Biportal endoscopy-assisted lateral mass screw fixation using a third portal.

BACKGROUND: The technique of spinal decompression under endoscopy has been widely applied, but reports on endoscopic cervical fixation are rare. The unilateral biportal endoscopic (UBE) technique stands out for its lesser muscle intrusion and more flexible surgical approach. METHOD: We applied the UBE approach for cervical fixation and laminectomy. We achieved bilateral lateral mass screw fixation by making an auxiliary UBE portal combined with the Roy-Camille and Magerl techniques. CONCLUSIONS: Our successful implementation of cervical fixation using the UBE technique at the C3/4 level suggests its efficacy. This approach is a valuable and minimally invasive option for cervical fixation.

Short-term lumbar disc and lumbar stability changes of one-hole split endoscope technique treatment of spinal stenosis.

OBJECTIVE: Investigating the early biomechanical effects of the one-hole split endoscope (OSE) technique on lumbar spine after decompression surgery. METHODS: A retrospective analysis was conducted on 66 patients with lumbar spinal stenosis (LSS) who underwent OSE technique surgery at the affiliated hospital of Binzhou Medical University from September 2021 to September 2022. The patients had complete postoperative follow-up records. The mean age was (51.73 ± 12.42) years, including 33 males and 33 females. The preoperative and postoperative imaging data were analyzed, including disc height (DH), foraminal height (FH), lumbar lordosis angle (LLA), changes in disc angle, anterior-posterior translation distance, and lumbar intervertebral disc Pfirrmann grading. The visual analogue scale (VAS) was applied to evaluate the severity of preoperative, postoperative day 1, postoperative 3 months, and final follow-up for back and leg pain. The Oswestry Disability Index (ODI) was applied to assess the functionality at all the listed time points. The modified MacNab criteria were applied to evaluate the clinical efficacy at the final follow-up. RESULTS: In 66 patients, there were statistically significant differences (p < 0.05) in DH and FH at the affected segments compared to preoperative values, whereas no significant differences (p > 0.05) were found in DH and FH at the adjacent upper segments compared to preoperative values. There was no statistically significant difference in the LLA compared to preoperative values (p > 0.05). Both the affected segments and adjacent upper segments showed statistically significant differences in Pfirrmann grading compared to preoperative values (p < 0.05). There were no statistically significant differences in the changes in disc angle or anterior-posterior translation distance in the affected or adjacent segments compared to preoperative values (p > 0.05). The VAS scores for back and leg pain, as well as the ODI, significantly improved at all postoperative time points compared to preoperative values. Among the comparisons at different time points, the differences were statistically significant (p < 0.05). The clinical efficacy was evaluated at the final follow-up using the modified MacNab criteria, with 51 cases rated as excellent, 8 cases as good, and 7 cases as fair, resulting in an excellent-good rate of 89.39%. CONCLUSIONS: The OSE technique, as a surgical option for decompression in the treatment of LSS, has no significant impact on lumbar spine stability in the early postoperative period. However, it does have some effects on the lumbar intervertebral discs, which may lead to a certain degree of degeneration.

Which devices can be used to decompress odontogenic cystic lesions in the oral cavity? A systematic review.

Odontogenic cysts are bony lesions in the jaws that can reach large sizes. Decompression, a technique that helps in their surgical treatment, aims to reduce their size. We aimed to conduct a systematic review of the main types of device used for the decompression of odontogenic cysts and to analyse the indications, types, advantages, and disadvantages of the devices used. We searched PubMed, Science Direct, LILACS, EMBASE, and Web of Science until February 2023, with no time restriction. We considered studies with a minimum of 10 patients published only in English, those that reported cases and case series, randomised clinical trials of the decompression of odontogenic cysts, and the types of devices used during the decompression period. All reported odontogenic cysts had to have been confirmed by biopsy in their respective publications. We found 713 articles in the selected databases. After removing duplicates, 499 remained. After reading the titles and abstracts, we excluded 461 articles so 38 remained. Nine studies were selected for the review, totalling 244 patients. A total of 206 lesions were identified and confirmed by anatomopathological examination: 123 keratocysts, 40 dentigerous cysts, 34 radicular cysts, one cyst of epithelial origin but without specification, and eight unicystic ameloblastomas. Although we did not find out which device is best for the decompression of odontogenic cysts, our findings show that those that are most effective should be as comfortable as possible and should remain in place. They should have stability in the oral cavity and be easy for the patient to clean.

