Hip Instability and Hip Microinstability: A unsuspected primary cause of your hip pain

Ross A. Hauser, MD; Danielle R. Steilen-Matias, MMS, PA-C

For many people, long before they have the sensation that their hip is “giving out,” they have significant hip pain. Originally it was a pain that came and went, but as time went on, the pain became more constant and more intense. They, like you, started to notice more pain with walking steps or up hills. It was on an incline that many felt their hip “give way” for the first time. Now these people’s hips became problems of more than just pain, it became a problem of hip instability. As time went on they noticed a creeping knee pain, ankle pain and pain in the low back develop as well. Walking became a more trying issue.

Part 1: An Explanation of Hip Instability

  • When your body thinks hip swelling is necessary to hold the joint together.
  • Hip instability causes almost all chronic hip pain conditions.
  • Your hip is moving abnormally within the joint. Sometimes, the hip ball falls out of the hip socket.
  • The challenge of diagnosing Hip Instability and Micro instability: The challenge of finding the source of pain.
  • Damage to hip ligaments; it does not take much to cause hip pain.
  • The total impact of hip instability on the musculoskeletal system
  • When one ligament is damaged, it can cause instability which can cause the hip joint, the pelvic joints, and the lumbar spine to falter, changing the way you walk.

Part 2: Hip Microinstability

  • Hip micro instability was causing “bone on bone.”
  • Patients with hip micro instability had significantly greater ROM. That’s how you can tell that they have hip micro-instability.
  • “Hip micro instability is an established diagnosis; however, its occurrence is still debated by many physicians.”
  • Diagnosing microinstability of the hip.
  • Diagnosing idiopathic microinstability is more complicated because there is no single definitive physical test or imaging study that can be used to easily both identify the cause(s) and/or confirm the diagnosis.
  • Symptoms of hip microinstability.
  • “There are many treatment options and when managed appropriately based on the precise cause of micro-instability, patients may demonstrate improved outcomes.”
    Connective tissue disorders associated with hip microinstability.

Part 3 Walking and gait abnormalities

  • When one ligament is damaged, it can cause instability which can cause the hip joint, the pelvic joints, and the lumbar spine to falter, changing the way you walk.
  • Why do I waddle like a duck? Weak muscles and the Trendelenburg gait.
  • Under normal circumstances, the hip joint, its capsule, and ligaments routinely support two-thirds of the body weight.
  • If you cannot walk with normal biomechanics the whole body can be affected.
  • Muscle weakness and gait abnormalities.
  • A pelvic drop on the non-weight-bearing side while standing on one limb.
  • Prolotherapy injections: Treating hip ligaments.
  • X-ray of a normal hip compared to a steroid-injected hip.
  • Prolotherapy for Chronic Hip Pain and Associated Conditions.

Part 4 Treatment guidelines

  • Prolotherapy injections: Treating hip ligaments.
  • X-ray of a Normal Hip compared to a Steroid-Injected Hip.
  • chronic tight hip flexors, snapping hips, and other instability-related conditions.
  • Prolotherapy for Chronic Hip Pain and Associated Conditions.

Part 1: An Explanation of Hip Instability


Hip instability, also called ‘hip joint looseness’ is the suspected primary cause of hip osteoarthritis and the eventual need for a hip replacement. As described above and perhaps most importantly to you, hip joint looseness is the suspected primary cause of your hip pain, the sensation that your hip is giving out, and you have pain from your lumbar spine to your knee.

When your body thinks hip swelling is necessary to hold the joint together

Where does hip instability come from? Most patients realize that their problems are problems of degenerative wear and tear. Few people have a good understanding however of the cause of the degenerative wear and tear and these people who do, are mostly the ones who had previous hip arthroscopic surgeries. That’s the clue, hip arthroscopic surgery addresses the problems of soft tissue damage, the hip labrum, the hip tendons, the hip muscles, and sometimes, the hip ligaments. Hip instability occurs from the inability of the hip joint connectors, that is the hip ligaments, the soft tissues that connect and hold the hip and pelvic bones in place, to actually be strong enough to hold the hip in proper alignment or in a stable, strong position in relation to the lumbar spine, pelvis, and knees.

This hip ligament laxity causes extra movement of the bones, which then stretches the hip joint capsule, especially the inner lining of soft connective tissue known as the synovium. When this soft tissue is stretched, it causes the creation and secretion of extra joint fluid. In other words, swelling of the hip. Your body thinks this hip swelling is necessary to temporarily stabilize the hip and prevent further hypermobility.

Hip instability causes almost all chronic hip pain conditions.

Typically, pain is treated in one of four ways:

  • Mask the pain with pills or steroid shots.
  • Decrease the force on the tissues by reducing activity (sit more and stand less).
  • Undergo surgery in an attempt to get rid of the pain.
  • Strengthen the weakened tissues so that they can handle more force.

Regenerative medicine injections such as those discussed above, work on treating chronic hip pain by strengthening the weakened injured tissues so they can handle more force of body weight impact. It is amazing how often people think that the care they are receiving is helping them when in reality it is hurting them. This is the case with NSAID medicationssteroid injections, and inactivity.

