Dr. Hsu talks about a common knee problem

Learn how internal derangement of the knee can affect you.

May 22, 2020


Orthopedic sports medicine physician Dr. Jim Hsu was recently featured on KOMO radio’s Health Talk. He talked about internal derangement of the knee with Shannon O’Kelley, president of IRG Physical & Hand Therapy. 



Expert insights


Internal derangement of the knee is a general term for a condition that keeps your knee from working normally. It can be due to overuse, aging or a more serious injury, like a tear. Symptoms can include swelling, instability, and a catching or clicking feeling. 

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Shannon O’Kelley: Dr. Hsu, welcome to Health Talk. How are you today?

Dr. Jim Hsu: I’m doing great, thank you.

Shannon O’Kelley: Well, thank you for joining us. We’re gonna talk about internal derangement, kind of these knee problems, but before we start talking about internal derangement, a problem of the knee, tell our listeners about your practice, your area of interest, how you got started in orthopedics and take us back. Take us into a day in the life of Dr. Hsu, huh?

Dr. Jim Hsu: Yeah, so I belong to a speciality called orthopedic surgery where we treat the moving parts of the body. Muscles, tendons, bones, cartilage, ligaments, and I got interested in it because I’ve always wanted to be an athlete but have not had the chance to because I study the violin [laughs] and my parents did not want me out there injuring myself. So, however, I really took an interest to wanting to help people get better and get more active and so during my residency in orthopedic surgery, I developed an interest in orthopedic sports medicine where we see a lot of injuries that come from sports, obviously, but also from people who have regular injuries, such as work injuries and uh bike accidents and such.

Shannon O’Kelley: So when you’re talking about sports medicine, I mean sports medicine encompasses a lot of different - in our world sports medicine is people that work, at work they’re athletes, they’re at-work athletes and they can injure their shoulders and knees, and that’s the area you focus in, is a lot of interest in extremities in sports medicine problems.

Dr. Jim Hsu: Exactly, yeah. So the common injuries in sports medicine would be, for example, ligament injuries. We’ve all heard of them, such as ACL tears, and also rotator cuff tears of the shoulder, and meniscus tears and such. So those are the types of conditions that I typically treat, and also, the sports medicine field is very much in the forefront of treating things through minimally invasive techniques. Like with an arthroscope, we can treat, repair, reconstruct multiple soft tissue injuries through very, very small incisions, and usually that leads to faster recovery.

Shannon O’Kelley: It’s amazing. Some of the technology that I’ve seen over the last 30 years is really impressive, and you talk about minimally invasive procedures through the scope, and then you talk about recovery from a physical therapy standpoint, it’s phenomenal. I mean, there is a lot less tissue disruption, a lot less disruption of the tissue during surgery so recovery is faster, but it does take biological time to heal tissue, so there is some restrictions just with body healing.

Dr. Jim Hsu: Right, I think that you’re exactly right that the principles of healing of the things that you’re repairing are still the same. It still takes care and attention and precautions, and I’m a big believer in physical therapy so I usually will rely upon um physical therapy colleagues to help guide the patient through the months of rehab that is sometimes necessary. However, the minimally invasive techniques does do allow the patients to overcome the initial pain, and less incision and less exposure usually means not just less pain, but also less risk for complications, and people usually get back on their feet for basic activities a lot faster.

Shannon O’Kelley: Right, let’s talk about the knee. Let’s talk about what we’re here to talk about today, is what we term “internal derangement.” And I’m gonna set this up with a conversation that I just had last week with a friend of mine who is an active skier, and last year during skiing, he tweaked his knee. That’s how he described it. He called me up the other day and said, “You know, last year I was skiing, I tweaked my knee, and it just hasn’t really been the same.” I said, “What are your symptoms? What’s going on?” You know, he’s got a little clicking and popping, he gets a little swelling. He kinda feels a little unstable or instability when he plants and rotates on that, kind of a sensation of locking or buckling. So I said, “Oh, you know, you better have that looked at. You may have what we describe an internal derangement.” So I’m gonna let you tell our listeners as we start here, and we have a little bit of time left, but let’s start with internal derangement. What is it?

