VOL 46: SEPTEMBER • SEPTEMBRE 2000❖Canadian Family Physician•Le Médecin de famille canadien 1759
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Dr Schubert practises emergency medicine at the University of British Columbia Hospital in Vancouver.
Emergency Case
QUESTIONS
A man fell from a ladder and presented with pain in his elbow and inability to straighten his arm. What historical and clinical features suggest radial head fracture? What injuries are often associated with it? Which treatments are recommended?
R
adial head fractures are frequently seen in emer- gency departments and are the third most com- mon fracture (after Colles’ and scaphoid) resulting from falls on outstretched hands. They are the most common elbow fracture.Mechanism of injur y
Radial head fractures have a mechanism dif- ferent from Colles’ or scaphoid fractures.
Radial head fracture likely results from falling on the hand with the forear m in supination and some valgus force.1 This positioning transfers force up the shaft of the radius and causes the radial head to strike the capitulum.
Occasionally, radial head fracture results from a direct blow to the radial head area.
Examination
Examination of the elbow shows joint effusion, which is palpable as a fluid-filled bulge between the lateral
humeral condyle and the olecranon.2The radial head can be directly palpated for tenderness 2 to 3 cm dis- tal to the lateral epicondyle with the elbow at 90oflex- ion. Tender ness at the epicondyles indicates epicondyle fracture or collateral ligament injury.
Range of motion is reduced in all spheres.
Extremes of flexion and, most notably, extension increase intra-ar ticular pressure when there is hemar throsis and are, therefore, limited by pain.
Supination and pronation cause movement in the area of the fracture and are painful. To evaluate the stabili- ty of the elbow, collateral ligaments must be assessed;
this is best done after insuring that an epicondyle fracture is not present (ie, after x-ray films are viewed). Testing for laxity of ligaments might need to be repeated in several days after pain sub- sides. Examination of the ar m above and below the elbow is impor tant; injur y at the distal forearm and wrist might go unno- ticed by patients due to the predominant pain in their elbows.
Neurovascular exami- nation should include sensor y assessment in median, ulnar, and radial ner ve areas of the hand.
The most common associated injury is ulnar collateral ligament injury at the elbow.1Less frequently, distal radioulnar ligaments are injured, which can result in axial instability of the forearm. Fractures most often associated with radial head fracture are scaphoid and capitulum fractures.
F i g u re 1. Elbow fat pads with intra-articular fracture
Radial head fracture
Harold Schubert, MD, MSC, CCFP
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Imaging
Imaging the elbow includes stan- dard anteroposterior (AP), lateral, and oblique radiographs. Radial head fractures are most often seen on AP or oblique views and are commonly subtle or not visible at all.
The only radiographic sign of fracture might be the posterior fat pad, seen on the lateral view.3The anterior fat pad can be seen in nor- mal elbows, but seeing a posterior
fat pad is abnormal. The posterior fat pad, located between the poste- rior humeral condyles (olecranon fossa), is pushed out of its bony recess by hemarthrosis. This “fat pad sign” is seen in 90% of chil- dren’s and adolescents’ intra-artic- ular fractures. It is less frequently seen in adults with similar frac- tures; its absence does not exclude fracture.3 Figure 1 illustrates the anterior and posterior fat pads usu- ally seen with intra-articular elbow
fractures. When radial head frac- ture is suspected but not radi- ographically visible, repeat x-ray examination in 10 to 14 days is indicated.
Computed tomography scan allows visualization of subtle radial head fractures not seen on plain x- ray films. Although CT is usually not necessary or cost-effective, it is indicated and helpful for complex injuries where location and origin of fragments require clarification.
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1760 Canadian Family Physician•Le Médecin de famille canadien❖VOL 46: SEPTEMBER • SEPTEMBRE 2000
Type I Undisplaced fissure or marginal fracture
Type Ia Radial neck fracture: minimal angulation or impaction Type Ib Vertical shear: less than 2 mm incongruity
Type II Displaced marginal fracture
Type IIa Radial neck fracture: marked angulation or impaction Type IIb Vertical shear: more than 2 mm displacement Type III Comminuted fracture of the whole radial head
Classification system from Mason.4
F i g u re 2.Classification of radial head fractures
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Classification
Classifying radial head fractures (Figure 24) aids in treatment.
