Wrist Flashcards
In patients with basilar joint arthritis of the thumb, treatment with trapeziectomy alone compared with trapeziectomy with ligament reconstruction and tendon interposition is most likely to result in which of the following?
A) Decreased complication rate
B) Increased risk for recurrent pain
C) Longer recovery time
D) Worse functional outcomes
The correct response is Option A.
Simple trapeziectomy was first described in 1947 and though it is only utilized by a small minority of hand surgeons in the United States as solitary treatment for basilar thumb arthritis, its efficacy has not been demonstrated to be inferior to the more commonly employed trapeziectomy with ligament reconstruction and tendon interposition. Meta-analysis has demonstrated that simple trapeziectomy is equally beneficial in terms of pain relief and function as trapeziectomy with ligament reconstruction and tendon interposition, but results in fewer complications.
A variety of reconstructive techniques have been employed in management of basilar thumb arthritis. Most commonly employed in the United States is the trapeziectomy with ligament reconstruction and tendon interposition utilizing the flexor carpi radialis tendon. Other described techniques include CMC joint implant arthroplasty, partial trapeziectomy with interposition arthroplasty, and thumb metacarpal extension osteotomy for early-stage arthritis. None of these techniques have demonstrated superiority over simple trapeziectomy, and synthetic implants have been associated with significant complications.
2018
A 53-year-old man comes to the office because of a 2-year history of increasing pain of the radial aspect of the right wrist. X-ray studies show scapholunate disruption and arthritis. Which of the following joints is most likely to be affected first by the arthritic degeneration in this patient?
A) Capitolunate
B) Radiolunate
C) Radioscaphoid
D) Radioulnar
E) Scaphotrapeziod
The correct response is Option C.
This patient has early-stage scapholunate advanced collapse (SLAC) wrist. SLAC wrist is generally categorized by the Watson classification, which is a descriptive classification but also helps determine management options.
The Watson classification is as follows:
Stage I: Arthritis between scaphoid and radial styloid
Stage II: Arthritis between scaphoid and entire scaphoid facet of the radius
Stage III: Arthritis between capitate and lunate
While original Watson classification describes preservation of radiolunate joint in all stages of SLAC wrist, subsequent description by other surgeons of pancarpal arthritis (stage IV) observed rare cases in which the radiolunate joint is affected. The radioulnar joint is not affected by SLAC wrist.
2018
A 20-year-old woman comes to the office for evaluation of chronic pain of the right wrist, which is alleviated by nonsteroidal anti-inflammatory drugs (NSAIDs). Osteoid osteoma is suspected on x-ray. Which of the following imaging studies is most likely to confirm the suspected diagnosis?
A) Bone scan
B) CT scan
C) Laser fluorescence angiography
D) Magnetic resonance arthrography
E) Ultrasonography
The correct response is Option B.
Osteoid osteoma is a benign bone tumor that arises from osteoblasts; the principal symptom is focal pain at the site of the lesion.
Multiple studies suggest that CT is the best imaging technique for detection of this tumor. Specifically, CT is best at depicting the nidus, the radiolucent area typical of this tumor type. Within the radiolucent nidus, a central area of high attenuation is often seen, representing mineralized osteoid.
As ultrasound waves do not adequately penetrate bone, this intracortical lesion would not easily be detected by this technique.
Although magnetic resonance (MR) has been used to detect these lesions, it is not as sensitive at detecting the nidus as CT scanning. This is because the nidus, especially if it is small, will have signal similar to cortical bone on MR. Although an arthrogram may detect an intra-articular osteoid osteoma, this is a more unusual entity.
A bone scan may show the lesion, but it is nonspecific and will not confirm the diagnosis.
Laser fluorescence angiography has gained popularity for assessing the perfusion of soft tissues (skin, flaps, etc.), but this technique will not help assess bone or tissues of significant depth, nor can it reliably distinguish tumor from other tissue.
2018
A 19-year-old man comes to the office because of persistent left wrist pain after an ATV accident 4 months ago. Medical history includes cast treatment of a wrist fracture. X-ray study shows a proximal pole scaphoid fracture without arthritic changes or collapse. Which of the following is the most appropriate imaging for assessing the vascularity of the bone fragment in this patient?
A) Angiography
B) CT scan
C) MRI
D) Triple phase bone scan
E) Ultrasonography
The correct response is Option C.
The most appropriate imaging modality is MRI.
This patient has presented with a delayed proximal pole scaphoid fracture/nonunion, which was previously untreated. The primary blood supply to the scaphoid enters distally and travels proximally. As a result, perfusion to the proximal portion of the scaphoid occurs in a retrograde fashion. Fractures of the proximal pole of the scaphoid are located at the furthest distance from the blood supply, and these fragments are at risk for nonunion and avascular necrosis.
MRI (particularly with gadolinium enhancement) would be the best imaging study for evaluating the blood supply to the scaphoid fragment and looking for the presence of avascular necrosis. MRI can also provide anatomical information regarding the fracture. Direct intraoperative visualization of bleeding of the fragment has also been advocated in assessing vascularity.
