A Comprehensive Analysis of Potential Complications after OLIF : A Review of Postoperative Magnetic Resonance Scans in Over 400 Cases.

Objective: This study focuses on identifying potential complications following oblique lumbar interbody fusion (OLIF) through routine magnetic resonance (MR) scans. Methods: From 650 patients who underwent OLIF from April 2018 to April 2022, this study included those with MR scans taken one-week post-operatively, and only for indirect decompression patients. The analysis evaluated postoperative MR images for hematoma, cage insertion angles, and indirect decompression efficiency. Patient demographics, post-operatively symptoms, and complications were also evaluated. Results: Out of 401 patients enrolled, most underwent 1- or 2-level OLIF. Common findings included approach site hematoma (65.3%) and contralateral psoas hematoma (19%). The caudal level OLIF was related with less orthogonality and deep insertion of cage. Incomplete indirect decompression occurred in 4.66% of cases but did not require additional surgery. Rare but symptomatic complications included remnant disc rupture (4 cases, 1%) and synovial cyst rupture (4 cases, 1%). Conclusion: This study has identified potential complications associated with OLIF, including approach site hematoma, contralateral psoas hematoma, cage malposition risk at caudal levels, and radiologically insufficient indirect decompression. Additionally, it highlights rare, yet symptomatic complications such as remnant disc rupture and synovial cyst rupture. These findings contribute insights into the relatively under-explored area of OLIF complications.

Three-Dimensional Quantitative Assessment of Pedicle Screw Accuracy in Clinical Utilization of a New Robotic System in Spine Surgery: A Multicenter Study.

OBJECTIVE: The objective of this study was to evaluate the accuracy of pedicle screw placement in patients undergoing percutaneous pedicle screw fixation with robotic guidance, using a newly developed 3-dimensional quantitative measurement system. The study also aimed to assess the clinical feasibility of the robotic system in the field of spinal surgery. METHODS: A total of 113 patients underwent pedicle screw insertion using the CUVIS-spine pedicle screw guide system (CUREXO Inc.). Intraoperative O-arm images were obtained, and screw insertion pathways were planned accordingly. Image registration was performed using paired-point registration and iterative closest point methods. The accuracy of the robotic-guided pedicle screw insertion was assessed using 3-dimensional offset calculation and the Gertzbein-Robbins system (GRS). RESULTS: A total of 448 screws were inserted in the 113 patients. The image registration success rate was 95.16%. The average error of entry offset was 2.86 mm, target offset was 2.48 mm, depth offset was 1.99 mm, and angular offset was 3.07°. According to the GRS grading system, 88.39% of the screws were classified as grade A, 9.60% as grade B, 1.56% as grade C, 0.22% as grade D, and 0.22% as grade E. Clinically acceptable screws (GRS grade A or B) accounted for 97.54% of the total, with no reported neurologic complications. CONCLUSION: Our study demonstrated that pedicle screw insertion using the novel robot-assisted navigation method is both accurate and safe. Further prospective studies are necessary to explore the potential benefits of this robot-assisted technique in comparison to conventional approaches.

Surgical Treatment for Degenerative Lumbar Disease With Neurologic Deficits: Comparison Between Oblique Lumbar Interbody Fusion and Posterior Lumbar Interbody Fusion.

Objective: This study aimed to compare the radiological and clinical outcomes of oblique lumbar interbody fusion (OLIF) and posterior lumbar interbody fusion (PLIF) surgeries and to confirm the effects of additional partial laminectomy on the surgical outcomes of OLIF. Methods: This retrospective study included 130 patients who underwent OLIF or PLIF for single-level fusion. Among them, 42 patients underwent PLIF and open pedicle screw fixation and 88 underwent OLIF and percutaneous pedicle screw fixation. In the OLIF group, 42 patients received additional neural decompression through partial laminectomy and discectomy (direct OLIF), whereas the remaining 46 patients did not (indirect OLIF). To measure the neurological deficits, the clinical outcomes were evaluated using a visual analog scale for back and leg pain and the Oswestry Disability Index. Radiologic outcomes were evaluated based on the disc and foraminal heights as well as the segmental lordotic and lumbar lordotic angles. Results: The improvement in the clinical outcomes did not differ significantly among the 3 groups. Radiologically, the 2 OLIF groups showed statistically significant improvements in the disc and foraminal heights when compared with the PLIF group. The PLIF group showed a significant decrease in the disc height and segmental lordotic angle when compared with the OLIF group in the postoperative 1-year period. Conclusion: Both OLIF and PLIF showed similar clinical outcomes in the single-level lumbar fusion. However, OLIF grafts showed an advantage over PLIF with respect to the radiographic outcomes and complication rates. Additionally, partial laminectomy did not significantly affect the radiological results.

Which factor can predict the effect of indirect decompression using oblique lumbar interbody fusion?

