Objective To measure the paraspinal muscle parameters, explore the characteristics of paraspinal muscles, and investigate the influence factors of paraspinal muscle degeneration in healthy people. MethodsEighty-two healthy Chinese people were prospectively recruited between February 2020 and November 2020, including 36 males and 46 females. The age ranged from 21 to 75 years, with a mean of 48.0 years. The height ranged from 150 to 183 cm, with a mean of 165.6 cm. The body mass ranged from 43 to 100 kg, with a mean of 65.4 kg. The body mass index (BMI) ranged from 16.7 to 32.4 kg/m2, with a mean of 23.7 kg/m2. Parameters of the paraspinal muscles (multifidus muscle, erector spinae muscle, and psoas major muscle) at L3, L4, and L5 levels were measured by MRI, including the relative total cross-sectional area (rtCSA), relative fatty cross-sectional area (rfCSA), relative signal intensity (rSI), and fatty infiltration (FI). The differences of paraspinal muscle parameters at different genders and different measurement levels were compared; Pearson or Spearman correlation analysis was used to explore the relationship between paraspinal muscle parameters and age, height, body mass, BMI. Results From L3 to L5 level, the rtCSA and rfCSA of multifidus muscle and psoas major muscle as well as the rfCSA of erector spinae muscle increased, while rtCSA of erector spinae muscle decreased. The FI and rSI of paraspinal muscles increased gradually. The parameters of paraspinal muscles at L4 and L5 levels were significantly different from those at L3 levels (P<0.05). There were significant differences in rtCSA and rfCSA of multifidus muscle, rtCSA, FI, and rSI of erector spinae muscle as well as rtCSA, rfCSA, and FI of psoas major muscle between L4 and L5 levels (P<0.05). Compared with males, the rfCSA and FI of multifidus muscle, FI of erector spinae muscle, and FI of psoas major muscle were significantly higher in females, while the rtCSA of psoas major muscle was significantly lower (P<0.05). Age was significantly negatively correlated with rtCSA of paraspinal muscles (P<0.05), but significantly positively correlated with FI of paraspinal muscles, rfCSA and rSI of multifidus and erector spinae muscles (P<0.05). Height was significantly negatively correlated with rfCSA and FI of paraspinal muscles (P<0.05). ConclusionThe degree of paraspinal muscle degeneration increases gradually along the spine axis from head to tail. Paraspinal muscle degeneration is related to age, height, and gender. The relationship between the body mass, BMI and paraspinal muscle degeneration needs further study.
Objective To review the process of radiographic measurements of sagittal balance and offer reference for the clinical practice. Methods The related literature of spino-pelvic sagittal parameters and their clinical application was reviewed and analyzed from the aspects such as the clinical application, the advantages and disadvantages, and how to use them effectively. Results All parameters have their advantages and disadvantages, and they are influenced by age and race. Sagittal vertical axis can only reflect the global balance, and T1 pelvic angle which accounts for both spinal inclination and pelvic tilt can’t be controlled in the surgery. The correction goal for western people may be not suitable for Chinese. Conclusion The parameters should be used wisely when evaluating the sagittal balance, the global balance and local balance should be considered together and the different groups of people need different correction goals.
ObjectiveTo review the evaluation method of paraspinal muscle and its role in lumbar spine diseases, and offer reference for further research on paraspinal muscles.MethodsThe related literature of paraspinal muscle measurement and its role in lumbar spine diseases was reviewed. The evaluation methods of paraspinal muscle were analyzed from the advantages and disadvantages and the role of paraspinal muscle in lumbar spine diseases was summarized.ResultsRadiographic methods are often used to evaluate the atrophy of paraspinal muscle, mainly including CT and MRI. The cross-sectional area and fatty infiltration of paraspinal muscle are two key parameters. Radiographic methods are reproducible and widely applied, but CT has the disadvantage of radiation exposure, while the cost of MRI is high. Besides, more and more researchers focus on the functional evaluation of paraspinal muscle, which mainly includes surface electromyogram analysis and back muscle strength test. The surface electromyogram analysis can quantitatively measure neuromuscular function, but the results could be affected by many influencing factors. The back muscle strength test is simple, but it lacks standardized posture. The atrophy of paraspinal muscle is related to many lumbar spine diseases, while the results of different researches are different.ConclusionThere are many methods to evaluate paraspinal muscles, but there is no unified standard. The role of paraspinal muscle in lumbar spine diseases need to be further studied.
