Trends in degenerative lumbar spinal surgery during the early COVID-19 pandemic in Republic of Korea: A national study utilizing the national health insurance database.

During the first year of the COVID-19 pandemic, the Republic of Korea (ROK) experienced three epidemic waves in February, August, and November 2020. These waves, combined with the overarching pandemic, significantly influenced trends in spinal surgery. This study aimed to investigate the trends in degenerative lumbar spinal surgery in ROK during the early COVID-19 pandemic, especially in relation to specific epidemic waves. Using the National Health Information Database in ROK, we identified all patients who underwent surgery for degenerative lumbar spinal diseases between January 1, 2019 and December 31, 2020. A joinpoint regression was used to assess temporal trends in spinal surgeries over the first year of the COVID-19 pandemic. The number of surgeries decreased following the first and second epidemic waves (p<0.01 and p = 0.34, respectively), but these were offset by compensatory increases later on (p<0.01 and p = 0.05, respectively). However, the third epidemic wave did not lead to a decrease in surgical volume, and the total number of surgeries remained comparable to the period before the pandemic. When compared to the pre-COVID-19 period, average LOH was reduced by 1 day during the COVID-19 period (p<0.01), while mean hospital costs increased significantly from 3,511 to 4,061 USD (p<0.01). Additionally, the transfer rate and the 30-day readmission rate significantly decreased (both p<0.01), while the reoperation rate remained stable (p = 0.36). Despite the impact of epidemic waves on monthly surgery numbers, a subsequent compensatory increase was observed, indicating that surgical care has adapted to the challenges of the pandemic. This adaptability, along with the stable total number of operations, highlights the potential for healthcare systems to continue elective spine surgery during public health crises with strategic resource allocation and patient triage. Policies should ensure that surgeries for degenerative spinal diseases, particularly those not requiring urgent care but crucial for patient quality of life, are not unnecessarily halted.

Comparison of the Clinical Efficacy of Anabolic Agents and Bisphosphonates in the Patients With Osteoporotic Vertebral Fracture: Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: We investigated the clinical efficacy of anabolic agents compared with bisphosphonates (BPs) for the incidence of new osteoporotic vertebral fracture (OVF) and fracture healing of OVF in the patients with OVF via meta-analyses of randomized controlled trials (RCTs). METHODS: Electronic databases, including PubMed, Embase, and Cochrane Library were searched for published RCTs till December 2022. The RCTs that recruited participants with osteoporosis at high-/very high-risk of fracture (a history of osteoporotic vertebral or hip fracture) or fresh OVF were included in this study. We assessed the risk of bias on every included RCTs, estimated relative risk (RR) for the incidence of new OVF and fracture healing of OVF, and overall certainty of evidence. Meta-analyses were performed by Cochrane review manager (RevMan) ver. 5.3. Cochrane risk of bias 2.0 and GRADEpro/GDT were applied for evaluating methodological quality and overall certainty of evidence, respectively. RESULTS: Five hundred eighteen studies were screened, and finally 6 eligible RCTs were included in the analysis. In the patients with prevalent OVF, anabolic agents significantly reduced the incidence of new OVF (teriparatide and romosozumab vs. alendronate and risedronate [RR, 0.57; 95% confidence interval, 0.45-0.71; p < 0.00001; high-certainty of evidence]; teriparatide vs. risedronate [RR, 0.50; 95% confidence interval, 0.37-0.68; p < 0.0001; high-certainty of evidence]). However, there was no evidence of teriparatide compared to alendronate in fracture healing of OVF (RR, 1.23; 95% confidence interval, 0.95-1.60; p = 0.12; low-certainty of evidence). CONCLUSION: In the patients with prevalent OVF, anabolic agents showed a significant superiority for preventing new OVF than BPs, with no significant evidence for promoting fracture healing of OVF. However, considering small number of RCTs in this study, additional studies with large-scale data are required to obtain more robust evidences.

Ecotoxicity assessment of additives in commercial biodegradable plastic products: Implications for sustainability and environmental risk.

