Large-Scale Comparative Study Between Microendoscopic Laminectomy and Full-Endoscopic Laminectomy for the Treatment of Single-Level Lumbar Spinal Canal Stenosis.

BACKGROUND: We previously compared the operative outcomes of microendoscopic laminectomy (MEL) and full-endoscopic laminectomy (FEL) for single-level lumbar spinal canal stenosis (LSCS). In this initial report, the operative outcomes of FEL were not inferior to those of MEL. OBJECTIVE: The purpose of this study is to compare the outcomes of MEL and FEL for single-level LSCS on a large scale using widely used multiple evaluation methods. METHODS: MEL was performed using a 16 mm tubular retractor and an endoscope, while FEL was performed using a 6.4 mm working channel endoscope. A retrospective study was performed on patients with LSCS treated with MEL (n = 355) or FEL (n = 154). Patient background and operative data were also collected. The Oswestry Disability Index (ODI), European Quality of Life-5 Dimensions (EQ-5D), and 36-item Short Form Survey (SF-36) scores were recorded preoperatively and 1-year postoperatively. RESULTS: Background data of the two groups and the mean operation time (MEL, 72.1 m; FEL, 74.2 m) were not significant (p>0.2). The mean volumes of intraoperative bleeding (MEL, 25.2 ml; FEL, 10.3 ml) were significantly different (p<0.001). The mean postoperative hospital stays (MEL, 3.9 days; FEL, 2.1 days) were significantly different (p<0.001). Fifteen dural tears (MEL, 11; FEL, 4) and 1 surgical site infection (MEL, 1; FEL, 0) were observed but not significant (p>0.5). Reoperation was required for postoperative hematoma in five patients (MEL, 3; FEL, 2). Although the ODI, EQ-5D, and SF-36 scores improved significantly at one year postoperatively in the MEL and FEL groups (p<0.001), there were no significant differences between the two groups (p>0.1). CONCLUSION: The operative outcomes and minimal invasiveness were no statistical difference between the MEL and FEL groups. Further development of the operative techniques and the instruments of FEL are required to shorten the operation time.

A new surgical method to treat intracanal lumbar disc herniation using the unilateral biportal endoscopic transforaminal approach: patient series.

BACKGROUND: Unilateral biportal endoscopic lumbar discectomy (UBELD) is a new minimally invasive spine surgery. The purpose of this study is to describe a new surgical method to treat intracanal lumbar disc herniation (LDH) using the unilateral biportal endoscopic transforaminal approach (UBE-TFA). The first 15 patients who had undergone UBELD for single-level LDH were included in this study. Operative time, intraoperative blood loss, postoperative stay, and intraoperative complications were recorded. The Oswestry Disability Index (ODI), numeric rating scale (NRS) score for leg pain, and modified MacNab criteria were assessed at 3 months postoperatively. OBSERVATIONS: The mean operative time was 52.0 ± 13.8 minutes. The mean intraoperative blood loss was 10.5 ± 10.2 mL. The mean postoperative stay was 1.1 ± 0.3 days. There were no complications. The postoperative mean ODI was significantly improved from 44.9 ± 14.4 to 7.7 ± 11.2 at the final follow-up (p < 0.001). There was a significant decrease in the postoperative mean NRS score for leg pain, from 6.1 ± 1.9 to 0.8 ± 1.3 at the final follow-up (p < 0.001). Based on the modified MacNab criteria, good to excellent results were obtained in 86.7% of the patients. LESSONS: We considered UBELD-TFA as not only one of the promising surgical methods for UBELD, but also a new surgical implementation of the TFA.

Does surgical site infection affect patient-reported outcomes after spinal surgery? A multicenter cohort study.

