Is minimally invasive surgery a game changer in spinal surgery?

Minimally invasive spine surgery (MISS) has revolutionized the treatment of spinal disorders over the past few decades. This review provides an in-depth analysis of MISS techniques, technologies, outcomes, and future directions. The evolution of MISS techniques-including tubular retractor systems, percutaneous pedicle screw fixation, minimally invasive transforaminal lumbar interbody fusion, lateral lumbar interbody fusion, and endoscopic spine surgery-has expanded the scope of treatable spinal pathologies while minimizing tissue trauma. Technological advancements such as intraoperative navigation, robotics, and augmented reality applications have enhanced precision and capabilities. Clinical evidence supports the efficacy and safety of MISS techniques for various spinal pathologies, demonstrating comparable or superior outcomes to traditional open approaches with reduced tissue trauma, blood loss, and hospital stays. Cost-effectiveness analyses also favor MISS over open techniques. Future directions in MISS include expanding indications, integrating artificial intelligence and machine learning, advancing tissue engineering and biologics, and refining robotic and augmented reality applications. As MISS continues to evolve, it is poised to play an increasingly important role in the treatment of spinal disorders, offering improved patient outcomes with reduced morbidity. However, ongoing rigorous evaluation of new techniques and technologies is crucial to balance potential benefits with associated risks and costs.

The Effect of Transpedicular Injection of Recombinant Human Bone Morphogenetic Protein-2/Beta-Tricalcium Phosphate Carrier on the Prevention of Proximal Junctional Kyphosis in Adult Spinal Deformity Surgery: A Pilot Study.

BACKGROUND AND OBJECTIVES: Several studies have explored strategies to prevent proximal junctional kyphosis (PJK) which is the unresolved issue in adult spinal deformity (ASD) surgery. This study aimed to investigate the preventive effects of upper instrumented vertebrae (UIV) recombinant human bone morphogenetic protein-2 (rhBMP-2) with beta-tricalcium phosphate (ß-TCP) carrier injection on PJK. METHODS: This study was conducted through a retrospective analysis of data collected both prospectively and retrospectively. In the rhBMP-2 group, consisting of 25 patients with ASD, rhBMP-2 along with ß-TCP carrier was administered to the UIV through the pedicle. To minimize time-related bias, control-1 included 66 patients who had undergone ASD surgery by the same surgeon in the year preceding the commencement of the study. Control-2 consisted of 63 patients who had undergone ASD surgery by the same surgeon during the year after the end of the study. The primary outcome is the occurrence of PJK within one year postsurgery, and the secondary outcome is the change in Hounsfield unit of the UIV one year after the surgery. RESULTS: When comparing baseline characteristics with control groups, a significant difference was observed only in body mass index, with control-1 (P = .006) and control-total (control-1 + control-2, P = .026) having a higher body mass index than the study group. In the rhBMP-2 group, there were 3 cases (PJK rate, 12.0%) of PJK, whereas control-1 and control-2 had 26 cases (PJK rate, 39.4%, P = .012) and 20 cases (PJK rate, 31.7%, P = .057), respectively. In the control-total, there were 46 cases (PJK rate, 35.7%, P = .020) of PJK. The UIV that received rhBMP-2 showed a statistically significant increase in Hounsfield unit measurements compared to preoperative values 1 year after surgery (P = .001). CONCLUSION: The transpedicular injection of rhBMP-2/ß-TCP carrier at the UIV significantly contributed to the prevention of PJK and effectively increased trabecular bone density at the UIV.

Efficacy and Safety of Biportal Endoscopic Decompressive Laminectomy in Octogenarians With Severe Lumbar Spinal Stenosis.

