Spine Surgery and Related Research最新文献

Introduction: There is limited evidence between lumbar disk degeneration and normal lumbar segmental range of motions (SRMs), because previous studies were skewed by age and lacked large cohort of asymptomatic data. We aimed to characterize the normal lumbar SRMs according to age and gender and determine its association with disk degeneration.

Methods: A total of 639 healthy Japanese volunteers (≥50 individuals of each decade of age from 20 to 79) without any symptom or morphological spinal abnormalities, who underwent lumbar radiograph and magnetic resonance image (MRI), were selected retrospectively. SRMs were evaluated by the flexion-extension radiographs taken in the recumbent position. Disk degenerations were assessed according to the Pfirrmann grade using MRI T2 imaging.

Results: The mean SRMs became larger in the lower lumbar level. The range of the mean SRMs was smallest at L1-2 and largest at L4-5: 6 to 9 degrees at L1/2, to peaking at 11-14 degrees at L4/5 in male, and 6-8 degrees at L1/2, to peaking at 11-17 degrees at L4/5 in female. Lumbar disk degeneration progressed faster with age in the lower lumbar spine than in the upper lumbar level. SRM did not change depending on the severity of disk degeneration in upper lumbar spine, but significantly decreased with progressive disk degeneration in the lower lumbar spine.

Conclusions: These findings could help to identify the normal lumbar SRMs that might be useful to evaluate the instability or inflexibility in the clinical situation. Furthermore, our results demonstrated the transition of the normative lumbar SRMs based on age, gender, and lumbar level.

Introduction: Fifth lumbar (L5) vertebral morphology contributes to spondylolysis. However, there are no comprehensive examinations of the three-dimensional vertebral shape in early-stage cases. This study aimed to investigate the overall L5 vertebral shape in early-stage spondylolysis.

Methods: Homologous models of the L5 vertebra were constructed using computed tomography data from 72 patients with early-stage spondylolysis (SP group) and 95 patients without spondylolysis (CON group). Principal component analysis was performed on the three-dimensional coordinates of all vertices of the generated homologous models. The groups' principal component scores were compared.

Results: Principal component (PC) 3, which represents the morphology of the cross-sectional area of the vertebral body; length of pedicle, neural arch, and isthmus; shape of the vertebral body; and spinous process orientation were significantly higher in the SP group than in the CON group. Additionally, the SP group showed higher values for PC10, which represents the morphology of the anteroposterior length of the vertebral body and transverse process orientation. Compared to the CON group, the SP group's PC3 had a smaller cross-sectional vertebral body area, longer pedicle and neural arch length, larger dorsal wedge shape of the vertebral body, horizontally oriented spinous process, and a shorter isthmus length. PC10, compared with the CON group, indicated the SP group had a shorter anteroposterior length of the superior and inferior surfaces of the vertebral body and a coronally oriented transverse process.

Conclusions: The overall L5 vertebral shape differed between individuals with and without early-stage spondylolysis. Our findings suggest that a wedge-shaped vertebral body and shorter isthmus length may be associated with spondylolysis development. Our study may be valuable in elucidating spondylolysis pathogenesis and may contribute to early detection and prevention.

Introduction: Minimally invasive surgical treatment of myelopathy caused by central thoracic disc herniation (TDH) is challenging to carry out because reaching the herniation site is difficult and the thoracic spinal cord is fragile. In this study, using the posterior-lateral approach for central TDH with myelopathy, we present a novel procedure of transcostal microendoscopic discectomy (TCMED).

Technical note: The patient was operated in a prone position under general anesthesia. At a preoperatively determined distance from the midline, an 18-mm-long longitudinal incision was conducted, and using a 25-degree microendoscope, the operation was carried out. The endoscope was placed at an inward angle of approximately 50 degrees in the vertical direction. The ribs adjacent to the disc were identified, and the disc was exposed by resecting the ribs using a surgical high-speed drill while preserving the cortical bone of the ribs on the pleural side. The herniation was identified by drilling the ventral side of the disc and was then successfully removed. After discectomy, the dura mater expanded ventrally. Three male patients (mean age, 47.3 years) were treated, with 20 weeks of follow-up on average, 237.7-min mean operative time, and 26.7-mL mean blood loss. The average preoperative modified Japanese Orthopedic Association score was 5.2/11, which improved to 9.5/11 postoperatively, with a 75.6% average recovery rate. The 10-s step test score improved from an average of eight times preoperatively to 20 times postoperatively. No serious perioperative or postoperative complications or residual rib pain were observed.

Conclusions: The proposed TCMED approach for treating central TDH that causes myelopathy allows for safe access to the level of the posterior vertebral wall using the rib as a landmark for resecting the rib head without opening the chest. Using the angled microendoscope and curved surgical instruments, the central TDH, located ventral to the spinal canal, can then be safely and effectively resected without spinal cord retraction.

