Recall of medical devices - DePuy ASR™ Hip Resurfacing System and DePuy ASR™ XL Acetabular System

DePuy Orthopaedics conducted a global voluntary recall on 31 August 2010 of its DePuy ASR™ Hip Resurfacing System and DePuy ASR™ XL Acetabular System due to its association with higher rates of revision surgery. These are medical devices used in hip resurfacing and replacement surgeries.

Background

The DePuy ASR™ XL Acetabular System is used in hip replacement surgeries for people with hip joint damage from arthritis or injuries. It comprises of the acetabular cup, which is a metal liner that replaces the socket portion of the pelvis, known as the acetabulum.

The DePuy ASR™ Hip Resurfacing System consists of two components, (i) a cap which is placed over the femoral head and (ii) the acetabular cup. Unlike in conventional hip replacement surgery where the femoral head is replaced, resurfacing of the hip preserves the femoral bone by placing a metal cap over the surface of the femoral head. The femoral head and neck are not removed. The acetabulum is replaced with the acetabular cup as in a total hip replacement surgery. Both ASR™ systems had been marketed locally since 2006.

DePuy Orthopaedics issued a notification or ‘Field Safety Notice' in March 2010 to healthcare professionals following an analysis of post-marketing data, which suggested that a higher than expected number of patients who received the ASR™ systems required a second hip replacement surgery, i.e. revision surgery. A revision surgery is required in instances where there are mechanical faults in the artificial hip, warranting the removal of old implants and replacing them with new components.

Subsequently on 31 August 2010, DePuy Orthopaedics issued a voluntary global recall of its ASR™ XL Acetabular System and ASR™ Hip Resurfacing System due to higher rates of revision surgery observed in DePuy ASR™ products taking into account the data from the National Joint Registry (NJR) of England and Wales.

Data from the National Joint Registry (NJR) of England and Wales

In May 2010, the NJR of England and Wales informed the UK Medicines and Healthcare products Regulatory Agency (MHRA) that ASR™ acetabular cups had been identified from registry data as having higher than anticipated rates of revision surgery in hip resurfacing and total hip replacement procedures.

The NJR of England and Wales had carried out an analysis on outcomes following primary hip replacement based on data for 216,693 patients who had primary hip replacement procedures between 1 April 2003 and 31 December 2009. The analysis showed that the overall revision surgery rate following primary hip replacement was 1.0%, 2.1% and 2.9% at one, three and five years respectively.¹

Data from the NJR also revealed that the revision surgery rate at five years for patients who had received DePuy ASR™ Hip Resurfacing System and DePuy ASR™ XL Acetabular System, were higher thanexpected across the entire size range at 12% and 13% respectively (approximately 1 in 8 patients). The risk for revision surgery was noted to be highest with use of ASR™ head sizes below 50 mm in diameter and among female patients.

Adverse effects experienced by affected patients

Patients who reported problems with the DePuy ASR™ systems and required revision surgeries within the first five years post-surgery presented with a variety of symptoms including pain, swelling and difficulty in walking. A small number of patients implanted with these systems may also develop progressive soft tissue reactions to the metal debris generated as the metal components wear out over time.² While this condition may initially be painless, if left untreated, this reaction may cause pain and swelling around the joint and could damage some of the muscles, bones and nerves around the hip.³

Local situation

To date, 319 units of the ASR™ systems had been implanted locally, of which one case was reported to require revision surgery. However, further investigations had shown that the cause for revision surgery was not implant-related.

DePuy Orthopaedics has also implemented a series of recommended follow-up actions for patients implanted with the DePuy ASR™ Hip systems such as an annual follow-up for at least five years post-operatively and closer monitoring with necessary blood tests and MRI or ultrasound scans.

Healthcare professionals are encouraged to report adverse events suspected to be associated with the DePuy ASR™ systems or other medical devices to the Medical Device Branch of HSA.

[Note: Following the gazetting of the Health Products (Medical Devices) Regulations 2010 and Health Products (Medical Devices) (Exemption) Order 2010 under the Health Products Act (Chapter 122D) on 10 August 2010, articles related to medical device safety will be published in this bulletin]

References

1. National Joint Registry for England and Wales 7th Annual Report
2. Medicines and Healthcare products Regulatory Agency.
   Medical Device Alert Ref: MDA/2010/033
3. Depuy website. http://www.depuy.com

Published: 16 Dec 2010

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