Likelihood of associated injur y increases with severity of fracture.
Some authors have added a Type IV: radial head fracture with dislo- cation of the elbow.
Treatment
Treatment for radial head frac- ture, as with any injur y, aims to achieve symptom-free full function as quickly as possible. Elbow immobilization quickly results in flexion contracture; immobiliza- tion for 3 weeks has been associat- ed with 10oto 25opermanent loss of elbow extension and a lesser loss of flexion.5 Range of supina- tion or pronation is also reduced.
Nonunion, which occurs fairly often, is not a concern for radial head fracture; it is usually asymp- tomatic.
Type Ia and Ib fractures . Treatment for Type Ia and Ib frac- tures is symptomatic, with sling, ice, and analgesics during the ini- tial (inflammatory) phase of heal- ing. As the hemarthrosis subsides, pain lessens and range of motion returns to normal. Mobilization as soon as pain allows is of the utmost impor tance. Undisplaced radial head fractures are very stable and will not displace with normal use of the arm. Full range of motion should return in 7 to 10 days. Any delay raises concer n for other occult injury in the elbow, such as capitulum osteochondral fracture, and should be investigated.
Type II fractures. Treatment for Type II fractures—whether to treat open or closed—has been contro- versial and the subject of many studies. Orthopedic consultation is
advisable. A reasonable approach for many Type II fractures is to treat closed and aim for early mobi- lization; delay in achieving this objective can be addressed surgi- cally if necessary by reduction and screw fixation of fractured parts or radial head resection.6Aspiration of elbow hemarthrosis and injec- tion of anesthetic can be helpful with Type II fractures to assess for possible mechanical block to full range of motion.
Type III fractures. Type III frac- tures are considered incompatible with satisfactor y elbow function unless radial head fragments are resected. This surgical treatment restores arm function and has been regarded as relatively benign. Resection of the radial head is, however, often associated with untoward consequences, including loss of range of motion due to longer immobilization, mild arthritis in the elbow, subluxation of the distal radioulnar joint, proxi- mal migration of the radius, and increased valgus angulation at the elbow.5 Functional deficits result- ing from these anatomic changes have not been well studied. Some authors advocate replacement of Type III fractured radial heads with prostheses. Whether this produces results sufficiently supe- rior to justify the risks is a matter of debate.
ANSWERS
Radial head fracture is suggested by a histor y of falling on an out- stretched hand, pain in the elbow, joint effusion, and an inability to fully extend the elbow. Ulnar col- lateral ligament injur y at the elbow is the injury most common- ly associated with radial head
fracture. T ype I fractures are treated symptomatically, with mobilization as soon as possible;
Type II fractures can be treat- ed symptomatically, but some require surger y; Type III frac- t u r e s r e q u i r e r a d i a l h e a d resection.
References
1. Davidson PA, Moseley BJ Jr, Tullos HS. Radial head fracture: a potentially complex injury. Clin Orthop
1993;297:224-30.
2. Eiff MP, Hatch RL, Calmbach WL.
Fracture management for primary care.
Philadelphia, Pa: WB Saunders Co;
1998.
3. Norell HG. Roentgenologic visualiza- tion of the extracapsular fat; its impor- tance in the diagnosis of traumatic injuries to the elbow. Acta Radiol 1954;42:205-10.
4. Mason ML. Some observations on fractures of the head of the radius with a review of one hundred cases. Br J Surg1954;42:123-32.
5. Coleman DA, Blair WF, Shurr D.
Resection of the radial head for frac- ture of the radial head. J Bone Joint Surg Am1987;69A(3):385-92.
6. Broberg MA, Morrey BF. Results of delayed excision of the radial head after fracture. J Bone Joint Surg Am 1986;68A(5):669-74.
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