Radiographic clues to the unstable knee: are findings of trochlear dysplasia on lateral knee radiographs reliable and predictive of patellar dislocation?

BACKGROUND: Trochlear dysplasia (TD) is a key predisposing risk factor for patellar instability (PI) and lateral patellar dislocation (LPD) injuries. It is useful to understand the reliability of radiographic findings of TD and the accuracy of knee radiographs in diagnosing patients with recent LPD. PURPOSE: The purposes of our study are to evaluate the inter-rater reliability of specific radiographic signs of PI and staging of TD between radiologists and orthopedic surgeons, and to identify which findings are associated with recent LPD. METHODS: This retrospective study comprised 336 patients aged 8 to 18 who obtained knee radiographs over a 3-year period. Two radiologists and two orthopedic surgeons, blinded to patient history, examined radiographs for indicators of PI. Using data from 19 confirmed LPD cases and 317 controls, inter-observer agreement (kappa, Pearson's correlation coefficient) was assessed, as was the odds ratio for likelihood of LPD. RESULTS: There was nearly perfect agreement between radiologists for patella-tendon ratios (Pearson's correlation coefficient 0.8377, P < 0.0001) and discrimination between normal knees and high-grade TD (kappa 0.9213, P < 0.0001). There is fair agreement between radiologists and surgeons distinguishing between normal knees and high-grade TD (kappa 0.5843, P < 0.0001). Lateral knee radiographs interpreted as high-grade TD were highly predictive of LPD (odds ratio 7.58-54.8) among all readers. CONCLUSIONS: There is high agreement between radiologists when evaluating lateral knee radiographs for signs of TD, validating the results of prior literature. Radiographic findings TD, patella alta, and effusion are variable predictors of recent LPD, greatest among patients with TD.

ACR Appropriateness Criteria(®) on suspected lower extremity deep vein thrombosis.

Lower extremity deep vein thrombosis (DVT) is a common clinical concern, with an incidence that increases with advanced age. DVT typically begins below the knee but may extend proximally and result in pulmonary embolism. Pulmonary embolism can occur in 50% to 60% of patients with untreated DVT and can be fatal. Although clinical examination and plasma d-dimer blood evaluation can often predict the presence of DVT, imaging remains critical for the diagnostic confirmation and treatment planning of DVT. Patients with above-the-knee or proximal DVT have a high risk for pulmonary embolism and are recommended to receive anticoagulation therapy. On the other hand, patients with below-the-knee or distal DVT rarely experience pulmonary embolism, and anticoagulation therapy in these patients remains controversial. However, one sixth of patients with distal DVT may experience extension of their thrombus above the knee and therefore are recommended to undergo serial imaging assessment at 1 week to exclude proximal DVT extension if anticoagulation therapy is not initiated. Ultrasound is the preferred imaging method for evaluation of patients with newly suspected lower extremity DVT. Magnetic resonance and CT venography can be especially helpful for the evaluation of suspected DVT in the pelvis and thigh. Contrast x-ray venography, the historic gold standard for DVT assessment, is now less commonly performed and primarily reserved for patients with more complex presentations such as those with suspected recurrent acute DVT.

Instituting preventive health programs at a level I aid station in a combat environment.

Preventive medical services have become standard at fixed military medical facilities worldwide. Unfortunately, offering these same programs can prove difficult during military deployments, because of mission demands and at times limited medical resources. We present successful implementation of physical therapy and smoking cessation programs at a level I aid station supporting soldiers during Operation Iraqi Freedom.