Effectiveness of vancomycin powder for preventing postoperative spinal infection.

OBJECTIVE: This study aimed to assess the effectiveness of Vancomycin Power (VP) and the occurrence of resistant organisms after four-year of routine VP use. METHODS: The study included 1063 patients who underwent posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) between January 2010 and February 2020. Intrawound VP was applied to all instrumented fusions starting in January 2016. The patients were divided into two groups: those who did not apply VP (non-VP) (n = 605) between 2010 and 2015, and those who did apply VP (VP) (n = 458) between 2016 and 2020. The baseline characteristics, clinical symptoms, infection rate, and causative organisms were compared between the two groups. RESULTS: The rate of PSI was not significantly different between the non-VP group (1.32 %, n = 8) and the VP group (1.09 %, n = 5). Although adjusted by diabetes mellitus, VP still did not show statistical significance (OR = 0.757 (0.245-2.345), p = 0.630). There were no critical complications that were supposed to relation with vancomycin powder. In the 13 cases of PSI, seven pathogens were isolated, with a gram-negative organism identified in the non-VP group. However, the type of organism was not significantly different between the two groups. CONCLUSIONS: The use of intrawound VP may not affect the PSI and occurrence of resistant organism and may not cause critical complications. Therefore, clinicians may decide whether to use VP for preventing PSI not worrying about its safety.

Lumbar radiculopathy and fracture risk: A Korean nationwide population-based cohort study.

INTRODUCTION: Lumbar radiculopathy is a common disease with a high economic burden, and fractures in adults are a significant public health problem. However, studies of the relationship between lumbar radiculopathy and fractures are scarce. We investigated the fracture risk in patients with lumbar radiculopathy. METHODS: This nationwide retrospective cohort study identified 815,101 patients with lumbar radiculopathy and randomly matched individuals without lumbar radiculopathy (1:1) who were included in the Korean National Health Insurance System in 2012. Cox proportional hazards regression analyses were performed to calculate the hazard ratio (HR) for fracture risk in patients with lumbar radiculopathy. RESULTS: The study included 301,347 patients with lumbar radiculopathy and matched 289,618 individuals without lumbar radiculopathy. Compared to individuals without lumbar radiculopathy, patients with lumbar radiculopathy had a 27 % increased fracture risk (adjusted HR = 1.27, 95 % confidence interval = 1.24-1.31). The Kaplan-Meier plot showed a significantly higher fracture incidence in patients with lumbar radiculopathy than in individuals without lumbar radiculopathy at all times. CONCLUSION: Lumbar radiculopathy is significantly associated with fracture risk.

Incidence and Risk Factors for Wound Revision after Surgical Treatment of Spinal Metastasis: A National Population-Based Study in South Korea.

Wound complications are commonly seen after surgeries for metastatic spine tumors. While numerous studies have pinpointed various risk factors, there is ongoing debate. Therefore, this study aimed to verify various factors that are still under debate utilizing the comprehensive Korean National Health Insurance Service database. We identified and retrospectively reviewed a cohort of 3001 patients who underwent one of five surgical treatments (corpectomy, decompression and instrumentation, instrumentation only, decompression only, and vertebroplasty) for newly diagnosed spinal metastasis between 2009 and 2017. A Cox regression analysis was performed to determine the risk factors. A total of 197 cases (6.6%) of wound revision were found. Only the surgical method and Charlson comorbidity index were significantly different between the group that underwent wound revision and the group that did not. Regarding surgical methods, the adjusted hazard ratios for decompression only, corpectomy, instrumentation and decompression, and instrumentation only were 1.3, 2.2, 2.2, and 2.4, with these ratios being compared to the vertebroplasty group (p for trend = 0.02). In this regard, based on a sizable South Korean cohort, both surgical methods and medical comorbidity were found to be associated with the wound revision rate among spinal surgery patients for spinal metastasis.

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.

Underweight as a risk factor for vertebral fractures in the South Korean population.

