BACKGROUND: Establishing thresholds of change that are actually meaningful for the patient in an outcome measurement instrument is paramount. This concept is called the minimum clinically important difference (MCID). We summarize available MCID calculation methods relevant to spine surgery, and outline key considerations, followed by a step-by-step working example of how MCID can be calculated, using publicly available data, to enable the readers to follow the calculations themselves.
METHODS: Thirteen MCID calculations methods were summarized, including anchor-based methods, distribution-based methods, Reliable Change Index, 30% Reduction from Baseline, Social Comparison Approach and the Delphi method. All methods, except the latter two, were used to calculate MCID for improvement of Zurich Claudication Questionnaire (ZCQ) Symptom Severity of patients with lumbar spinal stenosis. Numeric Rating Scale for Leg Pain and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire Walking Ability domain were used as anchors.
RESULTS: The MCID for improvement of ZCQ Symptom Severity ranged from 0.8 to 5.1. On average, distribution-based methods yielded lower MCID values, than anchor-based methods. The percentage of patients who achieved the calculated MCID threshold ranged from 9.5% to 61.9%.
CONCLUSIONS: MCID calculations are encouraged in spinal research to evaluate treatment success. Anchor-based methods, relying on scales assessing patient preferences, continue to be the \"gold-standard\" with receiver operating characteristic curve approach being optimal. In their absence, the minimum detectable change approach is acceptable. The provided explanation and step-by-step example of MCID calculations with statistical code and publicly available data can act as guidance in planning future MCID calculation studies.

Background: Anterior lumbar interbody fusion (ALIF) and posterior spinal fusion (PSF) play pivotal roles in restoring lumbar lordosis in spinal surgery. There is an ongoing debate between combined single-position surgery and traditional prone-position PSF for optimizing segmental lumbar lordosis. Methods: This retrospective study analyzed 59 patients who underwent ALIF in the supine position followed by PSF in the prone position at a single institution. Cobb angles were measured preoperatively, post-ALIF, and post-PSF using X-ray imaging. One-way repeated measures ANOVA and post-hoc analyses with Bonferroni adjustment were employed to compare mean Cobb angles at different time points. Cohen\'s d effect sizes were calculated to assess the magnitude of changes. Sample size calculations were performed to ensure statistical power. Results: The mean segmental Cobb angle significantly increased from preoperative (32.2 ± 13.8 degrees) to post-ALIF (42.2 ± 14.3 degrees, Cohen\'s d: -0.71, p < 0.0001) and post-PSF (43.6 ± 14.6 degrees, Cohen\'s d: -0.80, p < 0.0001). There was no significant difference between Cobb angles after ALIF and after PSF (Cohen\'s d: -0.10, p = 0.14). The findings remained consistent when Cobb angles were analyzed separately for single-screw and double-screw ALIF constructs. Conclusions: Both supine ALIF and prone PSF significantly increased segmental lumbar lordosis compared to preoperative measurements. The negligible difference between post-ALIF and post-PSF lordosis suggests that supine ALIF followed by prone PSF can be an effective approach, providing flexibility in surgical positioning without compromising lordosis improvement.

UNASSIGNED: Deep Vein Thrombosis (DVT) is a significant medical concern characterized by the formation of blood clots within the venous system. Surgical procedures are known to increase the risk of DVT. While enoxaparin has proven to be highly effective in treating DVT, concerns about bleeding and accurate dosage regulation may restrict its application. Recent research has focused on aspirin\'s potential in preventing DVT after various surgeries. This study aimed to determine whether aspirin was as effective as enoxaparin in preventing DVT after spine surgery.
UNASSIGNED: This randomized controlled trial enrolled study patients who underwent spine surgery at Shahid Kamyab Emergency Hospital in Mashhad, and had a Caprini score > 5, indicating a higher risk of DVT. In the control group, patients received subcutaneous injections of enoxaparin at a dosage of 40 mg, while the intervention group received oral aspirin tablets with a daily dosage of 81 mg. An experienced radiologist performed a Doppler ultrasound of the lower limbs\' veins seven days after surgery to diagnose DVT. The outcomes of the two groups were then compared.
UNASSIGNED: A total of 100 patients participated in the clinical trial and were equally assigned to the aspirin and enoxaparin groups. Both groups were homogeneous regarding the basic and clinical characteristics. The incidence of postoperative DVT was 4.0% in the aspirin group and 10.0% in the enoxaparin group (p=0.092). The incidence of hemorrhage was 2.0% in the aspirin group and 4.0% in the enoxaparin group (p=0.610).
UNASSIGNED: These findings indicate that aspirin may be a promising alternative to enoxaparin for DVT prevention after surgery, but additional research is essential to validate these results and further assess the benefits and risks associated with aspirin usage in this context.

