Risk of stroke after unilateral or bilateral TKA (simultaneous and staged without discharge) in 327,438 matched patients using data from the National Health Insurance Claims for South Korea.

PURPOSE: This study aims to investigate the incidence rate and risk factors of stroke in patients treated with bilateral TKA compared with patients with unilateral TKA. METHODS: In this retrospective nationwide cohort study, we compared patients undergoing unilateral TKA or bilateral TKA using data from the Korean National Health Insurance claims database between January 1, 2009 and August 31, 2017 and included patients older than 40 years of age who underwent primary TKA by the index date as documented primary diagnosis and first additional diagnosis without a history of stroke during the preceding 1 year. We used matched Cox regression models to compare the incidence rate and risk factors of newly acquired stroke among patients treated with unilateral TKA or bilateral TKA after propensity score (PS) matching. RESULTS: In the present study, 163,719 patients who received unilateral TKA were matched to 163,719 patients with bilateral TKA based on PS. The risk of stroke during the study period was lower in patients treated with bilateral TKA than in patients with unilateral TKA (adjusted hazard ratio [HR] 0.79). Patients who received bilateral TKA were at decreased risk of stroke when the following variables were present: advanced age (70-79 years, HR 0.76), female sex (HR 0.75), rural area (HR 0.77), small- or medium-sized hospital (HR 0.75), health insurance (HR 0.77), history of hypertension drug use (HR 0.75), congestive heart failure (HR 0.70), connective tissue disease (HR 0.71), diabetes (HR 0.77), and diabetes with complication (HR 0.76). CONCLUSION: The risk of stroke was lower in patients treated with bilateral TKA than in patients with unilateral TKA. Patients treated with bilateral TKA were at decreased risk of stroke when the following variables were present: age (70-79 years), female sex, health insurance, history of hypertension drug use, and comorbidities, such as congestive heart failure, connective tissue disease, and diabetes.

Correction: Rotating hinge knee versus constrained condylar knee in revision total knee arthroplasty: A meta-analysis.

[This corrects the article DOI: 10.1371/journal.pone.0214279.].

Rotating hinge knee versus constrained condylar knee in revision total knee arthroplasty: A meta-analysis.

There is debate in the literature whether rotating hinge knee (RHK) or constrained condylar knee (CCK) prostheses lead to better clinical outcomes and survival rates in patients undergoing revision total knee arthroplasty (RTKA). The purpose of this meta-analysis is to compare the survivorship and clinical outcomes of RHK and CCK prostheses. In this meta-analysis, we reviewed studies that evaluated pain and function scores, range of motion (ROM), complications, and survival rates in patients treated with RHK or CCK with short-term (<5 years) or midterm (5-10 years) follow-up. The survivorship was considered as the time to additional surgical intervention such as removal or revision of the components. A total of 12 studies (one randomized study and 11 non-randomized studies) met the inclusion criteria and were analyzed in detail. The proportion of the knees in which short-term (<5 years) survival rates (RHK, 83/95; CCK, 111/148; odds ratio [OR] 0.52; 95% CI, 0.24-1.11; P = 0.09) and midterm (5-10 years) survival rates (RHK, 104/128; CCK, 196/234; OR 1.05; 95% CI, 0.56-1.97; P = 0.88) were evaluated did not differ significantly between RHK and CCK prostheses. In addition, there were no significant differences in ROM (95% CI: -0.40 to 9.93; P = 0.07) and complication rates (95% CI: 0.66 to 2.49; P = 0.46). In contrast, CCK groups reported significantly better pain score (95% CI: 0.50 to 2.73; P = 0.005) and function score (95% CI: 0.01 to 2.00; P = 0.05) than RHK groups. This meta-analysis revealed that 87.4% of RHK and 75.0% of CCK prostheses survive at short-term (<5 years), while 81.3% of RHK and 83.8% of CCK prostheses survive at midterm (5-10 years). The differences in standardized mean pain and function scores we detected were likely to be imperceptible to patients and almost certainly below the minimum clinically important level, despite a significant difference in both groups. Based on the findings of the current meta-analysis, RHK prostheses continue to be an option in complex RTKA with reasonable midterm survivorship.