BACKGROUND CONTEXT: Being underweight is a known risk factor for osteoporosis and sarcopenia that is strongly associated with vertebral fractures, particularly in the elderly. Being underweight can accelerate bone loss, contribute to impaired coordination, and increase fall risk in the elderly and the general population. PURPOSE: This study aimed to identify the degree of underweight as a risk factor for vertebral fractures in the South Korean population. STUDY DESIGN: Retrospective cohort study based on national health insurance database. PATIENT SAMPLE: Participants were included from nationwide regular health check-ups conducted by the Korean National Health Insurance Service in 2009. Participants were followed up from 2010 to 2018 to identify the incidence of newly developed fractures. OUTCOME MEASURES: The incidence rate (IR) was defined as the incident per 1,000 person-years (PY). Vertebral fracture development risk was analyzed using Cox proportional regression analysis. Subgroup analysis was performed based on several factors, including age, sex, smoking status, alcohol consumption, physical activity, and household income. METHODS: Based on body mass index, the study population was categorized into normal weight (18.50-22.99 kg/m2), mild underweight (17.50-18.49 kg/m2), moderate underweight (16.50-17.49 kg/m2), and severe underweight (<16.50 kg/m2) groups. Cox proportional hazards analyses were performed to calculate the hazard ratios for vertebral fractures based on the degree of underweight with respect to normal weight to identify the associated risk. RESULTS: This study evaluated 962,533 eligible participants, of whom 907,484 were classified as normal weight, 36,283 as mild underweight, 13,071 as moderate underweight, and 5,695 as severe underweight. The adjusted hazard ratio of vertebral fractures increased as the degree of underweight increased. Severe underweight was associated with a higher likelihood of vertebral fracture. The adjusted hazard ratio was 1.11 (95% confidence interval [CI], 1.04-1.17) in the mild underweight group, 1.15 (1.06-1.25) in the moderate underweight group, and 1.26 (1.14-1.40) in the severe underweight group when compared with the normal weight group. CONCLUSIONS: Underweight is a risk factor for vertebral fractures in the general population. Furthermore, severe underweight was associated with a higher risk of vertebral fractures, even after adjustment for other factors. Clinicians could provide real-world evidence that being underweight carries the risk of vertebral fractures.

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.

Computed Tomography Evaluation of Percutaneous Pedicle Screws Inserted during Minimally Invasive Transforaminal Lumbar Interbody Fusion: Long-term Follow-up Results of Screw Violation.

Background: To evaluate the accuracy of percutaneous pedicle screw (PPS) insertion in degenerative lumbar disease treated with minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and to analyze risk factors and long-term clinical outcomes of screw violation. Methods: Sixty-two consecutive patients (262 screws) were included. Based on postoperative computed tomography (CT) axial images, a PPS that perforated out of the pedicle was classified into a violation group, while screws surrounded by pedicular cortical bone were classified into a correct group. A logistic regression model was used for risk factor analysis of violation. We also observed the long-term clinical outcomes using the Oswestry disability index and visual analog scale. Results: Of the 262 screws, 14 (5.3%) were considered to be violated (10 medial violations and 4 lateral violations). All violations of S1 and L5 were in the medial direction. In contrast, entire violations of L4 were always lateral and of the 2 violations of L3, one was lateral and the other was medial. There were no cases of superior or inferior violation. The mean pedicle convergence angle (CA) was significantly higher in the violation group (mean ± standard deviation, 27.0° ± 6.2°) than in the correct group (21.7° ± 5.4°). There were no significant differences according to vertebral rotational angle, body mass index, bone mineral density, and surgical timing (learning curve) between the two groups. Logistic regression analyses demonstrated that a high CA was a significant risk factor for pedicle wall violation (p = 0.002). There were no significant differences in clinical or radiographic results between the two groups in 60 patients who were followed up for more than 1 year and in 40 patients who were followed up for more than 5 years. There were 2 patients who required reoperation to replace a screw due to leg pain. Conclusions: With PPS insertion during MI-TLIF, the rate of pedicle violation was 5.3% (14/262). An understanding of the anatomical characteristics of each vertebra and the unique structures of the patient is essential to prevent pedicle violations. Even in the violation group, PPS fixation was found to be a safe and useful procedure with successful long-term radiographic and clinical outcomes.

Is Routine Use of Drain Really Necessary for Posterior Lumbar Interbody Fusion Surgery? A Retrospective Case Series with a Historical Control Group.

