Parkinson disease before knee replacement: a small rise in cerebrovascular events, not in infection

Design

Nationwide retrospective cohort with propensity-score matching (South Korea)

Population

20,728 patients with Parkinson disease and 287,075 without, all with unilateral TKA and at least 5 years of follow-up

Primary outcome

5-year vascular events, periprosthetic fracture and joint infection

Effect

Cerebrovascular events adjusted HR 1.11 (95% CI 1.07 to 1.16); no increase in fracture or infection

This Korean national insurance database study identified patients who had a unilateral knee replacement between 2010 and 2018 and had at least five years of follow-up. It excluded people with prior cardiovascular or cerebrovascular disease. The unmatched cohort held 287,075 patients without Parkinson disease and 20,728 with Parkinson disease diagnosed before surgery (16,877 diagnosed within five years, 3,851 more than five years before). Each Parkinson group was propensity-matched 1:1 to patients without it.

After adjustment, Parkinson disease was associated with a slightly higher five-year hazard of cerebrovascular events (adjusted HR 1.11, 95% CI 1.07 to 1.16), but not with cardiovascular events overall, periprosthetic fracture or periprosthetic joint infection. In those diagnosed within five years of surgery, cardiovascular (HR 1.05, 1.01 to 1.10) and cerebrovascular (HR 1.14, 1.09 to 1.18) hazards were slightly higher; this was not seen when diagnosis was more than five years before surgery.

The authors say the findings do not support routine vascular screening just because a patient has Parkinson disease. Disease severity and frailty were not captured, so the associations may partly reflect them.

• Parkinson disease was linked to a small rise in 5-year cerebrovascular events (HR 1.11).
• Periprosthetic fracture and joint infection were not higher.
• The extra risk was seen mainly when diagnosis was within 5 years of surgery.
• The authors do not support routine vascular screening on this basis alone.
• Consider multidisciplinary review of blood pressure, autonomic symptoms and medication timing in selected patients.

Why it matters

It gives a reassuring answer on infection and fracture while flagging where to concentrate perioperative medical input.

Don't overread it

This is an insurance database study without disease severity, so it shows associations only.

The statistics, in plain English

A hazard ratio of 1.11 means about 11% higher rate of events at any time over five years in the Parkinson group; with very large numbers even small differences reach significance, so the size matters more than the p value. Matching balances measured factors but not Parkinson severity.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.