Angiography can show blood flow patterns, but would not provide anatomic information.
CT scan is useful for detailed anatomic analysis of fractures and assessment of healing, but would be less helpful than MRI in determining avascular necrosis.
Bone scan shows the presence of inflammatory activity and can be used in identifying the presence of occult fractures (high sensitivity, albeit with low specificity), but has low resolution and would not be helpful in determining avascular necrosis.
Ultrasonography has been used in the diagnosis of acute fractures, but would not determine vascularity.
2018
A 40-year-old man comes to the office for evaluation of a nonhealing scaphoid fracture. History includes bone grafting for avascular necrosis of the proximal pole, but there is evidence of nonunion. Carpal collapse and humpback deformity are also noted. Reconstruction with a vascularized medial femoral condyle flap is scheduled. Which of the following arteries provides the blood supply to this flap?
A) Descending genicular artery
B) Lateral circumflex femoral artery
C) Medial circumflex femoral artery
D) Peroneal artery
E) Profunda femoris artery
The correct response is Option A.
The descending genicular artery supplies the medial femoral condyle flap. The descending genicular artery is a branch of the superficial femoral artery. This corticoperiosteal flap has been used with increasing frequency for small bony defects and the treatment of nonunion. A cutaneous component can also be harvested based on a saphenous artery branch.
The anterolateral thigh flap is based off the lateral femoral circumflex artery perforators. The gracilis muscle flap is based off vessels from the medial circumflex femoral artery; perforator flaps can also be designed based off this vascular system. The profunda femoris supplies the posterior thigh flap. The peroneal artery provides the vascular supply to the fibula flap.
2017
A 30-year-old woman comes to the office because of a mass of the dorsum of the wrist for the past 5 months. She reports that the mass occasionally gets larger and then gets smaller. Physical examination shows the mass is mildly tender and transilluminates. From which of the following articulations is this lesion most likely to arise?
A) Pisotriquetral
B) Radioscaphoid
C) Scapholunate
D) Scaphotrapezial
E) Thumb carpometacarpal (CMC)
The correct response is Option C.
The mass in question is most likely a dorsal ganglion cyst of the wrist. Sixty to 70% of ganglion cysts are found in the dorsal aspect of the wrist. Dorsal wrist ganglion cysts usually communicate with the joint by a stalk. This stalk usually originates at the scapholunate interval, but it can also rarely arise from other aspects of the dorsal wrist joint.
Thirteen to 20% of ganglia are found on the volar aspect of the wrist, and they usually arise from the radioscaphoid, scapholunate, scaphotrapezial, or metacarpotrapezial joint, in decreasing order of frequency.
Ganglia arising from the flexor tendon sheath of the hand account for approximately 10%.
2017
A 36-year-old man undergoes rehabilitation following scapholunate ligament repair. Initial range of motion in therapy is planned to allow wrist movement while minimizing the movement between the scaphoid and lunate bones. Which of the following wrist movements is most likely to achieve this goal?
A) Neutral wrist extension to neutral wrist flexion
B) Radial deviation in extension to radial deviation in flexion
C) Radial deviation in extension to ulnar deviation in flexion
D) Ulnar deviation in extension to radial deviation in flexion
E) Ulnar deviation in extension to ulnar deviation in flexion
The correct response is Option C.
The most appropriate motion is from radial deviation in extension to ulnar deviation in flexion.
The dart-thrower’s motion, moving from radial deviation in extension to ulnar deviation in flexion, minimizes the movement between the scaphoid and lunate.
Studies have shown that during movement in this axis, from radial deviation and extension to ulnar deviation and flexion, the bones of the proximal carpal row (scaphoid, lunate, triquetrum), remain practically stationary, and motion occurs primarily through the midcarpal joint. As a result, this is felt to be the primary mechanical axis of movement in the wrist. Rehabilitation with movement in the dart-thrower’s axis will limit movement between the bones of the proximal carpal row and allow wrist range of motion while minimizing stress on a scapholunate repair.
Simulation of radioscapholunate fusion results in preservation of the dart-thrower’s motion, confirming this concept.
The remaining motions listed result in greater intercarpal movement of the proximal row.
2017
A 65-year-old woman comes to the office because of pain at the base of the right thumb. Which of the following is the most appropriate plain x-ray study view for visualizing thumb basal joint subluxation?
A) Bett view
B) Brewerton view
C) Eaton stress view
D) Roberts view
E) Standard lateral view of the thumb
The correct response is Option C.
The Eaton stress view is done with the radial borders of the thumb distal phalanges pressed together. It is a posteroanterior view and assesses laxity of the basal joint as demonstrated by subluxation of the thumb metacarpal on the trapezium.
The Brewerton view is taken with the fingers flat on the x-ray plate with the metacarpophalangeal joints flexed 65 degrees beam angled from a point 15 degrees to the ulnar side of the hand. It shows the metacarpal head and is useful for demonstrating degenerative disease or occult fractures.