The person who does not address the actual underlying cause of their pain may not realize that their condition is actually worsening, despite how they feel. This is easy to understand when people take narcotic, anti-inflammatory, or nerve-deadening medications to decrease their pain while the underlying ligament laxity is actually worsening while they play sports, exercise, or do other activities such as simply walking.

Joint instability is a progressive disorder. Those who say that arthroscopy helped their hip pain but still need anti-inflammatory medications to get through the day are deluding themselves, much like the person who says that hip arthroscopy helped but now doesn’t run, play tennis, or do any significant exercise anymore. These patients have not resolved their pain, they are just managing it. There is a big difference between pain resolution and pain management. Procedures like steroid injections and medications like NSAIDs and narcotics can manage pain, but only treatments aimed at resolving the root cause of the pain can alleviate it.

Your hip is moving abnormally within the joint. Sometimes, the hip ball falls out of the hip socket.

Your hip is moving abnormally within the joint and sometimes falls out of the hip socket. All the while pain occurs when the nerve endings in the stretched ligaments send pain signals to the brain which then initiates a specific ligamento-muscular reflex to help stabilize the joint by limiting motion from muscular spasm and tightness. This is demonstrated in the video above.

So there you have it. Instability in the hip causes stretching of the soft tissue which causes pain. Swelling tries to make a “water cast” to get your hip in place. Muscles spasm as they also try to hold the joint together. All this is the end result of the instability of the hip.

These mechanisms, joint tightening by joint swelling and muscular tension are nature’s way of dealing with an injury. Swelling and spasms temporarily limit further hip damage and give the injured structures, such as the ligaments, a chance to heal. However, if the joint instability is not resolved and pressure and abnormal motion remain in the hip, the inflammatory joint fluid (chronic swelling) and muscle spasms are now joined by bone spur formation. Bone spurs are also Nature’s way to fuse the hip to provide greater stability. This will eventually cause a myriad of chronic medical conditions including nerve compression and entrapments, osteoarthritis, avascular necrosiship bursitistendinopathy, and/or tendon/ligament/labrum/meniscus tears,  all of which have a cascading effect on each other leading to muscular weakness, poor balance (see our article Hip instability and problems with balance and falls in the older patient), and repeating the cycle in the other hip, knees, and low back.

If hip instability continues, then arthroscopic surgery is usually recommended. But is it needed? Does the surgery make the instability worse?

This article’s focus will be on identifying hip micro instability and instability and if surgery can be avoided. For more detailed discussions on surgery repairing or surgery causing hip instability please see our articles

Below is a video of a patient who has demonstrative popping of the hip. This image is taken with Dynamic Digital Radiography: Watch the bones and how much the hip moves out of place and is unstable.

The hip joint has three functions: stability, shock absorption, and mobility.  The hip joint acts as a weight-bearing joint that carries the weight of the torso, upper limbs, head, and neck. It acts as a shock absorber by absorbing forces acting on the lower and upper bodies and dampening them as they pass through the hip to the other half of the body. The hip joint also allows the lower limb to move as needed for locomotion, kneeling, sitting, and the like.  As is true with all joints, there is a trade-off in the hip joint between motion and stability; and because the hip joint’s predominant role is as a stabilizing, weight-bearing joint with shock-absorbing properties, the mobility of the hip itself is somewhat limited.

The hip joint is assisted in its stabilizing, weight-bearing, and shock absorption functions by surrounding muscles, muscle groups, and tough ligaments. Like all synovial joints, the hip joint has an articular capsule, articular cartilage and synovial fluid. The articular capsule surrounds the joint and it is composed of an outer layer known as known as the hip capsular ligament.  This capsular ligament holds the femur bone to the acetabulum.  The hip joint capsule is strong and supported by three extracapsular ligaments: iliofemoral, pubofemoral, and ischiofemoral. A single intracapsular ligament, called the ligamentum teres, attaches at the acetabular fossa and the fovea of the femur (simply the ball to the socket).

The challenge of diagnosing Hip Instability and Micro instability: The challenge of finding the source of pain

Instability in one joint puts other joints at risk for instability over time and it may not always be clear where the pain source is located. In cases where the presence of hip instability as a cause of hip pain is uncertain, or it’s not clear as to what the source of pain is, there is one diagnostic test that works well to determine if the source of hip pain is generated in the hip joint or is referred pain from some other location. This test involves the use of a local anesthetic injected into the hip joint. This is called an intra-articular joint injection. If the pain is eliminated after the injection, then the source of pain is the hip joint. But if the pain continues after the injection, it is more likely that the pain is referred pain from some other damaged structure. This technique is especially useful for distinguishing if pain originates in the hip joint. It is inexpensive, readily available, safe, and relatively accurate.

What are we seeing in this image? The ligament attachments of the hip and pelvis

In this image, we see the front of the pelvis and the many ligament attachments that hold the two halves of the pelvis and hip joints together and connect the pelvis and hip joints to the lower lumbar spine. We see how the intertransverse ligament, anterior longitudinal ligament, anterior sacroiliac ligamentsiliolumbar ligaments, and pubofemoral ligaments all interact to provide stability or when they are injured cause hip instability.

The stability of the hip is largely due to its unique anatomical features, particularly the strong ligaments of the joint. The capsule surrounds the hip joint and most of the femoral neck to increase stability and prevent the dislocation of the joint and is made up of strong ligaments.

