- Design
- Nationwide propensity-matched cohort, South Korea
- Population
- 20,707 matched pairs with and without Parkinson disease having unilateral knee replacement
- Primary outcome
- Five-year vascular events, periprosthetic fracture and joint infection
- Effect
- Cerebrovascular events HR 1.11 (95% CI 1.07 to 1.16); no difference in fracture or infection
Using South Korea's national insurance database, researchers matched 20,707 people with Parkinson disease diagnosed before unilateral knee replacement to people without it, excluding anyone with prior cardiovascular or cerebrovascular disease, and followed them for five years.
Parkinson disease was associated with a slightly higher hazard of cerebrovascular events (adjusted HR 1.11, 95% CI 1.07 to 1.16) but not cardiovascular events, periprosthetic fracture or periprosthetic joint infection. In those diagnosed within five years before surgery, both cerebrovascular (HR 1.14) and cardiovascular events (HR 1.05) were slightly higher; in those diagnosed longer before, neither was.
The authors are explicit that this does not justify routine vascular screening because a patient has Parkinson disease. The reassuring finding for surgeons is that fracture and infection risk were not higher.
- Reassure patients with Parkinson disease that this cohort found no excess periprosthetic infection or fracture after knee replacement.
- Review blood pressure stability and autonomic symptoms before surgery in patients with Parkinson disease.
- Plan perioperative Parkinson medication timing with the neurology or medical team to avoid missed doses.
- Do not order vascular screening solely because the patient has Parkinson disease.
Why it matters
Surgeons often hesitate over knee replacement in Parkinson disease because of feared fracture and infection, which this cohort did not show.
Don't overread it
The vascular hazard ratios are small and come from administrative codes without measures of disease severity.
The statistics, in plain English
A hazard ratio of 1.11 means the rate of cerebrovascular events was about 11% higher — a small relative difference. Because the database lacked Parkinson severity and frailty, some of the difference may reflect those rather than the diagnosis.
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