Is Proximal Triangular Fixation Better than the Conventional Method in Adult Spinal Deformity Surgery?

In adult spinal deformity (ASD) surgery, one of the key factors working to prevent proximal junctional kyphosis is the proximal anchor. The aim of this study was to compare clinical and radiographic outcomes of triangular fixation with conventional fixation as proximal anchoring techniques in ASD surgery. We retrospectively evaluated 54 patients who underwent corrective spinal fusion for ASD. Fourteen patients underwent proximal triangular fixation (Group T; average 74.6 years), and 40 patients underwent the conventional method (Group C; average 70.5 years). Clinical and radiographic outcomes were assessed using visual analogue scale (VAS) values for back pain and the Oswestry disability index (ODI). Radiographic evaluation was also collected preoperatively and postoperatively. Surgical times and intraoperative blood loss of the two groups were not significantly different (493 vs 490 min, 1,260 vs 1,173 mL). Clinical outcomes such as VAS and ODI were comparable in the two groups. Proximal junctional kyphosis in group T was slightly lower than that of group C (28.5% vs 47.5%, p=0.491). However, based on radiology, proximal screw pullout occurred significantly less frequently in the triangular fixation group than the conventional group (0.0% vs 22.5%, p=0.049). Clinical outcomes in the two groups were not significantly different.

Retrospective Cohort Study of Early versus Delayed Ballon Kyphoplasty Intervention for Osteoporotic Vertebral Fracture Treatment.

Objectives: To investigate the outcomes of early balloon kyphoplasty (BKP) intervention compared with late intervention for osteoporotic vertebral fracture (OVF). Background: Osteoporotic vertebral fracture can lead to kyphotic deformity, severe back pain, depression, and disturbances in activities of daily living (ADL). Balloon kyphoplasty has been widely utilized to treat symptomatic OVFs and has proven to be a very effective surgical option for this condition. Furthermore, BKP is relatively a safe and effective method due to its reduced acrylic cement leakage and greater kyphosis correction. Materials and Methods: A retrospective cohort study was conducted at our hospital for patients who underwent BKP for osteoporotic vertebral fractures in the time frame between January 2020 and December 2022. Ninety-nine patients were included in this study, and they were classified into two groups: in total, 36 patients underwent early BKP intervention (EI) at <4 weeks, and 63 patients underwent late BKP intervention (LI) at ≥4 weeks. We performed a clinical, radiological and statistical comparative evaluation for the both groups with a mean follow-up of one year. Results: Adjacent segmental fractures were more frequently observed in the LI group compared to the EI group (33.3% vs. 13.9%, p = 0.034). There was a significant improvement in postoperative vertebral angles in both groups (p = 0.036). The cement volume injected was 7.42 mL in the EI, compared with 6.3 mL in the LI (p = 0.007). The mean surgery time was shorter in the EI, at 30.2 min, compared with 37.1 min for the LI, presenting a significant difference (p = 0.0004). There was no statistical difference in the pain visual analog scale (VAS) between the two groups (p = 0.711), and there was no statistical difference in cement leakage (p = 0.192). Conclusions/Level of Evidence: Early BKP for OVF treatment may achieve better outcomes and fewer adjacent segmental fractures than delayed intervention.

A Novel Technique for Basilar Invagination Treatment in a Patient with Klippel-Feil Syndrome: A Clinical Example and Brief Literature Review.

