A DePuy knee replacement lawsuit is a product liability claim, filed individually rather than as a class action, alleging that the Attune Knee System’s tibial baseplate loosens prematurely because surgical cement cannot bond properly to its underside. The first case was filed in Alabama in September 2017, and patients have continued to bring individual suits since. There is no multidistrict litigation, no group settlement, and no publicly disclosed verdicts as of early 2026.1Drugwatch. Knee Replacement Lawsuits
What the Lawsuits Allege
The claims focus on one design feature: the underside of the first-generation Attune tibial tray. Plaintiffs say it is too smooth for cement to grip. The original tray had a surface roughness roughly 75 percent lower than DePuy’s previous-generation implant and lacked the cement pockets and textured coating found on older designs.2PMC (National Library of Medicine). Design Flaw in Attune Tibial Component Undersurface When the cement-to-implant bond breaks, the tibial component loosens inside the knee. Surgeons call it debonding or aseptic loosening.
A 2017 study in the Journal of Knee Surgery by Peter Bonutti and colleagues put the problem on the map. Reviewing 15 revision cases from three hospital databases, the researchers found that in every case the tibial component had separated cleanly from the cement while the cement stayed firmly attached to the bone.3Thieme Connect. Unusually High Rate of Early Failure of Tibial Component in Attune Total Knee Arthroplasty System at Implant-Cement Interface Standard X-rays caught the loosening in only two of the 15 knees, leading the authors to conclude the problem was likely “markedly underreported.”4Thieme Connect. Unusually High Rate of Early Failure of Tibial Component in Attune TKA System (PDF) By June 2017, the FDA’s MAUDE database had logged approximately 1,400 adverse event reports tied to the Attune system, 633 of them involving revision surgery.5AboutLawsuits.com. Knee Replacement Lawsuits
Injuries That Support a Claim
When the tibial baseplate separates from the cement, complications reported by patients include debilitating pain (especially with weight-bearing), swelling and inflammation, joint instability, decreased range of motion, infection, bone loss, blood clots, and nerve damage.6ConsumerNotice.org. Knee Replacement Lawsuits These failures have often occurred within two years of the original surgery, well short of the 12-to-20-year lifespan a knee implant is expected to provide.5AboutLawsuits.com. Knee Replacement Lawsuits
Almost all failed implants require revision surgery. Revision is more complex than the original knee replacement, with recovery reportedly up to 50 percent longer and extensive physical and occupational therapy on the back end.6ConsumerNotice.org. Knee Replacement Lawsuits The revision surgery is usually the injury a plaintiff points to when explaining damages.
Where the Litigation Stands
The first known Attune knee lawsuit was filed on September 13, 2017, in the Circuit Court of Tuscaloosa County, Alabama, by the law firm Cunningham Bounds.7PR Newswire. Cunningham Bounds Files Lawsuit Against DePuy Due to Attune Knee Replacement Failure The case was removed to the U.S. District Court for the Northern District of Alabama and captioned Jones v. DePuy Synthes Products, Inc., Case No. 7:17-cv-01778-LSC. In November 2018, Judge L. Scott Coogler denied DePuy’s motion to strike the plaintiffs’ class allegations, finding it premature to rule out a nationwide class before discovery, and allowed the individual claims to be amended.8Cunningham Bounds. Jones v. DePuy Synthes Products Inc., Memorandum of Opinion and Order
Other individual suits followed across the country, but the cases have never been consolidated. Federal courts have no active MDL for the Attune or for any other knee replacement device.1Drugwatch. Knee Replacement Lawsuits No large group settlement has been announced, and no individual settlement figures or jury verdicts appear in the available record. Each plaintiff pursues damages on the facts of their own implant, their own revision, and their own state’s product liability law.
What the Clinical Evidence Shows
The scientific picture is more mixed than the litigation framing suggests, and any lawyer evaluating a case will look at it. The Bonutti study raised valid concerns about underreporting, but larger analyses have tempered the picture. A 2023 retrospective study of over 10,200 knee replacements, presented at the British Orthopaedic Research Society meeting, compared the Attune to DePuy’s older PFC Sigma design and to other cemented implants and found no statistically significant difference in revision rates, aseptic loosening rates, or tibial loosening rates. The Attune’s revision rate was actually slightly lower than the Sigma’s (2.98 versus 3.15 per 1,000 implant-years).9Bone & Joint. Attune Total Knee Replacement: Is There Evidence of Increased Tibial Component Loosening?
DePuy also redesigned the tray. Around 2020, the company introduced the second-generation Attune S+ tibial baseplate, with a “Macrolock” design featuring four cement pockets cut at 45-degree undercuts and a microblasted surface to increase roughness.10Johnson & Johnson MedTech. Attune S+ Technology A 2026 study of 500 consecutive Attune implants in the Journal of Orthopaedic Surgery and Research found all three cases of tibial tray loosening occurred in patients with the first-generation Legacy tray, and none in patients who received the S+ design.11PMC (National Library of Medicine). A Study of 500 Consecutive Attune Knee Implants, Assessing Early Outcomes and Failure Rates Practically, the strongest debonding cases involve the older Legacy tray implanted before the redesign.
The Sigma Knee Track Is Separate
DePuy’s older Sigma knee system, approved in 1996 and implanted in an estimated 1.7 million patients, has its own litigation. The first Sigma suit was filed in 2018, with plaintiffs alleging joint instability, pain, early wear, and the need for revision surgery.12Seeger Weiss. DePuy Knee Replacement Lawsuit A December 2017 recall pulled 7,500 Sigma HP PFJ Cemented Trochlear Implants over elevated revision rates.13Drugwatch. Knee Replacement Recalls The Sigma and Attune cases involve different products and different defect theories, and they are being pursued on separate tracks.
The J&J Orthopedics Sale May Affect Who Pays
In October 2025, Johnson & Johnson announced plans to separate DePuy Synthes into a standalone company. By February 2026, J&J was reportedly exploring an outright sale of the orthopedics unit for more than $20 billion, with the separation expected by mid-to-late 2027.14Reuters. Johnson & Johnson Explores Sale of Orthopedics Unit15MedDeviceGuide. J&J DePuy Synthes Sale Orthopedics Divestiture Guide How pending Attune and Sigma liability would be allocated between J&J and any new entity is not clear from the available reporting. It is a moving piece worth watching if you are considering a claim.
How to File a Claim
Knee replacement lawsuits are filed individually, not as class actions. To pursue one, you generally need to have received a DePuy Attune or Sigma implant and to have experienced complications such as early device failure, severe pain, infection, bone loss, instability, or the need for revision surgery. Claims are brought under product liability theories: defective design, manufacturing defects, or failure to warn. Plaintiffs may seek damages for medical expenses, lost wages, pain and suffering, and related losses.16Top Class Actions. Who Is Eligible to File a DePuy Attune Lawsuit
Deadlines matter. Statutes of limitations vary by state, and the specific filing window depends on when you knew or should have known your injury was tied to the implant. Gather your operative reports, implant identification cards, and revision surgery records, and speak with a product liability attorney before the clock runs out.