Three-dimensional analysis of puncture needle path through safety triangle approach PLD and design of puncture positioning guide plate.

OBJECTIVE: In this study, the three-dimensional relationship between the optimal puncture needle path and the lumbar spinous process was discussed using digital technology. Additionally, the positioning guide plate was designed and 3D printed in order to simulate the surgical puncture of specimens. This plate served as an important reference for the preoperative simulation and clinical application of percutaneous laser decompression (PLD). METHOD: The CT data were imported into the Mimics program, the 3D model was rebuilt, the ideal puncture line N and the associated central axis M were developed, and the required data were measured. All of these steps were completed. A total of five adult specimens were chosen for CT scanning; the data were imported into the Mimics program; positioning guide plates were generated and 3D printed; a simulated surgical puncture of the specimens was carried out; an X-ray inspection was carried out; and an analysis of the puncture accuracy was carried out. RESULTS: (1) The angle between line N and line M was 42°~55°, and the angles between the line M and 3D plane were 1°~2°, 5°~12°, and 78°~84°, respectively; (2) As the level of the lumbar intervertebral disc decreases, the distance from point to line and point to surface changes regularly; (3) The positioning guide was designed with the end of the lumbar spinous process and the posterior superior iliac spine on both sides as supporting points. (4) Five specimens were punctured 40 times by using the guide to simulate surgical puncture, and the success rate was 97.5%. CONCLUSION: By analyzing the three-dimensional relationship between the optimal puncture needle path and the lumbar spinous process, the guide plate was designed to simulate surgical puncture, and the individualized safety positioning of percutaneous puncture was obtained.

The Ultrasonic Bone Scalpel does not Outperform the High-Speed Drill: A Single Academic Experience.

BACKGROUND: Spinal decompression and osteotomies are conventionally performed using high-speed drills (HSDs) and rongeurs. The ultrasonic bone scalpel (UBS) is a tissue-specific osteotome that preferentially cuts bone while sparing the surrounding soft tissues. There is ongoing investigation into its ability to optimize peri- and postoperative outcomes in spine surgery. The purpose of this study was to compare the intraoperative metrics and complications during a transition period from HSD to UBS. METHODS: A single-institution, single-surgeon retrospective analysis was conducted of patients undergoing spine surgery from January 2020 to December 2021. Statistical analyses were performed to detect associations between the surgical technique and outcomes of interest. A P value < 0.05 was considered statistically significant. RESULTS: A total of 193 patients met the inclusion criteria (HSD, n = 100; UBS, n = 93). Multivariate logistic regression revealed similar durotomy (P = 0.10), nerve injury (P = 0.20), and reoperation (P = 0.68) rates. Although the estimated blood loss (EBL) and length of stay were similar, the operative time was significantly longer with the UBS (192.81 vs. 204.72 minutes; P = 0.03). Each subsequent surgery using the UBS revealed a 3.1% decrease in the probability of nerve injury (P = 0.026) but had no significant effects on the operative time, EBL, or probability of durotomy or reoperation. CONCLUSIONS: The UBS achieves outcomes on par with conventional tools, with a trend toward a lower incidence of neurologic injury. The expected reductions in EBL and durotomy were not realized in our cohort, perhaps because of a high proportion of revision surgeries, although these might be dependent on surgeon familiarity, among other operative factors. Future prospective studies are needed to validate our results and further refine the optimal application of this device in spine surgery.

Short- and long-term outcomes of a self-expandable metallic stent versus a transanal decompression tube for pathological stage II and III left-sided obstructive colorectal cancer: a retrospective observational study.