Objectives and Background: To present a novel technique of treatment for a patient with basilar invagination. Basilar invagination (BI) is a congenital condition that can compress the cervicomedullary junction, leading to neurological deficits. Severe cases require surgical intervention, but there is debate over the choice of approach. The anterior approach allows direct decompression but carries high complication rates, while the posterior approach provides indirect decompression and offers good stability with fewer complications. Materials and Methods: A 15-year-old boy with severe myelopathy presented to our hospital with neck pain, bilateral upper limb muscle weakness, and hand numbness persisting for 4 years. Additionally, he experienced increased numbness and gait disturbance three months before his visit. On examination, he exhibited hyperreflexia in both upper and lower limbs, muscle weakness in the bilateral upper limbs (MMT 4), bilateral hypoesthesia below the elbow and in both legs, mild urinary and bowel incontinence, and a spastic gait. Radiographs revealed severe basilar invagination (BI). Preoperative images showed severe BI and that the spinal cord was severely compressed with odontoid process. Results: The patient underwent posterior surgery with the C-arm free technique. All screws including occipital screws were inserted into the adequate position under navigation guidance. Reduction was achieved with skull rotation and distraction. A follow-up at one year showed the following results: Manual muscle testing results and sensory function tests showed almost full recovery, with bilateral arm recovery (MMT 5) and smooth walking. The cervical Japanese Orthopedic Association score of the patient improved from 9/17 to 16/17. Postoperative images showed excellent spinal cord decompression, and no major or severe complications had occurred. Conclusions: Basilar invagination alongside Klippel-Feil syndrome represents a relatively uncommon condition. Utilizing a posterior approach for treating reducible BI with a C-arm-free technique proved to be a safe method in addressing severe myelopathy. This novel navigation technique yields excellent outcomes for patients with BI.

New Spinal Shortening Technique for Tethered Cord Syndrome: A Technical Note.

Background and Objectives: To present a new spinal shortening technique for tethered cord syndrome. Tethered cord syndrome (TCS) is a debilitating condition leading to progressive neurological decline. Surgical detethering for TCS is the gold standard of treatment. However, symptomatic retethering of TCS has been reported in 5%-50% of patients after initial release. To solve this problem, posterior spinal shortening osteotomy has been reported. This technique has risks of massive blood loss and neurological deterioration. The authors hereby report a new safe spinal shortening technique for tethered cord syndrome. Materials and Methods: A 31-year-old man with gait disturbance was referred to our hospital. After the delivery of treatment, he underwent surgical untethering of the spinal cord in another hospital. He had hyperreflexia of the Achilles tendon reflex and bilateral muscle weakness of the legs (MMT 3-4). He also had urinary and bowel incontinence, and total sensory loss below L5. An anteroposterior lumbar radiogram indicated partial laminectomy of L3 and L4. Lumbar MRI showed retethering of spinal cord. Results: The patient underwent a new spinal shortening technique for tethered cord syndrome under the guidance of O-arm navigation. First, from the anterior approach, disectomy from T12 to L3 was performed. Second, from the posterior approach, Ponte osteotomy was performed from T12 to L3, shortening the spinal column by 15 mm. The patient was successfully treated surgically. Postoperative lumbar MRI showed that the tension of the spinal cord was released. Manual muscle testing results and the sensory function of the left leg had recovered almost fully upon final follow-up at one year. Conclusions: A retethered spinal cord after initial untethering is difficult to treat. This new spinal shortening technique can represent another good option to release the tension of the spinal cord.

Comparison of C-Arm-Free Oblique Lumbar Interbody Fusion L5-S1 (OLIF51) with Transforaminal Lumbar Interbody Fusion L5-S1 (TLIF51) for Adult Spinal Deformity.

