Fractures of the distal humerus in adults dnbid apleys (2)
FRACTURES OF THE DISTALHUMERUS IN ADULTS Dr. D. N. Bid [PT]
• Fractures around the elbow in adults – especially those of the distal humerus – are often high-energy injuries which are associated with vascular and nerve damage.• Some can be reduced and stabilized only by complex surgical techniques; and the tendency to stiffness of the elbow means that with all severe injuries the striving for anatomical perfection has to be weighed up against the realities of imperfect post-operative function.
• The AO-ASIF Group have defined three types of distal humeral fracture: – Type A – an extra-articular supracondylar fracture; – Type B – an intra-articular unicondylar fracture (one condyle sheared off); – Type C – bicondylar fractures with varying degrees of comminution. [Association for Osteosynthesis / Association for the Study of Internal Fixation]
Figure 1- Illustrated AO/OTA classification of distal humerus fractures: type A, extra-articular;type B, partial articular; and type C, complete articular. Each type has further subdivisionsbased on the increasing complexity of the fracture pattern.
TYPE A – SUPRACONDYLAR FRACTURES• These extra-articular fractures are rare in adults.• When they do occur, they are usually displaced and unstable – probably because there is no tough periosteum to tether the fragments.• In high-energy injuries there may be comminution of the distal humerus.
Treatment• Closed reduction is unlikely to be stable and K- wire fixation is not strong enough to permit early mobilization.• Open reduction and internal fixation is therefore the treatment of choice.• The distal humerus is approached through a posterior exposure.
• It is sometimes possible to fix the fracture without recourse to an olecranon osteotomy or triceps reﬂection.• A simple transverse or oblique fracture can usually be reduced and fixed with a pair of contoured plates and screws.
TYPES B AND C – INTRA-ARTICULAR FRACTURES• Except in osteoporotic individuals, intra- articular condylar fractures should be regarded as high-energy injuries with soft- tissue damage.• A severe blow on the point of the elbow drives the olecranon process upwards, splitting the condyles apart.
• Swelling is considerable, but if the bony landmarks can be felt the elbow is found to be distorted.• The patient should be carefully examined for evidence of vascular or nerve injury; if there are signs of vascular insufficiency, this must be addressed as a matter of urgency.
X-Ray• The fracture extends from the lower humerus into the elbow joint; it may be difficult to tell whether one or both condyles are involved, especially with an undisplaced condylar fracture.• There is often also comminution of the bone between the condyles, the extent of which is usually underestimated.
• Sometimes the fracture extends into the metaphysis as a T- or Y-shaped break, or else there may be multiple fragments (comminution).• The lesson is: ‘Prepare for the worst before operating’.• CT scans can be helpful in planning the surgical approach.
• Treatment• These are severe injuries associated with joint damage; prolonged immobilization will certainly result in a stiff elbow.• Early movement is therefore a prime objective.
• Undisplaced fractures• These can be treated by applying a posterior slab with the elbow ﬂexed almost 90 degrees; movements are commenced after 2 weeks.• However, great care should be taken to avoid the dual pitfalls of: underdiagnosis (displacement and comminution are not always obvious on the initial x-ray) and late displacement (always obtain check x-rays a week after injury).
• Postoperatively the elbow is held at 90 degrees with the arm supported in a sling.• Movement is encouraged but should never be forced.• Fracture healing usually occurs by 12 weeks.• Despite the best efforts, the patient often does not regain full extension and in the most severe cases movement may be severely restricted.
• Displaced Type B and C fractures• If the appropriate expertise and facilities are available, open reduction and internal fixation is the treatment of choice for displaced fractures (some would say for all Type B and C fractures – minor displacement is easily overlooked in the early post-injury x-rays).• The danger with conservative treatment is the strong tendency to stiffening of the elbow and persistent pain.
• Good exposure of the joint is needed, if necessary by performing an intra-articular olecranon osteotomy.• The ulnar nerve should be identified and protected throughout.• The fragments are reduced and held temporarily with K- wires.• A unicondylar fracture without comminution can then be fixed with screws; if the fragment is large, a contoured plate is added to prevent redisplacement.
• First the articular block is reconstructed with a transverse screw; bone graft is sometimes needed.• The distal block is then fixed to the humeral shaft with medial and lateral plates.• Pre-contoured plates with locking screws are now available.• These hold the distal fragments more effectively.
• A description of this sort fails to convey the real difficulty of these operations.• Unless the surgeon is more than usually skilful, the elbow may end up stiffer than if treated by activity (see below).
• Figure 4 Techniques for internal fixation of the distal humerus. A,T-condylar fracture of the distal humerus. B, Reduction of both condyles with K-wire fixation. The intra-articular fragments are reduced first. C, Compression screw fixation of the condyles and medial and lateral condyle to the distal humerus. Cannulated screws are helpful here.D, Medial and lateral condylar plate fixation of the condyle to the distal shaft of the humerus. E, Y-plate fixation of the humeral shaft to the condyles of the humerus.
• ALTERNATIVE METHODS OF TREATMENT• If it is anticipated that the outcome of operative treatment will be poor (either because of the degree of comminution and soft-tissue damage or because of lack of expertise and facilities) other options can be considered.• Elbow replacement• The elderly patient with a comminuted fracture, a low transverse fracture or osteopaenic bone, may be best served by replacement of the elbow.
• The ‘bag of bones’ technique• The arm is held in a collar and cuff or, better, a hinged brace, with the elbow ﬂexed above a right angle; active movements are encouraged as soon as the patient is willing.• The fracture usually unites within 6–8 weeks, but exercises are continued far longer.• A useful range of movement (45–90 degrees) is often obtained.
• Skeletal traction• An alternative method of treating either moderately displaced or severely comminuted fractures is by skeletal traction through the olecranon (beware the ulnar nerve!); the patient remains in bed with the humerus held vertical, and elbow movements are encouraged.• Again, meticulous internal fixation or elbow replacement are usually preferable.
Complications• EARLY COMPLICATIONS• Vascular injury – Always check the circulation (repeatedly!). – Vigilance is required to make the diagnosis and institute treatment as early as possible.• Nerve injury – There may be damage to either the median or the ulnar nerve. – It is important to examine the hand and record the findings before treatment is commenced. – The ulnar nerve is particularly vulnerable during surgery.
• LATE COMPLICATIONS• Stiffness – Comminuted fractures of the elbow always result in some degree of stiffness. – However, the disability may be reduced by encouraging an energetic exercise programme. – Late operations to improve elbow movement are difficult but can be rewarding.• Heterotopic ossification – Severe soft-tissue damage may lead to heterotopic ossification. – Forced movement should be avoided.
Intraarticular Type C Fracture of the Distal Humerus.flv