Damage to hip ligaments; it does not take much to cause hip pain, instability, and degenerative hip disease.

When a person has capsular ligament laxity, there is a significant increase in joint rotations and femoral head translation and an abnormal movement path of the femoral head center. In other words, hip capsule instability allows the ball of the hip to bang around and eventually pop out of the socket and the ball floats within the joint. This was alluded to by a May 2018 paper in The American Journal of Sports Medicine (1) which wrote: “Capsular laxity alters normal kinematics (joint rotation and femoral head translation) of the hip, potentially leading to abnormal femoral-acetabular contact and joint degeneration.”

When the hip capsule soft tissue components are overly stretched, as commonly occurs with arthroscopy and the various causes of hip instability, the femoral head gets inferiorly (pushed down) displaced during external rotation (when you rotate your knee outward)  and Antero-inferiorly (down and forward in the hip joint) displaced during internal rotation (when you rotation your knee inward).

  • The amount of this displacement may only be one-tenth of an inch or less, but that could be all that is necessary to overstretch ligament tissue and cause severe pain.

Let me further explain.  Let’s say a patient has posterior (back of the) hip pain and is especially tender in the piriformis muscle belly, the gluteus medius, and Maximus muscles attachments onto the iliac crest. Their tight piriformis muscle might even be compressing the sciatic nerve, giving the person sciatica. We know that when anterior hip instability is present, the body will recruit various hip extensor muscles to limit the anterior motion of the hip through the ligamento-muscular reflex. (This occurs when the muscles surrounding the joint become tense and spasm as a compensatory way to stabilize the joint).

Likewise, a person with psoas muscle spasms who is experiencing tight psoas and anterior hip pain probably has some degree of posterior hip instability. The overstretched posterior hip ligaments (especially the ischiofemoral) initiate the psoas tightening through the ligamento-muscular reflex to protect the joint

In cases of hip instability, muscles that surround the joint may lose strength. Muscles do not have power unless the joint is stable. Let’s repeat: muscles do not have power unless the joint is stable. This is why many patients with instability complain of weakness, poor balance, and the hip giving way. These patients likely have laxity in the hip ligaments and subsequent muscle weakness.

In the image below we see trochanteric bursitis. The bursal sac is inflamed because the gluteus medius muscle is irritating it. This occurs because the gluteus medius muscle has to contract so much to help stabilize the pelvis and hip because of underlying hip instability from a hip labral tear or hip ligament injury. In the image, we see the gluteus medius muscle, the iliofemoral ligament injury, the inflamed trochanteric bursa, and the femur bone.

In the image below we see trochanteric bursitis. The bursal sac is inflamed because the gluteus medius muscle is irritating it

I cover this further in my article Hip pain and hip instability | What happens if hip muscles are weak?


The total impact of hip instability on the musculoskeletal system

Hip microinstability and hip instability are typically part of an overall body instability. The onset of this can be traced to microinstability in many patients. This is why another useful concept to consider when evaluating the hip (or any other joint for instability) is to consider the adjacent joints. While it may be obvious to consider the anatomy of the knee and ankle/foot when a patient complains of hip pain with walking, it isn’t always common practice to evaluate the pubic symphysis and ipsilateral sacroiliac joints for instability. The hip joint socket or acetabulum is part of the pelvic girdle, which consists of three bones the ilium or the iliac crest, pubic bone, and ischium. These three bones were separate early in life but joined to form one solid bone in adulthood called the innominate bone. The innominate bone has three articulations: the iliac crest with the sacrum forming the sacroiliac joint; the acetabulum with the femur bone forming the hip; and the two pubic bones meeting at the pubic symphysis. All of these joints are primarily held together by ligaments.

Please see our articles:

In the image below, we see a pelvis x-ray showing clues of hip and pelvis instability in an extremely hypermobile patient. A widened public symphysis, sacroiliac joints, and hip spaces (arrows) are noted. The treatment of Prolotherapy is discussed below.

hip and pelvis instability in an extremely hypermobile patient.

The impact of hip instability, lumbar instability, and pelvic instability are discussed at length in these articles

Hip labral tears

It is important to understand that when the hip capsule stretches, a medial translation (the ball is moving towards the center of the hip joint) of the femoral head in extension (knee moving outward) and a lateral translation (the ball is moving towards the side of the hip joint) of the femoral head in flexion (the knee is moving upwards towards your head) and internal rotation (knee moving inwards towards the other knee) will occur, with each of about 1 mm. This was assessed in an April 2020 paper in the journal Arthroscopy, Sports Medicine, and Rehabilitation (2) With capsular ligament laxity, the primary area of contact of the femoral head and the labrum is located in the superior (the top) and posterosuperior (back top) sectors of the acetabulum rim.

This is the exact location where most labral damage, including tears, is located. With hip capsular ligament laxity, a slight opening between the femoral head and the anterosuperior labrum occurs. (3) This can allow synovial fluid to escape, undermining the sealing function of the labrum and increasing the contact pressures between the hip articulating surfaces. Thus, relatively small translations of the femoral head can lead to large increases in cartilage pressure, which can then ultimately lead to cartilage degeneration and hip osteoarthritis. In summary, capsular laxity-induced microinstability of the hip can have many long-term ramifications.


