Rio Bravo qWeek by Rio Bravo Family Medicine Residency Program

November 15, 2024 Episode 180: Pediatric Hip Pain

Episode 180: Pediatric Hip Pain

Future Dr. Pena-Brockett explains the differential diagnosis in a 14-year-old patient who has a new onset of left hip pain. Dr. Arreaza adds comments and explains toxic synovitis.

Written by Natalie Pena-Brockett, MSIV, California Health Sciences University. Comments by Hector Arreaza, MD.

You are listening to Rio Bravo qWeek Podcast, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California, a UCLA-affiliated program sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. This podcast was created for educational purposes only. Visit your primary care provider for additional medical advice.

Having a limping kid can be terrifying. Many questions may cross your mind: Is this a permanent damage? What is going on here? Where is the pain located? Do I need to send this child to the hospital? Today, hopefully, we can help you ease some of your fears.

Case: This is a 14-year-old boy with no past medical history, no trauma, presents to the family medicine clinic with a complaint of left-sided hip pain. Mom notes that her son has been limping for the last week and complaining of pain in his left hip and knee when he walks. He has never experienced this pain before this week. He does not take any medications. Physical exam: He is afebrile and all of his vitals are within normal limits. On exam, you note that his BMI is at the 90th percentile (overweight), and has an antalgic gait where he is favoring the right side and has tenderness on his left groin. His left foot is turned outward while standing up straight. His left knee has negative findings on specialized tests, but he has restricted movement of the left hip.

Discussion: This is a common topic that you will see on board exams or limping into your office. Although pediatric hip pain may seem like a benign musculoskeletal concern, taking the time to take a complete history and perform a thorough physical exam is critical to assess the severity of the patient’s concern.

Physical Exam for Pediatric Hip Pain.

Observation: Every physical exam begins the moment you first see the patient. This allows you to gauge the patient’s comfort level, the natural stature, length, and positioning of the patient’s extremities, skin changes, gait, and ability to bear weight.
Palpation: In medicine, our hands are one of our greatest tools for evaluating patients, especially those with musculoskeletal concerns. This is the time to palpate the area for any tenderness or gross deformities of the pelvis, hip, knee, or leg.
Special Tests: In the world of MSK, we have all sorts of tests to evaluate the range of movement of our joints and tendons. When specifically evaluating the hip, the most common are the FABER(flexion, abduction, external rotation),test to assess the sacroiliac joint, Ober’s Test to assess the iliotibial band, and Straight Leg Raise to assess for lumbar radiculopathy.

Legg-Calve Perthes Disease

-Legg-Calve Perthes disease is an idiopathic avascular necrosis of the femoral head.

-It is most commonly observed in patients between the ages of 2-12 years and in a higher ratio of males to females 1.

-It often manifests as an atraumatic limp with limited movement in abduction and internal rotation.

-X-ray imaging may demonstrate a widening of the joint space and sclerosis of the femur, and MRI will confirm osteonecrosis of the femoral head.

-Early diagnosis is key to minimizing the risk of developing osteoarthritis of the hip.

-The goal of treatment is to maintain the shape of the femoral head and the range of motion of the hip.

-The first-line treatment includes managing pain with NSAIDs, limiting weight-bearing activity, and physical therapy for range of motion.

-If the disease progresses, bracing and casting can be used to retain the femoral head within the acetabulum to keep the shape and integrity of the femoral head. In more serious cases, a surgical osteotomy may be done to cut and realign the bones.

Developmental Dysplasia of the Hip (DDH)

-Developmental Dysplasia of the Hip (DDH) is a pediatric condition that results in unilateral or bilateral instability of the hip due to the abnormal development of the acetabulum or femur.

-This is most commonly seen in newborns, especially those which develop in a breech position.

-These patients often present with a shortened leg or asymmetric gluteal creases and a Trendelenburg gait when walking.

-The Trendelenburg gait is an abnormal gait caused by weak hip abductor muscles. The person's trunk shifts over the affected hip during the stance phase of walking and away from it during the swing phase, making it look like the person is missing steps or limping.

-On physical exam, hip joint laxity can be evaluated with the Ortolani and Barlow maneuvers to apply pressure to the proximal femur to assess dislocatability of the hip joints. These maneuvers would both be considered positive if a “clunk” is felt over the hip as this means that the hip is dislocated with pressure. Due to the patient's age usually being under 6 months old, ultrasound is the most common imaging modality to confirm the diagnosis, otherwise, an X-ray can be used.