Background and Objectives: Adult spinal deformity (ASD) surgery, L5-S1 lordosis is very important factor. The main objective of the research is to retrospectively compare symptomatic presentation and radiological presentation in the sequelae of oblique lumbar inter-body spinal fusion at L5-S1 (OLIF51) and transforaminal lumbar interbody fusion (TLIF) for ASD. Materials and Methods: We retrospectively evaluated 54 patients who underwent corrective spinal fusion for ASD between October 2019 and January 2021. Thirteen patients underwent OLIF51 (average 74.6 years old, group O) and 41 patients underwent TLIF51 (average 70.5 years old, group T). Mean follow-up period was 23.9 months for group O and 28.9 months for group T, ranging from 12 to 43 months. Clinical and radiographic outcomes are assessed using values including visual analogue scale (VAS) for back pain and Oswestry disability index (ODI). Radiographic evaluation was also collected preoperatively and at 6, 12, and 24 months postoperatively. Results: Surgical time in group O was less than that in group T (356 min vs. 492 min, p = 0.003). However, intraoperative blood loss of both groups were not significantly different (1016 mL vs. 1252 mL, p = 0.274). Changes in VAS and ODI were similar in both groups. L5-S1 angle gain and L5-S1 height gain in group O were significantly better than those of group T (9.4° vs. 1.6°, p = 0.0001, 4.2 mm vs. 0.8 mm, p = 0.0002). Conclusions: Clinical outcomes were not significantly different in both groups, but surgical time in OLIF51 was significantly less than that in TLIF51. The radiographic outcomes showed that OLIF51 created more L5-S1 lordosis and L5-S1 disc height compared with TLIF 51.

A C-Arm-Free Minimally Invasive Technique for Spinal Surgery: Cervical and Thoracic Spine.

Background and Objectives: C-arm-free MIS techniques can offer significantly reduced rates of postoperative complications such as inadequate decompression, blood loss, and instrumentation misplacement. Another advantageous long-term aspect is the notably diminished exposure to radiation, which is known to cause malignant changes. This study emphasizes that, in some cases of spinal conditions that require a procedural intervention, C-arm-free MIS techniques hold stronger indications than open surgeries guided by image intensifiers. Materials and Methods: This study includes a retrospective analysis and review of various cervical and thoracic spinal procedures, performed in our hospital, applying C-arm-free techniques. The course of this study explains the basic steps of the procedures and demonstrates postoperative and intraoperative results. For anterior cervical surgery, we performed OPLL resection, while for posterior cervical surgery, we performed posterior fossa decompression for Chiari malformation, minimally invasive cervical pedicle screw fixation (MICEPS), and modified Goel technique with C1 lateral mass screw for atlantoaxial subluxation. Regarding the thoracic spine, we performed anterior correction for Lenke type 5 scoliosis and transdiscal screw fixation for diffuse idiopathic skeletal hyperostosis fractures. Results: C-arm-free techniques are safe procedures that provide precise and high-quality postoperative results by offering sufficient spine alignment and adequate decompression depending on the case. Navigation can offer significant assistance in the absence of normal anatomical landmarks, yet the surgeon should always appraise the quality of the information received from the software. Conclusions: Navigated C-arm-free techniques are safe and precise procedures implemented in the treatment of surgically demanding conditions. They can significantly increase accuracy while decreasing operative time. They represent the advancement in the field of spine surgery and are hailed as the future of the same.

Our C-Arm-Free Minimally Invasive Technique for Spinal Surgery: The Thoracolumbar and Lumbar Spine-Based on Our Experiences.

Background and Objectives: The implementation of intraoperative imaging in the procedures performed under the guidance of the same finds its history dating back to the early 1990s. This practice was abandoned due to many deficits and practicality. Later, fluoroscopy-dependent techniques were developed and have been used even in the present time, albeit with several disadvantages. With the recent advancement of several complex surgical techniques, which demand higher accuracy and are in conjunction with the existence of radiation exposure hazard, C-arm-free techniques were introduced. In this review study, we aim to demonstrate the various types of these techniques performed in our hospital. Materials and Methods: We have retrospectively analyzed and collected imaging data of C-arm-free, minimally invasive techniques performed in our hospital. The basic steps of the procedures are described, following with a discussion, along with the literature of findings, enlisting the merits and demerits. Results: MIS techniques of the thoracolumbar and lumbar spine that do not require the use of the C-arm can offer excellent results with high precision. However, several disadvantages may prevail in certain circumstances such as the navigation accuracy problem where in the possibility of perioperative complications comes a high morbidity rate. Conclusions: The accustomedness of performing these techniques requires a steep learning curve. The increase in accuracy and the decrease in radiation exposure in complex spinal surgery can overcome the burden hazards and can prove to be cost-effective.

