The quadriceps or Q-angle is an index of the vector for the combined pull of the extensor mechanisms and the patellar tendon. It is used as an indicator for patellofemoral joint dysfunction. The purpose of this article is to systematically review and appraise the literature to determine the reliability and validity of this test. An electronic database search was performed accessing AMED, British Nursing Index, CINAHL, the Cochrane database, EMBASE, ovid Medline, Physiotherapy Evidence Database (PEDro), PsycINFO, Pubmed and Zetoc to April 2008. All English language, human subject, clinical trials, assessing the inter- or intra-tester reliability, or the criterion validity, were included. The Critical Appraisal Skills Programme appraisal tool was used to establish the methodological quality of each study. Ten articles including 569 control and 179 patellofemoral disorder knees were reviewed. The findings suggest that there is considerable disagreement on the reliability and validity of the clinical Q-angle measurement. This may be due to a lack of standardisation in the measurement procedure. Further study is advocated to re-evaluate this topic using well-designed, and sufficiently large observational studies of specific patellofemoral dysfunction populations.

Purpose: Define whether distal vastus medialis (VM) muscle strengthening improves functional outcomes compared to general quadriceps muscles strengthening following first-time patellar dislocation (FTPD).Methods: Fifty patients post-FTPD were randomised to either a general quadriceps exercise or rehabilitation programme (n=25) or to a specific-VM exercise and rehabilitation regime (n=25).Primary outcome was the Lysholm Knee Score, secondary outcomes included the Tegner Level of Activity Scale, the Norwich Patellar Instability (NPI) Score, and isometric knee extensions strength at various knee flexion ranges of motion. Outcomes were assessed at baseline, six weeks, six months and 12 months.Results: There were statistically significant differences in functional outcome and activity levels through the Lysholm Knee Score and Tegner Level of Activity Scale at 12 months in the general quadriceps exercise group compared to the VM group (p=0.05; 95% CI: -14.0 to 0.0/p=0.04; 95% CI: -3.0 to 0.0). This did not reach a clinically important difference. There was no statistically significant difference between the groups for the NPI Score and isometric strength at any followup interval. The trial experienced substantial participant attrition (52% at 12 months). Conclusions:Whilst there was a statistical difference in Lysholm Knee Score and Tegner Level of Activity Score between general quadriceps and VM exercise groups at 12 months, this may not have necessarily been clinically important. This trial highlights that the recruitment and retention of participants from this population is a challenge and should be considered during the design of future trials in this population. Dislocation -Smith et al (2015) 3 Level of evidence: Therapeutic study, Level I Keywords: Quadriceps; vastus medialis oblique; exercise; patellar dislocation; trial VM versus General Quadriceps following Patellar Dislocation -Smith et al (2015) 4 VM versus General Quadriceps following Patellar IntroductionPatellar dislocation is a disabling musculoskeletal disorder which predominantly affects younger people who are engaged in multi-directional physically active pursuits [1]. The estimated incidence of patellar dislocation is between 7 [2] to 77 per 100,000 people per year [3], with a marginally greater incidence in females [2,4]. The term first-time patellar dislocation (FTPD) represents the first episode that the patella disengages completely from the femoral trochlear. It is sometimes termed primary patellar dislocation [5].Conservative (non-operative) treatment is the treatment of choice for FTPD. Quadriceps strengthening exercises are considered one of the principal management for people following FTPD [6,7]. A United Kingdom (UK) survey of physiotherapy practice has shown that quadriceps strengthening and specific-vastus medialis obliquus (VMO) or distal vastus medialis (VM) muscle strengthening or recruitment exercises were two of the most frequently used interventions for this population [1]. However, there remains controversy rega...

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Purpose: This paper assessed the validity, internal consistency, responsiveness and floor-ceiling effects of the Norwich Patellar Instability (NPI) Score for a cohort of conservatively managed people following first-time patellar dislocation (FTPD).Methods: Fifty patients were recruited, providing 130 completed datasets over 12 months. The NPI Score, Lysholm Knee Score, Tegner Level of Activity Score and isometric knee extension strength were assessed at baseline, six weeks, six and 12 months post-injury. Conclusions:The NPI Score is a valid tool to assess patellar instability symptoms in people conservatively managed following FTPD.

The biomedical field offers many learning tasks that share unique challenges: large amounts of unpaired data, and a high cost to generate labels. In this work, we develop a method to address these issues with semi-supervised learning in regression tasks (e.g., translation from source to target). Our model uses adversarial signals to learn from unpaired datapoints, and imposes a cycle-loss reconstruction error penalty to regularize mappings in either direction against one another. We first evaluate our method on synthetic experiments, demonstrating two primary advantages of the system: 1) distribution matching via the adversarial loss and 2) regularization towards invertible mappings via the cycle loss. We then show a regularization effect and improved performance when paired data is supplemented by additional unpaired data on two real biomedical regression tasks: estimating the physiological effect of medical treatments, and extrapolating gene expression (transcriptomics) signals. Our proposed technique is a promising initial step towards more robust use of adversarial signals in semi-supervised regression, and could be useful for other tasks (e.g., causal inference or modality translation) in the biomedical field.