Inline dynamometry provides reliable measurements of quadriceps strength in healthy and ACL-reconstructed individuals and is a valid substitute for isometric electromechanical dynamometry following ACL reconstruction.

BackgroundQuadriceps strength testing is recommended to guide rehabilitation and mitigate the risk of second injury following anterior cruciate ligament (ACL) reconstruction. Hand-held dynamometry is a practical alternative to electromechanical dynamometry but demonstrates insufficient reliability and criterion validity in healthy and ACL-reconstructed participants respectively. The purpose of this study is to investigate the reliability and concurrent validity of inline dynamometry for measuring quadriceps strength. The hypotheses are that intra-class correlation coefficient (ICC) values will be >0.90 for reliability and concurrent validity.MethodsThis was a cross sectional study using a within-participant, repeated measures design. Isometric quadriceps testing was performed at 60° knee flexion in 50 healthy and 52 ACL-reconstructed participants. Interrater reliability, intrarater reliability, and concurrent validity of inline dynamometry was investigated through calculation of ICCs, Bland-Altman analysis, linear regression, standard error of measurement (SEM) and minimal detectable change (MDC).ResultsThe lower bounds of the 95% confidence intervals were >0.90 for all reliability and validity ICCs in healthy and ACL-reconstructed participants, except for intrarater reliability in healthy participants using absolute scores (ICC = 0.936 [95% CI 0.890-0.963]). In ACL-reconstructed participants, Bland-Altman bias was 0.01 Nm/kg for absolute and average scores, limits of agreement were -11.74% to 12.59% for absolute scores, the SEM was 0.13Nm/kg (95% CI 0.10-0.17) and the MDC was 0.36Nm/kg (95% CI 0.28 - 0.47).ConclusionInline dynamometry is a reliable and economical alternative to electromechanical dynamometry for the assessment of quadriceps strength following ACL-reconstruction.Clinical trial registration numberClinicalTrials.gov (NCT05109871)

Immediate and midterm cardiac remodelling following surgical pulmonary valve replacement in adults with repaired tetralogy of fallot: a prospective cardiovascular magnetic resonance and clinical study

Background: Pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot provides symptomatic benefit and right ventricular (RV) volume reduction. However, data on the rate of ventricular structural and functional adaptation are scarce. We aimed to assess immediate and midterm post-PVR changes and predictors of reverse remoeling. Methods: Fifty-seven patients with repaired tetralogy of Fallot (age ≥16 y; mean age, 35.8±10.1 y; 38 male) undergoing PVR were prospectively recruited for cardiovascular magnetic resonance performed before PVR (pPVR), immediately after PVR (median, 6 d), and midterm after PVR (mPVR; median, 3 y). Results: There were immediate and midterm reductions in indexed RV end-diastolic volumes and RV end-systolic volumes (RVESVi) (indexed RV end-diastolic volume pPVR versus immediately after PVR versus mPVR, 156.1±41.9 versus 104.9±28.4 versus 104.2±34.4 mL/m2; RVESVi pPVR versus immediately after PVR versus mPVR, 74.9±26.2 versus 57.4±22.7 versus 50.5±21.7 mL/m2; P<0.01). Normal postoperative diastolic and systolic RV volumes (the primary end point) achieved in 70% of patients were predicted by a preoperative indexed RV end-diastolic volume ≤158 mL/m2 and RVESVi ≤82 mL/m2. RVESVi showed a progressive decrease from baseline to immediate to midterm follow-up, indicating ongoing intrinsic RV functional improvement after PVR. Left ventricular ejection fraction improved (pPVR versus mPVR, 59.4±7.6% versus 61.9±6.8%; P<0.01), and right atrial reverse remodeling occurred (pPVR versus mPVR, 15.2±3.4 versus 13.8±3.6 cm2/m2; P<0.01). Larger preoperative RV outflow tract scar was associated with a smaller improvement in post-PVR RV/left ventricular ejection fraction. RV ejection fraction and peak oxygen uptake predicted mortality (P=0.03) over a median of 9.5 years of follow-up. Conclusions: Significant right heart structural reverse remodeling takes place immediately after PVR, followed by a continuing process of further biological remodeling manifested by further reduction in RVESVi. PVR before RVESVi reaches 82 mL/m2 confers optimal chances of normalization of RV function