MSK

Pedi MSK Potpourri

1/21/26

#1

A 12-year-old male basketball player presents to your clinic with the complaint of three months of anterior knee pain. He does not recall a specific injury, but states that he has noticed it getting worse over the last two weeks. The pain is worse while he is playing and improves on his days off. He denies any swelling, fever, locking, or giving way of the knee. Physical exam reveals no effusion, normal ligament exam, positive tenderness to palpation at the inferior pole of the patella, and an intact extensor mechanism. Radiographs reveal bony fragmentation at the inferior pole of the patella. Which of the following is correct regarding treatment of this patient?

Multiple Choice

#1 Which of the following is correct regarding treatment of this patient?

• (A) Obtain an MRI of the knee to evaluate for avulsion of the patellar tendon

• (B) Place the patient in a knee immobilizer in full extension

• (C) Recommend relative rest with pain-free activity and gradual return to full sport participation as he improves

• (D) Refer the patient to orthopedic surgery to consider operative repair

• (E) Restrict all activity for six weeks followed by return to full sport participation

Correct answer: C

This patient has apophysitis at the inferior pole of the patella. It is most common in athletes involved in jumping sports between the ages of 10 and 15 years. The mainstay of treatment is modification of activity with relative rest. They may participate in activities that do not exacerbate the pain. Return to sports should be gradual and pain free. For uncomplicated cases, such as the case described, MRI is unhelpful and not indicated. Full rest or immobilization are very rarely needed, and reserved for severe cases where there is pain with all activities, or significant concern for avulsion fracture. Surgery is not indicated in uncomplicated disease. The condition resolves spontaneously, usually in 12 to 18 months, which correlates to the time of peak growth in adolescents.

Multiple Choice

#3 Which of the following is most accurate regarding infrapatellar fat pad pathology?

• A) Infrapatellar fat pad irritation, which is frequently confused with patellar tendinopathy, is often associated with overextending the knee when running downhill

• (B) History rarely helps differentiate patellar tendinopathy from fat pad irritation since they both present after a forceful extension maneuver

• (C) Infrapatellar fat pad pathology is unresponsive to physical therapy and most cases require surgical management

• (D) Taping and lower limb training increases patellar valgus alignment, reduces patellar height, and results in further fat pad inflammation, often exacerbating patient symptoms

#3 Correct answer: A

Fat pad irritation is an underdiagnosed condition. The infrapatellar fat pad is also known as Hoffa's fat pad. It is frequently confused with patellar tendinopathy and onset is associated with a rapid extension of knee such as overextending the knee when running downhill. Patellar tendinopathy is more often associated with eccentric loading, such as increased hill or stair descent in running. Since the pain in both conditions involves the inferior patellar region, differential diagnosis can be difficult. Answer B is incorrect because the patient's history may help to differentiate patellar tendinopathy from fat pad irritation. Patients with patellar tendinopathy should have a history of eccentric loading of the quadriceps muscle such as running downhill, whereas a patient with a fat pad irritation presents after forceful knee extension.

On exam, patellar tendinopathy may present with pain with loaded knee flexion. Patients with infrapatellar fat pad irritation may have pain with the following maneuver: pressure is applied to either side of the patellar tendon with the knee in 60 degrees of flexion, and pressure is maintained while the knee is extended. Reproduction of pain is a positive test. Answer C is incorrect since infrapatellar fat pad pathology is usually successfully managed with physical therapy. Physical therapy aims to unload abnormally inflamed tissue, both passively through taping and actively by improving lower extremity mechanics, which involves optimizing hip muscle control as well as foot function, which improves symptoms. Answer D is incorrect because physical therapy with taping to unload the fat pad and lower limb training has been shown to increase patellar varus alignment, increase patellar height and alter medial drift of the patella, as well as decrease fat pad inflammation and volume.

#4

A 22-year-old runner presents with groin pain radiating to the thigh which coincided with an increase in her running mileage. She is now unable to run due to the pain. On exam there is normal range of motion. Pain is reproduced with FADIR and single leg hop test. Plain films do not show visible pathology. Given your clinical suspicion, you order an MRI, which shows a small labral tear and increased linear low T1 and low T2 signal intensity through the cortex representing a fracture line in the superior portion of the femoral neck. What is the next best step?

Multiple Choice

#4 What is the next best step?