Biodegradable plastics have gained popularity as environmentally friendly alternatives to conventional petroleum-based plastics, which face recycling and degradation challenges. Although the biodegradability of these plastics has been established, research on their ecotoxicity remains limited. Biodegradable plastics may still contain conventional additives, including toxic and non-degradable substances, to maintain their functionality during production and processing. Despite degrading the polymer matrix, these additives can persist in the environment and potentially harm ecosystems and humans. Therefore, this study aimed to assess the potential ecotoxicity of biodegradable plastics by analyzing the phthalate esters (PAEs) leaching out from biodegradable plastics through soil leachate. Sixteen commercial biodegradable plastic products were qualitatively and quantitatively analyzed using gas chromatography-mass spectrometry to determine the types and amounts of PAE used in the products and evaluate their ecotoxicity. Among the various PAEs analyzed, non-regulated dioctyl isophthalate (DOIP) was the most frequently detected (ranging from 40 to 212 µg g-1). Although the DOIP is considered one of PAE alternatives, the detected amount of it revealed evident ecotoxicity, especially in the aquatic environment. Other additives, including antioxidants, lubricants, surfactants, slip agents, and adhesives, were also qualitatively detected in commercial products. This is the first study to quantify the amounts of PAEs leached from biodegradable plastics through water mimicking PAE leaching out from biodegradable plastics to soil leachate when landfilled and evaluate their potential ecotoxicity. Despite their potential toxicity, commercial biodegradable plastics are currently marketed and promoted as environmentally friendly materials, which could lead to indiscriminate public consumption. Therefore, in addition to improving biodegradable plastics, developing eco-friendly additives is significant. Future studies should investigate the leaching kinetics in soil leachate over time and toxicity of biodegradable plastics after landfill disposal.

Next-generation all-organic composites: A sustainable successor to organic-inorganic hybrid materials.

This Review presents an overview of all-organic nanocomposites, a sustainable alternative to organic-inorganic hybrids. All-organic nanocomposites contain nanocellulose, nanochitin, and aramid nanofibers as highly rigid reinforcing fillers. They offer superior mechanical properties and lightweight characteristics suitable for diverse applications. The Review discusses various methods for preparing the organic nanofillers, including top-down and bottom-up approaches. It highlights in situ polymerization as the preferred method for incorporating these nanomaterials into polymer matrices to achieve homogeneous filler dispersion, a crucial factor for realizing desired performance. Furthermore, the Review explores several applications of all-organic nanocomposites in diverse fields including food packaging, performance-advantaged plastics, and electronic materials. Future research directions-developing sustainable production methods, expanding biomedical applications, and enhancing resistance against heat, chemicals, and radiation of all-organic nanocomposites to permit their use in extreme environments-are explored. This Review offers insights into the potential of all-organic nanocomposites to drive sustainable growth while meeting the demand for high-performance materials across various industries.

Structural evaluation of Poly(lactic acid) degradation at standardized composting temperature of 58 degrees.

The accumulation of petroleum-based plastics on our planet is causing serious environmental pollution. Biodegradable plastics, promoted as eco-friendly solutions, hold the potential to address this issue. However, their impact on the environment and the mechanisms of their natural degradation remain inadequately understood. Furthermore, the specific conditions set forth in international standards for evaluating the biodegradability of biodegradable plastics have led to misconceptions about their real-world behavior. To properly elucidate the relationship between their degradability and structure, this study mimics the thermal effect on poly(lactic acid) (PLA) under standardized composting temperature. The higher the crystallinity of PLA, the lower the degradation rate, which suggests that crystallinity is a key factor in determining degradation. The composting temperature of 58 °C induces crystallization by having a structural effect on the polymer, which in turn reduces the degradation rate of PLA. Therefore, control over temperature and crystallization during the processing and degradation of PLA is crucial, as it not only determines the biodegradability but also enhances the utility.

Screening patients requiring secondary lumbar surgery for degenerative lumbar spine diseases: a nationwide sample cohort study.