PURPOSE: Few studies have investigated the long-term oncological outcomes of the self-expandable metallic stent (SEMS) as a bridge to surgery (BTS) for obstructive colorectal cancer (OCRC). We conducted this study to compare the short- and long-term outcomes of the SEMS with those of the traditional transanal decompression tube (TDT) in patients with stage II and III left-sided OCRC. METHODS: The subjects of this retrospective study were 78 patients with pathological stage II and III left-sided OCRC who underwent radical surgery after SEMS or TDT placement, between April, 2005 and September, 2019. We compared perioperative data, including decompression success rates and 3-year relapse-free survival (RFS), between the SEMS and TDT groups. RESULTS: A SEMS was placed in 60 (76.9%) patients and a TDT was placed in 18 (23.1%) patients, achieving a clinical success rate of decompression of 98.3% in the SEMS group and 77.8% in the TDT group (P = 0.009). The 3-year RFS of the overall cohort was better in the SEMS group than in the TDT group (74.9% vs. 40.9%, respectively; P = 0.003). CONCLUSIONS: Decompression using a SEMS as the BTS may improve oncological outcomes over those achieved by a TDT in patients with left-sided stage II and III OCRC.

Motor Bur Milling State Identification via Fast Fourier Transform Analyzing Sound Signal in Cervical Spine Posterior Decompression Surgery.

OBJECTIVES: To investigate the real-time sensitive feedback parameter of the motor bur milling state in cervical spine posterior decompression surgery, to possibly improve the safety of cervical spine posterior decompression and robot-assisted spinal surgeries. METHODS: In this study, the cervical spine of three healthy male and three healthy female pigs were randomly selected. Six porcine cervical spine specimens were fixed to the vibration isolation system. The milling state of the motor bur was defined as the lamina cancellous bone (CA), lamina ventral corticalbone (VCO), and penetrating ventral cortical bone (PVCO). A 5-mm bur milled the CA and VCO, and a 2-mm bur milled the VCO and PVCO. A miniature microphone was used to collect the sound signal (SS) of milling lamina which was then extracted using Fast Fourier Transform (FFT). When using 5-mm and 2-mm bur to mill, the CA, VCO, and PVCO of each specimen were continuously collected at 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 kHz frequencies for SS magnitudes. The study randomly selected the SS magnitudes of the CA and VCO continuously for 2 s at 1, 2, 3, 4, and 5 kHz frequencies for statistical analyses. When milling the VCO to the PVCO, we randomly collected the SS magnitudes of the VCO for consecutive 2 s and the SS magnitudes of continuous 2 s in the penetrating state at 1, 2, 3, 4, and 5 kHz frequencies for statistical analyses. The independent sample t-test was used to compare the SS magnitudes of different milling states extracted from the FFT to determine the motor bur milling state. RESULTS: The SS magnitudes of the CA and VCO of all specimens extracted from the FFT at 1, 2, and 3 kHz were statistically different (P < 0.01); three specimens were not statistically different at a specific FFT-extracted frequency (first specimen at 5 kHz, SS magnitudes of the CA were [25.94 ± 8.74] × 10-3 , SS magnitudes of the VCO were [28.67 ± 12.94] × 10-3 , P = 0.440; second specimen at 4 kHz, SS magnitudes of the CA were [23.79 ± 7.94] × 10-3 , SS magnitudes of the VCO were [24.78 ± 4.32] × 10-3 , P = 0.629; and third specimen at 5 kHz, SS magnitudes of the CA were [16.76 ± 6.20] × 10-3 , SS magnitudes of the VCO were [17.69 ± 6.44] × 10-3 , P = 0.643).The SS magnitudes of the VCO and PVCO of all the specimens extracted from the FFT at each frequency were statistically different (P < 0.001). CONCLUSIONS: Based on the FFT extraction, the SS magnitudes of the motor bur milling state between the CA and VCO, the VCO and PVCO were significantly different, confirming that the SS is a potential sensitive feedback parameter for identifying the motor bur milling state. This study could improve the safety of cervical spine posterior decompression surgery, especially of robot-assisted surgeries.

A Minimally Invasive Full Endoscopic Approach to Tibial Nerve Neurolysis in Diabetic Foot Neuropathy: An Alternative to Open Procedures.

