[Revision hip stems: an analysis of the fixation].
BACKGROUND
Revision hip replacements are complicated surgeries because the femoral quality is often reduced by large substance losses. Stem fixation in terms of sufficient primary stability is therefore a great challenge for the orthopaedic surgeon.


OBJECTIVE
The aim of the present study was to examine two currently used prostheses in Germany (MHP and MRP) concerning their ability to securely bridge femoral defects.


RESULTS
Up to a segmental metaphyseal defect, both stems showed sufficient fixation in our experimental setup. However, because of its predominantly distal fixation, the MRP stem would unnecessarily bridge proximal bone areas still capable of load bearing. In the presence of a transfemoral approach, the surgeon should favour the distal fixation mode because in this situation the proximal fixation option is absent. Therefore, the isthmus takes a key role for both stem designs.
Thomsen
M
M
Abteilung Orthopädie, DRK-Klinik Baden-Baden, Baden-Baden, Deutschland.
Kretzer
J P
JP
Heisel
C
C
Lee
C
C
Nadorf
J
J
Jakubowitz
E
E
D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D006801:Humans; D016268:Internal Fixators; D011474:Prosthesis Design; D012086:Reoperation / Q000295:instrumentation
Arch Orthop Trauma Surg. 2004 Jun;124(5):306-9
15064958
J Arthroplasty. 1998 Aug;13(5):535-45
9726319
Herzschrittmacherther Elektrophysiol. 2007 Sep;18(3):166-93
17891493
Clin Orthop Relat Res. 1986 Jul;(208):108-13
3720113
Instr Course Lect. 2000;49:83-96
10829164
J Bone Joint Surg Am. 2003 Jan;85(1):109-14
12533580
J Biomech. 1993 Aug;26(8):969-90
8349721
Int Orthop. 2000;24(3):134-8
10990382
Acta Orthop Scand. 2000 Apr;71(2):111-21
10852315
J Orthop Trauma. 2000 Nov;14(8):546-53
11149500
Clin Orthop Relat Res. 1994 Jan;(298):119-26
8118966
J Biomed Mater Res. 1977 Nov;11(6):811-38
591524
J Biomech Eng. 2002 Dec;124(6):706-13
12596639
Orthopade. 1989 Sep;18(5):344-9
2682454
Unfallchirurg. 2001 Jul;104(7):622-8
11490955
Z Orthop Ihre Grenzgeb. 1996 Mar-Apr;134(2):99-110
8779267
J Bone Joint Surg Am. 1989 Jun;71(5):716-8
2732261
Orthopade. 2004 Jan;33(1):63-7
14747912
Clin Orthop Relat Res. 1993 Nov;(296):133-9
8222415
Unfallchirurgie. 1993 Feb;19(1):11-5
8465463
Z Orthop Ihre Grenzgeb. 2004 May-Jun;142(3):314-21
15250004
J Bone Joint Surg Am. 1978 Apr;60(3):306-13
649633
Unfallchirurg. 2000 Jun;103(6):444-51
10925646