Part 2: Hip microinstability


In this section, we will present research and clinical observations on injuries to the hip that are sometimes so small that a new medical term for this condition was developed called hip microinstability. We also hope to demonstrate how microinstability affects the function of not only the injured hip joint but also the adjacent joints (the lumbar spine, the knee, and the pelvic attachments) with which it shares the responsibility for movement. Microinstability is also known as a sub-failure injury(ies) to one or more ligaments. Injuries of this nature are hard, if not impossible to detect by static X-rays or MRIs. They require motion, as in digital motion X-rays or dynamic high-resolution ultrasound to properly evaluate.

Hip micro instability was causing “bone on bone.”

Microinstability is increasingly gaining support as an accepted cause of young, non-arthritic hip pain. Patients with hip microinstability may experience hip joint pain, unsteadiness, or apprehension.

An April 2022 study in the journal Arthroscopy, Sports Medicine, and Rehabilitation (4) looked at femoral head chondral damage in patients with instability in contrast to those with femoroacetabular impingement (FAI) without instability. The idea was to see if hip instability caused degenerative wear and tear on the cartilage.

  • In 32 patients identified as having central head chondromalacia (degenerative wear on the femoral head), 81% were diagnosed with instability. This finding that a high percentage of patients with central femoral head chondromalacia were found to have hip microinstability suggested that there is a pattern of femoral head chondral damage in patients with hip microinstability. Hip micro instability was causing “bone on bone.”

Patients with hip microinstability had significantly greater ROM. That’s how you can tell that they have hip microinstability

A June 2023 study in the Orthopaedic Journal of Sports Medicine (5) sought to determine the impact of ligament weakness in hip instability and to help guide surgeons on surgical decisions during the surgery. If they knew how much instability there was in the hip, they could possibly have more successful outcomes.

Background: “Hip micro instability is an increasingly recognized cause of pain and disability in young adults. It is unknown whether differences in passive hip range of motion (someone is helping you move your hip around) exist between patients with versus without hip micro instability.” The idea is, how far can a clinician, without injuring, move a hip beyond its normal range of motion, and is there a difference in how much range of motion can be created between those people with hip micro instability and those without it? The thinking here is that “Underlying ligamentous (ligament) and capsular (hip joint) laxity will result in differences in clinically detectable passive hip range of motion between patients with femoroacetabular impingement (FAI), patients with micro instability, and asymptomatic controls.”

  • Patients with a diagnosis of isolated microinstability based on intraoperative (during an arthroscopic surgery) findings were identified and classified as having isolated femoroacetabular impingement (FAI), instability, or FAI plus hip instability.
  • In total, 263 hips were included:
    • 69 with isolated instability,
    • 50 with femoroacetabular impingement,
    • 50 with femoroacetabular impingement and instability, and
    • 94 control hips (no diagnosed instability).
    • A higher proportion of patients in the instability and femoroacetabular impingement groups were female.

Conclusion: Patients with hip micro instability had significantly greater ROM than symptomatic and asymptomatic groups without hip micro instability.

“Hip microinstability is an established diagnosis; however, its occurrence is still debated by many physicians.”

In July 2016, doctors at the Steadman Philippon Research Institute published a paper on the microinstability of the hip and described it as a previously unrecognized degenerative hip disease. This is what they wrote in the publication Muscles, Ligaments, and Tendons Journal (6)

“Hip microinstability is an established diagnosis; however, its occurrence is still debated by many physicians. Diagnosis of hip microinstability is often challenging, due to a lack of specific signs or symptoms, and patients may remain undiagnosed for long periods. This may lead to early manifestation of degenerative joint disease. . . Conservative treatment is considered the best initial approach, though, surgical intervention should be considered if symptoms persist or other hip pathology exists. Successful surgical intervention, such as hip arthroscopy, should focus on restoring the normal anatomy of the hip joint in order to regain its functionality.”

In April 2022 an International Microinstability Expert Panel published these updates on hip micro instability in the journal Knee Surgery, Sports Traumatology, Arthroscopy (7): “Hip microinstability is a relatively new diagnosis which is increasingly being discussed in the literature and yet there are no clear guidelines for making a diagnosis. Microinstability has generally been defined as persistent excessive hip motion that has become symptomatic, especially with pain.” The purpose of convening this expert panel was to provide the first expert consensus on diagnosing hip microinstability. The expert panel was comprised of 27 members: 24 (89%) orthopaedic surgeons and 3 (11%) physiotherapists from around the world.”

After analysis and discussion, the expert panel was able to deliver a consensus on diagnosing hip microinstability, however, they write: “The relative complexity of the final diagnostic tool is illustrative of the difficulty clinicians face when making this diagnosis.” Even with diagnostic tools, making this diagnosis is difficult.

Diagnosing Microinstability of the Hip

In our experience, suspicion of microinstability must be present for diagnosis. This is not a play on words, a clinician needs to be aware of the problem of microinstability to be able to understand to look for it. The research above points out that this knowledge may not be present at every doctor’s office.  The diagnosis of microinstability of the hip is based on patient history, physical examination, and radiographic findings.