STUDY DESIGN: A retrospective case-control study. OBJECTIVES: The usefulness of a drain in spinal surgery has always been controversial. The purposes of this study were to determine the incidence of hematoma-related complications after posterior lumbar interbody fusion (PLIF) without a drain and to evaluate its usefulness. METHODS: We included 347 consecutive patients with degenerative lumbar disease who underwent single- or double-level PLIF. The participants were divided into 2 groups by the use of a drain or not; drain group and no-drain group. RESULTS: In 165 cases of PLIF without drain, there was neither a newly developed neurological deficit due to hematoma nor reoperation for hematoma evacuation. In the no-drain group, there were 5 (3.0%) patients who suffered from surgical site infection (SSI), all superficial, and 17 (10.3%) patients who complained of postoperative transient recurred leg pain, all treated conservatively. Days from surgery to ambulation and length of hospital stay (LOS) of the no-drain group were faster than those of the drain group (P < 0.001). In a multiple regression analysis, a drain insertion was found to have a significant effect on the delayed ambulation and increased LOS. No significant differences existed between the 2 groups in additional surgery for hematoma evacuation, or SSI. CONCLUSIONS: No hematoma-related neurological deficits or reoperations caused by epidural hematoma and SSI were observed in the no-drain group. The no-drain group did not show significantly more frequent postoperative complications than the drain use group, hence the routine insertion of a drain following PLIF should be reconsidered carefully.

Cumulative Burden of Being Underweight Increases the Risk of Hip Fracture: A Nationwide Population-Based Cohort Study.

(1) Background: Being underweight is a known risk factor for hip fractures. However, it is unclear whether the cumulative underweight burden affects the incidence of hip fractures. Therefore, we explored the effect of the cumulative underweight burden on the development of hip fractures; (2) Methods: In a cohort of adults aged 40 years and older, 561,779 participants who were not underweight and had no hip fractures from 2007 to 2009 were identified. The risk of hip fracture from the time of the last examination to December 2018 according to the cumulative burden of being underweight (based on 0 to 3 examinations) was prospectively analyzed; (3) Results: During follow-up (mean 8.3 ± 0.8 years), the prevalence of newly diagnosed hip fractures was 0.2%, 0.4%, 0.5%, and 0.9% among those with 0, 1, 2, and 3 cumulative underweight, respectively. The adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of groups meeting the diagnostic criteria for underweight 1, 2, and 3 compared to 0 were 2.3 (1.6−3.3), 2.9 (1.8−4.5), and 4.5 (3.4−6.1), respectively (p for trend < 0.01); (4) Conclusions: The risk of hip fracture increased as the burden of underweight accumulated.

Management of Osteoporotic Vertebral Fracture: Review Update 2022.

A vertebral fracture is the most common type of osteoporotic fracture. Osteoporotic vertebral fractures (OVFs) cause a variety of morbidities and deaths. There are currently few "gold standard treatments" outlined for the management of OVFs in terms of quantity and quality. Conservative treatment is the primary treatment option for OVFs. The treatment of pain includes short-term bed rest, analgesic medication, anti-osteoporotic medications, exercise, and a brace. Numerous reports have been made on studies for vertebral augmentation (VA), including vertebroplasty and kyphoplasty. There is still debate and controversy about the effectiveness of VA in comparison with conservative treatment. Until more robust data are available, current evidence does not support the routine use of VA for OVF. Despite the fact that the majority of OVFs heal without surgery, 15%-35% of patients with an unstable fracture, persistent intractable back pain, or severely collapsed vertebra that causes a neurologic deficit, kyphosis, or chronic pseudarthrosis frequently require surgery. Because no single approach can guarantee the best surgical outcomes, customized surgical techniques are required. Surgeons must stay current on developments in the osteoporotic spine field and be open to new treatment options. Osteoporosis management and prevention are critical to lowering the risk of future OVFs. Clinical studies on bisphosphonate's effects on fracture healing are lacking. Teriparatide was intermittently administered, which dramatically improved spinal fusion and fracture healing while lowering mortality risk. According to the available literature, there are no standard management methods for OVFs. More multimodal approaches, including conservative and surgical treatment, VA, and medications that treat osteoporosis and promote fracture healing, are required to improve the quality of the majority of guidelines.

Comparison of minimally invasive and open TLIF outcomes with more than seven years of follow-up.

