Zimmer Biomet CPT Hip System Femoral Stem 12/14 Neck Taper Joint Statement
Zimmer Biomet has issued a Field Safety Notice advising that, as a cobalt chromium polished taper slip style stem, the CPT Hip System Femoral Stem 12/14 Neck Taper has been shown to have an increased risk of peri prosthetic fracture (PFF) when compared to other cemented femoral stem styles1. The company is amending the instructions for use (IFU) to reflect this and will phase out (discontinue)the implant from the UK market by the end of 2024.
Given the popularity of the CPT Hip System and its PFF rate of approximately 1.4% in the UK, which is more than twice the risk compared to a similar stainless steel PTS reference product - this issue has been considered by a joint meeting of the British Hip Society (BHS), the British Orthopaedic Association (BOA), the National Joint Registry (NJR) and the Medicines and Healthcare products Regulatory Agency (MHRA).
Although this implant remains available until the end the year, the BHS and BOA advise against its use for elective surgery except in exceptional circumstances. Surgeons should consider using an alternative prosthesis.
There may be certain indications, such as fracture neck of femur, where the surgeon considers that delaying treatment to find an alternative would not be in the patient’s best interest and so the use of the CPT stem would be justifiable.
It is considered at this time that there is no evidence to suggest that enhanced surveillance of asymptomatic recipients of this prosthesis would derive any benefit. However, recipients of this prosthesis will be advised of the increased, albeit low, risk associated with this implant.
The MHRA has also issued a Device Safety Information Communication and continues to monitor the issue. The BHS and BOA will continue to be keep this matter under review.
The MHRA Device Safety communication can be viewed here.
[1] Lamb JN, Jain S, King SW, West RM, Pandit HG. Risk Factors for Revision of Polished Taper-Slip Cemented Stems for Periprosthetic Femoral Fracture After Primary Total Hip Replacement: A Registry-Based Cohort Study from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. J Bone Joint Surg Am. 2020 Sep 16;102(18):1600-1608. doi: 10.2106/JBJS.19.01242. PMID: 32604382.