Full Chapter Flashcards
(190 cards)
1
Q
What is a risk factor for the development of compartment syndrome after a supracondylar fracture?
A
Excessive swelling combined with delay in treatment.
2
Q
What is one initial step in managing a suspected evolving compartment syndrome?
A
Removing all circumferential dressings.
3
Q
According to Battaglia et al., what is the relationship between elbow flexion and volar compartment pressure?
A
Increasing elbow flexion above 90 degrees increases volar compartment pressure.
4
Q
What is recommended for immediate stabilization in cases of suspected compartment syndrome after a fracture?
A
Stabilization with Kirschner wires to allow proper management of soft tissues.
5
Q
How does warm ischemic time after injury contribute to the development of compartment syndrome?
A
Muscle ischemia is possible, depending on the time of oxygen deprivation.
6
Q
When should prophylactic volar compartment fasciotomy be considered?
A
It can be considered at the time of arterial reconstruction.
7
Q
What was found to be of some value even when the diagnosis of compartment syndrome is delayed or chronic?
A
Fasciotomy.
8
Q
What suggests critical ischemia in a child with a ‘pink pulseless hand’ following fracture reduction?
A
Persistent and increasing pain.
9
Q
What is the most common nerve injury in extension-type supracondylar fractures?
A
AIN (5%).
10
Q
What nerve injuries were reported in the largest single-center study of type III supracondylar fractures?
A
12% nerve injuries at presentation, with a rate of 19% if associated forearm fracture required reduction.
11
Q
What does a prospective study on nerve injuries in operatively treated supracondylar fractures suggest?
A
A trend between fracture severity and rate of preoperative nerve injury.
12
Q
What was seen in the same study regarding the relationship between fracture severity and nerve injury rate?
A
Type II 7%, type III 19%, type IV 36%.
13
Q
What potential nerve entrapment issue may occur during reduction of supracondylar fractures?
A
Median nerve and/or brachial artery may be trapped within the fracture site.
14
Q
What technique is used to forcibly milk the biceps during the reduction of fractures?
A
“Milking maneuver” is used to force biceps past the proximal fragment.
15
Q
How many pins are generally recommended for type II and type III fractures?
A
A minimum of two pins for type II fractures and three pins for type III fractures.
16
Q
What is more critical in pin placement for fractures, pin separation, or pin orientation?
A
Pin separation is more important than whether the pins are divergent or parallel.
17
Q
What should be ensured to correctly place a pin for fracture fixation?
A
Ensure the pin goes through the proximal cortex and engages the proximal fragment.
18
Q
What should be done to verify the correct placement of K-wires before advancing with drilling?
A
Push K-wires into the cartilage in desired location and trajectory, verify with imaging.
19
Q
What is the recommended elbow position during fixation to improve stabilization?
A
The elbow should be sufficiently flexed so that the fingers touch the shoulder.
20
Q
What is the alternative approach if maintaining fracture reduction becomes difficult during imaging?
A
Move the C-arm instead of the patient’s arm during imaging.
21
Q
In what instance would a medial pin be considered in fracture stabilization?
A
If three lateral pins do not stabilize the fracture, or there is an oblique fracture pattern.
22
Q
What precaution should be taken when placing a medial pin to avoid nerve damage?
A
Extend the elbow when placing the pin to keep the ulnar nerve posteriorly out of harm’s way.
23
Q
Why is it recommended to save images where reduction looks the worst postoperatively?
A
To compare during visits and determine if any movement or malreduction occurred.
24
Q
What are the considerations for treating SCH fractures nonsurgically?
A
Likelihood of follow-up with an orthopedic surgeon for timely rereduction.
25
How does insurance status impact follow-up rates for SCH fractures?
Children with public or no insurance are almost three times less likely to follow up.
26
What are the results of closed reduction and percutaneous pinning for type II fractures?
No radiographic or clinical loss of reduction, cubitus varus, hyperextension, or loss of motion.
27
What are the reported complications of closed reduction and percutaneous pinning for type II fractures?
2% pin-tract infections, successfully treated with antibiotics and limited surgical interventions.
28
Why is operative treatment advocated for type II SCH fractures?
Hyperflexion needed for reduction in unpinned fractures raises compartment pressure risk.
29
What is the role of flexion in maintaining reduction for SCH fractures?
