Up to 200 people in Northern Ireland who have had hip replacements may have to endure surgery after an implant was withdrawn due to safety concerns.
The ASR hip system, made by the US company DePuy Orthopaedics, is used worldwide.
It was withdrawn by the company last month after it emerged more people than expected who received the ASR hip system have been experiencing problems following surgery.
A spokeswoman for the Belfast Health Trust said all those affected had been contacted but not everyone had been reviewed by a consultant yet.
Affected patients have reported symptoms such as pain, swelling, audible ‘popping' and difficulty when walking.
A message on the DePuy website says: “DePuy makes patient safety a top priority and is continually evaluating data about its products, including the ASR hip system.
“Most ASR hip replacement surgeries have been successful. However, data recently received by the company shows that more people than expected who received the ASR Hip System experienced pain and other symptoms that led to a second hip replacement surgery, called a revision surgery.
“For this reason, DePuy Orthopaedics is voluntarily recalling its ASR XL Acetabular System and DePuy ASR Hip Resurfacing System.
“This recall means additional testing and treatment may be necessary to ensure the hip is functioning well. In some cases, patients may need additional surgery.”