BACKGROUND: Dellon et al. have reported that chronic nerve compression of the tibial nerve inside the tarsal tunnel, caused by diabetes mellitus, can be relieved following open decompression surgery. However, the large skin incision resulting from Dellon's procedure may cause wound healing problems. The authors report the possibility of a minimally invasive full endoscopic procedure. METHODS: Operations were performed under local anesthesia without a pneumatic tourniquet. An anesthetic agent was applied at the proximal part of the flexor retinaculum of the foot, and a hypodermic needle was advanced into the tarsal tunnel. Tarsal tunnel pressure and blood circulation of the tibial nerve using indocyanine green assessment were measured preoperatively. One 1-cm portal skin incision was made at the anesthetized area and the Universal Subcutaneous Endoscope system was inserted into the tarsal tunnel. The flexor retinaculum, tibial nerve, blood vessels, and abductor hallucis muscle fascia were identified under endoscopic observation. After decompression of the tarsal tunnel, the authors measured tarsal tunnel pressure and blood circulation of the tibial nerve for analysis of the effectiveness of the endoscopic decompression during the procedure. RESULTS: Fourteen operations were compiled and analyzed. Postoperative clinical status was improved based on the preoperative modified Toronto Clinical Neuropathy Score. The mean tarsal tunnel pressure dropped to 4.5 mmHg during surgery from the initial preoperative 49.4 mmHg in resting position. Endoscopic indocyanine green assessment showed more than 30 percent improvement of the vascularity surrounding the tibial nerve. CONCLUSION: The authors' minimally invasive full endoscopic procedure is a viable alternative approach for tarsal tunnel syndrome patients with diabetic foot neuropathy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Cement-Augmented and Dual-Headed Posterior Screw Reconstruction After Corpectomy for Metastatic Tumor Resection.

BACKGROUND: Metastatic spinal tumors have a well-documented deleterious effect on the overall strength of the bony spine. Surgical interventions must address not only removal of the tumor itself, but the integrity of reconstructive hardware constructs as well. METHODS: We present a series of 8 patients with metastatic spine tumors who were successfully treated with tumor resection and reconstruction of residual 3-column defect with cement-augmented fenestrated pedicle screws and dual-rod posterior stabilization. RESULTS: All patients demonstrated resolution of their presenting neurologic symptoms. CONCLUSIONS: This series supports the use of the aforementioned constructs in conjunction to provide added stability and reduce hardware failure when treating a diversity of spinal tumors.

Autologous stem cell implantation with core decompression for avascular necrosis of the femoral head using a new device.

INTRODUCTION: Autologous stem cell progenitor implantation into necrotic lesions of the femoral head has previously been described as a potential treatment for avascular necrosis (AVN), on the basis that there is a reduced number of functioning stem cells in the marrow within the necrotic segment. We present a case series of patients with AVN that underwent core decompression with autologous stem cell implantation using a new device. METHODS: The records and imaging of patients with AVN of the femoral head treated by a single surgeon were retrospectively reviewed. All patients were treated with core decompression and stem cell progenitor implantation, using the PerFuse system. Preoperatively, demographic information, AVN staging (as per Ficat and Arlet classification) and visual analogue pain scores (VAS) of the hips were recorded. These results were compared with postoperative VAS and imaging, with further review on the progression of AVN. RESULTS: We treated 14 hips in 13 patients with an average follow up of 12 months. Patients with Ficat I-II were selected for the procedure. The average preoperative VAS was 3.9. Postoperatively, this dropped to 2.6, with over half of patients reporting at least a two-point decrease in pain. Eight of the 14 treated hips showed no radiological progression of the disease, while six showed femoral head collapse requiring total hip arthroplasty (THA) at an average of ten months after treatment. CONCLUSION: Our early findings indicate that hip decompression with stem cell progenitor implantation for AVN of the femoral head provides symptomatic relief and may be beneficial in arresting progression of disease using this simple new device.

Development and evolution of a robotic surgical technique for the treatment of thoracic outlet syndrome.