-The treatment in patients under 18 months old, a Pavlik Harness is often used to treat patients to maintain the placement of the hip within the acetabulum.

-Patients between the ages of 18 months and 9 years old, are most often treated with open or closed reduction of the hip.

-There is generally less success in reduction treatment of children older than 9 years old as they have likely developed femoral head deformities and are at greater risk of osteonecrosis.

-Children with DDH should continue to be monitored with regular imaging to evaluate for complications. These patients should also be made aware that they are also at increased risk of requiring a hip replacement, especially if their treatment included a reduction. 2

Slipped Capital Femoral Epiphysis (SCFE)

-Slipped Capital Femoral Epiphysis (SCFE) is one of the most common pediatric hip pathologies in which the capital femoral epiphysis is anterolaterally displaced from the femoral neck.

-Although slightly more common in males than females between the ages of 10 to 16, the greatest risk factor for an SCFE is childhood obesity 3.

-Common symptoms include an insidious onset of unilateral hip pain and a change in gait due to the displacement of the hip from the acetabulum. In some instances of chronic SCFE, some patients will experience ipsilateral knee pain due to compensation.

-A SCFE can be evaluated with an AP radiograph which will demonstrate a widened physis in the early stages or the classic “slipped ice cream cone sign” which is the posterior displacement of the femoral epiphysis.

-Management of a SCFE includes limiting weight-bearing activities as well as screw fixation by an orthopedic surgeon to stabilize the hip.Patients should consider pinning the contralateral hip due to increased risk of developing a future SCFE. Early diagnosis is critical as untreated SCFE can lead to osteonecrosis.

Osgood-Schlatter

-Osgood-Schlatter is a repetitive-use pediatric condition as a result of traction to the growth plate of the tibial tubercle.

-This pathology is most common in male children between the ages of 9 to 14 years old 4.

-Active athletes or children with rapid growth spurts are at greater risk of developing Osgood-Schlatter than non-active children.

-These children often present with an achy knee pain that can lead to a unilateral limping gait. On physical exam, these patients often have a bony prominence over the tubercle that is tender to palpation with greater tenderness over the patellar tendon.

-The knee will have full range of motion and stability, but will likely have a warmth and erythema over the knee. Imaging of the knees can have nonspecific findings and diagnosis is made clinically.

-For management, it is recommended that children continue their regular activities and rest with NSAIDs for pain management as needed 5. Physical therapy can be prescribed to prevent deconditioning as this can result in recurrence or additional injuries.

Arreaza: It seems like the pain is more localized to the knee, but it can be referred to the hip. If you have tenderness on the tibial tubercle, you got the diagnosis.

Juvenile Idiopathic Arthritis (JIA)

-Juvenile Idiopathic Arthritis (JIA) is a systemic rheumatologic condition in children that often presents as a polyarticular pain. The onset of disease is often bimodal with peaks between 2 to 5 years old and 10 to 14 years old. 6

-Patients will often complain of minor symmetric joint pain and stiffness until an infection causes an inflammatory reaction that exacerbates the joint pain or can increase joint involvement. Small joints are the most likely to be involved, but hips and knees can also be affected.

-Lab evaluation will demonstrate inflammation with an elevated ESR, low hemoglobin, and a positive ANA.

-Disease management starts with NSAIDS for pain control and can escalate to immunosuppressive measures for moderate disease7.

Toxic Synovitis

-Toxic synovitis, also known as transient synovitis, is the leading cause of acute hip pain and limping in children aged 2–12, more commonly affecting boys.

-This self-limited inflammatory condition, often confused by its name as "toxic," has no relation to a toxic state. It typically arises after an upper respiratory or other viral infection (e.g., rubella or coxsackie virus).

-Children with toxic synovitis may show mild to moderate hip pain, limp, and keep their hip in abduction and external rotation. Movement is usually possible within a limited range, and weight-bearing is often maintained.

-Evaluation: A thorough history and physical exam are key, as laboratory tests like CBC, ESR, and CRP are often normal, mainly used to rule out other conditions like septic arthritis. X-rays typically show no abnormalities, although small changes may appear. Ultrasound can help detect joint effusion and rule out septic arthritis if no effusion is present.

Arreaza: DDX: DDH, SCFE, Osgood Schlatter, and toxic synovitis.

