Austin summarizes the latest hip osteoarthritis CPG, highlights some of the changes from the previous version, and explains one of the more surprising recommendations.
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Austin summarizes the latest hip osteoarthritis CPG, highlights some of the changes from the previous version, and explains one of the more surprising recommendations.
Use code FIELDGUIDE for 40% off a MedBridge subscription.
Support the podcast and get study guides and bonus episodes at Patreon.com/physiofieldguide.
Find more resources and subscribe to practice questions at PhysioFieldGuide.com.
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.
To recap:
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:
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