Utilization of Spinal Navigation to Facilitate Hassle-Free Rod Placement during Minimally-Invasive Long-Construct Posterior Instrumentation

Arun-Kumar Kaliya-Perumal,Worawat Limthongkul,Jacob Yoong-Leong Oh 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.3

During minimally-invasive long-construct posterior instrumentation, it may be challenging to contour and place the rod as the screw heads are not visualized. To overcome this, we utilized the image data merging (IDM) facility of our spinal navigation system to visualize a coherent whole image of the construct throughout the procedure. Here, we describe this technique that was used for a patient in whom L1–L5 posterior instrumentation was performed. Using an IDM facility, screws are color coded and after placement, the final image is saved. Saved images of all previous screws are displayed and observed while placing the subsequent screws. Therefore, the entry point, depth, and mediolateral alignment of subsequent screws can be adjusted to fall in line with previous screws such that the rod can be placed without hassle. Moreover, final adjustments to the construct are kept to a minimum. The possibility of screw pullout due to force engaging the rod on poorly aligned screws is thus avoided.

Spinal Navigation during Orthopedic Residency Training: A Double-Edged Sword?

Arun-Kumar Kaliya-Perumal,Tamara Soh,Mark Tan,Colum Patrick Nolan,Chun Sing Yu,Jacob Yoong-Leong Oh 대한정형외과학회 2019 Clinics in Orthopedic Surgery Vol.11 No.2

Background: Orthopedic residents in our institute have the opportunity to participate in navigation-assisted spine surgery during their residency training. This paves the way for a new dimension of learning spine surgery, which the previous generation was not exposed to. To study this in detail, we conducted a cross-sectional descriptive survey among our residents to analyse their perception, understanding, and competency regarding pedicle screw application using spinal navigation. Methods: We selected orthopedic residents (n = 20) who had completed 3 years of training that included at least one rotation (4–6 months) in our spine division. They were asked to respond to a four-part questionnaire that included general and Likert scale-based questions. The first two parts dealt with various parameters regarding spinal navigation and free-hand technique for applying pedicle screws. The third part dealt with residents’ opinion regarding the advantages and disadvantages of spinal navigation. The final part was an objective analysis of residents’ ability to identify the pedicle screw entry points in selected segments. Results: We found that our residents were better trained to apply pedicle screws using spinal navigation. The mean Likert scale score for perception regarding their competency to apply pedicle screws using spinal navigation was 3.65 ± 0.81, compared to only 2.8 ± 0.77 when using the free-hand technique. All residents agreed that spinal navigation is an excellent teaching tool with higher accuracy and greater utility in anatomically critical cases. However, 35% of the residents were not able to identify the entry points correctly in the given segments. Conclusions: All selected residents were perceived to be competent to apply pedicle screws using spinal navigation. However, some of them were not able to identify the entry points correctly, probably due to overreliance on spinal navigation. Therefore, we encourage residents to concentrate on surface anatomy and tactile feedback rather than completely relying on the navigation display monitor during every screw placement. In addition, incorporating cadaveric and saw bone workshops as a part of teaching program can enhance better understanding of surgical anatomy.

Revalidating Pfirrmann’s Magnetic Resonance Image-Based Grading of Lumbar Nerve Root Compromise by Calculating Reliability among Orthopaedic Residents

Arun-Kumar Kaliya-Perumal,Senthil-Kumar Ariputhiran-Tamilselvam,Chi-An Luo,Sivaharivelan Thiagarajan,Udhayakumar Selvam,Raj-Prabhakar Sumathi-Edirolimanian 대한정형외과학회 2018 Clinics in Orthopedic Surgery Vol.10 No.2