• (A) Physical therapy prescription to work on biomechanics

• (B) Hip arthroscopy for labral tear

• C) Surgical referral for pin fixation of the femoral neck

• (D) Non-weight bearing with crutches for four to six weeks

#4 Correct answer: C

_{This patient has a tension-side stress fracture of the femoral neck and is at risk of catastrophic fracture if untreated. Stress fractures of the femoral neck make up approximately 10% of all stress fractures. On physical exam, the pain is most often reproduced with internal rotation and passive range of motion at the hip and described as presenting typically in the anterior thigh or hip with weight-bearing. A positive hop test is positive in at least 70% of radiologically confirmed stress fractures. Tension-type fractures (superior femoral neck) carry a high risk of displacement and non-union; therefore, surgical fixation is the treatment of choice. Despite surgical intervention, there is still a high risk of non-union and avascular necrosis of the femoral head.}

The remaining answer choices are not appropriate initial management options for tension-side femoral neck stress fractures. Compression-type fractures (inferior femoral neck) can be treated conservatively with non-weight bearing and graduated return to activity. Labral tears are frequent findings on imaging in athletes. In this patient, the pain is likely secondary to the fracture and must not be missed when evaluating hip pain in the active athlete. Underlying biomechanical abnormalities must be addressed in the rehabilitation protocol for both injuries, but physical therapy is not a substitute for surgical management in tension-sided stress fractures

#5

A 13-year-old male Pacific Islander is seen in the clinic with his parents complaining of right hip pain a day after playing rugby. He locates his pain over the anterior aspect of his thigh, and you appreciate an antalgic gait. His mom states that she thinks the patient just pulled his groin. He has been limping the last few days. You order x-rays and confirm your clinical suspicion, diagnosing the patient with a stable, right slipped capital femoral epiphysis (SCFE). What is the best plan of action?

Multiple Choice

#5 What is the best plan of action?

• (A) Surgical fixation with a single screw and prophylactic fixation of the contralateral side

• (B) Surgical fixation with a single screw

• (C) Allow full weightbearing if the patient can tolerate it, but hold him from rugby

• (D) Begin rehabilitation course with focus on strengthening; if not improving, refer to an orthopedic surgeon

#5 Correct Answer: B

In situ fixation with a single screw is the treatment of choice when stability of SCFE is appreciated. Prophylactic surgical fixation treatment of the contralateral side is controversial. It may be reserved for those at high risk of slippage, but is currently not recommended. Once the diagnosis of SCFE is made, the patient is instructed to be non-weightbearing on crutches or a wheelchair. Full ambulation may cause further slippage or cause the femoral head to become unstable. The diagnosis of SCFE is not attributed to lack of strength or functional stability, so physical therapy has no benefit. Instead, obesity, a recent growth spurt, and endocrine disorders have been associated with SCFE.

#6

An 11-year-old female presents with anterior knee pain with jumping. Lateral x-rays show a lucency in the patella. Growth plates are open. Subsequent MRI shows intact articular cartilage over a bony loose body. What is the next step in management?

Multiple Choice

#6 What is the next step in management?

• (A) Activity modification and close follow-up

• (B) Surgical drilling

• (C) Continue with regular activities and recheck in six months

• (D) Formal physical therapy

#6 Correct answer: A

_{This patient has osteochondritis dissecans. In adolescents with open growth plates and intact, stable lesions, non-surgical management with activity modification is first line treatment, not surgery. If conservative treatment fails, usually after at least six months, then surgical intervention becomes an option. Lesions in atypical places such as the patella and lateral femoral condyle have less predictable healing patterns then typical lesions at the medial femoral condyle. Since this is an atypical location, it is at higher risk to require surgery and requires close follow up. Lesions that are unstable, with breeches in the articular cartilage, are immediate surgical candidates. If she was asymptomatic, then simple observation without a change in activity levels, with close follow-up may be an option but since she is symptomatic, she should decrease running and jumping activities, making Answer C incorrect. There is no evidence that early physical therapy helps with recovery.}

#8

A 15-year-old male baseball player presents to the office with lateral elbow pain. He denies any recent acute injury. He has pain only with throwing. Physical exam reveals a glenohumeral internal rotational deficit, full range of motion of the elbow, no point tenderness to palpation and normal elbow strength. X-rays are pictured below. What is his diagnosis?

Multiple Choice

#8 What is his diagnosis?

• (A) Osteochondritis dissecans

• (B) Lateral epicondylitis

• (C) Little league elbow

• (D) Medial epicondylitis

#8 Correct answer: A

He has osteochondritis dissecans of the capitellum. In the x-ray, there is a lucency in the capitellum consistent with focal bone injury. In the developing elbow, the major vascular supply to the capitellum is via end arterioles. This injury is thought to be caused by repetitive microtrauma to the blood vessels around the capitellum, resulting in a focal avascular necrosis of the capitellum. Adolescent gymnasts and pitchers are particularly at risk for this injury. Collateral circulation about the elbow is usually complete by age 19, making this injury rare after adolescence.

