Human primary myoblasts derived from paraspinal muscle reflect donor age as an experimental model of sarcopenia.

BACKGROUND: Low back pain is a general phenomenon of aging, and surgery is an unavoidable choice to relieve severe back pain. The discarded surgical site during surgery is of high value for muscle and muscle-related research. This study investigated the age-dependent properties of patients' paraspinal muscles at the cellular level. METHODS: To define an association of paraspinal muscle degeneration with sarcopenia, we analyzed lumbar paraspinal muscle and myoblasts isolated from donors of various ages (25-77 years). Preoperative evaluations were performed by bioimpedance analysis using the InBody 720, magnetic resonance (MR) imaging of the lumbar spine, and lumbar extension strength using a lumbar extension dynamometer. In addition, the growth and differentiation capacity of myoblasts obtained from the donor was determined using proliferation assay and western blotting. RESULTS: The cross-sectional area of the lumbar paraspinal muscle decreased with age and was also correlated with the appendicular skeletal muscle index (ASM/height2). Human primary myoblasts isolated from paraspinal muscle preserved their proliferative capacity in vitro, which tended to decrease with donor age. The age-dependent decline in myoblast proliferation was correlated with levels of cell cycle inhibitory proteins (p16INK4a, p21CIP1, and p27KIP1) associated with cellular senescence. Primary myoblasts isolated from younger donors differentiated into multinucleate myotubes earlier and at a higher rate than those from older donors in vitro. Age-dependent decline in myogenic potential of the isolated primary myoblasts was likely correlated with the inactivation of myogenic transcription factors such as MyoD, myogenin, and MEF2c. CONCLUSIONS: Myoblasts isolated from human paraspinal muscle preserve myogenic potential that correlates with donor age, providing an in vitro model of sarcopenia.

Analysis of the Effects of COVID-19 on Hip Fractures in Korea Without Lockdown: Interrupted Time Series Analysis Using a Nationwide Cohort.

BACKGROUND: The purpose of this study was to investigate the change in the incidence rate, length of hospital stay (LOS), in-hospital mortality rate, and surgical method of hip fractures during the coronavirus disease 2019 (COVID-19) pandemic in South Korea where lockdown restrictions were not implemented. METHODS: We calculated the expected values of the incidence of hip fractures, in-hospital mortality and LOS of hip fracture patients in 2020 (COVID period) based hip fracture database of the Korean National Health Insurance Review and Assessment (HIRA) during a 9-year period from 2011 to 2019 (pre-COVID period). A generalized estimating equation model with Poisson distribution and logarithmic link function was used to estimate adjusted annual percent change (PC) of incidence rate and 95% confidence intervals (CIs). Then, we compared the annual incidence, in-hospital mortality rate and LOS in 2020 with the expected values. RESULTS: The overall incidence rate of hip fracture in 2020 was not significantly different from the expected value (PC, -5%; 95% CI, -13 to 4; P = 0.280). In women, the incidence rate of hip fracture in age groups over 70 years was smaller than the predicted value (P < 0.001). The in-hospital mortality rate was not significantly different from the expected value (PC, 5%; 95% CI, -8 to 19; P = 0.461). The mean LOS was larger than the expected value by 2% (PC, 2%; 95% CI, 1 to 3; P < 0.001). In intertrochanteric fracture, the proportion of internal fixation was smaller than the predicted value by 2% (PC, -2%; 95% CI, -3 to -1; P < 0.001), and that of hemiarthroplasty was larger than the predicted value by 8% (PC, 8%; 95% CI, 4 to 14; P < 0.001). CONCLUSIONS: In 2020, the incidence rate of hip fracture did not significantly decrease, and in-hospital mortality rate did not significantly increase compared to the expected rates, which were projected based on the HIRA hip fracture data from 2011 to 2019. Only LOS increased slightly.

Effect Modification on Death by Age and Sex in Elderly Hip Fracture.

BACKGROUND: This study compared the effects of hip fractures on mortality according to sex and age in a nationwide cohort of elderly patients with hip fractures and controls. METHODS: Patients with hip fractures and matched controls were selected from the National Health Insurance Service-Senior cohort. Time-dependent propensity score matching was estimated from a Cox proportional hazards model with January 1, 2005, as the baseline and hip fracture as an event. Patients were matched by age and sex to participants at risk of developing a hip fracture at time zero. The effect size is presented as hazard ratio (HR) using a Cox proportional hazards model with a robust variance estimator that accounts for clustering within the matched pairs. RESULTS: Altogether, 14,283 patients with incident hip fractures and 28,566 matched controls were identified. The HR of male sex in hip fractures was 1.31 (95% confidence interval [CI], 1.22-1.40; Pinteraction<0.01). Moreover, the HR of age group in hip fractures was 0.73 (95% CI, 0.66-0.80; Pinteraction<0.01) between the 65 to 74 and 75 to 84 years groups, 0.76 (95% CI, 0.71-0.81; Pinteraction<0.01) between the 75 to 84 and ≥85 years groups, and 0.55 (95% CI, 0.50-0.61; Pinteraction<0.01) between the 65 to 74 and ≥85 years groups. CONCLUSIONS: Male sex increases the risk of death in elderly patients with hip fractures versus matched controls, but the increased risk of death with age in hip fractures was decreased compared to that in matched controls.