OBJECTIVE: Hyponatraemia increases the morbidity and mortality risks of orthopaedic patients. When undergoing spine surgery, hyponatraemic patients have high risks of pneumonia and of staying in hospital for up to 1 day longer compared with non-hyponatraemic patients. This study aims to assess the occurrence of adverse events among patients with pre-operative hyponatraemia after undergoing lumbar surgery.
METHODS: A retrospective cohort study was conducted. Patients who underwent spinal surgery in 2011 to 2013 were identified from the American College of Surgeons National Surgical Quality Improvement Program database. Multivariate analysis was conducted to demonstrate the difference in post-operative complication rates between hyponatraemic patients and normonatraemic patients. Post-operative adverse events, need for blood transfusion and length of stay were considered as clinical outcome data.
RESULTS: A total of 58,049 patients were included; pre-operatively, 55,012 (94.8%) were normonatraemic and 3037 (5.2%) were hyponatraemic. Multivariate analysis showed that hyponatraemic patients had higher rates of adverse events, blood transfusions and urinary tract infections. Specifically, 632 (20.8%) hyponatraemic patients developed adverse events, compared with 6821 (12.4%) normonatraemic patients; the hyponatraemic patients received transfusions, compared with 6821 (7.4%) normonatraemic patients; and 97 (3.2%) hyponatraemic patients developed urinary tract infections, compared with 715 (1.3%) normonatraemic patients. Finally, an extended length of stay beyond 6 days occurred in 604 (19.9%) hyponatraemic patients, compared with 4676 (8.5%) normonatraemic patients.
CONCLUSIONS: Our study identified an association between pre-operative hyponatraemia and post-operative adverse events in spinal surgery patients. However, it is unclear whether hyponatraemia caused the higher adverse event rate.

BACKGROUND: The association between nonsteroidal anti-inflammatory drugs (NSAIDs) and postoperative acute kidney injury (AKI) remains controversial, with limited studies specifically examining flurbiprofen. Therefore, this research aimed to investigate the association between intraoperative flurbiprofen administration and postoperative AKI.
METHODS: We retrospectively identified a cohort of patients at the Third Xiangya Hospital of Central South University. A total of 3882 adult patients undergoing spinal surgery between January 1, 2012, and July 31, 2018, were included and classified into two groups: those receiving flurbiprofen (50 or 100 mg once, 5 min after anesthesia start) and those not receiving flurbiprofen. The primary endpoint was the incidence of AKI.
RESULTS: The flurbiprofen group (4.4%) had a lower incidence of AKI compared to the non-flurbiprofen group (6.5%, P < 0.001). After adjusting for potential confounding variables, the multivariable regression analysis showed that the flurbiprofen group had a 49% reduced risk of postoperative AKI (OR 0.51; 95% CI 0.31 to 0.82) compared to the non-flurbiprofen group. Subgroup analysis indicated that flurbiprofen injection was associated with a reduced incidence of postoperative AKI in patients without diabetes (OR 0.61; 95% CI 0.19 to 0.74), surgical times of 2-5 h (OR 0.54; 95% CI 0.23 to 0.75), and preoperative anemia (OR 0.57; 95% CI 0.21 to 0.74).
CONCLUSIONS: The study concluded that perioperative flurbiprofen treatment was associated with a lower risk of postoperative AKI in adult patients undergoing spinal surgery.