Background: Intervertebral disc herniations lead to subsequent compromise of the nerve root. The root can either have a mere contact with the disc material or be pushed aside or compressed. This was earlier graded by Pfirrmann and colleagues. We intend to revalidate this grading system by performing a reliability analysis among orthopaedic residents. Methods: Fifty axial cut magnetic resonance (MR) images of the affected lumbar disc level that belonged to different patients (age, 37.8 ± 10.4 years; 33 males and 17 females) were chosen and given to five orthopaedic residents for grading according to the Pfirrmann’s MR image-based grading of lumbar nerve root compromise. Responses were received in the form of categorical variables and reliability was assessed. Results: On doing percentage statistics, we found that 14 images had 100% agreement, 22 had 80% agreement and 14 had 60% agreement. We inferred an overall agreement of 80% ± 15.1%. In addition, interrater reliability was determined by calculating the Fleiss’ kappa, which was found to be 0.521, signifying moderate agreement. Intrarater reliability was determined by calculating Cohen’s kappa, which was found to be 0.696, signifying substantial agreement. Conclusions: Our residents took only a short time to learn and reproduce this grading system as ratings that proved to be moderately reliable. Even though the value of kappa was slightly lower, reliability was similar to that of the original authors. We think that this grading system can be adopted in day-to-day practice by framing appropriate rules to interpret MR images where the nerve roots are not visible.

Spontaneous Total Resolution of Severe Lumbar Disc Herniation

Arun-Kumar Kaliya-Perumal,Jacob Yoong-Leong Oh 전남대학교 의과학연구소 2020 전남의대학술지 Vol.56 No.1

Early Postoperative Loss of Disc Height Following Transforaminal and Lateral Lumbar Interbody Fusion: A Radiographic Analysis

Kaliya-Perumal Arun-Kumar,Soh Tamara Lee Ting,Tan Mark,Oh Jacob Yoong-Leong 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.4

Study Design: Retrospective comparative radiological study. Purpose: To analyze the difference in early disc height loss following transforaminal and lateral lumbar interbody fusion (TLIF and LLIF). Overview of Literature: Minimal disc height loss facilitated by the polyaxial screw heads can occur naturally due to mechanical loading following lumbar fusion procedures. This loss does not usually cause any significant foraminal narrowing. However, when there is concomitant cage subsidence, symptomatic foraminal compromise could occur, especially when posterior decompression is not performed. It is not known whether the type of procedure, TLIF or LLIF, could influence this phenomenon. Methods: Retrospectively, patients who underwent TLIF and LLIF for various degenerative conditions were shortlisted. Each of their fused levels with the cage in situ was analyzed independently, and the preoperative, postoperative, and follow-up disc height measurements were compared between the groups. In addition, the total disc height loss since surgery was calculated at final follow-up and was compared between the groups. Results: Forty-six patients (age, 64.1±8.9 years) with 70 cage levels, 35 in each group, were selected. Age, sex, construct length, preoperative disc height, cage height, and immediate postoperative disc height were similar between the groups. By 3 months, disc height of the TLIF group was significantly less and continued to decrease over time, unlike in the LLIF group. By 1 year, the TLIF group demonstrated greater disc height loss (2.30±1.3 mm) than the LLIF group (0.89±1.1 mm). However, none of the patients in either group had any symptomatic complications throughout follow-up. Conclusions: Although our study highlights the biomechanical advantage of LLIF over TLIF in maintaining disc height, none of the patients in our cohort had symptomatic complications or implant-related failures. Hence, TLIF, as it incorporates posterior decompression, remains a safe and reliable technique despite the potential for greater disc height loss.

Factors Influencing Early Disc Height Loss Following Lateral Lumbar Interbody Fusion

Kaliya-Perumal Arun-Kumar,Soh Tamara Lee Ting,Tan Mark,Oh Jacob Yoong-Leong 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.5