Background: Few studies directly comparing minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF) and open TLIF offering long-term follow-up data have been performed to date. Therefore, we sought to compare mid- to long-term outcomes between these two surgical approaches. Methods: This was a retrospective data analysis of two surgical groups. We analyzed the details of 97 patients with degenerative lumbar disease who were treated with MI TLIF (n = 55) or open TLIF (n = 42) between 2011-2014 and had at least seven years of follow-up data available. Peri- and postoperative outcomes were compared. To evaluate rates of adjacent segment disease (ASD) and revisions, frequencies of radiologic, symptomatic, and operative ASD were analyzed accordingly. Results: In terms of clinical outcome, the Oswestry Disability Index and visual analog scale scores were significantly reduced, with no difference between the groups. However, data for several peri- and postoperative outcomes, including perioperative blood loss, ambulation day, hospital stay, and operation time, varied in a manner favoring the MI TLIF group (P < 0.05). Rates of radiologic ASD and symptomatic ASD were significantly higher in the open TLIF group beginning at five years of follow-up (P < 0.05), while the rate of operative ASD and the revision rate were similar between the groups. Other long-term outcomes, including fusion rate and complications, remained similar between the two groups at 7 years. Conclusion: Patients undergoing MI TLIF showed favorable immediate postoperative outcomes and less radiographic ASD. However, the rates of fusion and operative ASD remained similar between the two groups after 7 years of follow-up.

Incidence of hip fracture in underweight individuals: a nationwide population-based cohort study in Korea.

BACKGROUND: Hip fracture is a major public health problem worldwide and being underweight is a risk factor for fractures. Few studies have investigated the association between being underweight and hip fracture in the general population. The present study investigated the incidence of hip fracture in a large population cohort based on detailed information about the degree of underweight. METHODS: A nationwide retrospective cohort study of adults ≥40 years of age included 962,533 subjects who were not overweight or obese in 2009. The incidence and risk of hip fracture occurring between 2010 and 2018 was assessed based on the degree of underweight. Based on body mass index (BMI), the study population was categorized into normal (18.50-22.99 kg/m2 ), mild (17.00-18.49 kg/m2 ), moderate (16.00-16.99 kg/m2 ), and severe underweight (<16.00 kg/m2 ) groups. Cox proportional hazards analyses were performed to calculate the hazard ratio (HR) for the hip fracture based on the degree of underweight in reference to the normal weight. RESULTS: Compared with subjects who were normal weight, those who were classified as mild underweight (1.03/1000 person-years (PY) increase in incidence rate (IR); adjusted HR (aHR) 1.61; 95% confidence interval (CI) 1.48-1.76), moderate underweight (2.04/1000 PY increase in IR; aHR 1.85; 95% CI 1.65-2.08), or severe underweight (4.58/1000 PY increase in IR; aHR 2.33; 95% CI 2.03-2.66) were at significantly increased risk of hip fracture. CONCLUSIONS: The severity of underweight was significantly associated with risk of hip fracture. The subdivision of underweight helps to estimate fracture risk more accurately.

Severity of underweight and risk of fracture: a Korean nationwide population-based cohort study.

Underweight is an important modifiable risk factor for fractures. However, there have been few large cohort studies regarding the relationship between underweight and fracture in the general population. We investigated the risk of fracture development according to underweight severity in a large population cohort. This nationwide cohort study included 2,896,320 people aged ≥ 40 years who underwent national health checkups in 2009 and were followed up to identify the incidence of fracture until December 31, 2018. After applying the exclusion criteria that included overweight and obese individuals, the study population was divided according to body mass index (BMI) into normal weight (18.5 ≤ BMI < 23.0), mild underweight (17.5 ≤ BMI < 18.5), moderate underweight (16.5 ≤ BMI < 17.5), and severe underweight (BMI < 16.5) groups. Cox proportional hazards regression analyses were performed to calculate the hazard ratios for risk of fracture according to underweight severity. Severely underweight participants had a 28% increased fracture risk (adjusted hazard ratio [HR] 1.28, 95% confidence interval [CI] 1.20-1.37) compared with those of normal weight. In addition, fracture risk was increased by 14% in individuals with moderate underweight (adjusted HR 1.14, 95% CI 1.08-1.19) and 9% in those with mild underweight (adjusted HR 1.09, 95% CI 1.06-1.13). The severity of underweight was significantly associated with risk of fracture.

Clinical differences between delayed and acute onset postoperative spinal infection.