This study aims to identify healthcare costs indicators predicting secondary surgery for degenerative lumbar spine disease (DLSD), which significantly impacts healthcare budgets. Analyzing data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database of Republic of Korea (ROK), the study included 3881 patients who had surgery for lumbar disc herniation (LDH), lumbar spinal stenosis without spondylolisthesis (LSS without SPL), lumbar spinal stenosis with spondylolisthesis (LSS with SPL), and spondylolysis (SP) from 2006 to 2008. Patients were categorized into two groups: those undergoing secondary surgery (S-group) and those not (NS-group). Surgical and interim costs were compared, with S-group having higher secondary surgery costs ($1829.59 vs $1618.40 in NS-group, P = 0.002) and higher interim costs ($30.03; 1.86% of initial surgery costs vs $16.09; 0.99% of initial surgery costs in NS-group, P < 0.0001). The same trend was observed in LDH, LSS without SPL, and LSS with SPL (P < 0.0001). Monitoring interim costs trends post-initial surgery can effectively identify patients requiring secondary surgery.

Preparation of a nanocellulose/nanochitin coating on a poly(lactic acid) film for improved hydrolysis resistance.

Growing concerns regarding plastic waste have prompted various attempts to replace plastic packaging films with biodegradable alternatives such as poly(lactic acid) (PLA). However, their low hydrolysis resistance owing to the presence of aliphatic polyesters limits the shelf life of biodegradable polymers. Hydrolysis leads to the deterioration of mechanical performance, which is a key disadvantage of biodegradable plastics. In this study, a layer-by-layer (LBL) assembly method was used for the dip-coating of biorenewable, biodegradable nanocellulose/nanochitin on the PLA surface. Additional crosslinking and compression of the coated nanofibers, each containing carboxylic acid and amine groups, respectively, were induced through electromagnetic microwave irradiation to protect the PLA film by improving hydrolysis resistance. The coatings were examined by morphological observations and water contact angle measurements. The LBL coatings of differently charged nanofibers of 10.6 µm were reduced to 40 % after microwave treatment, and the thickness does not vary after the hydrolysis experiment. Microwave irradiation increased the water contact angle owing to amide linkage formation, thereby preventing the peeling off of coating layers. Improved hydrolysis resistance inhibited the reduction in molecular weight and tensile strength. These findings could be used to develop sustainable and biodegradable plastic packaging films with a prolonged shelf life.

Prior tuberosity screw fixation of the osteotomized tubercle can lead to favorable outcomes in retro-tubercular bi-planar opening wedge high tibial osteotomy.

BACKGROUND: Exact information regarding fixing the tuberosity screw during retro-tubercular opening-wedge high tibial osteotomy (RT-OWHTO) is still lacking. The purpose of this study was to determine whether prior tuberosity screw fixation before plate fixation of main osteotomy fragment can prevent complications associated with tuberosity screw. METHODS: From 2019 to 2021, patients who underwent RT-OWHTO were divided into two groups (group I, prior tuberosity screw fixation; group II, later tuberosity screw fixation). A total of 49 and 44 knees were included in groups I and II, respectively. Plain radiographs and computed tomography (CT) were used to analyze the parameters of tuberosity screw fixation, neurovascular (NV) safety and osteotomy configurations. Clinical outcomes and post-operative complications were assessed. RESULTS: The delta (Δ) of the deformation angle of the tuberosity (P = 0.002), delta (Δ) of the posterior tibial slope (PTS) (P < 0.001), extruded screw length (P < 0.001), and retro-tuberosity tip distance (P < 0.001) of group I were significantly smaller than those of group II. All tuberosity screws were fixed medially to the NV structures. Post-operative tuberosity fracture occurred in one knee (2%) in group I and in 10 knees (23%) in group II (P = 0.003). CONCLUSIONS: RT-OWHTO with prior tuberosity screw fixation can minimize the risk of tuberosity fracture and an increase in the PTS. It can also prevent NV injuries by reducing extruded tuberosity screw length and fixing it medially from the NV structures.

Circular waste management: Superworms as a sustainable solution for biodegradable plastic degradation and resource recovery.