Nested Case Control Study on the Risk of Suicide Death in Elderly Patients with Pelvic Fractures Using a Nationwide Cohort.

Background: The aim of this study was to investigate the incidence rate of suicide deaths in elderly patients with pelvic fractures using a nationwide database and to analyze change in the risk of suicide death overtime after pelvic fractures compared to controls. Methods: We used the National Health Insurance Service-Senior cohort (NHIS-Senior) of South Korea. Cases and controls were matched for sex, age, history of hospital admission within 1 year, and presence of depression on the date of suicide death. Controls were collected by random selection at a 1 : 5 ratio from patients at risk of becoming cases when suicide cases were collected. Incident pelvic fractures were identified from the NHIS-Senior as follows: first admission during the observational period (2002-2015) to an acute care hospital with a diagnostic code of International Statistical Classification of Diseases and Related Health Problems, 10th revision S321, S322, S323, S324, S325, or S328 and age 65-99 years. Conditional logistic regression analysis was performed to evaluate the association between pelvic fractures and the risk of suicide death. Results: A total of 2,863 suicide cases and 14,315 controls were identified. Suicide case patients had been more frequently exposed to steroids (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.21-1.45), benzodiazepines (OR, 1.76; 95% CI, 1.61-1.93), and non-steroidal anti-inflammatory drugs (OR, 1.18; 95% CI, 1.07-1.29). Pelvic fractures within 1 year from the date of suicide death were statistically significantly associated with increased risk of suicide (adjusted OR [AOR], 2.65; 95% CI, 1.29-5.45; p = 0.008) compared to controls. The risk of suicide death declined as the incidence date of pelvic fracture was more remote from the date of suicide death: AORs of 2.59 (95% CI, 1.33-5.04; p = 0.005) within 2 years and 2.13 (95% CI, 1.15-3.95; p = 0.017) within 3 years. However, there was no statistical significance in the increased risk of suicide death for pelvic fractures that had occurred ≥ 4 years ago (p > 0.05). Conclusions: Pelvic fractures in the elderly population increased the risk of suicide death within 3 years, suggesting the need for psychiatric support among elderly patients with pelvic fractures.

Comparative Interrupted Time Series Analysis of Long-term Direct Medical Costs in Patients With Hip Fractures and a Matched Cohort: A Large-database Study.

