Spine surgery trends show that a greater proportion of spine surgeries are moving to an outpatient hospital setting, but fewer are moving to ASCs, according to a new study.

  • Spine surgery typically does not feature a safety profile that works with a same-day admission and discharge.
  • Also, many spine surgeons tend to prefer outpatient surgery at medical centers, where there is the capacity for prolonged monitoring.
  • Some surgeons believe that a minority of spine surgeries can be performed at ASCs when they involve otherwise healthy patients who present with minimal risk factors.

The healthcare industry’s focus on greater efficiency and cost-effectiveness is moving more surgeries to the outpatient setting, including spine and joint replacement procedures. But what, exactly, is the trend for surgeries that previously required several-day hospitalizations?

Researchers studied spine surgery trends to see how often spine surgery is performed in an outpatient hospital setting vs. a true ambulatory setting. They found that a greater proportion of spine surgeries are moving to the outpatient hospital setting, but not quite as many are moving to ASCs.1

“The reason we did this study was, in the recent past, as we get more efficient with healthcare and more cost-effective, we are naturally moving more toward an outpatient model for a lot of procedures, decreasing length of stay, and we’ve seen this trend in spine surgery and joint replacement surgery,” says Michael J. Lee, MD, associate professor of orthopaedic surgery and co-director of the Operative Performance Research Institute at the University of Chicago Medical Center.

Outpatient surgeries can vary according to the setting and state regulations. The term can be used to connote same-day admission and discharge, or it can refer to surgery and discharge that take place within a 23-hour window, allowing for a longer observation period, Lee says.

Although most outpatient surgeries feature safety profiles that work with a same-day admission and discharge, spine surgeries typically do not, he explains.

“Post-surgical hematomas for many surgeries can cause pain and wound healing difficulty,” Lee adds. “However, after spine surgery, post-operative hematomas, if not identified and treated in a timely fashion, can literally cause paralysis and airway obstruction.”

So, many spine surgeons prefer outpatient surgery at medical centers, where there is the capacity for prolonged monitoring, if needed. They can convert a patient’s status to inpatient without much difficulty in that setting, he says.

“But if I do the surgery at an ASC and the patients need to be monitored beyond 23 hours, the patient needs to be physically transferred to an inpatient facility,” Lee says.

Many ASCs can handle 23-hour observation periods, but this practice is limited by state regulations. For example, six states define ASCs as requiring discharge on the same calendar day of admission and not as a 23-hour stay, Lee explains.

“So, in this study, we looked at states that defined ASC as the same calendar day discharge to see whether rates of outpatient spine surgery were the same as for outpatient spine surgery elsewhere,” Lee says. “We found that the rates for ASCs were way below the rates for outpatient spine surgery at non-ASCs.”

This difference could reflect the fact that there aren’t as many ASCs in the same-day surgery center states, but researchers interpreted the data differently. “We suspect that because of complications unique to spine surgery, most spine surgeons prefer to perform their outpatient surgery at facilities with capacity for prolonged monitoring, if needed,” Lee says.

In states in which ASCs are not defined as same-day surgery, there were two-to-seven times greater rates of spine surgery at ASCs than in the other states, he adds.

“We’re seeing a push where some surgeons may perform surgeries at a facility where they can stay for 23 hours,” Lee says. “The majority of time, it will probably work out, but if you require that patients be discharged the same calendar day as admission — I suspect that is a threshold of risk that most spine surgeons may not be willing to assume.”

Spine surgeries moving to outpatient surgical settings include microdiscectomy, which is performed for a herniated disc; lumbar laminectomy surgery for spinal stenosis, which is performed to alleviate pain from neural impingement; and anterior cervical discectomy and fusion, which is a type of neck surgery that removes a damaged disc, Lee explains.

“These are surgeries that increasingly fall within the parameter of outpatient surgery,” he says. “The question among spine surgeons is whether they can be done safely at true [ASCs], and should they be done there.”

There is a growing belief that these types of surgeries can be performed at ASCs when they involve otherwise healthy patients who present with minimal risk factors. “But a very small minority of cases are being done at true ASCs,” he says.

“In the course of achieving optimal cost-effectiveness, we can’t lose sight of patient safety,” Lee cautions. “That threshold for complications for surgeries at ASCs has not been defined in our industry.”

The emphasis always must be on patient safety, Lee adds.


  1. Idowu OA, Boyajian HH, Ramos E, et al. Trend of spine surgeries in the outpatient hospital setting vs. ambulatory surgical center. Spine 2017 Mar 31. doi: 10.1097/BRS.0000000000002180. [Epub ahead of print].