Predictive formula of ideal lumbar lordosis and lower lumbar lordosis determined by individual pelvic incidence in asymptomatic elderly population.

PURPOSE: This study aimed to obtain reference values of lumbar lordosis (LL) and lower LL (LLL) from normal asymptomatic groups, determine the relationship between them and pelvic incidence (PI), and establish the predictive formula for ideal LLL in the elderly Korean population. METHODS: Standing plain lateral radiographs of the whole spine, including the pelvis, were analyzed in asymptomatic adult male volunteers without back pain or prior surgery involving the spine or lower extremity. Volunteers with scoliosis, spondylolisthesis, segmental disk space narrowing, and/or compression fractures in the radiographs were excluded. The following parameters were measured: LL, LLL, and pelvic parameters including PI. The values of PI-LL and PI-LLL were calculated, and the formula using stepwise multiple regression analysis was made. A P value of < 0.05 was considered statistically significant. RESULTS: The study participants included 150 volunteers. All were male participants with an average age of 64.1 ± 6.4. The average value of height, weight, and body mass index was 167.0 ± 5.5 cm, 67.3 ± 9.8 kg, and 24.1 ± 3.1 kg/m2, respectively. The average LL was - 57.5° ± 9.0°, LLL was - 41.7° ± 7.0°, and PI was 48.6° ± 8.6°. The formula was established as follows: PI-LL = 0.38 × PI - 27.61 (R2 = 0.172), PI-LLL = 0.77 × PI - 28.69 (R2 = 0.516), ideal LL = 0.62 × PI + 27.61 (R2 = 0.348), and ideal LLL = 0.225 × PI + 28.63 (R2 = 0.083). CONCLUSIONS: The ideal values of PI-LL and PI-LLL were inconsistent, and they have a positive correlation with PI in asymptomatic elderly population. Our data would be helpful as a normal reference value of ideal LL and LLL according to PI. These slides can be retrieved under Electronic Supplementary Material.

Midterm and Long-term Results of Medial Versus Lateral Meniscal Allograft Transplantation: A Meta-analysis.

BACKGROUND: It is unclear whether lateral meniscal allograft transplantation (MAT) procedures lead to better clinical outcomes than medial MAT. HYPOTHESIS: The survival rates are similar between medial and lateral MAT, but the clinical outcomes of lateral MAT are better than those of medial MAT at final follow-up. STUDY DESIGN: Meta-analysis. METHODS: In this meta-analysis, we reviewed studies that assessed survival rates in patients who underwent medial or lateral MAT with more than 5 years of follow-up and that used assessments such as pain and Lysholm scores to compare postoperative scores on knee outcome scales. The survival time was considered as the time to conversion to knee arthroplasty and/or subtotal resection of the allograft. RESULTS: A total of 9 studies (including 287 knees undergoing surgery using medial MAT and 407 with lateral MAT) met the inclusion criteria and were analyzed in detail. The proportion of knees in which midterm (5-10 years) survival rates (medial, 97/113; lateral, 108/121; odds ratio [OR] 0.71; 95% CI, 0.31-1.64; P = .42) and long-term (>10 years) survival rates (medial, 303/576; lateral, 456/805; OR 0.78; 95% CI, 0.52-1.17; P = .22) were evaluated did not differ significantly between medial and lateral MAT. In addition, both groups had substantial proportions of knees exhibiting midterm survivorship (85.8% for medial MAT and 89.2% for lateral MAT) but much lower proportions of knees exhibiting long-term survivorship (52.6% for medial MAT and 56.6% for lateral MAT). In contrast, overall pain score (medial, 65.6 points; lateral, 71.3 points; 95% CI, -3.95 to -0.87; P = .002) and Lysholm score (medial, 67.5 points; lateral, 72.0 points; 95% CI, -10.17 to -3.94; P < .00001) were significantly higher for lateral MAT compared with medial MAT. CONCLUSION: Meta-analysis indicated that 85.8% of medial and 89.2% of lateral meniscal allograft transplants survive at midterm (5-10 years) while 52.6% of medial and 56.6% of lateral meniscal allograft transplants survive long term (>10 years). Patients undergoing lateral meniscal allograft transplantation demonstrated greater pain relief and functional improvement than patients undergoing medial meniscal allograft transplantations.