Osteopathic Manipulative Treatment in Pediatric Hip Pathologies

Sacroiliac Articulatory Technique- this is a technique in which you move the joint into an out of its barrier to reduce restriction and improve movement
Counterstrain of Tender points (psoas, piriformis, hip adductors)- in this technique we shorten the muscle to decrease tension. This allows the muscle to increase blood lymphatic flow to reduce nociceptive and proprioceptive activity of the muscle
Balanced Ligamentous Tension of the Innominate- with this technique, we manipulate the joint in a way that moves the ligaments into neutral position so that there is balance in all planes of motion. The goal is to again release tension within the muscles and the joint

Clinical Decision Making

Now that we have covered the most common differential diagnoses for pediatric hip pain, let’s revisit our patient presentation and identify the key characteristics to determine which diagnosis he most likely has.

The patient is 14 years old. This makes DDH and Legg-Calve Perthe less likely, and SCFE more likely.
He has been complaining of symptoms for 1 week, which indicates that is not likely a chronic condition. This makes DDH and Osgood-Schlatter less likely.
The patient has never experienced joint pain like this before. This makes JIA, DDH, and Osgood-Schlatter less likely.
The patient is overweight. This makes SCFE more likely.
The unilateral hip tenderness and no knee pain. This makes Osgood-Schlatter and JIA less likely.
The patient has antalgic gait and limited internal rotation of the foot. This makes Legg-Calve Perthes and SCFE more likely.

Now when we take the epidemiological factors, the history of the present illness, and the physical exam findings into account, this patient’s presentation best aligns with a SCFE. We would order a bilateral AP and Frog-leg views of the hips. If either imaging shows a widened physis or the classic “ice cream cone sign”, this is when we would start the referral process for an orthopedic surgery consultation for internal fixation. As family medicine physicians, we would give instructions for strict non-weight bearing activities and analgesics or anti-inflammatories for pain management.

Keep in mind some of the DDX: Calve Legg-Perthes disease, Developmental Dysplasia of the Hip (DDH), Juvenile Idiopathic Arthritis (JIA), Osgood Schlatter, toxic synovitis, and Slipped Capital Femoral Epiphysis (SCFE). Hopefully, the next time you have a pediatric patient present with a complaint of hip pain, you’ll feel more comfortable evaluating and working up the case.

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This week we thank Hector Arreaza and Natalie Pena-Brockett. Audio editing by Adrianne Silva.

Even without trying, every night you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you, send us an email at [email protected], or visit our website riobravofmrp.org/qweek. See you next week!

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References:

Osteonecrosis of the femoral head / Legg-Calvé-Perthes disease | Time of Care. Accessed October 27, 2024. https://www.timeofcare.com/osteonecrosis-of-the-femoral-head-legg-calve-perthes-disease/
Scott EJ, Dolan LA, Weinstein SL. Closed Vs. Open Reduction/Salter Innominate Osteotomy for Developmental Hip Dislocation After Age 18 Months: Comparative Survival at 45-Year Follow-up. J Bone Joint Surg Am. 2020;102(15):1351-1357. doi:10.2106/JBJS.19.01278. https://europepmc.org/article/med/32769602
Perry DC, Metcalfe D, Costa ML, Van Staa T. A nationwide cohort study of slipped capital femoral epiphysis. Arch Dis Child. 2017;102(12):1132-1136. doi:10.1136/archdischild-2016-312328. https://pubmed.ncbi.nlm.nih.gov/28663349/
Haines M, Pirlo L, Bowles K-A, Williams CM. Describing Frequencies of Lower-Limb Apophyseal Injuries in Children and Adolescents: A Systematic Review. Clin J Sport Med. 2022;32(4):433-439. doi:10.1097/JSM.0000000000000925. https://pubmed.ncbi.nlm.nih.gov/34009802/
Wall EJ. Osgood-Schlatter disease: practical treatment for a self-limiting condition. Phys Sportsmed. 1998;26(3):29-34. doi:10.3810/psm.1998.03.802. https://pubmed.ncbi.nlm.nih.gov/20086789/
Oberle EJ, Harris JG, Verbsky JW. Polyarticular juvenile idiopathic arthritis - epidemiology and management approaches. Clin Epidemiol. 2014;6:379-393. doi:10.2147/CLEP.S53168. https://pubmed.ncbi.nlm.nih.gov/25368531/
Beukelman T, Patkar NM, Saag KG, et al. 2011 American College of Rheumatology recommendations for the treatment of juvenile idiopathic arthritis: initiation and safety monitoring of therapeutic agents for the treatment of arthritis and systemic features. Arthritis Care Res (Hoboken). 2011;63(4):465-482. doi:10.1002/acr.20460. https://pubmed.ncbi.nlm.nih.gov/21452260/
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