Bioplastics offer a promising solution to plastic pollution, however, their production frequently relies on edible biomass, and their degradation rates remain inadequate. This study investigates the potential of superworms (Zophobas atratus larvae) for polybutylene succinate (PBS) waste management, aiming to achieve both resource recovery and biodegradation. Superworms exclusively fed on PBS for a month exhibited the same survival rate as those on a standard bran diet. PBS digestion yielded a 5.13% weight gain and a 23.23% increase in protein composition in superworms. Additionally, carbon isotope analyses substantiated the conversion of PBS into superworm components. Gut microbes capable of PBS biodegradation became progressively prominent, further augmenting the degradation rate of PBS under composting conditions (ISO 14855-1). Gut-free superworms fed with PBS exhibited antioxidant activities comparable to those of blueberries, renowned for their high antioxidant activity. Based on these findings, this study introduces a sustainable circular solution encompassing recycling PBS waste to generate insect biomass, employing insect gut and frass for PBS degradation and fertilizer, and harnessing insect residue as a food source. In essence, the significance of this research extends to socio-economic and environmental spheres, impacting waste management, resource efficiency, circular economy promotion, environmental preservation, industrial advancement, and global sustainability objectives. The study's outcomes possess the potential to reshape society's approach to plastic waste, facilitating a shift toward more sustainable paradigms.

Probabilistic graphical modelling using Bayesian networks for predicting clinical outcome after posterior decompression in patients with degenerative cervical myelopathy.

BACKGROUND: Probabilistic graphical modelling (PGM) can be used to predict risk at the individual patient level and show multiple outcomes and exposures in a single model. OBJECTIVE: To develop PGM for the prediction of clinical outcome in patients with degenerative cervical myelopathy (DCM) after posterior decompression and to use PGM to identify causal predictors of the outcome. METHODS: We included data from 59 patients who had undergone cervical posterior decompression for DCM. The candidate predictive parameters were age, sex, body mass index, trauma history, symptom duration, preoperative and last Japanese Orthopaedic Association (JOA) scores, gait impairment, claudication, bladder dysfunction, Nurick grade, American Spinal Injury Association (ASIA) grade, smoking, diabetes mellitus, cardiopulmonary disorders, hypertension, stroke, Parkinson's disease, dementia, psychiatric disorders, arthritis, ossification of the posterior longitudinal ligament, cord signal change, postoperative kyphosis and the cord compression ratio. RESULTS: In regression analyses, preoperative JOA (PreJOA) score, presence of a psychiatric disorder, and ASIA grade were identified as significant factors associated with the last JOS score. Dementia, sex, PreJOA score and gait impairment were causal factors in the PGM. Sex, dementia and PreJOA score were direct causal factors related to the last follow-up JOA (LastJOA) score. Being female, having dementia, and having a low PreJOA score were significantly related to having a low LastJOA score. CONCLUSIONS: The causal predictors of surgical outcome for DCM were sex, dementia and PreJOA score. Therefore, PGM may be a useful personalized medicine tool for predicting the outcome of patients with DCM.

Sex, dementia and preoperative neurological status are causal factors contributing to the postoperative outcome of patients with degenerative cervical myelopathy.The Bayesian network (BN) structure may be useful for predicting the probability for clinical outcomes for each patient who undergoes posterior decompressive surgery.The BN structure may provide a useful model in the current era of personalized medicine.

Clinical relevance of roll-back replacement of ultra congruent total knee arthroplasty: comparison of mid-term outcomes with posterior stabilizing design.