Lateral epicondylitis should present with focal pain to palpation and pain with resisted wrist extension and/or resisted third digit extension. Little league elbow is incorrect because this describes an overload to the medial, not the lateral elbow. Little league elbow is a syndrome that encompasses altered growth of the medial epicondyle (medial epicondylar apophysitis) and traction apophysitis. Medial epicondylitis is an overuse tendinopathy and is incorrect because it occurs on the medial side.

#9

A 12-year-old female ballet dancer presents with left second metatarsal pain. Physical exam is notable for pain over the second metatarsal head and shaft. Ankle dorsiflexion is zero degrees with the knee in full extension. She has pain walking on her tip toes and with single leg hopping. X-rays are shown below. What are the next most appropriate steps in management?

Multiple Choice

#9 What are the next most appropriate steps in management?

• (A) Diagnose Freiberg's infraction and immobilize the foot

• (B) Order an MRI to look for stress fracture

• (C) Prescribe physical therapy for intrinsic foot strengthening and ankle flexibility

• (D) Add a metatarsal pad to her shoes and allow her to continue dancing

#9 Correct answer: A

The x-ray shows some flattening of the metatarsal head consistent with Frieberg’s infraction. Frieberg’s infraction is likely a multifocal process (similar to Perthes disease in the hip) which progresses to a focal avascular necrosis of the metatarsal head, usually the second or third. Classically this affects adolescent females. Early detection and treatment are associated with excellent outcomes. Treatment is unloading of the metatarsal head, either with post op shoe, cast or limited weight bearing. Occasionally a metatarsal pad may be used to help unload the metatarsal head, but this would be in conjunction with activity restriction.

Answer D is incorrect because she should not be allowed to return regular dance activity at this time. Outcomes with late detection and treatment with surgery are suboptimal compared to early treatment. Answer B is not correct because MRI is not needed to evaluate for a stress fracture. If there is doubt about the diagnosis or there is significant metatarsal head collapse, then MRI may be appropriate. Answers C and D are incorrect because at this time, she needs to allow the metatarsal head to re-establish blood flow and heal, so unloading the bone and rest are needed, not physical therapy or a metatarsal pad so she can continue to dance. After recovery, physical therapy and/or a metatarsal pad may be helpful.

Multiple Choice

#10 You are caring for a 16-year-old male with sickle cell trait. The patient would like to participate in football for the upcoming season. Which of the following is correct regarding his risk for participation?

• (A) Sickle cell trait poses no health risk for sport participation

• (B) Sickle cell disease is an absolute contraindication to sport participation

• (C) Participation in collision sport is associated with specific increased risk in patients with sickle cell disease

• (D) The patient should be counseled about increased risk in hot weather

#10 Correct answer: D

Sickle cell disorders are associated with an increased risk of crisis during episodes of dehydration and while at altitude. Because the sickle hemoglobin does not distribute oxygen as efficiently as normal hemoglobin, dehydration and exercise at altitude can precipitate a sickle crisis. This is true for both patients with sickle cell disease and those with sickle cell trait. Although there is an increased risk of crisis during exercise, patients with sickle cell disorders should be encouraged to exercise for general health as well as improved oxygen-carrying capacity that is realized in well-conditioned individuals. Except for risks associated with dehydration and altitude, participation in collision sports does not impart increased risk to the athlete.

#11

You are seeing a 17-year-old male in your office with the complaint of knee pain. He reports feeling a dull ache in his left knee that started after a minor twisting injury one week prior. He denies any locking or instability. The pain is worse with squatting and going up stairs. He occasionally feels a popping sensation. On exam, you palpate a taught band of tissue just medial and inferior to the patella on his left knee. Palpating this band reproduces his pain. He has no other points of tenderness during palpation but does have mild pain with McMurray's test. No joint effusion is present. His Lachman, patellar apprehension, and patellar compression tests are negative. What is the most likely diagnosis?

Multiple Choice

#11 What is the most likely diagnosis?