Elbow flexion >90 degrees increases neurovascular compromise risk; should be immobilized with pins.
30
Why is pinning recommended for type III SCH fractures?
Operative reduction and pinning produce better results compared to non-surgical methods.
31
What role does the periosteum play in extension-type SCH fractures?
The intact posterior periosteal hinge provides stability and facilitates fracture reduction.
32
Why should flexion of the elbow be limited for type III fractures?
Flexion up to 90 degrees increases risk of compartment syndrome, requires caution.
33
O que deve ser colocado primeiro antes de usar um pino medial?
Lateral pins
34
Por que razão o pino medial deve ser colocado sem hiperflexão do cotovelo?
To avoid hyperflexion of the elbow
35
De acordo com estudos biomecânicos, qual configuração de pino foi encontrada como mais forte do que dois pinos laterais?
Crossed pins
36
How should lateral pins be separated at the fracture site for optimal stability?
Clinically recommended to be separated at the fracture site
37
Nos estudos de Lee et al., qual técnica de fixação foi considerada superior em carga de extensão e varo?
Divergent: two divergent lateral pins
38
Bloom reportou que a força de três pinos divergentes de entrada lateral é superior à da travagem cruzada.
Three lateral entry divergent pins were equivalent and stronger
39
A maioria dos estudos biomecânicos contemporâneos apoia principalmente a configuração de pinos transversais para fixação de fraturas.
Lateral entry pins
40
Quais são os pontos técnicos importantes para a fixação com pinos de entrada lateral de acordo com uma série bem-sucedida de fraturas?
Maximize pin separation, engage medial and lateral columns, engage sufficient bone, consider a third pin for stability, use three pins for type III fractures
41
What were the identified pin-fixation errors by Sankar et al. that led to loss of fixation?
Failure to engage both fragments, failure to achieve bicortical fixation, failure to achieve adequate pin separation
42
Quais equipamentos são comumente usados na redução fechada e na fixação percutânea?
0.062-in smooth K-wires, sterile coban, sterile felt, sterile foam
43
Como deve o paciente ser posicionado para redução fechada e fixação percutânea?
Supine on the operating table with fractured elbow on a short radiolucent arm board
44
Quais são alguns passos cirúrgicos chave na redução fechada e fixação percutânea?
Prep and drape, traction, fracture reduction, check reduction, place K-wires, place pins, bend and cut wires
45
How should the elbow be positioned during traction to avoid tethering neurovascular structures?
Flexed at about 20 degrees
46
How long should significant traction be held for badly displaced fractures to allow soft tissue realignment?
60 seconds
47
How is varus and valgus angular alignment corrected in closed reduction and percutaneous pinning?
By movement of the forearm with the elbow almost straight
48
How is medial and lateral fracture translation realigned in closed reduction and percutaneous pinning?
With direct movement of the distal fragment by the surgeon with image confirmation
49
What should be allowed for recovery of perfusion in the operating room before deciding to explore the brachial artery?
Up to 10 to 15 minutes.
50
Why is the absence of a pulse alone not an indication for exploring a brachial artery?
Most patients without a palpable pulse regain and maintain adequate distal perfusion.
51
What is imperative for hand viability in cases of poorly perfused hands?
Exploration is imperative for all poorly perfused hands.
52
What is the risk associated with prolonged poor or absent pulse and poor perfusion during fracture reduction?
High risk of compartment syndrome.
53
What should be considered in cases of poor limb perfusion lasting over 6 hours?
Prophylactic forearm compartment release should be considered.
54
What should be done if a pulseless hand remains poorly perfused following reduction and pinning?
Arterial exploration should be performed emergently.
55
What measures may relieve associated arterial spasm following freeing the artery from the fracture?
Application of lidocaine, warming, and 10 to 15 minutes of observation.
56
What is indicated if the hand remains poorly perfused after anatomic fracture reduction and decompression of the NVB?
Vascular reconstruction by an appropriate specialist.
57
What is recommended if a pulse does not return but the hand is well perfused post-reduction?
Admitting the child to the hospital with observation for at least 48 hours.
58
What is considered as an objective sign of good perfusion in the context of a well-perfused yet pulseless hand?
Presence of a triphasic pulse detectable on Doppler.
59
Why is it recommended to take a true AP view of the distal humerus during radiographic examination of elbow fractures in children?
To allow a more accurate evaluation of the distal humerus and decrease errors in determining Baumann's angle.
60
What percentage of accuracy has been reported for emergency room physicians' interpretation of elbow fractures in children?
53%
61
What is the significance of the lateral film being taken as a true lateral during radiographic examination of elbow fractures?
It helps with accurate evaluation without external rotation, especially in determining Baumann's angle.
62
When should oblique views of the distal humerus be taken during radiographic examination of elbow fractures in children?
Occasionally when supracondylar or occult condylar fractures are suspected but not seen on standard views.
63
What are the main radiographic parameters used to evaluate the presence of a supracondylar fracture?
The anterior humeral line (AHL) crossing the capitellum on a true lateral of the elbow.
64
What is the normal range for Baumann's angle, also known as the humeral capitellar angle?
About 9 to 26 degrees.
65
How does the anterior humeral line (AHL) differ in children under 10 years of age compared to children 5 years and older?
In children under 10, AHL only passes through the capitellum's middle third 52% of the time, while in children 5 and older, it should always pass through the center.
66
How should supracondylar fractures be initially splinted?
With the elbow in a comfortable position of 20 to 40 degrees flexion.
67
What action may restore a pulse if the arm is pulseless?
Gentle traction and elbow flexion alone may frequently restore a pulse.
68
What complications may arise from excessive flexion or extension of the elbow during splinting?
Compromise of the limb's vascularity and increased compartment pressure.
69
What is the recommended position for the elbow and hand after initial splinting?
They should be gently elevated above the heart.
70
According to the course notes, what percentage of Pediatric Orthopaedic Society members would treat a type III supracondylar humerus fracture by splinting overnight if there were no emergent issues?
81% would treat by splinting overnight and fixing the following morning.
71
In the study by Larson et al., what percentage of type II supracondylar fractures had surgery more than 24 hours after injury?
52% had surgery more than 24 hours after injury.
72
When is operative treatment not unduly delayed for supracondylar fractures according to the notes?
It should not be unduly delayed if poor perfusion, pulselessness, firm compartments, etc., are present.
73
What timing for operative treatment of type II supracondylar fractures did Larson et al. find did not affect outcome?
Timing for operative treatment did not affect outcome.
74
What did Silva et al. find regarding closed reduction of type II supracondylar fractures treated 7 to 15 days after injury?
They found that closed anatomic reduction was achieved with equal outcomes to fractures treated within 7 days of injury.
75
Why is reliable fracture reduction after 2 weeks less likely in very young children?
Due to early callus formation making reduction less likely.
76
How is perfusion evaluated post-fracture reduction in the operating room?
Skin color is evaluated and a Doppler is used to assess for a triphasic pulse.
77
What is the management approach for a poorly perfused hand following reduction?
Open exploration and decompression or repair of the artery is required.
78
What action should be taken if a hand becomes poorly perfused immediately after reduction and pinning?
Remove pins immediately, allow the fracture to return to its unreduced position, and consider open exploration of the artery.
79
What should be done if there is no pulse postoperatively in an arm without a pulse preoperatively?
Prolonged observation for 48 hours with the arm mildly elevated is preferred.
80
What steps are involved in the Open Reduction and Pinning Technique?
Expose, retract muscle to identify neurovascular bundle, remove periosteum, reduce fracture, repair/reconstruct artery, release forearm compartments.
81
Where should an incision be made for exposure in the Open Reduction and Pinning Technique?
A 4 to 5 cm transverse anterior incision above and parallel to the antecubital fossa at the fracture site.
82
When should forearm compartments be released in the Open Reduction and Pinning Technique?
Forearm compartments should be released to prevent reperfusion compartment syndrome with arterial reconstruction.
83
What is the significance of decreased elbow crossing the anterior third of the capitellum?
It is associated with less elbow flexion compared to crossing the middle or posterior third.
84
Why is the elbow casted in significantly less than 90 degrees of flexion?
To ensure that the pins, not the cast, are holding the reduction.
85
What should be evaluated if there is any question of perfusion postoperatively?
Skin color should be examined, and Doppler assessment for a triphasic pulse should be undertaken.
86
In Open Reduction and Pinning, what care must be taken during dissection to avoid damage?
Care must be taken as the NVB may be superficial and pushed against the skin, risking damage.
