Summary

Large Corail uncemented stems have a higher rate of late peri-prosthetic fracture, Collared Stems are protective against these fractures.

Abstract

Background

The Corail hip stem is one of the most widely used uncemented stems for total hip
arthroplasty and has demonstrated excellent survivorship. This study aimed to investigate the
effects of both stem size and calcar collars on the rates of revision due to periprosthetic fracture.

Methods

All primary total hip arthroplasty (THA) procedures recorded by the Australian
Orthopaedic Association National Joint Replacement Registry (AOANJRR) from September 1999
to December 2021 for a diagnosis of osteoarthritis using the Corail stem with modern bearings
were included. The primary outcome measure was revision due to periprosthetic fracture. Stems
were divided into two groups for comparison, large (size 14-20) and small-medium (3-13). A sub
analysis was performed for collared stems.

Results

A total of 59,518 primary THA procedures were included. The cumulative percent
revision (CPR) for periprosthetic fracture was significantly higher for large stems when compared
to small-medium stems (Entire period HR = 1.57 (1.18, 2.09) p=0.002). Furthermore, collared
stems had significantly lower rates of revision due to late periprosthetic fracture when compared
to collarless variants (2wk + HR = 4.55 (3.23, 6.42), P<0.001). Large collarless stems were found
to have greater rates of revision due to fracture when compared to small-medium collarless stems
(Entire period HR =1.55 (1.13, 2.12) p=0.006), but no difference was found between collared
groups (Entire period HR = 1.37 (0.68, 2.78) p=0.382).

Conclusion

Large Corail stems have a higher rate of revision due to periprosthetic fracture when
compared to