Introduction: The risk factors for the development of progressive segment degeneration (PSD) after decompression surgery are still unknown. In this study, the risk factors for PSD in patients who undergo decompression surgery for lumbar spinal stenosis with and without coexisting spondylolisthesis and scoliosis were examined, focusing on decompression and non-decompression segments.

Methods: We reviewed the data of patients with >5 years of postoperative follow up. Radiographic PSD was defined as either the development of an anterolisthesis or retrolisthesis of >3 mm or a decrease in disc height of >3 mm during the 5-year follow up. On the basis of intervertebral segments, the association between PSD and other preoperative clinical findings was analyzed.

Results: Overall, 840 lumbar segments (L1-L2 to L5-S1) in 168 patients, with a mean age of 69.5±9.2 years, met the inclusion criteria. PSD was observed in 162 (19.3%) lumbar segments. A logistic regression model identified that Cobb angle ≥10° (OR 2.53, 95% CI 1.50-4.24), spondylolisthesis ≥3 mm (OR 4.447, 95% CI 2.06-9.58), and level of segments were more likely to have PSD at the non-decompression level; additionally, lateral listhesis ≥3 mm (OR 2.91, 95% CI 1.08-7.81) was more likely to have PSD in the decompression segments. In clinical outcomes in patients with PSD at baseline and the 5-year follow-up, no significant difference was found.

Conclusions: Even though PSD does not correlate with worsening symptoms, our study confirms that a higher degree of pre-existing disc degeneration is indicative of a higher PSD in 5 years.

Introduction: Sacral perineural cysts are rarely symptomatic; however, they may occasionally cause various symptoms. As the patient exhibits multiple cysts, it often becomes difficult to determine if these cysts are symptomatic.

Technical note: Six patients with multiple sacral cysts, identified using magnetic resonance imaging (MRI), were further examined using myelography and computed tomography (CT) immediately and 6-18 h after myelography. Symptomatic cysts were exclusively diagnosed as not enhanced immediately (filling defect sign) but displayed enhancement later (delayed filling sign/retention sign) compared to the subarachnoid space. A minimal laminectomy was performed on the target cyst. The dura and epineurium with the arachnoid of the cyst were then longitudinally incised along the nerve root, and the adhesion at the junction between the cyst and the dura mater was released. The incised epineurium and dura mater were sutured using 6-0 nylon and covered with multiple layers of polyglycolic acid seat and fibrin glue. A suction drain was placed for 1 or 2 days, and the patients were mobilized on postoperative day 1. Symptoms improved in all patients; however, the improvement ratio varied. At an average follow-up of 39 months, no recurrence was observed on the MRI.

Conclusions: This case series reports the diagnostic and surgical methods for multiple sacral perineural cysts and their outcomes. Delayed CT myelography is helpful in diagnosing symptomatic cysts. Moreover, all cysts with filling defect signs or delayed filling/retention signs demonstrated neural adhesions in the neck. Microsurgical fenestration and the release of adhesions are effective for the improvement of symptoms without recurrence.

Introduction: Previous studies have shown that early patient mobility and activity can improve patient outcomes after lumbar fusion procedures. This study aimed to explore the relationship between patient mobility and activity, measured by the Activity Measure for Post-acute Care (AM-PAC) "6-Clicks" assessment and postoperative outcomes in lumbar fusion patients.

Methods: A retrospective review of 306 lumbar fusions (105 with 6-Clicks mobility and 289 with 6-Clicks activity scores) was conducted. Statistical analyses were performed to evaluate the relationship between 6-Clicks scores and postoperative outcomes, such as prolonged length of stay (LOS), nonhome discharge, 30-day emergency department (ED) returns and readmissions, and minimal clinically important difference (MCID) achievement on the PROMIS-PF instrument at 3-12 months postoperatively.

Results: After controlling for age, body mass index, sex, race, number of levels, and preoperative PROMIS-PF, higher 6-Clicks mobility scores decreased the likelihood of 3+ day LOS (OR: 0.72; p=0.010), non-home discharge (OR: 0.68; p<0.001), and 30-day ED return (OR: 0.78; p=0.022) and increased the likelihood of PROMIS MCID achievement (OR: 1.28; p=0.004). The odds of LOS 3+ days, non-home discharge, and ED return for each one-point increase in mobility scores all decreased by 28%, 32%, and 22%, respectively, while the odds of achieving PROMIS MCID for every one-point increase in mobility increased by 28%. After risk adjustment, higher 6-Clicks activity scores were protective against 3+ day LOS (OR: 0.78; p<0.001) and non-home discharge (OR: 0.69; p<0.001).

Conclusions: The AM-PAC 6-Clicks mobility and activity scores hold value as early indicators of prolonged LOS and nonhome discharge, while mobility scores may help identify patients who are at risk for ED returns and who fail to experience clinically significant improvement in physical function. These tools may be used to identify patients requiring additional resources and can inform discussions surrounding patient expectations.