87
What should be done if an avascular or dysvascular hand is encountered in a fracture site?
The NVB needs to be gently teased out of the fracture without harm.
88
Why is it important to release forearm compartments if revascularization is required?
To lessen the risk of reperfusion compartment syndrome.
89
How can the brachialis muscle interposition be utilized in a fracture?
The 'milking maneuver' frees the muscle, allowing closed reduction to occur.
90
What is the predictive indicator of the need for arterial repair and risk of compartment syndrome?
Hand perfusion, not the presence or absence of a pulse.
91
What are the generally accepted criteria for distinguishing a viable hand upon presentation?
Capillary refill equivalent to the opposite side in less than 3 to 5 seconds, normal pulp turgor, and pink color.
92
What type of injury involves forced elbow hyperextension?
Extension-type fractures of the distal humerus.
93
How do extension-type fractures typically occur in children?
Most children attempt to break falls with extended arms, leading to hyperextended elbows.
94
What is the result of the distal humerus failing anteriorly in extension-type fractures?
Potential harm to adjacent soft tissue structures like the brachialis muscle, brachial artery, and median nerve.
95
What determines the risk to different soft tissue structures in supracondylar fractures?
Medial or lateral displacement of the distal fragment.
96
What is the anatomical variant that can be the site of median nerve compression?
Supracondylar process.
97
How does ligamentous laxity relate to predisposition for extension-type SCH fractures?
It's unclear if ligamentous laxity with elbow hyperextension predisposes to SCH fractures.
98
What determines which soft tissue structures are at risk in SCH fractures?
Whether the distal fragment is medially or laterally displaced.
99
What is recommended for patients with a history of a fall and inability to use the extremity?
A thorough radiologic evaluation, including AP and lateral views of the upper extremity.
100
How does forearm pronation aid in fracture reduction?
Forearm pronation places the medial and posterior periosteum on tension, correcting varus and extension malalignment and adding stability.
101
What is recommended for reduction in a posterolaterally displaced supracondylar fracture?
Forearm supination in addition to flexion is recommended for reduction in a posterolaterally displaced supracondylar fracture.
102
What is the significance of medial column comminution fractures?
Fractures with medial comminution must be treated with operative reduction to prevent varus deformity.
103
How is reduction of a medial comminuted fracture achieved?
Significant valgus force is applied across a straight elbow, with well-placed lateral entry pins for stabilization.
104
What approach is recommended for open supracondylar fractures?
The anterior approach using a transverse incision based on the open wound with medial or lateral extension as needed is recommended.
105
What should be done in cases of open supracondylar fractures?
Open irrigation, debridement, examination of fracture surfaces, washing, and stabilization with K-wires are necessary.
106
What antibiotic treatment is recommended for open fractures per the notes?
Cefazolin for Gustilo type I, II, and IIIA injuries, with additional antibiotics for gram-negative organism coverage.
107
What was the patency rate in 54 patients with surgically repaired arteries?
91%
108
What percentage of patients who had brachial artery ligation as a child for renal transplant had mildly decreased exercise tolerance?
67%
109
What is recommended for evaluating postreduction circulation in patients with a pink pulseless hand?
Pulse oximetry
110
What should be considered if the arm is pulseless and has a median nerve deficit?
Special attention and monitoring for compartment syndrome
111
According to Mangat et al., what was found in patients who were pulseless with a median nerve injury?
Brachial artery trapped or tethered at the fracture site
112
What is the approach for the brachial artery during exploration in a Gartland type III supracondylar fracture?
Anteromedial transverse incision above the antecubital fossa
113
When is formal vascular repair and/or vein grafting required in patients with a nonviable hand post fracture reduction?
When release of a fascial band or an adventitial tether does not resolve the problem
114
What is recommended in patients with pulseless extremities without a nerve deficit?
Exploration of the brachial artery is less likely needed
115
How long is a type II supracondylar fracture managed in a long-arm cast?
Approximately 3 weeks.
116
What is the recommended elbow flexion angle in a long-arm cast for a type II fracture?
Approximately 60 to 90 degrees.
117
When are follow-up x-rays recommended after managing a type II supracondylar fracture in a cast?
At 1 week for assessment of fracture position.
118
What is the authors' preferred fixation method for most type II supracondylar fractures?
Closed reduction and two lateral pins.
