Hip Osteoarthritis CPG (2017 Update)

Austin summarizes the latest hip osteoarthritis CPG, highlights some of the changes from the previous version, and explains one of the more surprising recommendations.

Transcript

Hello and welcome back to the  OCS field guide podcast. Today we are covering the 2017 revision of the hip pain and mobility deficits - hip OA CPG. Before we jump in to the episode I do want to remind you of our Patreon group where you can engage with us directly with questions, access exclusive content and study aids for high value information areas, join live study sessions, and access recordings of previous study sessions. Your support through Patreon allows us to keep the podcast pretty much ad-free (except for this shameless plug), and makes us able to carve out time from our families and full time jobs to make this podcast. Thanks to all of you for making this possible!

Without further self-promotion, let’s talk about hips that don’t often lie - ones with OA. 

We’ll start with a quick overview of the most boring part of all of the CPGs - impairment/function-based diagnosis. Hip OA is the most common cause of hip pain in older adults. The pathoanatomic features of hip OA involve articular changes including focal lesions and decreased cartilage volume as well as changes to subchondral and periarticular bone. Presence of acetabular retroversion is related to the development of hip OA.The natural history of hip OA is not completely understood, but we know it involves changes both inside and outside the joint resulting in loss of joint space, development of osteophytes, subchondral sclerosis and cysts, loss of joint range of motion, and weakness in the muscles around the hip joint. Total hip arthroplasty is the most common surgical intervention for end-stage hip OA, but there is no consensus on timing of hip OA. Non-surgical intervention should be attempted, and it is suggested that non-surgical intervention has failed if there is not a significant reduction in symptoms such as improvement of 20-25% on the WOMAC. The progression of hip OA varies widely from patient to patient and thus therapists should monitor objective measures such as ROM, strength, pain, outcome score, joint space width, and Kellgren Lawrence grades to aid in decision making regarding timing or necessity of surgery. 

 The risk factors to look out for hip OA include: increased age, history of hip developmental disorders such as dysplasia, previous hip joint injury, reduced him ROM especially in internal rotation, presence of osteophytes, lower socioeconomic status, higher bone mass, and higher BMI. Here is the part to be sure to remember: the diagnosis of hip OA and ICF classification of hip OA should be made with the following criteria: patient over the age of 50, moderate anterior or lateral hip pain during weight-bearing activities, morning stiffness less than 1 hour, hip internal rotation range of motion of less than 24 deg, or hip internal rotation and hip flexion of 15 degrees less than the non-painful side, and/or hip pain provoked with passive hip internal rotation. 

The differential diagnosis section is trash in this CPG and pretty much says if they do not present with this presentation and/or don’t improve with appropriate interventions you should consider other diagnoses. Thanks. So I’ll throw my own recommendations here, I would be looking out for the other common hip pain in older adults (which David has covered in another podcast) greater trochanteric pain syndrome whatever you want to call it today. Especially because both can have pain at the lateral hip with weight bearing activity and occur more in older adults. It would also be relatively common to have someone with radiographic evidence of hip OA to be relatively asymptomatic for their hip OA, but have a very symptomatic greater trochanteric pain syndrome. I’m sure we’ve all seen the patient that got a hip replacement for their lateral hip pain which was still very present following since it was actually trochanteric pain. 

Again, for classification of hip pain with mobility deficits, we are looking for a combination of age over 50, moderate anterior or lateral hip pain with weight bearing (but not isolated trochanteric pain), morning stiffness less than 1 hour, hip IR less than 24 deg, or IR and flexion 15 deg less than non painful side, and/or increased hip pain with passive IR. 

For imaging, we are primarily looking at radiographs for diagnosing and assess progression of hip OA. In radiographs we are looking for level of joint space narrowing, presence of osteophytes, and subchondral sclerosis or cysts. 

Let’s move on to examination. 