INTRODUCTION: The outcomes of total knee arthroplasty (TKA) remain controversial, and we do not know which factors are important for successful outcomes. This study aimed to compare the mid-term outcomes of different conceptual designs by evaluating the radiological and clinical outcomes. MATERIALS AND METHODS: A total of 478 total knee arthroplasties (TKAs) were enrolled and allocated into groups I [posterior stabilizing (PS) with anterior referencing (AR)], II [PS with posterior referencing (PR), and III [ultra-congruent (UC) TKA)]. Preoperative findings, last follow-up clinical outcomes, and final follow-up radiological and indirect assessments of the femoral rollback were compared between the groups. RESULTS: The mean follow-up period was 72.6 ± 12.9 months. The tourniquet was used samely applied to every group. Flexion contracture was significantly larger in group III than in groups I and II (3.3 ± 2.7, p < 0.001), and further flexion was significantly smaller in group III (130.0° ± 2.7°, p < 0.001). Among the radiological parameters, posterior osteophyte formation was the most common in group III (67.8%). The rollback distance was significantly smaller in group III than in groups I and II (p < 0.001). The active deep flexion angle was affected by the posterior condylar offset (PCO) ratio, and the contact point changed the distance (p < 0.05). CONCLUSION: PS TKAs showed better ROMs than UC TKAs; however, no differences were noted in the clinical outcome scales. The flexion angle was affected by the PCOR and rollback at both PS and UC TKAs. However, rollback negatively affected the flexion angle during UC TKAs. An inappropriate femoral rollback was identified, and femoral osteophyte formation was determined to be the most prominent in UC TKAs. Level of evidence Level III comparative study.

Cost-utility analysis of endoscopic lumbar discectomy following a uniform clinical pathway in the Korean national health insurance system.

INTRODUCTION: Full-endoscopic lumbar discectomy (FELD) is a type of minimally invasive spinal surgery for lumbar disc herniation (LDH). Sufficient evidence exists to recommend FELD as an alternative to standard open microdiscectomy, and some patients prefer FELD due to its minimally invasive nature. However, in the Republic of Korea, the National Health Insurance System (NHIS) controls the reimbursement and use of supplies for FELD, but FELD is not currently reimbursed by the NHIS. Nonetheless, FELD has been performed upon patients' request, but providing FELD for patients' sake is inherently an unstable arrangement in the absence of a practical reimbursement system. The purpose of this study was to conduct a cost-utility analysis of FELD to suggest appropriate reimbursements. METHOD: This study was a subgroup analysis of prospectively collected data including 28 patients who underwent FELD. All patients were NHIS beneficiaries and followed a uniform clinical pathway. Quality-adjusted life years (QALYs) were assessed with a utility score using the EuroQol 5-Dimension (EQ-5D) instrument. The costs included direct medical costs incurred at the hospital for 2 years and the price of the electrode ($700), although it was not reimbursed. The costs and QALYs gained were used to calculate the cost per QALY gained. RESULT: Patients' mean age was 43 years and one-third (32%) were women. L4-5 was the most common surgical level (20/28, 71%) and extrusion was the most common type of LDH (14, 50%). Half of the patients (15, 54%) had jobs with an intermediate level of activity. The preoperative EQ-5D utility score was 0.48±0.19. Pain, disability, and the utility score significantly improved starting 1 month postoperatively. The average EQ-5D utility score during 2 years after FELD was estimated as 0.81 (95% CI: 0.78-0.85). For 2 years, the mean direct costs were $3,459 and the cost per QALY gained was $5,241. CONCLUSION: The cost-utility analysis showed a quite reasonable cost per QALY gained for FELD. A comprehensive range of surgical options should be provided to patients, for which a practical reimbursement system is a prerequisite.

Nationwide sample data analysis of additional surgery rate after anterior or posterior cervical spinal surgery.

Surgical outcomes of degenerative cervical spinal disease are dependent on the selection of surgical techniques. Although a standardized decision cannot be made in an actual clinical setting, continued education is provided to standardize the medical practice among surgeons. Therefore, it is necessary to supervise and regularly update overall surgical outcomes. This study aimed to compare the rate of additional surgery between anterior and posterior surgeries for degenerative cervical spinal disease using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) nationwide patient database. The NHIS-NSC is a population-based cohort with about a million participants. This retrospective cohort study included 741 adult patients (> 18 years) who underwent their first cervical spinal surgery for degenerative cervical spinal disease. The median follow-up period was 7.3 years. An event was defined as the registration of any type of cervical spinal surgery during the follow-up period. Event-free survival analysis was used for outcome analysis, and the following factors were used as covariates for adjustment: location of disease, sex, age, type of insurance, disability, type of hospital, Charles comorbidity Index, and osteoporosis. Anterior cervical surgery was selected for 75.0% of the patients, and posterior cervical surgery for the remaining 25.0%. Cervical radiculopathy due to foraminal stenosis, hard disc, or soft disc was the primary diagnosis in 78.0% of the patients, and central spinal stenosis was the primary diagnosis in 22.0% of them. Additional surgery was performed for 5.0% of the patients after anterior cervical surgery and 6.5% of the patients after posterior cervical surgery (adjusted subhazard ratio, 0.83; 95% confidence interval, 0.40-1.74). The rates of additional surgery were not different between anterior and posterior cervical surgeries. The results would be helpful in evaluating current practice as a whole and adjusting the health insurance policy.