OBJECTIVE: We describe the development and evolution of a surgical technique that uses the robotic da Vinci Surgical System (Intuitive Surgical, Inc, Sunnyvale, Calif) for the transaxillary approach to repair the disabling thoracic outlet syndrome (TOS). We report our patient outcomes associated with the use of this robotic technique. METHODS: We present a retrospective review and analysis of data collected from a 16-year experience of a single surgeon using a robotic surgical system and technique for TOS surgery. From the initial design of an endoscope attached to a microvideo camera in 1982 to the adoption of the monorobotic arm with integrated voice in 1998, the main objective of the transaxillary approach has always been to improve visualization of congenital cervical anomalies of the scalene muscles. From February 2003 to December 2018, we performed 412 transaxillary decompression procedures using the robotic da Vinci Surgical System. The surgical procedure has been described in further detail and includes the following steps: (1) positioning of the patient into a lateral decubitus position and using a monoarm retractor; (2) creation of a mini-incision in the axillary area and creation and maintenance of the subpectoral anatomic working space; (3) placement of endoscopic ports and engagement of the robotic instrumentation; (4) dissection of extrapleural and intrapleural soft tissue; (5) creation of the "floater" first rib; (6) excision of the cervical bands and first rib; and (7) placement of thoracostomy tubes for drainage and closure of the incisions. RESULTS: None of the patients died, and no patient experienced permanent neurovascular damage of the extremity. Of the 306 patients, 22 (5% of 441 operations) experienced complications. One patient developed postoperative scarring that required a redo operation with a robotic-assisted transaxillary approach. CONCLUSIONS: With its three-dimensional visual magnification of the anatomic area, the endoscopic robotic-assisted transaxillary approach offers safe and effective management of disabling TOS symptoms. The endoscope facilitates observation of the cervical bands and the mechanism (pathogenesis) of the neurovascular compression that causes TOS, thereby allowing complete excision of the first rib, cervical bands, and scalene muscle. We sought to develop and perfect this robotic approach. The present study was not intended to be a comparative study to nonrobotic TOS surgery.

Percutaneous Endoscopic Unilateral Laminotomy and Bilateral Decompression for Lumbar Spinal Stenosis.

To introduce a new surgery, percutaneous endoscopic unilateral laminotomy and bilateral decompression (Endo-ULBD) using visual trepan, and investigate its efficacy and safety in elderly patients with lumbar spinal stenosis. In our retrospective study, a total of 69 patients were enrolled between March 2018 and September 2018; 31 patients were treated with Endo-ULBD and 38 patients were treated with posterior lumbar interbody fusion surgery (PLIF). The operation time, intraoperative blood loss, and hospitalization duration were compared between the two groups. A visual analog scale (VAS) was used to evaluate the degree of pain. The Oswestry Disability Index (ODI) and European Quality of Life-5 Dimensions (EQ-5D) were used to evaluate lumbar function and quality of life, respectively. Lumbar X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) were performed postoperatively at different time points. MacNab's outcome assessment and perioperative complications were also documented. The surgeon completed all surgeries successfully, and all 69 patients were followed up. The operative time of the Endo-ULBD group was 60.68 ± 0.47 min, while that of the PLIF group was 120.23 ± 10.24 min. The operative time of the Endo-ULBD group was shorter than that of the PLIF group, and the difference was statistically significant (P < 0.001). The volume of intraoperative blood loss was 47.25 ± 0.43 mL in the Endo-ULBD group and 256.90 ± 20.83 mL in the PILF group (P < 0.001). The length of hospital stay in the Endo-ULBD group was 5.12 ± 1.60 days and that in the PILF group was 10.54 ± 1.82 days (P < 0.001). The VAS scores at postoperative 1 day, 3 months, 6 months, final follow-up (Endo-ULBD: 6.58 ± 0.65, 4.55 ± 0.54, 2.78 ± 0.24, 1.31 ± 0.78; PLIF: 7.19 ± 1.14, 4.80 ± 0.13, 2.71 ± 0.83, 1.29 ± 0.56) were significantly improved compared with those before surgery (Endo-ULBD: 8.63 ± 0.37; PLIF: 8.31 ± 1.34). The ODI and EQ-5D scores of lumbar function and quality of life at each time point after surgery (Endo-ULBD ODI: 30.29% ± 0.47%, 23.35% ± 0.95%, 19.45% ± 0.81%, 10.84% ± 0.36%; EQ-5D: 0.38 ± 0.15, 0.45 ± 0.17, 0.63 ± 0.14, 0.71 ± 0.20; PLIF ODI: 33.56% ± 1.58%, 25.69% ± 2.69%, 20.01% ± 1.49%, 10.72% ± 0.29%; EQ-5D: 0.33 ± 0.03, 0.39 ± 0.05, 0.62 ± 0.07, 0.72 ± 0.10) were significantly improved compared with those before surgery (Endo-ULBD: 44.56 ± 1.32, 0.33 ± 0.07; PLIF: 43.79 ± 1.91, 0.31 ± 0.09, respectively), with statistically significant differences (P < 0.05); however, there was no significant difference between the two groups at the last follow-up (P > 0.05). At the last follow-up, the excellent and good efficacy rate was 90.3% (28/31) in the Endo-ULBD group and 89.4% (34/38) in the PILF group (χ2 = 0.089, P = 0.993). No mortality, irreversible nerve injury, or even paralysis occurred in either group. Endo-ULBD for lumbar spinal stenosis has the advantages of less trauma, a shortened operation time, and rapid recovery and is an effective alternative for the treatment of lumbar spinal stenosis. Strict surgical indications, reasonable surgical plans, and experienced surgeons are important factors to ensure safety and satisfactory postoperative efficacy.