People with idiopathic (of unknown cause) hip microinstability will often describe hip pain that can range from feeling sharp or burning to a generalized dull ache. The pain can be constant or intermittent and range in severity or location. It may often radiate to other structures, such as the knee or down the leg. It is helpful to note whether or not the pain occurs or worsens when performing movements that require repetitive hip rotation during axial loading. Patients may complain of a feeling that their hip is ‘locking up’ or ‘giving way’ or of mechanical symptoms such as snapping clicking, popping of the hip, or stiffness upon waking or after sitting. Often, the pain will present with symptoms of sports-related groin painpost-hip replacement groin pain,  buttock painPiriformis Syndrome, Sciatica PainFemoroacetabular Impingement type pain, and thigh pain.

The diagnosis of idiopathic joint instability is suspected when complaints of hip pain and findings of joint hypermobility are both present.  Hip instability diagnosis is primarily made on the basis of clinical grounds (symptoms) and secondarily by physical examination. However, hip microinstability can be a subtle finding.

Diagnosing idiopathic microinstability is more complicated because there is no single definitive physical test or imaging study that can be used to easily both identify the cause(s) and/or confirm the diagnosis.

Diagnosing idiopathic microinstability is more complicated for the orthopedic surgeon and the patient because there is no single definitive physical test or imaging study that can be used to easily identify the cause(s) and/or confirm the diagnosis. Not only can the symptoms of hip microinstability be subtle, but also there is usually no identifiable precipitating event that caused them aside from ‘overuse’. This does not mean microinstability should be ruled out if the patient experienced some kind of acute trauma to the hip. For example, athletes who have experienced traumatic injury may already have subclinical joint laxity, which enables them to have the flexibility and range of motion they need in order to be competitive in their sport but also predisposes them to injuries that can cause more severe instability. This is especially true for ballet dancers and gymnasts.

Radiographic Findings 

Traditional hip imaging has historically been unable to diagnose hip microinstability. This is because patients are static while images are taken, as opposed to being able to image the patient while they are moving. Those with hip instability may have normal imaging in a static position, as no strain is placed on the ligaments or surrounding soft tissue, making it unable to assess ligamentous injuries. However, there are new developments in hip imaging that may change this.

Symptoms of hip microinstability

A number of indicators can be documented, including:

  • excessive motion,
  • hip clicking or cracking (crepitation) sounds,
  • hip grinding sounds or sensations,
  • impingement with specific motions.

Some patients may even be apprehensive of passive hip movement due to fear of pain, hip dislocation, or subluxation. In addition, the clinician who suspects microinstability can try to reproduce the symptoms by palpating specific points, testing the range of motion, and/or having the patient perform certain movements.

“There are many treatment options and when managed appropriately based on the precise cause of micro-instability, patients may demonstrate improved outcomes.”

An April 2022 review study from McMaster University (8) suggested data on the most common causes, diagnostic features, treatment options, and outcomes of patients with hip microinstability. In this review of 189 patients (193 hips), 89% were female the most commonly used features for diagnosis of micro-instability on history were:

  • Anterior (front of hip) pain in 146 (78%) patients and a subjective feeling of instability with gait in 143 (81%) patients, while the most common feature on physical examination was the presence of anterior apprehension with combined hip extension (pain at the front of the hip when, with the patient laying on his/her back and their feet dangle over the die of the table, the pressure was applied to the knee and external rotation in 123 (65%) patients. The most common causes of micro-instability were iatrogenic (unknown cause) instability secondary to either capsular insufficiency (iliofemoral ligament failure of failed arthroscopy) or cam over-resection (failed surgery) in 76 (62%) patients and soft tissue laxity in 38 (31%) patients.

The researchers concluded: “There are many treatment options and when managed appropriately based on the precise cause of micro-instability, patients may demonstrate improved outcomes.”

Connective tissue disorders associated with hip microinstability

Microinstability associated with connective tissue disorders is fairly easy to diagnose because the symptoms of these conditions are clustered in known patterns. Down’s syndrome, Marfan syndrome, or Ehlers-Danlos Syndrome (EDS) are examples. (Also see my companion article Ehlers-Danlos Syndrome and Hip Replacement Complications). In my practice, I first evaluate the thumb and fingers to assess the amount of systemic laxity in a person. People with EDS or hypermobility can often touch their thumbs with their forearms and bend their fingers back beyond 90 degrees.


Part 3 Walking and gait abnormalities


When one ligament is damaged, it can cause instability which can cause the hip joint, the pelvic joints, and the lumbar spine to falter, changing the way you walk.

ligaments all interact to provide stability or when they are injured cause hip instability.

  • Iliofemoral Ligament (ILF): The iliofemoral ligament is the strongest ligament of the human body and thus the strongest ligament of the hip capsule. It is located at the front of the hip joint and originates from the ilium (the wings of the pelvis), immediately below the anterior inferior iliac spine. The ligament is Y-shaped because it attaches to the intertrochanteric line (attaches at the femur) in two places. It prevents hyperextension of the hip joint.
  • Pubofemoral Ligament (PF): The pubofemoral joint is located to the front and below the hip joint complex. It attaches at the pelvis to the iliopubic eminence and obturator membrane (the tissue that helps stabilize the hip through external rotation) and then combines with the articular capsule. Above you can see that it lies in the front of the hip joint and adds to the stability of the hip by preventing excessive abduction and extension.
  • Ischiofemoral Ligament (ISF): The ischiofemoral joint is located above and behind the joint and originates from the ischium of the pelvis and attaches to the greater trochanter of the femur. The ISF limits internal rotation in both flexion and extension as well as limits posterior translation.