BACKGROUND: Surgical site infections are common in spinal surgeries. It is uncertain whether outcomes in spine surgery patients with vs. without surgical site infection are equivalent. Therefore, we assessed the effects of surgical site infection on postoperative patient-reported outcomes. METHODS: We enrolled patients who underwent elective spine surgery at 12 hospitals between April 2017 and February 2020. We collected data regarding the patients' backgrounds, operative factors, and incidence of surgical site infection. Data for patient-reported outcomes, namely numerical rating scale, Neck Disability Index/Oswestry Disability Index, EuroQol Five-Dimensional questionnaire, and 12-Item Short-Form Health Survey scores, were obtained preoperatively and 1 year postoperatively. We divided the patients into with and without surgical site infection groups. Multivariate logistic regression analyses were performed to identify the risk factors for surgical site infection. Using propensity score matching, we obtained matched surgical site infection-negative and -positive groups. Student's t-test was used for comparisons of continuous variables, and Pearson's chi-square test was used to compare categorical variables between the two matched groups and two unmatched groups. RESULTS: We enrolled 8861 patients in this study; 74 (0.8 %) developed surgical site infections. Cervical spine surgery and American Society of Anesthesiologists physical status classification ≥3 were identified as risk factors; microendoscopy was identified as a protective factor. Using propensity score matching, we compared surgical site infection-positive and -negative groups (74 in each group). No significant difference was found in postoperative pain or dysesthesia of the lower back, buttock, leg, and plantar area between the groups. When comparing preoperative with postoperative pain and dysesthesia, statistically significant improvement was observed for both variables in both groups (p < 0.01 for all variables). No significant differences were observed in postoperative outcomes between the matched surgical site infection-positive and -negative groups. CONCLUSIONS: Patients with surgical site infections had comparable postoperative outcomes to those without surgical site infections.

A multilocular discal cyst extending from the spinal canal to the extraforaminal region: A case report.

BACKGROUND: Lumbar discal cysts are intraspinal extradural cysts communicating with the intervertebral disc. The usual location and morphology are in the caudal ventrolateral epidural space of the spinal canal, without extension to the neural foramen or crossing the midline and described as a well-defined homogeneous oval or spherical cyst on low and high signal intensities observed in lumbar lesions on T1- and T2-weighted magnetic resonance imaging, respectively. We report an unusual lumbar discal cyst in terms of the lesion location and morphology. CASE PRESENTATION: A 33-year-old-man presented with lower back and right anterior thigh pain. Magnetic resonance imaging revealed multilocular cystic lesions in the cranial ventrolateral epidural space at L2-L3 with low and high signal intensities on T1- and T2-weighted magnetic resonance imaging, respectively. We performed a full-endoscopic transforaminal cystectomy under general anesthesia. CONCLUSION: Lumbar discal cysts should be considered a differential diagnosis for multilocular intraspinal cystic lesion.

Interstitial-fluid shear stresses induced by vertically oscillating head motion lower blood pressure in hypertensive rats and humans.

The mechanisms by which physical exercise benefits brain functions are not fully understood. Here, we show that vertically oscillating head motions mimicking mechanical accelerations experienced during fast walking, light jogging or treadmill running at a moderate velocity reduce the blood pressure of rats and human adults with hypertension. In hypertensive rats, shear stresses of less than 1 Pa resulting from interstitial-fluid flow induced by such passive head motions reduced the expression of the angiotensin II type-1 receptor in astrocytes in the rostral ventrolateral medulla, and the resulting antihypertensive effects were abrogated by hydrogel introduction that inhibited interstitial-fluid movement in the medulla. Our findings suggest that oscillatory mechanical interventions could be used to elicit antihypertensive effects.

Comparison of the Outcomes of Microendoscopic Cervical Foraminotomy versus Full-endoscopic Cervical Foraminotomy for the Treatment of Cervical Radiculopathy.

