title: Ten- to 13-Year Results of Mobile Bearing Posterior-Stabilized Rotating-Platform Knee Implants, Reported by Nondesigner Surgeon.
abstract: Posterior-stabilized rotating-platform (PSRP) knee was designed with the purpose of improving postoperative flexion and stability. Its long-term performance has limited reports, which could show whether this purpose has been realized without deleterious effect. We report its long-term results at 10-13 years, of a previously studied cohort, evaluated longitudinally.
  
  
  
  A total of 133 consecutive PSRP implants, selected for 118 patients were studied. Twenty-one patients (24 knees) were deceased and 11 patients (12 knees) were lost to follow-up after 10 years. Eighty patients (97 knees) completed clinical evaluation, of whom 78 patients (88 knees) also completed radiological evaluation.
  
  
  
  Mean flexion improved from 106.8° (30°-150°) to 127° (90°-155°). Forty-three percent patients could sit crosslegged, 32.5% could sit on floor, and 3.4% could squat. Mean knee subscore of Knee Society Score improved from 28 (1-59) to 96 (67-100). Mean function subscore improved from 53 (5-81) to 78 (-10 to 100). After 10 years, 5 patients had zero function score because of developing other debilitating medical illnesses. Twenty-one dead patients (24 knees), at their last follow-up (7.7 years), had satisfactory scores. No patient had spinout or revision. Radiologically, alignment was satisfactory and there was no osteolysis. Kaplan-Meier analysis showed 100% implant survival.
  
  
  
  PSRP design, evaluated after 10 years of implantation in selected patients, had 100% survival with good flexion. Addition of post and cam to the original rotating platform design has provided good stability without untoward effects of wear or osteolysis at 10-13 years.
authors: Department of Orthopedics, Lilavati Hospital, Mumbai, India. Electronic address: drmaniar@jointspeciality.com.
authors: Rajesh N
authors: RN
authors: Maniar
authors: Department of Orthopedics, Padmashree D Y Patil Medical College, Mumbai, India.
authors: Tushar
authors: T
authors: Singhi
authors: Laserx Centre, Mumbai, India.
authors: Parul R
authors: PR
authors: Maniar
authors: Department of Ortho, Veer Chandra Singh Garhwali Government Institute of Medical Science and Research, Srinagar, Uttarakhand, India.
authors: Vipan
authors: V
authors: Kumar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D007719:Knee Joint / Q000601:surgery; D007720:Knee Prosthesis / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D066231:Surgeons
keywords: knee arthroplasty; mobile bearing; posterior stabilized; results; rotating platform