Introduction: The modular IBPSII prosthesis was introduced in 1989 with modifications to the patello-femoral articulation and the posterior stabilized mechanism.

Methods: 100 consecutive IBPSII knee arthroplasties were followed prospectively. Age, gender, deformity and diagnoses were comparable to previous groups.

Results: Fifty-one knees were evaluated at 10 or more years with the Knee Society scores and radiographs. 14 were evaluated by phone. An additional 6 knees required revision and 29 were in patients who died. None were lost. Revisions were performed for instability (2 knees), sepsis (2), loosening from osteolysis (1), and stiffness (1). In the 10-year group, 12 patients required reoperations: Patellar revision for loosening (1), patel-lectomy for fracture (1), polyethylene exchange for dislocation of the spine and cam mechanism (3) and for dissociation (1), and arthroscopic resection of scar from the quadriceps tendon (patellar clunk) in 6 knees.

Conclusion: The smoother patello-femoral groove was associated with fewer patellar fractures, but resulted in scar on the quadriceps catching on the femoral component. The tibial spine was moved posteriorly from previous models to increase rollback. This resulted in dislocation of the spine and cam mechanism. One case failed due to loosening and extensive osteolysis presumably associated with modularity. The last two complications were not observed with earlier versions of this prosthesis. All complications occurred within the first five years.