This study aimed to compare the outcomes of microendoscopic cervical foraminotomy (MECF) versus full-endoscopic cervical foraminotomy (FECF) for treating cervical radiculopathy (CR).A retrospective study was performed on patients with CR treated using MECF (n = 35) or FECF (n = 89). A 16-mm tubular retractor and endoscope was used for MECF, while a 4.1-mm working channel endoscope was used for FECF. Patient background and operative data were collected. The numerical rating scale (NRS) and the Neck Disability Index scores were recorded preoperatively and at 1 year postoperatively. Postoperative subjective satisfaction was also assessed.Although the NRS, and NDI scores, as well as postoperative satisfaction at 1 year considerably improved in both groups, one of the background data (number of operated vertebral level) was significantly different. Therefore, we separately analyzed single- and two-level CR. In single-level CR, operation time, intraoperative bleeding, postoperative stay, NDI after 1 year, and reoperation rate were statistically superior in FECF group. In two-level CR, the postoperative stay was statistically superior in FECF group. Three postoperative hematomas were observed in the MECF group, while none was observed in the FECF group.Operative outcomes did not significantly differ between groups. We did not observe postoperative hematoma in FECF even without placement of a postoperative drain. Therefore, we recommend FECF as the first option for the treatment of CR as it has a better safety profile and is minimally invasive.

Comparison of the Interlaminar and Transforaminal Approaches for Full-endoscopic Discectomy for the Treatment of L4/5 Lumbar Disc Herniation.

This study aims to compare the outcomes of interlaminar and transforaminal approaches for full-endoscopic discectomy (FED) for treating L4/5 lumbar disc herniation (LDH).A retrospective study of patients with L4/5 LDH treated with interlaminar endoscopic lumbar discectomy (IELD, n = 19) or transforaminal endoscopic lumbar discectomy (TELD, n = 105) was conducted. Patient background, radiological findings, and operative data were collected. Oswestry Disability Index (ODI) and European Quality of Life-5 Dimension (EQ-5D) scores were recorded preoperatively and 1 and 2 years postoperatively.Although ODI and EQ-5D scores 1 and 2 years postoperatively improved statistically in the IELD and TELD groups, there were no statistical differences between the groups. IELD was predominantly performed in patients who were taller and heavier. The mean operative times and the frequency of laminectomy for IELD and TELD were 67.2 and 44.6 min and 63.2 and 17.1%, respectively (P < 0.001). The radiological findings showed that the concave configuration of the L4 lamina, interlaminar space width, and foraminal width were statistically different between the groups. There were no complications in either of the groups. Reoperation was required for recurrence in two and five patients in the IELD and TELD groups (P = 0.29), respectively.Operative outcomes were identical between the two groups. Although the operative time was longer in the IELD group, both approaches were safely and effectively performed. Depending on the patient's physique and preoperative radiological findings, the more suitable approach for L4/5 LDH should be chosen.

A Propensity Score-matched Analysis of Clinical Outcomes Between Single-level and Multilevel Intervertebral Decompression for Cervical Radiculopathy.

STUDY DESIGN: Retrospective multicenter study with propensity score matching. OBJECTIVE: To compare the clinical outcomes of single-level and multilevel intervertebral decompression for cervical degenerative radiculopathy. SUMMARY OF BACKGROUND DATA: In patients with cervical radiculopathy, physical examination findings are sometimes inconsistent with imaging data. Multilevel decompression may be necessary for multiple foraminal stenosis. Additional decompression is more invasive yet expected to comprehensively decompress all suspected nerve root compression areas. However, the surgical outcomes of this approach compared with that of single-level decompression remain unknown. MATERIALS AND METHODS: The data of patients with spinal surgery for pure cervical radiculopathy were collected. Patients were categorized into the single-level (SLDG) or multilevel (MLDG) intervertebral decompression group at C3/C4/C5/C6/C7/T1. Demographic data and patient-reported outcome scores, including the Neck Disability Index (NDI) and Numerical Rating Scale (NRS) scores for pain and numbness in the neck, upper back, and arms, were collected. The NDI improvement rates and changes in NRS scores were analyzed one year postoperatively at patient-reported outcome evaluation. Propensity score matching was performed to compare both groups after adjusting for baseline characteristics, including the preoperative NDI and NRS scores. RESULTS: Among the 357 patients in this study, SLDG and MLDG comprised 231 and 126 patients, respectively. Two groups (n=112, each) were created by propensity score matching. Compared with the MLDG, the SLDG had a higher postoperative NDI improvement rate ( P =0.029) and lower postoperative arm numbness NRS score ( P =0.037). Other outcomes tended to be more favorable in the SLDG than in the MLDG, yet no statistical significance was detected. CONCLUSIONS: In patients with cervical radiculopathy, the surgical outcomes of the SLDG showed better improvement in clinical outcomes than those of the MLDG. Numbness remained on the distal (arms) rather than the central (neck and upper back) areas in patients receiving multilevel decompression.