As you may be able to visualize in the above image. When one ligament is damaged, it can cause instability which can cause the hip joint, the pelvic joints, and the lumbar spine to falter, changing the way you walk, the way you favor other limbs, and the way you move and function. This is why correcting the underlying ligament injury is so important so other ligaments in the hip, pelvis, and spine, do not become injured trying to support and replace the function of the damaged ligament. No ligament is an island and while each ligament may have a primary motion it protects, it can be called upon to resist another motion if the primary stabilizing ligament is injured.

The iliofemoral ligament (in red)

Due to its location at the front of the hip, injury to the iliofemoral ligament (ILF) can significantly affect the anterior (front) stability of the hip joint. However, it is best to think of the hip joint capsule and surrounding ligaments as being one ‘big mesh’ versus independent structures. For example, the Pubofemoral ligament ligament does not have a distinct insertion site but rather blends with the iliofemoral ligament, Ischiofemoral Ligament, and hip capsule. These ligaments (iliofemoral ligament, Ischiofemoral Ligament, Pubofemoral ligament) essentially wind around the hip joint and create a ‘screw home’ mechanism to stabilize the hip. (9) In hip extension these ligaments and hip capsule tightens and compress (“screw”) the femoral head into the acetabulum.

Why do I waddle like a duck? Weak muscles and the Trendelenburg gait

Click on the video to watch Dr. Hauser demonstrate gait abnormalities.

Under normal circumstances, the hip joint, its capsule, and ligaments routinely support two-thirds of the body weight.

In the video clip above – Dr. Hauser demonstrates various gait abnormalities observed in patients. The Trendelenburg gait is the walking motion of waddling like a duck.

Click on the video link to see:

  • Normal gait.
  • Mild abnormality. The walk is slower. The steps are close together.
  • Moderate abnormality. The walk is much slower, and off-balance.
  • Much slower gait.
  • Severe abnormality. The stiff right hip is very evident.
  • Extreme abnormality. Terrible balance, no hip motion.

The video loops – you can pause it at any time to continue with the article.

If you cannot walk with normal biomechanics the whole body can be affected.

When a person does not have the range of motion necessary to biomechanically move in a normal way, the body will compensate and stresses or forces will get transferred onto other structures. If you cannot walk with normal biomechanics due to loss of hip or knee flexion or extension, the forces travel to the next adjacent joints, which are the ankle, pubis, sacroiliac joint, and lumbosacral spine. Long-term, one can expect increased motion and resultant stresses and pain at these joints if the hip pain and instability are not resolved. The longer an instability problem has gone on, the more likely adjacent joints are involved. Loss of joint motion does not necessarily mean that the person has a loss of cartilage and terrible bone spurs; it often means the body is using surrounding muscles to guard the joint because it is unstable.

Muscle weakness and gait abnormalities.

When the passive restraints of the soft tissue stabilizers (the ligaments and tendons) are damaged, the hip becomes reliant on the dynamic stabilization of muscles. However, if the muscles in the lower extremities are weak, hip joint instability is even more likely to occur. Some of the most common gait abnormalities are typically the result of the weakness of the hip abductor muscles. These are those people that often ‘waddle like a duck. During normal walking, the weight of the upper body is carried equally first by one hip and then by the other as each foot connects with the ground.

  • When the hip abductor muscles (gluteus medius and minimus) are weak, the stabilizing effect of these muscles is lost. This makes it difficult to support the body’s weight on the affected side.
  • The weakened abductor muscles allow the pelvis to tilt down on the opposite side.
  • To compensate, the trunk lurches to the weakened side in an attempt to maintain a level pelvis. This condition is called a compensated Trendelenburg gait or gluteus medius limp. The Trendelenburg sign is observed when a person with moderate hip abductor weakness has a pelvic drop on the non-weight-bearing side while standing on one limb.

A pelvic drop on the non-weight-bearing side while standing on one limb.

The Trendelenburg gait demonstrates how the body will naturally try to find a way to compensate for weakness in order to enable motion and function to continue. When instability of the hip first occurs, the pelvis and lumbar spine can compensate to take the pressure off of the hip, and gait abnormalities are not seen. However, if one body part cannot move in an efficient energy-consuming manner, the body will find another way to achieve motion. For example, if loss of hip motion occurs from osteoarthritis, compensatory mechanics are observed, including increased intra-articular pressure, increased mobility of the knee on the same side, increased mobility of the contralateral hip, and increased mobility of the lumbar spine and pelvis.

When there is a loss of hip extension, as is common in cases of advanced osteoarthritis of the hip, an exaggerated anterior pelvic tilt of the pelvis occurs. During walking, when the foot on the side of the osteoarthritic hip hits the ground and it is time for the hip to extend and the heel to lift to begin the next step, the lumbar spine goes into excessive lumbar lordosis to compensate for the loss of hip extension. This loss of mobility of one hip can put the same side knee, lumbar spine/pelvis, and the other side of the hip at risk for instability. This is why it is important to correct the initial cause of hip pain (hip instability) and stop this progression from occurring.

