Assessment of Biomechanical Advantages in Combined Anterior-Posterior Cervical Spine Surgery by Radiological Outcomes: Pedicle Screws over Lateral Mass Screws.

BACKGROUND: The combined anterior-posterior approach has shown good clinical outcomes for multilevel cervical diseases. This work describes the biomechanical advantage of cervical-pedicle-screw fixation over lateral-mass-screw fixation in combined anterior-posterior cases. METHOD: Seventy-six patients who received combined cervical surgery from June 2013 to December 2020 were included. The patients were divided into two groups: the lateral-mass-screw group (LMS) and the pedicle-screw group (PPS). Radiological outcomes were assessed with lateral cervical spine X-rays for evaluating sagittal alignment, subsidence, and bone remodeling. RESULTS: At 1 year postoperatively, the numbers of patients whose C2-C7 cervical lordosis was less than 20 degrees decreased by more in the PPS group (p-value = 0.001). The amount of vertical-length change from immediately to 1 year postsurgery was less in the PPS group than in the LMS group (p-value = 0.030). The mean vertebral-body-width change was larger in the PPS group than in the LMS group during 3 months to 1 year postsurgery (p-value = 0.000). CONCLUSIONS: In combined anterior-posterior cervical surgery cases, maintenance of cervical lordosis and protection of the vertebral body from subsidence were better with the pedicle-screw fixation. More bone remodeling occurred when using the pedicle-screw fixation method.

Assessing the effects of National Health Insurance reimbursement policy revisions for anti-osteoporotic drugs in Korean women aged 50 or older.

INTRODUCTION: The Korean National Health Insurance revised its reimbursement criteria to expand coverage for anti-osteoporotic drug treatments in 2011 (expanding diagnostic criteria and the coverage period for anti-osteoporotic therapy) and 2015 (including osteoporotic fracture patients regardless of bone mineral density). We examined whether the two revisions contributed to an increase in the prescription rates of anti-osteoporotic drugs in Korea. METHODS: We used the Health Insurance Review and Assessment Service-National Patient Sample data from 2010 through 2016. A segmented regression analysis of interrupted time series was performed to assess changes in the monthly prescription rates of anti-osteoporotic drugs among women aged 50 or older, defined as the proportion of elderly women prescribed with anti-osteoporotic drugs. RESULTS: Both the levels (i.e., abrupt jump or drop) and the trends (i.e., slope) of the prescription rates of anti-osteoporotic drugs in the general population, osteoporotic patients, and osteoporotic fracture patients showed no significant changes after the first revision. However, there was a significant increase in the trends in the general population (ß = 0.0166, p = 0.0173) and in osteoporotic patients (ß = 0.1128, p = 0.0157) after the second revision. Women aged 65 to 79 years were the most significantly increased group in terms of the treatment proportion after the second revision because the trend was significant after the second revision in all three study populations (ß = 0.0300, 0.1212, 0.1392, respectively; p < 0.05). CONCLUSIONS: Although the two revisions expanded reimbursement coverage, only the second revision on reimbursing based on osteoporotic fracture regardless of bone mineral density was associated with increasing the proportion of post-menopausal women being treated with anti-osteoporotic drugs.

Assessment of patient-reported outcomes (PROs): treatment satisfaction, medication adherence, and quality of life (QoL) and the associated factors in postmenopausal osteoporosis (PMO) patients in Korea.

Patient-reported outcomes (PROs) provide practical guides for treatment; however, studies that have evaluated PROs of women in Korea with postmenopausal osteoporosis (PMO) are lacking. This cross-sectional, multi-center (29 nationwide hospitals) study, performed from March 2013 to July 2014, aimed to assess PROs related to treatment satisfaction, medication adherence, and quality of life (QoL) in Korean PMO women using osteoporosis medication for prevention/treatment. Patient demographics, clinical characteristics, treatment patterns, PROs, and experience using medication were collected. The 14-item Treatment Satisfaction Questionnaire for Medication (TSQM) (score-range, 0-100; domains: effectiveness, side effects, convenience, global satisfaction), Osteoporosis-Specific Morisky Medication Adherence Scale (OS-MMAS) (score-range, 0-8), and EuroQol-5 dimensions questionnaire (index score range, - 0.22 to 1.0; EuroQol visual analog scale score range, 0-100) were used. To investigate factors associated with PROs, linear (treatment satisfaction/QoL) or logistic (medication adherence) regression analyses were conducted. A total of 1804 patients (age, 62 years) were investigated; 60.1% used bisphosphonate, with the majority (67.2%) using weekly medication, 27.8% used daily hormone replacement therapy, and 12.1% used daily selective estrogen receptor modulator. Several patients reported gastrointestinal (GI) events (31.6%) and dental visits due to problems (24.1%) while using medication. Factors associated with the highest OS-MMAS domain scores were convenience and global satisfaction. GI events were associated with non-adherence. TSQM scores for effectiveness, side effects, and GI risk factors were significantly associated with QoL. Our study elaborately assessed the factors associated with PROs of Korean PMO women. Based on our findings, appropriate treatment-related adjustments such as frequency/choice of medications and GI risk management may improve PROs.

