Abstract
Fixation only of Vancouver B Proximal Femoral Fractures (PFF's), specifically with Cemented Taper Slip stems (CTS) with an intact bone cement interface, has been shown to have reduced blood transfusion requirements and reoperations, compared to revision arthroplasty. This potentially carries the risk of stem subsidence and loosening, which negatively impacts functional outcome. The incidence of stem subsidence and associated fracture morphology have not previously been reported.
We retrospectively reviewed all Vancouver B PFF's in primary THR around CTS stems treated with internal fixation only between June 2015 and March 2021 for fracture morphology (Low Spiral (LS), High Spiral (HS), Metaphyseal Split (MS) and Short Oblique (SO)), fracture union and stem subsidence. Interprosthetic fractures and inadequate follow up were excluded. Secondary outcomes were collected.
Out of 577 cases on our local periprosthetic database, 134 Vancouver B PFF's around CTS stems were identified, of which 77 patients underwent ORIF only. Of these, 50 procedures were identified, 21 were lost to follow up and 6 patients died before 6 months. Age, mortality rate and ASA is presented.
Review of Fracture morphology showed: 100% (3/3) of HS subsided (1 revised for loosening); 68 % (19/28) of MS subsided (1 revised for loosening); 11.1 % (2/18) of LS subsided (0 revised for loosening); 0% (1/1) of SO subsided. There were 2 revisions for non-union (LS group). No dislocations were recorded. There was a statistically significant association between Morphology and Subsidence P value 0.0004)
Major subsidence was observed in 8 patients (3 HS, 4 MS and 1 LS) which was associated with a significance reduction in mobility. Subsidence was associated with negative symptoms (P value < 0.0001).
Fixation of all Vancouver B PFF's does not produce uniformly good results. Revision rates following ORIF do not fully reflect patient outcomes. This trend will affect the NJR, stem rating and patient satisfaction. Subsidence after ORIF was associated with certain morphologies (HS & MS) and stem revision may be preferrable, in keeping with GIRFT. A morphology-based classification system can inform decision making.
