In 2016, 16 experts in orthopedic surgery, physical therapy and basic science participated in a workshop to come to a consensus on the definitions of patellofemoral stability and instability, the clinical evaluation of patients with suspected patellar instability, treatment recommendations and future direction of study.
In the consensus document, which is designed through a combination of bullet points and discussion for brevity and clarity, researchers defined patellofemoral stability and instability, laxity and patholaxity. The researchers also reviewed factors that contribute to instability, key questions to ask during history taking and key points for physical examination and imaging.
William R. Post
Overall, the researchers noted that lateral patellar instability is the most common problem warranting surgery. When it comes to surgical treatment, researchers could not recommend isolated lateral retinacular release or lengthening as it is inconsistent and has been shown to have poor outcomes. Patients should undergo medial reconstruction with or without lateral release or lengthening when they have no more than mild trochlear dysplasia, as well as clear evidence of pathologic laxity on history, physical examination and examination under anesthesia, according to the researchers. When pathologic lateral retinacular tightness is present, researchers indicated lateral release or lengthening in addition to medial patellofemoral ligament reconstruction. Although trochleoplasty is not often indicated as it is technically challenging with potentially severe complications, researchers recommended patients undergo deepening trochleoplasty when they present with a J-sign, a boss or supratrochlear spur of 5 cm or greater, and a convex proximal trochlea.
“The consensus statement is an important step toward expressing what we believe to be the state of the art knowledge for treatment of patellofemoral instability,” William R. Post, MD, co-chairman of the workshop, told Healio.com/Orthopedics. “It was important to start with the basics of defining what we precisely mean by patellofemoral stability and instability and then use that understanding to define logical guidelines, not just for treatment, but also for patient evaluation. As with any treatment, accurate diagnosis is a critical step in good treatment and is not always so easy in patients with patellofemoral instability.” – by Casey Tingle
Disclosures: This work was sponsored by grants from the American Orthopaedic Society for Sports Medicine, Patellofemoral Foundation and Ferring Pharmaceutical. Please see the full study for a list of all other authors’ relevant financial disclosures.