Bett (or Gedda) view is characterized as a true lateral view of the trapeziometacarpal joint, perpendicular to the plane of the hand. It is performed as a posteroanterior view, with the hand pronated 30 degrees and the axis of the imaging tube angled 25 degrees distally. The view isolates the trapeziometacarpal joint and is useful for evaluating metacarpal base fractures (Bennett’s fracture).
Roberts view is done with the wrist hyper-pronated and the dorsum of the thumb flat on the plate with an AP view. It is used to evaluate degeneration of the trapeziometacarpal joint but does not show subluxation as the stress view does.
2017
A 23-year-old man comes for evaluation because of pain and swelling of the left wrist 6 hours after he fell onto his outstretched left hand. On physical examination, he has tenderness to palpation in the anatomical snuffbox. An occult fracture is suspected. In addition to standard x-ray study views of the wrist, which of the following x-ray views is the most appropriate to confirm the diagnosis?
A) Anteroposterior view with neutral alignment and the beam angled at neutral
B) Clenched fist view with the wrist at neutral and the beam angled at 30 degrees distal to proximal
C) Lateral view with the wrist flexed 30 degrees and the beam angled 45 degrees distal to proximal
D) Oblique view with radial deviation and the beam angled at neutral
E) Posteroanterior view with ulnar deviation and the beam angled 20 degrees distal to proximal
The correct response is Option E.
The scaphoid oblique view is a posteroanterior (PA) view with the wrist in ulnar deviation and the beam angled 20 degrees distal to proximal. This view often will show scaphoid fractures not seen on standard PA, oblique, or lateral views. The other views would not extend the scaphoid and the scaphoid would not be seen as clearly.
2016
A 59-year-old woman comes for evaluation because of a 7-month history of pain over the radial aspect of the right wrist that is aggravated with forceful gripping. She denies any history of trauma to the hand or wrist. On physical examination, there is tenderness to palpation over the right anatomic snuffbox and thenar eminence. Axial load and shifting of the basal joint does not result in crepitance or pain. Resisted thumb extension at the metacarpophalangeal joint level is not painful. An x-ray study of the wrist is shown. Which of the following is the most appropriate operative management?
A) Arthrodesis of the scaphotrapeziotrapezoid joint
B) Arthrodesis of the trapeziometacarpal joint
C) Hemi-resection of the distal trapezium and tendon interposition
D) Release of the first dorsal compartment
E) Release of the second dorsal compartment
The correct response is Option A.
Scaphotrapeziotrapezoid (STT) arthritis can often be misdiagnosed on initial presentation as basal joint arthritis. The keys to differentiating the two sites of pain include physical examination, which shows tenderness more proximal than the basal joint and absence of pain with a grind maneuver, coupled with imaging showing osteoarthritic degeneration at the STT rather than the trapeziometacarpal level. Treatment for the arthritic pain can consist of resection arthroplasty or arthrodesis. Both techniques can provide good relief of symptoms. Resection arthroplasty often is used when the scapho-trapezoid articulation is relatively preserved. Regardless of technique chosen, the surgeon should address both the scapho-trapezial and the scapho-trapezoid joints during the procedure.
Release of the first dorsal compartment would address de Quervain tenosynovitis, which could present with pain over the anatomic snuffbox. On examination, however, the patient would typically demonstrate pain with the “resisted Hitchhiker” maneuver (resisted extensor pollicis brevis function at the metacarpophalangeal level). Given the negative findings on examination and the STT arthritis noted on imaging, this patient would not likely respond to treatment directed at the first dorsal compartment.
Second dorsal compartment tenosynovitis can present with distal forearm and wrist pain. The location of the pain is typically more proximal in the forearm and localized to the intersection between the muscle bellies of the first compartment tendons and the radial wrist extensors. This patient’s pain is localized to the STT region rather than the second dorsal compartment.
Hemiresection of the distal trapezium and tendon interposition has been used successfully in the management of trapezio-metacarpal arthritis (basal joint arthritis). In this patient, the location of the pain, absence of pain with a “grinding” type maneuver, and the imaging showing preservation of the basal joint argue against directing treatment at the basal joint itself.
For the same reasons that hemiresection of the distal trapezium is a poor choice for this patient, arthrodesis of the basal joint addresses the wrong site of arthritis. X-ray study and physical examination both indicate STT arthritis as the etiology of the patient’s pain.
2016
A 20-year-old man is evaluated after falling on his outstretched hand. Physical examination shows tenderness of the snuffbox. X-ray studies of the wrist show no fracture. Which of the following is the most appropriate initial step in management?
A) Application of a sugar-tong splint
B) Application of a thumb spica splint
C) Application of a volar wrist splint
D) Application of an ulnar gutter splint
E) No treatment is necessary
The correct response is Option B.
The patient described may have a scaphoid fracture that is not apparent on initial x-ray studies. Prudent management involves placement of a thumb spica splint until definitive diagnosis can be made. Repeating x-ray studies in 2 weeks or obtaining further radiologic studies, such as CT scans, can make the definitive diagnosis. Casting would be suboptimal in an acute injury such as this because soft-tissue swelling can cause constriction. Surgical exploration is not warranted at this time. A wrist-control, sugar-tong, or ulnar gutter splint would not adequately immobilize the scaphoid, and therefore, would not be adequate management.