Limitations of minimally invasive posterior cervical foraminotomy-a decompression method of posteriorly shifting the nerve root-in cases of large anterior osteophytes in cervical radiculopathy: A retrospective multicenter cohort study.

BACKGROUND: Posterior cervical foraminotomy against anterior osteophyte is an indirect decompression procedure but less invasive compared to anterior cervical discectomy and fusion. Residual compression to the nerve root may lead to poor surgical outcomes. Although clinical results of posterior cervical foraminotomy for osteophytes are not considered better than those of disk herniation, osteophyte size and the association of the decompression area with poor surgical outcomes remain unclear. This study aimed to identify the limitations of minimally invasive posterior cervical foraminotomy for cervical radiculopathy and discuss the methods to improve surgical outcomes. METHODS: We analyzed 55 consecutive patients with degenerative cervical radiculopathy who underwent minimally invasive posterior cervical foraminotomy. Minimum postoperative follow-up duration was 1 year. We divided the patients into nonimproved and improved groups. The cutoff value between preoperative and postoperative Neck Disability Index scores was 30% improvement. Preoperative imaging data comprised disk height, local kyphosis, spinal cord compression, anterior osteophytes in the foramen, and anterior osteophytes of >50% of the intervertebral foramen diameter. Postoperative imaging data comprised craniocaudal length and lateral width of decompressed lamina, preserved superior facet width, and area of decompressed lamina. RESULTS: Fifty-five patients were divided into two groups: nonimproved (n = 19) and improved (n = 36). The presence of osteophytes itself was not significant; however, the presence of osteophytes of >50% of the foramen diameter increased in the nonimproved group (P = 0.004). Mean lateral width and mean area of decompressed lamina after surgery significantly increased in the improved group (P = 0.001, P = 0.03). CONCLUSION: The presence of anterior osteophytes >50% of the diameter of the foramen led to poor improvement of clinical outcomes in minimally invasive posterior cervical foraminotomy. However, the larger the lateral width and area of the decompressed lamina, the better the surgical outcome.

Comparison of the Outcomes of Microendoscopic Discectomy Versus Full-Endoscopic Discectomy for the Treatment of L4/5 Lumbar Disc Herniation.

STUDY DESIGN: Retrospective Comparative Study. OBJECTIVES: To compare the outcomes of microendoscopic discectomy (MED) versus full-endoscopic discectomy (FED) for treating L4/5 lumbar disc herniation (LDH). METHODS: A retrospective study was performed on patients with L4/5 LDH treated using MED (n = 249) or FED (n = 124). A 16-mm tubular retractor and endoscope was used for MED, while a 4.1-mm working channel endoscope was used for FED. Patient background and operative data were collected. The Oswestry Disability Index (ODI) and European Quality of Life-5 Dimensions (EQ-5D) scores were recorded preoperatively and at 1 and 2 years postsurgery. RESULTS: The background data of the two groups were similar. The mean operation times for MED and FED were 59.3 and 47.7 min (respectively), and the mean volumes of removed nucleus pulposus were .65 and 1.03 g, respectively. These differences were significant (P < .001). Six dural tears and one postoperative hematoma were observed in the MED group; none were observed in the FED group. During the follow-up period, 16 MED and 7 FED patients required re-operation due to recurrence (P = 1.00). Although the ODI and EQ-5D scores significantly improved at 1 and 2 years postsurgery in both groups, the differences were not statistically significant. CONCLUSIONS: Operative outcomes were almost identical in both groups. We did not observe any operative or postoperative complications in FED. We, therefore, recommend FED as the first option for the treatment of L4/5 LDH since it has a better safety profile and is minimally invasive.