C-arm Free O-arm Navigated Posterior Atlantoaxial Fixation in Down Syndrome: A Technical Note.

The surgical treatment of pediatric atlantoaxial subluxation (AAS) in Down syndrome (DS) remains technically challenging due to radiation exposure and complications such as vertebral artery injury and nonunion. The established treatment is fixation with a C1 lateral mass screw and C2 pedicle screw (modified Goel technique). However, this technique requires fluoroscopy for C1 screw insertion. To avoid exposing the operating team to radiation we present here a new C-arm free O-arm navigated surgical procedure for pediatric AAS in DS. A 5-year-old male DS patient had neck pain and unsteady gait. Radiograms showed AAS with an atlantodental interval of 10 mm, and irreducible subluxation on extension. CT scan showed Os odontoideum and AAS. MRI demonstrated spinal cord compression between the C1 posterior arch and odontoid process. We performed a C-arm free O-arm navigated modified Goel procedure with postoperative halo-vest immobilization. At oneyear follow-up, good neurological recovery and solid bone fusion were observed. The patient had no complications such as epidural hematoma, infection, or nerve or vessel injury. This novel procedure is a useful and safe technique that protects surgeons and staff from radiation risk.

Posterolateral Floating Technique for the Thoracic Ossification of the Posterior Longitudinal Ligament with Navigation: A Technical Note.

We describe a floating technique via a posterolateral approach with intraoperative O-arm navigation to facilitate decompression of the spinal cord in thoracic myelopathy due to severe ossification of the posterior longitudinal ligament (OPLL). A 62-year-old man with myelopathy due to thoracic OPLL had left-leg muscle weakness, urinary disturbance, and spastic gait. Bilateral leg pain and gait disturbance had persisted for 2 years. He was successfully treated by the posterolateral OPLL floating procedure and posterior pedicle fixation under O-arm navigation. At a 2-year follow-up, manual muscle testing results and sensory function of the left leg had recovered fully. His cervical Japanese Orthopedic Association score had improved from 5/12 to 11/12. The novel intraoperative O-arm navigation-guided posterolateral floating procedure for thoracic OPLL is effective for achieving precise decompression and strong fixation with a posterior approach only and can provide an excellent result for severe thoracic OPLL without the risk of adverse events from intraoperative radiation.

Revision for cage migration after transforaminal/posterior lumbar interbody fusion: how to perform revision surgery?

BACKGROUND: Symptomatic pseudarthrosis and cage migration/protrusion are difficult complications of transforaminal or posterior lumbar interbody fusion (TLIF/PLIF). If the patient experiences severe radicular symptoms due to cage protrusion, removal of the migrated cage is necessary. However, this procedure is sometimes very challenging because epidural adhesions and fibrous union can be present between the cage and vertebrae. We describe a novel classification and technique utilizing a navigated osteotome and the oblique lumbar interbody fusion at L5/S1 (OLIF51) technique to address this problem. METHODS: This retrospective study investigated consecutive patients with degenerative lumbar diseases who underwent TLIF/PLIF. Symptomatic cage migration was evaluated by direct examination, radiography, and/or computed tomography (CT) at 1, 3, 6, 12, and 24 months of follow-up. Cage migration/protrusion was defined as symptomatic cage protrusion > 5 mm from the posterior border of the over and underlying vertebral body compared with initial CT. We evaluated patient characteristics including body mass index, smoking history, fusion level, and cage type. A total of 113 patients underwent PLIF/TLIF (PLIF n = 30, TLIF n = 83), with a mean age of 71.1 years (range, 28-87 years). Mean duration of follow-up was 25 months (range, 12-47 months). RESULTS: Cage migration was identified in 5 of 113 patients (4.4%). All cases of symptomatic cage migration involved the L5/S1 level and the TLIF procedure. Risk factors for cage protrusion were age (younger), sex (male), and level (L5/S1). The mean duration to onset of cage protrusion was 3.2 months (range, 2-6 months). We applied a new classification for cage protrusion: type 1, only low back pain without new radicular symptoms; type 2, low back pain with minor radicular symptoms; or type 3, cauda equina syndrome and/or severe radicular symptoms. According to our classification, one patient was in type 1, three patients were in type 2, and one patient was in type 3. For all cases of cage migration, revision surgery was performed using a navigated high-speed burr and osteotome, and the patient in group 1 underwent additional PLIF without removal of the protruding cage. Three revision surgeries (group 2) involved removal of the protruding cage and PLIF, and one revision surgery (group 3) involved anterior removal of the cage and OLIF51 fusion. CONCLUSIONS: The navigated high-speed burr, navigated osteotome, and OLIF51 technique appear very useful for removing a cage with fibrous union from the disc in patients with pseudarthrosis. This new technique makes revision surgery after cage migration much safer, and more effective. This technique also reduces the need for fluoroscopy.