Acute scaphoid fractures can often be missed on initial x-ray studies, with reported sensitivities ranging from 84 to 98%. When clinical suspicion of a scaphoid fracture is high and plain films are negative, the traditional recommendation is for these patients to be immobilized in a thumb spica splint or cast with repeat x-ray studies after about 2 weeks.
Even on the repeated x-ray study after 10 to 14 days propagated by many clinicians in cases of occult fracture, a scaphoid fracture is often missed since the additional sensitivity is low, although in a case of sclerosis, an x-ray study could confirm the suspected diagnosis. Further studies that may confirm the diagnosis include CT scan, MRI, and bone scan.
2015
A 24-year-old man comes to the office because of a scaphoid wrist nonunion with apex dorsal angulation and proximal pole avascular necrosis. A free tissue transfer from the lower extremity is planned. A branch of which of the following arteries supplies the most appropriate flap for this patient?
A) Dorsalis pedis
B) Genicular
C) Lateral femoral circumflex
D) Medial sural
E) Peroneal
The correct response is Option B.
The descending genicular artery is the arterial pedicle for the medial femoral condyle free vascularized osseous corticoperiosteal free flap, or free vascularized bone graft. Scaphoid nonunions with a humpback deformity, carpal collapse, and proximal pole osteonecrosis are difficult to treat. Vascularized bone grafts have been shown to have nearly 2× the union rate of traditional nonvascularized bone grafts. Vascularized corticocancellous bone has the potential to revascularize necrotic bone and can provide structural support for fractures with loss of height of the scaphoid. Studies have shown superior union rates for the medial femoral condyle vascularized bone graft versus pedicled grafts from the distal radius. Anatomical studies show no clinical loss of stability of the femur after flap harvest.
The peroneal artery is the blood supply of the fibular osseous or osteocutaneous free flap. It is generally reserved for head and neck reconstruction and larger defects of the extremities.
The descending branch of the lateral femoral circumflex artery supplies the anterolateral thigh free flap. The dorsalis pedis artery supplies the dorsalis pedis fasciocutaneous flap. The medial sural artery and its perforators supply the medial gastrocnemius muscle, and musculocutaneous and fasciocutaneous flaps. All of these flaps are used for soft-tissue defects alone and are not appropriate for reconstruction of bony defects.
2015
A 39-year-old man comes to the office 3 months after falling 10 feet from a ladder because of persistent radial-sided wrist pain, swelling, decreased grip strength, and a painful clicking in the wrist with moderate activity. Physical examination shows diffuse tenderness of the radial wrist and a painful “clunk” when palpating the scaphoid during radial deviation of the wrist. Initial x-ray studies showed no fracture or dislocation. Recent standard x-ray studies of the wrist show no fracture and normal carpal bone alignment. Which of the following is the most likely diagnosis?
A) de Quervain tenosynovitis
B) Dynamic scapholunate instability
C) Flexor carpi radialis tendinitis
D) Kienböck disease
E) Occult scaphoid fracture
The correct response is Option B.
This patient has dynamic scapholunate instability. These injuries can be difficult to diagnose and require a high index of suspicion. A normal x-ray study at 12 weeks in the setting of these clinical findings suggests there is a disruption of the scapholunate interosseous ligament (SLIL) that is symptomatic only with mechanical loading.
The SLIL is the primary stabilizer of the scapholunate joint, but it is surrounded by multiple secondary stabilizers consisting of the extrinsic wrist ligaments. Normal kinematic motion of the proximal carpal row is controlled by the tough interosseous ligaments. The dorsal component of the SLIL is the primary restraint to distraction, torsion, and translational forces. Disruption of the dorsal SLIL alone will result in changes in wrist mechanics, but the presence of the intact secondary stabilizing ligaments will prevent changes seen on a normal static x-ray study, such as scapholunate dissociation or an increased scapholunate angle.
Stress view x-ray studies, such as the clenched-pencil view, should be obtained when dynamic instability is suspected in the setting of a normal static x-ray study series. These results can be compared with the contralateral normal side. Non-contrast MRI is an advanced imaging modality averaging 71% sensitivity, 88% specificity, and 84% accuracy for SLIL tears. There is improved accuracy with 3.0T MRI machines. Wrist arthroscopy is the gold standard for diagnosis and can be combined with therapeutic procedures such as debridement or thermal shrinkage.
An occult scaphoid fracture should be visible at 12 weeks following the injury. Bone resorption at the fracture site makes the fracture line generally visible within 14 days. If suspicion remains for an occult scaphoid fracture at 2 weeks, additional imaging such as MRI or CT scan is indicated. At 3 months following the injury, any fracture present should be visible and treated as a non-union of the scaphoid.