Method to analyze phthalate esters from soft toys dissolving into water mimicking infant playing.

Along with bisphenol-A (BPA), conventional phthalate esters (PAEs) have been reported as environmental hormones, despite their functional usefulness as plasticizers. Nevertheless, they are frequently found in various products, including children's utensils and toys made of poly (vinyl chloride). This is tremendously important because PAEs are harmful to infants. In addition, gel/slime-type toys made of poly (vinyl alcohol) are currently popular for developing infant' tactile senses. In this study, we developed a method to qualitatively and quantitatively detect PAEs in gel/slime-type toys mimicking, infants playing with them in a bathtub. As a result, 1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH), one of the PAE alternatives, transferred into the water from the toys and was detected most commonly (108-719 µg g-1; 0.01-0.07 wt%) among PAEs. The detected DINCH levels were below the universally accepted levels for PAEs (0.1 wt%). However, the amount of DINCH detected could still be toxic, in accordance with toxicity tests using water fleas. Furthermore, unpleasant odors were emitted when the toys containing toxic volatile organic compounds were unpacked. This is the first study to develop a method to analyze PAE in gel/slime-type toys and determine that alternatives to conventional PAEs cannot be unconditionally regarded as safe chemicals. Therefore, the revised standards for regulating PAEs and their alternatives must be reconsidered.

Fracture Liaison Service in Korea: 2022 Position Statement of the Korean Society for Bone and Mineral Research.

Osteoporosis and osteoporotic fractures cause socioeconomic concerns, and medical system and policies appear insufficient to prepare for these issues in Korea, where the older adult population is rapidly increasing. Many countries around the world are already responding to osteoporosis and osteoporotic fractures by adopting fracture liaison service (FLS), and such an attempt has only begun in Korea. In this article, we introduce the operation methods for institutions implementing FLS and characteristics of services, and activities of the FLS Committee for FLS implementation in the Korean Society for Bone and Mineral Research. In addition, we hope that the current position statement will contribute to the implementation of FLS in Korea and impel policy changes to enable a multidisciplinary and integrated FLS operated under the medical system.

Effectiveness of arthroscopic excision based on the distribution of the tenosynovial giant cell tumor around knee joint.

BACKGROUND: The mainstay treatment for tenosynovial giant cell tumor (TGCT) is open excision. However, open excision is associated with the risk of stiffness, infection, neurovascular injury, and prolonged hospital stay and rehabilitation. The purpose of this study was to evaluate the efficacy of arthroscopic excision of tenosynovial giant cell tumor (TGCT) of the knee joint, including the diffuse type of TGCT. METHODS: Patients who underwent arthroscopic excision of TGCT between April 2014 and November 2020 were retrospectively analyzed. TGCT lesions were divided into 12 distributions (nine intra- and three extra-articular lesions). The distribution of TGCT lesions, portals used, degree of excision, recurrence, and magnetic resonance imaging (MRI) scans were evaluated. The prevalence of intra-articular lesions in diffuse TGCT was also analyzed to validate the existence of a connection between intra- and extra-articular lesions. RESULTS: Twenty-nine patients were included in the study. Fifteen patients (52%) had localized TGCT, and 14 patients (48%) had diffuse TGCT. The recurrence rates for localized, and diffuse TGCT were 0%, and 7%, respectively. Intra-articular posteromedial (i-PM), intra-articular posterolateral (i-PL), and extra-articular posterolateral (e-PL) lesions were found in all patients with diffuse TGCT. The prevalence rates of i-PM and i-PL lesions among e-PL lesions were both 100% (p = 0.026 and p < 0.001, respectively). Diffuse TGCT lesions were managed with posterolateral capsulotomy and viewed from the trans-septal portal. CONCLUSIONS: Arthroscopic excision of TGCT was effective in both localized and diffuse TGCT. However, diffuse TGCT was associated with posterior and extra-articular lesions. Therefore, technical modification such as posterior, trans-septal portal, and capsulotomy were required. STUDY DESIGN: Retrospective case series; level Ⅳ.

