title: Midterm results after unicompartmental knee replacement with all-polyethylene tibial component: a single surgeon experience.
abstract: OBJECTIVE
  The aim of this study was to determine the survival rate, the causes of failure, and the functional outcomes of an all-polyethylene tibial unicompartmental knee prosthesis.
  
  
  METHODS
  One hundred (100) nonselected, consecutive patients indicated for unicompartmental knee replacement for isolated medial knee compartment osteoarthritis by a single surgeon at a single institution from 2000 to 2004 were included in this study. Data was collected retrospectively at final follow-up from the hospital electronic database, including progress notes, demographic information, Hospital for Special Surgery (HSS) Knee Score, details on the surgical procedure, reoperations/revisions, and mortality. A survival analysis was performed to estimate the probability of survival over time.
  
  
  RESULTS
  The survival probability of the all-polyethylene UKA implant was 95.4 % after a mean follow-up of 8 years, which is comparable to reports from studies using metal-backed modular designs for UKA. The causes of failure were progression of arthritis in adjacent compartments (2 %) and loosening of the tibial component (2 %). The mean preoperative HSS knee score improved from 36.6 ± 14.3 to 76.6 ± 21.6 at latest follow-up (p < 0.0001).
  
  
  CONCLUSIONS
  In summary, an all-polyethylene tibial component has equivalent survivorship to modular designs. Implant selection does not seem to have great influence on the outcome, but rather the success depends on appropriate indications and surgical technique.
authors.affiliation: Department of Orthopaedic Surgery, Helios ENDO-Klinik, Holstenstr. 2, 22767, Hamburg, Germany. hawi.nael@mh-hannover.de.|Trauma Department of the Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625, Hannover, Germany. hawi.nael@mh-hannover.de.
authors.forename: Nael
authors.initials: N
authors.lastname: Hawi
authors.affiliation: Department of Orthopaedic Surgery, Helios ENDO-Klinik, Holstenstr. 2, 22767, Hamburg, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Plutat
authors.affiliation: Department of Orthopaedic Surgery, Helios ENDO-Klinik, Holstenstr. 2, 22767, Hamburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kendoff
authors.affiliation: Trauma Department of the Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Suero
authors.affiliation: Hospital for Special Surgery, New York, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Cross
authors.affiliation: Department of Orthopaedic Surgery, Helios ENDO-Klinik, Holstenstr. 2, 22767, Hamburg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Gehrke
authors.affiliation: Department of Orthopaedic Surgery, Helios ENDO-Klinik, Holstenstr. 2, 22767, Hamburg, Germany.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Citak
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D020370:Osteoarthritis, Knee / Q000601:surgery*; D020959:Polyethylene; D011474:Prosthesis Design; D012189:Retrospective Studies
chemical_list: D020959:Polyethylene
keywords: All-polyethylene tibial component; Failure analysis; Revision; Survival; UKA; Unicompartmental knee arthroplasty