[The bicompartmental knee joint prosthesis Journey Deuce: failure analysis and optimization strategies].

BACKGROUND: The Journey Deuce bicompartmental knee system is intended for patients with medial and patellofemoral arthritis of the knee and is aimed at diversifying the treatment options for knee arthritis. The prosthesis consists of a combined femoral shield with a medial condylar resurfacing component and a fixed bearing unicondylar tibial knee prosthesis. The advantages of the Journey Deuce system compared to total knee arthroplasty (TKA) are the bone sparing and cruciate retaining implantation. Outcome studies and investigation with respect to success and revision rates are rare. Thus the aim of this study was to investigate the early functional outcome as well as the revision and complication rates in patients with a Journey Deuce prosthesis within the first 2 years.
METHODS: In this study 43 patients (25 female/18 male, average age 62.4 ± 8 years and mean body mass index27.3 ± 4.5 kg/m(2)) underwent bicompartmental knee arthroplasty using the Journey Deuce prosthesis between March 2008 and March 2009. Inclusion criteria were clinically and radiographically confirmed patellofemoral arthritis, ligament stability and flexion > 90°. Exclusion criteria were extension deficits > 5°, axis deviation > 10° and patellofemoral malalignment. Patients were followed up for 6, 12 and 24 months postoperatively. Follow-up consisted of clinical and radiographical examination as well as a survey of the Knee Society score (KSS), a pain score (visual analog scale VAS, range 0-10) and a satisfaction score.
RESULTS: Of the patients 35 (82%) patients reached the 2-year follow-up and of these 35 patients 26 (75%) had a good to very good satisfaction, a mean KSS of 93 (range 65-100) and a minimal pain score of 1.2 (range 0-4). After 12 months all patients had a knee flexion of more than 90° (mean 116°, range 95°-140°). Loosening was not detected but 8 (18%) patients had to undergo revision within the first year due to persistent knee pain and instability.
CONCLUSIONS: Under clear indications and exact anatomical positioning the Journey Deuce prosthesis enables a good functional outcome; however, a high revision rate occurred in this study caused by technical complexity and insufficient variety of implant sizes which led to malalignment and instability. Additional positional guidance and a higher variability in implant sizes are required to enable an adequate treatment with anatomically correct positioning. The Journey Deuce prosthesis would then be a reasonable diversification of the endoprosthesis spectrum in knee arthroplasty and would allow a more individual and selective treatment of patients with knee arthritis.