title: Comparison of a novel porous titanium construct (Regenerex®) to a well proven porous coated tibial surface in cementless total knee arthroplasty - A prospective randomized RSA study with two-year follow-up.
abstract: BACKGROUND
  Regenerex is a novel porous titanium construct with a three-dimensional porous structure and biomechanical characteristics close to that of normal trabecular bone. The aim of this study was to compare this novel construct to a well-proven porous plasma sprayed tibial (PPS) implant after total knee arthroplasty.
  
  
  METHODS
  Sixty-one patients scheduled for an uncemented TKA were randomized to receive either a novel highly porous titanium construct Regenerex or the PPS tibial component. Radiostereometric analysis of the tibial components was performed postoperatively and at three, six, 12, and 24months with measurements of migration (segment motion and maximum total point motion (MTPM)).
  
  
  RESULTS
  Knee and function scores improved significantly from preoperatively to two-year follow-up. For both the Regenerex and the PPS the majority of migration appeared during the first three months and then stabilized. No statistically significant differences in MTPM were found in any follow-up between three and 24months. The Regenerex group had a lower migration rate between 12 and 24months compared with the PPS implants (p=0.03) but the PPS group had an initial significantly lower subsidence (p=0.04).
  
  
  CONCLUSIONS
  In conclusion the Regenerex implant could prove an effective scaffold material for coating of uncemented implants but did no better than the PPS component at 24months of follow-up. ClinicalTrials.gov identifier: NCT01936415.
authors: Department of Orthopaedics, Hillerød Hospital, Dyrehavevej 29, 3400 Hillerød, Denmark; Department of Orthopaedics Surgery, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen E, Denmark. Electronic address: Nikolajdoktor@gmail.com.
authors: Nikolaj S
authors: NS
authors: Winther
authors: Department of Orthopaedics Surgery, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen E, Denmark. Electronic address: clindkaer@gmail.com.
authors: Claus L
authors: CL
authors: Jensen
authors: Department of Orthopaedics Surgery, Gentofte Herlev Gentofte Hospital, Niels Andersens vej 65, 2900 Hellerup, Denmark. Electronic address: Claus.Munk.Jensen@regionh.dk.
authors: Claus M
authors: CM
authors: Jensen
authors: Department of Orthopaedics, Hillerød Hospital, Dyrehavevej 29, 3400 Hillerød, Denmark; Department of Orthopaedics Surgery, Gentofte Herlev Gentofte Hospital, Niels Andersens vej 65, 2900 Hellerup, Denmark. Electronic address: Thomas.Lind@regionh.dk.
authors: Thomas
authors: T
authors: Lind
authors: Department of Orthopaedics Surgery, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen E, Denmark. Electronic address: hemsc@regionsjaelland.dk.
authors: Henrik M
authors: HM
authors: Schrøder
authors: Department of Orthopedics Surgery, Skåne University Hospital, Lund University, S-221 85 Lund, Sweden. Electronic address: gunnar.flivik@med.lu.se.
authors: Gunnar
authors: G
authors: Flivik
authors: Department of Orthopaedics Surgery, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen E, Denmark. Electronic address: m.m.petersen@dadlnet.dk.
authors: Michael M
authors: MM
authors: Petersen
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D002484:Cementation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016062:Porosity; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D059869:Radiostereometric Analysis; D016059:Range of Motion, Articular; D013977:Tibia; D014025:Titanium
chemical_list: D014025:Titanium
keywords: Radiostereometric study; Randomized clinical trial; Regenerex; Total knee arthroplasty; Trabecular metal