A Randomized Controlled Trial of Kinematically and Mechanically Aligned Total Knee Arthroplasties: Long-Term Follow-Up.

BACKGROUND: The optimal alignment technique for total knee arthroplasty (TKA) remains controversial. We previously reported 6-month and 2-year results of a randomized controlled trial comparing kinematically versus mechanically aligned TKA. In the present study, we report the mean 13-year (range, 12.6-14.4) follow-up results from this trial. METHODS: The original cohort included 88 TKAs (44 kinematically aligned using patient-specific guides and 44 mechanically aligned using conventional instrumentation), performed from 2008 to 2009. After institutional review board approval, the health records of the original 88 patients were queried. Revisions, reoperations, and complications were recorded. There were 26 patients who died, leaving 62 patients for follow-up. Of these, 48 patients (77%) were successfully contacted via phone. Reoperations and complications were documented. Furthermore, a battery of patient-reported outcome measures (PROMs) (including Western Ontario and McMaster University Index, Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score Junior, Forgotten Joint Score, Modified-Single Assessment Numerical Evaluation, and patient satisfaction) were obtained. RESULTS: Of the original 88 patients in the study, 15 patients had at least one reoperation (17%) and 5 patients had undergone complete revision surgery (6%). There was no difference between the 2 alignment methods for major and minor reoperations (P = .66). The kinematically aligned total knees self-reported a nonstatistically significant (P = .16) improved satisfaction (96% versus 82%), but no difference in other PROMs compared to mechanically aligned TKAs. CONCLUSION: Kinematically aligned TKA demonstrates excellent mean 13-year results, comparable to mechanically aligned TKA with similar reoperations, complications, and PROMs.

Improving Care and Reducing Length of Stay in Patients Undergoing Total Knee Replacement.

A team approach to orthopedic surgery process improvement helped reduce length of stay without increasing 30-day readmission rates.

Kinematically versus mechanically aligned total knee arthroplasty.

The purpose of this study was to compare 2 alignment methods for total knee arthroplasty (TKA): kinematic alignment with the use of patient-specific guides and mechanical alignment with conventional instruments. A randomized, controlled trial of 41 kinematically aligned and 41 mechanically aligned patients was conducted with the patient, radiographic evaluator, and clinical evaluator blinded to the alignment technique. Radiographic measurements were made from long-leg computer tomography scanograms. Clinical outcome scores and motion were measured preoperatively and 6 months postoperatively. The hip-knee-ankle angle (0.3° difference; P=.693) and anatomic angle of the knee (0.8° difference; P=.131) were similar for both groups. In the kinematically aligned group, the angle of the femoral component was 2.4° more valgus (P<.000) and the angle of the tibial component was 2.3° more varus (P<.000) than the mechanically aligned group. At 6 months postoperatively, the Western Ontario and McMaster Universities Osteoarthritis Index score was 16 points better (P<.000), Oxford Score was 7 points better (P=.001), combined Knee Society Score was 25 points better (P=.001), and flexion was 5.0° greater (P=.043) in the kinematically aligned group than in the mechanically aligned group.Our findings suggest that the risk of early failure related to limb or knee alignment should be similar in kinematic and mechanically aligned TKA. More anatomic alignment of the implant was associated with better flexion and better clinical outcome scores in the kinematically aligned group.