• (A) Osteochondritis dissecans

• (B) Medial plica syndrome

• (C) Medial meniscus tear

• (D) Patellar subluxation

• (E) Patellar tendonitis

Correct answer: B

_{Plica syndrome (also known as synovial plica syndrome of the knee) is a constellation of symptoms related to inflammation/irritation of the plica. The plica is a normal anatomic structure of synovial tissue of the knee. It is thought to be a remnant of an embryologic tissue. The medial plica is most commonly affected in plica syndrome. The most common mechanism of medial plica syndrome is impingement by the femoral condyle during flexion of the knee. This causes an inflammatory reaction inside the knee. The repetitive impingement causes the plica to become thicker and stiffer. Diagnosis is difficult since symptoms often overlap with other conditions. Symptoms can include anterior/anteromedial knee pain, episodic pain, clicking, snapping, giving way, locking, catching, and aggravation of pain by activity, climbing stairs, and prolonged standing, squatting, or sitting. Exam classically is a taut articular band that reproduces the patient’s pain when palpated, without an intra-articular effusion.}

#11 Correct answer: B

Effusion not present. While the diagnosis is clinical, MRI can be useful to exclude other pathologies, but a negative MRI does not exclude plica syndrome since it may be difficult to see if it is lying against the synovial lining. Treatment typically begins with conservative management including stretching and strengthening the surrounding tissues, nonsteroidal anti-inflammatory drugs, activity modification, and bracing/taping. When symptoms are persistent for six months despite non-surgical management, surgical resection is an option. Osteochondritis dessecans, medial meniscus tear, ACL tear, and patellar subluxation will usually present with a joint effusion, along with additional exam findings, making Answers A, C and D incorrect. Patella tendonitis would cause tenderness to palpation over the patella tendon centrally and not medially making Answer E incorrect.

#12

A 16-year-old female lacrosse player presents with injury to her flexed knee during a game. She felt her knee give out while cutting and heard a pop. She is able to bear weight, but the knee is swollen and very painful. On exam there is a large effusion and a positive lateral apprehension sign. Collateral and cruciate ligaments appear intact on exam. MRI findings most consistent with her suspected injury include which of the following?

Multiple Choice

#12 MRI findings most consistent with her suspected injury include which of the following?

• (A) Lateral patellar retinaculum tear, medial femoral condyle contusion

• (B) Medial patellar retinaculum tear, medial patellar contusion

• (C) Medial patellar retinaculum tear, medial femoral condyle contusion

• (D) Medial patellar retinaculum tear, lateral patellar contusion

#12 Correct answer: B

This patient likely suffered a transient patellar dislocation. In this situation, the patella dislocates laterally over the femoral trochlea, injuring the medial patellofemoral ligament (alternatively termed the medial retinaculum), with the medial patellar border impacting with the lateral femoral condyle. The only correct combination of MRI findings provided are medial patellar retinaculum tear and medial patellar contusion. Hemarthrosis and effusion are often present acutely secondary to intraarticular ligament tears as well as bony contusions. Anatomical predispositions include generalized laxity, trochlear dysplasia, and patellar abnormalities

#13

A 13-year-old female soccer player presents to the sports medicine clinic complaining of three weeks of insidious onset bilateral anterior knee pain that worsens with running and improves with rest. She experiences occasional popping in the knees but has no swelling. Plain radiographs of the knees are normal for her age. On exam, you note bilateral mild genu valgum and pes planus. She is mildly tender to palpation on the medial patellar facet but nowhere else. There is no effusion. Range of motion and strength testing are normal. All ligaments are intact and there is no pain with McMurray exam. You ask the patient to stand and perform a squat jump. As she does so, you note that her valgus deformity drastically increases just before takeoff and when landing. Which of the following is the most appropriate counseling to give this patient regarding management of her condition?

Multiple Choice

#13 Which of the following is the most appropriate counseling to give this patient regarding management of her condition?

• (A) She should take non-steroidal anti-inflammatory drugs (NSAIDs) before activity and ice her knees after activity

• (B) She should seek consultation with an orthopedic surgeon regarding medial patellofemoral ligament (MPFL) reconstruction

• (C) She should begin a rehabilitation program focused on hip and quadriceps strengthening

• (D) She should find a different sport that doesn't cause her knees to ache

#13 Correct answer: C

This patient has patellofemoral pain syndrome (PFPS). PFPS is one of the most common diagnoses in a sports medicine clinic. The source of pain is not particularly well understood but is thought to be multifactorial in nature. Because weak hip abductors have been implicated in development of PFPS, rehabilitation programs focusing on hip strengthening can be effective for treatment. In this patient, an increase in valgus deformity with jumping suggests weak hip abductors.

Answer A is incorrect because while NSAIDs and ice can help with pain and are indicated adjunctive therapies, they do not address the underlying problem. Answer B is incorrect because this patient has not used conservative measures to address her pain. There are several operative interventions that can be performed based on radiographic and arthroscopic findings, but surgery is not an appropriate initial management strategy. Answer D will rarely be a correct answer in any clinical scenario. Some conditions may occur that will preclude an athlete’s participation in a particular sport, but a condition as benign as PFPS should not prompt a clinician to encourage discontinuation of a sport.