BACKGROUND: Lumbar spinal stenosis (LSS) is prevalent among octogenarians, causing significant pain and disability. Surgical intervention is often required because of the ineffectiveness of conservative treatments. This study investigates the efficacy and safety of biportal endoscopic decompressive laminectomy (BED) in octogenarians with severe LSS, evaluating its potential as a minimally invasive surgical option. METHODS: This retrospective study included 107 patients aged 80 years or older who underwent BED for LSS between March 2017 and December 2022. Data were collected from electronic medical records, including demographic information, clinical outcomes, and surgical details. Patients with fractures, infectious spondylitis, herniated discs, and follow-up less than 12 months were excluded. Clinical outcomes were assessed using the visual analog scale, Oswestry Disability Index, European Quality of Life-5 Dimensions, and painDETECT at baseline and at 3, 6, and 12 months after surgery. RESULTS: The mean age of the 107 patients was 84.1 years, with 59% being women. Significant improvements were observed in visual analog scale scores for lower back and lower extremities pain, Oswestry Disability Index, European Quality of Life-5 Dimensions, and painDETECT scores, indicating reduced pain, decreased disability, and enhanced quality of life. There were no significant differences in outcomes between patients aged 80 to 84 and those 85 or older. Surgery-related outcomes such as operation time, blood loss, and complications were similar in both age groups. CONCLUSIONS: BED is a safe and effective treatment for LSS in octogenarians, providing significant pain relief and functional improvement. This minimally invasive technique is also viable for patients older than 85 years, without increased risk of complications, supporting its broader indications in managing LSS in the elderly. CLINICAL RELEVANCE: This study highlights the efficacy and safety of BED for LSS in octogenarians, demonstrating its potential to improve quality of life and function with low risks, making it a feasible option for elderly patients.

Impact of Teriparatide and Denosumab on Clinical and Radiographic Outcomes in Osteoporotic Vertebral Compression Fractures.

Background and Objectives: Osteoporotic vertebral compression fractures (OVCFs) are prevalent among the elderly, often leading to significant pain, morbidity, and mortality. Effective management of underlying osteoporosis is essential to prevent subsequent fractures. This study aimed to compare the clinical and radiographic outcomes of teriparatide and denosumab treatments in patients with OVCFs to determine their relative effectiveness in improving patient outcomes. Materials and Methods: This retrospective study included 78 patients diagnosed with an acute thoracolumbar OVCF who received either teriparatide (35 patients) or denosumab (43 patients) within three months of a fracture. Clinical outcomes were assessed using the visual analog scale (VAS) for back pain, Oswestry disability index (ODI), and EQ-5D quality of life scores at baseline, 6 months, and 12 months. Bone mineral density (BMD) and radiographic outcomes were evaluated initially and at 12 months post-treatment. Results: Both treatment groups demonstrated significant improvements in VAS, ODI, and EQ-5D scores over 12 months. No significant differences were observed between the teriparatide and denosumab groups in terms of clinical outcomes or radiographic measurements at any time point. Fracture union and BMD improvements were similarly observed in both groups. The teriparatide group had a lower baseline BMD, but this did not affect the overall outcomes. Conclusions: Both teriparatide and denosumab are effective in improving clinical and radiographic outcomes in patients with OVCFs. Despite concerns about denosumab's potential to hinder fracture healing, our study found no significant differences between the two treatments. These findings support the use of denosumab for early treatment of OVCFs to prevent subsequent fractures without compromising fracture healing. Further prospective studies are needed to confirm these results.

Comparative Study on the Efficacy of Pregabalin Versus Limaprost in Patients With Lumbar Spinal Stenosis: A Prospective, Randomized Controlled Trial.

BACKGROUND: Patients with Lumbar Spinal Stenosis (LSS) typically complain of back pain and leg pain. These symptoms reduce the quality of life (QoL) and also cause sleep disturbances. This study compares pregabalin and limaprost's efficacy in LSS for pain, disability, QoL, and sleep, aiming to offer insights for medication selection. METHODS: This study was designed as a prospective, randomized, single-center, single-blinded, clinical superiority trial targeting patients with LSS. For 6 weeks, 111 patients per group were administered medication following a standard regimen, after which patient-reported outcomes were measured. The primary outcome was the Visual Analogue Scale (VAS) for back and leg pain, and the secondary outcomes included the Oswestry Disability Index (ODI), European Quality of Life 5 Dimensions (EQ-5D), and sleep quality. RESULTS: After 6 weeks of medication, there were significant improvements over time in the primary outcome, VAS for back pain and leg pain, in both groups, but no significant difference between the 2 groups. Similarly, for the secondary outcomes, ODI and EQ-5D, both groups showed significant improvements, yet there was no significant difference between them. In the subgroup analysis targeting poor sleepers (Pittsburgh sleep quality index, PSQI >5), both groups also exhibited significant improvements in sleep quality, but again, there was no significant difference between the groups. CONCLUSIONS: Efficacy of pregabalin, limaprost in back and leg pain, ODI, EQ-5D, and sleep quality, but there was no significant difference between the 2 groups. Thus, it is advisable to prescribe based on individual drug responses and potential complications.