Our other favorite section is self-reported outcome measures. They recommend using measures that include pain, functional impairment, activity limitation, and participation restriction as always. They recommend the WOMAC, the pain sub scale for pain and the physical function sub scale for activity limitation and participation restriction. The WOMAC is by far the most well researched tool, so I would learn this one. There it is a measure of disability, so higher scores are worse and is expressed as a percentage typically, though the measure is out of 96, trying to be complicated. For the tool as a whole, the MCID ranges from 12-22%. So if a patient decreases their score an amount anywhere in that range you can be confident IMPROVEMENT in a condition has been made. Highlight the WOMAC as one of the measures that you want to be lower rather than higher. The other tools they recommend for the hip OA pain are the Brief pain inventory, pain pressure threshold, and the VAS. For activity limitation, other than the WOMAC, they recommend the Hip disability and osteoarthritis outcome score or HOOS, the LEFS, and Harris hip score. For all three of these, higher scores mean better function and symptoms. The only MCID I would memorize from those is the LEFS which is a 9 point change out of 80.  They give an A-level recommendation for the use of any of these, and specifically having both a pain and activity limitation measure.

Now for physical performance measures. They recommend a number of different performance measures. I would not personally spend time knowing all the MCDs and cut scores for all of them, but do know WHAT each test is and what it is focusing on most, such as balance, direction change, strength and endurance, speed, etc. They  give an A recommendation to use measures such as the 6-minute walk test, 30-second chair stand, stair measure, timed up-and-go, self-paced walk, timed single-leg stance, 4-square step test, and the step test. If I were writing a question on this information, I would present a case and a partial exam that included a couple of these, and then ask based on the case which other performance measure would be most appropriate to add. You’d be looking to add the measure that best fit the history, and gave a more complete picture of the patient. For instance, if they already had 30-second chair stand and gait speed, I probably wouldn’t choose the TUG. You would be better to pick something like Timed single leg stance, which would obviously capture static balance, the 4-square step test which would capture direction change and dynamic balance, or the step test which would capture stepping up. Your selection would then be based on what the history information made you think was most important for the case. They also give a separate A-level recommendation for using a balance measure to predict fall risk in this population. Recommended balance tests include the Berg Balance scale, 4-square step test, and single-leg balance. The Berg balance scale is one to know for sure. The cut score for fall risk is 50 or below, and 40 or below has nearly 100% fall risk, so these people have to be on an assistive device. 

For objective examination they give an A level recommendation that over an episode of care, you should document the FABER or Patrick’s test and passive hip ROM and muscle strength in all planes. 

They go on to give a best practice recommendation on the minimum that should be included in the whole exam for all patients with hip OA for standardization, which clues us in on what they think is most important. They say to use:

-WOMAC physical function sub scale for self-report measure

-For physical performance they say to at least include: 6 minute walk test, 30-sec chair-stand, TUG, and the stair measure (which is timing going up and down 9 steps)

-And then for physical impairment measure at least: ROM and strength for IR, ER, FL, EXT, ABD, and ADD, 

-pain rating with NPRS

-and asses joint irritability with the FABER test

Now it’s time for interventions. I have this content structured in order of strength of recommendation, with the strongest first. 

