A cadaveric model to evaluate the effect of unloading the medial quadriceps on patellar tracking and patellofemoral joint pressure and stability

Background Vastus Medialis Muscles (VMM) damage has been widely identified following patellar dislocation. Rehabilitation programmes have been suggested to strengthen the VMM and reduce clinical symptoms of pain and instability. This controlled laboratory study investigated the hypothesis that reduced Vastus Medialis Obliquus (VMO) and Vastus Medialis Longus (VML) muscle tension would alter patellar tracking, stability and PFJ contact pressures. Methods Nine fresh-frozen dissected cadaveric knees were mounted in a rig with the quadriceps and iliotibial band loaded to 205 N. An optical tracking system measured joint kinematics and pressure sensitive film between the patella and trochlea measured PFJ contact pressures. Measurements were repeated for three conditions: 1. With all quadriceps heads and iliotibial band (ITB) loaded; 2. as 1, but with the VMO muscle unloaded and 3. as 1, but with the VMO and VML unloaded. Measurements were also repeated for the three conditions with a 10 N lateral displacement force applied to the patella. Results Reduction of VMM tension resulted in significant increases in lateral patellar tilt (2.8°) and translation (4 mm), with elevated lateral and reduced medial joint contact pressures from 0.48 to 0.14 MPa, and reduced patellar stability (all p < 0.05). Conclusions These findings provide basic scientific rationale to support the role of quadriceps strengthening to resist patellar lateral maltracking and rebalance the articular contact pressure away from the lateral facet in patients with normal patellofemoral joint anatomy

What parathyroid hormone levels should we aim for in children with stage 5 chronic kidney disease; what is the evidence?

The bone disease that occurs as a result of chronic kidney disease (CKD) is not only debilitating but also linked to poor growth and cardiovascular disease. It is suspected that abnormal bone turnover is the main culprit for these poor outcomes. Plasma parathyroid hormone (PTH) levels are used as a surrogate marker of bone turnover, and there is a small number of studies in children that have attempted to identify the range of PTH levels that correlates with normal bone histology. It is clear that high PTH levels are associated with high bone turnover, although the range is wide. However, the ability of PTH levels to distinguish between low and normal bone turnover is less clear. This is an important issue, because current guidelines for calcium and phosphate management are based upon there being an “optimum” range for PTH. This editorial takes a critical look at the evidence upon which these recommendations are based

Could peak proteinuria determine whether patient with dengue fever develop dengue hemorrhagic/dengue shock syndrome? - A prospective cohort study

BACKGROUND: Worldwide there is a need to develop simple effective predictors that can distinguish whether a patient will progress from dengue fever (DF) to life threatening dengue hemorrhagic (DHF) or dengue shock syndrome (DSS). We explored whether proteinuria could be used as such a marker. METHODS: We included patients admitted to hospital with suspected dengue fever. Starting at enrollment until discharge, each patient's daily spot urine protein creatinine ratio (UPCR) was measured. We classified those with confirmed dengue infection as DF or DHF (including DSS) based on WHO criteria. Peak and day of onset of proteinuria was compared between both groups. RESULTS: Compared to those with DF, patients with DHF had significantly higher median peak proteinuria levels (0.56 versus 0.08 g/day; p < 0.001). For patients with DHF, the median day of onset of proteinuria was at 6 days of defervescence, with a range of -2 to +3 days after defervescence. There were three patients with DF who did not have proteinuria during their illness; the five remaining patients with DF had a median day of onset of proteinuria of was at 6 days of defervescence with a range of 0 to +28 days. CONCLUSIONS: Peak UPCR could potentially predict DHF in patients with dengue requiring close monitoring and treatment