Changes in rates of arthroscopy due to degenerative knee disease and traumatic meniscal tears in Finland and Sweden

Background and purpose — Knee arthroscopy is commonly per-formed to treat degenerative knee disease symptoms and trau-matic meniscal tears. We evaluated whether the recent high-qual-ity randomized control trials not favoring arthroscopic surgery for degenerative knee disease affected the procedure incidence and trends in Finland and Sweden. Patients and methods — We conducted a bi-national registry-based study including all adult (aged ≥18 years) inpatient and out-patient arthroscopic surgeries performed for degenerative knee disease (osteoarthritis (OA) and degenerative meniscal tears) and traumatic meniscal tears in Finland between 1997 and 2012, and in Sweden between 2001 and 2012. Results — In Finland, the annual number of operations was 16,389 in 1997, reached 20,432 in 2007, and declined to 15,018 in 2012. In Sweden, the number of operations was 9,944 in 2001, reached 11,711 in 2008, and declined to 8,114 in 2012. The knee arthroscopy incidence for OA was 124 per 105 person-years in 2012 in Finland and it was 51 in Sweden. The incidence of knee arthroscopies for meniscal tears coded as traumatic steadily increased in Finland from 64 per 105 person-years in 1997 to 97 per 105 person-years in 2012, but not in Sweden.Interpretation — The incidence of arthroscopies for degenera-tive knee disease declined after 2008 in both countries. Remark-ably, the incidence of arthroscopy for degenerative knee disease and traumatic meniscal tears is 2 to 4 times higher in Finland than in Sweden. Efficient implementation of new high-quality evi-dence in clinical practice could reduce the number of ineffective surgeries.