title: Deep-dished highly congruent tibial insert in CR-TKA does not prevent patellar tendon angle increase and patellar anterior translation.
abstract: OBJECTIVE
  Starting from the hypothesis that a deep-dished highly congruent tibial insert in cruciate-retaining total knee arthroplasty would prevent the increase in patellar tendon angle and anterior patellar translation by reducing the paradoxical anterior femoral translation, the main purpose of the present study was to investigate the effect of this prosthesis design, and secondary to assess the clinical outcomes at 6-month follow-up.
  
  
  METHODS
  Twenty patients treated with cruciate-retaining total knee arthroplasty with navigation technique were enrolled and prospectively followed up at 6 months. The median value of age was 71 years (57-83). Before and after surgery, the following parameters were calculated: patellar tendon angle, anterior-posterior and medio-lateral patellar translation, patellar height and range of motion. All patients were assessed with the SF-36 Physical Functioning and the Knee injury and Osteoarthritis Outcome Score ADL scores.
  
  
  RESULTS
  Patellar tendon angle and anterior patellar translation significantly increased in post-operative conditions (p < 0.0001); a statistically significant medial patellar translation was found (p < 0.0001), while patellar height did not show any difference between pre- and post-operative conditions (n.s). A significant correlation was found between patellar tendon angle and anterior patellar translation and the clinical scores (p < 0.0417). There was a significant post-operative decrease (p < 0.0033) in the range of motion.
  
  
  CONCLUSIONS
  The present study failed to demonstrate that deep-dished highly congruent tibial insert prevents the anterior translation of the patella in cruciate-retaining total knee arthroplasty, thus causing inferior clinical scores. It provided useful information about the biomechanical role of the patella in total knee arthroplasty, allowing to choose the most appropriate surgical approach.
  
  
  METHODS
  Case series, Level IV.
authors: Biomechanics and Technological Innovation Laboratory, Codivilla-Putti Research Center, Bologna University, Via Di Barbiano 1-10, 40136, Bologna, Italy, ibrahim.akkawi@studio.unibo.it.
authors: Ibrahim
authors: I
authors: Akkawi
authors: Francesca
authors: F
authors: Colle
authors: Danilo
authors: D
authors: Bruni
authors: Giovanni Francesco
authors: GF
authors: Raspugli
authors: Simone
authors: S
authors: Bignozzi
authors: Stefano
authors: S
authors: Zaffagnini
authors: Francesco
authors: F
authors: Iacono
authors: Maurilio
authors: M
authors: Marcacci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods*; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D010329:Patella / Q000502:physiology*; D017847:Patellar Ligament / Q000502:physiology*; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology; D025321:Surgery, Computer-Assisted