BACKGROUND: Previous studies on medical costs in patients with hip fractures have focused on medical costs incurred for a short period after the injury. However, patients often had comorbidities before their hip fractures that would have affected medical costs even had they not sustained a fracture. Consequently, these studies may have overestimated the costs associated with hip fractures and did not characterize the duration of increased medical costs adequately. Without knowing this crucial information, it is difficult to craft thoughtful health policy to support these patients' needs. QUESTIONS/PURPOSES: (1) To compare the direct medical costs for 5 years before fracture and up to 5 years after injury in a group of patients who underwent hip fracture surgery with a matched group of patients who did not experience a hip fracture, (2) to analyze the duration over which the increased direct medical costs associated with a hip fracture continues, and (3) to analyze whether there is a difference in direct medical costs according to age group using a nationwide claims database in South Korea. METHODS: The National Health Insurance Service Sample cohort in South Korea consisted of 1 million patients who were selected using a systematic, stratified, random sampling method from 48,222,537 individuals on December 31, 2006. Under a compulsory social insurance system established by the National Health Insurance Act, all patients were followed until 2015. Patients with hip fractures and matched controls were selected from the National Health Insurance Service sample of South Korea. Patients with hip fractures were defined as those who were hospitalized with a diagnosis of femoral neck fracture or intertrochanteric fracture and who underwent surgical treatment. We excluded patients with hip fractures before January 1, 2007 to ensure a minimum 5-year period that was free of hip fractures. Patients with hip fractures were matched with patients of the same age and gender at the date of admission to an acute care hospital for surgery (time zero). If patients with hip fractures died during the follow-up period, we performed matching among patients whose difference from the time of death was within 1 month. This method of risk-set matching was repeated sequentially for the next patient until the last patient with a hip fracture was matched. We then sequentially performed 1:5 random sampling for each risk set. A total of 3583 patients in the hip fracture cohort (patients with hip fractures) and 17,915 patients in the matched cohort (those without hip fractures) were included in this study. The mean age was 76 ± 9 years, and 70% were women in both groups. Based on the Charlson comorbidity index score, medication, and medical history, the patients with hip fractures had more comorbidities. Person-level direct medical costs per quarter were calculated for 5 years before time zero and up to 5 years after time zero. Direct medical costs were defined as the sum of that insurer's payments (that is, the National Health Insurance Service's payments), and that patient's copayments, excluding uncovered payments. We compared direct medical costs between patients with hip fractures and the patients in the matched cohort using a comparative interrupted time series analysis. The difference-in-difference estimate is the ratio of the differences in direct medical costs before and after time zero in the hip fracture cohort to the difference in direct medical costs before and after time zero in the matched cohort; the difference in difference estimates were calculated each year after injury. To identify changes in direct medical cost trends in patients with hip fractures and all subgroups, joinpoint regression was estimated using statistical software. RESULTS: The direct medical costs for the patients with hip fractures were higher than those for patients in the matched cohort at every year during the observation period. The difference in direct medical costs between the groups before time zero has increased every year. The direct medical costs in patients with hip fractures was the highest in the first quarter after time zero. Considering the differential changes in direct medical costs before and after time zero, hip fractures incurred additional direct medical costs of USD 2514 (95% CI 2423 to 2606; p < 0.01) per patient and USD 264 (95% CI 166 to 361; p < 0.01) per patient in the first and second years, respectively. The increase in direct medical costs attributable to hip fracture was observed for 1.5 to 2 years (difference-in-difference estimate at 1 year 3.0 [95% CI 2.8 to 3.2]; p < 0.01) (difference-in-difference estimate at 2 years 1.2 [95% CI 1.1 to 1.3]; p < 0.01; joinpoint 1.5 year). In the subgroups of patients younger than 65, patients between 65 and 85, and patients older than 85 years of age, the increase in direct medical costs attributable to hip fracture continued up to 1 year (difference-in-difference estimate ratio at 1 year 2.7 [95% CI 2.1 to 3.4]; p < 0.01; joinpoint 1 year), 1.5 to 2 years (difference-in-difference estimate ratio at 1 year 2.8 [95% CI 2.6 to 3.1]; p < 0.01; difference-in-difference estimate ratio at 2 years 1.2 [95% CI 1.1 to 1.3]; p < 0.01; joinpoint 1.5 years), and 39 months to 5 years (difference-in-difference estimate ratio at 1 year 5.2 [95% CI 4.4 to 6.2]; p < 0.01; difference-in-difference estimate ratio at 5 years 2.1 [95% CI 1.4 to 3.1]; p < 0.01; joinpoint 39 months) from time zero, respectively. CONCLUSION: The direct medical costs in patients with hip fractures were higher than those in the matched cohort every year during the 5 years before and after hip fracture. The increase in direct medical costs because of hip fractures was maintained for 1.5 to 2 years and was greater in older patients. Based on this, we suggest that health policies should focus on patients' financial and social needs, with particular emphasis on the first 2 years after hip fracture with stratification based on patients' ages. LEVEL OF EVIDENCE: Level II, economic analysis.

Population-based Analysis for Risk of Suicide Death in Elderly Patients after Osteoporotic Fracture: a Nested Case-Control Study.

BACKGROUND: The purpose of study was to investigate the incidence rate of suicide in elderly patients with osteoporotic fractures in a nested case-control model and to analyze the change in the risk of suicide death over time after each osteoporotic fracture. METHODS: We used the National Health Insurance Service-Senior cohort of South Korea. Suicide cases and controls were matched based on sex and age at the index date. Controls were randomly selected at a 1:5 ratio from the set of individuals who were at risk of becoming a case at the time when suicide cases were selected. Conditional logistic regression analysis was performed to evaluate the association between each type of osteoporotic fracture and the risk of suicide death. RESULTS: Three thousand seventy suicide cases and 15,350 controls were identified. Patients with hip fracture showed an increased risk of suicide death within 1 year of fracture (adjusted odds ratio [aOR] = 2.64; 95% confidence interval [CI], 1.57-4.46; P < 0.001) compared to controls. However, the increased risk of suicide death in patients with hip fracture lasted up to 2 years (aOR = 1.59; 95% CI, 1.04-2.41; P = 0.031). Spine fracture increased the risk of suicide deaths for all observation periods. There was no evidence that humerus fracture increased the risk of suicide death during the observational period. Radius fracture increased only the risk of suicide death within 2 years of fracture (aOR = 1.43; 95% CI, 0.74-2.77; P = 0.282). CONCLUSION: There were noticeable differences in both degree and duration of increased suicide risks depending on the type of osteoporotic fracture. Mental stress and suicide risk in elderly patients after osteoporotic fracture should be assessed differently depending on the types of fracture.

