Which ONE of the following abnormalities in a distal radial fracture is LEAST likely to require reduction in the ED?
Answer: C: When fractures of the distal radius are manipulated in the ED, all important abnormalities should be identified in the pre-reduction X-rays, corrected during manipulation and checked for adequacy of reduction in post-reduction X-rays. The following abnormalities should be properly corrected:
Reference:
Regarding scapholunate dislocation, which ONE of the following statements is TRUE?
Answer: C Scapholunate dislocation is an easily missed ligamentous injury unless careful attention is directed when reviewing the injured wrist and the X-ray. This injury may occur due to a simple mechanism such as falling on an outstretched hand where the dominant force is extreme dorsiflexion of the wrist. A missed injury could cause osteoarthritis of the wrist with resultant functional impairment, as well as ischaemic necrosis of the lunate (Kienbock disease).
For the radiological identification of the injury, on a PA view of the wrist a widened gap is visible between the two carpal bones. This gap is normally <3 mm in adults and if it is wider it is due to scapholunate dislocation (‘Terry-Thomas sign’). On routine X-ray this increased gap may not be obvious and a clenched fist AP view may be required. This injury may also be associated with rotary subluxation of the scaphoid. This gives a ‘signet ring sign’ over the scaphoid.
Arthroscopy is the gold standard in diagnosing and grading of scapholunate injuries. Sensitivity of MRI is relatively low (63%) and its specificity is 86%.
This injury is treated with closed reduction or open reduction with internal fixation in the OT.
References:
Regarding perilunate dislocation, which ONE of the following statements is TRUE?
Answer: B: Perilunate dislocation belongs to a continuum of ligamentous injuries in the wrist, which include scapholunate dissociation, perilunate dislocation and lunate dislocation. These injuries typically occur with falling on an outstretched hand where wrist hyper-extension is the dominant mechanism. Scapholunate dissociation is generally associated with less severe force, whereas perilunate dislocation and lunate dislocation with their associated carpal bone fractures are due to progressively more severe forces.
The four stages of ligamentous injuries in the wrist are:
Perilunate dislocation is best seen on the lateral view. In this injury the lunate remains in position relative to the distal radius but the capitate is dorsally dislocated. On a normal lateral view four C-shaped curved articular surfaces can be identified. They are distal radius, the proximal and distal articular surfaces of the lunate and the proximal articular surface of the capitate. This arrangement is disrupted because of the dorsal displacement of the capitate. On PA view there is overlap of proximal and distal carpal rows.
This injury can be associated with fractures of multiple carpal bones. Most often a scaphoid fracture/ subluxation or capitate fracture is seen.
On examination, wrist swelling and tenderness are present but gross deformity is surprisingly absent in perilunate dislocation. The patient should be referred to the orthopaedics department for arthroscopy guided or open reduction and stabilization.
Regarding emergent referral for replantation of an amputated digit which ONE of the following condition is NOT an indication?
Answer: A: When a patient presents to the ED with complete amputation of a digit or multiple digits with the amputated parts, the injury should be carefully assessed and the patient should be urgently referred to the relevant surgical specialty involved in replantation. Amputated parts that were subjected to severe crush, severe avulsion, severely comminuted bones and prolonged ischaemia due to improper preservation techniques are generally not suitable for replantation. If a digit is cooled without freezing it may survive for a prolonged period. An amputated finger proximal to the insertion of flexor digitorum superficialis tendon insertion is not suitable for replantation. All other conditions mentioned are definitive indications for referral for replantation. If the digit is partially amputated and still attached to the proximal stump, surgical re-attachment is called revascularization.
In a conscious multi-trauma patient, compartment syndrome of the forearm was diagnosed a few hours after the injury, which included a fracture of the midshaft of radius and ulna. Regarding the initial management of compartment syndrome, which ONE of the following steps is LEAST likely to be beneficial?
Answer: B: Compartment syndrome may occur due to a variety of causes but is most commonly due to fractures of the tibia (40% of the cases) and forearm. Other conditions such as haemorrhage, oedema secondary to ischaemic reperfusion injury, constrictive casts, intraarterial drug injection, extravasation of intravenous contrast and crush injury, all of which can increase intracompartmental pressure, may cause compartment syndrome.
Compartment syndrome is treated with urgent surgical fasciotomy, which is done at the time of clinical diagnosis and/or confirmation of compartmental pressure. At the time of diagnosis any restrictive casts and dressings should be removed. ‘Delta pressure’, which is the pressure difference between diastolic BP and the intra-compartment pressure, has been found to better correlate with potentially irreversible muscle injury. Normal intracompartmental pressure is <10 mm Hg and pressure >30–50 mm Hg is detrimental if left untreated for several hours. Delta pressure equal or <30 mm Hg is commonly used as the critical pressure causing compartment syndrome. It is easy to reach this critical delta pressure in hypotensive trauma patients and therefore they are more prone to irreversible damage due to compartment syndrome. In these patients supporting BP is essential to limit this damage. Elevation of the limb above the level of the heart reduces the perfusion pressure of the limb by reducing the arteriovenous pressure gradient, and this can be detrimental to the limb. Elevation should not be done in compartment syndrome.
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