Format

Send to

Choose Destination
Int Orthop. 2009 Dec;33(6):1513-8. doi: 10.1007/s00264-008-0710-0. Epub 2008 Dec 20.

The influence of the centre of rotation on implant survival using a modular stem hip prosthesis.

Author information

1
1st Department of Orthopaedic Surgery and Laboratory of Medical Technology (LTM), Istituti Ortopedici Rizzoli, Via Pupilli 1, Bologna, Italy, 40136. traina@tecno.ior.it

Abstract

The restoration of the hip centre of rotation in an anatomical position is considered to be relevant for total hip prosthesis survival. When the cup is implanted with a high centre of rotation, the lever arm of the abductor muscles is decreased, causing higher joint-reaction forces. Modular stems with varying lengths and geometries can be used to balance soft tissues, and ceramic bearing surfaces can be used to reduce the wear rate. Forty-four hip replacements performed with a high hip centre of rotation were matched with 44 performed with an anatomical centre of rotation. In all cases the preoperative diagnosis was dysplasia of the hip (DDH) and cementless modular neck prostheses with ceramic bearing surfaces were used. At nine years follow-up the mean Harris hip and WOMAC scores were not statistically different. All stems and cups were stable; the femoral offset was no different between the two groups (p = 0.4) as leg-length discrepancy (p = 0.25).

PMID:
19099304
PMCID:
PMC2899177
DOI:
10.1007/s00264-008-0710-0
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Springer Icon for PubMed Central
Loading ...
Support Center