More than 100 people - most from Merseyside - are suing a medical company over the effects of hip implants that were withdawn a year ago.
Patients complained of pain and swelling, nerve, muscle and bone damage and blood poisoning, solicitors Gregory Arbams Davidson said.
The implant manufacturers DePuy have denied any liability.
The company voluntarily recalled the implants in August 2010, but said it was not over safety concerns.
DePuy's ASR implant, released in 2003, used a metal cup and socket instead of a plastic or ceramic cup, to replace a hip joint.
But patients reported problems with the cup and socket working loose.
'Sick with pain'
Stephen Ellis, 57, from Norris Green, Liverpool, who had a hip replacement in 2005, fears the loosening may have led to the poisoning of his bone and muscle.
"I woke up one morning and I was in agony," he said. "And, I felt sick, really sick with the pain.
"I feel like an old man - that's what I feel like - an old man in his eighties. And I feel robbed of my life."
Norman Sherrington, 67, from Mossley Hill, Liverpool, had a DePuy implant fitted six years ago but has needed another operation after being in continuing pain.
"If the hip was really bad I'd have to go down on all fours," he said.
Lisa Lunt, of Gregory Arbams Davidson, who is leading the legal team, said: "It's had a terrible effect on my clients psychologically. It's broken up relationships.
"And they've been told that they can't find any clinical reason for the problem, initially, and that the pain was in their head."
She added that some had even felt suicidal.
A statement from DePuy said: "Since the recall decision was made, we have worked to provide patients and surgeons with the information and support they need.
"DePuy is committed to addressing reasonable and customary costs of testing and treatment for reasons related to the recall, including revision surgery if necessary."
The company said the first decision to voluntarily withdraw the implant was not related to concerns about the product's safety.
The product was withdrawn because of "declining demand and to allow the company to focus on developing the next generation hip technologies to better meet the needs of patients and surgeons", the firm said.