The aim of this study was to investigate the association between various factors of indirect decompression. Previous studies have demonstrated the effectiveness of indirect decompression. There is no consensus regarding the predictive factors for indirect decompression. Facet joint gap (FJG) and bulging disc thickness (BDT) have never been considered as factors in other studies. We retrospectively reviewed 62 patients who underwent OLIF L4/5 between April 2018 and September 2020. The relationships between cross-sectional area (CSA) change, CSA change ratio, spinal stenosis grade, and various factors were studied. Various factors related to indirect decompression, such as ligament flavum thickness (LFT), foraminal area (FA), disc height (DH), bulging disc thickness(BDT), and facet joint gap (FJG), were measured. CSA increased from 69.72 mm2 preoperatively to 115.95 mm2 postoperatively (P < .001). BDT decreased from 4.97 mm preoperatively to 2.56 mm postoperatively (P < .001). FJG (Right) increased from 2.99 mm preoperatively to 4.38 mm postoperatively (P < .001). FJG (Left) increased from 2.95 mm preoperatively to 4.52 mm postoperatively (P < .001). The improvement of spinal stenosis grade was as follows: 1 point up group, 38 patients; 2 point up groups, 19 patients; and 3 point up groups, 3 patients. The correlation factors were prespinal stenosis grade (0.723, P < .00), CSA change (0.490, P < .00), and FJG change ratio (left, 0.336, P < .008). FJG showed statistical significance with indirect decompression. Indirect decompression principles might be utilized in patients with severe spinal canal stenosis (even grade 4).

Multicentre randomised controlled clinical trial of electroacupuncture with usual care for patients with non-acute pain after back surgery.

BACKGROUND: The purpose of this study was to investigate the effectiveness and safety between electroacupuncture (EA) combined with usual care (UC) and UC alone for pain reduction and functional improvement in patients with non-acute low back pain (LBP) after back surgery. METHODS: In this multicentre, randomised, assessor-blinded active-controlled trial, 108 participants were equally randomised to either the EA with UC or the UC alone. Participants in the EA with UC group received EA treatment and UC treatment twice a week for 4 weeks; those allocated to the UC group received only UC. The primary outcome was the VAS pain intensity score. The secondary outcomes were functional improvement (Oswestry Disability Index [ODI]) and the quality of life (EuroQol-5-dimension questionnaire [EQ-5D]). The outcomes were measured at Week 5. RESULTS: Significant reductions were observed in the VAS (mean difference [MD] -8.15; P=0.0311) and ODI scores (MD -3.98; P=0.0460) between two groups after 4 weeks of treatment. No meaningful differences were found in the EQ-5D scores and incidence of adverse events (AEs) between the groups. The reported AEs did not have a causal relationship with EA treatment. CONCLUSIONS: The results showed that EA with UC treatment was more effective than UC alone and relatively safe in patients with non-acute LBP after back surgery. EA with UC treatment may be considered as an effective, integrated, conservative treatment for patients with non-acute LBP after back surgery. CLINICAL TRIAL REGISTRATION: KCT0001939.

Risk Factors of Allogenous Bone Graft Collapse in Two-Level Anterior Cervical Discectomy and Fusion.

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is commonly used surgical procedure for cervical degenerative disease. Among the various intervertebral spacers, the use of allografts is increasing due to its advantages such as no harvest site complications and low rate of subsidence. Although subsidence is a rare complication, graft collapse is often observed in the follow-up period. Graft collapse is defined as a significant graft height loss without subsidence, which can lead to clinical deterioration due to foraminal re-stenosis or segmental kyphosis. However, studies about the collapse of allografts are very limited. In this study, we evaluated risk factors associated with graft collapse. METHODS: We retrospectively reviewed 33 patients who underwent two level ACDF with anterior plating using allogenous bone graft from January 2013 to June 2017. Various factors related to cervical sagittal alignment were measured preoperatively (PRE), postoperatively (POST), and last follow-up. The collapse was defined as the ratio of decrement from POST disc height to follow-up disc height. We also defined significant collapses as disc heights that were decreased by 30% or more after surgery. The intraoperative distraction was defined as the ratio of increment from PRE disc height to POST disc height. RESULTS: The subsidence rate was 4.5% and graft collapse rate was 28.8%. The pseudarthrosis rate was 16.7% and there was no association between pseudarthrosis and graft collapse. Among the collapse-related risk factors, pre-operative segmental angle (p=0.047) and intra-operative distraction (p=0.003) were significantly related to allograft collapse. The cut-off value of intraoperative distraction ≥37.3% was significantly associated with collapse (p=0.009; odds ratio, 4.622; 95% confidence interval, 1.470-14.531). The average time of events were as follows: collapse, 5.8±5.7 months; subsidence, 0.99±0.50 months; and instrument failure, 9.13±0.50 months. CONCLUSION: We experienced a higher frequency rate of collapse than subsidence in ACDF using an allograft. Of the various preoperative factors, intra-operative distraction was the most predictable factor of the allograft collapse. This was especially true when the intraoperative distraction was more than 37%, in which case the occurrence of graft collapse increased 4.6 times. We also found that instrument failure occurs only after the allograft collapse.

Electroacupuncture as a complement to usual care for patients with non-acute low back pain after back surgery: a pilot randomised controlled trial.