1. Manual Therapy gets an A-level recommendation. Manual therapy should be used for patients with mild-moderate hip OA that have impairments and should consist of thrust non-thrust, and soft tissue mobilization. Dosage (I love it when they put dosage in here) can range from 1-3x/week over 6-12 weeks. This is strengthened from a B level recommendation in the 2009 CPG, which was also limited to being used for short-term benefit. Not only is manual therapy strengthened to an A, but they do not constrain this recommendation to short term benefit only. However, they do include that as hip motion improves, clinicians should add exercises including stretching and strengthening to augment and sustain gains in ROM, flexibility and strength. Which brings us to…
2. Flexibility, Strengthening, and endurance exercise - which gets an A-level recommendation (which is also strengthened from a previous B). Note that this exercise recommendation is specific to flexibility, strength, and endurance, and there is a separate recommendation for functional, gait and balance training. The recommendation states, “clinicians should use individualized flexibility, strengthening, and endurance exercises to address impairments in hip range of motion, specific muscle weaknesses, and limited thigh (hip) muscle flexibility.” This can be given in group-based setting, but effort needs to be made to individualize to each patient’s relevant physical impairments. Proper dosage should range from 1-5x/week for 6-12 weeks.
3. Patient education combined with exercise and/or manual therapy which receives a B-level recommendation. They recommend education include teaching activity modification, exercise, supporting weight reduction when overweight, and methods of unloading the arthritis joints. Note that this only has significant effect when used in combination with exercise and/or manual therapy. 
4. Modalities. Our other B-level recommendation is actually FOR ultrasound, so put this on your very short list of conditions where ultrasound is recommended. Clinicians MAY use ultrasound at 1 MHz, 1W/cm2. Here’s the key though, you have to do it for 5 minutes each on the anterior, lateral, and posterior hip (so not just the 7 minutes plus setup to get your billed time in, *cough cough*) in addition to exercise and hot packs for short term management of pain and activity limitation. However, the recommended dosage based on the one strong study that gets us this recommendation is 10 sessions over a 2 week period. So if you can hit is every week day for 2 weeks, with hot packs and exercise, go for it! Maybe it is effective at a lower dosage, those studies just haven’t been done. 
5. The first C-level recommendation is for functional, gait, and balance training. They recommend clinicians should provide impairment-based training for functional movements, gait, balance, and proper use of assistive devices when when limitations in these areas are observed and documented. There is a second C-level recommendation in this category specifically recommending that prescription of these therapeutic activities should be based on the patients individual values, activity participation, and daily functions. This is based on a study that showed long term improvement in self-reported physical activity level when they had rehab focused on a specific favorite recreational activity. So the takeaway from both of these is include functional training, but make it very specific to the patients impairments, values, and needs. 
6. Now for weight loss, which gets a C-level recommendation. For patients with hip OA who are obese or overweight, clinicians should collaborate with physicians, nutritionists, or dietitians to support weight reduction. This is in addition to providing exercise intervention. 

To recap: 

• We are going to rule in patients to hip OA who have anterior and lateral pain with weight bearing, morning stiffness less than an hour, hip IR ROM less than 24 deg or IR and flexion 15 deg less than the non-sinful side, increased hip pain with passive hip IR, and absence of history and presentation that would be inconsistent with hip OA.
• With these patients we should use self reported measures like the WOMAC, LEFS, HOOS, and HHS, and we should use activity based testing such as the BERG, TUG, stair measure, self-paced walk test, 4-square step test, step test, timed single leg stance, 30-second chair stand, and 6 minute walk
• We should get impairment measures including the FABER and SCOUR tests, active and passive ROM in all planes, hip abduction and extension strength and motor control. 
• We should treat these patients with a focus on Manual therapy and flexibility, strengthening, and endurance exercise, all of which get an A-level recommendation with dosage recommendation of 6-12 weeks with 1-3x/week with manual therapy and 1-5x/week for exercise. We can also use patient education combined with manual therapy and exercise gets a B-level recommendation. Oddly enough we can also do ultrasound which has a B-level recommendation FOR, provided you spend a crazy amount of time doing it. Finally, especially where indicated, we can do functional training/gait/balance and collaborative weight loss approaches which both get a C. 

Let’s finish up with a practice question: 

A 60-year-old female presents to physical therapy for treatment of L hip pain. She reports 3-year history of hip pain without any mechanism of injury. She has pain with prolonged sitting, walking, and going up stairs. Her pain is worse when she first gets up in the morning or after being inactive for more than 30 minutes.

Objective examination reveals:

• L compensated Trendelenberg gait
• L hip MMT 4-/5 and painful for abduction, external rotation, and extension

Which of the following additional findings would most decrease suspicion of hip OA?

A. History of hip dysplasia
B. L hip IR ROM 30 deg
C. BMI of 24
D. Lateral hip pain with weight-bearing