Outcome of kinematic alignment using patient-specific instrumentation versus mechanical alignment in TKA: a meta-analysis and subgroup analysis of randomised trials.

INTRODUCTION: Kinematic alignment (KA) in total knee arthroplasty (TKA) matches component position to the pre-arthritic anatomy of an individual patient, with the aim of improving functional outcomes. Recent randomised controlled trials (RCTs) comparing KA to traditional neutral mechanical alignment (MA) have been mixed. This collaborative study combined raw data from RCTs, aiming to compare functional outcomes between KA using patient-specific instrumentation (PSI) and MA, and whether any patient subgroups may benefit more from KA technique. MATERIALS AND METHODS: A literature search in PubMed, EMBASE and Cochrane databases identified four randomised controlled trials comparing patients undergoing TKA using PSI-KA and MA. Unpublished data including Western Ontario McMaster Universities Arthritis Index (WOMAC) and Knee Society Score (KSS) were obtained from study authors. Meta-analysis compared MA to KA change (post-op minus pre-op) scores. Subgroup-analysis on KA patients looked for subgroups more likely to benefit from KA and the impact of PSI accuracy. RESULTS: Meta-analyses of change scores in 229 KA patients versus 229 MA patients were no different from WOMAC (mean difference 3.4; 95% confidence interval - 0.5 to 7.3), KSS function (1.3, - 3.9 to 6.4) or KSS combined (7.2, - 0.8 to 15.2). A small advantage was seen for KSS pain in the KA group (3.6, 95% CI 0.2-7.1). Subgroup-analysis showed no difference between varus, valgus and neutral pre-operative alignment groups, and those who did and did not achieve KA plans. Pain-free patients at 1-year were more likely to achieve KA plans. CONCLUSION: Patient-reported outcome scores following TKA using PSI-KA are similar to MA. No identifiable subgroups benefited more from KA, and long-term results remain unknown. Inaccuracy of the PSI system used in KA patients could potentially affect outcome.

Systematic review and meta-analysis of use of serum C-reactive protein levels to predict anastomotic leak after colorectal surgery.

BACKGROUND: Several recent studies have investigated the role of C-reactive protein (CRP) as an early marker of anastomotic leakage following colorectal surgery. The aim of this systematic review and meta-analysis was to evaluate the predictive value of CRP in this setting. METHODS: A systematic literature search was performed using MEDLINE, Embase and PubMed to identify studies evaluating the diagnostic accuracy of postoperative CRP for anastomotic leakage following colorectal surgery. A meta-analysis was carried out using a random-effects model and pooled predictive parameters were determined along with a CRP cut-off value at each postoperative day (POD). RESULTS: Seven studies, with a total of 2483 patients, were included. The pooled prevalence of leakage was 9·6 per cent and the median day on which leakage was diagnosed ranged from POD 6 to 9. The serum CRP level on POD 3, 4 and 5 had comparable diagnostic accuracy for the development of an anastomotic leak with a pooled area under the curve of 0·81 (95 per cent confidence interval 0·75 to 0·86), 0·80 (0·74 to 0·86) and 0·80 (0·73 to 0·87) respectively. The derived CRP cut-off values were 172 mg/l on POD 3, 124 mg/l on POD 4 and 144 mg/l on POD 5; these corresponded to a negative predictive value of 97 per cent and a negative likelihood ratio of 0·26-0·33. All three time points had a low positive predictive value for leakage, ranging between 21 and 23 per cent. CONCLUSION: CRP is a useful negative predictive test for the development of anastomotic leakage following colorectal surgery.

Variability of memory B cell markers in a cohort of common variable immune deficiency patients over 6 months.

Common Variable Immunodeficiency Disorder (CVID) is a complex disorder that predisposes patients to recurrent and severe infections. Immunophenotypic classification schemes were developed to categorize patients with CVID into phenotypic and prognostic groups based on different memory B cell subsets. Whether the B cell subset analysis is stable over time has not been investigated. B cell phenotyping in patients with CVID (n = 15) and sex- and age-matched controls (n = 26) were carried out according to the three B cell classifications. Patients with CVID were evaluated monthly over 6 months. Controls were assessed once during the study. We scored how often each patient was assigned to the same group within each classification. The Freiburg classification assigned patients to the same group at a rate of 73% and the Paris classification at 88%. The EUROclass classification of smB- versus smB+ was at 90%. The two subclassifications [(smB-21low or smB-21norm) and transitional B] were at 87% and 97%, respectively. The level of naïve B cells measured in all patients with CVID during the 6-month evaluation was the most stable B cell subset. We conclude that all classifications systems show considerable variability, but the EUROclass classification was the most reliable scheme for our 15 CVID and 26 healthy cohorts. Our results indicate that phenotypic classifications within CVID will be difficult while there is variability of commonly used assays.

B-type natriuretic peptide and left ventricular dysfunction on exercise echocardiography in patients with chronic aortic regurgitation.

OBJECTIVE: To determine whether plasma levels of B-type natriuretic peptide (BNP) predict left ventricular (LV) dysfunction on exercise echocardiography in patients with moderate to severe aortic regurgitation (AR). DESIGN: Case-control study. SETTING: Outpatient cardiology departments. PATIENTS: 39 asymptomatic or mildly symptomatic patients with chronic moderate to severe AR and a normal LV ejection fraction (>50%), and 10 normal controls. MAIN OUTCOME MEASURES: Plasma level of BNP and echocardiographic measures of LV function at rest and immediately after treadmill exercise. RESULTS: LV end systolic volume index (LVESVI) was significantly increased in AR patients with normal BNP (0.05 for all). However, there were modest but statistically significant associations between the plasma level of BNP and severity of AR indicated by a greater AR:LV outflow tract width ratio (r = 0.37, p = 0.02) and lower diastolic blood pressure (r = -0.44, p = 0.004). Increased BNP was also associated with a greater LVESVI (r = 0.33, p = 0.04) and lower LV longitudinal strain rate (r = -0.037, 0.02) on echocardiography after exercise. CONCLUSIONS: In moderate to severe AR compensatory LV remodelling can occur with no increase in plasma BNP. Increased BNP is associated with more severe regurgitation and changes consistent with early LV dysfunction on exercise echocardiography.