De Quervain tenosynovitis is defined as tendinitis of the first dorsal extensor compartment. This condition generally presents with pain and tenderness over the radial styloid with a positive Finkelstein test. Tenderness of the carpal bones and carpal bone instability such as a painful “clunk” would not be present. The condition is most associated with repetitive use and not acute trauma.
Kienböck disease involves collapse of the lunate due to vascular insufficiency and avascular necrosis. Etiology is unknown but may involve a combination of anatomic factors and trauma. Early symptoms are similar to a wrist sprain but involve more global wrist pain, loss of dorsiflexion, and tenderness of the dorsal wrist over the lunate. Early stage I disease can have normal x-ray studies but will often show signs of a lunate fracture. Later stage disease shows sclerosis and ultimately fracture or collapse of the lunate.
Flexor carpi radialis (FCR) tendinitis is not a common diagnosis. It presents with wrist pain, crepitus, and point tenderness over the FCR at the wrist flexion crease with flexion and radial deviation. Although it is a cause of radial-sided wrist pain, findings of carpal bone instability on examination are not present.
2015
A 23-year-old man comes for evaluation after falling from a ladder onto the left wrist. A scaphoid fracture is suspected. Initial anterior-posterior, lateral, oblique, and scaphoid-view x-ray studies show no definitive fracture. Which of the following additional imaging studies is most sensitive and specific for detecting the suspected fracture?
A) Arthrography
B) Bone scan
C) CT scan
D) MRI
E) Ultrasonography
The correct response is Option D.
The imaging study that is most sensitive and specific for detecting an acute scaphoid fracture is MRI. Many authors have written about the best secondary imaging study for scaphoid fractures not evident on standard x-ray studies. MRI is the best test considering both sensitivity and specificity, followed by CT scan. The majority of the published data shows bone scan to be the most sensitive but less specific than MRI or CT scan. Ultrasonography is used for evaluation of long bone fractures but is not yet indicated for evaluation of carpal bone fractures.
2014
A 63-year-old man comes to the office because of pain of the right wrist and posttraumatic arthritis after a long-standing scapholunate tear that was untreated. Salvage reconstruction with proximal row carpectomy is planned. Which of the following articular surfaces should be intact in order to perform the procedure?
A) Capitolunate
B) Lunotriquetral
C) Radioscaphoid
D) Scaphotrapezial
E) Trapeziotrapezoid
The correct response is Option A.
The capitolunate articulation should be intact in order to perform proximal row carpectomy.
The patient described has a chronic scapholunate tear, which if left untreated, can lead to the consequences of scapholunate advanced collapse (SLAC) wrist. With ongoing progression, degenerative wrist arthritis and pain result.
Arthritis occurs in a predictable sequence, initially at the radioscaphoid joint, followed by the scaphocapitate joint and the capitolunate joint. The radiolunate joint is typically spared until advanced stages.
Proximal row carpectomy is a salvage wrist procedure that can be used in some cases of SLAC wrist. The proximal carpal bones of the wrist (scaphoid, lunate, and triquetral) are removed, and the capitate head is allowed to rest in the lunate fossa of the radius. In order for this procedure to be successful, the capitolunate joint should be free of arthritis. The patient should have preservation of cartilage on the capitate head and the lunate fossa of the radius, as this forms the new articulation of the wrist.
2014
When considering dislocations of the thumb carpometacarpal (CMC) joint, which of the following is most correct regarding which vector of dislocation would occur with injury to the stabilizing ligament?
The correct response is Option B.
The CMCJ is very important for hand function and plays a key role in pinch and grasp. The increased range of motion inherent to the thumb CMCJ is attributed to the anatomy of the joint. The biconcave saddle shaped articular surface of the CMCJ also provides some inherent stability. Motion allowed by the joint includes flexion, extension, adduction, abduction, circumduction. Stabilizing ligaments and joint capsule further reinforce the joint, thus thumb CMCJ dislocations are rare injuries. These injuries account for less than 1% of hand injuries.
There are five major stabilizing ligaments to the CMCJ: anterior (volar) oblique, ulnar collateral, intermetacarpal, dorsoradial, and dorsal (posterior) oblique. These ligaments are critical stabilizers during motion. The volar oblique ligament and dorsoradial ligaments are considered to be the most important resistive forces in dislocation in cadaver studies. Reports of traumatic thumb CMCJ dislocation have been in a dorsal vector. The volar oblique ligament was originally thought to be the critical resistive ligament; however, recent literature has supported the dorsal complex (includes the dorsoradial and posterior oblique ligaments) are the most critical for restraint of the joint, thus are injured in dorsal dislocations. Timely recognition is important for these injuries as immediate reduction and casting or splinting for 4 to 6 weeks may be adequate to prevent recurrence. However, these injuries are often missed on radiologic examination or may be persistently unstable. Closed reduction and Kirschner wire fixation may be adequate for treatment in persistently unstable injuries. Some authors advocate for open reduction and ligament reconstruction. Delayed treatment especially beyond three weeks will likely require open reduction and ligament reconstruction. These injuries are often missed on x-ray examination as they can be subtle especially in the setting of more obvious trauma. Inadequate treatment puts these patients at increased risk for subsequent posttraumatic osteoarthritis given the joint malalignment.
