Prevalence and impact of preoperative osteoporosis on healthcare utilization and patient-reported outcomes in primary total knee arthroplasty.

PURPOSE: Osteoporosis is a well-recognized risk factor for complications after total knee arthroplasty (TKA). However, the effect of pre-TKA osteoporosis on healthcare utilization and patient-reported outcomes is poorly understood. Here, we characterize the association between pre-TKA osteoporosis and (1) healthcare utilization and patient-reported pain and function outcome measures; and (2) dual X-ray absorptiometry (DEXA) scan T-scores and the aforementioned outcomes.

METHODS

A prospective cohort of primary elective TKA patients between July 2015 and January 2020 was obtained (n = 6318), of which 4922 (77.9%) completed 1-year follow-up. Outcomes included healthcare utilization (prolonged length of stay (LOS) ≥ 3D, discharge disposition (DD), 90-day readmission, and 1-year reoperation) as well as Knee Injury and Osteoarthritis Outcome Score (KOOS) Pain, KOOS-function (PS) and satisfaction.

RESULTS

The prevalence of pre-TKA osteoporosis was 66.8%, of which 28.7% had a DEXA scan and 66.3% were on osteoporosis medications. Medicated osteoporotic patients were independently associated with higher odds of prolonged LOS (Odds Ratio (OR): 1.21 (95% Confidence Interval (CI) 1.02-1.43)) and non-home DD (OR:1.56 (95%CI 1.25-1.95)). Medicated and non-medicated osteoporosis patients were associated with higher odds of 90-day readmission. The odds of failing to achieve MCID or satisfaction were not associated with preoperative OP diagnosis.

CONCLUSION

Two-thirds of primary TKA recipients had osteoporosis. Among these patients, two-thirds were on medication and one-third had a DEXA scan. Osteoporotic patients are at a higher risk of 90-day hospital readmission, longer hospital stays and non-home discharge. Interestingly, osteoporosis status was not associated with failure to achieve clinically significant improvements or satisfaction at 1 year following TKA.