Innovative C-Arm-Free Navigation Technique for Posterior Spinal Fixation for Atlantoaxial Subluxation: A Technical Note.

Study design: Technical note. Objectives: To present a novel C-arm-free technique guided by navigation to insert and place a C1 lateral mass screw. Background and Objectives: Atlantoaxial subluxation (AAS) is a relatively common sequelae in patients with rheumatoid arthritis (RA) and upper cervical trauma. If they present with severe symptoms, surgical intervention such as posterior fusion is indicated. The established treatment for AAS is fixation with a C1 lateral mass screw and C2 pedicle screw (modified Goel technique) to achieve bony fusion. However, this technique requires fluoroscopy for C1 screw insertion. To avoid exposing the operating team to radiation, we present here a novel C-arm-free C1 lateral mass screw insertion technique for AAS. Materials and Methods: A 67-year-old man was referred to our hospital with neck pain, quadriparesis, and clumsiness and numbness of both upper and lower limbs. He had undergone C3-6 posterior fusion previously in another hospital. In physical examination, he had severe muscle weakness of bilateral upper limbs and hypoesthesia of all four limbs. He had hyper-reflexia of bilateral lower limbs and pollakiuria. His Japanese orthopedic score was 8 points out of 17. Preoperative radiograms showed AAS with an atlantodental interval (ADI) of 7 mm. MRI indicated retro-odontoid pseudotumor and severe spinal cord compression at the C1-2 level. The patient underwent posterior atlantoaxial fixation under navigation guidance. To prevent epidural bleeding during the insertion and placement of a C1 lateral mass screw, we have here defined a novel screw insertion technique. Results: The surgical time was clocked as 127 min and blood loss was 100 mL. There were no complications per-operatively or in the postoperative period. The patient showed almost full recovery (JOA 16/17) at two months follow-up and a solid bony fusion was noticed in the radiograms at one year follow-up. Conclusions: This novel surgical procedure and C1 lateral mas screw placement technique is a practical and safe method in recent advances of AAS treatment. Procedurally, the technique helps prevent epidural bleeding from the screw entry point and also allows for proper C1 screw insertion under navigation guidance without exposing surgeons and staff to the risk of fluoroscopic radiation.

Comparison of Navigated Expandable Vertebral Cage with Conventional Expandable Vertebral Cage for Minimally Invasive Lumbar/Thoracolumbar Corpectomy.

