Supracondylar Fractures around elbow Dr. D. N. Bid [PT]
• These are among the commonest fractures in children.• The distal fragment may be displaced either posteriorly or anteriorly.
Mechanism of injury• Posterior angulation or displacement (95 per cent of all cases) suggests a hyperextension injury, usually due to a fall on the outstretched hand.• The humerus breaks just above the condyles. The distal fragment is pushed backwards and (because the forearm is usually in pronation) twisted inwards.• The jagged end of the proximal fragment pokes into the soft tissues anteriorly, sometimes injuring the brachial artery or median nerve.• Anterior displacement is rare; it is thought to be due to direct violence (e.g. a fall on the point of the elbow) with the joint in ﬂexion.
Classification• Type I is an undisplaced fracture.• Type II is an angulated fracture with the posterior cortex still in continuity.• IIA – a less severe injury with the distal fragment merely angulated.• IIB – a severe injury; the fragment is both angulated and malrotated.• Type III is a completely displaced fracture (although the posterior periosteum is usually still preserved, which will assist surgical reduction).
Clinical features• Following a fall, the child is in pain and the elbow is swollen; with a posteriorly displaced fracture the S-deformity of the elbow is usually obvious and the bony landmarks are abnormal.• It is essential to feel the pulse and check the capillary return; passive extension of the ﬂexor muscles should be pain-free.• The wrist and the hand should be examined for evidence of nerve injury.
X-ray• The fracture is seen most clearly in the lateral view.• In an undisplaced fracture the ‘fat pad sign’ should raise suspicions: there is a triangular lucency in front of the distal humerus, due to the fat pad being pushed for-wards by a haematoma.
• In the common posteriorly displaced fracture the fracture line runs obliquely downwards and forwards and the distal fragment is tilted backwards and/or shifted backwards.• In the anteriorly displaced fracture the crack runs downwards and backwards and the distal fragment is tilted forwards.• On a normal lateral x-ray, a line drawn along the anterior cortex of the humerus should cross the middle of the capitulum.• If the line is anterior to the capitulum then a Type II fracture is suspected.
• An anteroposterior view is often difﬁcult to obtain without causing pain and may need to be postponed until the child has been anaesthetized.• It may show that the distal fragment is shifted or tilted sideways, and rotated (usually medially).• Measurement of Baumann’s angle is useful in assessing the degree of medial angulation before and after reduction (Fig. 24.30).
Treatment• If there is even a suspicion of a fracture, the elbow is gently splinted in 30 degrees of ﬂexion to prevent movement and possible neurovascular injury during the x-ray examination.
• TYPE I: UNDISPLACED FRACTURE• The elbow is immobilized at 90 degrees and neutral rotation in a light-weight splint or cast and the arm is supported by a sling.• It is essential to obtain an x-ray 5–7 days later to check that there has been no displacement.• The splint is retained for 3 weeks and supervised movement is then allowed.
• The capitulum normally angles forward about 30 degrees; if the capitulum is in a straight line with the humerus on the lateral x-ray, it will still remodel.• Even with Type I fractures, care must be taken to recognise any medial tilt of the distal fragment on the anteroposterior x-ray, otherwise cubitus varus can result.• Measure Baumann’s angle.
• TYPE II A: POSTERIORLY ANGULATED FRACTURE – MILD• In these cases swelling is usually not severe and the risk of vascular injury is low.• If the posterior cortices are in continuity, the fracture can be reduced under general anaesthesia by the following step-wise manoeuvre: – (1) traction for 2–3 minutes in the length of the arm with counter-traction above the elbow; – (2) correction of any sideways tilt or shift and rotation (in comparison with the other arm); – (3) gradual ﬂexion of the elbow to 120 degrees, and pronation of the forearm, while maintaining traction and exerting ﬁnger pressure behind the distal fragment to correct posterior tilt.
• Then feel the pulse and check the capillary return – if the distal circulation is suspect, immediately relax the amount of elbow ﬂexion until it improves.• X-rays are taken to conﬁrm reduction, checking carefully to see that there is no varus or valgus angulation and no rotational deformity.• The anteroposterior view is confusing and unreliable with the elbow ﬂexed, but the important features can be inferred by noting Baumann’s angle.
• Again, subtle medial tilt and rotation of the distal fragment must be recognised.• If the acutely ﬂexed position cannot be maintained without disturbing the circulation, or if the reduction is unstable, (and most of these fractures are unstable!) the fracture should be ﬁxed with percutaneous crossed K-wires (take care not to skewer the ulnar nerve!).
• Following reduction, the arm is held in a collar and cuff; the circulation should be checked repeatedly during the ﬁrst 24 hours.• An x-ray is obtained after 3–5 days to conﬁrm that the fracture has not slipped.• The splint is retained for 3 weeks, after which movements are begun.