Cost-effectiveness of Pharmaceutical Interventions to Prevent Osteoporotic Fractures in Postmenopausal Women with Osteopenia.

BACKGROUND: To assess the cost-effectiveness of drug therapy to prevent osteoporotic fractures in postmenopausal women with osteopenia in Korea. METHODS: A Markov cohort simulation was conducted for lifetime with a hypothetical cohort of postmenopausal women with osteopenia and without prior fractures. They were assumed to receive calcium/vitamin D supplements only or drug therapy (i.e., raloxifene or risedronate) along with calcium/vitamin D for 5 years. The Markov model includes fracture-specific and non-fracture specific health states (i.e. breast cancer and venous thromboembolism), and all-cause death. Published literature was used to determine the model parameters. Local data were used to estimate the baseline incidence rates of fracture in those with osteopenia and the costs associated with each health state. RESULTS: From a societal perspective, the estimated incremental cost-effectiveness ratios (ICERs) for the base cases that had T-scores between -2.0 and -2.4 and began drug therapy at the age of 55, 60, or 65 years were $16,472, $6,741, and -$13,982 per quality-adjusted life year (QALY) gained, respectively. Sensitivity analyses for medication compliance, risk of death following vertebral fracture, and relaxing definition of osteopenia resulted in ICERs reached to $24,227 per QALY gained. CONCLUSIONS: ICERs for the base case and sensitivity analyses remained within the World Health Organization's willingness-to-pay threshold, which is less than per-capita gross domestic product in Korea (about $25,700). Thus, we conclude that drug therapy for osteopenia would be a cost-effective intervention, and we recommend that the Korean National Health Insurance expand its coverage to include drug therapy for osteopenia.

Development and Validation of Osteoporosis Risk-Assessment Model for Korean Men.

PURPOSE: The aim of the present study was to develop an osteoporosis risk-assessment model to identify high-risk individuals among Korean men. MATERIALS AND METHODS: The study used data from 1340 and 1110 men ≥50 years who participated in the 2009 and 2010 Korean National Health and Nutrition Examination Survey, respectively, for development and validation of an osteoporosis risk-assessment model. Osteoporosis was defined as T score ≤-2.5 at either the femoral neck or lumbar spine. Performance of the candidate models and the Osteoporosis Self-assessment Tool for Asian (OSTA) was compared with sensitivity, specificity, and area under the receiver operating characteristics curve (AUC). A net reclassification improvement was further calculated to compare the developed Korean Osteoporosis Risk-Assessment Model for Men (KORAM-M) with OSTA. RESULTS: In the development dataset, the prevalence of osteoporosis was 8.1%. KORAM-M, consisting of age and body weight, had a sensitivity of 90.8%, a specificity of 42.4%, and an AUC of 0.666 with a cut-off score of -9. In the validation dataset, similar results were shown: sensitivity 87.9%, specificity 39.7%, and AUC 0.638. Additionally, risk categorization with KORAM-M showed improved reclassification over that of OSTA up to 22.8%. CONCLUSION: KORAM-M can be simply used as a pre-screening tool to identify candidates for dual energy X-ray absorptiometry tests.

Development and validation of osteoporosis risk-assessment model for Korean postmenopausal women.