Background and Objectives: The thoracolumbar burst fracture is one of the most common spinal injuries. If the patient has severe symptoms, corpectomy is indicated. Currently, minimally invasive corpectomy with a navigated expandable vertebral cage is available thanks to spinal surgical technology. The aim of this study is to retrospectively compare clinical and radiographic outcomes of conventional and navigational minimally invasive corpectomy techniques. Materials and Methods: We retrospectively evaluated 21 patients who underwent thoracolumbar minimally invasive corpectomy between October 2016 and January 2021. Eleven patients had a navigated expandable cage (group N) and 10 patients had a conventional expandable cage (group C). Mean follow-up period was 31.9 months for group N and 34.7 months for group C, ranging from 12 to 42 months in both groups. Clinical and radiographic outcomes are assessed using values including visual analogue scale (VAS) for back pain and Oswestry disability index (ODI). This data was collected preoperatively and at 6, 12, and 24 months postoperatively. Results: Surgical time and intraoperative blood loss of both groups were not significantly different (234 min vs. 267 min, 656 mL vs. 786 mL). Changes in VAS and ODI were similar in both groups. However, lateral cage mal-position ratio in group N was lower than that of group C (relative risk 1.64, Odds ratio 4.5) and postoperative cage sinking was significantly lower in group N (p = 0.033). Conclusions: Clinical outcomes are not significantly different, but radiographic outcomes of lateral cage mal-position and postoperative cage sinking were significantly lower in the navigation group.

The Most Significant Factor Affecting Gait and Postural Balance in Patients' Activities of Daily Living Following Corrective Surgery for Deformity of the Adult Spine.

Background and Objectives: Gait ability and spinal postural balance affect ADL in patients who underwent adult spinal deformity (ASD) surgery. However, it is still unclear how to determine what the cause is. This study was done to investigate various factors affecting gait, postural balance and activities of daily living (ADL) in patients who were operated on for ASD over a period of one year, following corrective surgery. Materials and Method: A cohort of 42 (2 men, 40 women, mean age, 71.1 years) who were operated on for ASD were included in this study. According to Oswestry Disability Index (ODI), based on their ADL, patients were segregated into satisfied and unsatisfied groups. Gait and postural balance abilities were evaluated before and after the operative procedure. Radiographs of spine and pelvis as well as the rehabilitation data (static balance, standing on single-leg; dynamic postural adaptation, timed up and go test (TUG); Gait Capability, walk velocity for a distance of 10 m) were acquired 12 months after surgery and analyzed. Spinopelvic parameters such as (lumbar lordosis (LL), pelvic tilt (PT), sagittal vertical axis (SVA), pelvic incidence (PI)) were marked and noted. The factors which affect patients' satisfaction with their ADL were evaluated. Results: The ADL satisfied group included 18 patients (1 man, 17 women, mean age 68.6 years) and the unsatisfied group included 24 patients (1 man, 23 women, mean age 73.1 years). One year after the surgery, the two groups were tested. TUG (8.5 s vs. 12.8 s), 10 m walk velocity (1.26 m/s vs. 1.01 m/s), and single leg standing test (25 s vs. 12.8 s) were regarded as notably different. According to logistic regression analysis, only TUG was extracted as a significant factor. The cut-off value was 9.7 s, with sensitivity 75%, specificity 83%, area under the curve 0.824, and a 95% confidence interval of 0.695-0.953. Conclusions: A significant factor among all evaluations in postoperative ASD patients was TUG, for which the cut-off value for ADL satisfaction was 9.7 s.

Transtubular Endoscopic Posterolateral Decompression of the L5 Root under Navigation and O-arm: A Technical Note.

Among studies evaluating minimally invasive surgical (MIS) decompression of the L5 root, techniques involving transtubular endoscopic decompression under O-arm navigation are rare. We present the case of a 68-yearold woman with left leg pain, muscle weakness and gait disturbance of one month duration. The patient underwent transtubular endoscopic decompression under O-arm navigation. There is no radiation hazard to the operating room staff with this procedure. After surgery, the patient had significant pain relief and her left lower limb motor function had improved by follow-up at one year. C-arm-free endoscopic L5 root decompression is a safe and effective procedure.

Laminar closure rates in patients with cervical myelopathies treated with either open-door laminoplasty with reattachment of spinous processes and extensor musculature or Hirabayashi open-door laminoplasty: a case-control study.

