hand and lower extremity Flashcards
A 19-year-old woman is evaluated 2 hours after jamming her finger while playing basketball. She has pain with resisted extension and a 20-degree extensor lag at the proximal interphalangeal (PIP) joint, but she is able to actively flex and extend the joint. On physical examination, she demonstrates active extension at the distal interphalangeal joint with the PIP joint held in 90 degrees of flexion. Which of the following structures is most likely injured in this patient?
A) Central slip
B) Lateral bands
C) PIP collateral ligaments
D) Terminal tendon
E) Volar plate
A. Central slip
A central slip avulsion will often lead to attenuation of the triangular ligament and volar migration of the lateral bands, which become proximal interphalangeal (PIP) joint flexors. This leads to a boutonnière deformity. However, this may take days to weeks to occur, and acutely, the lateral bands may remain able to weakly extend the PIP joint. The Elson test is useful to determine the integrity of the central slip in this acute stage.
This examination shows a positive Elson test, by which the patient is able to actively extend the distal interphalangeal (DIP) joint as a result of disruption of the central slip. An uninjured finger will not actively extend at the DIP joint with the PIP joint held in flexion, but with injury to the central slip, the lateral bands dissociate and extend the DIP with the PIP joint in flexion
An 18-month-old male infant is brought to the office for evaluation of a Blauth Type II hypoplastic thumb deformity. Physical examination of the right hand shows a narrow first web space and weak opposition. Valgus stress testing shows instability of the metacarpophalangeal (MCP) joint of the thumb. Which of the following is the most appropriate treatment to address the MCP joint instability in this patient?
A) Arthrodesis
B) Extensor indicis proprius tendon transfer
C) Pollicization of the index finger
D) Serial splinting
E) Ulnar collateral ligament reconstruction
E. ulnar collateral ligament reconstruction
A Blauth Type II hypoplastic thumb deformity includes a narrow first web space, thenar muscle insufficiency, and metacarpophalangeal (MCP) joint instability. Surgical management should attempt to address all of the deficiencies at the same time. The flexor digitorum superficialis tendon of the ring finger can be used to perform an opponensplasty and a ulnar collateral ligament (UCL) reconstruction since the tendon length is typically long enough to perform both simultaneously. The narrow first web space can be addressed by various web space deepening procedures, such as a four-flap Z-plasty.
In the case of multi-directional MCP joint instability or degenerative changes, arthrodesis is a reasonable option. With this patient’s unidirectional valgus instability, however, ligament reconstruction is the preferable option. Index finger pollicization is an option for Blauth Type IIIB through V thumbs, which demonstrate carpometacarpal joint instability. Therapy and serial splinting are components of postoperative management and rehabilitation, but they cannot solve the inherent UCL deficiency. Patients with Blauth Type II thumbs can sometimes also present with a clasped thumb deformity from an absent extensor pollicis brevis tendon. This can be addressed with an extensor indicis proprius tendon transfer
Which of the following best describes the primary functions of the tibialis anterior muscle?
A) Ankle dorsiflexion and eversion
B) Ankle dorsiflexion and inversion
C) Ankle plantarflexion and eversion
D) Ankle plantarflexion and inversion
D. ankle dorsiflexion and inversion
innervated by branches of the deep peroneal nerve. It inserts into the medial cuneiform bone in the foot, and as such is primarily responsible for dorsiflexion and inversion of the foot. Loss of function of the tibialis anterior muscle may result in a foot drop, although other muscles involved in dorsiflexion (such as the extensor hallucis longus or toe extensors) can compensate for loss of tibialis anterior function. The tibialis anterior muscle is not responsible for eversion (which is controlled by the peroneus longus and brevis muscles).
A 50-year-old, right-hand–dominant woman presents because of insidious onset, ulnar-sided wrist pain that has been present for the past 10 years. Ulnar impaction syndrome is suspected. Which of the following x-ray images shown is most appropriate for measurement of ulnar variance in this patient?
A) Carpal tunnel view
B) Clenched fist view
C) Lateral view
D) Oblique view
E) Ulnar deviated view
C. Lateral view
On lateral films, ulnar variance is measured between the most proximal point of the lunate fossa and the most distal articulation of the ulnar head, and studies have shown that this is the most accurate x-ray method of estimating ulnar variance.
Ulnar variance, or the relative difference in length of the ulna compared with the radius, has been implicated in a number of pathologic processes. Positive ulnar variance has been associated with tears of the triangular fibrocartilage complex and ulnar impaction syndrome. Negative ulnar variance has been associated with Kienböck disease and carpal instability.