Objective To review the research progress of upper instrumented vertebra (UIV) selection strategy for long-segment fixation (LSF) in adult degenerative scoliosis (ADS). Methods The relevant domestic and foreign literature in recent years was reviewed, and the selection strategy of sagittal and coronal UIV for LSF in ADS patients, the relationship between UIV selection and proximal junctional kyphosis (PJK) and proximal junctional failure (PJF), the impact of minimally invasive spine surgery on the selection strategy of UIV were summarized. Results LSF can restore the biomechanical balance of the spine and reconstruct the physiological curve of the spine for ADS patients. LSF should be selected for ADS patients with severe scoliosis, vertebral rotation, and severe sagittal imbalance. For patients with poor general condition, UIV can choose the thoracic and lumbar vertebrae to reduce the operation time and intraoperative bleeding, which is conducive to early mobilization and reduce complications; for patients with good general condition, the upper thoracic vertebrae can be considered if necessary, in order to achieve satisfactory long-term effectiveness. However, the lower thoracic vertebra (T9、10) should be selected as much as possible to reduce postoperative complications such as PJK and PJF. In recent years, a new reference marker, the first coronal reverse vertebra was proposed, to guide the selection of UIV. But a large-sample multicenter randomized controlled study is needed to further verify its reliability. Studies have shown that different races and different living habits would lead to different parameters of the spine and pelvis, which would affect the selection of UIV. Minimally invasive surgeries have achieved satisfactory results in the treatment of ADS, but the UIV selection strategy in specific applications needs to be further studied. Conclusion The selection strategy of UIV in LSF has not yet been unified. The selection of UIV in the sagittal plane of the upper thoracic spine, the lower thoracic spine, or the thoracolumbar spine should comprehensively consider the biomechanical balance of the spine and the general condition of the patient, as well as the relationship between the upper horizontal vertebra, the upper neutral vertebra, and the upper end vertebra on the coronal plane.
ObjectiveTo compare the complications and clinical scores of posterior lumbar intervertebral fusion (PLIF) in middle-aged and older patients of different ages, and to assess the risk of complications of PLIF in different ages, providing a reference for clinical treatment.MethodsThe clinical data of 1 136 patients, who were more than 55 years old and underwent PLIF between June 2013 and June 2016, were retrospectively analyzed. According to the age of patients undergoing surgery, they were divided into 3 groups as 55-64 years old, 65-74 years old, and ≥75 years old. The general characteristics, comorbidities, and surgical data of the three groups were compared, with comparison the morbidity of complications. According to the minimal clinical important difference (MCID), the improvement of patient’s pain visual analogue scale (VAS) score and the Oswestry disability index (ODI) score were compared. Univariate logistic regression analysis was used to analyze the difference of complications and the improvement of VAS and ODI scores. Multivariate logistic regression analysis was performed for the risk factors of complications.ResultsThere were significant differences in the number of surgical fusion segments and osteoporosis between groups (P<0.05); there was no significant difference in gender, body mass index, operation time, preoperative American Society of Anesthesiologists (ASA) classification, and comorbidities between groups (P>0.05). All patients were followed up 6-62 months with an average of 27.4 months. Among the results of postoperative complications, there were significant differences in the total incidence of intraoperative complications, systemic complications, minor complications, and the percentage of improvement of ODI score to MCID between groups (P<0.05); but there was no significant difference in the total incidence of complications at the end of long-term follow-up and the percentage of improvement of VAS score to MCID between groups (P>0.05). Univariate logistic regression analysis showed that after adjusting the confounding factors, there were significant differences in intraoperative complications and the percentage of improvement of ODI score to MCID between 55-64 and 65-74 years old groups (P<0.05); systemic complications, minor complications, complications at the end of long-term follow-up, and the percentage of improvement of ODI score to MCID in ≥75 years old group were significantly different from those in the other two groups (P<0.05). Multivariate logistic regression analysis showed that age was a risk factor for systemic complications, minor complications, and complications at the end of long-term follow-up. Except for age, long operation time was a risk factor for intraoperative complications, increased number of fusion segments was a risk factor for systemic complications, the number of comorbidities was a risk factor for minor complications, and osteoporosis was a risk factor for complications at the end of long-term follow-up.ConclusionThe risk of surgical complications is higher in the elderly patients (≥75 years) with lumbar degenerative diseases than in the middle-aged and older patients (<75 years), while the improvements of postoperative VAS and ODI scores were similar. Under the premise of fully assessing surgical indications, PLIF has a positive effect on improving the elderly patients’ quality of life.
