Risk factors associated with failure of total ankle arthroplasty: a nationwide cohort study.

We conducted a nationwide population-based cohort study to identify the risk factors associated with failure of total ankle arthroplasty (TAA). We included 2,914 subjects who underwent primary TAA between January 1, 2010, and December 31, 2016, utilizing the database of the Korean National Health Insurance Service. Failure of TAA was defined as revision TAA or arthrodesis procedures. An increased risk of TAA failure was observed in the < 65 age group versus the ≥ 75 age group [adjusted hazard ratios (aHR) 2.273, 95% confidence interval (CI) 1.223-4.226 in the 60-64 age group; aHR 2.697, 95% CI 1.405-5.178 in the 55-59 age group; aHR 2.281, 95% CI 1.145-4.543 in the 50-54 age group; aHR 2.851, 95% CI 1.311-6.203 in the < 50 age group]. Conversely, the ≥ 65 age group displayed no increase in the risk of TAA failure. The risk of TAA failure was increased in the severely obese group with body mass index (BMI) of ≥ 30 kg/m2 versus the normal BMI group (aHR 1.632; 95% CI 1.036-2.570). This population-based longitudinal study demonstrated that age < 65 years and BMI of ≥ 30 kg/m2 were associated with increased risk of TAA failure.

Hip-to-calcaneus alignment differs from hip-to-talus alignment in patients with genu varum deformity.

PURPOSE: To (1) compare the weight-bearing line (WBL) ratios of the knee joints measured using the conventional (hip-to-talus radiographs, HTRs) and novel (hip-to-calcaneus radiographs, HCRs) orthoradiograms, (2) compare the hip-knee-ankle (HKA) angle between cases with < 5% and > 5% differences in WBL ratios between two orthoradiograms, and (3) investigate the optimal cutoff value (COV) of the HKA angle causing inconsistency in the orthoradiograms. METHODS: Sixty limbs of 31 patients with HTR and HCR records were retrospectively reviewed. After drawing the mechanical axis on each radiograph, the WBL ratios of the knees were calculated and compared between the conventional and novel orthoradiograms. In subgroup analysis, cases with < 5% and > 5% differences in WBL ratios between two orthoradiograms were classified as consistent and inconsistent groups, respectively. Receiver operating characteristic curve based on the HKA angles of the lower limbs was used to identify the COV causing the inconsistency between the orthoradiograms. RESULTS: Inter- and intra-rater reliabilities of all radiologic measurements were > 0.75. The WBL ratios showed no significant difference between the two orthoradiograms. However, the HKA angle was significantly larger in the inconsistent group than in the consistent group (7.0° ± 1.8° vs. 4.4° ± 2.5°; P < 0.001). The COV of the HKA angle that caused inconsistency in the two orthoradiograms was 4.0° (area under the curve, 0.774). CONCLUSION: The hip-to-calcaneus alignment differed significantly from the hip-to-talus alignment in patients with genu varum deformity. HCR measurement can be a complementary method for planning corrective osteotomy for patients with genu varum deformity. LEVEL OF EVIDENCE: IV.

National pharmacological treatment trends for ankylosing spondylitis in South Korea: A national health insurance database study.

No studies of the current status of treatment options are available for ankylosing spondylitis (AS) patients in South Korea. This study assesses the current status of AS treatment trends using a nationwide database. This study was conducted using a Korean National Health Insurance System (KNHIS) dataset from 2006 to 2016. We randomly extracted 50% of the total number of patients registered as As patients in the KNHIS. The distribution of the number of patients according to age and gender was analyzed each year. The types and combination methods of drugs used during the study period were estimated yearly. Between 2006 and 2016, the number of AS patients increased linearly by an average of 9% annually, 6372 in 2006 to 15188 in 2016. The study found that the use of nonsteroidal anti-inflammatory drugs (NSAIDs) was the most commonly prescribed pharmacological treatment option, followed by disease-modifying anti-rheumatic drugs (DMARDs) and then biologics. Biologics such as tumor necrosis factor alpha (TNF-α) inhibitors increased from 10% to 35% consistently for 10 years. In terms of combination therapy, DMARDs + NSAIDs accounted for almost 90% of treatments in 2006, but decreased by 65% in 2016. The use of biologics and NSAIDs increased from 3% to 28%. Prescriptions for dual therapies and mono therapies largely dominated prescription habits, accounted for up to approximately 80% of treatments. Among 10- to 14-year-old patients, there was no triple therapy, dual and triple therapies decreased gradually for those 60 and older, and the ratio of conservative treatments has increased. This study shows how South Korea reflects changes in AS treatment trends, along with the emergence of TNF-α inhibitors that are effective in treating AS. Research on clinical outcomes for AS treatments will be needed on following these drug changes.

Effects of teriparatide on fusion rates in patients undergoing complex foot and ankle arthrodesis.

BACKGROUND: Here, we determined whether teriparatide treatment would increase fusion rates after foot and ankle arthrodesis by comparing treatment results between patients with high-risk factors for nonunion who received teriparatide against those who did not. METHODS: We retrospectively reviewed 66 consecutive patients who underwent foot and ankle arthrodesis. The inclusion criterion was the presence of at least one of the following risk factors for nonunion after previous foot and ankle arthrodesis: deformity, bone defects, avascular necrosis, and nonunion. Sixteen patients were finally enrolled and divided into 2 groups: 8 patients received teriparatide treatment after fusion surgery (PTH group), and 8 patients did not (control group). RESULTS: The fusion rate was significantly greater in the PTH group than in the control group (100% vs 50%). Four patients in the control group developed nonunion, 3 of whom underwent revision fusion; however, all patients received the teriparatide treatment after revision surgery and subsequently achieved union. No significant differences in demographics, fusion sites, and complication rates were found. CONCLUSION: Though the sample size was small, the current study suggests that teriparatide administration may improve fusion rates in patients with high-risk factors for nonunion after foot and ankle arthrodesis.