Full-Endoscopic Foraminotomy with a Novel Large Endoscopic Trephine for Severe Degenerative Lumbar Foraminal Stenosis at L5 S1 Level: An Advanced Surgical Technique.

To (i) introduce the technical notes of a novel full-endoscopic foraminotomy with a large endoscopic trephine for the treatment of severe degenerative lumbar foraminal stenosis at L5 S1 level; (ii) assess the primary clinical outcomes of this technique; (iii) compare the effectiveness of this full-endoscopic foraminotomy technique and other previous techniques for lumbar foraminal stenosis. From January 2019 to August 2019, a retrospective study of L5 S1 severe degenerative lumbar foraminal stenosis was performed in our center. All patients who were diagnosed with severe foraminal stenosis at L5 S1 level and failed conservative treatment for at least 6 weeks were identified. Patients with segmental instability or other coexisting contraindications were excluded. A total of 21 patients were enrolled in the study. All patients were treated by full-endoscopic foraminotomy using large endoscopic trephine. The visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated preoperatively and at 1, 3, 6 months, and 1 year after the surgery, and the modified MacNab criteria were used to evaluate clinical outcomes at the last follow-up. There were 10 males and 11 females with a mean age of 66.38 ± 9.51 years. Five patients had a history of lumbar surgery. The mean operative time was 63.57 ± 25.74 min. The mean follow-up time was 13.29 ± 1.38 months. The mean postoperative hospital stay time was 1.29 ± 0.56 days. The mean preoperative VAS score significantly decreased from 7.38 ± 1.02 to 2.76 ± 1.09 (t = 19.759, P < 0.01), 2.25 ± 1.02 (t = 21.508, P < 0.01), 1.60 ± 1.05 (t = 31.812, P < 0.01), and 1.45 ± 1.10 (t = 25.156, P < 0.01) at 1 month, 3 months, 6 months, and 1 year after the operation. The mean preoperative ODI score significantly decreased from 64.66% ± 4.91% to 30.69% ± 4.59% (t = 33.724, P < 0.01), 29.44% ± 4.50% (t = 32.117, P < 0.01), 24.22% ± 4.14% (t = 33.951, P < 0.01), and 22.44% ± 4.94% (t = 30.241, P < 0.01) at 1 month, 3 months, 6 months, and 1 year after the operation. At the last follow-up, 19 patients (90.48%) got excellent or good outcomes. One patient suffered postoperative dysesthesia, and the symptoms were controlled by conversion treatment. One patient took revision surgery due to the incomplete decompression. There were no other major complications. Percutaneous endoscopic decompression is minimally invasive spine surgery. However, the application of endoscopic decompression for L5 S1 foraminal stenosis is relatively difficult due to the high iliac crest and narrow foramen. Full-endoscopic foraminotomy with the large endoscopic trephine is an effective and safe technique for the treatment of degenerative lumbar foraminal stenosis.