Study Design: Retrospective radiological analysis.Purpose: To analyze the factors influencing early disc height loss following lateral lumbar interbody fusion (LLIF).Overview of Literature: Postoperative disc height loss can occur naturally as a result of mechanical loading. This phenomenon is enabled by the yielding of the polyaxial screw heads and settling of the cage to the endplates. When coupled with cage subsidence, there can be significant reduction in the foraminal space which ultimately compromises the indirect decompression achieved by LLIF.Methods: Seventy-two cage levels in 37 patients aged 62±10.2 years who underwent single or multilevel LLIF for degenerative spinal conditions were selected. Their preoperative and postoperative follow-up radiographs were used to measure the anterior disc height (ADH), posterior disc height (PDH), mean disc height (MDH), disc space angle (DSA), and segmental angle. Correlations between the loss of disc height and several factors, including age, construct length, preoperative lordosis, postoperative lordosis, disc height, cage dimensions, and cage position, were analyzed.Results: We found that the lateral interbody cages significantly increased ADH, PDH, MDH, and DSA after surgery (p <0.0001). However, there was a loss of disc height over time. All postoperative disc height parameters, especially the amount of increase in MDH (r =0.413, p <0.0001) after surgery, showed a significant positive association with early disc height loss. The levels demonstrating a significant (≥25%) height loss were those that exhibited a substantial height increase (128.3%, 4.6±3.0 to 10.5±5.6 mm) postoperatively. However, the levels that showed less than 25% height loss were those that exhibited, on average, only a 57.4% height increase post-operatively.Conclusions: The greater the postoperative increase in disc height, the greater the disc height loss throughout early follow-up. Therefore, achieving an optimal disc height rather than overcorrection is an important surgical strategy to adopt when performing LLIF.

A Novel Scale for Assessing the Burden of Caregiving for Functionally Compromised Patients: Proposal and Validation

Arun-Kumar Kaliya-Perumal,Anupama Korlakunta,Jacquilyne Kharlukhi,Sarada Devireddy 대한가정의학회 2021 Korean Journal of Family Medicine Vol.42 No.1

Background: Disability not only burdens the patient, but also the caregiver. To quantify this caregiving burden, we propose a simple four-part questionnaire tool. Our objective is to validate this questionnaire by administering it to caregivers who oversee patients with low back pain and are functionally compromised. Methods: Twenty-five spouse caregivers who were taking care of in-patients awaiting surgery for various lumbar spine pathologies were shortlisted. The content-validated questionnaire was administered on different occasions during the care recipient’s treatment. Cronbach’s α was calculated to assess internal consistency. Interrelationships between the care recipient’s pain score, extent of functional compromise, and caregiver burden were calculated. The questionnaire’s ability to track changes in the caregivers’ attitudes over time was assessed. Results: The percentage of caregiver burden before the surgery of the care recipient was 52.5. This increased significantly to 61.1% (P=0.001) 3 days after surgery, but was found to decrease to 32.5% (P<0.001) a month after the surgery; demonstrating the questionnaire’s efficacy to track changes. Cronbach’s alpha of 0.948 signifies the questionnaire’s excellent internal consistency. Pearson’s correlation coefficient (r) between the care recipient’s pain score and caregiver’s burden score was 0.41 (P=0.04), and between the care recipient’s disability score and caregiver’s burden score was 0.9 (P<0.001). Conclusion: The proposed questionnaire is consistent and can track changes in a caregiver’s attitude over time. It can be adopted for clinical use to assess the burden of caregiving for functionally compromised patients.

Assessment of Anteroposterior Subpedicular Approach and Oblique Scotty Dog Subpedicular Approach for Selective Nerve Root Block

Arun-Kumar Kaliya-Perumal,Yu-Cheng Yeh,Chi-An Luo,Kit-Yang Joey-Tan 대한정형외과학회 2017 Clinics in Orthopedic Surgery Vol.9 No.1

Background: The technique used to administer a selective nerve root block (SNRB) varies depending on individual expertise. Both the anteroposterior (AP) subpedicular approach and oblique Scotty dog subpedicular approach are widely practiced. However, the literature does not provide a clear consensus regarding which approach is more suitable. Hence, we decided to analyse the procedural parameters and clinical outcomes following SNRBs using these two approaches. Methods: Patients diagnosed with a single lumbar herniated intervertebral disc (HIVD) refractory to conservative management but not willing for immediate surgery were selected for a prospective nonrandomized comparative study. An SNRB was administered as a therapeutic alternative using the AP subpedicular approach in one group (n = 25; mean age, 45 ± 5.4 years) and the oblique Scotty dog subpedicular approach in the other group (n = 22; mean age, 43.8 ± 4.7 years). Results were compared in terms of the duration of the procedure, the number of C-arm exposures, accuracy, pain relief, functional outcome and the duration of relief. Results: Our results suggest that the oblique Scotty dog subpedicular approach took a significantly longer duration (p = 0.02) and a greater number of C-arm exposures (p = 0.001). But, its accuracy of needle placement was 95.5% compared to only 72% using the AP subpedicular approach (p = 0.03). There was no significant difference in terms of clinical outcomes between these approaches. Conclusions: The AP subpedicular approach was simple and facile, but the oblique Scotty dog subpedicular approach was more accurate. However, a brief window period of pain relief was achieved irrespective of the approaching technique used.

