Kinetic Analysis: A Sensitive Outcome Objective Measurement Method in Evaluating Lateral Patellar Instability

There are many diagnostic clinical tests (e.g., apprehension patellar test or the moving patellar apprehension test), outcome measures (general health and knee scales [IKDC form, Kujala scale, Fulkerson scale, Lysholm knee scoring scale, Tegner activity level scale, short form-36]), and instrumented measurements of patellar mobility (static stability), to assess lateral patellar instability.7,10,15,16 However, according to Smith and colleagues,15 the sensitivity/specificity – reliability/validity of such tests and outcome tools remain unclear for this patient population. These authors conclude that further work is needed to assess the appropriateness of these tests and outcomes.15Moreover, there are many surgical techniques to treat patients with chronic lateral patellar instability, all of them based on level of evidence IV or V.4 This is due, in part, to the lackof prospective randomized trials, and also to the lack of an objective, suitable, reliable, valid, and reproducible noninvasive in vivo method to evaluatelateral patellar instability in the clinical setting. This makes it difficult to compare different surgical treatments in order to find the best surgical technique to treat patients with chronic lateral patellar instability.