SYNOPSIS: Patellofemoral pain syndrome is one of the most common orthopaedic complaints presenting to physical therapists.  Although its etiology is uncertain, the cause is most often considered to be malalignment or lateral tracking of the patella.  Consequently, measurement of patellar alignment has come to be accepted as an integral part of the examination of patellofemoral pain syndrome.  Various measurement techniques exist, both clinical and radiological, and these have been frequently used in the diagnosis and treatment of the condition. As a corollary, the widespread use of such measurements has also lent weight to the theory that patellar malalignment is one of the primary causes of patellofemoral pain syndrome.  However, an analysis of the literature reveals that the vast majority of these measurement procedures lack the appropriate scientific qualities to be considered acceptable measurement tools, including questionable reliability and validity, and an absence of appropriate normative data and a gold standard.  This paper assesses the evidence for the usefulness of the most commonly used measures of patellar alignment and concludes that many of the beliefs of the clinical community with regard to the existence and measurement of patellar malalignment in patellofemoral pain syndrome may be based largely on assumptions and not on evidence.

J Orthop Sports Phys Ther. 2007;37(6):330-341, Epub 16 April 2007. doi:10.2519/jospt.2007.2281

KEY WORDS: anterior knee pain, knee, patella, patellofemoral joint

Study Design: A multicenter, single-masked study of patients with patellofemoral pain syndrome (PFPS) using a repeated-measures design. Objective: To compare 3 different methods of patellar taping for individuals with PFPS. Background: Patellar taping is commonly used as a treatment for PFPS. It is commonly thought that taping works by medially realigning the patella. However, comparisons have been rarely made with other methods of taping which attempt to realign the patella in different directions. Methods and Measures: Seventy-one patients with PFPS (39 men, 32 women; average age ± SD, 34 ± 10 years) from 3 different treatment centers were tested. Each patient performed 4 single step-downs from a standard 8-inch (20.3-cm) platform, initially with the patella untaped and then with the patella taped in a medial, neutral, and lateral direction. Pain was recorded on a standard 11-point numerical pain rating scale. The sequence of taping was randomly allocated and patients were masked to the method used. The methods of taping were compared using repeated-measures generalized linear model analysis. Results: All methods of taping significantly decreased pain when compared to the untaped condition (P<.0001). Neutral- and lateral-glide techniques produced a significantly greater degree of pain relief (P<.0001) than the medial-glide technique. Conclusion: In this study, patellar taping produced an immediate decrease in pain in patients with PFPS, irrespective of how taping was applied. These data raise questions as to the mechanism of action of patellar taping. Furthermore, these results suggest that it is unlikely that taping works by altering patellar position.

Invited Commentary by Sallie Cowan 

J Orthop Sports Phys Ther. 2003;33(8):437-448.

Key Words: knee, lower extremity, patella, tape