Do Individualized Patient-Specific Situations Predict the Progression Rate and Fate of Knee Osteoarthritis? Prediction of Knee Osteoarthritis.

Factors affecting the progression rate and fate of osteoarthritis need to be analyzed when considering patient-specific situation. This study aimed to identify the rate of remarkable progression and fate of primary knee osteoarthritis based on patient-specific situations. Between May 2003 and May 2019, 83,280 patients with knee pain were recruited for this study from the clinical data warehouse. Finally, 2492 knees with pain that were followed up for more than one year were analyzed. For analyzing affecting factors, patient-specific information was categorized and classified as demographic, radiologic, social, comorbidity disorders, and surgical intervention data. The degree of contribution of factors to the progression rate and the fate of osteoarthritis was analyzed. Bone mineral density (BMD), Kellgren-Lawrence (K-L) grade, and physical occupational demands were major contributors to the progression rate of osteoarthritis. Hypertension, initial K-L grade, and physical occupational demands were major contributors to the outcome of osteoarthritis. The progression rate and fate of osteoarthritis were mostly affected by the initial K-L grade and physical occupational demands. Patients who underwent surgical intervention for less than five years had the highest proportion of initial K-L grade 2 (49.0%) and occupations with high physical demand (41.3%). In identifying several contributing factors, the initial K-L grade and physical occupational demands were the most important factors. BMD and hypertension were also major contributors to the progression and fate of osteoarthritis, and the degree of contribution was lower compared to the two major factors.

Cervical kinematic change after posterior full-endoscopic cervical foraminotomy for disc herniation or foraminal stenosis.

OBJECTIVE: Posterior full-endoscopic cervical foraminotomy (PECF) is one of minimally invasive surgical techniques for cervical radiculopathy. Because of minimal disruption of posterior cervical structures, such as facet joint, cervical kinematics was minimally changed. However, a larger resection of facet joint is required for cervical foraminal stenosis (FS) than disc herniation (DH). The objective was to compare the cervical kinematics between patients with FS and DH after PECF. METHODS: Consecutive 52 patients (DH, 34 vs. FS, 18) who underwent PECF for single-level radiculopathy were retrospectively reviewed. Clinical parameters (neck disability index, neck pain and arm pain), and segmental, cervical and global radiological parameters were compared at postoperative 3, 6, and 12 months, and yearly thereafter. A linear mixed-effect model was used to assess interactions between groups and time. Any occurrence of significant pain during follow-up was recorded during a mean follow-up period of 45.5 months (range 24-113 months). RESULTS: Clinical parameters improved after PECF, with no significant differences between groups. Recurrent pain occurred in 6 patients and surgery (PECF, anterior discectomy and fusion) was performed in 2 patients. Pain-free survival rate was 91% for DH and 83% for FS, with no significant difference between the groups (P = 0.29). Radiological changes were not different between groups (P > 0.05). Segmental neutral and extension curvature became more lordotic. Cervical curvature became more lordotic on neutral and extension X-rays, and the range of cervical motion increased. The mismatch between T1-slope and cervical curvature decreased. Disc height did not change, but the index level showed degeneration at postoperative 2 years. CONCLUSION: Clinical and radiological outcomes after PECF were not different between DH and FS patients and kinematics were significantly improved. These findings may be informative in a shared decision-making process.