The radiocarpal and dorsal intercarpal ligaments are wrist stabilizer not thumb CMCJ stabilizers.
2019
A 36-year-old man comes to the office because of a 2-week history of pain of the right wrist after a fall on his outstretched hand. X-ray studies are shown. If this injury is left untreated, which of the following joint surfaces is most likely to develop arthritis first?
A) Capitolunate
B) Lunotriquetral
C) Radiolunate
D) Radioscaphoid
E) Scaphocapitate
The correct response is Option D.
The most likely joint surface to develop arthritis is the radioscaphoid joint. This patient shows evidence of scapholunate ligament tear. There is evidence of widening of the scapholunate interval and increase in the scapholunate angle.
The scapholunate angle is calculated by measuring the angle between a line drawn perpendicular to the distal surface of the lunate and along the axis of the scaphoid on the lateral view. The normal scapholunate angle varies from 30 to 60 degrees. A tear in the scapholunate ligament results in volar flexion of the scaphoid bone and dorsiflexion of the lunate, with a resultant increase in the angle.
If a scapholunate ligament tear is left untreated, a degenerative pattern of changes result. This is known as scapholunate advanced collapse (SLAC) wrist. Over time there is separation of the scaphoid and lunate bones and descent of the capitate into the intervening space.
With scapholunate ligament tears, arthritis occurs in a predictable sequence. This initially begins in the radioscaphoid joint, followed by the scaphocapitate joint and the capitolunate joint. The radiolunate joint is typically spared until advanced stages. The lunotriquetral ligament is intact and arthritis does not occur in this area with SLAC wrist.
2019
A 30-year-old man presents to the emergency department with acute left wrist pain after falling 10 feet from a ladder. X-ray studies of the left wrist are shown. After failed closed reduction, the patient reports tingling that progresses to worsening and constant numbness of the left index and long fingers over the course of 6 hours. Which of the following urgent interventions is most appropriate?
A) Aspiration of the wrist
B) Carpal tunnel release
C) MRI of the wrist
D) Open reduction of the scaphoid
E) Repeat closed reduction
The correct response is Option B.
This patient has a type IV perilunate dislocation, or a true lunate dislocation. This represents a complete disruption of the ligamentous stabilizers about the lunate. These injuries are high energy and can be ligamentous only (lesser arc injuries) or include fractures (greater arc) and are then termed perilunate fracture dislocations. Mayfield et al described the stages of injury progressing from radial to ulnar in a type IV dislocation, including injury of the scapholunate ligament, disruption of the lunocapitate joint, injury of the lunotriquetral ligament, and dislocation of the lunate from its fossa at the radiocarpal joint volarly into the carpal tunnel.
On posteroanterior x-ray study of the wrist, there will be disruption of Gilula’s lines. On lateral x-ray study, a “spilled teacup” sign is seen.
Closed reduction with relaxation and traction is important, as the lunate needs to be relocated to its fossa to restore relative alignment of the wrist and to decompress the median nerve in the carpal tunnel. Surgical intervention can then be performed for open reduction of the joints and ligament repair after swelling has improved. However, progression in median nerve symptoms in the setting of successful or failed closed reduction is indicative of acute carpal tunnel syndrome and necessitates urgent surgical intervention.
Advanced imaging such as MRI is not required but may be helpful. Repeat closed reduction is likely to fail at this time, may worsen the swelling, and is unlikely to resolve the carpal tunnel symptoms. Open reduction of the scaphoid is not emergent, and the patient does not have a scaphoid fracture. Aspiration of the wrist will not resolve the inciting etiology of the patient’s carpal tunnel symptoms.
2020
A 21-year-old man is evaluated after he fell onto his outstretched hand while snowboarding, resulting in edema and pain of the wrist. On the basis of examination, the plastic surgeon suspects a scapholunate ligament injury. Which of the following is the most appropriate x-ray study for evaluation of the suspected injury, and what finding would be considered abnormal?
The correct response is Option B.
Scapholunate injuries frequently occur following falls onto an outstretched hand or other wrist trauma. Patients may develop pain and edema about the wrist, and physical examination should include a scaphoid shift test. In the setting of a scapholunate injury, lateral views of plain x-ray studies often demonstrate a scapholunate angle greater than 60 degrees (normal range, 30 to 60 degrees), and clenched fist views frequently demonstrate a scapholunate diastasis greater than 2 mm. A scapholunate interval of 1.5 mm is normal, and the scaphocapitate interval is not used for determination of a scapholunate ligament injury. Additional imaging modalities include MRI and diagnostic arthroscopy.
2021
A 40-year-old man fell on his outstretched right wrist while snowboarding 12 months ago. His injury is displayed in the posteroanterior view of the right wrist on the x-ray study shown. Assuming a pattern of dorsal intercalated segment instability, a lateral view of the wrist is most likely to show the lunate bone in which of the following positions relative to the adjacent carpal bones?
