- See:
THR Main Menu:
- Discussion:
-
evaluation of painful THR:
- when previously pain free hip becomes painful, suspect loosening;
- where as acetabular loosening tends to cause groin pain, femoral loosening tends to cause thigh pain;
- increased limp and shortening are signs of
subsidence;
- patient may need to use his hands to lift leg onto exam table;
- inability to perform straigt leg raises;
- patient may then complain that his leg has become increasingly externally rotated as the component sinks into retroversion;
- in a cemented hip, thigh pain of implant origin indicates
loosening, however, this is not necessarily the case with
uncemented stems;
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Types of Femoral Component Loosening:
-
cemented femoral component: loosening:
-
bending cantilever
-
calcar pivot: (distal toggle)
-
medial midstem pivot
-
pistoning:
- Radiologic Findings:
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radiology of press fit stems
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radiology of cemented stems
-
radiology of the acetabular component
- Differential Injections:
- intra-articular injection of marcaine can be used in the diagnosis of component loosening;
- in the study by RW Crawford et al 1997, 15 patients with a painful THR received a marcaine injection;
- 14 patients received relief with the injection and 13 of them were found to have loose components (either femoral and/or acetabular);
- it did not seem to matter whether components were cemented or press fit;
- hip was aspirated and any fluid obtained was sent for culture, and if fluid was not obtained then inject 5 ml of Hartman's syndrome and re-aspirate;
- after aspiration, 10 cc of marcaine is injected;
Intra-articular local anesthesia for pain after hip arthroplasty. RW Crawford et al. JBJS. Vol 79-B. No 5. Sep 1997. p 796.