Technical Considerations in Endoscopic Lumbar Decompression.

With technical development and evolution of endoscopic instruments, endoscopic spinal surgery has become one of the standard treatments for various lumbar spinal diseases ranging from a simple contained disc to complicated cases such as highly migrated disc herniation and other pathology combined with bony degeneration to produce foraminal and canal stenosis. Favorable clinical results of endoscopic decompression for lumbar stenotic disease were reported by several authors. However, studies have also reported limitations, such as steep learning curves and a relatively high complication rate compared with conventional techniques. The endoscopic lumbar decompression technique consists of many essential skills to manage different endoscopic anatomic structures of the spine. From the perspective of surgical completion and safety, this article discusses issues related to technical considerations in endoscopic lumbar decompression.

How I do it? Extraforaminal lumbar interbody fusion assisted with biportal endoscopic technique.

BACKGROUND: The biportal endoscope-assisted unilateral foraminal approach is an option for various foraminal pathologies. Lumbar interbody fusion is the standard treatment for foraminal stenosis because both direct and indirect neural decompressions can be obtained. METHOD: We used the biportal endoscopic technique for extraforaminal lumbar interbody fusion (BE-EFLIF) and have described the steps, with discussion regarding the indications, advantages, possible complications, and ways to overcome complications. CONCLUSION: BE-EFLIF achieves direct neural decompression of lateral spinal canal under endoscopic visualization. It achieves indirect neural decompression using a large footprint lordotic interbody cage, while preserving the lumbar posterior arch as much as possible.

Cluster analysis to predict factors associated with sufficient indirect decompression immediately after single-level lateral lumbar interbody fusion.

OBJECTIVE: Changes in indirect decompression using lateral lumbar interbody fusion (LLIF) were classified into three clusters based on cluster analysis. We investigated cage variables and position to assess the effects of single-level LLIF on indirect decompression. METHODS: Cluster analysis was used to classify patients into three groups based on the change in the axial cross-sectional spinal canal area (ΔCSA): group 1 with slight postoperative indirect decompression (n = 35); group 2 with average indirect decompression (n = 19); and group 3 with marked indirect decompression (n = 13). Preoperative and immediately postoperative imaging data were compared between groups. RESULTS: Postoperative segmental lordosis, anterior, posterior, and average disc height increased significantly in each group, but the differences between groups were not significant. Cage length (p = 0.251) and cage height (p = 0.709) did not differ, but cage position differed significantly between groups (p < 0.05). ΔCSA correlated significantly with cage position for all 67 levels (r = 0.411, p < 0.01), but this association was not significant in group 2 (r =  - 0.367, p = 0.122) or group 3 (r =  - 0.005, p = 0.986). ΔCSA correlated with cage height in group 2 (r = 0.645, p < 0.01) and with cage width in group 3 (r = 0.644, p < 0.05). CONCLUSIONS: The cluster analysis results suggest that placing the cage in the posterior position might be effective for expanding the CSA, but other factors, such as cage height or width, may also influence the sufficiency of LLIF.

An intraoperative 3D image-based navigation error during cervical pedicle screw insertion.

A 67-year-old man underwent posterior cervical decompression surgery for ossification of the posterior longitudinal ligament (OPLL) with fixation using cervical pedicle screws (CPSs) guided by intraoperative 3D image-based navigation. Intraoperatively, while creating the screw hole using the navigation probe, the virtual trajectory on the intraoperative navigation screen showed a 10-degree angle discrepancy in the axial plane depending on whether a probing force was or was not applied for making the hole. This was potentially caused by vertebra rotation and a bent probe. Consequently, the CPSs were placed more laterally than the ideal trajectory, which resulted in <2 mm lateral perforation to the foramen transversarium. There were no screw insertion-related perioperative complications. Based on this case, we conclude that navigation error during CPS insertion can occur even with intraoperative 3D image-based navigation. The risk of a bowed navigation probe caused by posterior cervical muscle and vertebra rotation should be considered, even with use of a navigation reference frame.

