Statin Therapy Associated With Reduced Revision Risk Following Hip, Knee Arthroplasty

The risk for revision surgery in patients who have undergone total hip or knee arthroplasty (THA/TKA) was reduced in patients who initiated statin therapy within 5 years of their original procedure, according to study results published in The Journal of Rheumatology.

Statins, which may affect bone homeostasis and inhibit inflammation, have been proposed as a means of mitigating the risk for and morbidities associated with revision surgery. Investigators aimed to evaluate whether statin exposure timing or duration is related to the risk for THA/TKA revision using an experimental design that differed from prior studies by considering timing relative to the primary surgery.

A retrospective analysis used data from the Clinical Practice Research Datalink, a large UK population-based effort, to enroll participants who underwent THA/TKA between 1988 and 2016. Cox regression analysis with propensity score adjustment was utilized to determine correlations between statin exposure and THA/TKA revision risk, considering the timing of first exposure and the duration of statin therapy.

The primary exposure was post-arthroplasty statin therapy, while the primary outcome was all-cause revision arthroplasty.

A total of 151,305 individuals (mean age, 69.7 years; 59% women; median follow-up, 3.9 years) were analyzed, with 65,032 (43%) patients exposed to statins following primary arthroplasty and 3500 (2.3%) requiring revision surgery. There were 78,594 and 72,711 people who underwent THA and TKA, respectively.

The cohort was divided into patients with statin exposure (n=65,032; mean age, 70.3 years; 53.7% women ) and patients without exposure (n=86,273; mean age, 69.2 years; 62.9% women). There were 852 (1.3%) patients exposed to statins who required revision arthroplasty compared with 2648 (3.1%) unexposed patients who had revision surgery.

After multivariable adjustment, statin exposure was associated with a lower overall revision risk (hazard ratio [HR], 0.82; 95% CI, 0.75-0.90) with joint stratification showing reduced risk for hip (HR, 0.86; 95% CI, 0.76-0.98) and knee (HR, 0.76; 95% CI, 0.66-0.88). In patients exposed to statins <1 year post-surgery compared with patients unexposed to statins, the HR for revision was 0.82 (95% CI, 0.74-0.91) with an E-value of 1.49; patients exposed to statins 1 to 5 years after surgery had a revision HR of 0.76 (95% CI, 0.65-0.90) with an E-value of 1.64, while patients exposed to statins >5 years after primary arthroplasty had an HR of 0.95 (95% CI, 0.76-1.19).

Considering statin therapy duration, compared with individuals with <1 year total exposure, participants with >5 years exposure also demonstrated reduced revision risk (HR, 0.74; 95% CI, 0.62-0.88).

Study strengths included a large sample representative of UK patients with detailed data on prescriptions, morbidity, and demographics. Study limitations included possible residual confounding, lack of information about which side the primary arthroplasty was performed on, and potential misclassification of participants.

“Given the increasing number of THA/TKA carried out globally and the increased costs and poorer clinical outcomes associated with revision surgery, if the results of our study are confirmed, statins may potentially provide an approach to reducing the risk of revision surgery in patients undergoing primary THA/TKA,” noted the investigators. They recommended that future research endeavor to confirm their findings and identify possible mechanisms of action.

Reference

Cook MJ, Sorial AK, Lunt M, Board TN, O’Neill TW. Effect of timing and duration of statin exposure on risk of hip or knee revision arthroplasty: a population-based cohort study [published online March 15, 2019]. J Rheumatol. doi:10.3899/jrheum.180574