Abstract
BACKGROUND: for kinematic alignment (KA) total knee arthroplasty (TKA), it was unknown whether 'the pace of recovery' at six weeks was different for patients with ages ranging between 50-59, 60-69, 70-79, and 80-89 years who were discharged on the surgery day and self-administered their rehabilitation. METHODS: a single surgeon treated 206 consecutive patients with a KA-designed femoral component and an insert with a medial ball-in-socket, lateral flat articulation, and PCL retention. Each filled out preoperative and six-week Oxford Knee Score (OKS), Knee Society Score (KSS), Knee Function Score (KFS), and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) questionnaires. The six-week minus preoperative value indicated improvement. RESULTS: between age cohorts, the improvement was not different (p = 0.2319 to 0.9888). The mean improvement/six-week postoperative value was 6°/-2° for knee extension, 0°/119° for knee flexion, 7/31 for the OKS, 39/96 for the KSS, 7/64 for the KFS, and 13/62 for the KOOS. The 30-day hospital readmission rate was 1%. CONCLUSION: surgeons who perform KA TKA can counsel 50 to 89-year-old patients that they can be safely discharged home on the surgery day with a low risk of readmission and can achieve better function at six weeks than preoperatively when performing exercises without a physical therapist.