What Is the Difference in the Risk of Suicide Death Between Spine Fracture in Patients Older Than 65 Years and Matched Controls? A Large-database Study from South Korea.

BACKGROUND: Pain and kyphotic deformity after spinal fractures can result in a decrease in a patient's physical function and quality of life. Furthermore, physical illness, such as respiratory compromise, or mental illness, including depression, may be exacerbated by a spinal fracture. Complications caused by spinal fractures and old age are risk factors for suicide, but studies on these patients are rare. QUESTIONS/PURPOSES: (1) What is the incidence rate of death by suicide after a spinal fracture in patients older than 65 years? (2) How much does the risk of death by suicide increase in patients older than 65 years who have spine fractures compared with well-matched controls? (3) How does this risk change as a function of increasing time after injury? METHODS: Spinal fractures in patients older than 65 years and matched controls were selected from the National Health Insurance Service-Senior cohort (NHIS-Senior) of South Korea. The NHIS-Senior consists of 558,147 people selected by 10% simple random sampling method from a total of 5.5 million people 60 and older in 2002; all people were followed through 2015. A total of 31,357 patients with spine fractures and their 62,714 matched controls remained in the study. The mean follow-up time was 4.3 ± 3.0 years (135,229 person-years) in the spine fracture group and 4.6 ± 3.0 years (290,096 person-years) in the matched control group. We matched the groups for demographic factors such as age, gender, Charlson Comorbidity Index score, medication history, medical history, preoperative disability, number of hospital admissions, as well as socioeconomic factors such as household income level, residential district, and type of national health insurance using a 1:2 risk set propensity score matching by a nearest-neighbor matching algorithm with a maximum caliber of 0.1 of the hazard components. The incidence rate of suicide and the 95% confidence interval were calculated based on a generalized linear model with a Poisson distribution. The effect size was presented as a hazard ratio (HR) using Cox's proportional hazard model with robust variance estimator that accounts for clustering within matched pairs. RESULTS: The overall risk of death by suicide throughout the surveillance period, expressed as an incidence rate, was 116 per 100,000 person-years in spinal fracture (157 deaths by suicide over 135,229 person-years). Throughout the entire surveillance period, the risk of death by suicide was greater among patients with spinal fractures than it was in the control group (HR 1.8 [95% CI 1.5 to 2.2]; p < 0.01). This difference was greatest in the first 365 days after the fracture (HR 2.5 [95% CI 1.6 to 3.8]; p < 0.01) (45 deaths by suicide, incidence rate: 156 per 100,000 person-years in spinal fracture). The risk of suicide death in patients with spine fracture from 365 days to the last follow-up was also higher than that of matched controls (HR 1.6 [95% CI 1.3 to 2.1]; p < 0.01). CONCLUSIONS: Considering the substantially increased risk of death by suicide in patients with spine fractures who are older than 65 years, surgeons should consider offering psychiatric evaluation and management more frequently, particularly in patients with chronic pain, functional disability, and depressive mood. Future studies should investigate the underlying causes of suicide, such as deteriorating socioeconomic support or depression, and whether early initiation of psychological support after injury can reduce the suicide rate. LEVEL OF EVIDENCE: Level III, prognostic study.

The Influence of Renal Dialysis on All-Cause Mortality in Older Patients with Hip Fracture: a Korean Nationwide Cohort Study.

BACKGROUND: The purpose of this study was to analyze the all-cause mortality rate over time after elderly hip fracture in end-stage renal disease (ESRD) patients with dialysis, using a Korean nationwide claims database. METHODS: This retrospective nationwide study identified subjects from the Korean National Health Insurance Service-Senior cohort (NHIS-Senior). The NHIS-Senior (total of 588,147 participants) was constructed by 10% random sampling and was designed to represent the elderly living in Korea. Subjects were patients aged 65-99 years who underwent surgical treatment for femoral neck fractures or intertrochanteric fractures. A generalized estimating equation model with Poisson distribution and logarithmic link function was used to estimate adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) to measure associations between renal dialysis and cumulative mortality in various time frames. RESULTS: The total number of patients included in this study was 16,818. These patients were divided into two groups: 116 (0.69%) in the dialysis group and 16,702 (99.31%) in the no-dialysis group. The mean length of hospital stay was 43.87 ± 48.45 days in the dialysis group and 36.29 ± 37.49 days in the no-dialysis group (P = 0.095). The effect of renal dialysis on all-cause mortality was 2.29-fold (aRR; 95% CI, 1.29-4.06; P = 0.005) within 30 days and 1.72-fold (aRR; 95% CI, 1.34-2.21; P < 0.001) within 1-year after hip fracture compared to the no-dialysis group. And, the effect of renal dialysis of in-hospital mortality was 2.72-fold (aRR; 95% CI, 1.71-4.33; P < 0.001) compared to the no-dialysis group. CONCLUSION: Elderly patients who underwent dialysis have very high mortality rates after hip fracture. Therefore, it is considered that postoperative care through multidisciplinary management and understanding of pathophysiology for the ESRD patients is necessary.

