risk for developing a neurologic deficit and may benefit from an early surgical treatment.

3 January 2023 in Acta Orthopaedica et Traumatologica Turcica
Verified
Journal Article
Open access
AYAyla Yagdiran
Ayla Yagdiran
KSKrishnan Sircar
Krishnan Sircar
NJNorma Jung
Norma Jung
PEPeer Eysel
Peer Eysel
JBJan Bredow
Jan Bredow
FBFrank Beyer
Frank Beyer
Objective: This study aimed to determine threshold values of validated quality of life (QoL) scores, including Oswestry Disability Index (ODI) and Core Outcome Measures Index (COMI), for predicting a successful outcome following surgical treatment of lumbar spondylodiscitis (LS). Methods: Patients with lumbar spondylodiscitis (LS) undergoing surgery in a tertiary referral hospital were included prospectively from 2008-2019. Data were collected both before surgery (T0) and one year after surgery (T1). QoL was measured using ODI and COMI. The successful clinical outcome was defined by the combination of the following four criteria: no recurrence of spondylodiscitis, back pain ≤4 on visual analogue scale or relief of ≥3 points, absence of LS-related neurological deficit, and radiological fusion of the affected segment. For subgroup analysis, group 1 consisted of patients with a favorable treatment outcome (meeting all four criteria), while group 2 included patients with unfavorable treatment outcome (meeting ≤3 criteria). Results: Ninety-two LS patients (median age = 66 years; age range = 57-74) were analyzed. QoL scores improved significantly. Threshold values for the ODI and COMI were calculated at 35 and 4.2 points, respectively. The area under curve for the ODI was 0.856 (95%-CI 0.767- 0.945; P<0.001) and 0.839 (95% CI-0.749-0.928; P<0.001) for the COMI score. Eighty percent of patients achieved a favorable outcome. Conclusion: Objective measurement and evaluation of successful surgical treatment of spondylodiscitis require defined thresholds of quality of life scores. We were able to define such thresholds for Oswestry Disability Index and Core Outcome Measures Index. These can be useful to assess clinically relevant changes and therefore allow a more precise estimation of the post-surgical outcome. Level of Evidence: Level II, Prognostic study. Cite this article as: Yagdiran A, Sircar K, Jung N, Eysel P, Bredow J, Beyer F. Determining threshold values for success after surgical treatment of lumbar spondylodiscitis using quality of life scores. Acta Orthop Traumatol Turc., 2023;57(3):99-103.

9 April 2024 in Clinical Biomechanics
Verified
Journal Article
Open access
KSKrishnan Sircar
Krishnan Sircar
MWMaximilian Weber
Maximilian Weber
SWSebastian G. Walter
Sebastian G. Walter
NONadine Ott
Nadine Ott
APAndreas Prescher
Andreas Prescher
NKNikolaus Kernich
Nikolaus Kernich
The application of expandable titanium-cages has gained widespread use in vertebral body replacement for indications such as burst fractures, tumors and infectious destruction. However, torque forces necessary for a satisfactory expansion of these implants and for subsidence of them into the adjacent vertebrae are unknown within the osteoporotic spine. Six fresh-frozen human, osteoporotic, lumbar spines were dorsally instrumented with titanium implants (L2-L4) and a partial corpectomy of L3 was performed. An expandable titanium-cage was inserted ventrally and expanded by both residents and senior surgeons until fixation was deemed sufficient, based on haptic feedback. Torque forces for expansion were measured in Nm. Expansion was then continued until cage subsidence occurred. Torque forces necessary for subsidence were recorded. Strain of the dorsal rods during expansion was measured with strain gauges. The mean torque force for fixation of cages was 1.17 Nm (0.9 Nm for residents, 1.4 Nm for senior surgeons, p = .06). The mean torque force for subsidence of cages was 3.1 Nm (p = .005). Mean peak strain of the dorsal rods was 970 μm/m during expansion and 1792 μm/m at subsidence of cages (p = .004). The use of expandable titanium-cages for vertebral body replacement seems to be a primarily safe procedure even within the osteoporotic spine as torque forces required for subsidence of cages are nearly three times higher than those needed for fixation. Most of the expansion load is absorbed by straining of the dorsal instrumentation. Rod materials other than titanium may alter the torque forces found in this study.