title: Evaluation of anterior knee pain in a PS total knee arthroplasty: the role of patella-friendly femoral component and patellar size.
abstract: BACKGROUND
  Total knee arthroplasty gives excellent objective results. Nevertheless, the subjective findings do not match the normal knee perception: Often, it depends on patellar pain onset. In this study, we analyzed clinical and radiological items that can affect resurfaced patellar tracking, and role of a patella-friendly femoral component and patellar size on patellar pain onset.
  
  
  METHODS
  Thirty consecutive patients were implanted using the same-cemented posterior-stabilized TKA associated with patella resurfacing. Fifteen patients were implanted using a classical femoral component, while another 15 patients were implanted using a patella-friendly femoral component. The statistical analysis was set to detect a significant difference (p < 0.05) in clinical and radiological outcomes related to several surgical parameters. Clinical and functional outcomes were recorded using the Knee Society Scoring System (KSS) and patellar pain with the Burnett questionnaire.
  
  
  RESULTS
  Mean follow-up was 25 months. KSS results were excellent in both groups. Group 2 (patella-friendly femoral model) reached a higher percentage of 100 points in the clinical and functional KSS, but there was no statistical difference. Also, no statistical differences for Burnett Questionnaire results were recorded. We had one case of patellar clunk syndrome in the standard femoral component group and one poor result in the second group. Postoperative radiographic measurements evidenced no statistical differences in both groups. In group 1 (classical femoral component), better significant result (p < 0.05) war recorded at clinical evaluation according to the Knee Society Scoring System (KSS) in case of wider patellar component resurfaced.
  
  
  CONCLUSIONS
  The present study reveals no statistically significant difference in the incidence of anterior knee pain between classical and "patella-friendly" femoral components. With the particular type of implant design utilized in this study, when the classical femoral component is used, bigger patellar implant sizes (38 and 41 mm) showed superior clinical outcome.
authors: Unit of Orthopaedics and Traumatology, Hospital San Luigi Gonzaga, University of Turin, Regione Gonzole 10, Orbassano, 10043, Turin, Italy, f_atz@libero.it.
authors: F
authors: F
authors: Atzori
authors: L
authors: L
authors: Sabatini
authors: D
authors: D
authors: Deledda
authors: M
authors: M
authors: Schirò
authors: R
authors: R
authors: Lo Baido
authors: R L
authors: RL
authors: Baido
authors: A
authors: A
authors: Massè
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000601:surgery*; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000209:etiology; D010329:Patella / Q000473:pathology; D057071:Patellofemoral Joint / Q000473:pathology; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D016896:Treatment Outcome