A) Lunate anatomic, scaphoid extended
B) Lunate extended, scaphoid flexed
C) Lunate flexed, scaphoid extended
D) Lunate flexed, triquetrum anatomic
E) Lunate flexed, triquetrum extended
The correct response is Option B.
The posteroanterior x-ray study of the right wrist demonstrates static scapholunate (SL) dissociation with more than 3 mm of widening between the scaphoid and lunate bones. In a normal wrist, with radial to ulnar deviation of the wrist, the proximal carpal bones go into flexion then extension. With ulnar deviation, the hamate bone pushes the triquetrum into relative extension, while the scaphotrapezium-trapezoid (STT) ligament pulls the scaphoid into extension. The lunate follows the direction of its counterparts. With radial deviation, loading across the STT joint pulls the scaphoid into flexion; the lunate and triquetrum follow while translating dorsally and pronating.
When there is complete dissociation between the scaphoid and lunate, the dorsal SL ligament and secondary stabilizers (such as the dorsal intercarpal ligament) have failed. Dorsal intercalated segment instability (DISI) describes the abnormal position of the lunate relative to the long axis of the radius. Secondary to the loss of the SL and associated stabilizers, the scaphoid falls into a position of flexion and pronation, while the triquetrum pulls the lunate into the triquetrum’s preferred position of extension given the intact lunotriquetral ligament. Additionally, the lunate’s configuration with a narrower dorsum and volarly inclined radial joint surface plays a role. Volar intercalated segment instability (VISI) describes the pattern of lunate flexion with disruption of the lunotriquetral ligament; the lunate is pulled into flexion with the scaphoid while the triquetrum falls into its normal tendency to extend. The dorsal radiocarpal ligament has been implicated as well in VISI pattern deformity.
2021
A 28-year-old man presents to the emergency department with acute pain in the left wrist after a motorcycle collision. X-ray studies of the left wrist are shown. Which of the following ligaments maintains its attachment to the lunate?
A) Dorsal intercarpal
B) Lunotriquetral
C) Radioscaphocapitate
D) Scapholunate
E) Short radiolunate
The correct response is Option E.
This patient has type IV perilunate dislocation, or lunate dislocation. This represents a complete disruption of the ligamentous stabilizers about the lunate except for the maintained short radiolunate ligament that the lunate rotates on. These injuries are high energy and can be ligamentous only (lesser arc injuries) or include fractures (greater arc injuries), and they are then termed perilunate fracture dislocations. The mechanism of injury involves wrist extension, ulnar deviation, and intercarpal supination. Mayfield described the stages of injury progressing from radial to ulnar in type IV dislocation, including disruption of the scapholunate ligament and radioscaphocapitate ligament, disruption of the lunocapitate joint, disruption of the lunotriquetral ligament, dislocation of the lunate from its fossa at the radiocarpal joint volarly into the carpal tunnel, and disruption of the dorsal radiocarpal ligament. The volar location of the lunate implies a rupture of any dorsal attachments. On the posteroanterior view of the x-ray study of the wrist, there will be disruption of Gilula lines. On a lateral x-ray study, a “spilled teacup” sign is seen.
2021
Following a fall 2 hours ago, a 23-year-old man reports increasing tingling and pain in the left thumb and index finger. X-ray studies of the left wrist are shown. Attempts at reduction fail. Which of the following is the most appropriate next step in management for this patient?
A) Closed reduction and percutaneous pinning
B) Exploration and wrist arthrodesis
C) External distractor placement
D) Open reduction and internal fixation
E) Proximal row carpectomy
The correct response is Option D.
This patient has sustained a Mayfield III greater arc perilunate injury. The x-ray studies show a scaphoid waist fracture along with a disruption of Gilula’s lines. The lateral view shows the lunate in its fossa with the remaining carpus displaced dorsally. In a closed injury, attempted reduction in the emergency department, often accompanied by sedation, is an appropriate first step. If reduction is successfully performed and the patient has minimal median nerve symptoms, they can be safely discharged home with plans to return within the week for repair. If reduction is not possible, as in this case, then the patient should be admitted to the hospital for open reduction and internal fixation in the form of screw fixation of the scaphoid fracture and scapholunate ligament tear versus K-wire fixation.
In this case, given the patient’s worsening median nerve compression symptoms, acute carpal tunnel syndrome should be considered, and a carpal tunnel release should be performed concurrently with the open reduction and internal fixation. If the resources are not available to perform definitive repair of the bone and joint injury, acute carpal tunnel release is still needed to preserve viability of the median nerve. If the nerve and bony procedures can be done concurrently, by using the volar approach, the carpal tunnel can be easily accessed and released during the approach to reach the displaced lunate. Following this, often a dorsal approach is used to address concurrent scaphoid injuries.
Proximal row carpectomy is reserved for those missed injuries with chronic pain and instability. This patient presents with an acute injury so this would not be recommended. Similarly, wrist arthrodesis is also reserved for chronic injuries in those who have painful and unstable joints, but this would also be a poor choice in this patient.
While some authors use staged reconstruction with a distractor to address soft tissue shortening in late presentations, the two-stage approach would not be necessary in an acute injury like this.
