Acta Orthopaedica 2011; 82 (6): 685–691 691 Insall J N, Dorr L D, Scott R D, Scott W N. Rationale of the Knee Society clinical rating system. Clin Orthop 1989; [248]: 13-4. Podsiadlo D, Richardson S. The timed “Up & Go”: a test of basic functional mobility for frail elderly persons. J Am Geriatr Soc 1991; 39: 142-8. Julin J, Jamsen E, Puolakka T, Konttinen Y T, Moilanen T. Younger age increases the risk of early prosthesis failure following primary total knee replacement for osteoarthritis. A follow-up study of 32,019 total knee replacements in the Finnish Arthroplasty Register. Acta Orthop 2010; 81: 413-9. Kim Y H, Choi Y, Kwon O R, Kim J S. Functional outcome and range of motion of high-flexion posterior cruciate-retaining and high-flexion poste- rior cruciate-substituting total knee prostheses. A prospective, randomized study. J Bone Joint Surg (Am) 2009; 91: 753-60. Kim Y H, Choi Y, Kim J S. Comparison of a standard and a gender-specific posterior cruciate-substituting high-flexion knee prosthesis: a prospective, randomized, short-term outcome study. J Bone Joint Surg (Am) 2010; 92: 1911-20. Mahomed N N, Liang M H, Cook E F, Daltroy L H, Fortin P R, Fossel A H, Katz J N. The importance of patient expectations in predicting functional outcomes after total joint arthroplasty. J Rheumatol 2002; 29: 1273-9. Manley M T, Stern L S, Gurtowski J. The load carrying and fatigue proper- ties of the stem-cement interface with smooth and porous coated femoral components. J Biomed Mater Res 1985; 19: 563-75. Martucci E, Verni E, Del P G, Stulberg S D. CKS knee prosthesis: biomechan- ics and clinical results in 42 cases. Chir Organi Mov 1996; 81: 247-56. McCalden R W, Macdonald S J, Bourne R B, Marr J T. A randomized con- trolled trial comparing “high-flex” vs “standard” posterior cruciate substi- tuting polyethylene tibial inserts in total knee arthroplasty. J Arthroplasty 2009; 24: 33-8. Mehin R, Burnett R S, Brasher P M. Does the new generation of high-flex knee prostheses improve the post-operative range of movement?: a meta- analysis. J Bone Joint Surg (Br) 2010; 92: 1429-34. Mizner R L, Snyder-Mackler L. Altered loading during walking and sit-to- stand is affected by quadriceps weakness after total knee arthroplasty. J Orthop Res 2005; 23: 1083-90. Noble P C, Conditt M A, Cook K F, Mathis K B. The John Insall Award: Patient expectations affect satisfaction with total knee arthroplasty. Clin Orthop 2006; [452]: 35-43. Pagnano M W, Hanssen A D, Lewallen D G, Stuart M J. Flexion instabil- ity after primary posterior cruciate retaining total knee arthroplasty. Clin Orthop 1998; [356] 39-46. Ploegmakers M J, Ginsel B, Meijerink H J, de Rooy J W, de Waal Malefijt M C, Verdonschot N, Banks S A. Physical examination and in vivo kinematics in two posterior cruciate ligament retaining total knee arthroplasty designs. Knee 2010; 17: 204-9. Pritchett J W. Patients prefer a bicruciate-retaining or the medial pivot total knee prosthesis. J Arthroplasty 2011; 26: 224-8. Rahman W A, Garbuz D S, Masri B A. Randomized controlled trial of radio- graphic and patient-assessed outcomes following fixed versus rotating plat- form total knee arthroplasty. J Arthroplasty 2010; 25: 1201-8. Rand J A, Trousdale R T, Ilstrup D M, Harmsen W S. Factors affecting the durability of primary total knee prostheses. J Bone Joint Surg (Am) 2003; 85: 259-65. Ries M D. Effect of ACL sacrifice, retention, or substitution on kinematics after TKA. Orthopedics 2007; 30: 74-6. Santini A J, Raut V. Ten-year survival analysis of the PFC total knee arthro- plasty–a surgeon’s first 99 replacements. Int Orthop 2008; 32: 459-65. Schwartz A J, la Valle C J, Rosenberg A G, Jacobs J J, Berger R A, Galante J O. Cruciate-retaining TKA using a third-generation system with a four- pegged tibial component: a minimum 10-year followup note. Clin Orthop 2010; (468): 2160-7. Stratford P W, Kennedy D M. Performance measures were necessary to obtain a complete picture of osteoarthritic patients. J Clin Epidemiol 2006; 59: 160-7. Su F C, Lai K A, Hong W H. Rising from chair after total knee arthroplasty. Clin Biomech (Bristol, Avon ) 1998; 13: 176-81. Terwee C B, van der Slikke R M, van Lummel R C, Benink R J, Meijers W G, de Vet H C. Self-reported physical functioning was more influenced by pain than performance-based physical functioning in knee-osteoarthritis patients. J Clin Epidemiol 2006; 59: 724-31. Vessely M B, Whaley A L, Harmsen W S, Schleck C D, Berry D J. The Chi- tranjan Ranawat Award: Long-term survivorship and failure modes of 1000 cemented condylar total knee arthroplasties. Clin Orthop 2006; (452): 28-34. Walsh W R, Svehla M J, Russell J, Saito M, Nakashima T, Gillies R M, Bruce W, Hori R. Cemented fixation with PMMA or Bis-GMA resin hydroxyapa- tite cement: effect of implant surface roughness. Biomaterials 2004; 25: 4929-34. Waslewski G L, Marson B M, Benjamin J B. Early, incapacitating insta- bility of posterior cruciate ligament-retaining total knee arthroplasty. J Arthroplasty 1998; 13: 763-7.