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.

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).

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.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2461-6) contains supplementary material, which is available to authorized users.

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.

Enhanced neutrophil functions by recombinant human granulocyte colony-stimulating factor in diabetic patients with foot infections in vitro

This study was performed to evaluate the effect of granulocyte-colony stimulating factor on neutrophil functions in diabetic patients with active foot infections in vitro. Twelve diabetic patients with foot infections and 12 normal volunteers were enrolled. Neutrophils from peripheral blood were incubated with granulocyte colony-stimulating factor (G-CSF, 50 ng/mL) for 20 min. Superoxide production of neutrophils was measured by the reduction of ferricytochrome C. Neutrophil phagocytosis was assayed using Staphylococcus aureus and the weighted phagocytic index was calculated. Superoxide production of neutrophils in diabetic patients with foot infections was 7.7 (unit: nmol/2 x 10(5) cells/60 min), which was significantly lower than that in controls (12.0) (p<0.05). G-CSF increased neutrophil superoxide production to 12.1 in diabetic patients with foot infections and to 19.8 in controls (p<0.05 for each). Weighted phagocytic index in diabetic patients with foot infections was 0.77, which was not significantly different from that of the controls (0.69). Weighted phagocytic index was increased significantly by G-CSF to 0.88 in diabetic patients with foot infections and to 0.79 in controls (p<0.05 for each). In conclusion, G-CSF significantly enhanced neutrophil functions in diabetic patients with foot infections in vitro.

Effect of stem cell factor, interleukin-6, nitric oxide and transforming growth factor-beta on the osteoclast differentiation induced by 1 alpha,25-(OH)2D3 in primary murine bone marrow cultures

Osteotropic hormones and cytokines are involved in the differentiation of osteoclast progenitors from haematopoietic stem cells to multinucleated osteoclasts which mediate bone resorption. Stem cell factor, interleukin-6, nitric oxide, and transforming growth factor-beta are implicated in the regulation of bone resorption by osteoclast. We test whether stem cell factor, interleukin-6, nitric oxide, and transforming growth factor-beta affect the generation of osteoclast-like multi-nucleated cells induced by 1 alpha,25-(OH)2D3. 1 alpha,25-(OH)2D3 increase the generation of osteoclast-like cells retaining osteoclast characteristics including multinuclearity and positive staining for tartrate-resistant acid phosphatase. Combined treatment of stem cell factor with interleukin-6 synergistically potentiates the ability of 1 alpha,25-(OH)2D3 to generate tartrate-resistant acid phosphatase-positive multinucleated cells. However, either stem cell factor or interleukin-6 alone does not induce the generation of tartrate-resistant acid phosphatase-positive multinucleated cells. Transforming growth factor-beta produces a biphasic effect on osteoclast generation induced by 1 alpha,25-(OH)2D3. Transforming growth factor-beta stimulates osteoclast generation at low concentration (0.1 ng/ml) whereas it suppresses the formation of osteoclast-like cell at higher concentration (1 ng/ml). Sodium nitroprusside, a donor of nitric oxide, almost completely inhibits the generation of 1 alpha,25-(OH)2D3-induced osteoclast at high concentration (100 microM), but it significantly enhances the osteoclast generation at low concentrations (3 microM). These results suggest that stem cell factor, interleukin-6, transforming growth factor-beta, and nitric oxide interact with 1 alpha,25-(OH)2D3 to modulate the differentiation of hematopoietic precursors toward committed osteoclast precursors.