Association of general and central obesity, and their changes with risk of knee osteoarthritis: a nationwide population-based cohort study.

In this study, we aimed to evaluate the association between general and central obesity, and their changes with risk of knee osteoarthritis (OA) using retrospective cohort data collected from the Korean National Health Insurance Service. We studied 1,139,463 people aged 50 and over who received a health examination in 2009. To evaluate the association between general and/or central obesity and knee OA risk, a Cox proportional hazard models were used. Additionally, we investigate knee OA risk according to the change in obesity status over 2 years for subjects who had undergone health examinations for 2 consecutive years. General obesity without central obesity (HR 1.281, 95% CI 1.270-1.292) and central obesity without general obesity (HR 1.167, 95% CI 1.150-1.184) were associated with increased knee OA risk than the comparison group. Individuals with both general with central obesity had the highest risk (HR 1.418, 95% CI 1.406-1.429). This association was more pronounced in women and younger age group. Remarkably, the remission of general or central obesity over two years was associated with decreased knee OA risk (HR 0.884; 95% CI 0.867-0.902; HR 0.900; 95% CI 0.884-0.916, respectively). The present study found that both general and central obesity were associated with increased risk of knee OA and the risk was highest when the two types of obesity were accompanied. Changes in obesity status have been confirmed to alter the risk of knee OA.

Association between knee osteoarthritis and the risk of cardiovascular disease and the synergistic adverse effects of lack of exercise.

We aimed to determine whether knee OA is associated with CVD risk and all-cause death and to evaluate whether the association differs by exercise behavior. We used Korea National Health Insurance Service (KNHIS) database and included 201,466 participants (7572 subjects diagnosed with knee OA) who underwent health screening between 2009 and 2015. Those who had been diagnosed with knee OA or CVD before the index year were excluded. Cox proportional hazard models were used after adjusting for sociodemographic and CVD risk factors to evaluate the association between knee OA and CVD risk and all-cause death. Stratification analysis was further performed to determine the effect of exercise behavior on this relationship. During a median follow-up of 7.06 ± 2.24 years, 8743 CVD (2510 MI and 6553 stroke) cases developed. Individuals with knee OA had increased risks of CVD [hazard ratio (HR) 1.26, 95% confidence interval (CI) 1.15-1.38], myocardial infarction (MI) (HR 1.20, 95% CI 1.00-1.44), and stroke (HR 1.29, 95% CI 1.16-1.43) compared with those without knee OA. Those with knee OA who did not exercise had an increased risk of CVD (HR 1.25, 95% CI 1.11-1.40), whereas no significant increased CVD risk was observed in those with knee OA who exercised at least once a week (HR 1.11, 95% CI 0.96-1.28). There was no association between knee osteoarthritis and all-cause death. Knee OA was independently associated with an increased risk of CVD. Lack of exercise might have a synergistic adverse effect on the association between knee OA and CVD.

Effectiveness of controlled telescoping system for lateral hip pain caused by sliding of blade following intramedullary nailing of trochanteric fracture.

INTRODUCTION: The purpose of this study was to demonstrate the effectiveness of controlled telescoping system for lateral hip pain caused by sliding of the blade following intramedullary nailing of trochanteric fractures. MATERIALS AND METHODS: A retrospective cohort study was performed to compare the controlled telescoping system (Compression Hip Nail; CHN) with the conventional sliding system (Proximal Femoral Nail Antirotation; PFNA) for trochanteric fractures. 74 cases in the PFNA group and 77 cases in the CHN group were included from two university hospitals in this study. All patients had a minimum of 12-month follow up period. Lateral hip pain was evaluated and operation time and blood loss during the surgery were measured. The fracture classification was evaluated. The quality of postoperative reduction and other complications after surgery were also evaluated and tip-apex distance (TAD), telescoping and lateral protrusion of the blade and lag screw were measured. RESULTS: The mean age was 78.5 years in the PFNA group and 74.7 years in the CHN group (p=0.25). The mean telescoping was 19.2mm in the PFNA group and 10.7mm in the CHN group (p<0.001). The mean length of lateral protrusion was 10.5mm in the PFNA group and 2.5mm in the CHN group (p<0.001). Twenty-eight patients in the PFNA group complained of lateral hip pain, whereas 12 patients in the CHN group did (p=0.002). These four variables showed statistically significant differences between the PFNA and CHN groups (p<0.05). The length of lateral protrusion was the only variable significantly related to lateral hip pain through multivariate logistic regression analysis (p=0.045). CONCLUSIONS: The degree of lateral protrusion was mainly related to lateral hip pain. Therefore, controlled telescoping would help to decrease lateral hip pain by decreasing the lateral protrusion beyond the lateral femoral cortex.

