title: Flexion and anterior knee pain after high flexion posterior stabilized or cruciate retaining knee replacement.
abstract: BACKGROUND
  Special high-flexion prosthetic designs show a small increase in postoperative flexion compared to standard designs and some papers show increased anterior knee pain with these prosthesis.
  
  
  METHODS
  A prospective double blind randomized controlled trial investigates the difference in flexion and anterior knee pain between standard and high-flexion total knee arthroplasty. In total 47 patients were randomly allocated to a standard cruciate retaining fixed bearing design (CR) in 23 patients and to a high-flexion posterior stabilized mobile bearing design (HF-PS) in 24 patients.
  
  
  RESULTS
  The HF-PS did show a significantly higher passive postoperative flexion; 120.8° (SD 10.3°) vs. 112.0° (SD 9.5°) for the CR group (p = 0.004). The active postoperative flexion, VAS-pain score and Feller score did not show significant differences between both groups. Sub analysis with the HF-PS group showed a higher VAS-pain for the patients achieving ≥130° of flexion; 30.5 (SD 32.2) vs. 12.2 (SD 12.5) (p = 0.16).
  
  
  CONCLUSIONS
  The present study showed a significant higher passive flexion in the high-flexion prosthesis compared to the standard prosthesis. However this difference disappeared when comparing active flexion. No difference in anterior knee pain was found between both groups.
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: van de Groes
authors.forename: Paul
authors.initials: P
authors.lastname: van der Ven
authors.forename: Keetie
authors.initials: K
authors.lastname: Kremers-van de Hei
authors.forename: Sander
authors.initials: S
authors.lastname: Koëter
authors.forename: Nico
authors.initials: N
authors.lastname: Verdonschot
mesh_terms: D000368:Aged; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D018771:Arthralgia / Q000503:physiopathology*; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D020370:Osteoarthritis, Knee / Q000601:surgery; D010149:Postoperative Pain / Q000209:etiology / Q000503:physiopathology*; D011446:Prospective Studies; D011474:Prosthesis Design; D016059:Range of Motion, Articular