Effect of different designs of interspinous process devices on the instrumented and adjacent levels after double-level lumbar decompression surgery: A finite element analysis.

Recently, various designs and material manufactured interspinous process devices (IPDs) are on the market in managing symptomatic lumbar spinal stenosis (LSS). However, atraumatic fracture of the intervening spinous process has been reported in patients, particularly, double or multiple level lumbar decompression surgery with IPDs. This study aimed to biomechanically investigate the effects of few commercial IPDs, namely DIAMTM, CoflexTM, and M-PEEK, which were implanted into the L2-3, L3-4 double-level lumbar spinal processes. A validated finite element model of musculoskeletal intact lumbar spinal column was modified to accommodate the numerical analysis of different implants. The range of motion (ROM) between each vertebra, stiffness of the implanted level, intra stress on the intervertebral discs and facet joints, and the contact forces on spinous processes were compared. Among the three implants, the Coflex system showed the largest ROM restriction in extension and caused the highest stress over the disc annulus at the adjacent levels, as well as the sandwich phenomenon on the spinous process at the instrumented levels. Further, the DIAM device provided a superior loading-sharing between the two bridge supports, and the M-PEEK system offered a superior load-sharing from the superior spinous process to the lower pedicle screw. The limited motion at the instrumented segments were compensated by the upper and lower adjacent functional units, however, this increasing ROM and stress would accelerate the degeneration of un-instrumented segments.

Posterior Percutaneous Transpedicular Endoscopic Approach for Treating Single-Segment Cervical Myelopathy.

BACKGROUND: Standard posterior percutaneous endoscopic cervical discectomy (PECD) is considered an effective minimally invasive surgery. Although standard PECD can be used to treat radiculopathy with relatively minimal trauma, it is still a challenge to use this approach for treating myelopathy. OBJECTIVE: This report is aimed at first describing a posterior transpedicular approach under endoscopy for myelopathy and evaluating the feasibility and short-term clinical effects of this approach. METHODS: In our retrospective analysis between Feb. 2016 to Mar. 2017, 16 patients managed with PECD using the posterior transpedicular approach for symptomatic single-segment myelopathy. Surgery involved drilling 1/2 to 2/3 of the medial portion of the pedicle under endoscopy to provide sufficient space and an appropriate angle for inserting the endoscope into the spinal canal, followed by ventral decompression of the spinal cord. Computed tomography and magnetic resonance imaging were used to evaluate pedicle healing and spinal cord decompression. The primary outcomes included a visual analog scale (VAS) scores of axial neck pain and Japanese Orthopaedic Association (JOA) scores of neurological conditions. RESULTS: All patients completed a 1-year follow-up examination. The mean duration of surgery was 95.44 ± 19.44 min (52-130 min). The fluoroscopy duration was 5.88 ± 1.05 (4-7). The VAS scores of axial pain significantly improved from 6.94 ± 0.75 preoperatively to 2.88 ± 1.22 postoperatively (P < 0.05). The mean JOA scores improved from 8.50 ± 1.12 preoperatively to 14.50 ± 1.46 at the final follow-up (P < 0.05). The effects were excellent in 8 cases, good in 6 cases, and fair in 2 cases. After partial pedicle excision, the width of the remaining pedicle was 1.70 ± 0.22 mm postoperatively and significantly recovered to 3.38 ± 0.49 mm at the 1-year follow-up. There were no surgery-related complications, such as dural tearing, spinal cord injury, nerve root injury, pedicle fracture, and cervical hematocele or infection. CONCLUSIONS: The posterior transpedicular approach is an effective method for the treatment of myelopathy in select patients and is a supplement to the described surgical approach for PECD.