Currently, dual-energy X-ray absorptiometry (DXA) is the gold standard for detecting osteoporosis, but is not recommended for general population screening. Therefore, this study aims to develop an osteoporosis risk-assessment model to identify high-risk individuals among Korean postmenopausal women. Data from 1,209 and 1,046 postmenopausal women who participated in the 2009 and 2010 Korean National Health and Nutrition Examination Survey, respectively, were used for development and validation of an osteoporosis risk-assessment model. Osteoporosis was defined as T score less than or equal to -2.5 at either the femoral neck or lumbar spine. Performance of the candidate models and the Osteoporosis Self assessment Tool for Asians (OSTA) were compared with respect to sensitivity, specificity, and area under the receiver operating characteristics curve (AUC). To compare the developed Korean Osteoporosis Risk-Assessment Model (KORAM) with OSTA, a net reclassification improvement was further calculated. In the development dataset, the prevalence of osteoporosis was 33.9 %. KORAM, consisting of age, weight, and hormone therapy, had a sensitivity of 91.2 %, a specificity of 50.6 %, and an AUC of 0.709 with a specific cut-off score of -9. Comparable results were shown in the validation dataset: sensitivity 84.8 %, specificity 51.6 %, and AUC 0.682. Additionally, risk categorization with KORAM showed improved reclassification over that of OSTA from 7.4 to 41.7 %. KORAM can be easily used as a pre-screening tool to identify candidates for DXA tests. Further studies investigating cost-effectiveness and replicability in other datasets are required to establish the clinical utility of KORAM.

The quantitative assessment of risk factors to overstress at adjacent segments after lumbar fusion: removal of posterior ligaments and pedicle screws.

STUDY DESIGN: Finite element method. OBJECTIVE: To investigate the changes in the disc stress and range of motion (ROM) at adjacent segments after lumbar fusion based on whether or not pedicle screws are removed and whether or not the continuity of the proximal posterior ligament complex (PLC) is preserved. SUMMARY OF BACKGROUND DATA: The ablation of proximal PLC continuity and the presence of pedicle screws have been reported to affect the biomechanics at adjacent segments after lumbar fusion. However, there have been few studies regarding the quantitative assessment of their contribution to overstress at adjacent segments after lumbar fusion. METHODS: In the validated intact lumbar finite element model (L2-L5), four types of L3-L4 fusion models were simulated. These models included the preservation of the PLC continuity with pedicle screws (Pp WiP), the preservation of PLC continuity without pedicle screws (Pp WoP), the sacrifice of PLC with pedicle screws (Sp WiP), and the sacrifice of PLC without pedicle screws (Sp WoP). In each scenario, the ROM, maximal von Mises stress of discs, and the facet joint contract force at adjacent segments were analyzed. RESULTS.: Among the four models, the Sp WiP yielded the greatest increase in the ROM and the maximal von Mises stress of the disc at adjacent segments under four moments. Following the SP WiP, the order of increase of the ROM and the disc stress was Pp WiP, Sp WoP, and Pp WoP. Furthermore, the increase of ROM and disc stress at the proximal adjacent segment was more than at the distal adjacent segment under all four moments in each model. The facet joint contact was also most increased in the Sp WiP under extension and torsion moment. CONCLUSION: The current study suggests that the preservation of the PLC continuity or the removal of pedicle screws after complete fusion could decrease the stress at adjacent segments, and their combination could act synergistically.

The risk assessment of a fall in patients with lumbar spinal stenosis.

STUDY DESIGN: A prospective case control study. OBJECTIVES: To investigate the risk of a fall by using functional mobility tests in patients with lumbar spinal stenosis (LSS) via a comparison with patients with knee osteoarthritis (KOA). SUMMARY OF BACKGROUND DATA: LSS is a degenerative arthritic disease in the spine that results in decreasing function, impaired balance, and gait deficit, with increased levels of leg and back pain. This physical impairment may result in an increased risk of fall later in the disease process, as shown in KOA. However, there has been no study regarding the association between the risk of a fall and LSS. METHODS: The study was an age- and weight-matched case control study consisting of two groups: one group consisting of 40 patients with LSS who were scheduled to undergo spine surgery (LSS group) and the other group consisting of 40 patients with advanced osteoarthritis in both knees, scheduled to undergo TKA on both knees (KOA group). For both groups, four functional mobility tests, such as a Six-Meter-Walk Test (SMT), Sit-to-Stand test (STS), Alternative-Step Test (AST), and Timed Up and Go Test (TUGT), were performed. RESULTS: There was no difference in demographic data between both groups except for body mass index. For the SMT and STS, the patients in the LSS group spent significantly more time performing these tests than the patients in the KOA. For the AST, however, patients in the KOA group presented a statistically worse performance in functional mobility, compared with the LSS group. The mean TUGT time was not statistically different between the two groups. CONCLUSIONS: The current study highlights that patients with symptomatic LSS have a risk of a fall comparable with the patients who had degenerative KOA based on the results of functional mobility tests (SMT, STS, AST, and TUGT).