Objective To analyze the prospective effect of pre-existing spinal stenosis of adjacent segment on the short-term effectiveness after lumbar fusion surgery. Methods A prospective comparative study was conducted to divide 183 patients with L4-S1 lumbar spinal stenosis who met the selection criteria between July 2015 and December 2017 into two groups according to the status of adjacent segment degeneration (ASD) judged by preoperative disc degeneration and spinal stenosis. There were 98 patients in group A (no degeneration of adjacent segments before operation) and 85 patients in group B (adjacent segments degenerated before operation). There was no significant difference in gender, American Society of Anesthesiologists (ASA) grade, body mass index (BMI), combined spondylolisthesis, and preoperative visual analogue scale (VAS) score of low back pain and leg pain, Japanese Orthopaedic Association (JOA) score, and Oswestry disability index (ODI) score between the two groups (P>0.05); the age of group A was significantly younger than that of group B (t=−3.560, P=0.000). The operation time, intraoperative blood loss, hospitalization stay, and perioperative complications were recorded and compared. The VAS score of low back pain and leg pain, JOA score, and ODI score at last follow-up were used to evaluate the effectiveness. The incidence of ASD after operation was compared between the two groups, and logistic regression was used to analyze the independent risk factors affecting the occurrence of ASD after operation. Results There was no significant difference in operation time, intraoperative blood loss, and hospitalization stay between the two groups (P>0.05). The incidence of perioperative complications in groups A and B was 13.3% and 20.0%, respectively, with no significant difference (χ2=1.506, P=0.220). Two groups of patients were followed up, the follow-up time of groups A and B was (24.9±8.8) months and (24.8±7.8) months, respectively, there was no significant difference (t=0.050, P=0.960). At last follow-up, no adjacent segment disease was found in either group. There was no significant difference in Pfirrmann grade between the two groups at last follow-up (P>0.05), and there was significant difference in Pfirrmann grade between the two groups before operation and at last follow-up (P<0.001). At last follow-up, 21 cases (21.4%) in group A and 53 cases (62.4%) in group B had ASD, with significant difference (χ2=31.652, P=0.000). The main cause of ASD was the severity of adjacent spinal canal stenosis. The clinical scores of the two groups at last follow-up were significantly improved when compared with those before operation (P<0.05). The JOA score of group A was significantly higher than that of group B at last follow-up (P<0.05). In group B, the VAS score of low back pain and ODI score in patients with ASD after operation at last follow-up were significantly higher than those in patients without ASD (P<0.05). logistic regression analysis showed that preoperative pre-existing degeneration and BMI were independent risk factors for ASD after operation (P<0.05). Conclusion Pre-existing mild spinal stenosis in adjacent segment can significantly affect the effectiveness, and can significantly increase the risk of ASD early after operation. The main pathological type of ASD was the severity of adjacent segment spinal stenosis. For preoperative assessment of pre-existing degeneration, we should evaluate the overall degeneration of the adjacent segment of the spinal canal, rather than simply evaluating the degeneration of the adjacent disc and facet joints.