Keywords
elbow - osteoarthritis - radius fractures
Introduction
Fractures of the radial head account over 50% of all fractures of the forearm. These
fractures occur with an indirect trauma through the long axis of the radius during
a fall with the forearm pronated and partially flexed.[1]
[2] Broberg and Morrey classify them in four types (modification of the Mason classification).
Type 1 fractures are non-displaced or minimally displaced (displaced by no more than
2 mm), and the size of the fragment should include up to 30% of the head (articular
surface). If the fracture is displaced by 2 mm or more or involve 30% of the head,
it is considered type 2. Type 3 are comminuted fractures. Finally, type 4 are the
fractures with elbow dislocation.[2]
[3]
Fractures type 1 are caused by low-energy trauma. They correspond to between 64 and
74% of all fractures of the radial head.[1]
[4] Taking into account its characteristics, type 1 fractures are considered stable
and do not present mechanical joint blockage. Also, clinically relevant associated
lesions are not common.[5] Because of all this, in this type of fracture, a non-operative management with a
short period of immobilization leads to a good clinical result without adverse outcomes.[4] Osteoarthritis of the radiocapitellar (RC OA) and ulnohumeral joint after the non-displaced
radial head fracture is uncommon.[6]
This case report presents a young patient diagnosed with isolated and non-displaced
radial head fracture that evolved 8 months later to global arthritis of the elbow.
Through revision about non-displaced radial head fracture, this article highlights
the importance of patient follow-up to recognize this possible complication, even
in injuries considered simple.
Case Report
A 35-year-old man, doorman, had a fall during soccer game. Three days after the injury,
the patient attended our hospital for medical care. In the physical examination, he
presented unremarkable swelling in the elbow and tenderness over the radial head.
Elbow stability was checked and ligament injury was not suspected. After radiography
and computed tomography, the patient was diagnosed with non-displaced radial head
fracture ([Fig. 1a], [b] and [Fig. 2a, b]).
Fig. 1 Initial radiographs of the elbow: anteroposterior (a) and lateral (b) views.
Fig. 2 Computed tomography showed a non-displaced and isolated radial head fracture: sagittal
(a) and coronal (b) views.
The initial treatment was a long arm cast for immobilization. As the patient had no
more pain after 7 days of immobilization, he stopped using the cast and returned to
his job. Two months later, the patient performed a new radiograph, which showed consolidation
with little deformity of the radial head and low degree of osteoarthrosis ([Fig. 3a, b]). However, just 6 months after that, the patient came to us with complaints of pain
and limitation of movement. During the physical examination, the patient presented
reduced range of motion (- 80° of extension and 110° of flexion) but had no important
limitation to the forearm rotation. Then, the patient performed new radiographs of
the elbow that evidenced severe elbow osteoarthritis ([Fig. 4a, b]). Then, he underwent arthroscopic debridement of the elbow, with an important improvement
in the range of motion and pain.
Fig. 3 Radiographs after 2 months of the injury showing fracture consolidation with little
deformity of the radial head and low degree of osteoarthrosis: anteroposterior (a) and lateral (b) views.
Fig. 4 Anteroposterior (a) and lateral (b) views of the elbow 8 months after the initial injury showing global and severe osteoarthritis.
Discussion
The main adverse outcomes related to non-displaced radial head fracture are elbow
stiffness and occasional elbow pain.[4]
[5]
[7] Elbow arthrosis after this type of fracture is rare.[6]
Herbertsson et al[7] evaluated the long-term outcomes of 27 Mason type 1 fractures and they reported
that although injured elbows had more degenerative changes than uninjured elbows,
these findings do not have clinical significance. The majority of the cases was free
of pain and presented no loss of motion. They also reported that injured elbows had
more radiologic deformities than uninjured elbows, but these deformities are not associated
with osteoarthritis. Kachooei et al[6] evaluated if patients after nonoperative treatment of an isolated radial head fracture
had RC OA. Of the 54 patients evaluated, 1 had an isolated RC OA and 3 also had ulnohumeral
osteoarthritis. They concluded, therefore, that RC OA is uncommon after these fractures,
even with some degree of deformity of the radial head.
Elbow stability should be checked in the initial physical examination to evaluate
ligamentous injuries, since the fracture of the radial head may be part of a complex
injury of the elbow. Kaas et al[5] reported associated lesions using magnetic resonance imaging (MRI) in 12 out of
17 patients with Mason type 1 fractures. In that study, they demonstrated that 47%
of the patients diagnosed with this type of fracture also had injury of the lateral
collateral ligament (LCL) and 2 out of 17 patients had chondral damage. Of these patients,
7 had a partial rupture and 1 had a complete rupture. Although these injuries are
seen in MRI, they are rarely symptomatic. Besides the LCL injury, interosseous membrane
(IOM) injuries are also commonly associated with Mason 1 fractures. Hausmann et al[8] screened 14 patients with Mason type 1 fractures for additional occult IOM lesion.
They reported that 9 out of 14 patients had additional lesions of the distal part
of the IOM. Since the patients may have additional lesions, it is probable that elbow
osteoarthritis after Mason 1 fracture had been part of a more complex ligamentous
injury.
In the case herewith presented, the patient was diagnosed with severe posttraumatic
arthrosis. However, in the initial physical examination, we did not suspect instability
due ligament injury. Therefore, since the patient suffered a high-energy trauma, it
is likely that he had a chondral lesion not diagnosed by the images. Another hypothesis
is that the patient had an undiagnosed ligament injury at the initial physical examination,
since examination for diagnosis of a subtle elbow ligament injury is not easy to reproduce.
In both hypotheses, an MRI of the elbow would probably have helped in this diagnosis
and, therefore, may be necessary whenever there is a high-energy trauma.
In conclusion, Mason type 1 radial head fractures are fractures with low risk for
developing osteoarthritis after conservative treatment. However, there is no guarantee
of favorable outcome. Whenever there is strong clinical suspicion of a more complex
injury, as in high-energy trauma, an MRI could be ordered, and the patient should
be followed up to identify a possible complication earlier.
