[Long-term results of uncemented Parhofer-Mönch screw rings].
OBJECTIVE
The aim of this study was an analysis of the long-term behaviour and implant migration of the Parhofer-Mönch-screw cup seen in patients between 1982 and 1991.


METHODS
92 cups (m : f = 53 : 39, mean age 53 +/- 7 years) were included mainly prospectively. After 118 +/- 45 months all patients were examined clinically and radiologically. Digital migration analysis was performed using the single-film X-ray analysis (Einbildröntgenanalyse, EBRA).


RESULTS
5 patients had died. 32 cups were revised, in 7 patients a loosening of the cup was suspected. The 10-year-survival was 71.4 %. In 53 of 81 analysed cups a migration of more than 1 mm was shown, 28 cups did not migrate. In comparison to these stable implants the survival of migrated cups was significantly inferior.


CONCLUSIONS
The 10-year-survival and the high rate of implant migration document the poor results of the PM cup. In spite of an extraordinary primary stability, the failure of secondary osseointegration represents the main cause of loosening in this type of cup.
Hendrich
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C
Orthopädischen Universitätsklinik Würzburg, König-Ludwig-Haus. c-hendrich.klh@mail.uni-wuerzburg.de
Ak
D
D
Sauer
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U
Kirschner
S
S
Rader
C P
CP
D001863:Bone Screws / Q000009:adverse effects*; D002484:Cementation; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000209:etiology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D011859:Radiography; D016896:Treatment Outcome