Background Identifying the impact of coexisting patellofemoral and tibiofemoral osteoarthritis (OA) seems to be important, since the knees with structural changes in both compartments are commonly observed and are more likely to be painful and with function impairments.

Objectives To compare the symptoms and physical function in individuals with patellofemoral and tibiofemoral osteoarthritis coexisting and individuals with tibiofemoral osteoarthritis isolated.

Methods It were selected men and women (40-65 years old). They were diagnosed with knee OA according to the ACR (American College of Rheumatology) criteria and classified regarding the level of severity disease using Kellgren and Lawrence (1957). They were divided into two groups: patellofemoral and tibiofemoral osteoarthritis (PFTFOA) and tibiofemoral osteoarthritis (TFOA) isolated. All the participants had to present OA grade 2 in the tibiofemoral compartment, uni or bilaterally, and to be included in the PFTFOA group, they had also to present signs of OA in patellofemoral compartment. Self-reported symptoms and physical function were assessed by the subscores of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Performance-based tests to assess physical functional were used (30s Chair Stand Test, 40m Fast-paced Walk Test and Stair Climb Test).

Results Fifty eight subjects (23 male and 35 female) with mild knee OA were included in this study. The PFTFOA was composed by 30 subjects (12 male, 18 female, mean age 55±7, height 1,66±0,08, weight 79,6±13,5 and BMI 28,9±3,8) and the TFOA was composed by 28 subjects (11 male, 17 female, mean age 53±7, height 1,67±0,11, weight 75,6±14,1 and BMI 27±3,3). The groups were homogeneous for age (P=0.35), height (P=0.59), weight (P=0.15) and BMI (P=0.05). There were no differences between groups for self-reported pain (P=0.22), stiffness (P=0.20), physical function (P=0.71) and total WOMAC score (P=0.57). There were no differences between groups for Performance-based tests using 30s Chair Stand Test (P=0.63), 40m Fast-paced Walk Test (P=0.89) and Stair Climb Test (P=0.15).

Conclusions The findings from the current study showed no significant differences between the groups PFTFOA and PFOA in regard to pain, stiffness and physical function, as evaluated by self-reported and performance-based tests.

References

1. Dobson et al., 2013, OARSI recommended performance-based tests to assess physical function in osteoarthritis of the hip or knee: authors' reply: Osteoarthritis and Cartilage, v. 21, p. 1625-1626.

2. Duncan et al. 2008, How do pain and function vary with compartmental distribution and severity of radiographic knee osteoarthritis?: Rheumatology (Oxford), v. 47, p. 1704-7.

3. Farrokhi et al. 2013, Severity of Coexisting Patellofemoral Disease is Associated with Increased Impairments and Functional Limitations in Patients with Knee Osteoarthritis: Arthritis Care Res (Hoboken), v. 65, p. 544-51.

4. Stefanik et al. 2013, Using magnetic resonance imaging to determine the compartmental prevalence of knee joint structural damage: Osteoarthritis Cartilage, v. 21, p. 695-9.

Acknowledgements The authors would like to acknowledge the supported financially by Higher Education Personnel Training Coordination (Capes) and by Support Foundation to Research of São Paulo State (FAPESP).

Disclosure of Interest None declared