Transpedicular injection of rhBMP-2 with ß-tricalcium phosphate to reduce the proximal junctional kyphosis after adult spinal deformity correction: preliminary study.

The aim of this preliminary study was to assess the impact of injecting recombinant human bone morphogenetic protein-2 (rhBMP-2) with ß-tricalcium phosphate (ß-TCP) carrier into the uppermost instrumented vertebra (UIV) during surgery to prevent the development of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). The 25 patients from study group had received 0.5 mg rhBMP-2 mixed with 1.5 g ß-TCP paste injection into the UIV during surgery. The control group consisted of 75 patients who underwent surgery immediately before the start of the study. The incidences of PJK and PJF were analyzed as primary outcomes. Spinopelvic parameters and patient-reported outcomes were analyzed as secondary outcomes. Hounsfield unit (HU) measurements were performed to confirm the effect of rhBMP-2 with ß-TCP on bone formation at preoperative and postoperative at computed tomography. PJK and PJF was more occurred in control group than study group (p = 0.02, 0.29, respectively). The HU of the UIV significantly increased 6 months after surgery. And the increment at the UIV was also significantly greater than that at the UIV-1 6 months after surgery. Injection of rhBMP-2 with ß-TCP into the UIV reduced PJK and PJF rates 6 months after surgery with new bone formation.

A Randomized Controlled Trial of Vertebral Body Decompression Procedure Versus Conservative Treatment for Painful Vertebral Compression Fracture.

Background: Traditional treatment modalities for vertebral compression fractures (VCFs) include bed rest, pain medications, muscle relaxants, back braces, and physical therapy. In cases where conservative treatment proves ineffective, a new procedure called core decompression of the vertebral body is explored. Core decompression of the vertebral body has the potential to lower and stabilize the intraosseous pressure, resulting in enhanced blood circulation, which contributes to pain reduction. In this trial, we evaluated the efficacy of core decompression of the vertebral body in patients with painful VCFs compared with conventional conservative treatment. Methods: This prospective randomized controlled trial was conducted at a tertiary education hospital between June 2017 and May 2020. The participants were randomly assigned in a 1:1 ratio to one of two treatment groups: the core decompression group and the conservative treatment group. The primary outcome measure was the visual analog scale (VAS) pain score of the back 3 months after the procedure. Secondary outcome measures included the Oswestry Disability Index (ODI) for lumbar disabilities, the European Quality of Life-5 Dimensions (EQ-5D) score for quality of life, and radiographic outcomes such as changes in compression rate. Results: All patients underwent the assigned intervention (48 core decompression and 50 conservative treatments). At both 1 month and 3 months, there were no significant differences between the core decompression group and conservative treatment group in VAS pain score (adjusted treatment effect: -0.1 and 2.0; 95% confidence interval [CI]: -7.5 to 7.3 and -5.6 to 9.6; p = 0.970 and p = 0.601, respectively). In addition, there were no significant inter-group differences in ODI and EQ-5D scores throughout the follow-up period (p = 0.917 and 0.704, respectively). Conclusion: Core decompression of the vertebral body did not demonstrate any significant improvement in pain and disability compared to conventional conservative treatment.

The Feasibility of Multiple Fixation Points in C2.

STUDY DESIGN: Analysis using three-dimensional simulation software for spinal screw placement and computed tomographic scan images. PURPOSE: To assess the feasibility of achieving multiple (three or four) screw fixation points in C2 vertebra by using a combination of pedicle and laminar screws. OVERVIEW OF LITERATURE: Secure C2 fixation using multiple screws is required or beneficial in some unique cases. However, to the best of our knowledge, there have been no reports analyzing the feasibility of multiple screw fixation in C2. METHODS: We used 1.0-mm interval computed tomographic scan images of 100 patients (50 men and 50 women) and screw trajectory simulation software. The diameter of all screws was set at 3.5 mm, considering its common usage in real surgery. The anatomical feasibility of placing both pedicle and laminar screws on the same side was evaluated. For all feasible sides, the three-dimensional distance between the screw entry points was measured. RESULTS: In 85% of cases, both pedicle and laminar screws could be placed on both sides, allowing for the insertion of 4 screws. In 11% of cases, 2 screws could be placed on one side, while only 1 screw was feasible on the other side, resulting in the placement of 3 screws. In all 181 sides where both types of screws could be inserted, the distance between their entry points exceeded 16.1 mm, which was sufficient to prevent the collision between the screw heads. CONCLUSIONS: C2 vertebra can accommodate three (11%) or four (85%) screws in 96% of cases.

