title: Clinical Impact of Coexisting Patellofemoral Osteoarthritis in Japanese Patients With Medial Knee Osteoarthritis.
abstract: OBJECTIVE
  To evaluate the clinical impact in knee osteoarthritis (OA) of coexisting patellofemoral (PF) joint OA (PFOA) in Japanese patients with medial tibiofemoral (TF) joint OA (TFOA).
  
  
  METHODS
  Patients with medial knee OA (n = 143) were enrolled. The radiographic severity of the TF and PF joints, anatomic axis angle of the TF joint, patellar alignment, trochlear morphology, patellar height, and passive range of motion (ROM) of the painful knee were evaluated. Additionally, the Japanese Knee Osteoarthritis Measure (JKOM) was used to investigate the association between the presence of PFOA and clinical symptoms.
  
  
  RESULTS
  PFOA was present in 98 of 143 patients (68.5%) with medial knee OA. Quantile regression analysis revealed that coexisting PFOA was associated with the pain-related subcategory of the JKOM. Furthermore, multiple logistic regression analysis showed that coexisting PFOA was associated with higher odds of reporting knee pain on using stairs while ascending (odds ratio [OR] 4.81 [95% confidence interval (95% CI) 1.73, 14.3]) and descending (OR 3.86 [95% CI 1.44, 10.8]). A more varus knee alignment and lower knee flexion ROM, which are features of patients with coexisting PFOA, were associated with knee pain while ascending/descending stairs. However, patellar alignment, trochlear morphology, and patellar height were not significantly associated with knee pain.
  
  
  CONCLUSIONS
  PFOA coexisting with medial knee OA was associated with worse clinical symptoms, particularly while ascending/descending stairs, although patellar alignment did not contribute to reporting knee pain. Further studies that include evaluation of the PF joint are warranted to develop a basis for an optimal intervention based on compartmental involvement.
authors: Kyoto University, Kyoto, Japan and Japan Society for the Promotion of Science, Tokyo, Japan.
authors: Hirotaka
authors: H
authors: Iijima
authors: Kyoto University, Kyoto, Japan.
authors: Naoto
authors: N
authors: Fukutani
authors: Kyoto University, Kyoto, Japan.
authors: Tomoki
authors: T
authors: Aoyama
authors: Kio University, Nara, Japan.
authors: Takahiko
authors: T
authors: Fukumoto
authors: Kio University, Nara, Japan.
authors: Daisuke
authors: D
authors: Uritani
authors: Nozomi Orthopaedic Clinic, Hiroshima, Japan.
authors: Eishi
authors: E
authors: Kaneda
authors: Ota Orthopaedic Clinic, Kyoto, Japan.
authors: Kazuo
authors: K
authors: Ota
authors: Kyoto University, Kyoto, Japan.
authors: Hiroshi
authors: H
authors: Kuroki
authors: Kyoto University, Kyoto, Japan.
authors: Shuichi
authors: S
authors: Matsuda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D001696:Biomechanical Phenomena; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology*; D010147:Pain Measurement; D057071:Patellofemoral Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011379:Prognosis; D011788:Quality of Life; D011859:Radiography; D016059:Range of Motion, Articular; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires