Pain and Interventional

Question 1

During an ultrasound-guided injection, you notice that the needle appears as a bright white dot on the screen. Which of the following injection approaches is the physician using?

Answer 1

Out-of-plane
- Short and long axis terminology describes the view of the target structure, not the approach of the needle. In short axis, a structure is viewed in “cross section”. In long axis, the structure is viewed along its entire length, and a cross-sectional view is not obtained. In-plane needle injection technique involves the needle length being parallel to the ultrasound transducer, and thus, the entire needle can be visualized underneath the skin. Out of plane technique involves the needle being advanced perpendicular to the ultrasound transducer, and, thus, only a small (dot-sized) portion of the needle is viewed at any given moment on the screen. In an out-of-plane approach, the needle is viewed in short axis, whereas in the in-plane approach, the needle is viewed in long axis.

Question 2

A 43 year old male with a history of ankle fracture describes increased sensation in his ankle ever since the injury. This phenomenon is known as which of the following?

Answer 2

Hyperesthesia is simply “increased sensation”. Hyperalgesia is increased pain in response to a stimulus that normally is painful. Allodynia is pain in response to light touch on the skin. Dysesthesia is an abnormal, unpleasant sensation.

Question 3

A 29 year-old female presents with several months of widespread body pain. She has tried physical therapy to no benefit. She feels fatigued on most days. She is tender to palpation at multiple different locations throughout her body. You decide to recommend water aerobics and which other appropriate intervention?

Answer 3

Duloxetine
- Fibromyalgia presents classically as this patient does. Generally no medical or imaging workup is required. There is often comorbid fatigue, anxiety, and depression, as well as lifestyle stressors. Aquatherapy/water aerobics is an excellent first-line treatment. SNRIs, SSRIs, TCAs, and gabapentin or pregabalin are also appropriate as medication trials. Generally a primary care physician or psychiatrist should handle an SSRI prescription. Opioids are not indicated in fibromyalgia. Duloxetine is an excellent initial pharmacologic therapy as a pain + mood medication. “Standard” MSK-pain treatment modalities may not be effective in fibromyalgia, which carries a strong psychiatric component, hence duloxetine’s appropriateness over TENS or NSAIDs.

Question 4

A 56 year-old male complains of 2 months of low back pain radiating into the right lower extremity. MRI of the lumbar spine reveals an L3-L4 paracentral disc herniation. Which of the following nerves is most likely being compromised?

Answer 4

In the lumbar spine a central or paracentral disc herniation will involve the descending nerve root at that level (e.g. at the L3-L4 level, the L3 nerve is exiting via the neuroforamen, and the L4 nerve is descending to exit via the neuroforamen at the L4-L5 level).

Question 5

A 23 year-old male presents with gradual onset 1 year of right knee pain. He is a division 1 basketball player and the national postseason tournament is about to begin. He is adamant that he must play, as his team is expected to win the championship. He has tried ibuprofen, tried 2 rounds of physical therapy and home exercises, as well as relative rest, all of which has not helped his pain. He has tenderness to palpation of his patellar tendon, and there is pain at the patellar tendon with resisted knee extension. His right patellar tendon appears swollen compared to his left. He has had unremarkable knee x-rays, and a knee MRI showed intact soft tissue structures. On diagnostic ultrasound scan, you note a thickened, hypoechoic, wavy appearance of the right patellar tendon compared to the fibrillar, relatively hyperechoic appearance of the left patellar tendon. Color doppler scan reveals punctate red and blue dots within the right patellar tendon, but not the left. What is the most appropriate next step?

Answer 5

Ultrasound-guided patellar tendon scraping
- This patient presents with classic findings of patellar tendonitis that has progressed into patellar tendonosis. Recall that tendonosis is a degenerative condition of a tendon that occurs due to tendon overuse. The tendon becomes wavy, thickened, and hypoechoic (dark) on ultrasound. Neurogenic inflammation accompanies this, in which neovessels and neonerves sprout from the Hoffa (infrapatellar) fat pad and extend into the patellar tendon, which causes chronic knee pain. Tendon scraping under ultrasound guidance involves guiding a needle between the patellar tendon and Hoffa fat pad (not into the tendon itself, despite the name “tendon scraping”) and moving the needle back and forth (superior to inferior and vice versa) in order to sever these neonerves and neovessels, thus treating the patient’s source of pain (the neonerves), and breaking the cycle of tendonosis, allowing the patient to progress in PT without the pain limitation from the neonerves. Orthopedic surgery is a last resort. Also, the patient may weight-bear immediately and perform physical activities after a tendon scraping, because the tendon itself was not pierced by a needle or scalpel, and so is still structurally intact.

Question 6

Which of the following is the most appropriate choice of needle for a routine palpation-guided intra-articular knee injection?

Answer 6

25 gauge 1.5-inch needle

Question 7

A 27 year-old female sustains a severe wrist fracture during a fall while rock climbing. She undergoes orthopedic surgery for treatment. She presents to your clinic 4 months later with complaints of severe wrist pain. She has also noticed swelling of the wrist, sweating, and severe pain when washing her hands. She was evaluated by her primary care physician who ruled out cellulitis and then referred her to you. X-rays demonstrate osteopenia in the wrist. Which of the following is the next best diagnostic step?

Answer 7

Stellate ganglion block
- Complex regional pain syndrome (CRPS) comes in two types. Type 1 is sympathetically mediated pain due to an unknown etiology (usually occurs after trauma) that results in an area of the body experiencing increased neuropathic pain, hypersensitivity, allodynia, skin vasomotor changes, and edema. X-rays will show periarticular osteopenia. Type 2 is these symptoms in the context of a known, documented peripheral nerve injury; Type 2 is also called causalgia. Treatment is aggressive daily ROM and use of the affected body part, oral corticosteroids, NSAIDs, anticonvulsants, beta blockers, topical medications, desensitization therapy, and TENS. Stellate ganglion block is the best diagnostic test, and can also be therapeutic.

Question 8

The Gate Control Theory of pain modulation functions due to which of the following anatomical principles?

Answer 8

Light touch impulses synapse onto the same neurons in the spinal cord as do pain impulses

Question 9

A 78-year-old female is undergoing a balloon kyphoplasty procedure to treat a painful T7 vertebral compression fracture. Near the end of the procedure, she suddenly experiences severe chest pain and shortness of breath. What is the most likely explanation?

Answer 9

Cement embolization
- Cement should be visualized under fluoroscopy while filling a vertebral compression fracture. In rare instances, if the polymethylmethacrylate (PMMA) cement does not remain contained within the vertebral body, it can enter the venous system and embolize to the lungs.

Question 10

A 45 year old female complains of severe pain when you apply light touch to the skin of her hand. What is the name of this phenomenon?

Answer 10

The only definition that cleanly and best fits this question is allodynia: pain elicited from a normally nonpainful stimulus. Hyperalgesia is increased pain from a normally painful stimulus. Dysesthesias are abnormal, unpleasant sensations. Hyperpathia vs. hyperalgesia is too nuanced for you to be tested on it on Part I boards.

Question 11

Which of the following neural structures transmits light touch and pressure impulses?

Answer 11

A-beta fibers
- Light touch is transmitted by A-beta (large, myelinated) fibers. C fibers are the other main one to know (they are small, unmyelinated, and transmit pain impulses).

Question 12

The area of hypovascularity of the achilles tendon (leading to tears in this region) is generally at which of the following locations on the tendon?

Answer 12

The achilles tendon’s zone of hypovascularity is generally within the distal 2-6 cm of the tendon, predisposing this region to tendon tears due to the poor blood supply.

Question 13

You are evaluating a patient for posterior heel pain. A lower extremity MRI reveals a complete tear of the achilles tendon. However, when you perform the Thompson test, it is negative. How is this possible?

Answer 13

In a patient with complete achilles tendon rupture, the Thompson test should be positive. Recall that a positive Thompson test is detected by squeezing the patient’s calf and documenting a lack of plantarflexion, indicating a complete achilles tendon tear. If a patient has a confirmed achilles tendon rupture on MRI, yet demonstrates a falsely negative Thompson test, this seems like it would be impossible, but in reality the examiner is likely squeezing enough to cause contraction of the plantaris tendon, which also attaches to the calcaneus, and can perform plantarflexion. In summary, squeezing the calf does not only squeeze the gastrocnemius and soleus, but also the plantaris muscle and tendon, which sit between the gastrocnemius and soleus, and all of these muscles may provide plantarflexion function to the ankle. An MRI-confirmed achilles tendon rupture is not likely to be incorrect. Naturally occurring bifid achilles tendons are fictional. This Thompson test is a false negative result, not a false positive.

Question 14

A 62 year-old male complains of 5 months of low back pain radiating into the left lower extremity. MRI of the lumbar spine reveals an L4-L5 far lateral disc herniation. Which of the following nerves is most likely being compromised?

Answer 14

L4
- In the lumbar spine a central or paracentral disc herniation will involve the descending nerve root at that level (e.g. at the L3-L4 level, the L3 nerve is exiting via the neuroforamen, and the L4 nerve is descending to exit via the neuroforamen at the L4-L5 level; thus, a central or paracentral disc herniation at the L3-L4 level will potentially impinge the descending L4 nerve roots). A far lateral disc herniation will affect the exiting nerve root at a given spinal level (in the case of our patient in the question above, this is the L4 nerve root).

Question 15

During an interlaminar epidural steroid injection, you advance the needle tip between the L4 and L5 laminae, when suddenly the syringe plunger auto-depresses all the way down, evacuating the syringe of its contents. Which of the following is the most appropriate next step?

Answer 15

Inject contrast dye
- During an interlaminar epidural steroid injection (ESI) the goal is to pierce the ligamentum flavum and enter the epidural space. During an interlaminar ESI, a “loss of resistance syringe” is used to confirm entry into the epidural space. Upon entering the epidural space, this syringe will automatically depress its contents due to a sudden loss of resistance in its environment. In other words, the syringe plunger is not able to auto-inject its contents in the muscle and fascia it travels through on its way through the patient’s back, into the epidural space, due to the resistance of these firm tissues to injection. However, upon entering the epidural space, suddenly all this resistance is gone, allowing the syringe to easily auto-inject its contents into the epidural space. Thus, when performing an interlaminar epidural steroid injection, the way to confirm successful presence of the needle tip within the epidural space is to advance the needle tip until the syringe plunger depresses all the way down by itself freely. Further anteroposterior and lateral view imaging may be obtained to confirm three-dimensional position before injecting contrast dye to view epidural flow of medication. Following agreeable flow of contrast dye (into the epidural space, termed an epidurogram), a syringe containing the epidural steroid medication is attached to the needle for injection into the exact same space as the contrast dye.

Question 16

Peripheral nerve stimulation (PNS) may improve a patient’s pain by which of the following mechanisms?

Answer 16

PNS operates chiefly on the principle of neuromodulation: by electrically stimulating a given nerve involved in the transmission pathway of a patient’s pain, the nerve and corresponding body region may be “reprogrammed” to transmit less pain and ultimately lead to reduced conscious subjective experience of pain by the patient.

Question 17

Which of the following steroids is safest to use in a transforaminal epidural steroid injection?

Answer 17

Dexamethasone
- Triamcinolone, methylprednisolone, and betamethasone are particulate steroids. Dexamethasone is a non-particulate steroid. Many case reports have detailed spinal cord infarctions following injection with particulate steroid in transforaminal epidural steroid injections. While rare, this catastrophic outcome can occur if particulate steroid is inadvertently injected into the artery of Adamkiewicz or radiculomedullary arteries.

Question 18

You are preparing to inject a patient’s exposed shoulder with lidocaine and triamcinolone in an effort to treat rotator cuff pain. You prepare your supply tray, and ensure that gauze and an adhesive bandage are present. You draw up 2 milliliters of 1% lidocaine and 1 milliliter of 40 mg/ml triamcinolone into a syringe. As you are about to begin the procedure, you pause. Which of the following steps will most likely prevent iatrogenic infection?

Answer 18

A key feature of every procedure is using a skin sterilization method, such as alcohol or chlorhexidine application to a pre-marked area of skin and allowing it to dry prior to needle entry. Skin sterilization with one of the above agents is the only option of those listed above that will prevent infection from needle insertion, and is required in every procedure. Using a different local anesthetic agent is usually a matter of personal preference and availability of medications. Pre-procedural time-out to determine correct patient, procedure, site of action, and staff and patient agreement with stated procedure is necessary prior to every procedure, but without skin sterilization, will not prevent infections. Counseling your patient on what to expect during and after a procedure is necessary, but will not directly act to prevent an infection in the first place.

Question 19

You are performing a palpation-guided trigger finger injection. You advance the needle into the target location and ask the patient to flex the involved finger. With finger flexion, the syringe moves. Which of the following is the most appropriate next step?

Answer 19

Withdraw the needle tip slightly, then repeat finger flexion
- A palpation-guided trigger finger injection requires that the needle tip be advanced just into the tendon sheath, but not into the tendon itself. Thus, if the needle tip lies within the tendon itself, upon finger flexion the syringe and needle will move along with the tendon. The key here is to withdraw the needle tip slightly, so that the needle tip remains within the tendon sheath, but not within the tendon. If the needle tip lies in the tendon sheath alone, then upon finger flexion, the syringe will not move, indicating that the needle tip is in the correct location, and the injection may proceed.

Question 20

A 52 year-old male presents with 3 weeks of anterior right knee pain and swelling. On examination you detect a bulbous, soft, fluid-filled pouch just anterior to the patient’s patella, which is tender to palpation. The patient denies fever, chills, rash, or tick exposure. He works in home construction and spends a lot of his time on his hands and knees installing flooring. Strength, sensation, and reflexes are intact in both lower extremities. He asks you to do something today for him, because his pain is unbearable. Which of the following is the most appropriate next step?

Answer 20

Aspiration alone
- This patient presents with classic prepatellar bursitis, the fluid-filled distension of the prepatellar bursa just anterior to the knee cap (patella). This is most often irritated with prolonged anterior knee friction/compressive forces (e.g. prolonged kneeling). Prepatellar bursitis can be painful. Knee pads are a useful conservative treatment for this problem in patients who are willing to trial conservative care alone. This patient requests urgent treatment today; thus, aspiration of the prepatellar bursa is warranted. Corticosteroid injection is not appropriate into this superficial bursa, as this will increase the risk of infection without added clinical benefit. Orthopedic surgery referral for bursectomy is not indicated except in intractable cases.

Question 21

You are rounding on a patient in a skilled nursing facility. This 52 year-old male with T8 ASIA A spinal cord injury, utilizing a new manual wheelchair for mobility, complained of right shoulder pain during physical therapy sessions. You diagnosed right glenohumeral joint osteoarthritis and performed a right glenohumeral joint triamcinolone injection 5 days ago. Today he notes 2 days of increasing warmth, redness, swelling, and pain in the right shoulder, worse than before the procedure. His temperature is 101.4 degrees Fahrenheit. Which of the following is the most appropriate next step in management?

Answer 21

Initiate oral cephalexin
- This patient presents with post-procedure septic arthritis, likely due to procedure contamination with skin flora. This is a known risk of procedures, especially when non-sterile or unclean procedural practices are undergone. The patient typically develops in the days following the procedure worsening joint pain along with redness, swelling, +/- fever. Empiric oral antibiotics are an appropriate starting point while joint x-ray and synovial fluid aspiration and gram stain with culture and cell count with differential are undergone. Initiation of early antibiotic treatment is critical to prevent further joint destruction and risk of infection spread and death. Of the answer choices, the only selection which works to immediately treat this serious problem is antibiotic therapy.

Question 22

Neuronal C-fibers transmit which type of impulse?

Answer 22

Pain
- C fibers transmit pain signals and are slow, small, and unmyelinated.

Question 23

You are seeing a 26 year-old marathon runner in follow-up. You previously prescribed physical therapy for achilles tendon pain. Since finishing the physical therapy, the patient notes minimal relief of their pain. You decide to perform a diagnostic ultrasound scan of the achilles tendon. Immediately you notice a thickened, hypoechoic appearance of the tendon. Color doppler reveals punctate pulsations of blood flow within the tendon. What is the etiology of this condition, defined by the totality of these ultrasound findings?

Answer 23

Chronic degeneration
- The findings above describe findings of tendonosis, which is a chronic degenerative process. This is typically due to poor strength and overuse of the tendon. Subsequent neurogenic inflammation can develop, as indicated by the color doppler flow. Physical therapy is a good starting treatment for this. Failing this, it is reasonable to try regenerative tendon interventions with ultrasound guidance.

Question 24

A 45-year-old male presents to your clinic for evaluation of chronic axial low back pain. He underwent medial branch blocks without any significant relief. His lumbar spine MRI reveals no significant canal or foraminal stenosis but does show endplate degenerative changes (Modic Type I) at the L5-S1 endplates. You suspect these changes as the cause of his pain. What nerve is responsible for the sensory innervation from the vertebral endplates?

Answer 24

Basivertebral nerve
- The basivertebral nerve is a paired nerve that originates from the sinuvertebral nerve and enters the vertebral body through the basivertebral foramen, carrying signals from the superior and inferior endplates of its respective vertebral body. This nerve is clinically relevant, as it can be targeted for ablation in cases of pain suspected to be arising from degenerative endplate changes.

Question 25

A 36 year-old female presents with persistent neck pain for the past several months. X-rays and MRI of the neck are normal. She has performed physical therapy, home exercise program, and postural re-education to no benefit. Acetaminophen, ibuprofen, and cyclobenzaprine have not helped. On exam, strength and sensation are intact. When palpating the posterior neck muscles and upper trapezius bilaterally, you feel a taut band of tissue, and after “plucking” it, you observe it twitch several times. Which of the following is the most appropriate next step?

Answer 25

Lidocaine injection
- This patient presents with classic myofascial pain due to trigger points, as described in the exam. Trigger points are most appropriate treated with physical therapy, postural mechanics, and oral medications as noted. When these conservative measures fail, trigger point injections are appropriate. Some physicians perform a dry needle injection, but most perform either lidocaine or lidocaine + corticosteroid. The purpose of the trigger point injection is to provide myofascial pain relief by numbing the painful area and “breaking up” the tight tissue via needle entry and localized bleeding introduced by the needle tip. Relief from trigger point injections, if obtained, is typically between 1 hour and 1 month, and varies among patients.

Question 26

A 41 year-old male presents with 9 months of gradual onset low back pain. He denies trauma. He has tried physical therapy and ibuprofen but has only received minimal improvement. On exam while supine, hanging one leg off the side edge of the exam table reproduces his low back pain. Which of the following is the most reasonable next step?

Answer 26

Sacroiliac joint injection
- This patient with low back pain secondary to sacroiliac joint dysfunction (positive Gaenslen test) and failing conservative treatments should consider a sacroiliac joint injection as the next step in care. A spinal cord stimulator trial is used in very refractory, chronic cases.

Question 27

A hyperirritable band of tight muscle and fascia that produces local numbness and tingling along with radiating pain is also known by which of the following names?

Answer 27

Trigger point
- A trigger point is defined as in the question stem. A trigger point can be palpated and appreciated by the physician. A tender point is something that cannot be truly felt by the physician, and does not typically radiate pain outward. Myofascial pain and myalgias are subjective feelings of pain arising from muscle + fascia, and muscle, respectively.

Question 28

During a routine knee injection, just before injecting the medication, you maintain the current position of your needle while you briefly pull back on the plunger of the syringe. Which of the following is the primary purpose of this practice?

Answer 28

To confirm that the needle tip is not located within a blood vessel
- The reason that we attempt aspiration (pulling back on syringe plunger briefly) just before injecting medication is to confirm that the needle tip is not located within a blood vessel. Injecting medication intravascularly can cause serious undue medical complications to the patient, and is absolutely contraindicated when attempting to perform routine musculoskeletal procedures. If there is a “flashback” of blood/heme in the syringe when aspiration is attempted, the needle position must be adjusted to a new location, and there must be heme-negative aspiration before medications can be injected.

Question 29

The notion of light touch and pressure sensations inhibiting pain signals is known by what name?

Answer 29

The Gate Control Theory
- This question describes the Gate Control Theory by which light touch/vibration/pressure impulses on the skin can synapse onto wide dynamic range neurons in the spinal cord and inhibit C-fiber (pain) signals which also synapse onto these neurons, thus inhibiting pain transmission to the brain.

Question 30

The final ligament pierced by a spinal needle during an epidural injection is which of the following?

Answer 30

Ligamentum flavum
- The ligamentum flavum is the final ligament that is pierced by an epidural needle during an epidural injection. Once piercing the ligamentum flavum, classically a “loss of resistance” is felt in the syringe, meaning that it is now much easier to inject medication through the syringe, now that the needle has entered the relatively “wide open” epidural space.

Question 31

If you wanted to target a patient’s back pain by blocking the nerves that innervate the right L4-L5 facet joint, which nerves would you block?

Answer 31

L3 and L4 medial branches
- In the lumbar spine, a given facet joint is innervated by the higher level of the two, and the level above. For example, the L4-L5 facet joint is innervated by the L3 and L4 medial branches.

Question 32

A 68 year-old male presents with gradual onset low back pain for the past 2 years. He found a recent physical therapy course to be too painful to endure. Acetaminophen provides minor pain relief. He denies trauma, numbness, tingling, or weakness. On exam he has intact strength and sensation. Rotating his torso to the left while extending his spine reproduces his pain, as does the same maneuver towards the right. Gaenslen test is negative. What is the next best step?

Answer 32

MRI lumbar spine
- This patient suffers from lumbar facet arthropathy, as evidenced by his positive physical exam maneuver which challenges the lumbar facet joints. Initial therapy is oral medications (acetaminophen, NSAIDs) and physical therapy. Failing this, MRI of the lumbar spine and facet joint interventions should be considered. The purpose of the MRI is to ensure that it is safe to move forward with spine injections/interventional procedures such as medial branch blocks. Occasionally the MRI will show a more serious surgical issue for which an x-ray-guided spinal procedure would not have been appropriate or safe to perform.

Question 33

A spinal cord stimulator functions by which of the following principles?

Answer 33

Gate Control Theory
- TENS units and spinal cord stimulators function via the Gate Control Theory, by which electrical impulses upon light touch/vibration pathways can inhibit pain signals traveling up the spinal cord.

Question 34

A 24 year-old previously healthy male presents with low back pain and stiffness for the past 1 year. He denies leg symptoms. On exam, forward lumbar flexion is extremely limited due to stiffness. Which of the following imaging studies will be most helpful?

Answer 34

Pelvis x-rays
- This patient’s symptoms and exam are suspicious for Ankylosing Spondylitis (AS). AS typically presents with low back pain and stiffness in a young male. Ankylosis (fusion) can occur along the entire spine, leading to back stiffness. The Schober test demonstrates limited lumbar flexion. It is performed by having the physician mark a spot on the skin roughly at the L5 level, then mark a spot 10cm superior to this spot and 5cm inferior to it. With forward lumbar flexion these spots should separate, and the distance between them (normally 15cm) should increase to greater than 20cm. In AS patients this lumbar flexion will be so limited that the distance may only increase by under 5cm, indicating a positive test in support of the AS diagnosis. Patients with suspected AS should have pelvis x-rays to demonstrate the key pathognomonic feature of this disease, which is bilateral sacroiliitis.

Question 35

Pain signals are introduced to peripheral tissue, then transmitted into the spinal cord and brain where they are ________, leading to final perception of pain.

Answer 35

Modulated
- Pain signals are modulated as they are transmitted from the periphery to the higher cortical centers where perception occurs.

Question 36

A 29 year-old female presents to your clinic with complaints of 1 month of left wrist pain. Her pain is intermittent and mild. She gave birth to her new baby daughter 6 weeks ago. She denies numbness or tingling. On exam, strength is intact. When tucking the thumb into the palm and making a fist, then ulnarly deviating the wrist, the patient experiences sudden-onset exquisite pain that reproduces her usual wrist pain. What is the most appropriate next step?

Answer 36

NSAIDs, thumb spica splint
- This patient with a positive Finkelstein test as noted in the question stem, has findings highly suspicious for 1st extensor compartment tenosynovitis, or De Quervain Tenosynovitis (inflammation of the abductor pollicis longus and/or extensor pollicis brevis tendon sheath). This commonly occurs in new mothers who are spending a lot of time straining their wrists, holding their new baby. If conservative measures have failed, such as oral over the counter medications, and/or the pain is constant and severe, then ultrasound-guided corticosteroid injection into the tendon sheath (not the tendon itself!) is indicated, and is highly effective for this disease. However, in this patient, her pain is only mild, and she is not yet attempted conservative measures such as NSAIDs or thumb spica splinting; these should be tried first.

Question 37

A 64 year-old male with a history of hypertension presents to your clinic with the chief complaint of right shoulder pain. He describes right shoulder pain radiating to the elbow but not beyond, worse with reaching overhead, lifting with his right arm, and lying on his right side. He denies neck pain, numbness, or tingling, but feels right shoulder weakness due to pain. X-ray of the right shoulder shows severe glenohumeral arthritis. MRI of the right shoulder reveals complete tears of supraspinatus and infraspinatus tendons with retraction. He was evaluated by orthopedic surgery and deemed not a surgical candidate; patient is also not interested in surgery. He has tried oral acetaminophen, ibuprofen, and cyclobenzaprine for this pain for years. He tried oxycodone but had to stop due to side effects. A right shoulder subacromial bursa corticosteroid injection provided 2 weeks of good pain relief while a right shoulder glenohumeral joint corticosteroid injection provided 1 week of good pain relief. Physical therapy worsened his pain, so he stopped. The shoulder pain severely limits his quality of life and function. Which of the following is the next best step?

Answer 37

Suprascapular nerve peripheral nerve stimulation (PNS)
- PNS is likely a good option to consider for this patient, assuming no contraindications. Rotator cuff and glenohumeral joint neuromodulation can be achieved via stimulation of the suprascapular nerve. There is no clear evidence of cervical radiculopathy in this patient, thus cervical epidural steroid injection is not warranted. All reasonable options should be exhausted before considering chronic opioid therapy; the patient also experienced side effects with previous opioid, so this is not likely a good option for him. A repeat right shoulder x-ray is not likely to change management in this patient with no new trauma since the previous x-ray.

Question 38

During a diagnostic ultrasound scan, you notice a structure that appears anechoic. Which of the following are you most likely viewing?

Answer 38

Cyst
- On ultrasound, hyperechoic means bright white, hypoechoic means darker, and anechoic means black. If a structure is hyperechoic, it is bright because essentially all the sound waves hitting that structure are bouncing off it, right back to the transducer, where the computer interprets this intense signal by brightening it on the screen. Bone, thus, is hyperechoic, as no sound waves are penetrating through the cortex. Tendons and nerves can be hyper- or hypoechoic depending on how the transducer is angled upon them. Fluid, however, such as blood vessel lumens, cysts, bursae, is typically very hypoechoic or anechoic, as the sound waves travel right through the fluid instead of bouncing back at the transducer. Thus, the computer is not receiving any sound waves bouncing back from the fluid, and colors that region of the screen dark as a result.

Question 39

You have evaluated a patient for axial low back pain with a L4-S1 spinal fusion with pedicle screws (that have effectively destroyed their accompanying medial branches) and determined that the L3-4 facet joint is the primary source of the patient’s pain. You elect to pursue diagnostic medial branch blocks. Which medial branch(es) should you block?

Answer 39

L2
- The L3-4 facet joint is innervated by the L2 and L3 medial branches. In the setting of pedicle screws at L4, the L3 medial branch will have been effectively destroyed in most cases. Thus, in this case it would only be necessary to target the L2 medial branch to effectively anesthetize the L3-4 facet joint.

Question 40

A 29 year-old male presents in follow up for left tennis elbow. He has tried RICE, PT, acetaminophen/NSAIDs, and corticosteroid injection to only minimal benefit. It is summer time, and he is disappointed because he is looking forward to playing in an upcoming tournament in London. He wonders if there is anything else he can do. Which of the following is the most appropriate recommendation?

Answer 40

Needle tenotomy of common extensor tendon
- This patient has failed conservative treatments as well as one corticosteroid injection which provided no benefit. At this point regenerative interventions may be considered, including needle tenotomy, platelet-rich plasma, prolotherapy, etc. Surgery would be a last resort.

Question 41

A 23 year-old female sustains a severe lateral ankle sprain with a tibial-fibular fracture. She undergoes orthopedic surgery for treatment. She presents to your clinic 4 months later with complaints of severe ankle pain. She has also noticed swelling of the ankle, sweating, and severe pain when she dons and doffs a sock. She was evaluated by her primary care physician who ruled out cellulitis and then referred her to you. What is the most likely diagnosis?

Answer 41

Complex regional pain syndrome
- Complex regional pain syndrome (CRPS) comes in two types. Type 1 is sympathetically mediated pain due to an unknown etiology (usually occurs after trauma) that results in an area of the body experiencing increased neuropathic pain, hypersensitivity, allodynia, skin vasomotor changes, and edema. X-rays will show periarticular osteopenia. Type 2 is these symptoms in the context of a known, documented peripheral nerve injury; Type 2 is also called causalgia. Treatment is aggressive daily ROM and use of the affected body part, oral corticosteroids, NSAIDs, anticonvulsants, beta blockers, topical medications, desensitization therapy, and TENS. Stellate ganglion block is the best diagnostic test, and can also be therapeutic.

Question 42

A 47 year-old male presents with 3 weeks of nonpainful left elbow swelling. He denies numbness, tingling, weakness, fever, chills, or trauma. He is an architect and draws blueprints for buildings as part of his work. He is bothered by the cosmetic appearance of the swelling. On exam, you note a posterior elbow fluctuant mass which is nontender to palpation; there is no rash. Neurologic examination is normal in the upper extremities. You trial an elbow pad; he returns 1 month later stating that the swelling is unchanged. Which of the following is the next best step in management?

Answer 42

Aspiration alone
- This patient presents with classic olecranon bursitis. This is a commonly nonpainful outpouching of fluid due to irritation/bursitis of the olecranon bursa in the posterior elbow, which lies just deep to the skin over the olecranon. Olecranon bursitis is more likely in individuals who lean on their elbows or otherwise experience frequent friction/compressive forces to their posterior elbow. Treatment involves elbow padding as conservative care; if this fails, olecranon bursa aspiration is likely indicated. Corticosteroid injection is not warranted in the bursa, as injection of this superficial bursa with corticosteroid will increase the risk of infection without added clinical benefit compared to aspiration alone. Orthopedic surgery referral is indicated in recalcitrant cases failing aspiration. There is little to no clinical suspicion of an infected bursa in this patient, thus empiric antibiotics alone are not warranted.

Question 43

You are planning to perform a medial branch block on a patient for the treatment of lumbar facet pain. When planning your procedural approach, you aim to place your needle tip at the course of the medial branch of the primary dorsal ramus, which lies between which two structures?

Answer 43

Superior articular process and transverse process
- The course of the medial branch runs between the superior articular process and transverse process down the pedicle (or the “eye of the Scotty dog”) as it courses toward the facet joint.

