Orthodynamics | CUT Femoral Neck Prosthesis | Which Medical Device

Description

From Which Medical Device

The CUT femoral neck endoprosthesis is a short stem device with a modular dual cone proximal component that allows the selection of different offsets and versions once the stem has been implanted. The implant is made from CoCrMo alloy and has a macroporous structure. The stem is curved at the tip, to sit against the lateral cortex of the femur, and appears to better load the proximal femur than other more conventional stems (1).

The results of this implant have been variable.  Steens et al quote a 5 year survival rate of 98% at an average of 6.6 years, but reported technical issues with this implant include valgus/varus malalignment, with undersized components tending to drift into valgus, and occasional revision required because of lack of offset (2).  Other authors have reported much lower survival; Ender et al reported a 5 year survival of 89%, and Ishaque et al reported 8 year survival of 49.6% (3,4).

For further information on short femoral stems, read our article on What's Available in Short Stem Hip replacements.

References:

(1) Decking R , Rokahr C , Zurstegge M, Simon U, Decking J. Maintenance of bone mineral density after implantation of a femoral neck hip prosthesis. BMC Musculoskeletal Disorders 2008, 9:17doi:10.1186/1471-2474-9-17

(2) Steens W, Skripitz R, Schneeberger AG, Petzing I, Simon U, Goetze C.
[Cementless femoral neck prosthesis CUT--clinical and radiological results after 5 years]. [Article in German]. Z Orthop Unfall. 2010 Aug;148(4):413-9. Epub 2010 Aug 16. 

(3) Ender SA, Machner A, Pap G, Hubbe J, Grashoff H, Neumann HW.
Cementless CUT femoral neck prosthesis: increased rate of aseptic loosening after 5 years. Acta Orthop. 2007 Oct;78(5):616-21.

(4) Ishaque BA, Donle E, Gils J, Wienbeck S, Basad E, Stürz H.[Eight-year results of the femoral neck prosthesis ESKA-CUT]. [Article in German]. Z Orthop Unfall. 2009 Mar-Apr;147(2):158-65. Epub 2009 Apr 8.