Biportal endoscopic discectomy versus tubular microscopic discectomy for treating single-level lumbar disc herniation in obese patients: a multicenter, retrospective analysis.

PURPOSE: In microscopic lumbar discectomy in obese patients, a correlation is found between the operation time and increase in estimated blood loss according to the increase in body mass index; however, no studies have investigated the outcomes of biportal endoscopic lumbar discectomy in obese patients. Therefore, this study aimed to compare the clinical and radiographic outcomes of microscopic and endoscopic discectomy in obese patients with lumbar herniated discs. METHODS: In this multicenter, retrospective study, clinical and radiological data were compared and analyzed in 73 obese patients with a body mass index of > 30 kg/m2 who underwent microscopic or biportal endoscopic lumbar discectomy. Clinical data on the visual analog scale (VAS), Oswestry disability index (ODI), and EuroQol-5D (EQ-5D) scores were measured, and radiological data were obtained using magnetic resonance imaging (MRI). RESULTS: This study enrolled 43 patients who underwent microscopic discectomy and 30 who underwent biportal endoscopic discectomy. The VAS, ODI, and EQ-5D scores in both groups improved after surgery compared with those before surgery, although there was no difference between the two groups. Although there was a difference in the incidence of recurrent disc herniation confirmed by MRI after surgery, no difference was found in the number of patients requiring surgery between the two groups. CONCLUSION: In obese patients with lumbar disc herniation that was not improved with conservative treatment, no significant clinical or radiological differences in outcomes were noted between microscopic and biportal endoscopic surgery methods. In contrast, minor complications were less common in the biportal group.

Anterior Cervical Discectomy and Fusion Performed Using a CaO-SiO2-P2O5-B2O3 Bioactive Glass Ceramic or Polyetheretherketone Cage Filled with Hydroxyapatite/ß-Tricalcium Phosphate: A Prospective Randomized Controlled Trial.

A CaO-SiO2-P2O5-B2O3 bioactive glass-ceramic (BGS-7) spacer provides high mechanical stability, produces a chemical bond to the adjacent endplate, and facilitates fusion after spine surgery. This prospective, randomized, single-blind, non-inferiority trial aimed to evaluate the radiographic outcomes and clinical efficacy of anterior cervical discectomy and fusion (ACDF) using a BGS-7 spacer for treating cervical degenerative disorders. Thirty-six patients underwent ACDF using a BGS-7 spacer (Group N), and 40 patients underwent ACDF using polyetheretherketone (PEEK) cages filled with a mixture of hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP) for the treatment of cervical degenerative disorders. The spinal fusion rate was assessed 12 months postoperatively using three-dimensional computed tomography (CT) and dynamic radiographs. Clinical outcomes included patient-reported outcome measures, visual analog scale scores for neck and arm pain, and scores from the neck disability index (NDI), European Quality of Life-5 Dimensions (EQ-5D), and 12-item Short Form Survey (SF-12v2). All participants were randomly assigned to undergo ACDF using either a BGS-7 spacer or PEEK cage filled with HA and ß-TCP. The primary outcome was the fusion rate on CT scan image at 12 months after ACDF surgery based on a per-protocol strategy. Clinical outcomes and adverse events were also assessed. The 12-month fusion rates for the BGS-7 and PEEK groups based on CT scans were 81.8% and 74.4%, respectively, while those based on dynamic radiographs were 78.1% and 73.7%, respectively, with no significant difference between the groups. There were no significant differences in the clinical outcomes between the two groups. Neck pain, arm pain, NDI, EQ-5D, and SF-12v2 scores significantly improved postoperatively, with no significant differences between the groups. No adverse events were observed in either group. In ACDF surgery, the BGS-7 spacer showed similar fusion rates and clinical outcomes as PEEK cages filled with HA and ß-TCP.

