There has been a recent trend to treat subcapital hip fractures with total joint replacement, but is this the ideal solution for all patients, especially those with limited life expectancy? Using the Kaiser Healthcare System’s extensive data set, Foster Chen, MD, FAAOS, adult reconstruction specialist at Kaiser Permanente Capitol Hill Medical Center in Seattle, and colleagues reviewed the records of thousands of patients to see whether they could tease out best-practice recommendations for the management of hip fractures, based on patient age and health status. They presented their findings at the AAOS 2024 Annual Meeting. AAOS Now Editorial Board member Stuart A. Green, MD, FAAOS, sat down with Dr. Chen to discuss this study and the clinical takeaways.

Dr. Green: What motivated you to do this study?
Dr. Chen: There’s a lot of controversy in the world of hip fracture treatment. There are three large categories: monopolar and bipolar hemiarthroplasty and total hip arthroplasty. Which surgery is the best, for what kind of a patient? With hemiarthroplasty options, there’s a shorter surgery, yet you have to worry about acetabular erosion. On the flip side, [in total hip arthroplasty,] you have better function, especially in younger patients, yet they also come with more complications, [such as] dislocations.

So, you ask the question, which one might be better or more appropriate? These patients are sick to begin with, with a quarter to a fifth chance of mortality in the next year. If you die before ever needing a revision, you can say that might have been the appropriate surgery in the first place. You may not live long enough to realize the advantages or drawbacks of either option. Within that backdrop, our Australian colleagues published on their registry data that bipolars had a little bit of a survivorship advantage compared to monopolars. [Our study] was a Kaiser Permanente registry study. Kaiser is a pretty large system with eight geographic regions, although for the hip fracture registry, we incorporate data from California, Oregon, and Hawaii. We use the registry to track how patients who have one of these three surgeries [performed] over time.

So basically, it was a retrospective review?
It was a retrospective review within our large registry.

What were your conclusions?
First of all, we found that there is a bit of a survivorship advantage of total hip arthroplasty over hemiarthroplasty of both types. But the differences really started to diverge once you looked at the young cohorts and the lower [American Society of Anesthesiologists (ASA) classification] of 1 to 2. We intentionally excluded ASA 4 and above as that would be a strong driver for hemiarthroplasty. We also excluded individuals [aged] less than 60, strong drivers [of] a total hip arthroplasty, to really get down into this gray area of in-betweens, where any provider might say: “We’re not really sure which direction to go.”

If you looked at the 60- to 79-year-old individuals, their survivorship with a total hip arthroplasty was significantly better than a unipolar or a monopolar. Unipolars did the worst compared to the other two cohorts. Bipolars occupied an intermediate position. When looked at from the ASA perspective, we divided the ASA of 1 to 2 versus 3, and a similar thing happened: [For] those who are sicker, it didn’t make much of a difference, but on the ASA of 1 to 2, unipolars did the worst, bipolars did somewhere in between, and then total arthroplasty had the fewest revisions, taking into account mortality. But, once you get to ASA of 3, or age 80 or over, the survivorship differentials seem to wash away. It doesn’t seem to make much of a difference (in terms of revisions) which surgery you end up getting.

That makes a lot of sense, if you think about what influences the way surgeons understand the situation: If you have an older patient, why risk the possibility of a total hip replacement 5 years down the line because of cartilage wear on the acetabular side when they’re not going to live that long. Your study, using big data, is helpful. A lot of data have been coming out of the Kaiser hip group.
Our sample size in this study for hip fractures was 14,000 individuals. So, surgeons inherently understand this pattern. Our smallest group was, in fact, individuals greater than 80 undergoing a total hip; only a couple of hundred of them. So, surgeons are practicing with that knowledge in the background.

Stuart A. Green, MD, FAAOS, is cofounder and past president of the Limb Lengthening and Reconstruction Society; past president of the Association of Bone and Joint Surgeons; and an attending surgeon at the Tibor Rubin Long Beach VA Medical Center. He is the son, first cousin, and father of AAOS Fellows. Dr. Green is a member of the AAOS Now Editorial Board.