119
When is a third lateral pin considered for fixation in type II supracondylar fractures?
If two lateral pins fail to provide acceptable fixation.
120
Why is it safer to hold a type II fracture reduced with pins rather than flexing the elbow greater than 90 degrees?
To prevent displacement of the fracture.
121
What treatment approach is taken for type III supracondylar fractures?
Closed reduction percutaneous pinning (CRPP) attempted first.
122
What is the postoperative care approach for type IV supracondylar fractures according to the authors?
Placement of two K-wires into the distal fragment first.
123
What is used for pain control after supracondylar fracture surgery in children according to Swanson et al.?
Acetaminophen.
124
When are ROM exercises typically taught to the family post-removal of cast?
A few days after cast removal.
125
How is dissection best accomplished along the brachial artery?
Proximally to distally, identifying both the artery and the median nerve.
126
What artery is generally injured at the level of the supratrochlear artery?
The brachial artery, as it becomes vulnerable at this location.
127
What can be done if arterial spasm causes inadequate flow?
Attempts to relieve the spasm or application of papaverine may help.
128
What is indicated in cases of prolonged ischemia to prevent compartment syndrome?
Prophylactic release of forearm fascia.
129
What are the classic five Ps for the diagnosis of compartment syndrome?
Pain, pallor, pulselessness, paresthesias, and paralysis.
130
What are the more sensitive indicators of compartment syndrome in children?
Increasing analgesia requirement and other clinical signs.
131
What are clinical signs of compartment syndrome of the forearm?
Resistance to passive finger movement and dramatically increasing pain.
132
How can iatrogenic ulnar nerve injury be avoided?
By using lateral entry pins and avoiding cross-pins if not necessary.
133
What was the reported iatrogenic neurapraxia rate for laterally placed pins in the meta-analysis?
1.9% for laterally placed pins.
134
After how many days did 90% of range of motion (ROM) return for extension in children with SCH fractures?
30 days.
135
When were pins typically removed following closed reduction percutaneous pinning of supracondylar fractures?
By 3 to 4 weeks.
136
What should be done if elbow motion is not nearly normal at the 4 to 8-week follow-up appointment?
Physical therapy to improve elbow motion should be started.
137
What risk does lateral entry pins pose in terms of infections?
Lateral entry pins can carry a risk of deep-spaced infection.
138
How do pin-tract infections generally resolve?
Pin-tract infections generally resolve with pin removal and antibiotics.
139
What can an untreated pin-tract infection result in?
An untreated pin-tract infection can result in a septic joint.
140
What is the reduction maneuver for posterior laterally displaced fractures?
Supinate the forearm.
141
How should the elbow be positioned during traction for fracture reduction?
With elbow flexed 20 to 30 degrees.
142
What is the role of the assistant during fracture reduction?
Provide countertraction against the patient's axilla.
143
What should be verified through fluoroscopic images after reduction?
Anterior humeral line, Baumann's angle, medial and lateral columns.
144
How should the elbow be taped after a satisfactory reduction?
In the hyperflexed position with elastic tape.
145
Where should the K-wire be placed before advancing it through the skin?
Against the lateral humeral condyle, not piercing the skin.
146
How should the drill be used for advancing the pin after correct placement?
Advance the pin using the drill.
147
What percentage of extension SCH fractures have a nerve injury?
11%
148
What percentage of nerve injuries in extension fractures involve multiple nerves?
14%
149
Which nerve is most commonly injured in extension SCH fractures?
Median nerve
150
Describe the presentation of AIN palsy.
Paralysis of thumb and index finger flexors without sensory changes
151
What are the common causes of complete median nerve injury?
Severe contusion, entrapment, or transection at fracture level
152
In which direction of fracture displacement is the radial nerve more likely to be injured?
Posteromedially
153
Which nerve is most likely to be injured in a flexion-type supracondylar fracture?
Ulnar nerve
154
What is the general approach to nerve recovery in closed fractures?
Observation; may take 6 months or more
155
What is the success rate of nerve grafting for non-continuous nerves?
Successful in restoring nerve function
156
How can pin migration complications be minimized?
Bending at least 1 cm of pin at a 90-degree angle, 1 cm from the skin and using pin covers.
157
What is myositis ossificans and how is it treated?
Rare ossification complication post-fracture. Expects spontaneous resolution; no early excision.
