title: Patellofemoral osteoarthritis coexistent with tibiofemoral osteoarthritis in a meniscectomy population.
abstract: OBJECTIVE
  To evaluate the frequency of patellofemoral osteoarthritis and its relevance to symptoms and function in a meniscectomy population.
  
  
  METHODS
  317 patients with no cruciate ligament injury were evaluated (mean (SD) age, 54 (11) years). They had undergone meniscal resection 15 to 22 years earlier (follow up rate 70%). Standing tibiofemoral and skyline patellofemoral radiographs were graded according to the OARSI atlas. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to quantify symptoms and function. Controls were 68 unoperated subjects identified from national population records.
  
  
  RESULTS
  Patellofemoral osteoarthritis (isolated or coexisting with tibiofemoral osteoarthritis) was present in 66 of 317 index knees (21%) and 21 of 263 unoperated contralateral knees (8%, p<0.001). In 57/66 (86%) of these index knees, tibiofemoral osteoarthritis was present (mixed osteoarthritis). In a model adjusted for age, sex, and body mass index, the odds ratio for patellofemoral osteoarthritis (alone or in combination with tibiofemoral osteoarthritis) was 2.6 (95% confidence interval, 1.1 to 6.6) after medial meniscectomy and 5.3 (1.9 to 15.0) after lateral meniscectomy, using controls as the reference. Individuals with a mixed knee osteoarthritis pattern had more symptoms, lower function in sports and recreation, and worse knee related quality of life than subjects with isolated tibiofemoral osteoarthritis.
  
  
  CONCLUSIONS
  Mixed patellofemoral and tibiofemoral osteoarthritis is common in a meniscectomy population. Patellofemoral osteoarthritis is a contributing cause of knee symptoms and reduced knee related quality of life and is relevant to the management of knee complaints of this group of patients.
authors.affiliation: Department of Orthopaedics, Lund University Hospital, SE-221 85 Lund, Sweden. martin.englund@med.lu.se
authors.forename: M
authors.initials: M
authors.lastname: Englund
authors.forename: L S
authors.initials: LS
authors.lastname: Lohmander
mesh_terms: D000328:Adult; D000368:Aged; D004812:Epidemiologic Methods; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006305:Health Status Indicators; D006801:Humans; D007718:Knee Injuries / Q000150:complications / Q000534:rehabilitation / Q000601:surgery*; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D010329:Patella / Q000000981:diagnostic imaging; D011379:Prognosis; D011788:Quality of Life; D011859:Radiography; D013177:Sports; D000070600:Tibial Meniscus Injuries; D016896:Treatment Outcome