Outcome Predictors for Conservative Patellofemoral Pain Management: A Systematic Review and Meta-Analysis
Patellofemoral pain (PFP) is highly prevalent within both sporting and recreationally active populations. Multiple treatment approaches have been advocated for the management of PFP, attempting to address both intrinsic and extrinsic factors thought to contribute to the development and persistence of pain. A number of predictors of treatment success have been proposed, and evaluated, for directing intervention choice.
Our aim was to systematically review the literature that identifies outcome predictors of specific conservative interventions in the management of PFP, including quality of the current evidence, to guide clinical practice and future studies investigating outcome predictors within this population.
The AMED, CINAHL, EMBASE, MEDLINE and Web of Science databases were searched from inception to April 2013.
Randomized controlled trials (RCTs) and cohort studies.
Study Appraisal and Synthesis Methods
Following initial searching, all potential papers were assessed by two independent reviewers for inclusion using a checklist developed from the inclusion criteria. Cited, and citing, references were also searched in Google Scholar, but unpublished work was not sought. Methodological quality was assessed using a previously designed quality assessment scale. Definitions for levels of evidence were guided by recommendations made by van Tulder et al.
Fifteen low-quality (LQ) cohort studies were included. No RCTs were found. This systematic review identified the evaluation of 205 conservative management outcome predictor variables. Of this large number of variables that have been assessed, 19 (9 %) were found to significantly predict a successful outcome. Where two or more outcome predictors and success determinants were consistent between studies, data were pooled. Within these studies, the low number of participants per output variable, and absence of controls, is likely to compromise the validity of the predictor’s accuracy. Very limited evidence identified higher functional index questionnaire scores (mean 0.82, 95 % confidence interval [CI] 0.18–1.46), greater forefoot valgus (mean 0.67, 95 % CI 0.05–1.28) and greater rearfoot eversion magnitude peak (mean −0.93, 95 % CI −1.84 to −0.01) to significantly predict improved outcomes with orthoses interventions. Shorter symptom duration (p = 0.019), lower frequency of pain (p = 0.012), younger age, faster vastus medialis oblique reflex response time (p = 0.026), negative patella apprehension, absence of chondromalacia patella, tibial tubercle deviation of <14.6 mm and greater total quadriceps cross-sectional area on magnetic resonance imaging (p = 0.01), and reduced eccentric average quadriceps peak torque (p = 0.015) significantly predicted exercise intervention success following multivariate statistical analysis. Limited evidence identified increased Q-angle (mean 0.38, 95 % CI 0.05–0.72) and very limited evidence identified greater usual pain (mean 0.43, 95 % CI 0.01–0.85) to predict taping intervention success.
This systematic review provides a comprehensive summary of current derivation level studies identifying indicators of prediction for conservative PFP management. The overall strength of evidence was low. With appropriate caution, clinicians should consider taping for those with greater usual pain, orthoses for older individuals and exercise for younger individuals, and orthoses intervention for patients with greater forefoot valgus and rearfoot eversion magnitude peak. RCTs with evaluation of outcome prediction as a primary aim are clearly warranted to provide clinicians with robust evidence and facilitate evidence-informed, tailored intervention to this heterogeneous patient population.
KeywordsExercise Intervention Electronic Supplementary Material Table Outcome Predictor Lysholm Score Clinical Prediction Rule
No sources of funding were used to assist in the preparation of this review. Simon Lack, Christian Barton, Bill Vicenzino and Dylan Morrissey have no potential conflicts of interest that are directly relevant to the content of this review.
- 3.D’Hondt NE, Struijs PA, Kerkhoffs GM, et al. Orthotic devices for treating patellofemoral pain syndrome. Cochrane Database Syst Rev. 2002;(2):CD002267.Google Scholar
- 8.Khayambashi K, Mohammadkhani Z, Ghaznavi K, et al. The effects of isolated hip abductor and external rotator muscle strengthening on pain, health status, and hip strength in females with patellofemoral pain: a randomized controlled trial. J Orthop Sports Phys Ther. 2012;42(1):22–9.PubMedCrossRefGoogle Scholar
- 21.Iverson CA, Sutlive TG, Crowell MS, et al. Lumbopelvic manipulation for the treatment of patients with patellofemoral pain syndrome: development of a clinical prediction rule. Including commentary by Powers CM, with authors’ response. J Orthop Sports Phys Ther. 2008;38(6):297–313.PubMedCrossRefGoogle Scholar
- 38.van Tulder M, Furlan A, Bombardier C, et al. Updated method guidelines for systematic reviews in the cochrane collaboration back review group. Spine (Phila Pa 1976). 2003;28(12):1290–9.Google Scholar