Tips and Pearls
The Exeter V40 stem (Stryker, Newbury, UK) is the most commonly inserted cemented stem in total hip arthroplasty in the United Kingdom. Revision rates are between 1.31% and 4.07% at 10 years depending on the cup component used.1 Several purpose-made stem extractors have been developed to remove the stem in revision, but these are not always available. In our department we often place a punch or a Bristow osteotome on the neck of the prosthesis in an attempt to dislodge the stem from its cement mantle. This can be difficult, especially in the obese patient, where soft tissues make application of a force parallel with the long axis of the femoral stem difficult or impossible. This frequently results in unnecessary delays in stem extraction, and can increase the risk of iatrogenic femoral fractures.
The patient is positioned as standard for revision total hip replacement. A standard approach to the hip is then used and cement is cleared from above the shoulder of the prosthesis using the preoperative radiographs as a reference. The joint is then dislocated and the femoral head is removed with a punch.
We have found that it is then possible to easily dislodge an Exeter V40 stem in an obese patient using the Exeter offset broach handle (Stryker) (Fig. 1). The handle is readily available and is compatible with all stem offset sizes. It is used to manually grip the trunion of the stem using one hand (Fig. 2), while a mallet held in the other hand is used to dislodge the stem by controlled blows against the impaction plate of the broach introducer (Video, Supplemental Digital Content 1, http://links.lww.com/TIO/A12, which demonstrates stem removal). Because of differences is the shape of the neck between the femoral broach and definitive stem, the broach introducer will not lock shut over the definitive stem. It must therefore be clamped shut and held manually, during backslapping, or alternatively, could be held shut using surgical adhesive tape or sterile dressings in order to free up a hand (Fig. 3). This allows force to be applied to the prosthesis in line with the long axis of the femoral shaft, and in our experience easily dislodges the stem, usually on the first hammer strike.
Although the rate of revision of cemented Exeter stems is low, the high numbers inserted in the United Kingdom mean stem removal is commonplace, either for infection, or to aid access to the acetabulum during revision. Our technique provides a safe method to quickly and easily remove a cemented Exeter stem using equipment readily available in almost all UK orthopedic centers. It is likely that a similar technique could be used for other cemented stems using the appropriate broach introducers.
1. The NJR centre, National Joint Registry for England and Wales, 13th Annual Report, The NJR Centre, Hemel Hempstead. 2016.