An 81-year-old woman comes to the office because of pain and dysfunction in the left hand. She reports that after washing her hands, she shook off excess water and felt sharp pain in the metacarpophalangeal joint region of the middle finger of the left hand. On examination, the patient has no difficulty making a fist with her left hand, but on extending her fingers, the middle finger does not have full active extension. The middle finger can be easily extended passively, and she is then able to hold it in a fully extended position without difficulty. Which of the following structures is most likely injured in this patient?
A) Extensor digitorum communis tendon
B) Juncturae tendinum
C) Lateral band
D) Sagittal band
E) Terminal tendon
D. sagittal band
Sagittal band injury, especially involving the middle finger, may present in older patients after seemingly insignificant trauma. Classically, these patients present with painful snapping of the extensor tendon as it dislocates/relocates from its position atop the metacarpophalangeal (MCP) joint. They can also present with difficulty with finger extension because of the extensor tendon displacement into the intermetacarpal space.
Disruption of the lateral band may affect extension of the interphalangeal joints but not the MCP joint. Likewise, injury of the terminal tendon could lead to a mallet finger, with loss of distal interphalangeal extension, but would not affect the MCP joint.
A 27-year-old man comes to the office because of pain that developed in the left hand while rock climbing, during which he experienced a loud pop in the hand. He also reports loss of flexion strength. Physical examination shows bruising and swelling over the palmar aspect of the ring finger. The patient is able to bend the proximal interphalangeal (PIP) and distal interphalangeal joints of the ring finger, and he is able to flex the digit with the remaining fingers held in extension. The PIP and metacarpophalangeal joints are stable and pain-free to stress. X-ray studies do not show fracture or dislocation. Which of the following is the most likely diagnosis?
A) Avulsion of the flexor digitorum profundus
B) Lumbrical muscle tear
C) Midsubstance tear of the flexor digitorum superficialis
D) Pulley rupture
E) Volar plate injury
D. Pulley rupture
common in rock climbers. These injuries typically present with an acute onset of pain and sometimes with a loud popping noise, along with swelling and possibly hematoma. Bowstringing may occur in cases of multiple pulley ruptures, when flexing against resistance.
A 70-year-old man is evaluated because of progressively worsening leg pain with ambulation and a nonhealing wound of the lower leg. Physical examination shows a 2-cm dry, necrotic ulcer on the anterior aspect of the leg. In addition to referral to a vascular surgeon, which of the following is the most appropriate next step in management?
A) Ankle-brachial index test
B) Arteriography
C) Biopsy
D) Culture
E) Debridement
A. ABI
An 82-year-old man who is a retired welder comes to the office with an 18-month history of intermittent pain in the right hand. Physical examination shows warm and well-perfused fingers with tiny discolorations in the nail beds. Photographs are shown. Vascular studies disclose a thrombosed ulnar artery and an aneurysm with digital brachial indices in the 0.9 to 1.0 range. Which of the following treatments is most likely to alleviate the symptoms in this patient?
A) Activity modification
B) Aneurysm excision
C) Daily full-dose aspirin therapy
D) Guyon canal decompression
E) Thrombectomy
B. Aneurysm excision
This patient presents with symptoms and signs (ie, splinter hemorrhages) related to intermittent vascular compromise, likely because of microemboli from the thrombosed ulnar artery, as well as possible intermittent vasospastic episodes.
A 24-year-old man sustains a degloving injury to the dorsal foot. The surgeon uses a free temporoparietal fascia flap and split-thickness skin graft to provide thin coverage with a gliding surface. Which of the following complications is most likely to occur at the flap donor site in this patient?
A) Injury to the temporal branch of the facial nerve
B) Injury to the trigeminal nerve
C) Loss of ability to actively move the ears
D) Temporal alopecia
E) Temporal hollowing
D. temporal alopecia
superficial temporal vessels
A 55-year-old woman is referred to the office because of a slow-growing, painless soft-tissue mass on the volar aspect of the right forearm. She does not report any history of trauma. Physical examination shows a 3-cm firm mass at the volar midline of the distal forearm that is mobile in the transverse direction. The mass does not transilluminate. Percussion of the mass elicits a Tinel sign in the median nerve distribution. MRI demonstrates an eccentric mass of the median nerve that is homogeneously hypointense centrally with peripheral hyperintensity. Which of the following is the most likely diagnosis?
A) Dermatofibrosarcoma protuberans
B) Epidermal inclusion cyst
C) Schwannoma
D) Tenosynovial giant cell tumor
E) Volar ganglion cyst
C. Schwannoma
usually solitary and typically present as a slow-growing, painless soft-tissue mass on the flexor surface of the forearm or hand. Schwannomas are often mobile in the transverse direction but not longitudinally, where they may be tethered in line with a peripheral nerve
Ganglion cysts contain mucin and transilluminate
Dermatofibrosarcoma protuberans (DFSP) is an uncommon low-grade malignant skin tumor that arises in the dermis and may be located in the forearm, but rarely in the hand. It usually presents as a painless plaque or nodule with a red-brown or violet color
Tenosynovial giant cell tumors, which include giant cell tumors of the tendon sheath and pigmented villonodular synovitis, are benign soft-tissue tumors. They are the second most common tumor in the hand. These tumors generally occur on the volar surface of the fingers and hand. They present as a firm, nodular, nontender mass commonly located on the three radial fingers.
epidermal inclusion- firm painless mass at tip
A 40-year-old man comes to the clinic because of difficulty with the use of his right hand. Six weeks ago, he was treated at the emergency department after sustaining multiple stab wounds to the right upper extremity. At that time, the wounds were irrigated and closed. Physical examination shows clawing of the small and ring fingers and hyperextension of the metacarpophalangeal joint of the thumb. Sensation is decreased over the palm but normal over the dorsum of the hand. Injury to which of the following nerves is the most likely explanation for these findings?
A) High median
B) High ulnar
C) Low median
D) Low ulnar
E) Radial
D. low ulnar
n low ulnar nerve injuries, the nerve is damaged distal to the motor branch of the flexor carpi ulnaris and motor branch to the flexor digitorum profundus (FDP) of the ring and little fingers. In low injuries, sensation over the palmar ulnar aspect of hand is lost and paralysis occurs, usually to all interosseous muscles, the two ulnar lumbrical muscles, the three hypothenar muscles, the adductor pollicis muscle, and the deep head of the flexor pollicis brevis muscle. Sensation over the dorsum of the hand may be intact if the lesion has occurred distal to the takeoff of the dorsal ulnar sensory nerve, which takes off approximately 5 to 6 cm proximal to the ulnar styloid. The loss of intrinsic muscle function results in an inability to flex at the metacarpophalangeal (MCP) joints and extend the interphalangeal (IP) joints. This results in the development of the intrinsic-minus or claw posture of the ring and little fingers, where there is hyperextension at the MCP joints and flexion at the IP joints (Duchenne sign). The development of clawing does require the presence of intact extrinsic extensor and flexor tendon function; therefore, a high ulnar nerve injury results in less claw hand deformity because of the loss of FDP function.
median nerve injury
In low median nerve injuries, patients present with thenar wasting, weak thumb abduction and opposition, and decreased sensation of the volar thumb, index, and middle fingers. Patients with a high median nerve injury will have these same findings, as well as loss of FDP and flexor digitorum superficialis function to the index and middle fingers and loss of flexor pollicis longus function. They will also have weakness of the flexor carpi radialis muscle.
radial nerve injury
The deep branch supplies motor function to the extensor carpi radialis brevis and supinator muscles. The deep motor branch continues as the posterior interosseous nerve, which supplies motor function to the abductor pollicis longus, extensor carpi ulnaris, extensor digiti minimi, extensor digitorum communis, extensor indicis proprius, extensor pollicis brevis, and extensor pollicis longus muscles. The superficial branch of the radial nerve supplies sensation to the dorsal radial hand, as well as dorsal sensation to the thumb, index finger, middle finger, and the radial side of the ring finger. Depending on the location and specific branches involved, radial nerve injury can result in loss of wrist, thumb, and finger extension, as well as dorsal radial hand and finger sensation.
A 25-year-old man presents with the hook nail deformity shown in the photograph. Which of the following techniques will best address the deformity in this patient?
A) Ablation of the germinal matrix
B) Amputation at the distal phalanx level
C) Placement of an allograft under the nail bed
D) Reconstruction of the eponychium with a local island flap
E) Revision of the distal sterile matrix
E. Revision of the distal sterile matrix
A hook nail develops when an amputation to the fingertip occurs and the nail bed is not supported by bone because part of the distal phalanx is removed proximal to the distal end of the sterile matrix. As a result, the nail grows volarly over the tip. Trimming the distal aspect of the sterile matrix to match the length of the distal phalanx would stop the growth of the nail in the volar direction to repair the deformity.
A 40-year-old woman presents with a pigmented streak in the nail of the thumb. Which of the following is the strongest indication for biopsy of the lesion?
A) History of trauma to the thumb
B) Hypertrophic nail growth
C) Petechial hyperpigmentation
D) Presence of pigmentation for 2 weeks
E) Streak crosses the eponychial fold
E. streak crosses the eponychial fold
bunch or excision biopsy.Worrying signs include irregular borders, ulceration, increasing size, lifting of the nail plate, and extension beyond the nail plate. The finding of pigmentation including the surrounding skin (such as crossing the eponychial fold, ie, Hutchinson sign) is highly suggestive of subungual melanoma.
Hypertrophic nail growth with splitting of the nail is more suggestive of onychomycosis. Petechiae-like hyperpigmented lesions in multiple nail beds are suggestive of Peutz-Jeghers syndrome.
A 28-year-old man who is a carpenter is evaluated after sustaining a complete amputation of the thumb of the nondominant left hand when using a table saw. The injury resulted in destruction of the carpometacarpal joint. Replantation was attempted but not successful. Pollicization of the uninjured index finger is planned for reconstruction. Which of the following joints of the index finger will best function as the carpometacarpal joint of the reconstructed thumb after pollicization?
A) Carpometacarpal
B) Distal interphalangeal
C) Metacarpophalangeal
D) Proximal interphalangeal
C. MCP
A 25-year-old man comes to the office because of pain in the right hand sustained after striking a wall. Physical examination shows swelling, tenderness, and a bony deformity at the dorsal ulnar aspect of the hand. X-ray studies show dorsal fracture-dislocations of the fourth and fifth carpometacarpal joints. In addition to an axially directed load, which of the following forced movements is the most likely mechanism of injury in this patient?
A) Extension of the wrist
B) Flexion of the wrist
C) Metacarpophalangeal joint extension
D) Pronation of the wrist
E) Radial deviation of the wrist
B. Flexion of the wrist
clenched fist punching a firm surface or a fall. This axially directed load across a flexed CMC joint causes the metacarpal base to be directed dorsally, resulting in a dislocation or fracture-dislocation. There is dorsal and proximal displacement of the metacarpal with disruption of the dorsal CMC ligaments and sometimes a hamate fracture. These are unstable injuries and often require reduction and fixation.
A 25-year-old woman comes to the office because of a slow-growing upper extremity mass. Physical examination also shows numerous smaller lesions and masses scattered over the patient’s body. She reports that her mother has similar lesions. MRI images are shown. Which of the following is the most likely diagnosis?
A) Glomus tumor
B) Hemangioma
C) Lymphatic malformation
D) Plexiform neurofibroma
E) Venous malformation
D. plexiform neurofibroma
neurofibromatosis
Glomus tumors are small masses that can be extremely painful with temperature change and typically affect the distal nail bed or palm
A 54-year-old man is evaluated after sustaining a traumatic ulnar nerve laceration with no intrinsic muscle function. On examination, a Froment sign is noted. Which of the following muscles most likely compensates for the thumb adduction that caused the deformity?
A) Abductor pollicis brevis
B) Abductor pollicis longus
C) Extensor pollicis longus
D) Flexor pollicis brevis
E) Flexor pollicis longus
E. Flexor pollicis longus
When injuries occur proximal to the elbow, the expected motor deficits are in the following muscles: flexor carpi ulnaris, flexor digitorum profundus to the ring and small fingers, hypothenar (opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis), third and fourth lumbrical, dorsal and palmar interosseous, adductor pollicis, and deep head of the flexor pollicis brevis.
A Froment sign is observed when the patient attempts to pinch between the thumb and index finger but is unable to activate the adductor pollicis muscle (ulnar innervated) and compensates by activating the flexor pollicis longus muscle by flexing the interphalangeal joint (median nerve innervated).
A 72-year-old woman with advanced rheumatoid arthritis comes to the office because of a sudden inability to extend the small and ring fingers. On physical examination, she is able to extend the wrist, thumb, and index finger independently. Passive wrist flexion with tenodesis shows no passive extension of the small and ring fingers. Her fingers can be passively placed in extension without difficulty, but she cannot maintain them in that position. Which of the following is the most likely cause of these findings?
A) Radial nerve palsy
B) Sagittal band rupture
C) Subluxation of the metacarpophalangeal joints
D) Trigger finger
E) Vaughan-Jackson syndrome with caput ulnae
E. Vaughan-Jackson Syndrome with caput ulnae
developed rupture of the extensor tendons to the ring and small fingers. An inability to extend the fingers at the metacarpophalangeal (MCP) joint can be caused by radial nerve dysfunction, subluxation of the extensor tendons at the MCP joint with sagittal band incompetence, a trigger finger, or extensor tendon rupture. This patient is able to extend the wrist, thumb, and index finger; therefore, the radial nerve is functioning. If the finger can be positioned in extension and maintained by the patient, then the sagittal band is likely ruptured. If the patient had a trigger finger severe enough to prevent active extension of the fingers, it would not be easy to passively reposition them in extension. If tenodesis with wrist flexion does not result in finger extension, the extensor tendons are likely not in continuity. In patients with rheumatoid arthritis, prominence of the distal aspect of the ulna (ie, caput ulnae) is the most common cause of tendon rupture
A 5-year-old boy is evaluated because of the deformity of the left hand shown in the photograph. Three months ago, the boy fell from a chair, and his parents report that he has been unable to extend his thumb. X-ray studies obtained by his pediatrician showed no fracture or dislocation. Physical examination today discloses a palpable mass at the volar aspect of the metacarpophalangeal joint flexion crease. Which of the following is the most appropriate treatment for this patient?
A) Corticosteroid injections
B) Extensor tendon repair
C) Manipulation with anesthesia
D) Percutaneous transection
E) Surgical incision
E. Surgical incision
trigger finger
A 13-year-old boy is evaluated after undergoing debridement of calcaneal osteomyelitis by the orthopedic team. A photograph is shown. Reconstruction with a sensate anterolateral thigh flap is planned. Which of the following best describes the path of the nerve that should be harvested with this flap?
A) It arises from the common peroneal nerve
B) It branches from the tibial nerve
C) It descends through the fibers of the psoas muscle
D) It passes under the lateral aspect of the inguinal ligament
E) It pierces the gastrocnemius muscle
D. it passes under the lateral aspect of the inguinal ligament
lateral femoral cutaneous nerve- passes under inguinal ligament and can be a site of compression. coapted to sural nerve
gracilis–(motor) obturator nerve
sural nerve pierces gastroc (arises from tibial and common Peroneal n)
The medial plantar artery flap can be harvested as a sensate flap, innervated by cutaneous branches of the tibial nerve. This flap is useful for small defects and would not be suitable for such a large wound.
A 45-year-old man is evaluated because of an enlarging fluctuant mass over the posterior hip. Four months ago, he sustained injuries in a snowmobile accident. At that time, he received treatment for sacral and pubic rami fractures, but no skin injury was noted. The initial CT image is shown. Which of the following is the most likely cause of the deformity in this patient?
A) Fat necrosis
B) Hemorrhage
C) Lymphatic disruption
D) Postoperative seroma
E) Sarcoma
C. lymphatic disruption
morel lesion-the fascia is sheared away from the superficial subcutaneous tissues. This creates a prefascial plane which allows for a potential space to be filled from the leaking disrupted lymphatic vessels and capillaries.
A 24-year-old man presents with an injury to the thumb of his dominant hand that he sustained while skiing. In which of the following positions should the metacarpophalangeal joint be tested to assess for integrity of the proper ulnar collateral ligament?
D. 30 flexion, radial
A 22-year-old man comes to the emergency department with a sharp injury to the lateral cord of the brachial plexus sustained during an altercation. Which of the following examination findings is most likely present in this patient?
A) Intrinsic atrophy
B) Limited wrist extension
C) Loss of shoulder abduction
D) Numbness of the ulnar digits
E) Weak elbow flexion
E. Weak elbow flexion
The lateral cord of the brachial plexus contributes to the musculocutaneous nerve with its continuation of the lateral antebrachial cutaneous nerve, and it provides the sensory portion of the median nerve. Therefore, injury would affect elbow flexion as well as lateral forearm and median sensory innervation.
Loss of shoulder abduction (upper trunk, posterior cord), limited wrist extension (extended upper trunk, posterior cord), and ulnar numbness and intrinsic atrophy (lower trunk, medial cord) would be seen in other patterns of brachial plexus injury.
An 18-year-old man presents with severe weakness and sensory loss from his right shoulder to his hand. He was involved in a motorcycle collision 3 months ago. Physical examination shows scapular winging. X-ray study of the chest shows that the hemidiaphragm is raised. Electrodiagnostic study demonstrates preservation of sensory nerve action potentials. On the basis of the image shown, which of the following (A–E) is the most likely site of injury in this patient?
E.