Comparison of Outcomes of Lumbar Interbody Fusion and Full-endoscopic Laminectomy for L5 Radiculopathy Caused by Lumbar Foraminal Stenosis.

This study compared the outcomes of microendoscopy-assisted lumbar interbody fusion (ME-LIF) and uniportal full-endoscopic laminectomy (FEL) for L5 radiculopathy caused by lumbar foraminal stenosis (LFS). ME-LIF was performed using an 18- to 20-mm tubular retractor and endoscope, and FEL via the translaminar approach (TLA) was performed at the dorsal part of the foramen using a 4.1-mm working channel endoscope. Patients with LFS treated using ME-LIF (n = 39) or FEL-TLA (n = 30) were retrospectively evaluated. Patients' background and operative data were collected. The 36-item Short Form Survey (SF-36), Oswestry Disability Index (ODI), and European Quality of Life-5 Dimension (EQ-5D) scores were recorded preoperatively and 2 years postoperatively. The background data of the two groups (ME-LIF and FEL-TLA) were similar. The mean operation times for ME-LIF and FEL-TLA were 110.7 and 65.2 min, respectively, and the mean length of hospital stay were 10.3 and 1.5 days, respectively. Reoperation was required for surgical site infection, and percutaneous pedicle screw malposition in three patients was treated using ME-LIF. During follow-up, second FEL-TLA and LIF were performed for recurrent L5 radiculopathy in one and three patients in the FEL-TLA group, respectively. Although the SF-36, ODI, and EQ-5D scores 2 years postoperatively improved in both groups, improvement in ODI scores was lower following FEL-TLA than following ME-LIF. FEL-TLA can be performed to treat patients with L5 radiculopathy caused by LFS. Although the ODI score improvement following FEL-TLA was unremarkable, FEL-TLA might be considered because of its better safety profile and minimal invasiveness than ME-LIF.

Influence of Perioperative Antithrombic Agent Discontinuation in Elective Posterior Spinal Surgery: A Propensity-Score-Matched Analysis.

OBJECTIVE: To investigate the influence of perioperative antithrombotic agent (antiplatelet agents and anticoagulants) discontinuation in elective posterior spinal surgery in terms of bleeding complications, such as epidural hematoma and postoperative thromboembolism. METHODS: We enrolled patients undergoing elective posterior spinal surgery at 9 hospitals between April 2017 and August 2020. We collected data regarding patient baseline characteristics, surgical details, intraoperative estimated blood loss, and postoperative complication rates, including epidural hematoma and thromboembolism. We divided the patients into a discontinuation group, in which antithrombic agents were discontinued perioperatively, and a control group without antithrombic agents. Propensity scores for taking any antithrombic agents were calculated, with 1-to-1 matching based on the estimated propensity scores to adjust for patient baseline characteristics and surgical details. Intraoperative estimated blood loss and 30-day postoperative complication rates were compared between the groups. RESULTS: We enrolled 9853 patients, including 1123 patients (11.4%) who discontinued antithrombic agents perioperatively. One-to-one propensity score matching yielded 1111 pairs with and without antithrombic agents. Intraoperative estimated blood loss per 10 minutes (8.2 mL vs. 8.9 mL) and the incidence of epidural hematoma requiring revision (0.97% vs. 0.72%) were similar between the groups. Although postoperative cardiac events and stroke were observed only in the discontinuation group (0.27% and 0.09%, respectively), these incidences were not significantly different between the groups. CONCLUSIONS: Perioperative antithrombic agent discontinuation in elective posterior spinal surgery normalized the intraoperative bleeding tendency and the incidence of postoperative epidural hematoma and did not influence in a significative way the incidence of postoperative thromboembolism.

