Looking for damage with a needle in a knee joint    

Needle arthroscopy, used at UCHealth for the first time in the Rocky Mountain region, allows some patients to get a diagnosis of knee problems without general anesthesia.
October 26th, 2020
Meghan at her wedding. Needle arthroscopy made it possible for her to get a quick diagnosis fo her knee pain.
Meghan McKenna hurt her left knee during a high-intensity workout before her January wedding. A new, minimally invasive needle arthroscopy made it easy for her doctor to immediately diagnose the problem. Photo courtesy of Gesina Null, gesinamariephotography.com.

Meghan McKenna was working hard late last year to get ready for her wedding, but her left knee had an objection.

To get ready for the January 2020 date, McKenna, 32, says she began a series of high-intensity workouts. She didn’t anticipate a problem; yoga, barre exercises, and walking were regulars in her routine. But that knee had other ideas.

In the midst of her workouts, the joint began to buckle and swell. The more McKenna moved, the balkier the knee became.

“If I exercised, ran walked or jumped, I was in a ton of trouble,” she said.

McKenna nonetheless stuck to her plan and got married January 4, bad knee and all. But despite physical therapy and rest, the pain persisted. It turned out it was cartilage damage and a bone bruise and cyst in the upper part of her femur, or thighbone. Her orthopedist recommended repairing the damage with an autograft: bone and cartilage transplanted from a non-weight-bearing part of her body. That was a daunting prospect when she considered the size of her knee injury.

A second look using a needle arthroscopy

Dr. Rachel Frank uses needle arthroscopy to diagnose patients' knee problems.
Dr. Rachel Frank.

The uncertainty led McKenna to seek a second opinion from Dr. Rachel Frank, an orthopedic surgeon and associate professor of Orthopedics with the University of Colorado School of Medicine. Frank is director of CU’s Joint Preservation Program  and practices at UCHealth CU Sports Medicine, UCHealth Steadman Hawkins Clinic Denver, and the UCHealth Orthopedics Clinic on the Anschutz Medical Campus.

Frank needed to assess the extent of McKenna’s joint damage before she could recommend a path to repair it. That would typically require an arthroscopy – a minimally invasive surgery to peer inside the joint with a camera mounted on a thin tube – under general anesthesia. Frank offered McKenna an alternative, one that she was the first to perform in Colorado and the Rocky Mountain region.

The new technology is based on needle arthroscopy, a technique that uses instruments that are 2 millimeters in diameter – about one-half the size of those traditionally used in the procedure to examine the joint. In this case, Dr. Frank used a needle arthroscopy system called the NanoScope.

More minimal than minimal

The miniature instruments require only local anesthesia and tiny poke holes to enter the joint. If Frank encountered no problems, McKenna could complete the whole procedure in the office in about 20 minutes, avoid anesthesia, walk out under her own power and, most importantly, get a diagnosis and recommendation for care that day rather than after recovering from surgery.

Frank, who has now been using the NanoScope for nearly a year, emphasized that the system does not replace traditional arthroscopy. It does, however, expand the care she can offer patients.

“It’s changed my ability to give my patients answers in a very timely fashion – at the point of care, essentially,” Frank said. “It’s truly the definition of a minimally invasive approach.”

Weighing alternatives

Meghan McKenna poses in Iceland. She benefited from a needle arthroscopy to get a quick diagnosis of her knee problem without needing general anesthesia.
Meghan McKenna on a hike in Iceland. She hopes to get back to normal activity after a cartilage and bone transplant in her left knee that was aided by a diagnosis with a new minimally invasive procedure called needle arthroscopy. Photo courtesy of Meghan McKenna.

The decision about how to proceed, of course, lay with McKenna. She said Frank presented the potential benefits of needle arthroscopy, but urged her to take the time to think it over and discuss it with her husband. McKenna went home, did some research, including watching a video of the NanoScope procedure and opted for it, figuring if it didn’t work she could always have a standard arthroscopy.