Changes of spinopelvic parameters in different positions.

INTRODUCTION: To observe changes of spinopelvic parameters and the presence of pelvic incidence (PI) variation in different positions, and the accuracy of PI compared with CT scan. MATERIALS AND METHODS: Patients with standing whole-spine radiograph, CT scan of the pelvic bone, and MRI of the lumbar spine done within a few days were included. The pelvic [pelvic tilt (PT), sacral slope (SS), and PI] and spinal [lumbar lordosis (LL)] parameters were measured by two different observers. RESULTS: The PIs from radiograph were significantly greater than those from CT in both observers. By adopting the upper limit of the confidence interval and the agreement of two observers on grouping, patients were categorized into two subgroups (SG1, with less PI change; SG2, with higher PI change). The PT and LL values decreased, whereas SS increased significantly from standing to supine positions in SG1. Significantly decreased PT and PI from standing to supine were observed in SG2. All pelvic parameters and the sagittal vertical axis on radiograph, and the LL amount on MRI were significantly greater in SG2 than in SG1. CONCLUSIONS: Majority of patients demonstrated alignment changes of unchanged PI with decreased PT and LL, and increased SS from standing to supine; however, decreased PT and PI and fixed SS and LL were also demonstrated. Patients with higher PI change have high values in three pelvic parameters and sagittal vertical axis, and fixed LL.

Two-dimensional Morphological Characteristics of the Distal Radius on Axial Magnetic Resonance Image and the Effects on Distal Screw Length.

BACKGROUND: Detection of dorsal cortical penetration of distal locking screws is difficult owing to the irregular shape of the dorsal surface of the distal radius. This study was designed to analyze two-dimensional morphological characteristics of the distal radius on axial magnetic resonance image, and to suggest a guideline for evaluation of screw length in distal radius fractures on the fluoroscopic or plain X-ray true lateral image. METHODS: Anteroposterior length and lateral width of the distal radius, distance between the highest and the lowest point of the dorsal cortex (deceptive length), and widths of the first to second (hazard zone) and the third to fifth extensor compartments (safe zone) at the Lister tubercle level were measured on 104 axial magnetic resonance images by two hand surgeons. RESULTS: The mean length and width of the distal radius at the Lister tubercle level were 22.96 mm and 30.42 mm, respectively. The mean hazard zone and safe zone widths were 8.72 mm and 19.43 mm, respectively. The mean deceptive length was 4.07 mm and the deceptive length did not have a relationship with height, sex, and age of subjects. CONCLUSIONS: We suggest that 4 mm be used as a reference value for the evaluation screw length at the safe zone. If the vertical distance between a distal screw tip and the peak of the Lister tubercle is lesser than 4 mm on a fluoroscopic or plain X-ray true lateral image, dorsal cortical penetration should be suspected. When dorsal cortical penetration at the hazard zone is suspected, both oblique or pro-supination views should be checked.

Survey of Preferences in Patients Scheduled for Carpal Tunnel Release Using Conjoint Analysis.

BACKGROUND: This study aimed to investigate the preferences of patients scheduled for carpal tunnel release using conjoint analysis and also introduce an example of how to apply a conjoint analysis to the medical field. The use of conjoint analysis in this study is new to the field of orthopedic surgery. METHODS: A total of 97 patients scheduled for carpal tunnel release completed the survey. The following four attributes were predefined: board certification status, distance from the patient's residency, medical costs, and waiting time for surgery. Two plausible levels for each attribute were assigned. Based on these attributes and levels, 16 scenarios were generated (2 × 2 × 2 × 2). We employed 8 scenarios using a fractional factorial design (orthogonal plan). Preferences for scenarios were then evaluated by ranking: patients were asked to list the 8 scenarios in their order of preference. Outcomes consisted of two results: the average importance of each attribute and the utility score. RESULTS: The most important attribute was the physician's board certificate, followed by distance from the patient's residency to the hospital, waiting time, and costs. Utility estimate findings revealed that patients had a greater preference for a hand specialist than a general orthopedic surgeon. CONCLUSIONS: Patients considered the physician's expertise as the most important factor when choosing a hospital for carpal tunnel release. This suggests that patients are increasingly seeking safety without complications as interest in medical malpractice has increased.