Comparison between microendoscopic laminectomy and open posterior decompression surgery for single-level lumbar spinal stenosis: a multicenter retrospective cohort study.

BACKGROUND: Microendoscopic laminectomy (MEL), in which a 16-mm tubular retractor with an internal scope is used, has shown excellent surgical results for patients with lumbar spinal canal stenosis. However, no reports have directly compared MEL with open laminectomy. This study aimed to elucidate patient-reported outcomes (PROs) and perioperative complications in patients undergoing MEL versus open laminectomy. METHODS: This is a multicenter retrospective cohort study of prospectively registered patients who underwent lumbar spinal surgery at one of the six high-volume spine centers between April 2017 and September 2018. A total of 258 patients who underwent single posterior lumbar decompression at L4/L5 were enrolled in the study. With regard to demographic data, we prospectively used chart sheets to evaluate the diagnosis, operative procedure, operation time, estimated blood loss, and complications. The follow-up period was 1-year. PROs included a numerical rating scale (NRS) for lower back pain and leg pain, the Oswestry Disability Index (ODI), EuroQol 5 Dimension (EQ-5D), and patient satisfaction with the treatment. RESULTS: Of the 258 patients enrolled, 252 (97%) completed the 1-year follow-up. Of the 252, 130 underwent MEL (MEL group) and 122 underwent open decompression (open group). The MEL group required a significantly shorter operating time and sustained lesser intraoperative blood loss compared with the open group. The MEL group showed shorter length of postoperative hospitalization than the open group. The overall complication rate was similar (8.2% in the MEL group versus 7.7% in the open group), and the revision rate did not significantly differ. As for PROs, both preoperative and postoperative values did not significantly differ between the two groups. However, the satisfaction rate was higher in the MEL group (74%) than in the open group (53%) (p = 0.02). CONCLUSIONS: MEL required a significantly shorter operating time and resulted in lesser intraoperative blood loss compared with laminectomy. Postoperative PROs and complication rates were not significantly different between the procedures, although MEL demonstrated a better satisfaction rate.

One-year clinical outcome after full-endoscopic interlaminar lumbar discectomy for isthmic lumbar spondylolisthesis: Two case reports.

RATIONALE: For isthmic lumbar spondylolisthesis (ILS) associated with the removal of herniation, it remains challenging to perform less invasive and minimally disruptive procedures. Good results could potentially be obtained by further preserving the posterior elements in full-endoscopic lumbar discectomy (FESS), which is less invasive than microenscopic surgery (MES). PATIENT CONCERNS: One patient complained of left leg pain, and another patient complained of right leg pain and low back pain. DIAGNOSES: Two patients with ILS and Meyerding Grade 1 lumbar spondylolisthesis. INTERVENTIONS: We performed a full-endoscopic lumbar discectomy via the interlaminar space (FESS-IL) for L5/S1 lumbar disc herniation (LDH) accompanied by isthmic lumbar spondylolisthesis. FESS-IL was performed in 2 patients with radiculopathy caused by different types of LDH using a full endoscopic system with a 4.1 mm working channel and 6.9 mm outer diameter. A 3.5-mm diameter high-speed drill was used in one patient for an upward-migrated LDH in the inner-rim of the infravertebral border. The other patient underwent minimal resection without bone resection. OUTCOMES: The one-year clinical outcome included confirmation of pain relief and evacuation of migrated LDH on magnetic resonance imaging in all patients. There was no progression of slippage on radiography. The mean operative time was 82 min, and no complication was observed. The one-year clinical outcome demonstrated sufficient pain relief. LESSONS THE Y: ear postoperative outcome showed improvement. We believe that FESS-IL is a viable alternative operative approach for LDH for ILS.

Risk factors for deep surgical site infection after posterior cervical spine surgery in adults: a multicentre observational cohort study.