OBJECTIVE: Using patient-reported outcome measures (PROMs), this study was undertaken to determine how well patients with early onset scoliosis (EOS) fare in adulthood.
METHODS: Among eight healthcare centers, 272 patients (≥ 18 years) surgically managed for EOS (≥ 5 years) completed the Scoliosis Research Society (SRS)-22r, Functional Assessment of Chronic Illness Therapy-10 (FACIT-Dyspnea-10), and Short Form (SF)-12. Functional and demographic data were collected.
RESULTS: The response rate was 40% (108/272). EOS etiologies were congenital (45%), neuromuscular (20%), idiopathic (20%) syndromic (11%), and unknown (4%). All patients scored within normal limits on the FACIT-Dyspnea-10 pulmonary (no breathing aids, 78%; no oxygen, 92%). SF-12 physical health scores and most SRS-22r domains were significantly decreased (p < 0.05 and p < 0.001, respectively) compared with normative values. SF-12 and SRS-22r mental health scores (MHS) were lower than normative values (p < 0.05 and p < 0.02, respectively). Physical health PROMs varied between etiologies. Treatment varied by etiology. Patients with congenital EOS were half as likely to undergo definitive fusion. There was no difference between EOS etiologies in SF-12 MHS, with t scores being slightly lower than normative peers.
CONCLUSIONS: Good long-term physical and social function and patient-reported quality of life were noted in surgically managed patients. Patients with idiopathic EOS physically outperformed those with other etiologies in objective and PROM categories but had similar MHS PROMs. Compared to normative values, EOS patients demonstrated decreased long-term physical capacity, slightly lower MHS, and preserved cardiopulmonary function.
METHODS: Level IV Case Series.

BACKGROUND: Flash visual evoked potentials (FVEPs) are a reliable method for protecting visual function during spine surgery in prone position. However, the popularization and application of FVEPs remain limited due to the unclear influence of various anesthetics on FVEPs. Exploring the effects of anesthetic drugs on FVEP and establishing appropriate anesthesia maintenance methods are particularly important for promoting and applying FVEP. According to the conventional concept, inhaled narcotic drugs significantly affect the success of FVEP monitoring, FVEP extraction, and interpretation. Nonetheless, our previous study demonstrated that sevoflurane-propofol balanced anesthesia was a practicable regimen for FVEPs. Desflurane is widely used in general anesthesia for its rapid recovery properties. As the effect of desflurane on FVEP remains unclear, this trial will investigate the effect of different inhaled concentrations of desflurane anesthesia on amplitude of FVEPs during spine surgery, aiming to identify more feasible anesthesia schemes for the clinical application of FVEP.
UNASSIGNED: A total of 70 patients undergoing elective spinal surgery will be enrolled in this prospective, randomized controlled, open-label, patient-assessor-blinded, superiority trial and randomly assigned to the low inhaled concentration of desflurane group (LD group) maintained with desflurane-propofolremifentanil-balanced anesthesia or high inhaled concentration of desflurane group (HD group) maintained with desflurane-remifentanil anesthesia maintenance group at a ratio of 1:1. All patients will be monitored for intraoperative FVEPs, and the baseline will be measured half an hour after induction under total intravenous anesthesia (TIVA). After that, patients will receive 0.5 minimum alveolar concentration (MAC) of desflurane combined with propofol and remifentanil for anesthesia maintenance in the LD group, while 0.7-1.0 MAC of desflurane and remifentanil will be maintained in the HD group. The primary outcome is the N75-P100 amplitude 1 h after the induction of anesthesia. We intend to use the dual measure evaluation, dual data entry, and statistical analysis by double trained assessors to ensure the reliability and accuracy of the results.
CONCLUSIONS: This randomized controlled trial aims to explore the superiority effect of low inhaled concentration of desflurane combined with propofolremifentanil-balanced anesthesia versus high inhaled concentration of desflurane combined with remifentanil anesthesia on amplitude of FVEPs. The study is meant to be published in a peer-reviewed journal and might guide the anesthetic regimen for FVEPs. The conclusion is expected to provide high-quality evidence for the effect of desflurane on FVEPs and aim to explore more feasible anesthesia schemes for the clinical application of FVEPs and visual function protection.
BACKGROUND: This study was registered on clinicaltrials.gov on July 15, 2022.
RESULTS: gov Identifier: NCT05465330.