Introduction: After posterior lumbar interbody fusion (PLIF), trabecular bone remodeling (TBR) occurs in the vertebral body. This study aimed to investigate whether imaging findings obtained with PLIF are applicable to lateral lumbar interbody fusion (LLIF).

Methods: A total of 53 cases who underwent one- or two-level LLIF with polyether ether ketone cage and posterior spinal fixation/fusion (PSF) were retrospectively included in this study. TBR, vertebral endplate cyst (VEC), facet union, and pseudarthrosis were investigated on computed tomography (CT) images at 3 months, 1 year, and 2 years postoperatively. Of the 53 patients, 36 (68%) who underwent CT examination at approximately 5 years postoperatively were subanalyzed.

Results: TBR was commonly observed anterior to the cage on CT sagittal images. The TBR-positive rate was 21%, 67%, and 73% at 3 months, 1 year, and 2 years postoperatively, respectively. The 3-month TBR-positive segments showed significantly less VEC (0% vs. 29%, P=0.029) at 1 year postoperatively. The 1-year TBR-positive segments showed a significantly higher facet union rate (83% vs. 57%, P=0.019) and less pseudoarthrosis (0% vs. 13%, P=0.041) at 2 years postoperatively. At 5 years postoperatively, 50% of the 2-year TBR-positive segments turned negative with solid intervertebral bony fusion.

Conclusions: TBR-positive segments had significantly lower future VEC positivity, higher future facet union rates, and lower future pseudarthrosis rates. In LLIF-PSF, TBR suggests the establishment of intervertebral stability and allows consideration of intervertebral biomechanics.

Introduction: Patients with adult spinal deformity (ASD) lean forward with their trunks when walking, even if they can remain upright during static standing. However, it remains unclear which part of the spinal column is involved in forward trunk tilt and the details of the relationships between sagittal alignment during static standing and changes in dynamic parameters during walking. Therefore, this study aimed to clarify the above by analyzing the walking motion of ASD patients using inertial measurement units (IMUs).

Methods: Preoperative ASD patients were included in this study. Dynamic parameters during gait were measured by IMUs attached on the skin at the T1, T12, and S1 spinous processes, thigh, and lower leg. Walking data were divided into three phases of 10 s each (initial, middle, and final), and the average dynamic parameters at each phase were statistically compared. The relationships between the standing radiographic and dynamic parameters in the final phase were evaluated by linear regression analyses.

Results: A total of 34 patients were included in this study. Their mean age was 72 years. The inclination of IMUs on the T1, T12, and S1 and the flexion angle of T12-S1 IMUs significantly increased over time. Pelvic tilt (PT) of standing radiography was positively correlated with the inclination angles of T12 (r²=0.22, p=0.0048) and S1 (r²=0.16, p=0.0178) and the flexion angle of T12-S1 IMUs (r²=0.29, p=0.0011).

Conclusions: This study showed that anteversion of the trunk in patients with ASD is due to an increase in lumbar forward bending and anterior tilt of the pelvis. Lumbar forward bending was significantly correlated with PT on standing radiography. It is important to consider the presence of poorer posture during gait than during standing when we evaluate patients with high PT.

Introduction: In high-grade spinal osteotomy involving large anterior column resection, restoration of the structural integrity of the posterior column at the osteotomy site can reduce postoperative instrumentation failure (IF). This study aimed to describe our technique of posterior strut bone grafting using an en bloc resected vertebral arch, which is useful for posterior column reconstruction after high-grade osteotomies during surgeries for spinal tumor and deformity in the lower lumbar spine.

Technical note: Using a posterior approach, en bloc resection of the targeted vertebral arch was performed in accordance with the surgical technique for total en bloc spondylectomy (TES). The posterior elements in the upper and lower adjacent vertebrae were separated by a significant space after vertebral body resection followed by cage insertion in TES or anterior column osteotomy followed by correction in deformity surgery. To create a new posterior column, the en bloc resected vertebral arch was placed at 90° rotation to bridge the upper and lower vertebral arches. Using this technique, an abundant amount of bone chips made from the resected vertebral elements were placed over the en bloc resected posterior arch as an additional bone graft. The technique was used in three patients who underwent TES for spinal tumors and in one patient who underwent grade 4 osteotomy for adult spinal deformity in the lower lumbar spine. One year after surgery, computed tomography showed that the structural integrity of bony fusion was successfully achieved between the en bloc resected arch and the posterior elements of the adjacent vertebrae in all patients and showed no postoperative IFs.

Conclusions: This bone graft technique created new continuity of the posterior column after high-grade osteotomies in the lower lumbar spine. Bone fusion was achieved in the posterior elements to prevent IF after surgery.