Closed reduction and percutaneous pinning would be difficult since reduction attempts in the emergency department have been unsuccessful, and it would not address the carpal tunnel.
2022
A 65-year-old male laborer presents with worsening pain in the left thumb. An x-ray study is shown. Which of the following is the most important ligament to prevent radial subluxation of the first metacarpal at the carpometacarpal joint?
A) Anterior oblique
B) Dorsal central
C) Posterior cruciate
D) Transverse metacarpal
E) Ulnar collateral
The correct response is Option A.
This patient presents with severe osteoarthritis of the carpometacarpal (CMC) joint of the thumb. The thumb metacarpal is in adduction, and the proximal phalanx is in hyperextension. The complex range of motion of the thumb basal joint is achieved through stability from 16 ligaments. Of the choices given, only the anterior oblique ligament is in the thumb at the basal joint. It has been found to be the most important preventative measure against radial subluxation in cases of CMC arthritis in biomechanical studies. It originates on the volar tubercle of the trapezium and inserts on the thumb metacarpal volarly. In cases of severe thumb CMC arthritis, the progressive ligamentous incompetence of the anterior oblique ligament and dorsal radial ligament allow the thumb metacarpal to migrate dorsally and proximally. The dorsal radial ligament is also important for basal joint stabilization, while the other ligaments of the thumb basal joint are not as important.
The ulnar collateral ligament is located at the metacarpophalangeal (MCP) joint of the thumb, and rupture leads to instability of that joint as seen with gamekeeper’s thumb. The dorsal central ligament is not involved in CMC joint subluxation. The deep transverse metacarpal ligaments are located in the hand between the metacarpal heads and assist in supporting the metacarpal arch. The posterior cruciate ligament helps stabilize the knee by preventing the tibia from slipping posteriorly when flexed.
2022
A 55-year-old laborer presents with radial-sided wrist pain and swelling with activities. A 6-month course of splinting, activity modification, and nonsteroidal anti-inflammatory drugs failed to relieve his symptoms. A wrist x-ray study is shown. Which of the following is the most appropriate surgical option for durable reconstruction in this patient?
A) Scaphocapitate arthrodesis
B) Scaphoidectomy with four-corner arthrodesis
C) Scaphoid open reduction and internal fixation
D) Scapholunate ligament reconstruction
E) Scaphotrapeziotrapezoid arthrodesis
The correct response is Option B.
This patient presents with a scaphoid nonunion advanced collapse arthritis pattern (SNAC). The arthritic pattern follows a pattern very similar to scapholunate advanced collapse (SLAC). Watson and Ballet (JHS, 1984) recognized that chronic scapholunate ligament incompetence led to a predictable sequence of arthritic wear at the radioscaphoid junction (scapholunate advanced collapse [SLAC] stages I and II), later progressing to involve the midcarpal joint (SLAC stage III), usually sparing the spherical radiolunate articulation. Four-corner arthrodesis (capitate-lunate-triquetrum-hamate) with scaphoid silicone prosthetic replacement (silicone replacement later omitted) was Watson and Ballet’s recommended surgical treatment and preferred over proximal row carpectomy.
The SLAC pattern of arthrosis is thought to be due to traumatic injury to the scapholunate ligament. Calcium pyrophosphate dehydrate crystal deposition disease (CPPD, or pseudogout) has been reported to be a frequent cause of SLAC-type x-ray changes as well. Scaphoid fracture nonunion can lead to a similar degenerative arthritic pattern of the wrist, called scaphoid nonunion advanced collapse (SNAC).
Symptomatic treatment with splints, modalities, and injection may suffice in many patients. There are no studies on the long-term success of nonsurgical treatment for SLAC or SNAC wrist, nor are there any long-term natural history studies. Surgical treatment options for either SLAC or SNAC wrist include partial or complete wrist arthrodesis, proximal row carpectomy (PRC), denervation, or radial styloidectomy. SNAC wrist has the additional potential treatment option of excision of the distal ununited scaphoid fragment. Most studies concerning treatment of SLAC/SNAC wrist have focused on the results of four-corner arthrodesis with scaphoid excision or PRC. Controversy exists concerning whether PRC, or a modification thereof, may be performed when the capitate has arthritic changes.
Scaphocapitate arthrodesis, with resection of the lunate, is a treatment option for late-stage Keinböck disease. Scaphocapitate arthrodesis leaves the radioscaphoid joint in place, making it inappropriate for the patient in this case who has radioscaphoid arthritis. Open reduction and internal fixation of the scaphoid is not indicated here, since the arthritic change noted on x-ray study is the sequela of an old scaphoid fracture nonunion, which has now gone on to advanced collapse arthritis. There does not appear to be too much arthrosis in the scaphotrapeziotrapezoid (STT) joint, with the more likely source of the patient’s pain related to the radiocarpal joint, so an STT fusion would not be indicated here. This arthrosis is the result of a chronic scaphoid nonunion with subsequent carpal collapse, so repair of the SL ligament would not be indicated.
2022
