title: Anterior knee pain following total knee replacement correlates with the OARSI score of the cartilage of the patella.
abstract: BACKGROUND
  Attempts to relate patellar cartilage involvement to anterior knee pain (AKP) have yielded conflicting results. We determined whether the condition of the cartilage of the patella at the time of knee replacement, as assessed by the OARSI score, correlates with postsurgical AKP.
  
  
  METHODS
  We prospectively studied 100 patients undergoing knee arthroplasty. At surgery, we photographed and biopsied the articular surface of the patella, leaving the patella unresurfaced. Following determination of the microscopic grade of the patellar cartilage lesion and the stage by analyzing the intraoperative photographs, we calculated the OARSI score. We interviewed the patients 1 year after knee arthroplasty using the HSS patella score for diagnosis of AKP.
  
  
  RESULTS
  57 of 95 patients examined had AKP. The average OARSI score of painless patients was 13 (6-20) and that of patients with AKP was 15 (6-20) (p = 0.04). Patients with OARSI scores of 13-24 had 50% higher risk of AKP (prevalence ratio = 1.5, 95% CI: 1.0-2.3) than patients with OARSI scores of 0-12.
  
  
  CONCLUSIONS
  The depth and extent of the cartilage lesion of the knee-cap should be considered when deciding between the various options for treatment of the patella during knee replacement.
authors: University of Tartu , Tartu.
authors: Vahur
authors: V
authors: Metsna
authors: Sigrid
authors: S
authors: Vorobjov
authors: Katrin
authors: K
authors: Lepik
authors: Aare
authors: A
authors: Märtson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018771:Arthralgia / Q000209:etiology* / Q000473:pathology; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D001706:Biopsy; D002358:Cartilage, Articular / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000601:surgery*; D010149:Postoperative Pain / Q000209:etiology* / Q000473:pathology; D010329:Patella / Q000473:pathology / Q000601:surgery*; D010781:Photography; D011446:Prospective Studies; D016896:Treatment Outcome