title: High mid-term revision rate after treatment of large, full-thickness cartilage lesions and OA in the patellofemoral joint using a large inlay resurfacing prosthesis: HemiCAP-Wave®.
abstract: OBJECTIVE
  The HemiCAP-Wave® implant for the patellofemoral resurfacing treatment of large cartilage lesions and osteoarthritis (OA) was introduced in 2009. The outcome of a prospective cohort study of 18 patients with large trochlea lesions or isolated OA treated with the HemiCAP-Wave® implant is presented with up to a 6-year survival rate, and hypothesised short-to mid-term reduced pain and improved function.
  
  
  METHODS
  Indication for treatment with the HemiCAP-Wave® implant was a symptomatic, large cartilage lesion in trochlea demonstrated by MRI or arthroscopy, which was ICRS grades 3-4 and larger than 4 cm2. Patients were followed for 2 years with American Knee Society Subjective outcome Scores (AKSS), pain scores and radiographic evaluations and for up to 6 years with complications and reoperations.
  
  
  RESULTS
  At the 1- and 2-year follow-up mean AKSS clinical score, the mean AKSS function score and mean pain score improved significantly. Within 6 years, 28 % of the implants were revised to arthroplasty due to the progression of cartilage lesions, osteoarthritis or increased knee pain.
  
  
  CONCLUSIONS
  The present study demonstrated an improved short- to mid-term clinical outcome and reduced pain but high mid-term revision rate after patellofemoral inlay resurfacing using the HemiCAP-Wave® implant. Patellofemoral resurfacing implantation treatment with a large inlay prosthesis can offer temporary treatment for large isolated patellofemoral cartilage lesions or OA in younger patients with almost healthy cartilage in the other compartments who are not yet eligible for arthroplasty treatment.
  
  
  METHODS
  IV.
authors.affiliation: Department of Orthopedic Surgery and Emergency Department, County Hospital of South Jutland, Vimmelskaftet 16, 6470, Sydals, Denmark. jens.ole.laursen@rsyd.dk.
authors.forename: Jens Ole
authors.initials: JO
authors.lastname: Laursen
mesh_terms: D000328:Adult; D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D001182:Arthroscopy; D002356:Cartilage / Q000473:pathology* / Q000601:surgery; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010146:Pain / Q000601:surgery; D057071:Patellofemoral Joint / Q000601:surgery*; D011446:Prospective Studies; D019651:Plastic Surgery Procedures; D012086:Reoperation / Q000706:statistics & numerical data*; D016896:Treatment Outcome
keywords: Cartilage defects; Inlay resurfacing arthroplasty; Knee; Osteoarthritis; Patellofemoral joint replacement