OBJECTIVES: The aim of this pilot study was to estimate the sample size for a large pragmatic study of the comparative effectiveness of electroacupuncture (EA) for low back pain (LBP) after back surgery. DESIGN: A randomised, active-controlled, assessor-blinded trial. PARTICIPANTS: Patients with recurrent or persistent LBP, defined as a Visual Analogue Scale (VAS) score of ≥50 mm, with or without leg pain after back surgery. INTERVENTIONS: Patients were randomised to an EA plus usual care (UC) group or to a UC alone group at a 1:1 ratio. Patients assigned to each group received UC, including drug therapy, physical therapy and back pain education, twice a week for 4 weeks; those assigned to the EA plus UC group additionally received EA. OUTCOME MEASURES: The primary outcome was severity of LBP as measured by VAS. Secondary outcomes included back pain-related disability, assessed using the Oswestry Disability Index (ODI) and quality of life, assessed using the EuroQol Five Dimensions (EQ-5D) questionnaire. Statistical analysis was performed using paired and independent t-tests. A p value of <0.05 was considered statistically significant. RESULTS: Thirty-nine patients were allocated to receive EA plus UC (n=18) or UC alone (n=21). There was no statistically significant difference in VAS or EQ-5D scores between the two groups, but there was a significant decrease in ODI scores (p=0.0081). Using G*Power, it was calculated that 40 participants per group would be needed for a future trial according to VAS scores. Considering for a 25% dropout rate, 108 participants (54 per group) would be needed. CONCLUSIONS: A future trial addressing the risk of bias and including the estimated sample size would allow for better clinical assessment of the benefits of EA plus UC in treatment of patients with non-acute pain after back surgery. TRIAL REGISTRATION NUMBER: NCT01966250; Results.

A multi-center, randomized controlled clinical trial, cost-effectiveness and qualitative research of electroacupuncture with usual care for patients with non-acute pain after back surgery: study protocol for a randomized controlled trial.

BACKGROUND: Although pain after back surgery is known to be difficult to control, various treatment options are available to patients and physicians. A protocol for a confirmatory randomized controlled trial (RCT) on pain and function after back surgery was designed based on the results of a pilot trial. The aim of this study is to compare the effectiveness and safety of electroacupuncture (EA) with usual care (UC) versus UC alone on pain control and functional improvement after back surgery. METHODS/DESIGN: This study is a multi-center, randomized, assessor-blinded trial with an active control conducted in conjunction with a cost-effectiveness analysis and qualitative research. Participants with non-acute low back pain with or without leg pain after back surgery who have a Visual Analogue Scale (VAS) pain intensity score ≥ 50 mm will be randomly assigned to either the EA with UC group (n = 54) or the UC group (n = 54). Following randomization, participants in both groups will receive the same UC treatment twice a week for a four-week treatment period. Participants assigned to the EA with UC group will additionally receive EA twice a week for the same four-week period. The primary outcome measure will be assessed using a VAS pain intensity score for low back pain. The secondary outcomes will include the Oswestry Disability Index, EuroQol 5-Dimension score, and drug intake. The primary and secondary outcomes will be measured at one, four, and eight weeks post randomization. DISCUSSION: The results of this study will provide evidence of the effectiveness and cost-effectiveness of EA in managing postoperative pain following back surgery. In addition, the qualitative research results will help improve the quality of integrative medical interventions. TRIAL REGISTRATION: Clinical Research Information Service (CRIS), Republic of Korea, KCT0001939 . Registered on 8 June 2016.

Electroacupuncture as a complement to usual care for patients with non-acute pain after back surgery: a study protocol for a pilot randomised controlled trial.

INTRODUCTION: Recurrent or persistent low back pain is common after back surgery but is typically not well controlled. Previous randomised controlled trials on non-acute pain after back surgery were flawed. In this article, the design and protocol of a randomised controlled trial to treat pain and improve function after back surgery are described. METHODS AND ANALYSIS: This study is a pilot randomised, active-controlled, assessor-blinded trial. Patients with recurring or persistent low back pain after back surgery, defined as a visual analogue scale value of ≥50 mm, with or without leg pain, will be randomly assigned to an electroacupuncture-plus-usual-care group or to a usual-care-only group. Patients assigned to both groups will have usual care management, including physical therapy and patient education, twice a week during a 4-week treatment period that would begin at randomisation. Patients assigned to the electroacupuncture-plus-usual-care group will also have electroacupuncture twice a week during the 4-week treatment period. The primary outcome will be measured with the 100 mm pain visual analogue scale of low back pain by a blinded evaluator. Secondary outcomes will be measured with the EuroQol 5-Dimension and the Oswestry Disability Index. The primary and secondary outcomes will be measured at 4 and 8 weeks after treatment. ETHICS AND DISSEMINATION: Written informed consent will be obtained from all participants. This study was approved by the Institutional Review Board (IRB) of Pusan National University Korean Hospital in September 2013 (IRB approval number 2013012). The study findings will be published in peer-reviewed journals and presented at national and international conferences. TRIAL REGISTRATION NUMBER: This trial was registered with the US National Institutes of Health Clinical Trials Registry: NCT01966250.