[Ortho] Periprosthetic fx dislocation after THR

[Chris Wilson]

This what a hip colleague of mine thinks

Chris Wilson
University Hospital
Cardiff
UK


Good case - Problems are :

1. Dislocation - as it was through Lat approach abductor  repair will also have failed
2. Fracture - In terms of classification doesn't fit neatly into Vancouver Classification because both lesser & greater trochanters are fractured - therefore is AL & AG. 
Medial fracture line extends into diaphysis and would therefore be more accurately defined as a B fracture. The stem looks like a Zimmer proximally coated FMT therefore as it is only 2 days post-op & given the morphology of the fracture probably best described as a B2 fracture around loose stem.

Treatment - Revision surgery to include -

1. Stem revision to stem which allowed distal fixation - ie fully coated porous or tapered distal fixation stem.
2. Reduction of medial calcar fragment & greater 
trochanter probably best achieved with rochanteric cable plate system
3. Regarding instability - offset was obviously an issue in primary surgery given long neck skirted head. Therefore I would advise careful intra-operative assessment of socket position and abductor damage. If component position poor then revisie socket if not increase head size to 36mm 
(which will also lateralise liner helping offset) or if abductor damage significant consider constrained liner (the Trilogy socket that is in place will allow for both these options).

Cheers - Steve
Chris Wilson