Suicide in Elderly Patients with Hip Fracture: A South Korean Nationwide Cohort Study.

BACKGROUND: The purpose of the present study was to evaluate the incidence rate (IR) of suicide in elderly patients with hip fracture on the basis of a nationwide cohort and to analyze the change in the hazard ratio for suicide after hip fracture over time in comparison with a control group. METHODS: Patients with hip fracture and their matched controls were selected from the National Health Insurance Service-Senior cohort (NHIS-Senior) of the Republic of Korea. The NHIS-Senior consists of 558,147 people selected by a 10% simple random-sampling method from a total of 5.5 million subjects ≥60 years of age in 2002. Risk-set matching (1:2) on the propensity score was performed with use of a nearest neighbor matching algorithm with a maximum caliper of 0.1 for the hazard components. The IR of suicide and 95% confidence interval (CI) were calculated on the basis of a generalized linear model with a Poisson distribution. The effect size was presented as a hazard ratio (HR) with use of the Cox proportional-hazard model with a robust variance estimator that accounts for clustering within matched pairs. RESULTS: A total of 11,477 patients with hip fracture and 22,954 matched controls were included. The mean duration of follow-up was 4.59 years, generating 158,139 person-years. During follow-up, a total of 170 suicides were identified. Comparisons at up to 180 days and 365 days showed that patients with hip fracture were at higher risk for suicide than matched controls (p = 0.009 and 0.004, respectively; stratified log-rank test). During the first 180 days of follow-up, 14 suicides were identified in patients with hip fracture during 11,152 person-years (IR, 266.1 per 100,000 person-years; 95% CI, 157.6 to 449.4). Patients with hip fracture were 2.97 times more likely to kill themselves than their matched controls during the same period (HR = 2.97; 95% CI, 1.32 to 6.69). CONCLUSIONS: Hip fracture in elderly patients increased suicide risk within a year. A new approach to psychiatric evaluation and management is needed in elderly patients with hip fracture. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Sarcopenia and Back Muscle Degeneration as Risk Factors for Back Pain: A Comparative Study.

STUDY DESIGN: Case-control study. PURPOSE: To investigate the independent associations of back pain with sarcopenia and with back muscle degeneration, and to introduce a new risk index for back muscle degeneration. OVERVIEW OF LITERATURE: The Asian Working Group for Sarcopenia recommends diagnosis using handgrip strength, gait speed, and skeletal muscle mass. However, these criteria do not strongly reflect back muscle degeneration. METHODS: Patients who completed a questionnaire on back-pain between October 2016 and October 2017 were enrolled in this study. Appendicular skeletal muscle index (ASMI), cross-sectional area (CSA) index, fatty infiltration (FI) rate of the paraspinal muscles, and lumbar extensor strength index (LESI) were measured and compared between no back-pain and back-pain group. Correlations between LESI and ASMI, CSA index, and FI rate were analyzed. The back-pain group was further divided according to ASMI into sarcopenia and non-sarcopenia subgroups and by our newly developed back muscle degeneration risk index based on correlation coefficients between LESI and CSA index, FI rate. Differences in ASMI, CSA index, FI rate, LESI, and Visual Analog Scale (VAS) score between subgroups were analyzed. RESULTS: The ASMI, CSA index, FI rate, and LESI differed significantly between back-pain and pain-free groups. The LESI demonstrated the strongest correlation with FI rate. There were no significant differences in VAS score and back muscle degeneration index in the back-pain group when divided according to the presence of sarcopenia. However, there was a significant difference in VAS score between back-pain patients when classified according to high and low back muscle degeneration risk index. CONCLUSIONS: We suggest that the degree of back pain is more strongly associated with back muscle degeneration than with sarcopenia. This back muscle degeneration risk index, reflecting both back muscle morphology and function, could be a useful parameter for evaluation of back pain and muscle degeneration.

The effect of surgery type on mortality in elderly patients with pertrochanteric femoral fracture: A Korean nationwide cohort study.