Risk of fracture according to temporal changes of low body weight changes in adults over 40 years: a nationwide population-based cohort study.

BACKGROUND: Low body weight is associated with an increased risk of fractures. However, the effect of temporal changes in the low body weight status on the risk of fracture remains unknown. This study aimed to evaluate the relationships between temporal changes in low body weight status and the risk of fractures in adults over the age of 40 years. METHODS: This study included data on adults over 40 years old who underwent two biannual consecutive general health examinations between January 1, 2007 and December 31, 2009 extracted from the National Health Insurance Database, a large nationwide population database. Fracture cases in this cohort were monitored from the time of the last health examination to the end of the designated follow-up period (from January 1, 2010 to December 31, 2018) or the participant's death. Fractures were defined as any fracture resulting in hospitalization or outpatient treatment claim after the date of general health screening. The study population was then separated into four groups based on the temporal changes in low body weight status as follows: low body weight to low body weight (L-to-L), low body weight to non-low body weight (L-to-N), non-low body weight to low body weight (N-to-L), and non-low body weight to non-low body weight (N-to-N). The hazard ratios (HRs) for new fractures, depending on weight changes over time, were calculated using Cox proportional hazard analysis. RESULTS: Adults in the L-to-L, N-to-L, and L-to-N groups had a substantially increased risk of fractures after multivariate adjustment (HR, 1.165; 95% confidence interval [CI], 1.113-1.218; HR, 1.193; 95% CI, 1.131-1.259; and HR, 1.114; 95% CI, 1.050-1.183, respectively). Although the adjusted HR was greater in participants who changed into having a low body weight, followed by those with consistently low body weight, those with low body weight remained to have an elevated risk of fracture independent of weight fluctuation. Elderly men (aged over 65 years), high blood pressure, and chronic kidney disease were significantly associated with an increase in fractures (p < 0.05). CONCLUSION: Individuals aged over 40 years with low body weight, even after regaining normal weight, had an increased risk of fracture. Moreover, having a low body weight after having a normal body weight increased the risk of fractures the most, followed by those with consistently low body weight.

A Novel Trajectory of C7 Laminar Screws Determined Using Three-Dimensional Computed Tomography and Surgical Simulation Software: Comparison with a Pre-existing Trajectory.

STUDY DESIGN: Examination using three-dimensional screw trajectory software and computed tomographic scans. PURPOSE: To evaluate the feasibility of a novel trajectory for C7 laminar screws and to compare it with an old trajectory. OVERVIEW OF LITERATURE: The previously reported trajectory of C7 laminar screws has a horizontal direction without a fixed target point. Our new trajectory has a cephalad direction with a fixed target point. METHODS: Computed tomographic scans of a total of 50 male and 50 female patients were utilized. The placement of C7 laminar screws was activated employing the new and old trajectories. The success rate, the causes of failure, and the maximum allowable length of each trajectory were compared. RESULTS: Employing the new trajectory, the success rates of the unilaminar and bilaminar screws were 93% and 83%, respectively, which were significantly better than the old trajectory (80%, p<0.0001 and 70%, p=0.0003). The most prevalent cause of failure was laminar cortical breach followed by facet joint violation. The new trajectory also offered significantly longer maximum allowable screw length in unilaminar (32.5±4.3 mm vs. 26.5±2.6 mm, p<0.001), bilaminar cephalic (29.5±3.8 mm vs. 25.9±2.6 mm, p<0.0001) and bilaminar caudal (33.1±2.6 mm vs. 25.8±3.1 mm, p<0.001) screws than the old trajectory. With the new and old trajectories, 70% vs. 6% of unilaminar, 60% vs. 2% of bilaminar caudal, and 32% vs. 4% of bilaminar cephalic screws could be protracted perfectly into the corresponding lateral mass without any laminar cortical or facet joint violation (p<0.0001). CONCLUSIONS: The novel trajectory possesses a substantially higher success rate, longer maximum allowable screw length, and higher chance to be extended into the lateral mass (a condition known as a lamino-lateral mass screw) than the old trajectory.

Underweight and risk of fractures in adults over 40 years using the nationwide claims database.