Neuromonitoring in Cervical Spine Surgery: When Is a Signal Drop Clinically Significant?

Decruz Joshua,Kaliya-Perumal Arun-Kumar,Wong Kevin Ho-Yin,Kumar Dinesh Shree,Yang Eugene Weiren,Oh Jacob Yoong-Leong 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.3

Study Design: Retrospective cohort study. Purpose: To identify the clinical significance of different patterns of intraoperative neuromonitoring (IONM) signal alerts. Overview of Literature: IONM is a long-established valuable adjunct to complex spine surgeries. IONM for cervical spine surgery is in the form of somatosensory evoked potential (SSEP) and motor evoked potential (MEP). The efficacy of both modalities (individually or in combination) to detect clinically significant neurological compromise is constantly being debated and requires conclusive suggestions. Methods: Clinical and neuromonitoring data of 207 consecutive adult patients who underwent cervical spine surgeries at multiple surgical centers using bimodal IONM were analyzed. Signal changes were divided into three groups. Group 0 had transient signal changes in either MEPs or SSEPs, group 1 had sustained unimodal changes, and group 2 had sustained changes in both MEPs and SSEPs. The incidences of true neurological deficits in each group were recorded. Results: A total of 25% (52/207) had IONM signal alerts. Out of these signal drops, 96% (50/52) were considered to be false positives. Groups 0 and 1 had no incidence of neurological deficits, while group 2 had a 29% (2/7) rate of true neurological deficits. The sensitivities of both MEP and SSEP were 100%. SSEP had a specificity of 96.6%, while MEP had a lower specificity at 76.6%. C5 palsy rate was 6%, and there was no correlation with IONM signal alerts (p=0.73). Conclusions: This study shows that we can better predict its clinical significance by dividing IONM signal drops into three groups. A sustained, bimodal (MEP and SSEP) signal drop had the highest risk of true neurological deficits and warrants a high level of caution. There were no clear risk factors for false-positive alerts but there was a trend toward patients with cervical myelopathy.

Is Spinal Surgery Safe for Elderly Patients Aged 80 and Above? Predictors of Mortality and Morbidity in an Asian Population

Joshua Yuan-Wang Tan,Arun-Kumar Kaliya-Perumal,Jacob Yoong-Leong Oh 대한척추신경외과학회 2019 Neurospine Vol.16 No.4

Objective: We aimed to determine the 2-year mortality and morbidity rates following spine surgery in elderly patients (age ≥80 years) and to study the associated risk factors. Methods: The records of patients ≥80 years of age who underwent spine surgery during the years 2003–2015 at Tan Tock Seng Hospital, Singapore were retrospectively reviewed. Information was collected on their demographic characteristics, comorbidities, diagnosis, general and neurological status, type of surgery, and outcomes. The mortality and morbidity rates over a 2-year period were analyzed. Bivariate analyses were carried out to identify factors associated with mortality. Results: We selected 47 patients (mean age, 83.3 years; range, 80–91 years) who were followed up for a mean duration of 27.7 months. The mortality rates at 30 days, 6 months, 1 year, and 2 years following surgery were 2.1%, 8.5%, 10.6%, and 12.8%, respectively. The factors significantly associated with mortality included multiple comorbidities, nondegenerative aetiology, and vertebral fractures. The overall morbidity rate was 48.9%, and 17% of this cohort had major complications. Conclusion: Surgeons should strategize management protocols with due consideration of the mortality and morbidity rates, and be wary of operating on patients with multiple comorbidities, nondegenerative conditions, and vertebral fractures.