BACKGROUND/OBJECTIVE: The purpose of this study is to analyze the effect of surgical methods on mortality and the relative risk of patients who underwent internal fixation (IF) or hemiarthroplasty (HA) after being diagnosed as a pertrochanteric fracture over 65 years old in a Korean nationwide cohort with a single insurance medical system. METHODS: The Korean National Health Insurance Service-Senior cohort (NHIS-Senior, NHIS-2018-2-111) was used in this study. The eligibility criteria for incident hip fracture patients were the following: (1) first-time admission to acute care hospitals (index admission) with pertrochanteric fracture (ICD-10 S721), (2) three years of hip fracture-free period, (3) recipients of typical surgeries including IF, HA, (4) age between 65 and 99. RESULTS: a total of 7223 patients were enrolled in the cohort. There were 1662 patients (23%) in the HA group and 5561 patients (77%) in the IF group. Mortality rates of the IF group and HA group were 13.46 and 17.94 cases per 100 person-years, respectively. In the multivariable-adjusted Cox proportional hazard model, the HA group had 1.22 times more hazard of all-cause mortality than IF group (aHR 1.22, 95% CI 1.13-1.32). In subgroup analysis, aged 65-79 and female patients showed a prominent association between surgery type and mortality (aHR 1.52, 95% CI 1.29-1.79). CONCLUSIONS: In patients with pertrochanter fracture over 65 years, 1.22-fold mortality rate was observed when HA was performed compared to that of IF, and the difference in mortality was particularly prominent within 1-year after surgery.

Arthroscopic Assessment of Cartilage Healing Status after Treatment of Tibial Plateau Fracture.

BACKGROUND: There are a few reports on the healing status of the cartilage after the treatment of tibial plateau fracture. In this study, we analyzed the healing status of articular cartilage using second-look arthroscopy with clinical and radiological results from patient's in schatzker Type I, II, and III tibial plateau fracture. MATERIALS AND METHODS: 43 patients operated between January 2011 and December 2013 were included in this retrospective study. Radiological evaluation was performed by comparing simple radiographs from the preoperative, postoperative, and final followup period. Clinical evaluations were performed using the Knee Society Knee Score (KSKS) and the Knee Society Functional Score (KSFS). Moreover, second-look arthroscopic evaluation was performed during implant removal, and cartilage healing status was classified according to the International Cartilage Repair Society grading system (ICRS). RESULTS: In all 43 patients, bony union was achieved with a mean duration of 13.7 weeks. The degree of cartilage healing was poor when the step-off was high (P = 0.016). Furthermore, even in cases with satisfactory step-off <2 mm, there was no case with complete cartilage healing. Between ICRS grade and clinical results, the respective Pearson coefficient for KSKS and KSFS were r = -0.62 and r = -0.59 indicating mean statistically significant negative correlations (P = 0.001). CONCLUSION: Even though step off was reduced anatomically and clinical outcome was excellent or good, there was not always complete cartilage healing in a followup on second-look arthroscopy. Therefore, we focused on not only radiologic and clinical outcome but also the actual status of cartilage with second-look arthroscopy.

Biomechanical Evaluation of Internal Fixation of Pauwels Type III Femoral Neck Fractures: A Systematic Review of Various Fixation Methods.

BACKGROUND: The purpose of this systematic review was to investigate various fixation methods or implants used in the treatment of Pauwels type III femoral neck fractures. METHODS: PubMed Central, OVID Medline, Cochrane Collaboration Library, Web of Science, Embase, and AHRQ databases were searched to identify relevant studies published until August 2017 with English language restriction. Studies were selected on the basis of the following inclusion criteria: biomechanical study of Pauwels type III femoral neck fractures and the use of dynamic hip screw (DHS) or multiple screw fixation or other devices for fixation of the fracture. RESULTS: A total of 15 studies were included in the systematic review. Eight studies were conducted using cadavers, six studies using sawbones, and one using a finite element model. During the mechanical testing, each study measured mechanical stiffness, failure to cyclic loading, failure to vertical loading of each fixation device. DHS was included in 11 studies, multiple screw fixation in 10 studies, and other devices in six studies. Baitner et al. and Samsami et al. reported that the mechanical stiffness of DHS was superior to three inverted triangular screw fixation. Hawks et al. and Gumustas et al. reported that using a transverse calcar screw can withstand vertical loading better than three inverted triangular screw fixation. In addition, there were some studies where instruments such as Intertan nail, locking plate or other devices showed excellent biomechanical properties. CONCLUSIONS: There are a variety of methods and instruments for fixation of the Pauwels type III fractures. However, it is difficult to conclude that any method is more desirable because there are advantages and disadvantages to each method. Therefore, we should pay attention to the implant choice and consider adequate weight bearing affecting the stiffness of the implant.

Gait analysis after total hip arthroplasty using direct anterior approach versus anterolateral approach: a systematic review and meta-analysis.