We aimed to investigate how underweight affects the incidence of fractures, as well as the influence of cumulative, longitudinal periods of low body mass index (BMI) and changes in body weight on fracture development. Data on adults aged 40-year and over who had three health screenings between January 1, 2007, and December 31, 2009 were used to determine the incidence of new fractures. The hazard ratios (HRs) for new fractures depending on BMI, total cumulative number of underweight, and weight change over time were calculated using Cox proportional hazard analysis. In this study, 15,955 (2.8%) of the 561,779 adults were diagnosed with fractures more than once over three health examinations. The fully adjusted HR for fractures in underweight individuals was 1.173 (95% Confidence interval [CI] 1.093-1.259). Underweight individuals diagnosed only once, twice, or three times had an adjusted HR of 1.227 (95%CI 1.130-1.332), 1.174 (95%CI 1.045-1.319), and 1.255 (95%CI 1.143-1.379), respectively. Although the adjusted HR was higher in adults who consistently had underweight (HR; 1.250 [95%CI 1.146-1.363]), those with underweight had an increased risk of fractures regardless of weight change (HR; 1.171 [95%CI 1.045-1.312], and 1.203[95%CI 1.075-1.346]). Underweight is a risk factor for fractures in adults over the age of 40 years, even if they returned to normal weight.

Development and Validation of a Risk-Prediction Nomogram for Chronic Low Back Pain Using a National Health Examination Survey: A Cross-Sectional Study.

BACKGROUND: Several prognostic factors have been reported for chronic low back pain (CLBP). However, there are no studies on the prediction of CLBP development in the general population using a risk prediction model. This cross-sectional study aimed to develop and validate a risk prediction model for CLBP development in the general population, and to create a nomogram that can help a person at risk of developing CLBP to receive appropriate counseling on risk modification. METHODS: Data on CLBP development, demographics, socioeconomic history, and comorbid health conditions of the participants were obtained through a nationally representative health examination and survey from 2007 to 2009. Prediction models for CLBP development were derived from a health survey on a random sample of 80% of the data and validated in the remaining 20%. After developing the risk prediction model for CLBP, the model was incorporated into a nomogram. RESULTS: Data for 17,038 participants were analyzed, including 2693 with CLBP and 14,345 without CLBP. The selected risk factors included age, sex, occupation, education level, mid-intensity physical activity, depressive symptoms, and comorbidities. This model had good predictive performance in the validation dataset (concordance statistic = 0.7569, Hosmer-Lemeshow chi-square statistic = 12.10, p = 0.278). Based on our model, the findings indicated no significant differences between the observed and predicted probabilities. CONCLUSIONS: The risk prediction model presented by a nomogram, which is a score-based prediction system, can be incorporated into the clinical setting. Thus, our prediction model can help individuals at risk of developing CLBP to receive appropriate counseling on risk modification from primary physicians.

The Impact of Persistent Low Weight Status on the Occurrence of Vertebral Fractures: A Nationwide Population-Based Cohort Study.

BACKGROUND: Although, being underweight is commonly associated with osteoporosis and sarcopenia, its association with vertebral fractures (VFs), is less well researched. We investigated the influence of cumulative, chronic periods of low weight and changes in body weight on VF development. METHODS: We used a nationwide, population-based database with data on people (> 40 years) who attended three health screenings between January 1, 2007, and December 31, 2009 to assess the incidence of new VFs. Cox proportional hazard analyses were used to establish the hazard ratios (HRs) for new VFs based on the degree of body mass index (BMI), the cumulative numbers of underweight participants, and temporal change in weight. RESULTS: Of the 561,779 individuals in this analysis, 5,354 (1.0%) people were diagnosed three times, 3,672 (0.7%) were diagnosed twice, and 6,929 (1.2%) were diagnosed once. The fully adjusted HR for VFs in underweight individuals was 1.213. Underweight individuals diagnosed only once, twice, or three times had an adjusted HR of 0.904, 1.443, and 1.256, respectively. Although the adjusted HR was higher in adults who were consistently underweight, there was no difference in those who experienced a temporal change in body weight. BMI, age, sex, and household income were significantly associated with VF incidence. CONCLUSION: Low weight is a risk factor for VFs in the general population. Given the significant correlation between cumulative periods of low weight and the risk of VFs, it is necessary to treat underweight patients before a VF to prevent its development and other osteoporotic fractures.