ABSTRACT: Spine surgeons often encounter cases of delayed postoperative spinal infection (PSI). Delayed-onset PSI is a common clinical problem. However, since many studies have investigated acute PSIs, reports of delayed PSI are rare. The purpose of this study was to compare the clinical features, treatment course, and prognosis of delayed PSI with acute PSI.Ninety-six patients diagnosed with postoperative spinal infection were enrolled in this study. Patients were classified into 2 groups: acute onset (AO) within 90 days (n = 73) and delayed onset (DO) after 90 days (n = 23). The baseline data, clinical manifestations, specific treatments, and treatment outcomes were compared between the 2 groups.The history of diabetes mellitus (DM) and metallic instrumentation at index surgery were more DO than the AO group. The causative organisms did not differ between the 2 groups. Redness or heat sensation around the surgical wound was more frequent in the AO group (47.9%) than in the DO group (21.7%) (P = .02). The mean C-reactive protein levels during infection diagnosis was 8.9 mg/dL in the AO and 4.0 mg/dL in the DO group (P = .02). All patients in the DO group had deep-layer infection. In the DO group, revision surgery and additional instrumentation were required, and the duration of parenteral antibiotic use and total antibiotic use was significantly longer than that in the AO group. Screw loosening, disc space collapse, and instability were higher in the DO group (65.2%) than in the AO group (41.1%) (P = .04). However, the length of hospital stay did not differ between the groups.Delayed-onset PSI requires more extensive and longer treatment than acute-onset surgical site infection. Clinicians should try to detect the surgical site infection as early as possible.

Changes in Underweight Status and Risk of Hip Fracture: A Korean Nationwide Population-Based Cohort Study.

Being underweight is associated with a high risk of hip fracture. However, the impact of change in underweight status on the risk of hip fracture is unknown. This study is performed to investigate the relationship between change in underweight status and risk of hip fracture. This study included 1,713,225 subjects aged ≥40 years who underwent two consecutive national health screenings between 2007 and 2009. We prospectively assessed the risk of hip fracture between 2010 and 2018 according to changes in underweight status. We divided the participants into four groups according to the change in underweight status: consistent non-underweight (non-underweight to non-underweight), became non-underweight (underweight to non-underweight), became underweight (non-underweight to underweight), and consistent underweight (underweight to underweight). Compared with the consistent non-underweight group, the became non-underweight (0.74/1000 person years (PY) increase in incidence rate (IR); adjusted hazard ratio (HR) 1.72; 95% confidence interval (CI) 1.42−2.07), became underweight (1.71/1000 PY increase in IR; adjusted HR 2.22; 95% CI 1.96−2.53), and consistent underweight (1.3/1000 PY increase in IR; adjusted HR 2.18; 95% CI 1.89−2.53) groups had a significantly increased risk of hip fracture (p < 0.001). Change in underweight status was significantly associated with a risk of hip fracture.

Associations of walking and resistance training with chronic low back pain in older adults: A cross-sectional analysis of Korean National Health and Nutrition Examination Survey data.

ABSTRACT: Physical activities, such as resistance training and walking, are known to be effective against chronic low back pain (CLBP). However, few studies have examined the associations of walking and resistance training with CLBP in the general older population. Therefore, this study analyzed these relationships in the older Korean population (aged ≥65 years), with the goal of determining which exercise is better for CLBP.This cross-sectional study analyzed Korean National Health and Nutrition Examination Survey data for the period 2012 to 2015. The Korean National Health and Nutrition Examination Survey, which provides representative data for the Korean population, uses a clustered, multistage, random sampling method with stratification based on geographic area, age, and sex. Three multiple logistic regression models were generated in this study to determine the associations of walking and resistance training with CLBP.A total of 5233 participants were enrolled, 3641 (69.6%) of whom were free from CLBP; the remaining 1592 (30.4%) had CLBP. 78.4% and 64.8% of the non-CLBP and CLBP group patients, respectively, walked at least once a week. Also, 23.5% and 11.6% of the participants in the non-CLBP and CLBP groups, respectively, engaged in resistance training at least once a week. In the multiple logistic regression analysis, which was adjusted for all potential confounders, walking was significantly associated with a lower risk of CLBP (1-2d/wk: odds ratio [OR] = 0.65, P = .002; 3-4d/wk: OR = 0.69, P = .004; ≥5 d/wk: OR = 0.57, P < .001). However, resistance training showed no association with the risk of CLBP.In this cross-sectional study, walking was associated with a lower risk of CLBP. In particular, walking >5days per week had the maximum benefit in a lower risk of CLBP. Therefore, clinicians can consider recommending walking to patients with CLBP for optimal pain improvement.

Comparison of Minimally Invasive Lateral Lumbar Interbody Fusion, Minimally Invasive Lateral Lumbar Interbody Fusion, and Open Posterior Lumbar Interbody Fusion in the Treatment of Single-Level Spondylolisthesis of L4-L5.