BACKGROUND: Comparative studies of total hip arthroplasty using the direct anterior approach (DAA) compared with the anterolateral approach (ALA) by gait analysis compared the results of the two groups, the damage to the abductor muscle, with objective and detailed kinematic as well as kinetic data of actual gait. The purpose of this systematic review was to analyze the differences in gait such as time-dependent parameters, kinetics, and kinematics after THA using the DAA compared with ALA. METHODS: PubMed Central, OVID Medline, Cochrane Collaboration Library, Web of Science, EMBASE and AHRQ carried out a comprehensive search for all relevant randomized controlled trials and comparative studies, up to December 2018. Based on the following criteria, studies were selected: 1) study design: randomized controlled trials or non-randomized comparative studies; 2) study population: patients with primary osteoarthritis or avascular necrosis; 3) intervention: total hip arthroplasty by DAA or ALA; 4) Kinetic and kinematic data after gait analysis in the plains during postoperative follow-up. RESULTS: Of the 148 studies, 7 randomized controlled trials and 5 comparative studies were finally included in this systematic review. The peak hip flexion within 3 months after surgery was described in two studies and was significantly higher in the DAA group. (OR = 1.90; 95% CI [1.67,2.13]; P < 0.01, Z = 16.18). The gait speed within 3 months after surgery was reported in 3 studies and was significantly higher in the DAA group than in the ALA group. (SMD = 0.17; 95% CI [0.12,0.22]; P < 0.01, Z = 6.62) There was no difference between the two groups in stride length, step length, and hip range of motion in sagittal plane. CONCLUSIONS: In this meta-analysis, gait speed and peak hip flexion within 3 months after surgery were significantly higher in the DAA group than in the ALA group. Despite a few significant differences between two approaches, determining whether the reported differences in terms of postoperative gait values are clinically meaningful remains a substantial challenge.

Comparison between Cementless and Cemented Bipolar Hemiarthroplasty for Treatment of Unstable Intertrochanteric Fractures: Systematic Review and Meta-analysis.

PURPOSE: This study was conducted to compare cemented and cementless bipolar hemiarthroplasty in elderly patients with unstable intertrochanteric fractures via meta-analysis and systematic review of relevant studies. MATERIALS AND METHODS: Systematic review and meta-analysis were performed on 31 available clinical studies; 19 of these studies used cemented stems, 12 used cementless stems, one used both types of stems, and two studies involved a comparative analysis of both stem types. RESULTS: There were statistically significant differences in rates of leg length discrepancy (LLD) greater than 1 cm between the cemented (event rate, 0.089) and cementless groups (event rate, 0.015 and 0.047; P=0.03). CONCLUSION: Cemented bipolar hemiarthroplasty and cementless bipolar hemiarthroplasty performed on elderly patients with unstable intertrochanteric fracture revealed similar mortality and complication rates; however, the rate of LLD greater than 1 cm was significantly higher in the cemented group compared with the cementless group.

Mobile bearing medial unicompartmental knee arthroplasty in patients whose lifestyles involve high degrees of knee flexion: A 10-14year follow-up study.

BACKGROUND: Because Asian populations have different lifestyles, such as squatting and sitting on the floor, from those of Western populations, it is possible that the clinical results and survival rate of unicompartmental knee arthroplasty (UKA) for Asian patients may be different. This study described outcomes of mobile bearing medial UKA for Korean patients. METHODS: A total of the 164 knees treated with mobile bearing UKAs in 147 patients (14 males and 133 females) were reviewed. The mean follow-up period was 12.1years (range 10.1-14). RESULTS: The clinical outcomes, such as the Hospital for Special Surgery Knee score, the Oxford Knee Score and the Knee Society rating system, showed statistically significant improvement from pre-operative to final follow-up (P<0.05). A total of 26 UKAs (15.8%) required revision; the most common reason was bearing dislocation. The 95% confidence interval of survival rate at 12years was 84.1%, with revision for any reason as the end point. CONCLUSIONS: Minimally invasive mobile bearing UKA in Asian patients who required high degrees of knee flexion showed rapid recovery and good clinical outcome. However, they also showed relatively high rates of bearing dislocation and aseptic loosening. Therefore, mobile bearing UKA should only be performed in patients whose lifestyle involves high flexions after carefully considering these risks and benefits.

Treatment of Advanced Kienböck Disease With a Vascularized Radial Bone Flap Wrapped in the Pronator Quadratus.

