I want to give a holistic and broad view of how hip mobility plays into important topics in sports medicine.
A study done at the Hospital for Special Surgery, where I did my fellowship, found that athletes who had restrictions in their hip mobility had a higher risk for injury of their ACL. The ACL is a critical ligament that stabilizes the knee.
We frequently think about injuries like ACL tears, but we don’t always think about the reasons for the tear. As this study shows, poor mobility of the hip can lead to excess force and abnormal force in how someone moves. When an athlete is doing the high-level cutting and pivoting activity that is so critical for sports, they’re putting the rest of their joints at risk. ACL tears, meniscus tears and PCL tears can all be caused by poor overall mobility and joint health.
Joint health of the hip helps to control the rest of the body. Neuromuscular control, or how well your muscles can protect your joints, is another consideration. Are your muscles strong enough to protect your joints for the activity that you are doing? The epidemic of knee injuries may potentially be caused by these other joint issues.
Anatomy of the Hip
When you put your hands on your hip, you’re usually pointing at your iliac crest. To an orthopedic surgeon, your hip joint is the ball and socket deep inside the joint. The ball and socket are surrounded by the labrum, a special ring that helps hold the joint in place. The joint is made up of the acetabulum, or socket, and the femoral head, or ball, which comes off the femur (thigh) bone.
Where Hip Pain is Located
Intra-articular hip pain is pain within the hip joint; extra-articular hip pain is pain outside of the hip joint.
When pain is located in the hip joint, it usually feels like it’s down in the groin and usually hurts with rotation and flexion of the hip. Hip injuries are often misdiagnosed as injuries to other things near the hip such as hip flexor injuries or groin injuries. A doctor can move the leg in a FADIR maneuver to bring the hip joint into flexion and internal rotation. If someone with hip pain is having pain from their hip joint ball and socket, this maneuver typically hurts them in that location. Having a positive FADIR, or having pain when a doctor does this maneuver, does not necessarily mean you have a labral tear, but it does mean there is something going on in your hip joint: labral tear, hip impingement, hip arthritis. More imaging is needed to diagnose, and a hip arthroscopy could help treat.
Extra-articular hip pain includes things that are around the hip but not in the hip. For example, bursitis is to the side of the hip. Injuries to the gluteus or hamstring could also be here. Hip arthroscopies aren’t a treatment for extra-articular hip pain.
Hip cartilage
The hip has two types of cartilage: the labrum and articular cartilage.
The labrum is a special type of cartilage that is harder than the typical cartilage you think of and is meant to hold a suction seal on your hip joint to confer some stability to the joint while its going through its range of motion.
Articular cartilage is the bearing surface of the ball and socket and is between the bones. Articular cartilage is the cartilage primarily affected by arthritis. If someone has bone-on-bone arthritis, their articular cartilage is worn away between two bones so the bones are touching each other instead of the cartilage cushion.
Both bad arthritis and a labral tear can cause intra-articular hip pain.
Labral tears
If there is a big enough tear in the labrum or a tear located in the wrong place, the labrum will lose the suction seal on the joint. When the suction seal is lost, it can cause a microinstability leading to pain in certain situations, especially at the end range of motion.
Femoroacetabular impingement (FAI)
When a ball and socket are healthy, they fit congruently together and allow for a full arc of movement. Some people have an extra bit of bone on the ball (femoral head), the socket (acetabulum), or both. When someone has the extra bone, the bone can interfere with the arc of movement of the hip and limit how it moves. The extra bone may bump on the labrum repeatedly and cause a labral tear. FAI is frequently the underlying cause for someone who has a labral tear but does not have arthritis.
When the extra bump of bone is on the ball it’s called a cam impingement. When the extra bump of bone is on the socket it’s called a pincer impingement.
Loss of hip mobility can also predispose someone to other injuries down the line, such as knee injuries like ACL tears.
Treatment for Labral Tears
In most circumstances, surgery is a last resort. While there are times we do surgery on an urgent basis, we try to avoid it.
Non-Surgical Treatment
Pain from a labral tear is often from the microinstability that the tear causes on the hip joint. If the lack of stability is treated, many people – some studies suggest as many as 80% — will feel better with physical therapy to strengthen the muscles around the hip joint. Strengthening the key stabilizer muscles around the hip joint can eliminate the pain and you would not need surgery unless the symptoms continue to interfere in your daily life.
For example, while most people know about the gluteus muscle, many don’t know that it comes in three parts. The gluteus maximus is frequently discussed and exercised, but the gluteus medius and minimus are important pelvic stabilizers that are less discussed and are frequently weak, even in people without an injury. If the gluteus medius is strengthened, it can confer some stability around the hip joint. While the labrum won’t be fixed without surgery, physical therapy can make the symptoms not as impactful on the patient and remove the need for surgery.
Surgical Treatment
If physical therapy works, surgery may be needed. In an arthroscopic surgery, we make three small holes around the hip. Tiny anchors or plastic screws go into the bone, with stitches that go around the labrum and then zip tie it back into place to heal. Orthopedists are gardeners, not carpenters. Putting the labrum back into place does not automatically equate to healing; what happens next depends on the body. During the surgery, we’ll smooth out any impingement so the extra bumps of bone don’t keep hitting the labrum. The underlying problem, the labral tear, and the underlying cause, the impingement, can be treated in the same surgery.
Arthroscopic surgery does not mean it’s a minor surgery: it just means that the surgery has small looking incisions. A hip arthroscopy is a major surgery. Crutches will be needed for usually four to six weeks. Some patients may need a hip brace during that time period. Any kind of high impact activity like running or heavy lifting will take on the order of three months after surgery.
Full return from this surgery back to high-level activity can take six to twelve months. However, return to sport is not one moment in time but rather a process by which people gradually reintroduce activities. It’s not a quick fix, but an opportunity to work together on resetting your hip mechanics and then building strength and stability along with mobility for a lifetime.
Frequently asked questions
How much physical therapy is needed after a hip arthroscopy?
While it varies by patient, on average its between three to six months. The first three months is restoring you to a regular activity level. For people who are going to be higher-level athletes or people who have a slower recovery for other reasons, it’s more in the order of six to nine months. The rehab starts off very basic and over time becomes more like a workout.
Is there an upper age limit or a lower age limit for a hip arthroscopy?
There isn’t a chronological age limit, but there are some factors to make the decision. On the lower end, there is a preference that someone has their growth plates closed before undergoing a hip arthroscopy. On the upper end, the factor is how well-preserved the joint is. People who have lost a fair amount of cartilage in their joint, which tends to happen with age, are not going to do well with a hip arthroscopy.
How is a hip arthroscopy different from a hip replacement?
A hip arthroscopy is a hip preservation tool by fixing things that are torn to have more longevity. A hip replacement is a reconstructive situation or a salvage procedure, where the joint has worn out to the point where it can’t function as the patient needs and is interfering with their quality of life. Two different mentalities, two different rationales, and they’re used for two different situations.
Are there any permanent activity modifications after a hip arthroscopy?
There is no prescribed activity restriction for everyone, but I am going to talk with you about what you want to do with your hip and decide if the activities you want to do are worth the risk to yourself. Sometimes people’s livelihood relies on their ability to use their hip in a specific way, but other times there is a high-risk activity someone enjoys but there may be a substitution for it.