PURPOSE: The presence of preoperative kyphosis has been identified as a risk factor for laminar closure (LC). We have been performing modified open-door laminoplasty with reattachment of the spinous processes and extensor musculature for patients with reduced cervical lordosis because this procedure can prevent progression of cervical kyphosis. This procedure may also prevent LC. The purpose of this study was to evaluate the rate of LC after the modified open-door laminoplasty. METHODS: A total of 104 patients who underwent open-door laminoplasty were retrospectively reviewed. Of these patients, 18 underwent modified open-door laminoplasty (group M), whereas the other 86 underwent Hirabayashi open-door laminoplasty (group H). Group H was divided into two classes according to the preoperative cervical lordosis angle (group H1 ≤ 10° vs. group H2 ≥ 11°). All 18 patients in group M had a preoperative lordosis angle ≤10°. The outcomes were assessed using the rate of LC, the cross-sectional area (CSA) of the erector muscle on magnetic resonance imaging, and the Japanese Orthopaedic Association score (JOA score). RESULTS: The rate of laminar closure was significantly lower in group M (39 %) than in group H1 (76 %) (P < 0.01). The CSAs tended to be larger in the muscle preservation side of group M than in the other groups. There was no significant difference in the JOA score among the three groups. CONCLUSIONS: Although patients with decreased cervical lordosis have a higher risk of LC, the results suggested that modified open-door laminoplasty could reduce the rate of LC compared with Hirabayashi open-door laminoplasty.

Computer-assisted Minimally Invasive Posterior Lumbar Interbody Fusion without C-arm Fluoroscopy.

Computer-assisted spinal surgery is becoming more common; however, this is the first technical report to describe the technique of minimally invasive spinal posterior lumbar interbody fusion (MIS-PLIF) without using C-arm fluoroscopy. The authors report 2 years of follow-up of a 49-year-old female patient with L4 degenerative spondylolisthesis. The patient suffered from low back pain and intermittent claudication for more than 6 years. The authors performed computer-assisted MIS-PLIF without C-arm fluoroscopy. Instead, O-arm® navigation, the use of which reduces radiation exposure to patients as well as others in the operating room, was employed. Surgery was successful, and correct lumbar alignment was maintained. She had neither neurological deficits nor low back pain at her 12-month final follow-up. In conclusion, computer-assisted MIS-PLIF without C-arm fluoroscopy is a useful technique that reduces radiation exposure to the surgeon and operating room staff.

Neurological Recovery after Posterior Spinal Surgery in Patients with Metastatic Epidural Spinal Cord Compression.

Metastatic epidural spinal cord compression (MESCC) is a common complication in patients with a malignant tumor, but it is difficult to decide the proper time to perform the necessary surgery. Here we analyzed the prognostic factors for postoperative walking ability. We retrospectively reviewed the cases of 112 MESCC patients treated surgically at our institute and divided them into ambulatory (n＝ 88) and non-ambulatory (n＝24) groups based on their American Spinal Injury Association (ASIA) Impairment Scale grades at the final follow-up. We also classified the patients preoperatively using the revised Tokuhashi score. We assessed the correlation between preoperative or intraoperative factors and postoperative walking ability in both groups. Of the 10 patients classified preoperatively as grade A or B, 2 (20% ) were ambulatory at the final follow-up. Of the 102 patients classified preoperatively as grade C, D or E, 86 (84% ) were ambulatory at the final follow-up (p＜0.001). There were no significant differences between the groups in the average total Tokuhashi score. Our analysis revealed that the severity of paralysis significantly affects neurological recovery in patients with MESCC. Patients with MESCC should receive surgery before the preoperative ASIA Impairment Scale grade falls below grade C.

Biomechanical Comparison of Posterior Fixation Using Spinal Instrumentation and Conventional Posterior Plate Fixation in Unstable Vertical Sacral Fracture.