• TYPES II B AND III: ANGULATED AND MALROTATED OR POSTERIORLY DISPLACED• These are usually associated with severe swelling, are difﬁcult to reduce and are often unstable; moreover, there is a considerable risk of neurovascular injury or circulatory compromise due to swelling.• The fracture should be reduced under general anaesthesia as soon as possible, by the method described above, and then held with percutaneous crossed K-wires; this obviates the necessity to hold the elbow acutely ﬂexed.
• Smooth wires should be used (this lessens the risk of physeal injury) and great care should be taken not to injure the ulnar, radial and median nerves.• Postoperative management is the same as for Type II A.
• OPEN REDUCTION• This is sometimes necessary for – (1) a fracture which simply cannot be reduced closed; – (2) an open fracture; or – (3) a fracture associated with vascular damage.• The fracture is exposed (preferably through two incisions, one on each side of the elbow), the haematoma is evacuated and the fracture is reduced and held by two crossed K-wires.
• CONTINUOUS TRACTION• Traction through a screw in the olecranon, with the arm held overhead, can be used – (1) if the fracture is severely displaced and cannot be reduced by manipulation; – (2) if, with the elbow ﬂexed 100 degrees, the pulse is obliterated and image intensiﬁcation is not available to allow pinning and then straightening of the elbow; or – (3) for severe open injuries or multiple injuries of the limb. Once the swelling subsides, a further attempt can be made at closed reduction.
• TREATMENT OF ANTERIORLY DISPLACED FRACTURES• This is a rare injury (less than 5 per cent of supra- condylar fractures).• However, ‘posterior’ fractures are sometimes inadvertently converted to ‘anterior’ ones by excessive traction and manipulation.• The fracture is reduced by pulling on the forearm with the elbow semi-ﬂexed, applying thumb pressure over the front of the distal fragment and then extending the elbow fully.• Crossed percutaneous pins are used if unstable.
• A posterior slab is bandaged on and retained for 3 weeks.• Thereafter, the child is allowed to regain ﬂexion gradually.
Complications• EARLY• Vascular injury• The great danger of supracondylar fracture is injury to the brachial artery, which, before the introduction of percutaneous pinning, was reported as occurring in over 5 per cent of cases.• Nowadays the incidence is probably less than 1 per cent.• Peripheral ischaemia may be immediate and severe, or the pulse may fail to return after reduction.• More commonly the injury is complicated by forearm oedema and a mounting compartment syndrome which leads to necrosis of the muscle and nerves without causing peripheral gangrene.
• Undue pain plus one positive sign (pain on passive extension of the ﬁngers, a tense and tender forearm, an absent pulse, blunted sensation or reduced capillary return on pressing the ﬁnger pulp) demands urgent action.• The ﬂexed elbow must be extended and all dressings removed.• If the circulation does not promptly improve, then angiography (on the operating table if it saves time) is carried out, the vessel repaired or grafted and a forearm fasciotomy performed.
• If angiography is not available, or would cause much delay, then Doppler imaging should be used.• In extreme cases, operative exploration would be justiﬁed on clinical criteria alone.
• Nerve injury• The radial nerve, median nerve (particularly the anterior interosseous branch) or the ulnar nerve may be injured.• Fortunately loss of function is usually temporary and recovery can be expected in 3 to 4 months.• If there is no recovery the nerve should be explored.
• However, if a nerve, documented as intact prior to manipulation, is then found to have failed after manipulation, then entrapment in the fracture is suspected and immediate exploration should be arranged.• The ulnar nerve may be damaged by careless pinning.• If the injury is recognized, and the pin removed, recovery will usually follow.
• LATE• Malunion• Malunion is common.• However, backward or sideways shifts are gradually smoothed out by modelling during growth and they seldom give rise to visible deformity of the elbow.• Forward or backward tilt may limit ﬂexion or extension, but consequent disability is slight.
• Uncorrected sideways tilt (angulation) and rotation are much more important and may lead to varus (or rarely valgus) deformity of the elbow; this is permanent and will not improve with growth (Fig. 24.32).• The fracture is extra-physeal and so physeal damage should not be blamed for the deformity; usually it is faulty reduction which is responsible.• Cubitus varus is disﬁguring and cubitus valgus may cause late ulnar palsy.• If deformity is marked, it will need correction by supracondylar osteotomy usually once the child approaches skeletal maturity.
• Elbow stiffness and myositis ossifﬁcans• Stiffness is an ever-present risk with elbow injuries.• Extension in particular may take months to return.• It must not be hurried.• Passive movement (which includes carrying weights) or forced movement is prohibited – this will only make matters worse and may contribute to the development of myositis ossiﬁcans.• As it is, myositis ossiﬁcans is extremely rare, and should remain so if rehabilitation is properly supervised.