Surgical site infection (SSI) is a serious complication following spine surgery and is correlated with significant morbidities, poor clinical outcomes, and increased healthcare costs. Accurately identifying risk factors can help develop strategies to reduce this devastating consequence; however, few multicentre studies have investigated risk factors for SSI following posterior cervical spine surgeries. Between July 2010 and June 2015, we performed an observational cohort study on deep SSI in adult patients who underwent posterior cervical spine surgery at 10 research hospitals. Detailed patient- and procedure-specific potential risk variables were prospectively recorded using a standardised data collection chart and were reviewed retrospectively. Among the 2184 consecutive adult patients enrolled, 28 (1.3%) developed postoperative deep SSI. Multivariable regression analysis revealed 2 statistically significant independent risk factors: occipitocervical surgery (P < 0.001) and male sex (P = 0.024). Subgroup analysis demonstrated that occipitocervical surgery (P = 0.001) was the sole independent risk factor for deep SSI in patients with instrumented fusion. Occipitocervical surgery is a relatively rare procedure; therefore, our findings were based on a large cohort acquired using a multicentre study. To the best of our knowledge, this is the first study to identify occipitocervical procedure as an independent risk variable for deep SSI after spinal surgery.

Microendoscope-Assisted Versus Open Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease: A Multicenter Retrospective Cohort Study.

Background and objectives: Minimally invasive surgery has become popular for posterior lumbar interbody fusion (PLIF). Microendoscope-assisted PLIF (ME-PLIF) utilizes a microendoscope within a tubular retractor for PLIF procedures; however, there are no published reports that compare Microendoscope-assisted to open PLIF. Here we compare the surgical and clinical outcomes of ME-PLIF with those of open PLIF. Materials and Methods: A total of 155 consecutive patients who underwent single-level PLIF were registered prospectively. Of the 149 patients with a complete set of preoperative data, 72 patients underwent ME-PLIF (ME-group), and 77 underwent open PLIF (open-group). Clinical and radiographic findings collected one year after surgery were compared. Results: Of the 149 patients, 57 patients in ME-group and 58 patients in the open-group were available. The ME-PLIF procedure required a significantly shorter operating time and involved less intraoperative blood loss. Three patients in both groups reported dural tears as intraoperative complications. Three patients in ME-group experienced postoperative complications, compared to two patients in the open-group. The fusion rate in ME-group at one year was lower than that in the open group (p = 0.06). The proportion of patients who were satisfied was significantly higher in the ME-group (p = 0.02). Conclusions: ME-PLIF was associated with equivalent post-surgical outcomes and significantly higher rates of patient satisfaction than the traditional open PLIF procedure. However, the fusion rate after ME-PLIF tended to be lower than that after the traditional open method.

Clinical Evaluation of Microendoscopy-Assisted Oblique Lateral Interbody Fusion.

Background and objectives: Oblique Lateral Interbody Fusion (OLIF) is a widely performed, minimally invasive technique to achieve lumbar lateral interbody fusion. However, some complications can arise due to constraints posed by the limited surgical space and visual field. The purpose of this study was to assess the short-term postoperative clinical outcomes of microendoscopy-assisted OLIF (ME-OLIF) compared to conventional OLIF. Materials and Methods: We retrospectively investigated 75 consecutive patients who underwent OLIF or ME-OLIF. The age, sex, diagnosis, and number of fused levels were obtained from medical records. Operation time, estimated blood loss (EBL), and intraoperative complications were also collected. Operation time and EBL were only measured per level required for the lateral procedure, excluding the posterior fixation surgery. The primary outcome measure was assessed using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ). The secondary outcome measure was assessed using the Oswestry Disability Index (ODI) and the European Quality of Life-5 Dimensions (EQ-5D), measured preoperatively and 1-year postoperatively. Results: This case series consisted of 14 patients in the OLIF group and 61 patients in the ME-OLIF group. There was no significant difference between the two groups in terms of the mean operative time and EBL (p = 0.90 and p = 0.50, respectively). The perioperative complication rate was 21.4% in the OLIF group and 21.3% in the ME-OLIF group (p = 0.99). In both groups, the postoperative JOABPEQ, EQ-5D, and ODI scores improved significantly (p < 0.001). Conclusions: Although there was no significant difference in clinical results between the two surgical methods, the results suggest that both are safe surgical methods and that microendoscopy-assisted OLIF could serve as a potential alternative to the conventional OLIF procedure.

