Abstract
A novel design total knee arthroplasty (TKA) system has been introduced to improve
patient outcomes and increase longevity. However, we have encountered a high rate
of debonding of tibial implant–cement interface. In addition, multiple reports have
been filed in Manufacturer and User Facility Device Experience database (MAUDE) with
the same mechanism of failure. Therefore, we evaluated: clinical, radiographic, and
intraoperative findings of patients who received this system and required a revision
surgery, and findings from MAUDE database compiled to this date. We reviewed three
hospital databases for patients who had revision TKA for tibial loosening at the implant–cement
interface. This yielded 15 cases with a mean age of 61 years (range, 47–84). All patients
received a novel knee system at another institution. Radiographic analysis was performed
by treating orthopaedist. The MAUDE database was reviewed for reports of aseptic failure.
Patients presented with pain on weight bearing, effusion, and decreased range of motion
(ROM) within 2 years after surgery. Radiographic evaluation demonstrated loosening
of the tibial components in 2 of 15 knees. This included cruciate retaining, posterior
stabilized, fixed bearing, and rotating platform bearing designs. Intraoperative findings
demonstrated gross loosening of the tibial component at the implant–cement interface.
Femoral and patellar components were well fixed. There were 21 reports of tibial loosening
at the implant–cement interface in MAUDE database in the past 2 months alone. Numerous
other tibial failures were reported; however, the mechanisms of failures were not
specified. Tibial component loosening is a rare complication of cemented TKA at short-term
follow-up. Several possible reasons include increased constraint, reduced cement pockets,
and reduced keel rotational stabilizers. The tibial component, which has greater torsional
loads, has lower surface roughness than femoral component. We believe that this complication
is underreported due to failure of radiographs to assess loosening. In addition, MAUDE
database reporting is not consistent and competing companies cannot provide data on
the revised components. In patients who have negative workup for a painful joint,
one must consider the diagnosis of debonding.
Keywords
total knee arthroplasty - aseptic failure - MAUDE - Implant–cement interface