Dr. Jim Hsu: Internal derangement of the knee refers to conditions that are abnormal within the knee joint. This is different from other conditions like referred pain or sciatica where pain is felt in the knee but is actually coming from elsewhere.

Narrator: We’re talking about internal knee derangement. We’ll continue that conversation with Dr. Jim Hsu, orthopedic surgeon for The Polyclinic, and Shannon O’Kelly, coming up right after this time out on KOMO.

Shannon O’Kelley: Dr. Hsu, again, thank you for joining us here on Health Talk and thank you for sharing your knowledge regarding internal derangement. We were talking about an internal derangement which can be a number of different things in the knee. Maybe you can define what internal derangement can be, because it’s a global termed kind in the knee.

Dr. Jim Hsu: Right, so it usually refers to conditions that actually physically reside within the knee. I know that that sounds very simple, but it is actually sometimes hard to define because a lot of times we can feel pain in the knee but it’s because of other areas being not as strong, like hip abductors or hamstrings or even sometimes sciatica from back conditions. So once there are enough hints, then often the orthopedic surgeon will determine that the most likely cause for knee pain is internal derangement, which can range from something benign like a temporary swelling of soft tissue, maybe from over use but that just feels painful because usually everything fits very well within the knee and it gets caught or gets pinched. However, there are also other more concerning and sometimes physically irreversible conditions, like meniscus tears or ACL tears, and those can present with the symptoms your friend was mentioning, such as swelling, instability, sudden buckling, and catching and clicking.

Shannon O’Kelley: Well, that’s what I told my friend. I said, “You probably need to get this looked at, and get it looked at early in the season if you wanna get to skiing.” Snow’s falling out there, mountains are opening, and he needs to get in there and get that looked at because you are gonna take a look at that knee and make an assessment. How do you do that when someone presents to your office?

Dr. Jim Hsu: Usually it starts with a thorough history. I usually like to find out how the pain starts, whether it starts suddenly, unexpectedly, or it kind of crept up on him, and those can mean different things ranging from actual tears that are unstable and unpredictable, to sometimes it is a degenerative process that builds and sneaks up on him. And then also a physical exam is very important, where I check general conditions such as range, motion, strength, alignment, whether there is any fluid in the joint, and then also specific exams depending on my suspicion whether or not there is any sign for a meniscus condition and ligament tears and instability. And then of course we’ll base further testing on those findings.

Shannon O’Kelley: Yeah, you’re gonna get so much information from what you just described. In our world of medicine, it’s called a history and physical. So then you have suspicion, you might order a test. But if you do have to scope this knee, let’s say it’s a meniscus, it’s a pretty - I don’t want to use the word “simple,” but it’s a simpler or easier procedure in today’s world than it was 30 years ago.

Dr. Jim Hsu: Yes it is. Previously, we used to make large incisions, and we’re limited by what we can see even with a large incision. But these days, with very small stab incisions, we can see pretty much everything inside the knee.

Shannon O’Kelley: Well, Dr. Hsu, again, I’m sorry but we’re out of time, and your information was fantastic, and I’m gonna tell my friend there’s hope, right? [laughs]

Dr. Jim Hsu: Yes, there definitely is.

Shannon O’Kelley: Thank you so much for your time. 

Dr. Jim Hsu: My pleasure. Thank you.


Diagnosis and treatment

Dr. Hsu starts with a thorough medical history, which includes finding out how the pain started. He then does a physical exam to look at range of motion, strength, alignment and to check for fluid in the knee. Further testing is done, if needed.

When surgery is needed, Dr. Hsu uses minimally invasive techniques. Smaller incisions mean less damage to the body, fewer complications and faster recovery. Dr. Hsu also believes physical therapy is key to helping patients through the recovery process.

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The information provided is for general informational purposes only and is not intended to be medical advice or a substitute for professional health care. You should consult an appropriate health care professional for your specific needs.