Risk factors for deep surgical site infection following posterior instrumented fusion for degenerative diseases in the thoracic and/or lumbar spine: a multicenter, observational cohort study of 2913 consecutive cases.

PURPOSE: Surgical site infection (SSI) is one of the most devastating complications following spinal instrumented fusion surgeries because it may lead to a significant increase in morbidity, mortality, and poor clinical outcomes. Identifying the risk factors for SSI can help in developing strategies to reduce its occurrence. However, data on the risk factors for SSI in degenerative diseases are limited. This study aimed to identify risk factors for deep SSI following posterior instrumented fusion for degenerative diseases in the thoracic and/or lumbar spine in adult patients. METHODS: This was a multicenter, observational cohort study conducted at 10 study hospitals between July 2010 and June 2015. The subjects were consecutive adult patients who underwent posterior instrumented fusion surgery for degenerative diseases in the thoracic and/or lumbar spine and developed SSI. Detailed patient-specific and procedure-specific potential risk variables were prospectively recorded using a standardized data collection chart and retrospectively reviewed. RESULTS: Of the 2913 enrolled patients, 35 developed postoperative deep SSI (1.2%). Multivariable regression analysis identified three independent risk factors: male sex (P = 0.002) and American Society of Anesthesiologists (ASA) score of ≥ 3 (P = 0.003) as patient-specific risk factors, and operation including the thoracic spine (P = 0.018) as a procedure-specific risk factor. CONCLUSION: Thoracic spinal surgery, an ASA score of ≥ 3, and male sex were risk factors for deep SSI after routine thoracolumbar instrumented fusion surgeries for degenerative diseases. Awareness of these risk factors can enable surgeons to develop a more appropriate management plan and provide better patient counseling.

Partial Resection of Spinous Process for the Elderly Patients with Thoraco-Lumbar Kyphosis: Technical Report.

Background and objectives: Global sagittal imbalance with lumbar hypo-lordosis can cause low back pain (LBP) during standing and/or walking. This condition has recently been well-known as one of the major causes of reduced health-related quality of life (HRQOL) in elderly populations. Decrease in disc space of anterior elements and an increase in the spinous process height of posterior elements may both contribute to the decrease in lordosis of the lumbar spine. To correct the sagittal imbalance, the mainstream option is still a highly invasive surgery, such as long-segment fusion with posterior wedge osteotomy. Therefore, we developed a treatment that is partial resection of several spinous processes of thoraco-lumbar spine (PRSP) and lumbar extension exercise to improve the flexibility of the spine as postoperative rehabilitation. Materials and Methods: Consecutively, seven patients with over 60 mm of sagittal vertical axis (SVA) underwent PRSP. The operation was performed with several small midline skin incisions under general anesthesia. After splitting the supraspinous ligaments, the cranial or caudal tip of the spinous process of several thoraco-lumbar spines was removed, and postoperative rehabilitation was followed to improve extension flexibility. Results: The average follow-up period was 13.0 months. The average blood loss and operation time were 11.4 mL and 47.4 min, respectively. The mean SVA improved from 119 to 93 mm but deteriorated in one case. The mean numerical rating scale of low back pain improved from 6.6 to 3.7 without any exacerbations. The mean Oswestry Disability Index score was improved from 32.4% to 19.1% in six cases, with one worsened case. Conclusions: We performed PRSP and lumbar extension exercise for the patients with LBP due to lumbar kyphosis. This minimally invasive treatment was considered to be effective in improving the symptoms of low back pain and HRQOL, especially of elderly patients with lumbar kyphosis.