High-volume surgeons may yield improved UKA survivorship vs. lower-volume surgeons
Click Here to Manage Email Alerts
Key takeaways:
- Unicompartmental knee arthroplasty performed by high-volume surgeons was associated with improved survivorship rates at 5 years.
- Survivorship rates were compared for high-, medium- and low-volume surgeons.
Compared with lower-volume surgeons, high-volume surgeons had improved 5-year survivorship rates for unicompartmental knee arthroplasty despite being more likely to operate on older Medicare patients, according to published results.
Using the Michigan Arthroplasty Registry Collaborative Quality Initiative, Muhammad J. Abbas, MD, a resident in the department of orthopedic surgery at Henry Ford Hospital in Detroit, and colleagues performed a retrospective review of data from 15,542 UKAs that were performed by 287 surgeons between February 2012 and November 2021.
Overall, 14 surgeons (4.9%) were classified as high volume, 36 surgeons (12.5%) were classified as medium volume and 237 surgeons (82.6%) were classified as low volume. According to the study, high-volume surgeons performed 35 or more UKAs per year, while medium-volume surgeons performed 15 to 34 UKAs per year and low-volume surgeons performed fewer than 15 UKAs per year.
Abbas and colleagues found 4.5% of all UKAs (n = 701) were revised within 5 years, with 58.8% of all revisions (n = 412) occurring within 2 years after initial surgery. They found high-volume, medium-volume and low-volume surgeons had 5-year revision rates of 4.3%, 5.2% and 7.2%, respectively. They noted the 5-year revision rate for TKAs from the same registry was 3%. Abbas and colleagues also noted high-volume surgeons were more likely to operate on older patients, Medicare patients and patients with higher American Society of Anesthesiologists scores.
“It stands to reason that surgeons who perform UKA more frequently have improved implant survivorship when compared to their low-volume counterparts,” Abbas and colleagues wrote in the study.
Perspective
Back to Top
Unicompartmental knee arthroplasty remains the preferred surgical option for patients with arthritic disease limited to one compartment. However, utilization rates remain low in part due to its technically challenging nature. Indeed, studies have shown that subtle malalignment in the coronal or sagittal planes can predispose to mechanical failure or progression of arthritis in the adjacent compartment. Presumably, low-volume surgeons would be less familiar with the technical aspects of this procedure.
While the results of Muhammad J. Abbas, MD, and colleagues are not novel, it helps to reinforce the sobering finding of lower survivorship following UKA compared to total knee arthroplasty, even among high-volume surgeons. Furthermore, as the authors rightly pointed out, the higher revision rates when UKA was performed by low-volume surgeons is a finding that has been echoed by previous registry studies outside North America. However, an inherent weakness of any registry is the lack of radiographic analysis, and one can only assume that this is attributable to a higher rate of technical errors such as component malpositioning or malsizing. Nonetheless, the authors make this assertion a compelling one by describing the breakdown of surgeons who had early revisions within 2 years: 73% were low-volume surgeons, while only 8.8% were high-volume surgeons.
Another plausible reason could be the lack of familiarity with indication criteria, which have evolved dramatically during the past decade. This then begs the question: What defines a low-volume surgeon? The general consensus based on the literature seems to vary between 10 to 15 cases per year, although the exact number remains difficult to determine but is likely clinically irrelevant. Finally, if physicians are taught to “first, do no harm,” orthopedic practices need to decide: Should low-volume surgeons be allowed to offer UKA instead of TKA? This question remains difficult to answer. For surgeons who struggle to increase their UKA case volume, it is possible that robotic technology may present an interesting solution as it has been shown to optimize alignment and positioning in a consistent and reliable manner, although evidence surrounding this exact topic remains lacking.
Before definitive recommendations can be made, future research should directly compare the outcomes and survivorship of UKA performed by low-volume surgeons with robotic assistance vs. high-volume surgeons using manual instrumentation.
References:
Collier MB, et al. J Arthroplasty. 2006;doi:10.1016/j.arth.2006.04.012.
Hamilton TW, et al. J Arthroplasty. 2017;doi:10.1016/j.arth.2017.04.063.
Hernigou P, et al. J Bone Joint Surg Am. 2004;doi:10.2106/00004623-200403000-00007.
Liddle AD, et al. J Bont Joint Surg Am. 2016;doi:10.2106/jbjs.n.00487.
Lonner JH, et al. Int Orthop. 2023;doi:10.1007/s00264-022-05411-3.
Mohammad HR, et al. J Bone Joint Surg Am. 2020;doi:10.2106/JBJS.19.01060.
Vasso M, et al. EFORT Open Rev. 2018;doi:10.1302/2058-5241.3.170060.
Collapse
Read more about
Click Here to Manage Email Alerts