More Case Vignettes Flashcards
A patient presents with difficulty walking. As you inspect their gait, you notice that the patient has difficulty bringing their leg forward in the swing phase of walking. The patient also has some difficulty flexing their trunk forwards when their legs are fixed in place (standing still or sitting). What muscle do you suspect is affected, and what is its innervation?
This is probably the iliopsoas muscle, which is the major hip flexor. It is innervated by ventral rami of L1-L3.
You are performing a lower extremity exam on your patient, a 53-year-old woman, when you notice that as she walks, the left side of her pelvis seems to sag lower than the right side. What muscles do you suspect are weakened in this patient, and what nerve innervated these muscles? What side is the problem located on?
This patient presents with the Trendelenberg sign, which tells you that there is weakness of hip abduction, causing the contralateral side of the pelvis to descend. The primary muscles involved in hip abduction are gluteus medius and gluteus minimus, innervated by the superior gluteal nerve. In this patient, the left side is sagging lower, so the right side is where there is weakness of hip abduction.
A 24-year-old medical student is complaining about leg pain following an intense workout (“leg day”). He says it’s been particularly hard to go up and down stairs, and that going down stairs hurts a lot, especially when he lowers himself down between each stair. What muscle is particularly sore, what is its primary action, and what innervated it?
This student has pain in the quadriceps femoris, the muscle primarily responsible for knee extension. It is innervated by the femoral nerve. It is important for going up and down stairs, especially because it provides the control to slowly lower you down on the stairs.
A 6-year-old girl presents to the ED with acute onset of severe hip pain. She has a history of an open fracture of the ulna sustained 2 weeks ago in a fall on the playground; the fracture was successfully reduced in surgery and she is now in a cast. In the ED, she appears agitated and upset, and has a fever. Her left hip is swollen and erythematous, and she has a limited active and passive range of motion on exam. What do you suspect is the diagnosis? What is the pathophysiology of this diagnosis? What will you do to confirm the diagnosis, and how will you treat it?
This patient is a pediatric patient with acute monoarthritis of the hip, concerning for septic arthritis. The history of trauma adds a risk factor supportive of this diagnosis.
Pathophysiology: Hematogenous spread of bacteria from her open fracture led to colonization of the joint space, causing inflammation and rapid cartilage destruction.
To confirm the diagnosis, perform a joint arthrocentesis to examine the synovial fluid, and send it for gram stain and culture, as well as cell count (WBCs will be elevated), and glucose (which is low in about half of cases). The fluid will look turbid and yellow with reduced viscosity.
Treat it with empiric ABX right after taking the aspirate, and source control (surgically since this is a hip, but aspirate could work for other joints).
Further management: blood culture to check for bacteremia, CBC, imaging as needed. IV ABX for two weeks, total time on ABX will be 4 weeks. Target S. Aureus with vancomycin, and expand coverage as needed to treat more unusual organisms if you suspect that would be a problem.
A 23-year-old woman presents to urgent care complaining of right knee pain. On history, she has had the pain for two days with swelling and redness in the knee and a limited range of motion. She denies any trauma or other injury to the knee. She denies any history of recent infection. She has no significant past medical history. She has not traveled overseas recently. She does not smoke or do any recreational drugs, drinks alcohol, and is sexually active, using the withdrawal method as her primary form of birth control. Plain films show some fluid in the knee joint, as well as joint space widening. What diagnosis do you suspect, and what will you take into account as you decide on a treatment plan?
This patient most likely has septic arthritis, and has many of the risk factors for gonococcal arthritis (young, female, sexually active). Gonococcal arthritis can present as a septic joint or as a reactive arthritis with multiple affected joints and a rash. The treatment for gonococcal septic arthritis is antibiotics started immediately after arthrocentesis, but the antibiotic regimen needs to also treat chlamydia, as the two infections tend to occur together.
You are treating a 50-year-old patient on your inpatient unit who has a medical history significant for current leukemia treatment. His treatment is going well, his blood counts have been good lately, and he has a PICC line in place for chemotherapy. He was admitted about 36 hours ago with a fever. Labs were drawn in the ED shortly before the time of admission, and when you come in to round in the morning, you see that blood cultures have come back showing bacteremia. He tells you when you see him this morning that he has had back pain for about two weeks in addition to his other medical problems. You examine his back and find a small open sore draining a small amount of yellowish fluid. What is the most likely cause of his back pain given his findings, how would you classify its etiology, and what risk factors does he have?
This patient probably has acute (2 wks) osteomyelitis, which is causing his back pain as well as the sinus tract draining fluid. The osteomyelitis is probably infecting his spine. His bacteremia suggests that this is of hematogenous etiology. The most likely portal of entry is his PICC line, as that’s his only indwelling device. If it was seeded with bacteria, that bacteria could get into the blood and cause a bacteremia that infected the spine via arteries feeding to the margins of his intervertebral discs, involving a vertebral disc and the vertebral bodies above and below it. He is at greater risk because he is immunosuppressed due to his treatment, and because he has the PICC line. He needs to be treated with antibiotics and source control, so the PICC line should probably be removed/replaced. He should also be evaluated for the possibility of endocarditis.
A 64-year-old woman comes into clinic today for a diabetes follow-up. She has been a type 1 diabetic since age 4. Her A1c today is 8.5%. On exam, you notice that she has an ulcer on the sole of her left foot that appears very deep. She tells you that she noticed the sore several months ago, and that “it left sticky stuff on my sock,” but she assumed it had healed because it was not hurting. When you insert a sterile metal probe into the lesion, you hear it clang as it hits something hard. What is the most likely diagnosis, and how will you treat it? What will you tell her about treatment goals?
