Does the one-leg rise test reflect quadriceps strength in individuals following anterior cruciate ligament reconstruction?

OBJECTIVE: To explore if one-leg rise test performance is associated with quadriceps strength following anterior cruciate ligament reconstruction (ACLR). DESIGN: Cross-sectional. PARTICIPANTS: 100 individuals (50 females, 50 males) aged 18-40 years, 9-36 months post-ACLR with ongoing knee symptoms (KOOS4 <80/100). MAIN OUTCOME MEASURES: Number of one-leg rise repetitions (using an adjustable-height plinth) and isometric quadriceps strength using isokinetic dynamometry (60° flexion, normalised to body mass). Multivariable fractional polynomial regression models adjusted for sex explored relationships between one-leg rise performance (repetitions) and quadriceps strength (Nm/kg) for each limb. RESULTS: A non-linear, increasing association between one-leg rise performance and quadriceps strength was observed, with the rate of increase attenuating at higher values of one-leg rise performance. Similar relationships were observed in the ACLR (ß = 0.15, 95%CI 0.10 to 0.20; adjusted r2 = 0.51) and contralateral limb (ß = 0.14, 95%CI 0.08 to 0.19; r2 = 0.42). CONCLUSION: The one-leg rise test can be an indicator of quadriceps strength in individuals after ACLR, enabling clinicians to easily monitor quadriceps strength recovery without specialised equipment. With the relationship between one-leg rise performance and quadriceps strength attenuating with a larger number of one-leg rises achieved, other factors (e.g., motivation, endurance) likely contribute to one-leg rise performance at higher values.

Rheumatic?-A Digital Diagnostic Decision Support Tool for Individuals Suspecting Rheumatic Diseases: A Multicenter Pilot Validation Study.

Introduction: Digital diagnostic decision support tools promise to accelerate diagnosis and increase health care efficiency in rheumatology. Rheumatic? is an online tool developed by specialists in rheumatology and general medicine together with patients and patient organizations. It calculates a risk score for several rheumatic diseases. We ran a pilot study retrospectively testing Rheumatic? for its ability to differentiate symptoms from existing or emerging immune-mediated rheumatic diseases from other rheumatic and musculoskeletal complaints and disorders in patients visiting rheumatology clinics. Materials and Methods: The performance of Rheumatic? was tested using in three university rheumatology centers: (A) patients at Risk for RA (Karolinska Institutet, n = 50 individuals with musculoskeletal complaints and anti-citrullinated protein antibody positivity) (B) patients with early joint swelling [dataset B (Erlangen) n = 52]. (C) Patients with early arthritis where the clinician considered it likely to be of auto-immune origin [dataset C (Leiden) n = 73]. In dataset A we tested whether Rheumatic? could predict the development of arthritis. In dataset B and C we tested whether Rheumatic? could predict the development of an immune-mediated rheumatic diseases. We examined the discriminative power of the total score with the Wilcoxon rank test and the area-under-the-receiver-operating-characteristic curve (AUC-ROC). Next, we calculated the test characteristics for these patients passing the first or second expert-based Rheumatic? scoring threshold. Results: The total test scores differentiated between: (A) Individuals developing arthritis or not, median 245 vs. 163, P < 0.0001, AUC-ROC = 75.3; (B) patients with an immune-mediated arthritic disease or not median 191 vs. 107, P < 0.0001, AUC-ROC = 79.0; but less patients with an immune-mediated arthritic disease or not amongst those where the clinician already considered an immune mediated disease most likely (median 262 vs. 212, P < 0.0001, AUC-ROC = 53.6). Threshold-1 (advising to visit primary care doctor) was highly specific in dataset A and B (0.72, 0.87, and 0.23, respectively) and sensitive (0.67, 0.61, and 0.67). Threshold-2 (advising to visit rheumatologic care) was very specific in all three centers but not very sensitive: specificity of 1.0, 0.96, and 0.91, sensitivity 0.05, 0.07, 0.14 in dataset A, B, and C, respectively. Conclusion: Rheumatic? is a web-based patient-centered multilingual diagnostic tool capable of differentiating immune-mediated rheumatic conditions from other musculoskeletal problems. The current scoring system needs to be further optimized.