By P.K. Daniel
A new treatment algorithm for patients with patellofemoral pain syndrome (PFPS), designed by researchers at Nationwide Children’s Hospital in Columbus, OH, was associated with clinically significant improvement in pain and disability in a recent pilot study.
The investigators enrolled 30 patients with PFPS, who were assigned to subgroups based on a sequence of tests for fear avoidance, flexibility, and functional malalignment. Patients whose test results did not qualify them for one of those three subgroups were assigned to a fourth subgroup focused on progressive strengthening. All patients received physical therapy two times per week for six weeks, progressing from one subgroup to the next, in the order listed above, based on the achievement of subgroup-specific goals.
“The treatment algorithm is goal-based rather than intervention-based,” said lead study author Mitchell Selhorst, DPT, OCS. “For each subgroup, the goal is to address a primary impairment found to be important for patients with patellofemoral pain.”
After six weeks, the researchers found clinically significant improvements in AKPS (anterior knee pain scale) and GRoC (Global Rating of Change) scores for the 21 patients who were available for analysis. Eighty percent of patients progressed through all four subgroups by the end of the study, Selhorst said. The findings were published in the April issue of the International Journal of Sports Physical Therapy.
Investigators selected adolescent patients for their pilot study because individuals typically develop patellofemoral pain between ages 12 and 17 years. However, Selhorst said their algorithm may also be applicable in older individuals who present with quadriceps and hip musculature weakness, altered lower extremity kinematics, decreased flexibility, and psychosocial stressors.
Jennifer E. Earl-Boehm, PhD, ATC, an associate professor in the College of Health
Sciences at the University of Wisconsin in Milwaukee, said of the approach: “The flexibility, strengthening, and neuromuscular approaches to treatment are all based on strong evidence from the literature. The psychological/educational intervention is a novel approach that has not yet been tested in the literature. … This has the potential to be impactful in their future RCT [randomized controlled trial].”
Although fear-avoidance interventions had not previously been studied in patients with PFPS, a 2009 study found fear-avoidance beliefs were strong predictors of pain and function after standard physical therapy in adults with PFP.
“We ordered the approach because there is research to show that, if psychosocial components are not addressed, the patient is less likely to improve no matter the physical intervention prescribed,” Selhorst said. “Patients with impaired flexibility are more likely to have poor body mechanics, as well as increased joint compression. Finally, before high-level strengthening is begun, we felt having proper mechanics was vital to avoid aggravation or reinjury to the patellofemoral joint.”
Selhorst also said the algorithm can be individualized to fit the patient’s and the treating clinician’s preferences with regard to specific interventions.
“The clinician is free to apply any intervention that will help them achieve the subgroup’s goal,” he said. “For example, if a patient is placed into the flexibility subgroup, the patient can be treated with static stretching, dynamic stretching, and even manual therapy. The key is to assess the patient’s response towards the goal of the subgroup.”
Investigators will make minor changes to the protocol and outcome measures for the larger RCT, for which recruitment is expected to begin in June. The researchers found that some patients (the 20% who did not complete the progression) had difficulty meeting the weight-bearing dorsiflexion range of motion goal required to advance from the flexibility subgroup to the functional malalignment subgroup. As a result, the researchers lowered the flexibility goal for the RCT protocol, but it is still within the 95% confidence interval found in previous research, Selhorst said.
Selhorst M, Rice W, Degenhart T, et al. Evaluation of a treatment algorithm for patients with patellofemoral pain syndrome: A pilot study. Int J Sports Phys Ther 2015;10(2):178-188.
Piva SR, Fitzgerald GK, Wisniewski S, Delitto A. Predictors of pain and function outcome after rehabilitation in
patients with patellofemoral pain syndrome. J Rehabil Med 2009;41(8): 604-612.