Summary of gait abnormalities

The May 2022 update to STATPearls, (10) a publication of the United States National Library of Medicine, suggests starting with physical therapy and exercise to correct the waddling walk. “Trendelenburg gait by itself wears the hip joint, and appropriate treatment is essential. Physical therapy is the mainstay treatment for gluteus medius and minimus weakness. Physical therapy involves strengthening the weakened hip abductor muscles. This involves lying on the unaffected side while abducting the affected leg up towards the ceiling. A theraband can be applied on the lower limb to increase the resistance during the exercise. Other modalities include lateral side steeping and balance exercises.”

However, those with joint pain will walk or put excess pressure on the nonpainful, other side limb, due to compensation. In an attempt to decrease pressure on the painful joint, forces naturally get transmitted to adjacent joints/limbs. In the hip, if anterior instability progresses, it will lead to posterior hip instability, SI joint instability, knee instability, and even other side hip instability, etc. Eventually, these joints can develop osteoarthritis.


Part 4: Treatment guidelines

A January 2019 paper in The Journal of the American Academy of Orthopaedic Surgeons (11) offered treatments and surgical recommendations. This paper is the work of Marc R Safran, MD. of  Stanford University, Department of Orthopaedic Surgery.

“The hip has generally been considered an inherently stable joint. However, the femoral head moves relative to the acetabulum (the ball can move erratically in relationship to the socket and cause unnatural wear and tear motion. The origins of hip osteoarthritis and bone on bone hips). Although the bones are primarily important in hip stability, the importance of the soft tissues (ligaments, tendons, labrum) has recently been demonstrated. Symptomatic microinstability of the hip is defined as extra physiologic (hypermobility) hip motion that causes pain with or without symptoms of hip joint unsteadiness and may be the result of bony deficiency and/or soft-tissue damage or loss. Recent work has helped improve the ability to identify microinstability patients preoperatively. Initial management begins with activity modification and strengthening of the periarticular musculature. Failing nonsurgical management, surgical intervention can be beneficial, focusing on the treatment of the underlying cause of microinstability, as well as associated intra-articular pathology. Bony deficiency may be treated with a redirection osteotomy (bone breakdown or bone spur overgrowth treated by bone shaving and remodeling), whereas those with adequate bony coverage may be treated with capsular plication (tightening up the hip capsule by repairing damaged soft tissue), capsular reconstruction (not enough soft tissue left in the hip and the use of autograft (a tendon or other tissue is taken from you and moved into the hip, or an allograft (donor material), and/or labral reconstruction.”

Above, this paper helps take us on the path from microinstability of the hip to eventually a need for arthroscopic procedure and then onto eventual hip osteoarthritis. Once subtle anatomical hip abnormalities are present, these repetitive movements may be more likely to contribute to hip instability. The term ‘microinstability’ suggests any pathological laxity (hip looseness) that leads to abnormal hip biomechanics (wobbly hip) without dislocation. As mentioned above, a constant main point to understanding the microinstability of the hip is the abnormal, hypermobility that allows the ball to bang against the socket and eventually wear each other out. In the hip, it refers to “symptomatic excessive motion of the femoral head within the acetabulum during functional activities.” Miniscule tears in the ligaments can cause microinstability, resulting in pain and joint laxity of the hip.

Staples or other attempts to secure tissue in hip arthroscopic procedures can leave it less pliable and at risk for further long-term damage. There are times that surgery is needed for more advanced cases that have lost most range of hip motion and have extensive destruction of the joint integrity.

Approximately fifty percent of people come to Caring Medical for help because no other physician can help them or they are seeking alternatives to the recommendations made by other physicians, such as cortisone injections or surgeries like labral repair or resection, osteotomy, chondroplasty, or total hip arthroplasty. Ten percent of our patients have already tried PRP hip injections or a stem cell injection (not injections) by another practitioner.

A summary of all the above in just one sentence would be: hip joint instability is most likely to occur anteriorly, even though the anterior ligament is the largest and strongest of the hip ligaments. Thus, for almost all hip conditions, Prolotherapy should be performed aggressively on the anterior hip, including the Iliofemoral ligament and hip capsule.

Prolotherapy injections: Treating hip ligaments

As we have discussed above, hip instability, hip microinstability, most painful hip conditions, and hip pain begin with damage to the ligaments that support the hip, pelvic, and spine structures. This ligament damage can then progress into degenerative conditions that include hip osteoarthritis, labral degeneration, snapping hip syndrome, bone spurs, femoroacetabular impingement, and more. Hip joint instability can cause all this. Until the hip instability is addressed and treated, the hip will continue to degenerate due to the destructive hip motions, (a wandering ball banging against the socket) the hip instability causes.

Cortisone injections are routinely used in traditional medicine to cover up the pain temporarily and have degenerative effects that lead to the early onset of osteoarthritis. Traditional treatments are not targeted to resolve the source of hip pain, which therefore leads to accelerated degeneration and the eventual need for hip replacement.

X-ray of a Normal Hip compared to a Steroid-Injected Hip

Right hip degeneration was accelerated in a patient following multiple steroid injections.

