Miller-Galante unicompartmental knee arthroplasty at 2- to 5-year follow-up evaluations

A consecutive series of 62 Miller-Galante (2immer, Warsaw, IN) unicompartmental knee arthroplasties were evaluated. Patients had unicompartmental degenerative arthritis or osteonecrosis, a sagittal plane deformity of 15 degrees or less, and minimal patellofemoral involvement. The average age was 69, with osteoarthritis in 85% and osteonecrosis in 15%. Ninety-five percent were medial and 5% lateral compartment replacements. The Hospital for Special Surgery knee score averaged 56 +/- 11 before surgery and 96 +/- 5 at the final follow-up evaluation, with an average postoperative pain score of 48 +/- 2. Three patients suffered intra-operative or immediate postoperative tibial plateau fractures without apparent sequelae, one patient required a postoperative manipulation under anesthesia, and one patient required an arthroscopic debridement for retained cement in the posterior capsular space. Limb alignment was corrected to within 5 degrees of the neutral mechanical axis in 77%, with 19% undercorrected and 3% overcorrected. Seventy percent of knees showed at least a single radiolucent line. Complete radiolucent lines were noted about three tibial components (6%) and progressive partial radiolucency was noted about four additional components (8%).