title: Discovery Elbow System: clinical and radiological results after 2- to 10-year follow-up.
abstract: BACKGROUND
  Discovery Elbow System (DES) is a semi-constrained prosthesis, mainly used for patients with rheumatoid arthritis (RA).
  
  
  METHODS
  Records from 79 patients with RA (90 DES arthroplasties) were reviewed; 47 patients with 55 DES elbows were re-examined. Range of motion (ROM) of both elbows, upper limb function, and quality of life (Disabilities of the Arm, Shoulder, and Hand [DASH] score, Mayo Elbow Performance Score [MEPS], and the RAND 36-Item Health Survey [RAND-36]) were assessed. Cementing quality was assessed, and radiolucent lines measured from plain radiographs. Mean follow-up was 64 (range 24-123) months.
  
  
  RESULTS
  Pre-operatively to post-operatively, mean elbow flexion improved from 120° to 146° (p < 0.001) and mean extension lag improved from 29° to 24° (p = 0.02), respectively. At follow-up, mean supination was 66°, mean pronation was 69°, and mean grip strength was 14 kg. Grip strength and ROM (except supination) were similar between the DES elbow and contralateral un-operated elbow. Mean post-operative MEPS was 93 points (excellent, n = 38; good, n = 14; fair, n = 2; and poor, n = 1). Mean DASH score was 43 points. The RAND-36 showed that physical functioning, physical role functioning, bodily pain, and general health were lower than the Finnish reference values. Primary cementing was challenging, and radiolucent lines appeared during follow-up. Four prostheses were revised because of aseptic loosening (n = 3) and periprosthetic fracture (n = 1).
  
  
  CONCLUSIONS
  DES provides significant improvement in patient's flexion-extension arc. Cementing of the elbow prosthesis was challenging; radiolucent lines appeared during the 5-year follow-up, but their clinical relevance remains unclear. First-generation locking screws may loosen over time.
  
  
  METHODS
  Level IV.
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department of Surgery, Medical Research Center, Oulu, Oulu University Hospital, University of Oulu, PL 21, 90029 OYS, Oulu, Finland. patrik.hanninen@lshp.fi.
authors.forename: Patrik
authors.initials: P
authors.lastname: Hänninen
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department of Surgery, Medical Research Center, Oulu, Oulu University Hospital, University of Oulu, PL 21, 90029 OYS, Oulu, Finland.
authors.forename: Tuukka
authors.initials: T
authors.lastname: Niinimäki
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department of Surgery, Medical Research Center, Oulu, Oulu University Hospital, University of Oulu, PL 21, 90029 OYS, Oulu, Finland.
authors.forename: Tapio
authors.initials: T
authors.lastname: Flinkkilä
authors.affiliation: Research Unit of Medical Imaging, Physics and Technology, Medical Research Center, Oulu, Oulu University Hospital, University of Oulu, Oulu, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Niinimäki
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department of Surgery, Medical Research Center, Oulu, Oulu University Hospital, University of Oulu, PL 21, 90029 OYS, Oulu, Finland.
authors.forename: Pasi
authors.initials: P
authors.lastname: Ohtonen
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department of Surgery, Medical Research Center, Oulu, Oulu University Hospital, University of Oulu, PL 21, 90029 OYS, Oulu, Finland.
authors.forename: Susanna
authors.initials: S
authors.lastname: Yli-Luukko
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department of Surgery, Medical Research Center, Oulu, Oulu University Hospital, University of Oulu, PL 21, 90029 OYS, Oulu, Finland.
authors.forename: Juhana
authors.initials: J
authors.lastname: Leppilahti
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D057929:Arthroplasty, Replacement, Elbow; D004185:Disability Evaluation; D004551:Elbow Joint / Q000000981:diagnostic imaging / Q000601:surgery; D058569:Elbow Prosthesis; D005500:Follow-Up Studies; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D057068:Periprosthetic Fractures / Q000209:etiology / Q000503:physiopathology; D011403:Pronation / Q000502:physiology; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D011788:Quality of Life; D011859:Radiography; D012189:Retrospective Studies; D013484:Supination / Q000502:physiology
keywords: Cementing; Discovery Elbow System; Radiolucent lines; Rheumatoid arthritis; Semi-constrained; Total elbow arthroplasty