Early Results of a New Rotating Hinge Knee Implant

Abstract

Background. Indication for rotating hinge (RH) total knee arthroplasty (TKA) includes primary and revision cases, with contradictory results. The aim of this study was to report prospective early results of a new modular rotating hinge TKA (EnduRo). For this implant several new design features and a new bearing material (carbon-fiber reinforced poly-ether-ether-ketone) have been developed. Furthermore, we tried to establish a new classification of failure modes for revision TKA. Methods. 152 EnduRo rotating-hinge prostheses were implanted in two centers. In 90 patients a primary implantation has been performed and 62 patients were revision cases. Knee Society Score (KSS), Western Ontario and McMaster Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), and Range of motion (ROM) were assessed before surgery, 3 months postoperatively, 12 months postoperatively, and annually thereafter. We defined 3 types of complications: Type 1, infection; type 2, periprosthetic complications; type 3, implant failures. Results. KSS, WOMAC, OKS, and ROM revealed significant improvements between the preoperative and the follow-up investigations. There were 14 complications (9.2%) leading to revision surgery, predominantly type 2. Conclusion. Our study shows excellent clinical results of the EnduRo TKA. Furthermore, no premature material failure or unusual biological response to the new bearing material could be detected.

Midterm Results of a New Rotating Hinge Knee Implant: A 5-Year Follow-Up

“…Furthermore the prosthesis provides an offset option for femoral and tibial stems. Cemented and cementless stem fixation are both possible, whereas the epiphyseal fixation of the implant has to always be cemented [ 20 ].…”

“…Radiographic analysis included assessment of alignment and signs of loosening (radiolucent lines, osteolysis, PE wear, and implant migration). Furthermore, we evaluated complications leading to revision surgery of the involved knee and differentiated between three different types of complications as previously described [ 20 ]: type 1, PJI; type 2, periprosthetic complications such as failure of the extensor mechanism, periprosthetic fractures, patella failure, and wound dehiscence; type 3, implant complications like wear, aseptic loosening, instability, and implant failure (including breakage of axis, bushings, and stem). This particular differentiation originates from the observation that the implant has no or little influence on type 1 (septic) and type 2 (periprosthetic complications) failures, whereas type 3 failures are specifically linked to the prosthesis and therefore provide information about implant survival [ 20 ].…”

“…After early result evaluation [ 20 ], in the current study we investigated midterm clinical, functional, and radiological outcomes, complications, and implant survival of a new third-generation rotating hinge prosthesis (EnduRo prosthesis; Aesculap AG, Tuttlingen, Germany), which uses a new bearing material (carbon-fiber reinforced poly-ether-ether-ketone, CFR PEEK) in complex primary and revision patients. Furthermore we aimed to compare outcomes and complications between primary and revision implantation and analysed risk factors for complications.…”

Total knee arthroplasty using hinge joints: Indications and results

“…In 2014, Giurea et al analysed 152 EnduRo rotating hinge prostheses (90 primary arthroplasties, 62 revisions). 44 Knee Society Score (KSS), Western Ontario and McMaster Osteoarthritis Index (WOMAC), OKS and ROM were evaluated before surgery, three months post-operatively, 12 months post-operatively and annually thereafter. KSS, WOMAC, OKS and ROM showed significant improvements between the pre-operative and the follow-up evaluations.…”

Analysis of Carbon Fiber Reinforced PEEK Hinge Mechanism Articulation Components in a Rotating Hinge Knee Design: A Comparison of In Vitro and Retrieval Findings

“…The RHK design EnduRo® (Aesculap AG Tuttlingen, Germany) with flanges and bushings made of CFR-PEEK was clinically introduced in November 2008 and has already shown satisfying results [20]. Moreover, the biological activity in vivo of CFR-PEEK debris was reported to be comparable to PE debris [21, 22].…”