Feasibility and safety of a CaO-SiO2-P2O5-B2O3 bioactive glass ceramic spacer in posterior lumbar interbody fusion compared with polyetheretherketone cage: a prospective randomized controlled trial.

PURPOSE: The CaO-SiO2-P2O5-B2O3 glass-ceramic (BGS-7) spacer is a recently developed spacer that shows chemical bonding to bone with high mechanical stability. Further, this spacer achieves similar results to those of titanium cages. However, evidence regarding the advantages of the BGS-7 spacer is weak compared to polyetheretherketone (PEEK) cage. A randomized controlled trial is therefore warranted. The purpose of this study was to compare the radiographic and clinical efficacies and safety of the BGS-7 spacer compared to those of the PEEK cage in patients who underwent posterior lumbar interbody fusion (PLIF). METHODS: The 54 participants who required one- or two-level PLIF due to lumbar degenerative disorders were randomly assigned to receive a BGS-7 spacer or PEEK cage. Visual analog scale (VAS), Oswestry Disability Index (ODI), European Quality of Life-5 Dimensions (EQ-5D), and painDETECT score were evaluated before surgery and at 3, 6, and 12 months after surgery. The fusion rate, degree of osteolysis, cage migration, and subsidence around the cage (spacer) were evaluated on computer tomography (CT) images at 12 months after surgery. RESULTS: The 12-month fusion rates were 77.8% in the BGS-7 spacer group and 81.0% in the PEEK cage group, with no significant difference (p = 0.807). The result regarding the non-inferiority of BGS-7 spacer was inconclusive. The linear mixed model showed no significant intervention effect in VAS, ODI, EQ-5D, and painDETECT score at the 3-, 6-, or 12-month follow-up. In addition, we found no significant between-group differences in the extent of osteolysis, spacer migration. However, the subsidence around the cage was significantly lower in the BGS-7 spacer group. CONCLUSIONS: This trial found similar fusion rates, and clinicoradiographic outcomes between the BGS-7 spacer and PEEK cage for PLIF. However, the non-inferiority was inconclusive. Safety concerns regarding fracture and migration of the BGS-7 spacer must be considered. Thus, the BGS-7 spacer design for PLIF surgery should be modified before further clinical use.

Determining a Cutoff Value for Hand Grip Strength to Predict Favorable Outcomes of Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective review. OBJECTIVES: To establish a cutoff value for hand grip strength and predict the favorable outcomes of adult spinal deformity surgery. SUMMARY OF BACKGROUND DATA: Hand grip strength (HGS) has been suggested to predict surgical outcomes in various fields, including adult spinal deformity (ASD). However, to the best of our knowledge, no study has established a cutoff value for HGS in patients with ASD. METHODS: This study included 115 female patients who underwent reconstructive spinal surgery for ASD between September 2016 and September 2020. HGS was measured preoperatively. The Oswestry Disability Index (ODI), EuroQOL-5-dimension (EQ-5D), and visual analog scale (VAS) scores for back pain were all recorded both before and after surgery. Patients were dichotomized either into favorable or unfavorable outcome groups using an ODI cutoff score of 22 at 1 year after surgery. Multivariate logistic regression analysis was done to identify significant factors leading to favorable outcomes. A receiver operating characteristic (ROC) curve was drawn to define the cutoff value of HGS for favorable outcomes. RESULTS: Multivariate logistic regression analysis showed that HGS is significantly associated with favorable surgical outcomes in ASD (P = .031). The ROC curve suggested a cutoff value of 14.20 kg for HGS (area under the curve (AUC) = .678, P = .013) to predict favorable surgical outcomes in ASD. The surgical complications were not significantly affected by HGS. CONCLUSION: The HGS of patients with ASD can be interpreted with a cutoff value of 14.20 kg. Patients with HGS above this cutoff value showed superior surgical outcomes at 1 year after surgery compared to those below this cutoff value.

Biportal endoscopic versus microscopic discectomy for lumbar herniated disc: a randomized controlled trial.