Incidence and mortality of hip fracture among the elderly population in South Korea: a population-based study using the national health insurance claims data.

BACKGROUND: The lack of epidemiologic information on osteoporotic hip fractures hampers the development of preventive or curative measures against osteoporosis in South Korea. We conducted a population-based study to estimate the annual incidence of hip fractures. Also, we examined factors associated with post-fracture mortality among Korean elderly to evaluate the impact of osteoporosis on our society and to identify high-risk populations. METHODS: The Korean National Health Insurance (NHI) claims database was used to identify the incidence of hip fractures, defined as patients having a claim record with a diagnosis of hip fracture and a hip fracture-related operation during 2003. The 6-month period prior to 2003 was set as a 'window period,' such that patients were defined as incident cases only if their first record of fracture was observed after the window period. Cox's proportional hazards model was used to investigate the relationship between survival time and baseline patient and provider characteristics available from the NHI data. RESULTS: The age-standardized annual incidence rate of hip fractures requiring operation over 50 years of age was 146.38 per 100,000 women and 61.72 per 100,000 men, yielding a female to male ratio of 2.37. The 1-year mortality was 16.55%, which is 2.85 times higher than the mortality rate for the general population (5.8%) in this age group. The risk of post-fracture mortality at one year is significantly higher for males and for persons having lower socioeconomic status, living in places other than the capital city, not taking anti-osteoporosis pharmacologic therapy following fracture, or receiving fracture-associated operations from more advanced hospitals such as general or tertiary hospitals. CONCLUSION: This national epidemiological study will help raise awareness of osteoporotic hip fractures among the elderly population and hopefully motivate public health policy makers to develop effective national prevention strategies against osteoporosis to prevent hip fractures.

Estimating medical expenditure associated with osteoporotic hip fracture in elderly Korean women based on the National Health Insurance Claims Database 2002-2004.

OBJECTIVES: To estimate the medical expenditure associated with osteoporotic hip fracture in elderly Korean women from insurer's perspective. METHODS: All claim records of women aged > or =50 years and diagnosed with hip fracture from 2002 to 2004 were obtained from the Korean National Health Insurance. The first 6 months were considered a "window period" during which patients with fractures were defined as incident cases if their initial records of visit or admission were observed after June 30, 2002. We included only those with claim records showing diagnosis of osteoporosis or prescription for antiosteoporosis drugs. For each patient, we calculated the cumulative claims amount related to the initial and follow-up treatment for 2 years after fracture. RESULTS: A total of 22,247 patients were identified during 2.5 years. During the first year of fracture, an average of 3.28 visits and 0.97 admissions were recorded; during the second year, 0.35 visits and 0.02 admissions were recorded. The 2-year cost per patient was KRW3,175,467, 97.4% of which was incurred during first year. CONCLUSION: Exploring the economic burden of osteoporotic hip fracture in the elderly women is expected to motivate policymakers and clinicians to adopt effective treatment options for the disease prevention and expenditure control.

[Estimating the economic burden of osteoporotic vertebral fracture among elderly Korean women].

OBJECTIVES: To estimate the economic burden of osteoporotic vertebral fracture (VF) from a societal perspective. METHODS: From 2002 to 2004, we identified all National Health Insurance claims records for women >or= 50 years old with a diagnosis of VF. The first 6-months was defined as a "clearance period," Ysuch that patients were considered as incident cases if their first claim of fracture was recorded after June 30, 2002. We only included patients with >or= one claim of a diagnosis of, or prescription for, osteoporosis over 3 years. For each patient, we cumulated the claims amount for the first visit and for the follow-up treatments for 1 year. The hospital charge data from 4 hospitals were investigated to measure the proportion of the non-covered services. Face-to-face interviews were conducted with 106 patients from the 4 study sites to measure the out-of-pocket spending outside of hospitals. RESULTS: During 2.5 years, 131,453 VF patients were identified. The patients had an average of 3.38 visits, 0.40 admissions and 6.36 inpatient days. The per capita cost was 1,909,690 Won: 71.5% for direct medical costs, 20.6% for direct non-medical costs and 7.9% for indirect costs. The per capita cost increased with increasing age: 1,848,078 Won for those aged 50-64, 2,084,846 Won for 65-74, 2,129,530 Won for 75-84 and 2,121,492 Won for those above 84. CONCLUSIONS: Exploring the economic burden of osteoporotic VF is expected to motivate to adopt effective treatment options for osteoporosis in order to prevent the incidence of fracture and the consequent costs.