This is chronic osteomyelitis due to continuous spread from an unhealed diabetic foot ulcer. Treatment will be multimodal - she needs surgical debridement to clean out the source of infection, and then ongoing ABX to treat any residual infection. You will want to counsel this patient that completely getting rid of the infection may not be possible, and a good goal is suppression of the infection in the long-term. Following debridement, she will be on antibiotics likely until the inflammation goes down or the wound heals. She also needs to take precautions against diabetic foot ulcers.
A 67-year-old man presents to clinic complaining of groin pain, difficulty climbing the stairs, and difficulty getting his leg into a position that allows him to tie his shoes. He has started using a cane due to the pain that he has had when walking. The pain does not radiate to any other part of his leg or back. On exam he has a decreased hip range of motion due to pain, and a negative straight leg raise test. What is the most likely diagnosis, and what do you expect to see on plain films?
This is most likely osteoarthritis of the hip due to the characteristic presentation. On plain films you would expect to see loss of joint space due to erosion of collagen, possibly with cysts, osteophytes, increased density, or sclerosis in that area.
On the differential: radiculopathy (frequently low back/buttock pain, radicular pain below knee, positive straight leg raise, neuro findings); vascular claudication (calf pain, specific pattern associated with exercise, abnormal pulses, loss of leg hair)
You’re watching a high-stakes World Cup soccer game when you see one of the players lunge for the ball. His back leg, which is planted firmly on the ground, is hyperextended and medially rotate at the knee. When he tries to sharply pivot to kick the ball, he falls to the ground, clearly in pain. What kind of injury is most likely, and what kinds of physical exam maneuvers can demonstrate the presence of this injury?
This is most likely an ACL tear. The ACL is weaker than the PCL and is most taut when the knee is fully extended. In extreme extension with the knee twisted medially and the foot planted, the ACL can tear. This can be assessed by the anterior drawer test of the knee (tibia moves forward more than 5 mm) or by the Lachman’s test, looking for instability in extension of the knee.
A patient presents to your sports medicine clinic complaining of a twisted ankle. The patient describes a sports injury where she forcefully inverted her ankle. What side of her foot is the injury on, and which ligament(s) did she most likely tear?
This is a typical inversion ankle injury, and she injured the lateral collateral ligament of the ankle. It is comprised of multiple parts that tend to tear from anterior to posterior. The anterior talofibular ligament is the most anterior, so that tends to tear first, followed by the calcaneofibular ligament and the posterior talofibular ligament.
You are performing a lower extremity MSK exam. While your patient is lying supine, you have her flex her knee and hip, flexing her hip as far forward as she can against resistance. What muscle is specifically tested with this movement, what innervates it, and why is it important?
This exam maneuver is testing flexion of the iliopsoas complex (iliacus and psoas major). The psoas major is innervated by ventral rami of L1-L3, and the iliacus is innervated by the femoral nerve (L2-4), and together iliopsoas is specifically important for flexing the trunk against gravity (doing sit-ups, etc).
A patient presents to your clinic after a traumatic injury that damaged the L2 and L3 ventral rami. Immediately after the injury, the patient could not flex his hip effectively, especially when bringing it all the way flexed with his knee flexed as well. However, over time and with physical therapy, the patient has developed an improved ability to flex the thigh at the hip. You notice on exam that the patient has increased muscle mass on the superior lateral portion of his thighs bilaterally. What muscles were injured, and what muscle hypertrophied to compensate?
This is describing an injury to iliopsoas due to nerve damage. The muscle that hypertrophied to compensate is the tensor fascia lata. This muscle is embedded in the IT band and is innervated by the superior gluteal nerve (L4-5). Its chief action is hip flexion, but it also controls AP tilting of the pelvis when standing on one leg (along with gluteus maximus), and stabilizes the knee in extension as well.
A 28-year-old woman presents to clinic due to new-onset leg pain while training for a marathon. The pain localizes to the lateral and proximal aspect of her thighs, and to her lateral knees. You believe she has a structure in her leg that has become inflamed where it crosses a bony structure. What structures are involved, and what condition is this?
This is inflammation of the IT band, where the IT band crosses the lateral femoral condyle. It commonly can become inflamed in runners.
A soccer player feels pain in her leg during practice after doing a drill that requires her to forcefully kick the ball towards the goal multiple times. You ask her to flex her leg at the knee, and then extend her leg against resistance. This maneuver elicits pain. What muscles are most likely sore? If she also had pain with flexing the hip joint, what muscle would most likely be involved?
This patient has pain in her quadriceps muscles - rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis. These four muscles are innervated by the femoral nerve (L2-4) and are the major extensors of the knee. However, rectus femoris is also a hip flexor, so if there were also pain with hip flexion, that would suggest that rectus femoris was involved specifically.
A football player is injured during a game and complains of groin pain. On exam you notice that he has difficulty adducting his left leg against resistance. What group of muscles is most likely torn at its proximal attachment, what action does it perform, and how are these muscles innervated?
This patient has most likely torn his adductor muscles of the thigh (adductor longus (most anterior), adductor brevis, and adductor magnus). These muscles primarily addict the thigh. Adductor longus and brevis can also flex and medially rotate the thigh. The upper portion of adductor magnus can flex and medially rotate the thigh. The lower portion of adductor magnus helps to extend and late really rotate the thigh. The adductors are innervated by the obturator nerve (L2-4).