BACKGROUND CONTEXT: Biportal endoscopic discectomy has been frequently performed in recent years and has shown acceptable clinical outcomes. However, evidence regarding its efficacy and safety remains limited. PURPOSE: This study aimed to compare the clinical efficacy and safety of biportal endoscopic with that of open microscopic discectomy in patients with single-level herniated lumbar discs. STUDY DESIGN: Prospective, randomized, multicenter, open-label, assessor-blind, non-inferiority controlled trial. PATIENT SAMPLE: Sixty-four participants suffering from low back and leg pain with a single-level herniated lumbar disc and required discectomy. OUTCOME MEASURES: Outcomes were assessed with the use of patient-reported outcome measures (PROMs), visual analog scale (VAS) pain score for surgical site, low back and lower extremity, Oswestry Disability Index (ODI) for lumbar disabilities, European Quality of Life-5 Dimensions value for quality of life, and painDETECT for neuropathic pain. Surgery-related outcomes such as hospital stay, operation time, and opioid usage were collected. Adverse events occurring during the follow-up period were also noted. METHODS: All participants were randomly assigned in a 1:1 ratio to undergo biportal endoscopic (biportal group) or microscopic discectomy (microscopy group). The primary outcome was the difference in ODI scores at 12-months post surgically based on a modified intention-to-treat strategy, with a non-inferiority margin of 12.8 points. The secondary outcomes included PROMs, surgery-related outcomes, and adverse events. RESULTS: The ODI score at the 12-month follow-up was 11.97 in the microscopy group and 13.89 in the biportal group (mean difference, 1.92; 95% confidence interval [CI], -3.50 to 7.34), showing the non-inferiority of biportal group. The results for the secondary outcomes were similar to those for the primary outcome. Creatinine phosphokinase ratios were low in the biportal group. Early surgical site pain was slightly lower in the biportal group (mean difference of VAS pain score at 48-hr, -0.98; 95% CI, -1.77 to -0.19). Adverse events including reoperation showed no significant difference between the groups. CONCLUSION: Biportal endoscopic discectomy was non-inferior to microscopic discectomy over a 12 month period. Biportal endoscopic discectomy is suggested to be a relatively safe and effective surgical technique with the slight advantage of reduced muscle damage. However, the clinical implications of surgical site pain should be carefully considered.

Influence of Handgrip Strength and Paraspinal Muscles' Volume on Clinical Outcomes in the Patients With Each Sagittal Imbalance and Lumbar Spinal Stenosis.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To compare handgrip strength (HGS), paraspinal muscles' (PSM) volume, and their effects on clinical symptom severity between the patients with sagittal imbalance (SI) and symptomatic lumbar spinal stenosis (LSS). METHODS: A total of 54 paired consecutive patients with SI and LSS were enrolled after propensity score matching. Preoperative HGS, cross-sectional area (CSA) of psoas (PS) and multifidus (MF) muscles, and patient-reported measures, including visual analog scale (VAS) for back/ leg pain, Oswestry Disability Index (ODI), and EuroQOL (EQ-5D) were compared between both groups. Within each SI and LSS group, patient-reported measures were compared between high and low HGS subgroups. The correlation of HGS and CSA of PSMs to patient-reported measures was evaluated. RESULTS: There was no difference in HGS between 2 groups, however, the CSA of PS and MF muscles in SI group was significantly lower than those in LSS group. Patients with low HGS showed inferior results for ODI and EQ-5D, compared to those with high HGS subgroup in both SI and LSS groups. HGS and CSA of MF muscle were correlated with ODI in both groups. CONCLUSIONS: There was no significant difference between the SI and LSS groups in HGS, however, PSMs' volume in SI group were significantly lower than those in LSS group. Therefore SI would be associated with loss of localized muscle mass in back area, rather than global skeletal muscle weakness. HGS and PSMs' volume were adversely associated with functional status in SI and LSS patients.

Recent Updates on Minimally Invasive Spine Surgery: Techniques, Technologies, and Indications.

A number of minimally invasive spine surgeries (MISSs) have been developed to address the drawbacks of open spine surgery. Their advantages include small skin incisions, reduction in tissue damage, quick recovery, and short hospital stay. However, the clinical outcomes are comparable to open surgery. There was a cap on the number of indications that could be set for all spinal illnesses. The indications for MISSs have been expanding owing to mechanical and technological advances in medical equipment. Thus, this review presents the various MISSs developed to date, surgical indications, surgical techniques, and their advantages and disadvantages.