For total hip arthroplasty success, is there a magic number for a surgeon to surpass? According to researchers from University of Toronto and Women’s College Hospital, both in Toronto, Canada, that number is 35. The researchers found that patients whose surgeons had performed ≤ 35 such procedures in the year before had a 48% higher risk of dislocation and 44% higher risk of early revision.
The analysis covered 37,881 people who received their first primary total hip arthroplasty during 2002 to 2009 and were followed for ≥ 2 years after surgery. Researchers found that the main outcomes included surgical complications, such as venous thromboembolism, death within 90 days, and infection. Other complications included dislocation, periprosthetic fracture, and revision within 2 years. The procedures were performed by 350 surgeons, with 19 years median experience and a median annual volume of 55 procedures.
As the surgeon’s yearly volume of hip arthroplasty procedures rose, the researchers saw a “noticeable decrease” in likelihood of dislocation and revision, but the relation was not linear. Surgeons with extremely low volumes had predicted rates of dislocation of about 4%, with a drop in likelihood to about 2% at 25 to 50 procedures a year. After that point, the relative improvement in complication rates in relation to volume attenuated, but the trend of decreasing risk continued downward. That trend indicates that increased surgeon volume continues to have a beneficial impact, albeit less pronounced, the researchers conclude.
The effects on thromboembolism, death, infection, and periprosthetic fracture did not show an obvious association between surgeon volume and risk of complication. That conclusion is consistent with the current knowledge about the risk factors for those complications, which have more to do with patient factors, such as gender and frailty, the researchers say.
The researchers also note that their novel method of using a spline to visually describe the relationship between surgeon volume and complications allowed them to select a cut point with “more confidence than in previous studies.” That method, they believe, could be applied easily to other procedures to optimize health care delivery.
Source
Ravi B, Jenkinson R, Austin PC, et al. BMJ. 2014;348:g3284.
doi: 10.1136/bmj.g3284.