OBJECTIVE: To compare the outcomes of minimally invasive lateral lumbar interbody fusion (LLIF) with minimally invasive transforaminal lumbar interbody fusion (TLIF) and conventional open posterior lumbar interbody fusion (PLIF) for treating single-level spondylolisthesis at L4-L5. METHODS: The patients underwent minimally invasive LLIF (n = 18), minimally invasive TLIF (n = 17), and conventional open PLIF (n = 20) for spondylolisthesis at L4-L5. Reduction of slippage, improvement in segmental lordosis, and restoration of foraminal height were measured. Perioperative parameters such as blood loss and operation time and clinical outcomes such as visual analog scale score and Oswestry Disability Index were compared. RESULTS: Compared with the open PLIF group, the minimally invasive LLIF group showed greater restoration of mean foraminal height, significantly smaller mean intraoperative estimated blood loss, and less mean hemoglobin reduction on the third day postoperatively. Compared with the minimally invasive TLIF group, the minimally invasive LLIF group showed greater restoration of mean segmental lordosis. The minimally invasive LLIF group showed a significantly shorter mean time to start walking after surgery compared with the conventional open PLIF and minimally invasive TLIF groups. However, compared with the minimally invasive TLIF group, the minimally invasive LLIF group showed a significantly longer mean operating time. Clinical outcomes were not statistically different among the 3 groups. CONCLUSIONS: In the treatment of spondylolisthesis of L4-L5, minimally invasive LLIF provided an effective surgical alternative to minimally invasive TLIF or conventional open PLIF, with the advantages of less blood loss, the faster start of postoperative walking, and comparable improvement in radiologic parameters.

Comparative Study of Radiological and Clinical Outcomes in Patients Undergoing Minimally Invasive Lateral Lumbar Interbody Fusion Using Demineralized Bone Matrix Alone or with Low-Dose Escherichia coli-Derived rhBMP-2.

OBJECTIVE: To compare the results of interbody fusion in patients undergoing minimally invasive lateral lumbar interbody fusion (LLIF) using demineralized bone matrix (DBM) alone versus DBM+recombinant human bone morphogenetic protein-2 (rhBMP2). METHODS: This retrospective case-controlled study was conducted in patients undergoing minimally invasive LLIF (n = 54) for lumbar interbody fusion; they were divided into 2 groups: DBM-only group and DMB+rhBMP2 group. The improvements of segmental and lumbar lordosis and restoration of disc height were measured, and the interbody fusion rates were determined using a modified Bridwell grading system. Clinical outcomes after surgery, such as visual analog scale scores of back pain and leg pain, and Oswestry disability index were compared. RESULTS: There were no significant differences in disc height, lumbar and segmental lordosis, or interbody fusion rate between the 2 groups. However, the proportion of Bridwell grade 1 as complete interbody bridging was higher in the DBM+rhBMP2 group than in the DBM-only group at both 6 and 12 months (P < 0.001). Clinical parameters showed equally significant improvement during follow-up in both groups, with no significant differences between the groups. CONCLUSION: In minimally invasive LLIF, adding Escherichia coli-derived rhBMP2 to DBM did not affect clinical outcomes or radiation parameters, but increased the speed of fusion and interbody bony bridging rate.

Association between Chronic Knee Pain and Psychological Stress in Those over 50 Years of Age: A Nationwide Cross-Sectional Study Based on the Sixth Korea National Health and Nutrition Examination Survey (KNHANES 2013-2015).

Chronic knee pain (CKP) can degrade the quality of life and cause dysfunction, resulting in the loss of independence. Psychological stress not only affects physical and mental health but is also a risk factor for CKP. In this cross-sectional study, we analyzed data from the sixth Korea National Health and Nutrition Examination Survey (2013-2015), and investigated the association between CKP and psychological stress of the Korean general population. The CKP status was determined based on survey responses of self-reported knee pain lasting for more than 30 days during the last 3 months. Psychological stress was classified as none, mild, moderate, or severe. The association between CKP and psychological stress was analyzed using multiple logistic regression analysis considering co-variables and demographic data. Logistic regression analysis adjusting for co-variables indicated that the risk of CKP increased with an increasing degree of stress, from mild (OR = 1.65, 95% CI 1.35-2.03, p < 0.001) to moderate (OR = 2.00, 95% CI 1.56-2.57, p < 0.001) and severe (OR = 3.02, 95% CI 2.08-4.37, p < 0.001). A significant association between the risk of CKP and psychological stress was identified. Therefore, when evaluating patients with CKP, it may be helpful for clinicians to check the degree of stress.