Question 44

A 55-year-old male presents with chronic mid-back pain. After physical examination and imaging, you suspect facet arthropathy affecting the T8-9 facet joints as the source of his pain. You elect to perform a diagnostic medial branch block. Which medial branches should be targeted for this procedure?

Answer 44

T7 and T8
- The T8-9 facet joint receives its innervation from the T7 and T8 medial branches of the dorsal ramus, and these should be targeted for diagnostic medial branch blocks.

Question 45

A 30 year-old female presents to your clinic with complaints of 1 month of right wrist pain. Her pain is constant, severe, and only mildly relieved with ibuprofen. She gave birth to her new baby daughter 6 weeks ago. She denies numbness or tingling. On exam, strength is intact. When tucking the thumb into the palm and making a fist, then ulnarly deviating the wrist, the patient experiences sudden-onset exquisite pain that reproduces her usual wrist pain. What is the most appropriate next step?

Answer 45

Ultrasound-guided injection
- This patient with a positive Finkelstein test as noted in the question stem, has findings highly suspicious for 1st extensor compartment tenosynovitis, or De Quervain Tenosynovitis (inflammation of the abductor pollicis longus and/or extensor pollicis brevis tendon sheath). This commonly occurs in new mothers who are spending a lot of time straining their wrists, holding their new baby. If conservative measures have failed, such as oral over the counter medications, and/or the pain is constant and severe, then ultrasound-guided corticosteroid injection into the tendon sheath (not the tendon itself!) is indicated, and is highly effective for this disease.

Question 46

A 34-year-old female presents to your clinic following a fall onto her tailbone while roller-skating. Despite a 2-week course of rest, NSAIDs, and donut cushions, her pain remains severe at 8/10 and constant. Imaging is negative for fracture or displacement of the coccyx. Which of the following treatments is most appropriate at this time?

Answer 46

Physical therapy
- Physical therapy (including pelvic floor physical therapy) has excellent evidence in the treatment of coccydynia and should be trialed prior to consideration of interventional procedures or other more aggressive treatment options. 90% of cases of coccydynia will resolve with conservative measures, including rest, NSAIDs, offloading, and physical therapy. Interventional procedures can be considered in cases refractory to conservative treatment.

Question 47

During a diagnostic ultrasound scan, you notice a structure that appears like a honeycomb. Which of the following are you most likely viewing?

Answer 47

Nerve
- On ultrasound, in a short axis view (cross-sectional view), a nerve looks like a honeycomb. Veins and arteries look like hollow (dark/anechoic) tubes that are compressible by the transducer. A tendon appears more uniformly hyperechoic (bright) than a nerve.

Question 48

A 51 year-old female presents to your clinic complaining of chronic migraines. Her headaches started several years ago and typically involve pain at the base of her skull which radiates over the top of her left ear in bursts several times daily. She denies inciting event, trauma, numbness, tingling, or weakness. MRI of the cervical spine shows mild degenerative changes at C5-C6 with mild bilateral foraminal stenosis. She has tried physical therapy, acetaminophen, naproxen, amitriptyline, topiramate, and gabapentin for this pain without sufficient pain relief. Which of the following is the next most appropriate step in management?

Answer 48

Occipital nerve block

Question 49

A 24 year-old male sustains a Maisonneuve fracture. This is complicated by neurologic weakness in the fibularis longus and brevis muscles, and impaired sensation over the lateral lower leg and dorsum of the foot. Over the next few months he develops abnormal sweating in the lower leg, as well as excruciating pain when putting on a sock. What is the most likely diagnosis?

Answer 49

Complex regional pain syndrome type 2
- Complex regional pain syndrome (CRPS) comes in two types. Type 1 is sympathetically mediated pain due to an unknown etiology (usually occurs after trauma) that results in an area of the body experiencing increased neuropathic pain, hypersensitivity, allodynia, skin vasomotor changes, and edema. X-rays will show periarticular osteopenia. Type 2 is these symptoms in the context of a known, documented peripheral nerve injury; Type 2 is also called causalgia. Treatment is aggressive daily ROM and use of the affected body part, oral corticosteroids, NSAIDs, anticonvulsants, beta blockers, topical medications, desensitization therapy, and TENS. Stellate ganglion block is the best diagnostic test, and can also be therapeutic.

Question 50

A positive geyser sign at the acromioclavicular (AC) joint most likely indicates which of the following pathologies?

Answer 50

Osteoarthritis
- The geyser sign refers to the concept of viewing the AC joint on ultrasound and detecting a large amount of fluid within the joint which pushes upward against the AC ligament, pushing it upward and outward, much like a geyser of fluid. Of the choices listed, osteoarthritis in the AC joint is most likely to cause this.