An asymptomatic, minimally displaced patella fracture was noted in 2 knees (7.4%).
Complications included 1 case of deep venous thrombosis and 2 knees that required a manipulation for stiffness.
Group 2 knees gained flexion more rapidly: At 6 weeks, the average flexion for was 94.5° for group 1 and 107.1° for group 2 (P<.001).
During the arthroscopic procedure, Outerbridge [19] stage 2 chondral lesions of the patella were observed in 5 knees (3 in 3 knees and 4 in 2 knees).
Group 1 knees (n = 83) were implanted with a prosthesis that has a multiradius femoral component, and group 2 knees (n = 101) were implanted with a femoral prosthesis that has a single flexion-extension axis.
Patients with group 2 knees had significantly less anterior knee pain when rising from a seated position starting at 6 weeks, and a difference was maintained through 2 years (1% vs 22%; P=.001).
Significantly more patients with group 2 knees were able to arise from a 16-inch (low) chair without using their arms starting at 6 weeks, and a difference was maintained through 2 years (90% vs 73%; P=.003).
There were late dislocations of the bearing in 2 knees, anterior soft tissue impingements in 6 knees at an earlier follow-up, excessive anteroposterior translation in 5 knees, and a fracture of the femoral component induced by osteolysis in 1 knee.