Is there any benefit in the combined ligament reconstruction with osteotomy compared to ligament reconstruction or osteotomy alone?: Comparative outcome analysis according to the degree of medial compartment osteoarthritis with anterior or posterior cruciate ligament insufficiency.

INTRODUCTION: The purpose of this study was to compare the outcomes of middle-aged patients with anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) insufficiency by assessing different groups: high tibial osteotomy (HTO), HTO with combined ligament reconstruction, and isolated ligament reconstruction according to the alignment change and medial compartment osteoarthritis (OA). MATERIALS AND METHODS: From 2014 to 2019, middle-aged (40-65 years) patients with knee instability were enrolled in this retrospective study. They were categorized into three groups: group I, HTO; group II, HTO with combined ACL or PCL reconstruction; and group III, isolated ligament reconstruction. Radiological outcomes, including Kellgren-Lawrence grade, mechanical femorotibial angle (mFTA), weight-bearing line (WBL) ratio, and posterior tibial slope were compared. Knee stability and clinical outcomes were also compared. RESULTS: Seventy-nine patients completed the final assessment. Group I was older than other two groups (p = 0.006). Groups I and II had a higher body mass index (p = 0.043) and more preoperative varus alignment than group III (p < 0.001). OA severity was ranked in the order of group I, II, and III (p < 0.001). Group I showed more valgus alignment than group II after HTO (p = 0.024 for mFTA and 0.044 for WBL ratio, respectively). Compared to their preoperative status, all three groups showed significant improvement in knee stability (p < 0.001); however, group I showed inferior knee stability regardless of ACL or PCL reconstruction (p < 0.001 and 0.043, respectively). All clinical scores significantly improved in the three groups (p < 0.001), and they showed comparable clinical outcomes in the final assessment. CONCLUSIONS: Our strategy in managing middle-aged patients with knee instability according to the varus alignment and medial degeneration showed favorable stability and clinical outcomes. Middle-aged patients with knee instability should be managed with different strategies depending on their status. LEVEL OF EVIDENCE: Case-control study; Level-III.

Location of Ulnar Nerve Branches to the Flexor Carpi Ulnaris during Surgery for Cubital Tunnel Syndrome.

OBJECTIVE: Cubital tunnel syndrome, the most common ulnar nerve entrapment neuropathy, is usually managed by simple decompression or anterior transposition. One of the concerns in transposition is damage to the nerve branches around the elbow. In this study, the location of ulnar nerve branches to the flexor carpi ulnaris (FCU) was assessed during operations for cubital tunnel syndrome to provide information to reduce operation-related complications. METHODS: A personal series (HJY) of cases operated for cubital tunnel syndrome was reviewed. Cases managed by transposition and location of branches to the FCU were selected for analysis. The function of the branches was confirmed by intraoperative nerve stimulation and the location of the branches was assessed by the distance from the center of medial epicondyle. RESULTS: There was a total of 61 cases of cubital tunnel syndrome, among which 31 were treated by transposition. Twenty-one cases with information on the location of branches were analyzed. The average number of ulnar nerve branches around the elbow was 1.8 (0 to 3), only one case showed no branches. Most of the cases had one branch to the medial head, and one other to the lateral head of the FCU. There were two cases having branches without FCU responses (one branch in one case, three branches in another). The location of the branches to the medial head was 16.3±8.6 mm distal to the medial epicondyle (16 branches; range, 0 to 35 mm), to the lateral head was 19.5±9.5 mm distal to the medial epicondyle (19 branches; range, -5 to 30 mm). Branches without FCU responses were found from 20 mm proximal to the medial condyle to 15 mm distal to the medial epicondyle (five branches). Most of the branches to the medial head were 15 to 20 mm (50% of cases), and most to the lateral head were 15 to 25 mm (58% of cases). There were no cases of discernable weakness of the FCU after operation. CONCLUSION: In most cases of cubital tunnel syndrome, there are ulnar nerve branches around the elbow. Although there might be some cases with branches without FCU responses, most branches are to the FCU, and are to be saved. The operator should be watchful for branches about 15 to 25 mm distal to the medial epicondyle, where most branches come out.