“This was going to be my first surgery ever, and I felt like if I could avoid going under [anesthesia], that sounded great to me,” McKenna said. With general anesthesia seemingly unavoidable for a subsequent surgery, the NanoScope procedure “could cut the risk in half,” she added.

In late June, McKenna, admittedly nervous, arrived at Frank’s office for the procedure. Her husband wasn’t available, so her mother stood in for support. Frank, physician assistant Kevin Shinsako and a technician were on hand, masked. After applying a numbing solution to the skin, Frank injected an anesthetic into the joint, then inserted the slender NanoScope through a cannula and into the joint from the outside of McKenna’s knee. Without pain, McKenna watched on a screen as Frank maneuvered the camera-fitted probe about and described the joint problems that she found.

During the procedure, Frank said she identified and measured the defect in McKenna’s cartilage and bone and confirmed there was no additional damage.

On to transplant

“These diagnostic findings, combined with her MRI, allowed me to make an accurate, point-of-care, diagnosis and proceed quickly to the next step,” Frank said. With that, she ordered a donor bone and cartilage graft that she would use as a custom-fit repair for McKenna’s injury.

The cartilage transplant took place at UCHealth Inverness Orthopedics and Spine Surgery Center on July 21. By mid-September McKenna could walk without crutches. She manages her physical therapy at UCHealth CU Sports Medicine and says she is slowly increasing her activity with relatively little pain while she works from home. She missed only a week from her job as a mechanical engineer.

Interviewed in early October, McKenna said she knows she has about six months of work ahead of her to get back to normal levels of activity. Today, climbing stairs is a challenge – she goes up with her right leg only – but she anticipates conquering that climb with patient effort.

“I’m working toward a day or week without thinking about the knee at all,” McKenna said.

The future for new technology

As for the NanoScope decision, “It was kind of a no-brainer,” she said. “Avoiding another surgery was a great decision. Two days later I was mowing the lawn with no pain.”

Frank, meanwhile, sees plenty of promise for the technology, but she wants solid support for it. She’s launched a pilot study to determine if needle arthroscopy could potentially offer a more cost-efficient approach to traditional arthroscopy by reducing OR and recovery time and the need for anesthesia, for example.

The study is necessary to definitively answers those questions, but Frank said her experience makes her optimistic about the future of this technology. In mid-September, she used it for the first time to perform not only a diagnostic procedure but also to shave frayed cartilage from a patient’s knee joint – all under local anesthesia only.

“I see the technology improving to where we can use needle arthroscopy and nano-instrumentation to perform entire procedures or to augment procedures when standard arthroscopic instrumentation is still needed,” she said. “I see the technology allowing us to do more with less pain, and thus less – or even no – narcotic use post-procedure.”

A new option, not a replacement

Still, Frank emphasized that needle arthroscopy is not for everyone. An important part of the pilot study, she said, will be improving identification of ideal candidates. For example, some people may simply prefer traditional surgery under general anesthesia. Others will not tolerate the pain of the office-based injection and subsequent procedure well. Patients with excessive scar tissue or bleeding will require traditional arthroscopies under general anesthesia. And at least for now, so will those who need cleanup of large pieces of frayed cartilage or meniscus tissue, Frank said.

Meghan McKenna is grateful for the NanoScope option and for Frank’s technical expertise. But she added that Frank, who has undergone cartilage transplants and other surgeries for injuries herself, offers more than medical advice.

“Dr. Frank knows how to talk to a patient like a patient,” McKenna said. “She gave me enough time to ask all my questions. I couldn’t be happier.”

About the author

Tyler Smith has been a health care writer, with a focus on hospitals, since 1996. He served as a writer and editor for the Marketing and Communications team at University of Colorado Hospital and UCHealth from 2007 to 2017. More recently, he has reported for and contributed stories to the University of Colorado School of Medicine, the Colorado School of Public Health and the Colorado Bioscience Association.