UNASSIGNED: Wound complications after lumbar spine surgery may result in prolonged hospitalization and increased morbidity. Early identification can trigger appropriate management.
UNASSIGNED: The aim of this study was to investigate the efficacy of infrared-based wound assessment (FLIR) after lumbar spine surgery in the context of identifying wound healing disorders.
UNASSIGNED: 62 individuals who underwent lumbar spine surgery were included. The immediate postoperative course was studied, and the patient\'s sex, age, body mass index (BMI), heart rate, blood pressure, body temperature, numeric rating scale for pain (NRS), C-reactive protein (CRP), leukocyte, and hemoglobin levels were noted and compared to thermographic measurement of local surface temperature in the wound area.
UNASSIGNED: Measurement of local surface temperature in the wound area showed a consistent temperature distribution while it was uneven in case of wound healing disorder. In this instance, the region of the wound where the wound healing disorder occured had a lower temperature than the surrounding tissue (p> 0.05).
UNASSIGNED: This study demonstrates the ongoing importance of clinical wound assessment for early detection of complications. While laboratory parameter measurement is crucial, FLIR may serve as a cost-effective supplemental tool in clinical wound evaluation. Patient safety risks appear minimal since local ST is measured without touch.

Background and objectives Mixed reality (MR) is one of the image processing technologies that allows the user to manipulate three-dimensional (3D) virtual images (hologram). The aim of this study was to evaluate the accuracy of MR-based pedicle screw (PS) placement using 3D spine models. Materials and methods Using the preoperative CT data of a patient with adolescent idiopathic scoliosis (AIS) who had undergone posterior spinal fusion in our hospital, a 3D-printed spine model was created. On the other hand, a 3D hologram of the same patient was automatically created using the preoperative CT data uploaded to the Holoeyes MD service website (Holoeyes Inc., Tokyo, Japan). Using a Magic Leap One® headset (Magic Leap Inc., Plantation, FL), the 3D hologram with lines of predetermined PS trajectories was superimposed onto the 3D-printed spine model and PS were inserted bilaterally along with the trajectory lines from T5 to L3. As a control, we used a readymade 3D spine model of AIS and inserted PS bilaterally with a freehand technique from T4 to L3. The rate of pedicle violation was compared between the MR-based and freehand techniques. Results A total of 22 and 24 PS were placed into the 3D-printed spine model of our patient and the readymade 3D spine model, respectively. The rate of pedicle violation was 4.5% (1/22 screws) in the MR-based technique and 29.2% (7/24 screws) in the freehand technique (P = 0.049). Conclusions We demonstrated a significantly lower rate of PS misplacement in the MR-based technique than in the freehand technique. Therefore, an MR-assisted system is a promising tool for PS placement in terms of feasibility, safety, and accuracy, warranting further studies including cadaveric and clinical studies.

OBJECTIVE: Multimodal pain management is one component in enhanced recovery after surgery protocol. Here we evaluate the efficacy of tramadol-paracetamol in acute postoperative pain and pain outcome at 12 months after spine surgery in randomized, double-blind, placebo-controlled trial.
METHODS: We randomized 120 patients undergoing spine surgery to receive, for add-on pain management, two tramadol-paracetamol 37.5 mg/325 mg (n = 61) or placebo tablets (n = 59) twice a day for 5 postoperative days. In the hospital, multimodal pain management consisted of dexketoprofen and oxycodone. After discharge, patients were prescribed ibuprofen 200 mg, maximum 1,200 mg/day. Pain, analgesic use, and satisfaction with pain medication were followed up with the Brief Pain Inventory questionnaire before surgery and at 1 and 52 weeks after surgery. The primary outcome was patients\' satisfaction with pain medication 1 week after surgery.
RESULTS: At 1 week after surgery, patients\' satisfaction with pain medication was similarly high in the two groups, 75% [interquartile range, 30%] in the placebo group and 70% [40%] in the tramadol-paracetamol group (p = 0.949) on a scale: 0% =  not satisfied, 100% = totally satisfied. At 1 week, ibuprofen dose was lower in the placebo group 200 mg [1,000] compared to the tramadol-paracetamol group, 800 mg [1,600] (p = 0.016). There was no difference in the need for rescue oxycodone. Patients in the tramadol-paracetamol group had more adverse events associated with analgesics during the first postoperative week (relative risk = 1.8, 95% confidence interval, 1.2-2.6).
CONCLUSIONS: Add-on pain treatment with tramadol-paracetamol did not enhance patients\' satisfaction with early pain management after back surgery.