Automatic determination of patellofemoral kinematic parameters through X-ray image processing

Examination of plain Merchant-view X-rays of the patellofemoral joint is often used to diagnose patellofemoral joint malalignment and to qualify the pathology. As digital image processing becomes more widespread, an image processing algorithm is being developed for medical personnel to easily display, manipulate and analyze digitized plain Merchant-view X-ray films on personal computers. The method provides measurement of the kinematic parameters: sulcus angle (SA), patellofemoral congruence angle (PFC), lateral patellar angle (LPA), patellar rotation angle (PR), and lateral patellar displacement (LPD). Smooth edges of the patella and the femur are obtained by using image enhancement, edge detection and morphological thinning techniques based on the thresholds chosen manually for boundary detection. Six landmarks for determining the kinematic parameters are marked automatically on the edges of patella and femur. Parameter measurements for twelve X-ray films of six patients are calculated for analysis and comparison with hand calculated parameters. The goal is develop an algorithm that can evaluate the geometry of the patellofemoral joint, and is cost effective.

Assessment of quadriceps muscle performance by hand-held, isometric, and isokinetic dynamometry in patients with knee dysfunction

One component of patient evaluation is muscle performance assessment. The purpose of this study was: 1) to determine the difference and correlation between hand-held, isometric, and isokinetic dynamometry test results in patients with knee dysfunction and 2) to determine the effect of pain during such testing. Bilateral quadriceps strength in 23 subjects with unilateral knee dysfunction was tested using concentric and eccentric isokinetic dynamometry at 60 degrees/sec, isometric dynamometry, and hand-held dynamometry, both at 60 degrees of knee flexion. Pain ratings were obtained before, during, and after each test. Statistical analysis revealed a significant difference between involved and uninvolved limbs for eccentric isokinetic dynamometry (p = 0.002) and hand-held dynamometry (p = 0.005); no difference was found between limbs for the concentric isokinetic and isometric dynamometry (p > 0.05). Mean percent deficits in quadriceps strength ranged from 11 to 18%, with no significant difference found between testing modes. Pearson product moment correlations ranged from 0.34 to 0.76 when comparing testing modes. No significant difference existed in pain scores before, during, and after each mode of testing. It was concluded that large variation existed between different testing modes, which results in different conclusions regarding the strength of the quadriceps in patients with knee dysfunction.

Lack of variation in the nucleotide sequence corresponding to the transmembrane domain of the beta-amyloid precursor protein in Alzheimer's disease

The nucleotide sequence corresponding to the APP transmembrane domain and flanking regions of charged amino acids was determined for 91 patients with histologically confirmed Alzheimer's disease, 9 patients with dementias of other etiologies, and 14 controls who had no identifiable brain disease. Twenty-eight of the AD patients had a first-degree relative with dementia. No mutations were detected among the 100 demented patients. However, one of the 14 controls exhibited a change in the 3' base of codon 716 which would not be expected to result in an amino acid substitution at this position.

Effects of patella taping on patella position and perceived pain

Anterior knee pain syndrome (AKPS) represents a significant challenge for the sports medicine clinician. One proposed etiological factor for AKPS is poor vastus medialis obliquus (VMO) control, resulting in lateral glide of the patella. Patella taping has been advocated to increase VMO control. The purpose of this study was to determine the effects of patella taping on patella position and perceived pain. Twelve subjects (age = 29 +/- 9 yr; weight = 70.9 kg +/- 17.8; height = 174.0 cm +/- 8.1) with AKPS currently using patella taping procedures with a decrease in their symptoms participated. Each subject had Merchant's view x-rays taken pre- and post-taping while performing an isometric quadriceps contraction to determine patella rotation and patella congruency angles. Subjects also completed a visual analog pain scale after performing a 0.2 m (8") step-down both pre- and post-taping. Paired t-tests revealed no significant change in patellofemoral congruency (P = 0.98) and patella rotation angles (P = 0.80). Significant reduction (50%) in subject pain level was revealed by the visual analog scale (t(15) = 4.99; P < 0.0005). Results demonstrate that patella taping significantly reduced the perceived pain levels during a 0.2-m step-down; however, this reduction in pain was not associated with patella position changes.

Telephone advice nurse: identifying critically-ill patients

Patients who are admitted to Intensive Care Units (ICUs) have usually been critically ill at home first. The telephone advice nurse may be the first person they contact for help when they get sick. This nurse has to distinguish rapidly between critical and non-critical patients. You might find this role a challenging career option.