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.

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.

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.

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.

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.

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.

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.
Head ; Humans ; Minimally Invasive Surgical Procedures ; Pedicle Screws ; Spinal Fusion ; Spondylosis ; Surgery, Computer-Assisted