PURPOSE: In the present study, we aimed to assess the radiologic and clinical outcomes after excision of the lunate, insertion of a vascularized radial bone flap wrapped in the pronator quadratus, and distraction with an external fixator of the joint, for the treatment of avascular necrosis of the lunate with carpal height collapse, fragmentation, and perilunar osteoarthritic changes. MATERIALS AND METHODS: From May 2006 to July 2014, a total of 25 patients (13 men and 12 women; mean age, 38.7 years; age range, 28-52 years) with advanced Kienböck disease were treated with excision of the lunate and insertion of a vascularized radial bone flap wrapped in the pronator quadratus, followed by distraction with an external fixator of the joint; all these patients met our inclusion criteria, including symptomatic avascular necrosis of the lunate with carpal collapse and osteoarthritis of the wrist. We evaluated the scaphocapitate angle for radiologic assessment. Moreover, the overall clinical results were graded by using the wrist range of motion, modified Mayo wrist score, and disabilities of the arm, shoulder, and hand score. RESULTS: All the patients exhibited improved symptoms, and subsequently returned to their work and recreational activities. The mean scaphocapitate angles and carpal height ratio improved from 33.7 degrees (range, 32.1-35.7 degrees) and 0.46 degrees (range, 0.42-0.51 degrees) preoperatively to 56.3 degrees (range, 54.7-59.8 degrees) and 0.50 degrees (range, 0.46-0.56 degrees) at the follow-up, respectively. The final average range of motion was as follows: wrist flexion, 73 degrees (range, 62-81 degrees); and extension, 76 degrees (range, 69-88 degrees). The average postoperative modified Mayo wrist score and disabilities of the arm, shoulder, and hand score were 91 points (range, 80-100 points) and 11 points (range, 2-24 points), respectively. CONCLUSION: We suggest that the excision of the lunate and insertion of a vascularized radial bone flap wrapped in the pronator quadratus, followed by distraction with an external fixator of the joint, is a reliable method for the treatment of Kienböck disease with collapse or fragmentation of the lunate, and achieves high functional scores, increased range of movement, and relief of pain, without any complications.

Conservative Treatment Is Sufficient for Acute Distal Radioulnar Joint Instability With Distal Radius Fracture.

Treatments for acute distal radioulnar joint (DRUJ) instability with distal radius fracture vary from conservative to operative treatment, although it seems to be no consensus regarding which treatment is optimal. This prospective randomized study was designed to compare the clinical outcomes for operative and conservative treatment of acute DRUJ instability with distal radius fracture, according to the presence or absence and type of ulnar styloid process fracture and the degree of its displacement. Between July 2008 and February 2013, we enrolled 157 patients who exhibited an unstable DRUJ during intraoperative manual stress testing (via the ballottement test) after fixation of the distal radius. Patients were classified according to the type of the ulnar styloid process fracture, using preoperative wrist radiography, and each group was divided into subgroups, according to their treatment method. We then compared the clinical outcomes between the conservative and operative treatments, using their range of motion; Disabilities of the Arm, Shoulder, and Hand score; modified Mayo wrist score; and grip strength. At 3 months after surgery, among patients without ulnar styloid process fracture, the flexion-extension range was 79 ± 15° after supination sugar-tong splinting (group A-1), 91 ± 14° after DRUJ transfixation (group A-2), and 89 ± 10° after arthroscopic triangular fibrocartilage complex repair (group A-3); the operative treatments provided greater joint motion ranges than conservative treatment. The groups with ulnar styloid process fractures at the tip (group B) or base (group C) also exhibited better clinical outcomes after the operative treatments, compared with after the conservative treatment. However, at the final follow-up, groups A-1, A-2, and A-3 exhibited similar flexion-extension ranges (122 ± 25°, 119° ± 18°, and 120° ± 16°, respectively) and modified Mayo wrist scores (87 ± 7, 89 ± 8, and 85 ± 9). Thus, the conservative and operative treatments provided similar long-term outcomes, and similar results were observed for patients with ulnar styloid process fracture at the tip or base. The average splint application period for patients who underwent conservative treatment was 6.6 weeks (range, 4-9 weeks). In our practice, conservative treatment (supination sugar-tong splinting) and surgical treatments provided similar long-term outcomes for acute DRUJ instability with distal radius fracture.

Screw-Home Movement of the Tibiofemoral Joint during Normal Gait: Three-Dimensional Analysis.

BACKGROUND: The purpose of this study was to evaluate the screw-home movement at the tibiofemoral joint during normal gait by utilizing the 3-dimensional motion capture technique. METHODS: Fifteen young males and fifteen young females (total 60 knee joints) who had no history of musculoskeletal disease or a particular gait problem were included in this study. Two more markers were attached to the subject in addition to the Helen-Hayes marker set. Thus, two virtual planes, femoral coronal plane (P f ) and tibial coronal plane (P t ), were created by Skeletal Builder software. This study measured the 3-dimensional knee joint movement in the sagittal, coronal, and transverse planes of these two virtual planes (P f and P t ) during normal gait. RESULTS: With respect to kinematics and kinetics, both males and females showed normal adult gait patterns, and the mean difference in the temporal gait parameters was not statistically significant (p > 0.05). In the transverse plane, the screw-home movement occurred as expected during the pre-swing phase and the late-swing phase at an angle of about 17°. However, the tibia rotated externally with respect to the femur, rather than internally, while the knee joint started to flex during the loading response (paradoxical screw-home movement), and the angle was 6°. CONCLUSIONS: Paradoxical screw-home movement may be an important mechanism that provides stability to the knee joint during the remaining stance phase. Obtaining the kinematic values of the knee joint during gait can be useful in diagnosing and treating the pathological knee joints.