158
What contributes to nonunion in supracondylar fractures?
Infection, devascularization, and soft tissue loss increase nonunion risk.
159
Describe avascular necrosis risk in supracondylar fractures.
Can occur at the trochlea due to fragile blood supply, leading to deformities.
160
What symptoms indicate avascular necrosis of the trochlea?
Mild pain, occasional locking, radiologic findings, and limited motion.
161
How is loss of reduction following fixation treated?
May need medial and lateral column arrests or arthroscopic debridement.
162
What are the potential complications in patients with pulseless supracondylar fractures?
Compartment syndrome and the need for vascular repair.
163
# Epidemiologia
What percentage of patients with pulseless supracondylar fractures had a return of palpable pulse following reduction?
48%.
164
When should urgent reduction with pinning in the operating room be done for a pulseless, well-perfused hand?
In the case of pulselessness but well-perfused hand.
165
What is the suggested elbow flexion angle for repositioning a severely displaced supracondylar fracture with compromised vascularity?
Approximately 20 to 40 degrees.
166
Why should fracture reduction not be delayed for an angiographic study in patients with pulseless supracondylar fractures?
Reduction of the fracture usually restores the pulse.
167
What is the standard treatment for a pulseless hand following supracondylar fracture?
Closed reduction and percutaneous pinning.
168
What is the most common operative treatment for supracondylar fractures?
Closed reduction and pinning.
169
What criteria indicate an acceptable reduction in supracondylar fractures?
Restoration of Baumann's angle, intact medial and lateral columns, and appropriate alignment of the AHL.
170
What is the recommended immobilization degree for the elbow in supracondylar fractures?
40 to 60 degrees of flexion.
171
When should an open reduction be considered in supracondylar fractures?
If there is a considerable gap in the fracture site or if the fracture is irreducible with a 'rubbery' feeling.
172
What are the risks associated with crossed pins in supracondylar fractures?
Potential ulnar nerve injury and risk of loss of reduction.
173
How many pins are recommended for a type III supracondylar humeral fracture?
Three pins
174
What pin spacing is recommended at the level of the fracture to prevent loss of reduction?
At least 13 mm or one-third the width of the humerus
175
What is the recommended minimum number of pins for a type II supracondylar humeral fracture?
Two pins
176
What is indicated in cases of failed closed reduction or nerve injury following reduction?
Open reduction
177
# Epidemiologia
What is the rate of open reductions in specialized pediatric trauma centers at Children's Hospital?
0.7%- 6%
178
What approach is extremely useful for open reduction in cases of neurovascular compromise at the elbow?
Direct anterior approach
179
Name three types of pin-fixation errors identified in the notes.
Failure to engage both fragments, failure to achieve bicortical fixation, failure to achieve adequate pin separation.
180
What did Pennock et al. report as an important factor in preventing loss of reduction?
Pins separated by at least 13 mm at the level of the fracture on an AP view.
181
What deformity is described as 'gunstock deformity'?
Cubitus varus.
182
Describe the appearance of cubitus varus deformity on x-ray according to the notes.
Angle of the physis of the lateral condyle (Baumann's angle) is more horizontal on the AP view.
183
What is Metev's sign?
The appearance of a hole in the bone due to chronic nerve entrapment in healed callus.
184
What is the rate of iatrogenic injury to the ulnar nerve in patients with supracondylar fractures?
Reported to occur in 1% to 15% of patients.
185
Where is the ulnar nerve vulnerable when a medial pin is placed?
Between the medial epicondyle and the olecranon at the cubital tunnel.
186
What are the risks associated with the posterior approach for an extended supracondylar fracture?
Higher rate of loss of motion, further fracture instability, risk of avascular necrosis.
187
How is the intraosseous blood supply of the distal humerus depicted?
The vessels supplying the lateral condylar epiphysis enter on the posterior aspect.
188
What is the recommended duration of immobilization for supracondylar fractures?
3 weeks, regardless of the type (Type I, II, or III).
189
What are the criteria used to determine an acceptable position for a supracondylar fracture?
AHL transecting the capitellum, Baumann's angle, intact olecranon fossa.
190
Why is excessive swelling, nerve or vascular disruption concerning in type I fractures?
Indicative of a more significant injury, periosteal disruption might render the fracture unstable.