Right hip degeneration was accelerated in a patient following multiple steroid injections.

In this section, we are going to discuss treatments that can repair hip ligament laxity and damage, Prolotherapy.

Prolotherapy is s comprehensive regenerative injection treatment that targets the weakened ligaments that are causing hip joint instability and degeneration. They are also the real reason for underlying pain both in the hip and often referral pain in the legs or buttocks. To properly correct the instability, it is not a one or two-shot job. The injections need to be a strong enough solution and be done to the whole hip area. Our more comprehensive treatment techniques can safely and effectively eliminate hip pain, offering a much-needed alternative to hip surgery by stimulating the body to repair the supportive ligaments around the joint, as well as promoting cartilage regeneration.

In the image below we see the typical Prolotherapy injection sites for a hip treatment. This patient has 24 injection sites outlined. In our office, this is considered ONE prolotherapy treatment.

Hip prolotherapy injection sites

In our own published research, we found Prolotherapy is a good option for alleviating chronic hip pain and the need for most hip surgeries. The use of PRP or Bone Marrow Aspirate Concentrate Prolotherapy is also a good option for more advanced hip arthritis and labral tears. These treatments do not work for everyone, a careful evaluation and screening is necessary to consider patient candidacy. We do see patients who have been recommended for surgery or have tried cortisone, PRP, or stem cell injection at other clinics that did not resolve the pain, we may very well be able to help you. Because we focus on whole joint care, treating both inside the joint and all the supporting structures, this approach is more comprehensive and may be better suited for your case.

To demonstrate hip instability being caused by ligament damage, the hip joint should be adducted, externally rotated, and flexed. The Hauser Hip Maneuver does just this to stress the hip capsule and ligaments and test for stability. Typically, excessive motion, soft end feel, subluxation, and crepitation can be felt during this maneuver in unstable hips. In some cases, crepitation can even be heard.

Ross Hauser, MD, and Danielle Matias, PA-C discuss the types of cases we see at Caring Medical Florida with chronic tight hip flexors, snapping hips, and other instability-related conditions.

Prolotherapy for Chronic Hip Pain and Associated Conditions

For many people, Prolotherapy injections may present a viable option in treating their hip pain. Prolotherapy stimulates the repair of joint structures so that they get stronger and allows for the return to sports, exercise, and walking.

In 2009, I published a study (12) in which we looked at the result of treating 94 painful hips in 61 patients with dextrose Prolotherapy at an outpatient charity clinic. These cases were advanced cases with patients suffering from chronic hip pain (many for five years or more) of which 50% had been told by a physician or surgeon that they needed a hip replacement, another surgery, or that there was nothing else that could be done for them.

After an average of 4.7 treatments, overall pain levels decreased from 7.0 to 2.4 (on a 1-10 scale where 1 signified no pain), 89% experienced over 50% pain relief and 54% were able to completely stop taking pain medications. All the patients who were previously told they needed a hip replacement or other operation were able to avoid surgery with Prolotherapy. The most interesting statistic was that in the hip patients who were told that surgery was their only option, 0% could exercise for more than 30 minutes before Prolotherapy. But, after Prolotherapy, 74% could. This was a study among 61 patients and the treatments did not help everyone.

In a separate study, (13) we followed patients with labral tears or labral degeneration who underwent dextrose Prolotherapy treatments. On average, patients received 4.8 treatments with some requiring up to eight. Out of 19 patients, 54% of patients reported complete relief of their pain, and none of the 19 required surgery after the Prolotherapy. 95% reported complete relief of one symptom (i.e, pain, crepitation, stiffness, etc.) On average, pain at rest reduced from 5.0 to 0.7, pain during normal activities of daily living reduced from 6.8 to 1.0, and pain during exercise reduced from 7.5 to 1.3 (0 signifying no pain and 10 signifying the worst pain).

Summary

Most painful hip conditions begin with damage to the surrounding ligaments and progress into degenerative conditions that include hip osteoarthritis, labral
degeneration, snapping hip syndrome, bone spurs, femoroacetabular impingement, and more. Cortisone injections are routinely used in traditional medicine to cover up the pain temporarily and have degenerative effects that lead to the early onset of osteoarthritis. Traditional treatments are not targeted to resolve the source of hip pain, which therefore leads to accelerated degeneration and the eventual need for hip replacement. Staples or other attempts to secure tissue can leave it less pliable and at risk for further long-term damage. While there are times that surgery is needed for more advanced cases that have lost most range of hip motion and have extensive destruction of the joint integrity, Prolotherapy, PRP, and bone marrow aspirate concentrate injections may be an option afterward for post-surgical pain relief and soft tissue repair. Even better is seeking a Prolotherapy evaluation for painful hip conditions before the joint destruction is out of control. Prolotherapy offers a successful and much-needed alternative to hip surgery by stimulating the body to repair the supportive ligaments around the joint, as well as promoting cartilage regeneration. In our studies, we found Prolotherapy is an excellent option for alleviating chronic hip pain and the need for most hip surgeries.

We hope you found this article informative and that it helped answer many of the questions you may have surrounding your hip issues.  If you would like to get more information specific to your challenges please email us: Get help and information from our Caring Medical staff

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References

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