Vertical sacral fracture is one of the most difficult fractures to treat. Posterior fixation using spinal dual rods is a novel method for treating this fracture, but its biomechanical strength has not yet been reported. The aim of this study was to evaluate the biomechanical strength produced by posterior fixation using spinal instrumentation. Sacral fractures were created in eight pelvic bone models and classifi ed into a posterior plate fixation group [P group, n＝4] and a spinal instrumentation group [R group, n＝4]. The biomechanical strength was tested by pushing down on the S1 vertebra from the top. The mean maximum loads were 1,057.4 N and 1,489.4 N in the P and R groups, respectively (p＝ 0.014). The loads applied to the construct at displacements of 5mm and 7.5mm from the start of the universal testing machine loading were also significantly higher in the R group. The mean stiffness levels in the P and R groups were 88.3N/mm and 119.6N/mm, respectively (p＝0.014). Posterior fixation using spinal instrumentation is biomechanically stronger than conventional posterior plate fixation. This procedure may be the optimal method for treating unstable sacral fracture fixation.

A rare course of scoliosis associated with Chiari malformation and syringomyelia.

Spinal deformity is an important clinical manifestation of Chiari I malformation (CM-I) and syringomyelia. Here we report the result of an 8-year follow-up of a 13-year-old girl with severe scoliosis associated with Chiari malformation and a large syringomyelia. The patient presented at our hospital at the age of 13 with a 68° scoliosis. Magnetic resonance imaging showed Chiari malformation and a large syringomyelia. Neurosurgical treatment involved foramen magnum decompression and partial C1 laminectomy, but the scoliosis still progressed. We present the first case report of a rare course of scoliosis in a patient with CM-I and a large syringomyelia.

Use of a Triaxial Accelerometer to Measure Changes in Gait Sway and Related Motor Function after Corrective Spinal Fusion Surgery for Adult Spinal Deformity.

Background: Adult spinal deformity is a complex condition that causes lower back pain, causing spinal imbalance and discomfort in activities of daily life. After corrective spinal surgery, patients' gait and balance abilities might not revert to normalcy and they might be at increased risk of falling. Therefore, early evaluation of such a risk is imperative to prevent further complications such as a fall, or even worse, fractures in post-surgery ASD patients. However, there has been no report of an investigation of such early changes in gait sway before and after ASD surgery. This is a prospective to investigate changes in gait sway before and following ASD surgery, using accelerometers, and also to examine motor function related to postoperative gait sway. Methods: Twenty patients were included who underwent corrective surgery as treatment for ASD, from October 2019 to January 2023. Measurement parameters included a 10 m walking test and the timed up-and-go test (TUG), gait sway was evaluated using accelerometers (root mean square; RMS), and hip flexion and knee extension muscle strength were tested. RMS included RMS vertical: RMSV; RMS anterior posterior: RMSAP; RMS medial lateral: RMSML. The radiographic spinopelvic parameters were also evaluated preoperatively and postoperatively. p < 0.05 was noted as remarkably significant. Results: Preoperative and postoperative RMSV were 1.07 ± 0.6 and 1.31 ± 0.8, respectively (p < 0.05). RMSML significantly decreased from 0.33 ± 0.2 to 0.19 ± 0.1 postoperatively (p < 0.01). However, RMSAP did not change postoperatively (0.20 ± 0.2 vs. 0.14 ± 0.1, p > 0.05). Patients' one-month postoperative hip flexor muscle strength became significantly weaker (0.16 ± 0.04 vs. 0.10 ± 0.03 kgf/kg, p = 0.002), but TUG was maintained (11.6 ± 4.2 vs. 11.7 s, p = 0.305). RMSV was negatively correlated with quadriceps muscle strength and positively with TUG. RMSAP was negatively correlated with quadriceps muscle strength. All spinopelvic parameters became normal range after surgery. Conclusions: After corrective spinal fusion for ASD patients, the gait pattern improved significantly. Iliopsoas (hip flexor) and quadriceps femoris (knee extensor) muscles may play important roles for gait anterolateral and vertical swing, respectively.