Influence of Comorbidities on Short-term Functional Outcomes after Unilateral Total Knee Arthroplasty.

Objective To determine the effect of comorbidities on physical function and quality of life (QoL) of patients at 3-months after total knee arthroplasty (TKA). Design Data from 140 patients who underwent a primary unilateral TKA were examined retrospectively. Comorbidities were osteoporosis, presarcopenia, degenerative spine disease, diabetes, and hypertension. All patients completed the following: range of motion (ROM), stair climbing test (SCT), 6-minute walk test (6MWT), timed up-and-go test (TUG), peak torque (PT) of the knee extensor and flexor, instrumental gait analysis, Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and EuroQoL five dimensions (EQ-5D) questionnaire. Results Univariate analyses revealed that osteoporosis led to a significantly longer time to complete the SCT-ascent, SCT-descent, and TUG, and to lower scores for the 6MWT and PT of the knee extensor. Patients with degenerative spine disease showed significant negative scores for knee extension ROM. Diabetes showed a negative correlation with PT of the knee extensor and knee flexion ROM, and a higher WOMAC-stiffness score. Multivariable linear regression analysis showed that WOMAC-stiffness remained independently associated with diabetes. 6MWT, TUG, and SCT-ascent. PT of the knee extensors showed a significant association with osteoporosis. Conclusion Comorbidities, particularly osteoporosis and diabetes, affect short-term functional outcomes 3 months after TKA.