#14

An otherwise healthy eight-year-old boy with a BMI of 17 presents with right leg pain and limping for three weeks. He plays baseball but is currently not in season and has been swimming only for fun over the summer. He denies trauma, fevers, and has been feeling well. His knee exam is normal, but he has a preference for holding his right leg in external rotation, and you decide to order x-rays. X-rays of both hips demonstrate a normal left hip but sclerosis of the right proximal femoral epiphysis with a crescent sign. Your initial treatment plan should include which of the following?

Multiple Choice

#14 Your initial treatment plan should include which of the following?

• (A) Hip ultrasound

• (B) Hip injection

• (C) Physical therapy

• D) Bracing

• (E) Urgent surgery

#14 Correct answer: C

Hip disorders in children can present with a variety of pain locations and concerns. Pain can be noted in the sacral area, groin, hip, thigh, and/or knee. Patients can present with refusal to bear weight, a limp, and/or decreased motion. Once the origin of the pain is identified as the hip itself, by a detailed history and physical exam, the differential diagnosis list becomes much simpler. Given his gender (Perthes has a male-to-female ratio of four to one), his age (between four and ten), his body habitus (normal BMI), his lack of preceding trauma, his generally healthy status, his limping and external rotation on exam, and his x-ray findings (a crescent sign is associated with subchondral fractures), Legge-Calve'-Perthes disease is high on the differential diagnosis list. Perthes (the commonly shortened name) is an idiopathic avascular necrosis of the hip at the proximal femoral epiphysis. 

Treatment of Perthes begins with rest from aggravating activities and range of motion therapies, unlike SCFE which requires urgent surgery. The main complication of Perthes is osteoarthritis of the hip. Bilateral involvement of the hips in Perthes occurs in only 10% of patients; thus, the presence of bilateral disease should trigger a search for another etiology. Avascular necrosis of the hip can also be found in patients with chronic diseases, including blood disorders (ex. hemoglobinopathy, leukemia, coagulopathy) and other systemic disorders (ex. lupus, lymphoma). Ultrasound is not needed to make the diagnosis. Hip injections are not recommended for Perthes or other childhood hip conditions. Bracing is not a recommended treatment, and surgery is not recommended acutely

#15

A five-year-old boy presents to your clinic for evaluation of six weeks of insidious-onset foot pain. His mother reports that he intermittently complains of foot pain with activity and he occasionally limps or walks on the side of his foot. He points to the dorsal aspect of the medial midfoot as the location of his pain and his mother confirms that this is consistently the location of his pain. The boy has not had any unusual rashes or constitutional symptoms such as fever, fatigue or decreased appetite. He does not wake at night with pain. Inspection of the foot reveals no masses, nodules or swelling and joint range-of-motion is normal. Which of the following radiographic finding(s) would confirm your suspected diagnosis?

Multiple Choice

#15 Which of the following radiographic finding(s) would confirm your suspected diagnosis?

• (A) A large ossicle over the medial navicular on AP radiograph

• (B) Sclerosis and flattening of the navicular on AP radiograph

• (C) Sclerosis of the calcaneal epiphysis on lateral radiograph

• (D) Talar beak and C-sign on lateral radiograph

#15 Correct answer: B

The boy in the vignette has intermittent foot pain and localizes his pain to the medial aspect of the midfoot in the area of the navicular. The most likely finding on radiograph would be sclerosis and flattening of the navicular consistent with Kohler disease (navicular osteochondrosis). Kohler disease typically occurs in children between the ages of three and seven and affects males more than females. The exact etiology of Kohler disease is unknown but disruption of the blood supply to the navicular leads to fragmentation, flattening and sclerosis. Over time, the navicular regains its normal anatomy. Treatment involves symptomatic care. A brief period of immobilization (four to six weeks) may help mitigate symptoms. There are no known sequelae of Kohler disease. 

Sclerosis of the calcaneal epiphysis (Answer C) is a characteristic finding of Sever's disease (calcaneal apophysis); the boy in the vignette does not report heel pain and is younger than the typical patient with Sever's disease. A talar beak and C-sign can occur with tarsal coalition. Tarsal coalition typically presents with recurrent ankle sprains and pain in children from 8-13 years of age. A large ossicle (Answer A) is consistent with an accessory navicular and is a common cause of foot pain. Accessory naviculars typically become symptomatic during the pre- and early adolescent years and are palpable on physical examination.